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Sample records for regulate cd44 adhesiveness

  1. LRP-1–CD44, a New Cell Surface Complex Regulating Tumor Cell Adhesion

    PubMed Central

    Perrot, Gwenn; Langlois, Benoit; Devy, Jérôme; Jeanne, Albin; Verzeaux, Laurie; Almagro, Sébastien; Sartelet, Hervé; Hachet, Cathy; Schneider, Christophe; Sick, Emilie; David, Marion; Khrestchatisky, Michel; Emonard, Hervé; Martiny, Laurent

    2012-01-01

    The low-density lipoprotein receptor-related protein 1 (LRP-1) is a large endocytic receptor mediating the clearance of various molecules from the extracellular matrix. In the field of cancer, LRP-1-mediated endocytosis was first associated with antitumor properties. However, recent results suggested that LRP-1 may coordinate the adhesion-deadhesion balance in malignant cells to support tumor progression. Here, we observed that LRP-1 silencing or RAP (receptor-associated protein) treatment led to accumulation of CD44 at the tumor cell surface. Moreover, we evidenced a tight interaction between CD44 and LRP-1, not exclusively localized in lipid rafts. Overexpression of LRP-1-derived minireceptors indicated that the fourth ligand-binding cluster of LRP-1 is required to bind CD44. Labeling of CD44 with EEA1 and LAMP-1 showed that internalized CD44 is routed through early endosomes toward lysosomes in a LRP-1-dependent pathway. LRP-1-mediated internalization of CD44 was highly reduced under hyperosmotic conditions but poorly affected by membrane cholesterol depletion, revealing that it proceeds mostly via clathrin-coated pits. Finally, we demonstrated that CD44 silencing abolishes RAP-induced tumor cell attachment, revealing that cell surface accumulation of CD44 under LRP-1 blockade is mainly responsible for the stimulation of tumor cell adhesion. Altogether, our data shed light on the LRP-1-mediated internalization of CD44 that appeared critical to define the adhesive properties of tumor cells. PMID:22711991

  2. Cleavage of Hyaluronan and CD44 Adhesion Molecule Regulate Astrocyte Morphology via Rac1 Signalling

    PubMed Central

    Konopka, Anna; Zeug, Andre; Skupien, Anna; Kaza, Beata; Mueller, Franziska; Chwedorowicz, Agnieszka; Ponimaskin, Evgeni; Wilczynski, Grzegorz M.; Dzwonek, Joanna

    2016-01-01

    Communication of cells with their extracellular environment is crucial to fulfill their function in physiological and pathophysiological conditions. The literature data provide evidence that such a communication is also important in case of astrocytes. Mechanisms that contribute to the interaction between astrocytes and extracellular matrix (ECM) proteins are still poorly understood. Hyaluronan is the main component of ECM in the brain, where its major receptor protein CD44 is expressed by a subset of astrocytes. Considering the fact that functions of astrocytes are tightly coupled with changes in their morphology (e.g.: glutamate clearance in the synaptic cleft, migration, astrogliosis), we investigated the influence of hyaluronan cleavage by hyaluronidase, knockdown of CD44 by specific shRNA and CD44 overexpression on astrocyte morphology. Our results show that hyaluronidase treatment, as well as knockdown of CD44, in astrocytes result in a “stellate”-like morphology, whereas overexpression of CD44 causes an increase in cell body size and changes the shape of astrocytes into flattened cells. Moreover, as a dynamic reorganization of the actin cytoskeleton is supposed to be responsible for morphological changes of cells, and this reorganization is controlled by small GTPases of the Rho family, we hypothesized that GTPase Rac1 acts as a downstream effector for hyaluronan and CD44 in astrocytes. We used FRET-based biosensor and a dominant negative mutant of Rac1 to investigate the involvement of Rac1 activity in hyaluronidase- and CD44-dependent morphological changes of astrocytes. Both, hyaluronidase treatment and knockdown of CD44, enhances Rac1 activity while overexpression of CD44 reduces the activity state in astrocytes. Furthermore, morphological changes were blocked by specific inhibition of Rac1 activity. These findings indicate for the first time that regulation of Rac1 activity is responsible for hyaluronidase and CD44-driven morphological changes of

  3. CD44 sensitivity of platelet activation, membrane scrambling and adhesion under high arterial shear rates.

    PubMed

    Liu, Guilai; Liu, Guoxing; Alzoubi, Kousi; Chatterjee, Madhumita; Walker, Britta; Münzer, Patrick; Luo, Dong; Umbach, Anja T; Elvira, Bernat; Chen, Hong; Voelkl, Jakob; Föller, Michael; Mak, Tak W; Borst, Oliver; Gawaz, Meinrad; Lang, Florian

    2016-01-01

    CD44 is required for signalling of macrophage migration inhibitory factor (MIF), an anti-apoptotic pro-inflammatory cytokine. MIF is expressed and released from blood platelets, key players in the orchestration of occlusive vascular disease. Nothing is known about a role of CD44 in the regulation of platelet function. The present study thus explored whether CD44 modifies degranulation (P-selectin exposure), integrin activation, caspase activity, phosphatidylserine exposure on the platelet surface, platelet volume, Orai1 protein abundance and cytosolic Ca(2+)-activity ([Ca2+]i). Platelets from mice lacking CD44 (cd44(-/-)) were compared to platelets from corresponding wild-type mice (cd44(+/+)). In resting platelets, P-selectin abundance, α(IIb)β3 integrin activation, caspase-3 activity and phosphatidylserine exposure were negligible in both genotypes and Orai1 protein abundance, [Ca2+]i, and volume were similar in cd44(-/-) and cd44(+/+) platelets. Platelet degranulation and α(IIb)β3 integrin activation were significantly increased by thrombin (0.02 U/ml), collagen related peptide (CRP, 2 µg/ml and Ca(2+)-store depletion with thapsigargin (1 µM), effects more pronounced in cd44(-/-) than in cd44(+/+) platelets. Thrombin (0.02 U/ml) increased platelet [Ca2+]i, caspase-3 activity, phosphatidylserine exposure and Orai1 surface abundance, effects again significantly stronger in cd44(-/-) than in cd44(+/+) platelets. Thrombin further decreased forward scatter in cd44(-/-) and cd44(+/+) platelets, an effect which tended to be again more pronounced in cd44(-/-) than in cd44(+/+) platelets. Platelet adhesion and in vitro thrombus formation under high arterial shear rates (1,700 s(-1)) were significantly augmented in cd44(-/-) mice. In conclusion, genetic deficiency of CD44 augments activation, apoptosis and pro-thrombotic potential of platelets. PMID:26355696

  4. CD44-mediated Adhesion to Hyaluronic Acid Contributes to Mechanosensing and Invasive Motility

    PubMed Central

    Kim, Yushan; Kumar, Sanjay

    2014-01-01

    The high molecular weight glycosaminoglycan, hyaluronic acid (HA), makes up a significant portion of the brain extracellular matrix (ECM). Glioblastoma multiforme (GBM), a highly invasive brain tumor, is associated with aberrant HA secretion, tissue stiffening, and overexpression of the HA receptor CD44. Here, transcriptomic analysis, engineered materials, and measurements of adhesion, migration, and invasion were used to investigate how HA/CD44 ligation contributes to the mechanosensing and invasive motility of GBM tumor cells, both intrinsically and in the context of RGD/integrin adhesion. Analysis of transcriptomic data from The Cancer Genome Atlas (TCGA) reveals up-regulation of transcripts associated with HA/CD44 adhesion. CD44 suppression in culture reduces cell adhesion to HA on short time scales (0.5h post-incubation) even if RGD is present, whereas maximal adhesion on longer time scales (3h) requires both CD44 and integrins. Moreover, time-lapse imaging demonstrates that cell adhesive structures formed during migration on bare HA matrices are more short-lived than cellular protrusions formed on surfaces containing RGD. Interestingly, adhesion and migration speed were dependent on HA hydrogel stiffness, implying that CD44-based signaling is intrinsically mechanosensitive. Finally, CD44 expression paired with an HA-rich microenvironment maximized three-dimensional invasion, whereas CD44 suppression or abundant integrin-based adhesion limited it. These findings demonstrate that CD44 transduces HA-based stiffness cues, temporally precedes integrin-based adhesion maturation, and facilitates invasion. PMID:24962319

  5. Phosphatidylinositol 4,5-Bisphosphate Clusters the Cell Adhesion Molecule CD44 and Assembles a Specific CD44-Ezrin Heterocomplex, as Revealed by Small Angle Neutron Scattering

    DOE PAGESBeta

    Khajeh, Jahan Ali; Ju, Jeong Ho; Gupta, Yogesh K.; Stanley, Christopher B.; Do, Changwoo; Heller, William T.; Aggarwal, Aneel K.; Callaway, David J.E.; Bu, Zimei

    2015-01-08

    The cell adhesion molecule CD44 regulates diverse cellular functions, including cell-cell and cell-matrix interaction, cell motility, migration, differentiation, and growth. In cells, CD44 co-localizes with the membrane-cytoskeleton adapter protein Ezrin, which links the CD44 assembled receptor signaling complexes to the cytoskeletal actin and organizes the spatial and temporal localization of signaling events. Here we report that the cytoplasmic tail of CD44 (CD44ct) is largely disordered and adopts an autoinhibited conformation, which prevents CD44ct from binding directly to activated Ezrin in solution. Binding to the signaling lipid phosphatidylinositol 4,5-biphosphlate (PIP2) disrupts autoinhibition in CD44ct, and activates CD44ct to associate with Ezrin.more » Further, using contrast variation small angle neutron scattering, we show that PIP2 mediates the assembly of a specific hetero-tetramer complex of CD44ct with Ezrin. This study reveals a novel autoregulation mechanism in the cytoplasmic tail of CD44 and the role of PIP2 in mediating the assembly of multimeric CD44ct-Ezrin complexes. We hypothesize that polyvalent electrostatic interactions are responsible for the assembly of multimeric PIP2-CD44-Ezrin complexes.« less

  6. Phosphatidylinositol 4,5-Bisphosphate Clusters the Cell Adhesion Molecule CD44 and Assembles a Specific CD44-Ezrin Heterocomplex, as Revealed by Small Angle Neutron Scattering*

    PubMed Central

    Chen, Xiaodong; Khajeh, Jahan Ali; Ju, Jeong Ho; Gupta, Yogesh K.; Stanley, Christopher B.; Do, Changwoo; Heller, William T.; Aggarwal, Aneel K.; Callaway, David J. E.; Bu, Zimei

    2015-01-01

    The cell adhesion molecule CD44 regulates diverse cellular functions, including cell-cell and cell-matrix interaction, cell motility, migration, differentiation, and growth. In cells, CD44 co-localizes with the membrane-cytoskeleton adapter protein Ezrin that links the CD44 assembled receptor signaling complexes to the cytoskeletal actin network, which organizes the spatial and temporal localization of signaling events. Here we report that the cytoplasmic tail of CD44 (CD44ct) is largely disordered. Upon binding to the signaling lipid phosphatidylinositol 4,5-bisphosphate (PIP2), CD44ct clusters into aggregates. Further, contrary to the generally accepted model, CD44ct does not bind directly to the FERM domain of Ezrin or to the full-length Ezrin but only forms a complex with FERM or with the full-length Ezrin in the presence of PIP2. Using contrast variation small angle neutron scattering, we show that PIP2 mediates the assembly of a specific heterotetramer complex of CD44ct with Ezrin. This study reveals the role of PIP2 in clustering CD44 and in assembling multimeric CD44-Ezrin complexes. We hypothesize that polyvalent electrostatic interactions are responsible for the assembly of CD44 clusters and the multimeric PIP2-CD44-Ezrin complexes. PMID:25572402

  7. Phosphatidylinositol 4,5-Bisphosphate Clusters the Cell Adhesion Molecule CD44 and Assembles a Specific CD44-Ezrin Heterocomplex, as Revealed by Small Angle Neutron Scattering

    SciTech Connect

    Khajeh, Jahan Ali; Ju, Jeong Ho; Gupta, Yogesh K.; Stanley, Christopher B.; Do, Changwoo; Heller, William T.; Aggarwal, Aneel K.; Callaway, David J.E.; Bu, Zimei

    2015-01-08

    The cell adhesion molecule CD44 regulates diverse cellular functions, including cell-cell and cell-matrix interaction, cell motility, migration, differentiation, and growth. In cells, CD44 co-localizes with the membrane-cytoskeleton adapter protein Ezrin, which links the CD44 assembled receptor signaling complexes to the cytoskeletal actin and organizes the spatial and temporal localization of signaling events. Here we report that the cytoplasmic tail of CD44 (CD44ct) is largely disordered and adopts an autoinhibited conformation, which prevents CD44ct from binding directly to activated Ezrin in solution. Binding to the signaling lipid phosphatidylinositol 4,5-biphosphlate (PIP2) disrupts autoinhibition in CD44ct, and activates CD44ct to associate with Ezrin. Further, using contrast variation small angle neutron scattering, we show that PIP2 mediates the assembly of a specific hetero-tetramer complex of CD44ct with Ezrin. This study reveals a novel autoregulation mechanism in the cytoplasmic tail of CD44 and the role of PIP2 in mediating the assembly of multimeric CD44ct-Ezrin complexes. We hypothesize that polyvalent electrostatic interactions are responsible for the assembly of multimeric PIP2-CD44-Ezrin complexes.

  8. Adhesion glycoprotein CD44 functions as an upstream regulator of a network connecting ERK, AKT and Hippo-YAP pathways in cancer progression

    PubMed Central

    Wu, Chenxi; Wu, Lele; Wang, Yuzhi; Liu, Yan; Yu, Zhenghong; Qin, Sheng; Ma, Fei; Thiery, Jean Paul; Chen, Liming

    2015-01-01

    Targeted therapies are considered to be the future of cancer treatment. However, the mechanism through which intracellular signaling pathways coordinate to modulate oncogenesis remains to be elucidated. In this study, we describe a novel crosstalk among ERK, AKT and Hippo-YAP pathways, with CD44 as an upstream regulator. High cell density leads to activation of ERK and AKT but inactivation of YAP in cancer cells. CD44 modulates cell proliferation and cell cycle but not apoptosis. The expression and activity of cell cycle genes were cooperatively regulated by ERK, AKT and Hippo-YAP signaling pathways through CD44-mediated mechanisms. In addition, CD44 depletion abrogates cancer stem cell properties of tumor initiating cells. Taken together, we described a paradigm where CD44 functions as an upstream regulator sensing the extracellular environment to modulate ERK, AKT and Hippo-YAP pathways which cooperatively control downstream gene expression to modulate cell contact inhibition of proliferation, cell cycle progression and maintenance of tumor initiating cells. Our current study provides valuable information to design targeted therapeutic strategies in cancers. PMID:25605020

  9. Chondroitin sulfate addition to CD44H negatively regulates hyaluronan binding

    SciTech Connect

    Ruffell, Brian; Johnson, Pauline . E-mail: pauline@interchange.ubc.ca

    2005-08-26

    CD44 is a widely expressed cell adhesion molecule that binds hyaluronan, an extracellular matrix glycosaminoglycan, in a tightly regulated manner. This regulated interaction has been implicated in inflammation and tumor metastasis. CD44 exists in the standard form, CD44H, or as higher molecular mass isoforms due to alternative splicing. Here, we identify serine 180 in human CD44H as the site of chondroitin sulfate addition and show that lack of chondroitin sulfate addition at this site enhances hyaluronan binding by CD44. A CD44H-immunoglobulin fusion protein expressed in HEK293 cells, and CD44H expressed in murine L fibroblast cells were modified by chondroitin sulfate, as determined by reduced sulfate incorporation after chondroitinase ABC treatment. Mutation of serine 180 or glycine 181 in CD44H reduced chondroitin sulfate addition and increased hyaluronan binding, indicating that serine 180 is the site for chondroitin sulfate addition in CD44H and that this negatively regulates hyaluronan binding.

  10. 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

  11. Evidence of a Role for CD44 and Cell Adhesion in Mediating Resistance to Lenalidomide in Multiple Myeloma: Therapeutic Implications

    PubMed Central

    Bjorklund, Chad C.; Baladandayuthapani, Veerabhadran; Lin, Heather Y.; Jones, Richard J.; Kuiatse, Isere; Wang, Hua; Yang, Jing; Shah, Jatin J.; Thomas, Sheeba K.; Wang, Michael; Weber, Donna M.; Orlowski, Robert Z.

    2013-01-01

    Resistance of myeloma to lenalidomide is an emerging clinical problem, and though it has been associated in part with activation of Wnt/β-catenin signaling, the mediators of this phenotype remained undefined. Lenalidomide-resistant models were found to overexpress the hyaluronan (HA)-binding protein CD44, a downstream Wnt/β-catenin transcriptional target. Consistent with a role of CD44 in cell adhesion-mediated drug-resistance (CAM-DR), lenalidomide-resistant myeloma cells were more adhesive to bone marrow stroma and HA-coated plates. Blockade of CD44 with monoclonal antibodies, free HA, or CD44 knockdown reduced adhesion and sensitized to lenalidomide. Wnt/β-catenin suppression by FH535 enhanced the activity of lenalidomide, as did interleukin-6 neutralization with siltuximab. Notably, all-trans-retinoic acid (ATRA) down-regulated total β-catenin, cell-surface and total CD44, reduced adhesion of lenalidomide-resistant myeloma cells, and enhanced the activity of lenalidomide in a lenalidomide-resistant in vivo murine xenograft model. Finally, ATRA sensitized primary myeloma samples from patients that had relapsed and/or refractory disease after lenalidomide therapy to this immunomodulatory agent ex vivo. Taken together, our findings support the hypotheses that CD44 and CAM-DR contribute to lenalidomide-resistance in multiple myeloma, that CD44 should be evaluated as a putative biomarker of sensitivity to lenalidomide, and that ATRA or other approaches that target CD44 may overcome clinical lenalidomide resistance. PMID:23760401

  12. CD44 and the adhesion of neoplastic cells.

    PubMed Central

    Rudzki, Z; Jothy, S

    1997-01-01

    CD44 is a family of transmembrane glycoproteins that act mainly as a receptor for hyaluronan. It can also bind some other extracellular matrix ligands (chondroitin sulphate, heparan sulphate, fibronectin, serglycin, osteopontin) with lower affinity. CD44 is encoded by a single gene containing 20 exons, 10 of which (v1-v10) are variant exons inserted by alternative splicing. The standard, ubiquitously expressed isoform of CD44, does not contain sequences encoded by these variant exons. Numerous variant isoforms of CD44 containing different combinations of exons v1-v10 inserted into the extracellular domain can be expressed in proliferating epithelial cells and activated lymphocytes. CD44 plays a significant role in lymphocyte homing. Both alternative splicing and glycosylation influence receptor function of the molecule, usually reducing its affinity to hyaluronan. The cytoplasmic domain of CD44 communicates with the cytoskeleton via ankyrin and proteins belonging to the ezrin-moesin-radixin family. Relatively little is known about the intracellular events following interactions of CD44 with its ligands. Some variant isoforms, especially those containing sequences encoded by v6-v10, are overexpressed in both human and animal neoplasms. In a rat pancreatic adenocarcinoma model one of the variant CD44 isoforms was proved to be determinant in the metastatic process. For some human neoplasms (carcinomas of the digestive tract, non-Hodgkin's lymphomas, thyroid carcinomas, and others) correlations have been made between the particular pattern of CD44 variants produced by neoplastic cells and clinicopathological parameters of tumours, such as grade, stage, presence of metastases, and survival. In vitro studies indicate that modifications of CD44 expression result in different ligand recognition and influence cell motility, invasive properties, and metastatic potential of experimental tumours. Investigation of CD44 neoexpression can be useful both in early cancer diagnosis

  13. The adhesion receptor CD44 promotes atherosclerosis by mediating inflammatory cell recruitment and vascular cell activation

    PubMed Central

    Cuff, Carolyn A.; Kothapalli, Devashish; Azonobi, Ijeoma; Chun, Sam; Zhang, Yuanming; Belkin, Richard; Yeh, Christine; Secreto, Anthony; Assoian, Richard K.; Rader, Daniel J.; Puré, Ellen

    2001-01-01

    Atherosclerosis causes most acute coronary syndromes and strokes. The pathogenesis of atherosclerosis includes recruitment of inflammatory cells to the vessel wall and activation of vascular cells. CD44 is an adhesion protein expressed on inflammatory and vascular cells. CD44 supports the adhesion of activated lymphocytes to endothelium and smooth muscle cells. Furthermore, ligation of CD44 induces activation of both inflammatory and vascular cells. To assess the potential contribution of CD44 to atherosclerosis, we bred CD44-null mice to atherosclerosis-prone apoE-deficient mice. We found a 50–70% reduction in aortic lesions in CD44-null mice compared with CD44 heterozygote and wild-type littermates. We demonstrate that CD44 promotes the recruitment of macrophages to atherosclerotic lesions. Furthermore, we show that CD44 is required for phenotypic dedifferentiation of medial smooth muscle cells to the “synthetic” state as measured by expression of VCAM-1. Finally, we demonstrate that hyaluronan, the principal ligand for CD44, is upregulated in atherosclerotic lesions of apoE-deficient mice and that the low-molecular-weight proinflammatory forms of hyaluronan stimulate VCAM-1 expression and proliferation of cultured primary aortic smooth muscle cells, whereas high-molecular-weight forms of hyaluronan inhibit smooth muscle cell proliferation. We conclude that CD44 plays a critical role in the progression of atherosclerosis through multiple mechanisms. PMID:11581304

  14. Alternatively spliced variants of the cell adhesion molecule CD44 and tumour progression in colorectal cancer.

    PubMed Central

    Gotley, D. C.; Fawcett, J.; Walsh, M. D.; Reeder, J. A.; Simmons, D. L.; Antalis, T. M.

    1996-01-01

    Increased expression of alternatively spliced variants of the CD44 family of cell adhesion molecules has been associated with tumour metastasis. In the present study, expression of alternatively spliced variants of CD44 and their cellular distribution have been investigated in human colonic tumours and in the corresponding normal mucosa, in addition to benign adenomatous polyps. The expression of CD44 alternatively spliced variants has been correlated with tumour progression according to Dukes' histological stage. CD44 variant expression was determined by immunohistochemisty using monoclonal antibodies directed against specific CD44 variant domains together with RT-PCR analysis of CD44 variant mRNA expression in the same tissue specimens. We demonstrate that as well as being expressed in colonic tumour cells, the full range of CD44 variants, CD44v2-v10, are widely expressed in normal colonic crypt epithelium, predominantly in the crypt base. CD44v6, the epitope which is most commonly associated with tumour progression and metastasis, was not only expressed by many benign colonic tumours, but was expressed as frequently in normal basal crypt epithelium as in malignant colonic tumour cells, and surprisingly, was even absent from some metastatic colorectal tumours. Expression of none of the CD44 variant epitopes was found to be positively correlated with tumour progression or with colorectal tumour metastasis to the liver, results which are inconsistent with a role for CD44 variants as indicators of colonic cancer progression. Images Figure 2 Figure 3 Figure 5 Figure 6 PMID:8695347

  15. Crystallographic characterization of the radixin FERM domain bound to the cytoplasmic tail of adhesion molecule CD44

    SciTech Connect

    Mori, Tomoyuki; Kitano, Ken; Terawaki, Shin-ichi; Maesaki, Ryoko; Hakoshima, Toshio

    2007-10-01

    The radixin FERM domain complexed with the CD44 cytoplasmic tail peptide has been crystallized. A diffraction data set from the complex was collected to 2.1 Å. CD44 is an important adhesion molecule that specifically binds hyaluronic acid and regulates cell–cell and cell–matrix interactions. Increasing evidence has indicated that CD44 is assembled in a regulated manner into the membrane–cytoskeletal junction, a process that is mediated by ERM (ezrin/radixin/moesin) proteins. Crystals of a complex between the radixin FERM domain and the C-terminal cytoplasmic region of CD44 have been obtained. The crystal of the radixin FERM domain bound to the CD44 cytoplasmic tail peptide belongs to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 62.70, b = 66.18, c = 86.22 Å, and contain one complex in the crystallographic asymmetric unit. An intensity data set was collected to a resolution of 2.1 Å.

  16. A novel mechanism of regulating breast cancer cell migration via palmitoylation-dependent alterations in the lipid raft affiliation of CD44

    PubMed Central

    2014-01-01

    Introduction Most breast cancer-related deaths result from metastasis, a process involving dynamic regulation of tumour cell adhesion and migration. The adhesion protein CD44, a key regulator of cell migration, is enriched in cholesterol-enriched membrane microdomains termed lipid rafts. We recently reported that raft affiliation of CD44 negatively regulates interactions with its migratory binding partner ezrin. Since raft affiliation is regulated by post-translational modifications including palmitoylation, we sought to establish the contribution of CD44 palmitoylation and lipid raft affiliation to cell migration. Methods Recovery of CD44 and its binding partners from raft versus non-raft membrane microdomains was profiled in non-migrating and migrating breast cancer cell lines. Site-directed mutagenesis was used to introduce single or double point mutations into both CD44 palmitoylation sites (Cys286 and Cys295), whereupon the implications for lipid raft recovery, phenotype, ezrin co-precipitation and migratory behaviour was assessed. Finally CD44 palmitoylation status and lipid raft affiliation was assessed in primary cultures from a small panel of breast cancer patients. Results CD44 raft affiliation was increased during migration of non-invasive breast cell lines, but decreased during migration of highly-invasive breast cells. The latter was paralleled by increased CD44 recovery in non-raft fractions, and exclusive non-raft recovery of its binding partners. Point mutation of CD44 palmitoylation sites reduced CD44 raft affiliation in invasive MDA-MB-231 cells, increased CD44-ezrin co-precipitation and accordingly enhanced cell migration. Expression of palmitoylation-impaired (raft-excluded) CD44 mutants in non-invasive MCF-10a cells was sufficient to reversibly induce the phenotypic appearance of epithelial-to-mesenchymal transition and to increase cell motility. Interestingly, cell migration was associated with temporal reductions in CD44 palmitoylation in

  17. CD44 regulates Wnt signaling at the level of LRP6

    PubMed Central

    Orian-Rousseau, Véronique; Schmitt, Mark

    2015-01-01

    CD44 was recently identified as a positive feedback regulator of Wnt/β-catenin signaling. This regulation occurs at the level of low-density lipoprotein receptor-related protein 6 phosphorylation and membrane targeting. These findings broaden our understanding of the Wnt pathway activation process and open new perspectives for anti-CD44 therapies in diseases associated with Wnt induction, including colorectal cancer. PMID:27308483

  18. Kaempferol regulates OPN-CD44 pathway to inhibit the atherogenesis of apolipoprotein E deficient mice

    SciTech Connect

    Xiao, Hong-Bo; Lu, Xiang-Yang; Sun, Zhi-Liang; Zhang, Heng-Bo

    2011-12-15

    Recent studies show that osteopontin (OPN) and its receptor cluster of differentiation 44 (CD44) are two pro-inflammatory cytokines contributing to the development of atherosclerosis. The objective of this study was to explore the inhibitory effect of kaempferol, a naturally occurring flavonoid compound, on atherogenesis and the mechanisms involved. The experiments were performed in aorta and plasma from C57BL/6J control and apolipoprotein E-deficient (ApoE{sup -/-}) mice treated or not with kaempferol (50 or 100 mg/kg, intragastrically) for 4 weeks. Kaempferol treatment decreased atherosclerotic lesion area, improved endothelium-dependent vasorelaxation, and increased the maximal relaxation value concomitantly with decrease in the half-maximum effective concentration, plasma OPN level, aortic OPN expression, and aortic CD44 expression in ApoE{sup -/-} mice. In addition, treatment with kaempferol also significantly decreased reactive oxygen species production in mice aorta. The present results suggest that kaempferol regulates OPN-CD44 pathway to inhibit the atherogenesis of ApoE{sup -/-} mice. -- Graphical abstract: Kaempferol regulates OPN-CD44 pathway to inhibit the atherogenesis of ApoE{sup -/-} mice. Highlights: Black-Right-Pointing-Pointer OPN-CD44 pathway plays a critical role in the development of atherosclerosis. Black-Right-Pointing-Pointer We examine lesion area, OPN and CD44 changes after kaempferol treatment. Black-Right-Pointing-Pointer Kaempferol treatment decreased atherosclerotic lesion area in ApoE{sup -/-} mice. Black-Right-Pointing-Pointer Kaempferol treatment decreased aortic OPN and CD44 expressions in ApoE{sup -/-} mice. Black-Right-Pointing-Pointer Kaempferol regulates OPN-CD44 pathway to inhibit the atherogenesis.

  19. Role of EGR1 in regulation of stimulus-dependent CD44 transcription in B lymphocytes.

    PubMed Central

    Maltzman, J S; Carman, J A; Monroe, J G

    1996-01-01

    The immediate-early gene egr-1 encodes a transcription factor (EGR1) that links B-cell antigen receptor (BCR) signals to downstream activation events through the regulation of previously unidentified target genes. Here we identify the gene encoding the lymphocyte homing and migration protein CD44 as a target of EGR1 regulation in B cells. BCR-induced increases in CD44 mRNA expression and transcription levels are shown to occur in EGR1-expressing but not in nonexpressing subclones of the B-cell line WEHI-231. Kinetics of egr-1 transcription and the appearance of nuclear EGR1 protein precede CD44 induction and occur within 30 min after stimulation in the EGR1-expressing subclone. A single EGR1 binding motif is demonstrated at bp -301 of the human CD44 promoter. Cotransfection of a CD44 promoter-chloramphenicol acetyltransferase reporter construct with an egr-1 expression vector resulted in a 6.5- to 8.5-fold induction of transcriptional activity relative to an empty expression vector. The EGR1 binding motif was shown to be necessary for stimulus-induced expression of a CD44 promoter-chloramphenicol acetyltransferase reporter construct in nontransformed B lymphocytes and was required for transactivation by an EGR1 expression vector in a B-cell line. These studies identify EGR1 as an intermediary linking BCR-derived signals to the induction of CD44. The relevance of these molecular events to BCR signal transduction and antigen-stimulated B-cell-mediated immune responses is discussed. PMID:8628295

  20. Uncovering the dual role of RHAMM as an HA receptor and a regulator of CD44 expression in RHAMM-expressing mesenchymal progenitor cells

    PubMed Central

    Veiseh, Mandana; Leith, Sean J.; Tolg, Cornelia; Elhayek, Sallie S.; Bahrami, S. Bahram; Collis, Lisa; Hamilton, Sara; McCarthy, James B.; Bissell, Mina J.; Turley, Eva

    2015-01-01

    The interaction of hyaluronan (HA) with mesenchymal progenitor cells impacts trafficking and fate after tissue colonization during wound repair and these events contribute to diseases such as cancer. How this interaction occurs is poorly understood. Using 10T½ cells as a mesenchymal progenitor model and fluorescent (F-HA) or gold-labeled HA (G-HA) polymers, we studied the role of two HA receptors, RHAMM and CD44, in HA binding and uptake in non-adherent and adherent mesenchymal progenitor (10T½) cells to mimic aspects of cell trafficking and tissue colonization. We show that fluorescent labeled HA (F-HA) binding/uptake was high in non-adherent cells but dropped over time as cells became increasingly adherent. Non-adherent cells displayed both CD44 and RHAMM but only function-blocking anti-RHAMM and not anti-CD44 antibodies significantly reduced F-HA binding/uptake. Adherent cells, which also expressed CD44 and RHAMM, primarily utilized CD44 to bind to F-HA since anti-CD44 but not anti-RHAMM antibodies blocked F-HA uptake. RHAMM overexpression in adherent 10T½ cells led to increased F-HA uptake but this increased binding remained CD44 dependent. Further studies showed that RHAMM-transfection increased CD44 mRNA and protein expression while blocking RHAMM function reduced expression. Collectively, these results suggest that cellular microenvironments in which these receptors function as HA binding proteins differ significantly, and that RHAMM plays at least two roles in F-HA binding by acting as an HA receptor in non-attached cells and by regulating CD44 expression and display in attached cells. Our findings demonstrate adhesion-dependent mechanisms governing HA binding/ uptake that may impact development of new mesenchymal cell-based therapies. PMID:26528478

  1. Interleukin-1β-induced Reduction of CD44 Ser-325 Phosphorylation in Human Epidermal Keratinocytes Promotes CD44 Homomeric Complexes, Binding to Ezrin, and Extended, Monocyte-adhesive Hyaluronan Coats*

    PubMed Central

    Jokela, Tiina; Oikari, Sanna; Takabe, Piia; Rilla, Kirsi; Kärnä, Riikka; Tammi, Markku; Tammi, Raija

    2015-01-01

    The proinflammatory cytokine interleukin-1β (IL-1β) attracts leukocytes to sites of inflammation. One of the recruitment mechanisms involves the formation of extended, hyaluronan-rich pericellular coats on local fibroblasts, endothelial cells, and epithelial cells. In the present work, we studied how IL-1β turns on the monocyte adhesion of the hyaluronan coat on human keratinocytes. IL-1β did not influence hyaluronan synthesis or increase the amount of pericellular hyaluronan in these cells. Instead, we found that the increase in the hyaluronan-dependent monocyte binding was associated with the CD44 of the keratinocytes. Although IL-1β caused a small increase in the total amount of CD44, a more marked impact was the decrease of CD44 phosphorylation at serine 325. At the same time, IL-1β increased the association of CD44 with ezrin and complex formation of CD44 with itself. Treatment of keratinocyte cultures with KN93, an inhibitor of calmodulin kinase 2, known to phosphorylate Ser-325 in CD44, caused similar effects as IL-1β (i.e. homomerization of CD44 and its association with ezrin) and resulted in increased monocyte binding to keratinocytes in a hyaluronan-dependent way. Overexpression of wild type CD44 standard form, but not a corresponding CD44 mutant mimicking the Ser-325-phosphorylated form, was able to induce monocyte binding to keratinocytes. In conclusion, treatment of human keratinocytes with IL-1β changes the structure of their hyaluronan coat by influencing the amount, post-translational modification, and cytoskeletal association of CD44, thus enhancing monocyte retention on keratinocytes. PMID:25809479

  2. CD44 Plays a Critical Role in Regulating Diet-Induced Adipose Inflammation, Hepatic Steatosis, and Insulin Resistance

    PubMed Central

    Kang, Hong Soon; Liao, Grace; DeGraff, Laura M.; Gerrish, Kevin; Bortner, Carl D.; Garantziotis, Stavros; Jetten, Anton M.

    2013-01-01

    CD44 is a multifunctional membrane receptor implicated in the regulation of several biological processes, including inflammation. CD44 expression is elevated in liver and white adipose tissue (WAT) during obesity suggesting a possible regulatory role for CD44 in metabolic syndrome. To study this hypothesis, we examined the effect of the loss of CD44 expression on the development of various features of metabolic syndrome using CD44 null mice. Our study demonstrates that CD44-deficient mice (CD44KO) exhibit a significantly reduced susceptibility to the development of high fat-diet (HFD)-induced hepatic steatosis, WAT-associated inflammation, and insulin resistance. The decreased expression of genes involved in fatty acid synthesis and transport (Fasn and Cd36), de novo triglyceride synthesis (Mogat1), and triglyceride accumulation (Cidea, Cidec) appears in part responsible for the reduced hepatic lipid accumulation in CD44KO(HFD) mice. In addition, the expression of various inflammatory and cell matrix genes, including several chemokines and its receptors, osteopontin, and several matrix metalloproteinases and collagen genes was greatly diminished in CD44KO(HFD) liver consistent with reduced inflammation and fibrogenesis. In contrast, lipid accumulation was significantly increased in CD44KO(HFD) WAT, whereas inflammation as indicated by the reduced infiltration of macrophages and expression of macrophage marker genes, was significantly diminished in WAT of CD44KO(HFD) mice compared to WT(HFD) mice. CD44KO(HFD) mice remained considerably more insulin sensitive and glucose tolerant than WT(HFD) mice and exhibited lower blood insulin levels. Our study indicates that CD44 plays a critical role in regulating several aspects of metabolic syndrome and may provide a new therapeutic target in the management of insulin resistance. PMID:23505504

  3. Isolation of All CD44 Transcripts in Human Epidermis and Regulation of Their Expression by Various Agents

    PubMed Central

    Teye, Kwesi; Numata, Sanae; Ishii, Norito; Krol, Rafal P.; Tsuchisaka, Atsunari; Hamada, Takahiro; Koga, Hiroshi; Karashima, Tadashi; Ohata, Chika; Tsuruta, Daisuke; Saya, Hideyuki; Haftek, Marek; Hashimoto, Takashi

    2016-01-01

    CD44, a cell surface proteoglycan, is involved in many biological events. CD44 transcripts undergo complex alternative splicing, resulting in many functionally distinct isoforms. To date, however, the nature of these isoforms in human epidermis has not been adequately determined. In this study, we isolated all CD44 transcripts from normal human epidermis, and studied how their expressions are regulated. By RT-PCR, we found that a number of different CD44 transcripts were expressed in human epidermis, and we obtained all these transcripts from DNA bands in agarose and acrylamide gels by cloning. Detailed sequence analysis revealed 18 CD44 transcripts, 3 of which were novel. Next, we examined effects of 10 different agents on the expression of CD44 transcripts in cultured human keratinocytes, and found that several agents, particularly epidermal growth factor, hydrogen peroxide, phorbol 12-myristate 13-acetate, retinoic acid, calcium and fetal calf serum differently regulated their expressions in various patterns. Furthermore, normal and malignant keratinocytes were found to produce different CD44 transcripts upon serum stimulation and subsequent starvation, suggesting that specific CD44 isoforms are involved in tumorigenesis via different CD44-mediated biological pathways. PMID:27505250

  4. CD44 Binding to Hyaluronic Acid Is Redox Regulated by a Labile Disulfide Bond in the Hyaluronic Acid Binding Site

    PubMed Central

    Kellett-Clarke, Helena; Stegmann, Monika; Barclay, A. Neil; Metcalfe, Clive

    2015-01-01

    CD44 is the primary leukocyte cell surface receptor for hyaluronic acid (HA), a component of the extracellular matrix. Enzymatic post translational cleavage of labile disulfide bonds is a mechanism by which proteins are structurally regulated by imparting an allosteric change and altering activity. We have identified one such disulfide bond in CD44 formed by Cys77 and Cys97 that stabilises the HA binding groove. This bond is labile on the surface of leukocytes treated with chemical and enzymatic reducing agents. Analysis of CD44 crystal structures reveal the disulfide bond to be solvent accessible and in the–LH hook configuration characteristic of labile disulfide bonds. Kinetic trapping and binding experiments on CD44-Fc chimeric proteins show the bond is preferentially reduced over the other disulfide bonds in CD44 and reduction inhibits the CD44-HA interaction. Furthermore cells transfected with CD44 no longer adhere to HA coated surfaces after pre-treatment with reducing agents. The implications of CD44 redox regulation are discussed in the context of immune function, disease and therapeutic strategies. PMID:26379032

  5. Trans-acting factors regulate the expression of CD44 splice variants.

    PubMed Central

    Konig, H; Moll, J; Ponta, H; Herrlich, P

    1996-01-01

    Variant isoforms of the cell surface glycoprotein CD44 (CD44v) are expressed during development, in selected adult tissues and in certain metastatic tumor cells. CD44v differ from the standard isoform (CD44s) by up to ten additional exon sequences included by alternative splicing. By cell fusion experiments, we have obtained evidence for the existence of cell-type specific trans-acting factors recruiting CD44 variant exon sequences. Stable cell hybrids of CD44s and CD44v expressing cells indicated a dominant mechanism for variant-exon inclusion. In transient interspecies heterokaryons of human keratinocytes and rat fibroblasts, the ability of the keratinocytes to include all variant exon sequences in CD44 was conferred completely on the rat fibroblast nucleus. Fusions of cells with complex CD44 splice patterns do not permit interpretation of splice control by the relative abundance of a single trans-acting factor, but rather by (a) positively acting factor(s) recruiting variant exon sequences in the 3' to 5' direction and additional factors selecting individual exons. Since the pancreatic carcinoma cell line BSp73ASML (in contrast to the cervix carcinoma cell lines SiHa and ME180) could not transfer its specific splice pattern in cell fusions, we conclude that in some tumors, splicing is also controlled by mutation of cis-acting recognition sites. Images PMID:8670907

  6. CD44 alternative splicing in gastric cancer cells is regulated by culture dimensionality and matrix stiffness.

    PubMed

    Branco da Cunha, Cristiana; Klumpers, Darinka D; Koshy, Sandeep T; Weaver, James C; Chaudhuri, Ovijit; Seruca, Raquel; Carneiro, Fátima; Granja, Pedro L; Mooney, David J

    2016-08-01

    Two-dimensional (2D) cultures often fail to mimic key architectural and physical features of the tumor microenvironment. Advances in biomaterial engineering allow the design of three-dimensional (3D) cultures within hydrogels that mimic important tumor-like features, unraveling cancer cell behaviors that would not have been observed in traditional 2D plastic surfaces. This study determined how 3D cultures impact CD44 alternative splicing in gastric cancer (GC) cells. In 3D cultures, GC cells lost expression of the standard CD44 isoform (CD44s), while gaining CD44 variant 6 (CD44v6) expression. This splicing switch was reversible, accelerated by nutrient shortage and delayed at lower initial cell densities, suggesting an environmental stress-induced response. It was further shown to be dependent on the hydrogel matrix mechanical properties and accompanied by the upregulation of genes involved in epithelial-mesenchymal transition (EMT), metabolism and angiogenesis. The 3D cultures reported here revealed the same CD44 alternative splicing pattern previously observed in human premalignant and malignant gastric lesions. These findings indicate that fundamental features of 3D cultures - such as soluble factors diffusion and mechanical cues - influence CD44 expression in GC cells. Moreover, this study provides a new model system to study CD44 dysfunction, whose role in cancer has been in the spotlight for decades. PMID:27187279

  7. Interactions between Hyaluronan and Its Receptors (CD44, RHAMM) Regulate the Activities of Inflammation and Cancer

    PubMed Central

    Misra, Suniti; Hascall, Vincent C.; Markwald, Roger R.; Ghatak, Shibnath

    2015-01-01

    The glycosaminoglycan hyaluronan (HA), a major component of extracellular matrices, and cell surface receptors of HA have been proposed to have pivotal roles in cell proliferation, migration, and invasion, which are necessary for inflammation and cancer progression. CD44 and receptor for HA-mediated motility (RHAMM) are the two main HA-receptors whose biological functions in human and murine inflammations and tumor cells have been investigated comprehensively. HA was initially considered to be only an inert component of connective tissues, but is now known as a “dynamic” molecule with a constant turnover in many tissues through rapid metabolism that involves HA molecules of various sizes: high molecular weight HA (HMW HA), low molecular weight HA, and oligosaccharides. The intracellular signaling pathways initiated by HA interactions with CD44 and RHAMM that lead to inflammatory and tumorigenic responses are complex. Interestingly, these molecules have dual functions in inflammations and tumorigenesis. For example, the presence of CD44 is involved in initiation of arthritis, while the absence of CD44 by genetic deletion in an arthritis mouse model increases rather than decreases disease severity. Similar dual functions of CD44 exist in initiation and progression of cancer. RHAMM overexpression is most commonly linked to cancer progression, whereas loss of RHAMM is associated with malignant peripheral nerve sheath tumor growth. HA may similarly perform dual functions. An abundance of HMW HA can promote malignant cell proliferation and development of cancer, whereas antagonists to HA-CD44 signaling inhibit tumor cell growth in vitro and in vivo by interfering with HMW HA-CD44 interaction. This review describes the roles of HA interactions with CD44 and RHAMM in inflammatory responses and tumor development/progression, and how therapeutic strategies that block these key inflammatory/tumorigenic processes may be developed in rodent and human diseases. PMID:25999946

  8. ERK1/2 regulation of CD44 modulates oral cancer aggressiveness

    PubMed Central

    Judd, Nancy P.; Winkler, Ashley E.; Murillo-Sauca, Oihana; Brotman, Joshua J.; Law, Jonathan H.; Lewis, James S.; Dunn, Gavin P.; Bui, Jack D.; Sunwoo, John B.; Uppaluri, Ravindra

    2011-01-01

    Carcinogen-induced oral cavity squamous cell carcinoma (OSCC) incurs significant morbidity and mortality and constitutes a global health challenge. To gain further insight into this disease, we generated cell line models from DMBA-induced murine primary OSCC capable of tumor formation upon transplantation into immunocompetent wild-type mice. While several lines grew rapidly and were capable of metastasis, some grew slowly and did not metastasize. Aggressively growing lines displayed ERK1/2 activation, which stimulated expression of CD44, a marker associated with EMT and putative cancer stem cells. MEK inhibition upstream of ERK1/2 decreased CD44 expression and promoter activity and reduced cell migration and invasion. Conversely, MEK1 activation enhanced CD44 expression and promoter activity, whereas CD44 attenuation reduced in vitro migration and in vivo tumor formation. Extending these findings to freshly resected human OSCC, we confirmed a strict relationship between ERK1/2 phosphorylation and CD44 expression. In summary, our findings identify CD44 as a critical target of ERK1/2 in promoting tumor aggressiveness and offer a preclinical proof of concept to target this pathway as a strategy to treat head and neck cancer. PMID:22086849

  9. Interactions between CD44 and Hyaluronan in Leukocyte Trafficking

    PubMed Central

    McDonald, Braedon; Kubes, Paul

    2015-01-01

    Recruitment of leukocytes from the bloodstream to inflamed tissues requires a carefully regulated cascade of binding interactions between adhesion molecules on leukocytes and endothelial cells. Adhesive interactions between CD44 and hyaluronan (HA) have been implicated in the regulation of immune cell trafficking within various tissues. In this review, the biology of CD44–HA interactions in cell trafficking is summarized, with special attention to neutrophil recruitment within the liver microcirculation. We describe the molecular mechanisms that regulate adhesion between neutrophil CD44 and endothelial HA, including recent evidence implicating serum-derived hyaluronan-associated protein as an important co-factor in the binding of HA to CD44 under flow conditions. CD44–HA-mediated neutrophil recruitment has been shown to contribute to innate immune responses to invading microbes, as well as to the pathogenesis of many inflammatory diseases, including various liver pathologies. As a result, blockade of neutrophil recruitment by targeting CD44–HA interactions has proven beneficial as an anti-inflammatory treatment strategy in a number of animal models of inflammatory diseases. PMID:25741341

  10. Possible involvement of CD10 in the development of endometriosis due to its inhibitory effects on CD44-dependent cell adhesion.

    PubMed

    Iwase, Akira; Kotani, Tomomi; Goto, Maki; Kobayashi, Hiroharu; Takikawa, Sachiko; Nakahara, Tatsuo; Nakamura, Tomoko; Kondo, Mika; Bayasula; Nagatomo, Yoshinari; Kikkawa, Fumitaka

    2014-01-01

    A reduced response to progesterone in the eutopic endometrium with endometriosis and in endometriotic tissues is considered to be the underlying factor for endometriosis. CD10 is known to be expressed by endometrial and endometriotic stromal cells and may be induced by progestins, although the function of CD10 is not fully revealed in endometrial or endometriotic tissues. In the current study, the expression of CD10 was significantly increased by treatment of the cells with progesterone, 17β-estradiol, and dibutyryl cyclic adenosine monophosphate (cAMP) in the endometrial stromal cells. On the other hand, the expression of CD10 following treatment with progesterone, 17β-estradiol, and dibutyryl cAMP was not significantly increased in endometriotic stromal cells. The adhesion assay for endometrial and endometriotic stromal cells to hyaluronan using 5- or 6-(N-succinimidyloxycarbonyl)-fluorescein 3', 6'-diacetate-labeled cells demonstrated that the CD44-dependent adhesion of stromal cells was inhibited by CD10. As far as the induction of CD10 is concerned, the effect of progesterone was different between endometrial stromal cells and endometriotic stromal cells. CD10 might be involved in the development of endometriosis due to its influence on CD44-dependent cell adhesion. PMID:23653392

  11. Downregulation of CD44 reduces doxorubicin resistance of CD44+CD24− breast cancer cells

    PubMed Central

    Van Phuc, Pham; Nhan, Phan Lu Chinh; Nhung, Truong Hai; Tam, Nguyen Thanh; Hoang, Nguyen Minh; Tue, Vuong Gia; Thuy, Duong Thanh; Ngoc, Phan Kim

    2011-01-01

    Background Cells within breast cancer stem cell populations have been confirmed to have a CD44+CD24− phenotype. Strong expression of CD44 plays a critical role in numerous types of human cancers. CD44 is involved in cell differentiation, adhesion, and metastasis of cancer cells. Methods In this study, we reduced CD44 expression in CD44+CD24− breast cancer stem cells and investigated their sensitivity to an antitumor drug. The CD44+CD24− breast cancer stem cells were isolated from breast tumors; CD44 expression was downregulated with siRNAs followed by treatment with different concentrations of the antitumor drug. Results The proliferation of CD44 downregulated CD44+CD24− breast cancer stem cells was decreased after drug treatment. We noticed treated cells were more sensitive to doxorubicin, even at low doses, compared with the control groups. Conclusions It would appear that expression of CD44 is integral among the CD44+CD24− cell population. Reducing the expression level of CD44, combined with doxorubicin treatment, yields promising results for eradicating breast cancer stem cells in vitro. This study opens a new direction in treating breast cancer through gene therapy in conjunction with chemotherapy. PMID:21792314

  12. The Anti-Migratory Effects of FKBPL and Its Peptide Derivative, AD-01: Regulation of CD44 and the Cytoskeletal Pathway

    PubMed Central

    Yakkundi, Anita; McCallum, Lynn; O’Kane, Anthony; Dyer, Hayder; Worthington, Jenny; McKeen, Hayley D.; McClements, Lana; Elliott, Christopher; McCarthy, Helen O.; Hirst, David G.; Robson, Tracy

    2013-01-01

    FK506 binding protein-like (FKBPL) and its peptide derivatives exert potent anti-angiogenic activity in vitro and in vivo and control tumour growth in xenograft models, when administered exogenously. However, the role of endogenous FKBPL in angiogenesis is not well characterised. Here we investigated the molecular effects of the endogenous protein and its peptide derivative, AD-01, leading to their anti-migratory activity. Inhibition of secreted FKBPL using a blocking antibody or siRNA-mediated knockdown of FKBPL accelerated the migration of human microvascular endothelial cells (HMEC-1). Furthermore, MDA-MB-231 tumour cells stably overexpressing FKBPL inhibited tumour vascular development in vivo suggesting that FKBPL secreted from tumour cells could inhibit angiogenesis. Whilst FKBPL and AD-01 target CD44, the nature of this interaction is not known and here we have further interrogated this aspect. We have demonstrated that FKBPL and AD-01 bind to the CD44 receptor and inhibit tumour cell migration in a CD44 dependant manner; CD44 knockdown abrogated AD-01 binding as well as its anti-migratory activity. Interestingly, FKBPL overexpression and knockdown or treatment with AD-01, regulated CD44 expression, suggesting a co-regulatory pathway for these two proteins. Downstream of CD44, alterations in the actin cytoskeleton, indicated by intense cortical actin staining and a lack of cell spreading and communication were observed following treatment with AD-01, explaining the anti-migratory phenotype. Concomitantly, AD-01 inhibited Rac-1 activity, up-regulated RhoA and the actin binding proteins, profilin and vinculin. Thus the anti-angiogenic protein, FKBPL, and AD-01, offer a promising and alternative approach for targeting both CD44 positive tumours and vasculature networks. PMID:23457460

  13. MiR-199a inhibits the ability of proliferation and migration by regulating CD44-Ezrin signaling in cutaneous squamous cell carcinoma cells

    PubMed Central

    Wang, Shao-Hua; Zhou, Jian-Da; He, Quan-Yong; Yin, Zhao-Qi; Cao, Ke; Luo, Cheng-Qun

    2014-01-01

    Cutaneous squamous cell carcinoma (cSCC), the second most common form of human cancer, is an epithelial skin tumor, which can result in metastasis with lethal consequences accounting for about 20% of all skin cancer-related deaths. The metastasis is the main reason for cSCC-related deaths with an overall 5-year survival rate < 30% in cases that spread systemically. The role of miRNAs has been involved in SCC of different origins. Recent data have revealed that the expression of miRNA-199a was changed in many human cancers. In this study, we found that miR-199a was significantly decreased in cSCC tissues, which had an inverse relationship with CD44. MiR-199a specifically regulated the expression of CD44 at mRNA and protein levels, and the interaction between CD44 and Ezrin in cSCC cells. Moreover, the suppressive role of miR-199a in cell migration in cSCC cells was also associated with the activity of MMP2 and MMP9. Taken together, our data indicated that increased expression of endogenous mature miR-199a might prevent the growth and migration of human cSCC via decreasing the expression of CD44 and regulating the interaction between CD44 and Ezrin, which may provide a potentially important therapeutic target for human cSCC. PMID:25400809

  14. Expression and Function of CD44 in Epithelial Ovarian Carcinoma

    PubMed Central

    Sacks, Joelle D.; Barbolina, Maria V.

    2015-01-01

    CD44, a cell surface glycoprotein, has been increasingly implicated in the pathogenesis and progression of epithelial ovarian cancer, the deadliest gynecologic malignancy in women. Here, we review recent reports on the expression and function of CD44 in epithelial ovarian carcinoma. Further functional data for CD44 in peritoneal adhesion and metastatic progression and its association with stem cells is highlighted. Recent studies utilizing CD44 for therapeutic targeting are also discussed. PMID:26569327

  15. DNA Aptamers against Exon v10 of CD44 Inhibit Breast Cancer Cell Migration

    PubMed Central

    Iida, Joji; Clancy, Rebecca; Dorchak, Jesse; Somiari, Richard I.; Somiari, Stella; Cutler, Mary Lou; Mural, Richard J.; Shriver, Craig D.

    2014-01-01

    CD44 adhesion molecules are expressed in many breast cancer cells and have been demonstrated to play a key role in regulating malignant phenotypes such as growth, migration, and invasion. CD44 is an integral transmembrane protein encoded by a single 20-exon gene. The diversity of the biological functions of CD44 is the result of the various splicing variants of these exons. Previous studies suggest that exon v10 of CD44 plays a key role in promoting cancer invasion and metastasis, however, the molecular mechanisms are not clear. Given the fact that exon v10 is in the ectodomain of CD44, we hypothesized that CD44 forms a molecular complex with other cell surface molecules through exon v10 in order to promote migration of breast cancer cells. In order to test this hypothesis, we selected DNA aptamers that specifically bound to CD44 exon v10 using Systematic Evolution of Ligands by Exponential Enrichment (SELEX). We selected aptamers that inhibited migration of breast cancer cells. Co-immunoprecipitation studies demonstrated that EphA2 was co-precipitated with CD44. Pull-down studies demonstrated that recombinant CD44 exon v10 bound to EphA2 and more importantly aptamers that inhibited migration also prevented the binding of EphA2 to exon v10. These results suggest that CD44 forms a molecular complex with EphA2 on the breast cancer cell surface and this complex plays a key role in enhancing breast cancer migration. These results provide insight not only for characterizing mechanisms of breast cancer migration but also for developing target-specific therapy for breast cancers and possibly other cancer types expressing CD44 exon v10. PMID:24586375

  16. Isoproterenol regulates CD44 expression in gastric cancer cells through STAT3/MicroRNA373 cascade.

    PubMed

    Wei, Bo; Sun, Xiaoyan; Geng, Zhijun; Shi, Ming; Chen, Zhida; Chen, Lin; Wang, Yongan; Fu, Xiaobing

    2016-10-01

    Gastric cancer is a heterogeneous disease, and stem cells are thought to be the cell of origin contributed to this malignancy. However, studies with breast and intestinal cancer models show non-stem cancer cells can change their surface phenotype and convert into tumor-initiating cells induced by the signals emanating from surrounding tumor microenvironment. Here, we show that CD44 was expressed at different levels in gastric metastases compared with primary tumors, and also negatively correlated with the expression of miR-373. By using a panel of human gastric cancer cell lines and analysis of archived data from The Cancer Genomics Altas (TCGA) database, we verified the inverse correlation between CD44 and miR-373. Furthermore, the stress-associated hormone, isoproterenol, could increase the expression levels of "stem"-related proteins, such as CD44, Nanog, and Rex-1, and induce chemoresistance in gastric cancer cells. Transfection with miR-373, however, reversed not only the effect of isoproterenol on phenotypic conversion but also its effect on drug sensitivity. Isoproterenol triggered downstream target STAT3 mainly through β2-adrenergic receptors (β2-ARs). Activated STAT3 functioned as a miR-373 suppressor by binding to its promoter, which forms a positive feedback circuit to maintain CD44 activity and direct the phenotypic conversion from CD44(low) to CD44(hi) expression. Our data suggest an important role of β2-AR/STAT3/miR-373 signaling on the transformation of gastric cancer cells. This study also suggests a potential therapeutic or preventive treatment for gastric cancer patients who are especially prone to psychosocial stress. PMID:27512943

  17. The Role of CD44 in the Pathophysiology of Chronic Lymphocytic Leukemia

    PubMed Central

    Gutjahr, Julia Christine; Greil, Richard; Hartmann, Tanja Nicole

    2015-01-01

    CD44 interactions with hyaluronan (HA) play a key role in various malignancies, supporting tumor cell migration, adhesion, and survival. In contrast to solid tumors, the expression of CD44 standard and variant forms and their functional interplay with HA is less understood in hematological malignancies. Chronic lymphocytic leukemia (CLL) is a highly abundant B-cell malignancy with a well coordinated balance between cell cycle-arrest and proliferation of tumor subpopulations. The long-term survival and proliferation of CLL cells requires their dynamic interactions with stromal and immune cells in lymphoid organs. Interactions of HA with CD44 and HA-mediated motility receptor (RHAMM) contribute to CLL cell localization, and hence CLL pathophysiology, by shaping homing, interstitial migration, and adhesion of the tumor cells. CD44 can complex with key prognostic factors of CLL, particularly CD38 and CD49d, bridging the gap between prognosis and cellular function. Here, we review the current evidence for the individual and associated contributions of CD44 to CLL pathophysiology, the dynamic functional regulation of CD44 upon CLL cell activation, and possible therapeutic strategies targeting CD44 in CLL. PMID:25941526

  18. A role for CD44 in T cell development and function during direct competition between CD44+ and CD44- cells.

    PubMed

    Graham, Victoria A; Marzo, Amanda L; Tough, David F

    2007-04-01

    The role of CD44 in T cell biology remains incompletely understood. Although studies using anti-CD44 antibodies have implicated this cell adhesion molecule in a variety of important T cell processes, few T cell defects have been reported in CD44-deficient mice. We have assessed the requirement for CD44 in T cell development and mature T cell function by analyzing mice in which CD44(-/-) and WT cells were produced simultaneously. In mixed (CD44(-/-) + CD44(+/+)) bone marrow chimeras, production of CD44(-/-) T cells was shown to be reduced compared to WT cells due to inefficient intrathymic development. In addition, mature CD44(-/-) CD8(+) T cells generated a substantially lower response than WT T cells after infection of mice with lymphocytic choriomeningitis virus, with the reduction in response apparent in both lymphoid and non-lymphoid tissues. Overall, these results demonstrate a poor capacity of CD44(-/-) T lineage cells to compete with WT cells at multiple levels, implicating CD44 in normal T cell function. PMID:17330818

  19. The metastasis suppressor, NDRG1, inhibits “stemness” of colorectal cancer via down-regulation of nuclear β-catenin and CD44

    PubMed Central

    Wangpu, Xiongzhi; Yang, Xiao; Zhao, Jingkun; Lu, Jiaoyang; Guan, Shaopei; Lu, Jun; Kovacevic, Zaklina; Liu, Wensheng; Mi, Lan; Jin, Runsen; Sun, Jing; Yue, Fei; Ma, Junjun; Lu, Aiguo; Richardson, Des R.; Wang, Lishun; Zheng, Minhua

    2015-01-01

    N-myc downstream-regulated gene 1 (NDRG1), has been identified as an important metastasis suppressor for colorectal cancer (CRC). In this study, we investigated: (1) the effects of NDRG1 on CRC stemness and tumorigenesis; (2) the molecular mechanisms involved; and (3) the relationship between NDRG1 expression and colorectal cancer prognosis. Our investigation demonstrated that CRC cells with silenced NDRG1 showed more tumorigenic ability and stem cell-like properties, such as: colony and sphere formation, chemoresistance, cell invasion, high expression of CD44, and tumorigenicity in vivo. Moreover, NDRG1 silencing reduced β-catenin expression on the cell membrane, while increasing its nuclear expression. The anti-tumor activity of NDRG1 was demonstrated to be mediated by preventing β-catenin nuclear translocation, as silencing of this latter molecule could reverse the effects of silencing NDRG1 expression. NDRG1 expression was also demonstrated to be negatively correlated to CRC prognosis. In addition, there was a negative correlation between NDRG1 and nuclear β-catenin and also NDRG1 and CD44 expression in clinical CRC specimens. Taken together, our investigation demonstrates that the anti-metastatic activity of NDRG1 in CRC occurs through the down-regulation of nuclear β-catenin and suggests that NDRG1 is a significant therapeutic target. PMID:26418878

  20. Twist2 promotes kidney cancer cell proliferation and invasion by regulating ITGA6 and CD44 expression in the ECM-receptor interaction pathway

    PubMed Central

    Zhang, Hao-jie; Tao, Jing; Sheng, Lu; Hu, Xin; Rong, Rui-ming; Xu, Ming; Zhu, Tong-yu

    2016-01-01

    Twist2 is a member of the basic helix-loop-helix (bHLH) family and plays a critical role in tumorigenesis. Growing evidence has proven that Twist2 is involved in tumor progression; however, the role of Twist2 in human kidney cancer and its underlying mechanisms remain unclear. Real-time polymerase chain reaction and Western blot analysis were used to detect the expression of Twist2 in kidney cancer cells and tissues. Cell proliferation, cell cycle, apoptosis, migration, and invasion assay were analyzed using the Cell Count Kit-8, flow cytometry, wound healing, and Transwell analysis, respectively. In this study, we showed that Twist2 was upregulated in human kidney cancer tissues compared with normal kidney tissues. Twist2 promoted cell proliferation, inhibited cell apoptosis, and augmented cell migration and invasion in human kidney-cancer-derived cells in vitro. Twist2 also promoted tumor growth in vivo. Moreover, we found that the knockdown of Twist2 decreased the levels of ITGA6 and CD44 expression. This result indicates that Twist2 may promote migration and invasion of kidney cancer cells by regulating ITGA6 and CD44 expression. Therefore, our data demonstrated that Twist2 is involved in kidney cancer progression. The identification of the role of Twist2 in the migration and invasion of kidney cancer provides a potential appropriate treatment for human kidney cancer. PMID:27099513

  1. CD44 enhances tumor aggressiveness by promoting tumor cell plasticity.

    PubMed

    Paulis, Yvette W J; Huijbers, Elisabeth J M; van der Schaft, Daisy W J; Soetekouw, Patricia M M B; Pauwels, Patrick; Tjan-Heijnen, Vivianne C G; Griffioen, Arjan W

    2015-08-14

    Aggressive tumor cells can obtain the ability to transdifferentiate into cells with endothelial features and thus form vasculogenic networks. This phenomenon, called vasculogenic mimicry (VM), is associated with increased tumor malignancy and poor clinical outcome. To identify novel key molecules implicated in the process of vasculogenic mimicry, microarray analysis was performed to compare gene expression profiles of aggressive (VM+) and non-aggressive (VM-) cells derived from Ewing sarcoma and breast carcinoma. We identified the CD44/c-Met signaling cascade as heavily relevant for vasculogenic mimicry. CD44 was at the center of this cascade, and highly overexpressed in aggressive tumors. Both CD44 standard isoform and its splice variant CD44v6 were linked to increased aggressiveness in VM. Since VM is most abundant in Ewing sarcoma tumors functional analyses were performed in EW7 cells. Overexpression of CD44 allowed enhanced adhesion to its extracellular matrix ligand hyaluronic acid. CD44 expression also facilitated the formation of vasculogenic structures in vitro, as CD44 knockdown experiments repressed migration and vascular network formation. From these results and the observation that CD44 expression is associated with vasculogenic structures and blood lakes in human Ewing sarcoma tissues, we conclude that CD44 increases aggressiveness in tumors through the process of vasculogenic mimicry. PMID:26189059

  2. Twist2 promotes kidney cancer cell proliferation and invasion via regulating ITGA6 and CD44 expression in the ECM-Receptor-Interaction pathway.

    PubMed

    Zhang, Hao-Jie; Tao, Jing; Sheng, Lu; Hu, Xin; Rong, Rui-Ming; Xu, Ming; Zhu, Tong-Yu

    2016-07-01

    Twist2 is a member of the basic helix-loop-helix (bHLH) family and plays a critical role in tumorigenesis. Growing evidence proves that Twist2 involves in tumor progression; however, the role of Twist2 in human kidney cancer and its underlying mechanisms remain unclear. RT-PCR and Western blot analysis were used to detect the expression of Twist2 in kidney cancer cells and tissues. Cell proliferation, cell cycle, apoptosis, migration and invasion assay was measured by the Cell Count Kit-8 (CCK8), flow cytometry, wound healing and transwell analysis, respectively. Gene set enrichment analysis (GSEA) was used to identify correlation of Twist2 with ECM-Receptor-Interaction pathway. In this report, we show that Twist2 up-regulated in human kidney cancer tissues compared with normal kidney tissues. Twist2 promotes cell proliferation, inhibits cell apoptosis, augments cell migration and invasion in human kidney cancer-derived cell in vitro, and promotes tumor growth in vivo. Moreover, we found that knockdown of Twist2 decreased the levels of ITGA6 and CD44 which contribute to cell migration and invasion correlated with ECM-Receptor-Interaction pathway. This result indicates Twist2 may promote migration and invasion of kidney cancer cells by regulating ITGA6 and CD44 expression. Therefore, our data demonstrated that Twist2 involves in kidney cancer progression. The identification of the role Twist2 on the migration and invasion of kidney cancer provides a potential appropriate treatment after radical nephrectomy to get a better prognosis that reducing recurrence. PMID:27261625

  3. Expression of CD44 variants in human inflammatory synovitis

    SciTech Connect

    Hale, L.P.; Haynes, B.F.; McCachren, S.

    1995-11-01

    The cell surface hyaluronate receptor CD44 has previously been shown to have immunomodulatory activity and to be upregulated in inflammatory synovitis. Since these findings were reported, the genomic structure of CD44 has been delineated, and multiple splice variants have been described. Therefore, we determined which CD44 variant exons are present during inflammatory synovitis by a combination of Northern blot analysis and reverse transcription followed by polymerase chain reaction amplification of synovial RNA. Immunohistochemical staining was used to define the sites of expression of individual v6 and v9 exons in synovial tissue. The standard (S) or hematopoietic isoform, CD44S, was the predominant form of CD44 expressed in synovium and was expressed by most cell types. Other isoforms, containing alternatively spliced exons in the proximal extracellular domain, were found by RT-PCR, but at lower levels than CD44S. The second most prevalent form was CD44E, which has an insertion of three exons (v8-v10) in the proximal extracellular domain. Immunohistochemical studies showed that reactivity with v9-specific antibodies was primarily in macrophages, particularly those in the synovial lining layer. CD44 exon v6, previously reported to be important in immune activation and in epithelial tumor metastasis, was also expressed in synovial lining cells and in occasional synovial interstitial cells. The presence of CD44 variants containing v9 in rheumatoid synovial macrophages may be important in the adhesion and activation of mononuclear phagocytes in the synovium and, thus, may be a target for novel antiinflammatory therapies in the future. The role of CD44 isoforms in cellular adhesion, immune activation, and joint erosion in inflammatory synovitis deserves further study. 7 figs., 2 tabs., 56 refs.

  4. Redox Regulation of Stem-like Cells Though the CD44v-xCT Axis in Colorectal Cancer: Mechanisms and Therapeutic Implications

    PubMed Central

    Ju, Huai-Qiang; Lu, Yun-Xin; Chen, Dong-Liang; Tian, Tian; Mo, Hai-Yu; Wei, Xiao-Li; Liao, Jian-Wei; Wang, Feng; Zeng, Zhao-Lei; Pelicano, Helene; Aguilar, Mitzi; Jia, Wei-Hua; Xu, Rui-Hua

    2016-01-01

    Colorectal cancer (CRC) is a common neoplastic disease and a frequent cause of death. Drug resistance is a major challenge to CRC treatment and stem-like side-population (SP) cells may play a key role in this resistance. Although it has been recognized that cancer stem cells may be affected by redox status, the underlying mechanisms for this effect and the roles of celllular redox adaptation and antioxidant capacity in CRC remain elusive. Our study shows that CRC SP cells are highly dependent on cellular GSH to maintain ROS levels below those of non-SP cells. Exposing CRC cells to H2O2 produced a significant decrease in the percentage of SP cells, which was rescued by adding N-acetylcysteine. Mechanistically, CD44v interacts with and stabilizes xCT and thereby promotes the uptake of cysteine for GSH synthesis and stimulates SP cell enrichment. Additionally, miR-1297 levels were inversely correlated with the expression of xCT; thus, reduced miR-1297 contributes to SP cell enrichment in CRC tumors, which results in tumor aggressiveness and poor clinical outcomes. Importantly, redox modification by PEITC significantly reduces CRC SP cells in vitro and impairs tumors growth in vivo. The combination of 5FU and PEITC led to synergistic cytotoxic effects against CRC cells in vitro and in vivo. Taken together, our data suggest that a GSH-mediated reduction in cellular ROS levels is an essential regulator of CRC SP cells mediated by the CD44v-xCT axis, and disrupting the redox status may eliminate the chemotherapy-resistant CRC SP cells with potentially significant benefits for cancer treatment. PMID:27279909

  5. The normal structure and function of CD44 and its role in neoplasia.

    PubMed Central

    Sneath, R J; Mangham, D C

    1998-01-01

    CD44 is a transmembrane glycoprotein, the variant isoforms of which are coded for by alternative splicing, with the most prolific isoform being CD44 standard. CD44 is found in a wide variety of tissues including the central nervous system, lung, epidermis, liver, and pancreas, whereas variant isoforms of CD44 (CD44v) appear to have a much more restricted distribution. Variants of CD44 are expressed in tissues during development, including embryonic epithelia. Known functions of CD44 are cellular adhesion (aggregation and migration), hyaluronate degradation, lymphocyte activation, lymph node homing, myelopoiesis and lymphopoiesis, angiogenesis, and release of cytokines. The functions of CD44 are principally dependant on cellular adhesion in one setting or another. The role of CD44 in neoplasia is less well defined, although metastatic potential can be conferred on non-metastasising cell lines by transfection with a variant of CD44 and high levels of CD44 are associated with several types of malignant tumours. The physiological functions of CD44 indicate that the molecule could be involved in the metastatic spread of tumours. Many studies have investigated the pattern of CD44 distribution in tumours and some observations suggest that certain cells do not use CD44 in tumorigenesis or in the production of metastases. However, the data are extremely conflicting, and further studies are needed to establish the prognostic value of CD44 and its variant isoforms. The precise function of CD44 in the metastatic process and the degree of involvement in human malignancies has yet to be established fully. PMID:9893744

  6. Modulation of CD44 Activity by A6-Peptide

    PubMed Central

    Finlayson, Malcolm

    2015-01-01

    Hyaluronan (HA) is a non-sulfated glycosaminoglycan distributed throughout the extracellular matrix that plays a major role in cell adhesion, migration, and proliferation. CD44, a multifunctional cell surface glycoprotein, is a receptor for HA. In addition, CD44 is known to interact with other receptors and ligands, and to mediate a number of cellular functions as well as disease progression. Studies have shown that binding of HA to CD44 in cancer cells activates survival pathways resulting in cancer cell survival. This effect can be blocked by anti-CD44 monoclonal antibodies. A6 is a capped, eight l-amino acid peptide (Ac-KPSSPPEE-NH2) derived from the biologically active connecting peptide domain of the serine protease, human urokinase plasminogen activator (uPA). A6 neither binds to the uPA receptor (uPAR) nor interferes with uPA/uPAR binding. A6 binds to CD44 resulting in the inhibition of migration, invasion, and metastasis of tumor cells, and the modulation of CD44-mediated cell signaling. A6 has been shown to have no dose-limiting toxicity in animal studies. A6 has demonstrated efficacy and an excellent safety profile in Phase 1a, 1b, and 2 clinical trials. In animal models, A6 has also exhibited promising results for the treatment of diabetic retinopathy and wet age-related macular degeneration through the reduction of retinal vascular permeability and inhibition of choroidal neovascularization, respectively. Recently, A6 has been shown to be directly cytotoxic for B-lymphocytes obtained from patients with chronic lymphocytic leukemia expressing the kinase, ZAP-70. This review will discuss the activity of A6, A6 modulation of HA and CD44, and a novel strategy for therapeutic intervention in disease. PMID:25870596

  7. Simvastatin inhibits CD44 fragmentation in chondrocytes.

    PubMed

    Terabe, Kenya; Takahashi, Nobunori; Takemoto, Toki; Knudson, Warren; Ishiguro, Naoki; Kojima, Toshihisa

    2016-08-15

    In human osteoarthritic chondrocytes, the hyaluronan receptor CD44 undergoes proteolytic cleavage at the cell surface. CD44 cleavage is thought to require transit of CD44 into cholesterol-rich lipid rafts. The purpose of this study was to investigate whether statins exert a protective effect on articular chondrocytes due to diminution of cholesterol. Three model systems of chondrocytes were examined including human HCS-2/8 chondrosarcoma cells, human osteoarthritic chondrocytes and normal bovine articular chondrocytes. Treatment with IL-1β + Oncostatin M resulted in a substantial increase in CD44 fragmentation in each of the three chondrocyte models. Pre-incubation with simvastatin prior to treatment with IL-1β + Oncostatin M decreased the level of CD44 fragmentation, decreased the proportion of CD44 that transits into the lipid raft fractions, decreased ADAM10 activity and diminished the interaction between CD44 and ADAM10. In HCS-2/8 cells and bovine articular chondrocytes, fragmentation of CD44 was blocked by the knockdown of ADAM10. Inhibition of CD44 fragmentation by simvastatin also resulted in improved retention of pericellular matrix. Addition of cholesterol and farnesyl-pyrophosphate reversed the protective effects of simvastatin. Thus, the addition of simvastatin exerts positive effects on chondrocytes including reduced CD44 fragmentation and enhanced the retention of pericellular matrix. PMID:27242325

  8. Soluble CD44 interacts with intermediate filament protein vimentin on endothelial cell surface.

    PubMed

    Päll, Taavi; Pink, Anne; Kasak, Lagle; Turkina, Marina; Anderson, Wally; Valkna, Andres; Kogerman, Priit

    2011-01-01

    CD44 is a cell surface glycoprotein that functions as hyaluronan receptor. Mouse and human serum contain substantial amounts of soluble CD44, generated either by shedding or alternative splicing. During inflammation and in cancer patients serum levels of soluble CD44 are significantly increased. Experimentally, soluble CD44 overexpression blocks cancer cell adhesion to HA. We have previously found that recombinant CD44 hyaluronan binding domain (CD44HABD) and its non-HA-binding mutant inhibited tumor xenograft growth, angiogenesis, and endothelial cell proliferation. These data suggested an additional target other than HA for CD44HABD. By using non-HA-binding CD44HABD Arg41Ala, Arg78Ser, and Tyr79Ser-triple mutant (CD443MUT) we have identified intermediate filament protein vimentin as a novel interaction partner of CD44. We found that vimentin is expressed on the cell surface of human umbilical vein endothelial cells (HUVEC). Endogenous CD44 and vimentin coprecipitate from HUVECs, and when overexpressed in vimentin-negative MCF-7 cells. By using deletion mutants, we found that CD44HABD and CD443MUT bind vimentin N-terminal head domain. CD443MUT binds vimentin in solution with a Kd in range of 12-37 nM, and immobilised vimentin with Kd of 74 nM. CD443MUT binds to HUVEC and recombinant vimentin displaces CD443MUT from its binding sites. CD44HABD and CD443MUT were internalized by wild-type endothelial cells, but not by lung endothelial cells isolated from vimentin knock-out mice. Together, these data suggest that vimentin provides a specific binding site for soluble CD44 on endothelial cells. PMID:22216242

  9. CD44, Hyaluronan, the Hematopoietic Stem Cell, and Leukemia-Initiating Cells

    PubMed Central

    Zöller, Margot

    2015-01-01

    CD44 is an adhesion molecule that varies in size due to glycosylation and insertion of so-called variant exon products. The CD44 standard isoform (CD44s) is highly expressed in many cells and most abundantly in cells of the hematopoietic system, whereas expression of CD44 variant isoforms (CD44v) is more restricted. CD44s and CD44v are known as stem cell markers, first described for hematopoietic stem cells and later on confirmed for cancer- and leukemia-initiating cells. Importantly, both abundantly expressed CD44s as well as CD44v actively contribute to the maintenance of stem cell features, like generating and embedding in a niche, homing into the niche, maintenance of quiescence, and relative apoptosis resistance. This is surprising, as CD44 is not a master stem cell gene. I here will discuss that the functional contribution of CD44 relies on its particular communication skills with neighboring molecules, adjacent cells and, last not least, the surrounding matrix. In fact, it is the interaction of the hyaluronan receptor CD44 with its prime ligand, which strongly assists stem cells to fulfill their special and demanding tasks. Recent fundamental progress in support of this “old” hypothesis, which may soon pave the way for most promising new therapeutics, is presented for both hematopoietic stem cell and leukemia-initiating cell. The contribution of CD44 to the generation of a stem cell niche, to homing of stem cells in their niche, to stem cell quiescence and apoptosis resistance will be in focus. PMID:26074915

  10. WNT5A Inhibits Metastasis and Alters Splicing of Cd44 in Breast Cancer Cells

    PubMed Central

    Jiang, Wen; Crossman, David K.; Mitchell, Elizabeth H.; Sohn, Philip; Crowley, Michael R.; Serra, Rosa

    2013-01-01

    Wnt5a is a non-canonical signaling Wnt. Low expression of WNT5A is correlated with poor prognosis in breast cancer patients. The highly invasive breast cancer cell lines, MDA-MB-231 and 4T1, express very low levels of WNT5A. To determine if enhanced expression of WNT5A would affect metastatic behavior, we generated WNT5A expressing cells from the 4T1 and MDA-MB-231 parental cell lines. WNT5A expressing cells demonstrated cobblestone morphology and reduced in vitro migration relative to controls. Cell growth was not altered. Metastasis to the lung via tail vein injection was reduced in the 4T1-WNT5A expressing cells relative to 4T1-vector controls. To determine the mechanism of WNT5A action on metastasis, we performed microarray and whole-transcriptome sequence analysis (RNA-seq) to compare gene expression in 4T1-WNT5A and 4T1-vector cells. Analysis indicated highly significant alterations in expression of genes associated with cellular movement. Down-regulation of a subset of these genes, Mmp13, Nos2, Il1a, Cxcl2, and Lamb3, in WNT5A expressing cells was verified by semi-quantitative RT-PCR. Significant differences in transcript splicing were also detected in cell movement associated genes including Cd44. Cd44 is an adhesion molecule with a complex genome structure. Variable exon usage is associated with metastatic phenotype. Alternative spicing of Cd44 in WNT5A expressing cells was confirmed using RT-PCR. We conclude that WNT5A inhibits metastasis through down-regulation of multiple cell movement pathways by regulating transcript levels and splicing of key genes like Cd44. PMID:23484019

  11. The Role of CD44 in Disease Pathophysiology and Targeted Treatment

    PubMed Central

    Jordan, Andre R.; Racine, Ronny R.; Hennig, Martin J. P.; Lokeshwar, Vinata B.

    2015-01-01

    The cell-surface glycoprotein CD44 is involved in a multitude of important physiological functions including cell proliferation, adhesion, migration, hematopoiesis, and lymphocyte activation. The diverse physiological activity of CD44 is manifested in the pathology of a number of diseases including cancer, arthritis, bacterial and viral infections, interstitial lung disease, vascular disease, and wound healing. This diversity in biological activity is conferred by both a variety of distinct CD44 isoforms generated through complex alternative splicing, posttranslational modifications (e.g., N- and O-glycosylation), interactions with a number of different ligands, and the abundance and spatial distribution of CD44 on the cell surface. The extracellular matrix glycosaminoglycan hyaluronic acid (HA) is the principle ligand of CD44. This review focuses both CD44-hyaluronan dependent and independent CD44 signaling and the role of CD44–HA interaction in various pathophysiologies. The review also discusses recent advances in novel treatment strategies that exploit the CD44–HA interaction either for direct targeting or for drug delivery. PMID:25954275

  12. CD44 is a macrophage binding site for Mycobacterium tuberculosis that mediates macrophage recruitment and protective immunity against tuberculosis

    PubMed Central

    Leemans, Jaklien C.; Florquin, Sandrine; Heikens, Mirjam; Pals, Steven T.; Neut, Ronald van der; van der Poll, Tom

    2003-01-01

    Cell migration and phagocytosis are both important for controlling Mycobacterium tuberculosis infection and are critically dependent on the reorganization of the cytoskeleton. Since CD44 is an adhesion molecule involved in inflammatory responses and is connected to the actin cytoskeleton, we investigated the role of CD44 in both these processes. Macrophage (Mφ) recruitment into M. tuberculosis–infected lungs and delayed-type hypersensitivity sites was impaired in CD44-deficient (CD44–/–) mice. In addition, the number of T lymphocytes and the concentration of the protective key cytokine IFN-γ were reduced in the lungs of infected CD44–/– mice. The production of IFN-γ by splenocytes of CD44–/– mice was profoundly increased upon antigen-specific stimulation. Flow cytometry analysis revealed that soluble CD44 can directly bind to virulent M. tuberculosis. Mycobacteria also interacted with Mφ-associated CD44, as reflected by reduced binding and internalization of bacilli by CD44–/– Mφs. This suggests that CD44 is a receptor on Mφs for binding of M. tuberculosis. CD44–/– mice displayed a decreased survival and an enhanced mycobacterial outgrowth in lungs and liver during pulmonary tuberculosis. In summary, we have identified CD44 as a new Mφ binding site for M. tuberculosis that mediates mycobacterial phagocytosis, Mφ recruitment, and protective immunity against pulmonary tuberculosis. PMID:12618522

  13. Molecular mechanism for the action of the anti-CD44 monoclonal antibody MEM-85.

    PubMed

    Škerlová, Jana; Král, Vlastimil; Kachala, Michael; Fábry, Milan; Bumba, Ladislav; Svergun, Dmitri I; Tošner, Zdeněk; Veverka, Václav; Řezáčová, Pavlína

    2015-08-01

    The hyaluronate receptor CD44 plays role in cell adhesion and migration and is involved in tumor metastasis. The extracellular domain of CD44 comprises the hyaluronate-binding domain (HABD) and the membrane-proximal stem region; the short intracellular portion interacts with adaptor proteins and triggers signaling pathways. Binding of hyaluronate to CD44 HABD induces an allosteric conformational change, which results in CD44 shedding. A poorly characterized epitope in human CD44 HABD is recognized by the murine monoclonal antibody MEM-85, which cross-blocks hyaluronate binding to CD44 and also induces CD44 shedding. MEM-85 is of therapeutic interest, as it inhibits growth of lung cancer cells in murine models. In this work, we employed a combination of biophysical methods to determine the MEM-85 binding epitope in CD44 HABD and to provide detailed insight into the mechanism of MEM-85 action. In particular, we constructed a single-chain variable fragment (scFv) of MEM-85 as a tool for detailed characterization of the CD44 HABD-antibody complex and identified residues within CD44 HABD involved in the interaction with scFv MEM-85 by NMR spectroscopy and mutational analysis. In addition, we built a rigid body model of the CD44 HABD-scFv MEM-85 complex using a low-resolution structure obtained by small-angle X-ray scattering. The MEM-85 epitope is situated in the C-terminal part of CD44 HABD, rather than the hyaluronate-binding groove, and the binding of MEM-85 induces a structural reorganization similar to that induced by hyaluronate. Therefore, the mechanism of MEM-85 cross-blocking of hyaluronate binding is likely of an allosteric, relay-like nature. PMID:26066970

  14. Intracellular Domain Fragment of CD44 Alters CD44 Function in Chondrocytes*

    PubMed Central

    Mellor, Liliana; Knudson, Cheryl B.; Hida, Daisuke; Askew, Emily B.; Knudson, Warren

    2013-01-01

    The hyaluronan receptor CD44 undergoes sequential proteolytic cleavage at the cell surface. The initial cleavage of the CD44 extracellular domain is followed by a second intramembranous cleavage of the residual CD44 fragment, liberating the C-terminal cytoplasmic tail of CD44. In this study conditions that promote CD44 cleavage resulted in a diminished capacity to assemble and retain pericellular matrices even though sufficient non-degraded full-length CD44 remained. Using stable and transient overexpression of the cytoplasmic domain of CD44, we determined that the intracellular domain interfered with anchoring of the full-length CD44 to the cytoskeleton and disrupted the ability of the cells to bind hyaluronan and assemble a pericellular matrix. Co-immunoprecipitation assays were used to determine whether the mechanism of this interference was due to competition with actin adaptor proteins. CD44 of control chondrocytes was found to interact and co-immunoprecipitate with both the 65- and 130-kDa isoforms of ankyrin-3. Moreover, this interaction with ankyrin-3 proteins was diminished in cells overexpressing the CD44 intracellular domain. Mutating the putative ankyrin binding site of the transiently transfected CD44 intracellular domain diminished the inhibitory effects of this protein on matrix retention. Although CD44 in other cells types has been shown to interact with members of the ezrin/radixin/moesin (ERM) family of adaptor proteins, only modest interactions between CD44 and moesin could be demonstrated in chondrocytes. The data suggest that release of the CD44 intracellular domain into the cytoplasm of cells such as chondrocytes exerts a competitive or dominant-negative effect on the function of full-length CD44. PMID:23884413

  15. Expression of hyaluronic acid and its receptors, CD44s and CD44v6, in normal, hyperplastic, and neoplastic endometrium.

    PubMed

    Afify, Alaa M; Craig, Sarah; Paulino, Augusto F G; Stern, Robert

    2005-12-01

    The interaction between epithelial tumor cells and their surrounding stroma is important in tumor progression and metastasis. This is accomplished through a number of transmembrane receptors that interact with stromal extracellular matrix molecules. One of these receptors, CD44, binds to extracellular matrix component hyaluronic acid (HA). The purpose of this study was to evaluate the significance of HA, CD44s, and CD44v6 in benign, hyperplastic, atypical, and malignant endometrial epithelia. Archival paraffin-embedded cell blocks from proliferative endometrium (n = 11), secretory endometrium (n = 12), simple hyperplasia (n = 13), complex hyperplasia without atypia (n = 9), complex hyperplasia with atypia (n = 17), and adenocarcinoma (n = 21) were stained for HA, CD44s, and CD44v6. HA was detected throughout the normal menstrual cycle but was more intense during the secretory phase. Only during the secretory phase was CD44s expressed in the stromal cells in 11 cases (92%), whereas CD44v6 was detected in glandular epithelium in 9 (75%). CD44s was expressed in the glandular epithelium in 2 (15%) cases of simple hyperplasia, 4 (44%) of complex hyperplasia without atypia, 14 (82%) of complex hyperplasia with atypia, and in 16 (76%) of adenocarcinoma. CD44v6 was expressed in the glandular epithelium in 1 (11%) case of complex hyperplasia without atypia, 17 (100%) cases of complex hyperplasia with atypia, and in 18 (86%) cases of adenocarcinoma, but in none of the cases of simple hyperplasia. The endometrial stromal cells expressed CD44v6 in 1 (8%) case of simple hyperplasia, 6 (67%) of complex hyperplasia without atypia, 8 (47%) of complex hyperplasia with atypia, and in 3 (14%) of adenocarcinoma. We concluded that in the normal menstrual cycle, the timing of peak staining of HA and CD44s in the stroma and the up-regulation of CD44v6 in secretory glands are coincident with the period in which the endometrium is most receptive to embryo implantation. HA is more abundant

  16. The expression of CD44v6 in colon: from normal to malignant.

    PubMed

    Afify, Alaa; Durbin-Johnson, Blythe; Virdi, Avnit; Jess, Heidi

    2016-02-01

    CD44v6, an integral transmembrane protein belonging to a family of adhesion molecule receptors, plays an important role in tumor growth, progression and metastasis. The purpose of this study was to evaluate the expression of CD44v6 in normal, hyperplastic, adenomatous, and malignant colonic epithelium and to determine its correlation with tumor pathologic stage and lymph node metastasis. We examined the immunohistochemical expression of CD44v6 in normal colonic tissue (n = 25), hyperplastic polyps (n = 45), tubular adenomas (n = 57), tubulovillous adenomas (n = 25), villous adenomas (n = 9), adenocarcinomas stage I (n = 26), adenocarcinomas stage III (n = 26), and lymph node metastasis (n = 26). The percentage of positive cells and the staining intensity were assessed and scored. Statistical analysis was performed using logistic regression and McNemar test. All normal colonic tissue and hyperplastic polyps showed CD44v6 staining confined to the base of the crypt. In tubular adenomas, the dysplastic surface adenomatous epithelium expressed CD44v6 in 49 (86%) cases. CD44v6 was expressed in the glandular areas of tubulovillous adenomas in 21 (84%) cases and in the villous portion in 18 (72%) cases. All villous adenomas expressed CD44v6. CD44v6 was expressed in 23 (88%) cases of stage I adenocarcinomas, in 24 (92%) cases of stage III adenocarcinomas, and in 9 (35%) cases of metastatic adenocarcinomas. We concluded that the gain of CD44v6 expression in premalignant and malignant colonic lesions suggests that CD44v6 may be functionally involved in the adenoma-to-carcinoma progression. CD44v6 did not correlate to tumor pathologic stage and is lost during the acquisition of migratory function by metastatic tumor cells. PMID:26621455

  17. Immunolocalization of the hyaluronan receptor CD44 in the reproductive tract of the mare.

    PubMed

    Rodriguez Hurtado, I; Stewart, A J; Wolfe, D F; Caldwell, F J; Harrie, M; Whitley, E M

    2011-01-15

    Hyaluronan (HA), a glycosaminoglycan, is a major component of the pericellular matrix which envelopes mammalian cells. Binding of hyaluronan to one of its specific receptors, CD44, modulates transduction of intracellular signals which direct a variety of processes, including embryogenesis, wound healing, inflammation, and neoplasia. Since regulation of these processes is critical to equine reproductive success, localization of constitutive CD44 expression was evaluated by immunohistochemical methods in ovarian, oviductal, and uterine tissues from healthy mares. Ovarian stroma contained thecal cells with varying CD44 immunopositivity. Follicular and granulosa cells of some antral and atretic follicles were positive for CD44. In the oviduct, the luminal epithelium was variably positive for CD44, with overall decreasing intensity of immunostaining from the infundibulum to the isthmus. The CD44 molecule was expressed strongly by surface epithelial cells of the uterine endometrium, but was present only rarely among cells of uterine glands. In addition, CD44 was expressed by smooth muscle cells of vascular walls, oviduct, and uterus. Since CD44 is known to modulate cell movement and differentiation, and was present at multiple sites in the reproductive tract of normal mares, we inferred there may be an important role for the HA-CD44 signaling pathway in reproductive function and inflammation. PMID:20932561

  18. CD44-engineered mesoporous silica nanoparticles for overcoming multidrug resistance in breast cancer

    NASA Astrophysics Data System (ADS)

    Wang, Xin; Liu, Ying; Wang, Shouju; Shi, Donghong; Zhou, Xianguang; Wang, Chunyan; Wu, Jiang; Zeng, Zhiyong; Li, Yanjun; Sun, Jing; Wang, Jiandong; Zhang, Longjiang; Teng, Zhaogang; Lu, Guangming

    2015-03-01

    Multidrug resistance is a major impediment for the successful chemotherapy in breast cancer. CD44 is over-expressed in multidrug resistant human breast cancer cells. CD44 monoclonal antibody exhibits anticancer potential by inhibiting proliferation and regulating P-glycoprotein-mediated drug efflux activity in multidrug resistant cells. Thereby, CD44 monoclonal antibody in combination with chemotherapeutic drug might be result in enhancing chemosensitivity and overcoming multidrug resistance. The purpose of this study is to investigate the effects of the CD44 monoclonal antibody functionalized mesoporous silica nanoparticles containing doxorubicin on human breast resistant cancer MCF-7 cells. The data showed that CD44-modified mesoporous silica nanoparticles increased cytotoxicity and enhanced the downregulation of P-glycoprotein in comparison to CD44 antibody. Moreover, CD44-engineered mesoporous silica nanoparticles provided active target, which promoted more cellular uptake of DOX in the resistant cells and more retention of DOX in tumor tissues than unengineered counterpart. Animal studies of the resistant breast cancer xenografts demonstrated that CD44-engineered drug delivery system remarkably induced apoptosis and inhibited the tumor growth. Our results indicated that the CD44-engineered mesoporous silica nanoparticle-based drug delivery system offers an effective approach to overcome multidrug resistance in human breast cancer.

  19. A self-enforcing CD44s/ZEB1 feedback loop maintains EMT and stemness properties in cancer cells.

    PubMed

    Preca, Bogdan-Tiberius; Bajdak, Karolina; Mock, Kerstin; Sundararajan, Vignesh; Pfannstiel, Jessica; Maurer, Jochen; Wellner, Ulrich; Hopt, Ulrich T; Brummer, Tilman; Brabletz, Simone; Brabletz, Thomas; Stemmler, Marc P

    2015-12-01

    Invasion and metastasis of carcinomas are often activated by induction of aberrant epithelial-mesenchymal transition (EMT). This is mainly driven by the transcription factor ZEB1, promoting tumor-initiating capacity correlated with increased expression of the putative stem cell marker CD44. However, the direct link between ZEB1, CD44 and tumourigenesis is still enigmatic. Remarkably, EMT-induced repression of ESRP1 controls alternative splicing of CD44, causing a shift in the expression from the variant CD44v to the standard CD44s isoform. We analyzed whether CD44 and ZEB1 regulate each other and show that ZEB1 controls CD44s splicing by repression of ESRP1 in breast and pancreatic cancer. Intriguingly, CD44s itself activates the expression of ZEB1, resulting in a self-sustaining ZEB1 and CD44s expression. Activation of this novel CD44s-ZEB1 regulatory loop has functional impact on tumor cells, as evident by increased tumor-sphere initiation capacity, drug-resistance and tumor recurrence. In summary, we identified a self-enforcing feedback loop that employs CD44s to activate ZEB1 expression. This renders tumor cell stemness independent of external stimuli, as ZEB1 downregulates ESRP1, further promoting CD44s isoform synthesis. PMID:26077342

  20. Binding of human leukocytes to fibronectin is augmented by an anti-CD44 mAb (TL-1) and blocked by another anti-CD44 mAb (Hermes-3) but not by anti-VLA-4/VLA-5 mAbs.

    PubMed

    Cao, L; Yoshino, T; Kawasaki, N; Yanai, H; Kawahara, K; Kondo, E; Omonishi, K; Takahashi, K; Akagi, T

    Fibronectin (FN) forms meshworks in extracellular spaces, and it plays an important role in cellular trafficking. Lymphoid cells are activated by binding to FN of the VLA-4 and VLA-5 receptors. CD44 also acts as a receptor of FN, but the mechanism and physiologic regulation of their binding are poorly understood. We have developed an anti-CD44 monoclonal antibody (mAb) (TL-1) in which lymphoid cells are activated and form homotypic cell aggregation. In this study, we found that the adhesion of CEM, HSB2, and LAD lymphoid cells to FN was augmented by TL-1 treatment and was apparently blocked by another anti-CD44 mAb (Hermes-3), but TL-1 Fab' fragments treatment did not induce FN-binding. A similar phenomenon is reported in the binding of the CD44 molecule to HA. This augmentation was not inhibited by the CS1 and RGD peptides of FN or by anti-VLA-4 and -VLA-5 mAbs; it was energy-dependent and associated with cytoplasmic actin filaments. Tl-1 treatment did not alter the cell surface expression of CD44 molecules. These findings above suggested that activated and/or altered cell surface distribution of CD44 molecules via a conformational change augmented the avidity of its binding to FN, which may be similar to lymphocyte-hyaluronate and lymphocyte-endothelial cell binding. As the Hermes-3 binding site is also involved in the interaction between lymphocytes and endothelial cells, activation of lymphocytes via CD44 molecules may facilitate the binding of lymphocytes to endothelial cells, extravasation, and migration to inflammatory sites rich in FN. PMID:9145328

  1. CD44: molecular interactions, signaling and functions in the nervous system.

    PubMed

    Dzwonek, Joanna; Wilczynski, Grzegorz M

    2015-01-01

    CD44 is the major surface hyaluronan (HA) receptor implicated in intercellular and cell-matrix adhesion, cell migration and signaling. It is a transmembrane, highly glycosylated protein with several isoforms resulting from alternative gene splicing. The CD44 molecule consists of several domains serving different functions: the N-terminal extracellular domain, the stem region, the transmembrane domain and the C-terminal tail. In the nervous system, CD44 expression occurs in both glial and neuronal cells. The role of CD44 in the physiology and pathology of the nervous system is not entirely understood, however, there exists evidence suggesting it might be involved in the axon guidance, cytoplasmic Ca(2+) clearance, dendritic arborization, synaptic transmission, epileptogenesis, oligodendrocyte and astrocyte differentiation, post-traumatic brain repair and brain tumour development. PMID:25999819

  2. Production and characterization of a peptide-based monoclonal antibody against CD44 variant 6.

    PubMed

    Zarei, Saeed; Bayat, Ali Ahmad; Hadavi, Reza; Mahmoudi, Ahmad R; Tavangar, Banafsheh; Vojgani, Yasaman; Jeddi-Tehrani, Mahmood; Amirghofran, Zahra

    2015-02-01

    The gene that codes for the CD44 family members consists of 20 exons, nine of which encode the standard form of the molecule. The other exons can be inserted in various combinations into the membrane proximal region of the extracellular domain of the protein, giving rise to variant isoforms (CD44v). CD44 variants, especially the CD44v6, have been reported to regulate tumor invasion, progression, and metastasis of carcinomas. Producing a high affinity monoclonal antibody against human CD44v6 provides a powerful tool to monitor and trace CD44v6 function in different biological fluids. In this study, a synthetic peptide from CD44v6 was conjugated to keyhole limpet hemocyanin (KLH) and injected into BALB/c mice. Splenocytes from the immunized mice were fused with murine SP2/0 myeloma cells followed by selection of antibody producing hybridoma cells. After screening of hybridoma colonies by ELISA, high affinity antibodies were selected and purified by affinity chromatography. Western blot, immunocytochemistry, and flow cytometry experiments were used to characterize the antibodies. Six stable hybridoma cell lines, designated as 1H1, 1H2, 2A12, 2G11, 3H3, and 3H7, were obtained. Flow cytometry and immunocytochemistry results showed that the new monoclonal antibodies recognized CD44v6 on the cell surface. This novel panel of anti-CD44v6 antibodies has the potential for investigating the role of CD44v6 in cancer pathogenesis. PMID:25723282

  3. Production and Characterization of a Peptide-based Monoclonal Antibody Against CD44 Variant 6

    PubMed Central

    Zarei, Saeed; Bayat, Ali Ahmad; Hadavi, Reza; Mahmoudi, Ahmad R.; Tavangar, Banafsheh; Vojgani, Yasaman; Jeddi-Tehrani, Mahmood

    2015-01-01

    The gene that codes for the CD44 family members consists of 20 exons, nine of which encode the standard form of the molecule. The other exons can be inserted in various combinations into the membrane proximal region of the extracellular domain of the protein, giving rise to variant isoforms (CD44v). CD44 variants, especially the CD44v6, have been reported to regulate tumor invasion, progression, and metastasis of carcinomas. Producing a high affinity monoclonal antibody against human CD44v6 provides a powerful tool to monitor and trace CD44v6 function in different biological fluids. In this study, a synthetic peptide from CD44v6 was conjugated to keyhole limpet hemocyanin (KLH) and injected into BALB/c mice. Splenocytes from the immunized mice were fused with murine SP2/0 myeloma cells followed by selection of antibody producing hybridoma cells. After screening of hybridoma colonies by ELISA, high affinity antibodies were selected and purified by affinity chromatography. Western blot, immunocytochemistry, and flow cytometry experiments were used to characterize the antibodies. Six stable hybridoma cell lines, designated as 1H1, 1H2, 2A12, 2G11, 3H3, and 3H7, were obtained. Flow cytometry and immunocytochemistry results showed that the new monoclonal antibodies recognized CD44v6 on the cell surface. This novel panel of anti-CD44v6 antibodies has the potential for investigating the role of CD44v6 in cancer pathogenesis. PMID:25723282

  4. CD44 expression in normal adrenal tissue and adrenal tumours.

    PubMed Central

    Barshack, I; Goldberg, I; Nass, D; Olchovsky, D; Kopolovic, J

    1998-01-01

    BACKGROUND: CD44 is a cell surface glycoprotein found on many normal cells, mainly lymphoid and epithelial. Normal cells usually express standard CD44 (CD44-S), whereas malignant tumours may express CD44 variant isoforms (CD44-V). CD44 expression has been described for neural crest derivatives. Characterisation of differences in CD44 expression may help in the diagnosis and differentiation of distinct adrenal tumours. AIMS: To examine CD44 expression in different layers of cortical cortex, in adrenal medulla, and in adrenal tumours. METHODS: CD44-S and CD44-V6 expression were studied in 12 cases of adrenal cortical adenoma, 3 of adrenal cortical carcinoma, 10 of pheochromocytoma, and 4 normal adrenal glands. RESULTS: CD44-V6 staining showed cytoplasmic expression in normal adrenal cortex and in cortical adenomas and carcinomas. Pheochromocytomas also showed CD44-V6 expression but in 5 of the 10 cases it was sparse, focal, and sometimes perinuclear. Strong membranous staining for CD44-S was observed in normal adrenal medulla. Analysis of CD44-S expression revealed differences between cortical adrenal tumours and pheochromocytomas. Ten of 12 cortical adenomas and 2 of 3 cortical carcinoma cells showed weak to moderate cytoplasmic staining, but all cases of pheochromocytoma had strong membranous staining. CONCLUSIONS: Membranous CD44-S staining may help to distinguish pheochromocytoma from adrenal cortical adenoma. Images PMID:9577373

  5. Influence of Intron Length on Alternative Splicing of CD44

    PubMed Central

    Bell, Martyn V.; Cowper, Alison E.; Lefranc, Marie-Paule; Bell, John I.; Screaton, Gavin R.

    1998-01-01

    Although the splicing of transcripts from most eukaryotic genes occurs in a constitutive fashion, some genes can undergo a process of alternative splicing. This is a genetically economical process which allows a single gene to give rise to several protein isoforms by the inclusion or exclusion of sequences into or from the mature mRNA. CD44 provides a unique example; more than 1,000 possible isoforms can be produced by the inclusion or exclusion of a central tandem array of 10 alternatively spliced exons. Certain alternatively spliced exons have been ascribed specific functions; however, independent regulation of the inclusion or skipping of each of these exons would clearly demand an extremely complex regulatory network. Such a network would involve the interaction of many exon-specific trans-acting factors with the pre-mRNA. Therefore, to assess whether the exons are indeed independently regulated, we have examined the alternative exon content of a large number of individual CD44 cDNA isoforms. This analysis shows that the downstream alternatively spliced exons are favored over those lying upstream and that alternative exons are often included in blocks rather than singly. Using a novel in vivo alternative splicing assay, we show that intron length has a major influence upon the alternative splicing of CD44. We propose a kinetic model in which short introns may overcome the poor recognition of alternatively spliced exons. These observations suggest that for CD44, intron length has been exploited in the evolution of the genomic structure to enable tissue-specific patterns of splicing to be maintained. PMID:9742110

  6. CD44 variant 6 is correlated with peritoneal dissemination and poor prognosis in patients with advanced epithelial ovarian cancer

    PubMed Central

    Tjhay, Francisca; Motohara, Takeshi; Tayama, Shingo; Narantuya, Dashdemberel; Fujimoto, Koichi; Guo, Jianying; Sakaguchi, Isao; Honda, Ritsuo; Tashiro, Hironori; Katabuchi, Hidetaka

    2015-01-01

    Cancer stem cells (CSCs) drive tumor initiation and metastasis in several types of human cancer. However, the contribution of ovarian CSCs to peritoneal metastasis remains unresolved. The cell adhesion molecule CD44 has been identified as a major marker for CSCs in solid tumors, including epithelial ovarian cancer. CD44 exists as a standard form (CD44s) and also as numerous variant isoforms (CD44v) generated by alternative mRNA splicing. Here we show that disseminated ovarian tumors in the pelvic peritoneum contain highly enriched CD44v6-positive cancer cells, which drive tumor metastasis and are responsible for tumor resistance to chemotherapy. Clinically, an increased number of CD44v6-positive cancer cells in primary tumors was associated with a shortened overall survival in stage III–IV ovarian cancer patients. Furthermore, a subpopulation of CD44v6-positive cancer cells manifested the ability to initiate tumor metastasis in the pelvic peritoneum in an in vivo mouse model, suggesting that CD44v6-positive cells show the potential to serve as metastasis-initiating cells. Thus, the peritoneal disseminated metastasis of epithelial ovarian cancer is initiated by the CD44v6-positive subpopulation, and CD44v6 expression is a biomarker for the clinical outcome of advanced ovarian cancer patients. Given that a distinct subpopulation of CD44v6-positive cancer cells plays a critical role in peritoneal metastasis, definitive treatment should target this subpopulation of CD44v6-positive cells in epithelial ovarian cancer. PMID:26250934

  7. MicroRNA‑143 targets CD44 to inhibit breast cancer progression and stem cell-like properties.

    PubMed

    Yang, Zhuangqing; Chen, Dedian; Nie, Jianyun; Zhou, Shaoqiang; Wang, Jiankui; Tang, Qi; Yang, Xiaojuan

    2016-06-01

    CD44 is closely linked to breast cancer progression; however, the regulatory functions of microRNAs (miRs) in breast cancer have yet to be fully elucidated. In order to investigate the regulation of CD44 by miRs in breast cancer, the present study isolated CD44+ and CD44- breast cancer cells by flow cytometry, revealing that CD44+ cells were enriched in transplanted compared with those in primary breast cancers, and that their proliferation and stem-cell sphere formation ability were enhanced. A miRNA array assay indicated that miR-143 expression in CD44+ breast cancer cells was lower than that in CD44- cells. Furthermore, miR-143 was decreased in breast cancer tissues and cell lines compared with that in normal tissues and cells. Restoration of miR-143 expression in CD44+ breast cancer cells inhibited their proliferation and sphere formation. A luciferase reporter assay demonstrated that miR-143 directly tartgeted the 3'-untranslated region of CD44. In addition, miR-143 inhibited metastasis-associated features in breast cancer and reduced tumor growth in a mouse model of breast cancer. In conclusion, the results of the present study demonstrated that miR-143 inhibited the progression and stem-cell properties of breast cancer cells by targeting CD44. PMID:27121210

  8. CD44 increases the efficiency of distant metastasis of breast cancer.

    PubMed

    McFarlane, Suzanne; Coulter, Jonathan A; Tibbits, Paul; O'Grady, Anthony; McFarlane, Cheryl; Montgomery, Nicola; Hill, Ashleigh; McCarthy, Helen O; Young, Leonie S; Kay, Elaine W; Isacke, Clare M; Waugh, David J J

    2015-05-10

    Metastasis is the predominant cause of death from cancer yet we have few biomarkers to predict patients at increased risk of metastasis and are unable to effectively treat disseminated disease. Analysis of 448 primary breast tumors determined that expression of the hylauronan receptor CD44 associated with high grade (p = 0.046), ER- (p = 0.001) and PR-negative tumors (p = 0.029), and correlated with increased distant recurrence and reduced disease-free survival in patients with lymph-node positive or large tumors. To determine its functional role in distant metastasis, CD44 was knocked-down in MDA-MB-231 cells using two independent shRNA sequences. Loss of CD44 attenuated tumor cell adhesion to endothelial cells and reduced cell invasion but did not affect proliferation in vitro. To verify the importance of CD44 to post-intravasation events, tumor formation was assessed by quantitative in vivo imaging and post-mortem tissue analysis following an intra-cardiac injection of transfected cells. CD44 knock-down increased survival and decreased overall tumor burden at multiple sites, including the skeleton in vivo. We conclude that elevated CD44 expression on tumour cells within the systemic circulation increases the efficiency of post-intravasation events and distant metastasis in vivo, consistent with its association with increased distant recurrence and reduced disease-free survival in patients. PMID:25888636

  9. Expression of osteopontin and CD44 molecule in papillary renal cell tumors.

    PubMed

    Matusan, Koviljka; Dordevic, Gordana; Mozetic, Vladimir; Lucin, Ksenija

    2005-01-01

    The aim of the study was to analyze the expression of CD44 adhesion molecule and its ligand osteopontin in papillary renal cell tumors, and to assess the possible prognostic significance of CD44 and osteopontin expression in papillary renal cell carcinomas. The expression of the standard and v6 exon containing isoforms of CD44 molecule, as well as of its ligand osteopontin, was immunohistochemically evaluated in 43 papillary renal cell tumors, which included 5 adenomas and 38 carcinomas. In order to assess their prognostic significance, the results obtained in papillary renal cell carcinomas were compared to usual clinicopathological parameters such as tumor size, histological grade, pathological stage, and Ki-67 proliferation index. Normal renal tissue was negative for CD44s and v6 isoforms, while the expression of osteopontin was found in distal tubular epithelial cells in the form of cytoplasmic granular positivity. CD44s and v6 isoforms were upregulated in 22 (58%) and 12 (32%) out of 38 carcinomas, respectively. Among all clinicopathological parameters examined, we only found significant association of CD44s-positive carcinomas with lower pathological stage (p=0.026). Papillary renal cell adenomas were generally negative for CD44s, except for focal positivity found in one sample. The osteopontin protein was detected in all adenomas and all papillary renal cell carcinomas, except one. Our results show constitutive expression of osteopontin in papillary renal tumors, including papillary renal cell adenomas. The upregulation of CD44s and v6 isoforms, although found in a considerable number of papillary renal cell carcinomas, does not appear to have any prognostic value in this type of renal cancer. PMID:15999156

  10. Meta-Analysis of Prognostic and Clinical Significance of CD44v6 in Esophageal Cancer.

    PubMed

    Hu, Bangli; Luo, Wei; Hu, Rui-Ting; Zhou, You; Qin, Shan-Yu; Jiang, Hai-Xing

    2015-08-01

    CD44v6 is a cell adhesion molecule that plays an important role in the development and progression of esophageal cancer. However, the prognostic value and clinical significance of CD44v6 in esophageal cancer remains controversial. In the present study, we aimed to clarify these relationships through a meta-analysis.We performed a comprehensive search of studies from PubMed, EMBASE, Ovid library database, Google scholar, and Chinese National Knowledge Infrastructure databases that were published before June 2015. The odds ratio (OR) and pooled hazard ratio (HR) with the 95% confidence intervals (CI) were used to estimate the effects.Twenty-one studies including 1504 patients with esophageal cancer were selected to assess the prognostic value and clinical significance of CD44v6 in these patients. The results showed that the expression of CD44v6 was higher in esophageal cancer tissue than in normal colorectal tissue (OR=9.19, 95% CI=6.30-13.42). Moreover, expression of CD44v6 was higher in patients with lymphoid nodal metastasis, compared to those without (OR=6.91, 95% CI=4.81-9.93). The pooled results showed that CD44v6 was associated with survival in patients with esophageal cancer (HR = 2.47, 95% CI = 1.56-3.92). No significant difference in CD44v6 expression was found in patients with different histological types and tumor stages (both P>0.05). Moreover, no publication bias was found among the studies (all P > 0.05).This meta-analysis demonstrates that CD44v6 is associated with the metastasis of esophageal cancer and a poor prognosis, but is not associated with the histological types and tumor stages. PMID:26252284

  11. Identification and Characterization of CD44RC, a Novel Alternatively Spliced Soluble CD44 Isoform that can Potentiate the Hyaluronan Binding Activity of Cell Surface CD44

    PubMed Central

    Chiu, Roland K; Carpenito, Carmine; Dougherty, Shona T; Hayes, Gregory M; Dougherty, Graeme J

    1999-01-01

    Abstract Soluble CD44 proteins generated by proteolytic cleavage or aberrant intron retention have been shown to antagonize the ligand binding activity of the corresponding cell surface receptor, inducing apoptosis and inhibiting tumor growth. Interestingly, such findings appear to contradict recent studies demonstrating a correlation between the presence of high levels of soluble CD44 in the serum of cancer patients and poor prognosis. In the present study, we report the cloning of a novel, naturally occurring, differentially expressed, soluble CD44 isoform, designated CD44RC, which, in contrast to previously described soluble CD44 proteins, can dramatically enhance the hyaluronan binding activity of cell surface CD44. Sequence analysis suggests that CD44RC is generated by an alternative splicing event in which the 3′ end of CD44 exon 2 is spliced into an internal splice acceptor site present within exon 18, altering reading frame and giving rise to a soluble protein with a unique COOH terminus. Functional studies suggest that CD44RC enhances hyaluronan binding by adhering to chondroitin sulfate side-chains attached to cell surface CD44, generating a multivalent complex with increased avidity for hyaluronan. PMID:10933060

  12. Anticancer Therapeutics: Targeting Macromolecules and Nanocarriers to Hyaluronan or CD44, a Hyaluronan Receptor

    PubMed Central

    Platt, Virginia M.; Szoka, Francis C.

    2009-01-01

    The complex system involved in the synthesis, degradation, and binding of the high molecular weight glycosaminoglycan hyaluronic acid (hyaluronan or HA) provides a variety of structures that can be exploited for targeted cancer therapy. In many cancers of epithelial origin there is an up-regulation of CD44, a receptor that binds HA. In other cancers, HA in the tumor matrix is over-expressed. Both CD44 on cancer cells and HA in the matrix have been targets for anti-cancer therapy. Even though CD44 is expressed in normal epithelial cells and HA is part of the matrix of normal tissues, selective targeting to cancer is possible. This is because macromolecular carriers predominantly extravasate into the tumor and not normal tissue; thus CD44-HA targeted carriers administered intravenously localize preferentially into tumors. Anti-CD44 antibodies have been used in patients to deliver radioisotopes or mertansine for treatment of CD44 expressing tumors. In early phase clinical trials, patients with breast or head and neck tumors treated with anti-CD44 conjugates experienced stabilized disease. A dose-limiting toxicity was associated with distribution of the antibody-drug conjugate to the skin, a site in the body with a high level of CD44. HA has been used as a drug carrier and a ligand on liposomes or nanoparticles to target drugs to CD44 over-expressing cells. Drugs can be attached to HA via the carboxylate on the glucuronic acid residue, the hydroxyl on the N-acetylglucosamine, or the reducing end which are located on a repeating disaccharide. Drugs delivered in HA-modified liposomes exhibited excellent anti-tumor activity both in vitro and in murine tumor models. The HA matrix is also a potential target for anti-cancer therapies. By manipulating the interaction of HA with cell surface receptors, either by degrading it with hyaluronidase or by interfering with CD44-HA interactions using soluble CD44 proteins, tumor progression was blocked. Finally, cytotoxic drugs or pro

  13. Inversed relationship between CD44 variant and c-Myc due to oxidative stress-induced canonical Wnt activation

    SciTech Connect

    Yoshida, Go J. Saya, Hideyuki

    2014-01-10

    Highlights: •CD44 variant8–10 and c-Myc are inversely expressed in gastric cancer cells. •Redox-stress enhances c-Myc expression via canonical Wnt signal. •CD44v, but not CD44 standard, suppresses redox stress-induced Wnt activation. •CD44v expression promotes both transcription and proteasome degradation of c-Myc. •Inversed expression pattern between CD44v and c-Myc is often recognized in vivo. -- Abstract: Cancer stem-like cells express high amount of CD44 variant8-10 which protects cancer cells from redox stress. We have demonstrated by immunohistochemical analysis and Western blotting, and reverse-transcription polymerase chain reaction, that CD44 variant8-10 and c-Myc tend to show the inversed expression manner in gastric cancer cells. That is attributable to the oxidative stress-induced canonical Wnt activation, and furthermore, the up-regulation of the downstream molecules, one of which is oncogenic c-Myc, is not easily to occur in CD44 variant-positive cancer cells. We have also found out that CD44v8-10 expression is associated with the turn-over of the c-Myc with the experiments using gastric cancer cell lines. This cannot be simply explained by the model of oxidative stress-induced Wnt activation. CD44v8-10-positive cancer cells are enriched at the invasive front. Tumor tissue at the invasive area is considered to be composed of heterogeneous cellular population; dormant cancer stem-like cells with CD44v8-10 {sup high}/ Fbw7 {sup high}/ c-Myc {sup low} and proliferative cancer stem-like cells with CD44v8-10 {sup high}/ Fbw7 {sup low}/ c-Myc {sup high}.

  14. Effect of CD44 gene polymorphisms on risk of transitional cell carcinoma of the urinary bladder in Taiwan.

    PubMed

    Weng, Wei-Chun; Huang, Yu-Hui; Yang, Shun-Fa; Wang, Shian-Shiang; Kuo, Wu-Hsien; Hsueh, Chao-Wen; Huang, Ching-Hsuan; Chou, Ying-Erh

    2016-05-01

    The carcinogenesis of transitional cell carcinoma (TCC) of the urinary bladder involves etiological factors, such as ethnicity, the environment, genetics, and diet. Cluster of differentiation (CD44), a well-known tumor marker, plays a crucial role in regulating tumor cell differentiation and metastasis. This study investigated the effect of CD44 single nucleotide polymorphisms (SNPs) on TCC risk and clinicopathological characteristics. Five SNPs of CD44 were analyzed through real-time polymerase chain reaction in 275 patients with TCC and 275 participants without cancer. In this study, we observed that CD44 rs187115 polymorphism carriers with the genotype of at least one G were associated with TCC risk. Furthermore, TCC patients who carried at least one G allele at CD44 rs187115 had a higher stage risk than did patients carrying the wild-type allele (p < 0.05). In addition, The AATAC or GACGC haplotype among the five CD44 sites was also associated with a reduced risk of TCC. In conclusion, our results suggest that CD44 SNPs influence the risk of TCC. Patients with CD44 rs187115 variant genotypes (AG + GG) exhibited a higher risk of TCC; these patients may possess chemoresistance to developing late-stage TCC compared with those with the wild-type genotype. The CD44 rs187115 SNP may predict poor prognosis in patients with TCC. PMID:26662954

  15. Impacts of CD44 knockdown in cancer cells on tumor and host metabolic systems revealed by quantitative imaging mass spectrometry.

    PubMed

    Ohmura, Mitsuyo; Hishiki, Takako; Yamamoto, Takehiro; Nakanishi, Tsuyoshi; Kubo, Akiko; Tsuchihashi, Kenji; Tamada, Mayumi; Toue, Sakino; Kabe, Yasuaki; Saya, Hideyuki; Suematsu, Makoto

    2015-04-30

    CD44 expressed in cancer cells was shown to stabilize cystine transporter (xCT) that uptakes cystine and excretes glutamate to supply cysteine as a substrate for reduced glutathione (GSH) for survival. While targeting CD44 serves as a potentially therapeutic stratagem to attack cancer growth and chemoresistance, the impact of CD44 targeting in cancer cells on metabolic systems of tumors and host tissues in vivo remains to be fully determined. This study aimed to reveal effects of CD44 silencing on alterations in energy metabolism and sulfur-containing metabolites in vitro and in vivo using capillary electrophoresis-mass spectrometry and quantitative imaging mass spectrometry (Q-IMS), respectively. In an experimental model of xenograft transplantation of human colon cancer HCT116 cells in superimmunodeficient NOG mice, snap-frozen liver tissues containing metastatic tumors were examined by Q-IMS. As reported previously, short hairpin CD44 RNA interference (shCD44) in cancer cells caused significant regression of tumor growth in the host liver. Under these circumstances, the CD44 knockdown suppressed polyamines, GSH and energy charges not only in metastatic tumors but also in the host liver. In culture, HCT116 cells treated with shCD44 decreased total amounts of methionine-pool metabolites including spermidine and spermine, and reactive cysteine persulfides, suggesting roles of these metabolites for cancer growth. Collectively, these results suggest that CD44 expressed in cancer accounts for a key regulator of metabolic interplay between tumor and the host tissue. PMID:25461272

  16. Suppression of human breast tumors in NOD/SCID mice by CD44 shRNA gene therapy combined with doxorubicin treatment

    PubMed Central

    Van Pham, Phuc; Vu, Ngoc Bich; Duong, Thuy Thanh; Nguyen, Tam Thanh; Truong, Nhung Hai; Phan, Nhan Lu Chinh; Vuong, Tue Gia; Pham, Viet Quoc; Nguyen, Hoang Minh; Nguyen, Kha The; Nguyen, Nhung Thi; Nguyen, Khue Gia; Khat, Lam Tan; Van Le, Dong; Truong, Kiet Dinh; Phan, Ngoc Kim

    2012-01-01

    Background Breast cancer stem cells with a CD44+CD24− phenotype are the origin of breast tumors. Strong CD44 expression in this population indicates its important role in maintaining the stem cell phenotype. Previous studies show that CD44 down-regulation causes CD44+CD24− breast cancer stem cells to differentiate into non-stem cells that are sensitive to antitumor drugs and lose many characteristics of the original cells. In this study, we determined tumor suppression in non-obese severe combined immunodeficiency mice using CD44 shRNA therapy combined with doxorubicin treatment. Methods Tumor-bearing non-obese severe combined immunodeficiency mice were established by injection of CD44+CD24− cells. To track CD44+CD24− cells, green fluorescence protein was stably transduced using a lentiviral vector prior to injection into mice. The amount of CD44 shRNA lentiviral vector used for transduction was based on CD44 down-regulation by in vitro CD44 shRNA transduction. Mice were treated with direct injection of CD44 shRNA lentiviral vector into tumors followed by doxorubicin administration after 48 hours. The effect was evaluated by changes in the size and weight of tumors compared with that of the control. Results The combination of CD44 down-regulation and doxorubicin strongly suppressed tumor growth with significant differences in tumor sizes and weights compared with that of CD44 down-regulation or doxorubicin treatment alone. In the combination of CD44 down-regulation and doxorubicin group, the tumor weight was significantly decreased by 4.38-fold compared with that of the control group. Conclusion These results support a new strategy for breast cancer treatment by combining gene therapy with chemotherapy. PMID:22649280

  17. The microRNA miR-34a inhibits non-small cell lung cancer (NSCLC) growth and the CD44hi stem-like NSCLC cells.

    PubMed

    Shi, Yang; Liu, Can; Liu, Xin; Tang, Dean G; Wang, Junchen

    2014-01-01

    Lung cancer is among the most lethal malignancies with a high metastasis and recurrence rate, which is probably due to the existence of lung cancer stem cells (CSCs). CSCs in many tumors including non-small cell lung cancer (NSCLC) have been identified using adhesion molecular CD44, either individually or in combination with other marker(s). MicroRNAs (miRNAs) regulate both normal stem cells and CSCs and dysregulation of miRNAs has been implicated in tumorigenesis. Recently, miR-34a was found to be downregulated in NSCLC cells but the biological functions of miR-34a in regulating NSCLC cell behavior have not been extensively studied. Here we show that transfection of synthetic miR-34a, but not the negative control (NC) miRNA oligonucleotides (oligos) in three NSCLC cell lines, i.e., A549, H460, and H1299, inhibited their holoclone formation, clonogenic expansion, and tumor regeneration in vivo. Furthermore, the lentiviral vector-mediated overexpression of miR-34a in purified CD44hi H460 cells also inhibited tumor outgrowth. In contrast, expression of miR-34a antagomirs (i.e., antisense oligos) in the CD44lo H460 cells promoted tumor development. Our study shows that miR-34a is a negative regulator of the tumorigenic properties of NSCLC cells and CD44hi lung CSCs, and establishes a strong rationale for developing miR-34a as a novel therapeutic agent against NSCLC. PMID:24595209

  18. Overexpression of c-Met and CD44v6 receptors contributes to autocrine TGF-β1 signaling in interstitial lung disease.

    PubMed

    Ghatak, Shibnath; Bogatkevich, Galina S; Atnelishvili, Ilia; Akter, Tanjina; Feghali-Bostwick, Carol; Hoffman, Stanley; Fresco, Victor M; Fuchs, John C; Visconti, Richard P; Markwald, Roger R; Padhye, Subhas B; Silver, Richard M; Hascall, Vincent C; Misra, Suniti

    2014-03-14

    The hepatocyte growth factor (HGF) and the HGF receptor Met pathway are important in the pathogenesis of interstitial lung disease (ILD). Alternatively spliced isoforms of CD44 containing variable exon 6 (CD44v6) and its ligand hyaluronan (HA) alter cellular function in response to interaction between CD44v6 and HGF. TGF-β1 is the crucial cytokine that induces fibrotic action in ILD fibroblasts (ILDFbs). We have identified an autocrine TGF-β1 signaling that up-regulates both Met and CD44v6 mRNA and protein expression. Western blot analysis, flow cytometry, and immunostaining revealed that CD44v6 and Met colocalize in fibroblasts and in tissue sections from ILD patients and in lungs of bleomycin-treated mice. Interestingly, cell proliferation induced by TGF-β1 is mediated through Met and CD44v6. Further, cell proliferation mediated by TGF-β1/CD44v6 is ERK-dependent. In contrast, action of Met on ILDFb proliferation does not require ERK but does require p38(MAPK). ILDFbs were sorted into CD44v6(+)/Met(+) and CD44v6(-)/Met(+) subpopulations. HGF inhibited TGF-β1-stimulated collagen-1 and α-smooth muscle cell actin expression in both of these subpopulations by interfering with TGF-β1 signaling. HGF alone markedly stimulated CD44v6 expression, which in turn regulated collagen-1 synthesis. Our data with primary lung fibroblast cultures with respect to collagen-1, CD44v6, and Met expressions were supported by immunostaining of lung sections from bleomycin-treated mice and from ILD patients. These results define the relationships between CD44v6, Met, and autocrine TGF-β1 signaling and the potential modulating influence of HGF on TGF-β1-induced CD44v6-dependent fibroblast function in ILD fibrosis. PMID:24324260

  19. Staurosporine Induced Apoptosis May Activate Cancer Stem-Like Cells (CD44+/CD24-) in MCF-7 by Upregulating Mucin1 and EpCAM

    PubMed Central

    Zhou, Na; Wang, Rong; Zhang, Yizhuang; Lei, Zhen; Zhang, Xuehui; Hu, Ruobi; Li, Hui; Mao, Yiqing; Wang, Xi; Irwin, David M.; Niu, Gang; Tan, Huanran

    2015-01-01

    Malignant tumors recur after chemotherapy. A small population of cancer stem-like cells within tumors is now generally considered the prime source of the recurrence. To better understand how cancer stem-like cells induce relapse after fractionated chemotherapy, we examined changes in the CD44+/CD24- cancer stem-like cells population and behavior using the breast cancer cell line MCF-7. Our results show that apart from an increase in the CD44+/CD24- population, proliferation and clone formation, but not migration, were enhanced after recovery from apoptosis induced by two pulses of staurosporine (STS). The distribution of cells in the cell cycle differed between acutely induced apoptosis and fractionated chemotherapy. Sorted CD44+/CD24- stem-like cells from MCF-7 cells recovered from STS treatment possessed greater proliferation abilities. We also observed that mucin1 (MUC1) and Epithelial cell adhesion molecule (EpCAM) were up-regulated in abundance coincidently with proliferation and clone formation enhancement. Our findings suggest that fractionated chemotherapy induced apoptosis could stimulate cancer stem-like cell to behave with a stronger malignant property than cancer cells themselves and MUC1 and EpCAM are important factors involving in this process. By demonstrating changes in cancer stem cell during chemotherapy and identifying the crucial factors, we potentially can target them, to eradicate tumors and overcome cancer relapse. PMID:26366219

  20. Quantitative immunohistochemical analyses of the expression of E-cadherin, thrombomodulin, CD44H and CD44v6 in primary tumours of pharynx/larynx squamous cell carcinoma and their lymph node metastases.

    PubMed

    Hernández Gaspar, R; de los Toyos, J R; Alvarez Marcos, C; Riera, J R; Sampedro, A

    1999-01-01

    The quantitative expression of E-cadherin, thrombomodulin, CD44H and CD44v6 in 32 specimens of primary tumours of pharynx/larynx squamous cell carcinoma and their lymph node metastases was studied by immunohistochemistry. With the aim of obtaining comparative and objective data, image acquisition conditions were kept unaltered for all the measurements and the immunostaining intensity was quantified by applying an image processing system. On the one hand, correlations were only observed between CD44H and CD44v6, both in primary tumours and metastases, and between E-cadherin and TM in metastases. On the other hand, statistical analyses of paired data did not show significant differences in the expression of these markers between the two tumour sites. In agreement with previous reports, E-cadherin expression was rather low or negative in primary tumours and metastases of the three poorly differentiated specimens we studied, as well as that of TM, but otherwise some of these samples showed intermediate immunostaining levels of CD44H/CD44v6. It may be concluded from the present study that the quantitative expression of these adhesion molecules in well established lymph node metastases of pharynx/larynx squamous cell carcinoma is essentially unaltered in relation to their primary sites. PMID:10609562

  1. CD82 Restrains Angiogenesis by Altering Lipid Raft Clustering and CD44 Trafficking in Endothelial Cells

    PubMed Central

    Wei, Quan; Zhang, Feng; Richardson, Mekel M.; Roy, Nathan H.; Rodgers, William; Liu, Yuechueng; Zhao, Wenyuan; Fu, Chenying; Ding, Yingjun; Huang, Chao; Chen, Yuanjian; Sun, Yao; Ding, Lexi; Hu, Yang; Ma, Jianxing; Boulton, Michael E.; Pasula, Satish; Wren, Jonathan D.; Tanaka, Satoshi; Huang, Xiaolin; Thali, Markus; Hämmerling, Günter J.; Zhang, Xin A.

    2014-01-01

    Background Angiogenesis is crucial for many pathological processes and becomes a therapeutic strategy against diseases ranging from inflammation to cancer. The regulatory mechanism of angiogenesis remains unclear. Although tetraspanin CD82 is widely expressed in various endothelial cells (ECs), its vascular function is unknown. Methods and Results Angiogenesis was examined in Cd82-null mice with in vivo and ex vivo morphogenesis assays. Cellular functions, molecular interactions, and signaling were analyzed in Cd82-null ECs. Angiogenic responses to various stimuli became markedly increased upon Cd82 ablation. Major changes of Cd82-null ECs were enhanced migration and invasion, likely resulting from the upregulated expression of cell adhesion molecules (CAMs) such as CD44 and integrins at the cell surface and subsequently elevated outside-in signaling. Gangliosides, lipid raft clustering, and CD44-membrane microdomain interactions were increased in the plasma membrane of Cd82-null ECs, leading to less clathrin-independent endocytosis and then more surface presence of CD44. Conclusions Our study reveals that CD82 restrains pathological angiogenesis by inhibiting EC movement, lipid raft clustering and CAM trafficking modulate angiogenic potential, and the perturbation of CD82-ganglioside-CD44 signaling attenuates angiogenesis. PMID:25149363

  2. CD44 Antibody Inhibition of Macrophage Phagocytosis Targets Fcγ Receptor- and Complement Receptor 3-Dependent Mechanisms.

    PubMed

    Amash, Alaa; Wang, Lin; Wang, Yawen; Bhakta, Varsha; Fairn, Gregory D; Hou, Ming; Peng, Jun; Sheffield, William P; Lazarus, Alan H

    2016-04-15

    Targeting CD44, a major leukocyte adhesion molecule, using specific Abs has been shown beneficial in several models of autoimmune and inflammatory diseases. The mechanisms contributing to the anti-inflammatory effects of CD44 Abs, however, remain poorly understood. Phagocytosis is a key component of immune system function and can play a pivotal role in autoimmune states where CD44 Abs have shown to be effective. In this study, we show that the well-known anti-inflammatory CD44 Ab IM7 can inhibit murine macrophage phagocytosis of RBCs. We assessed three selected macrophage phagocytic receptor systems: Fcγ receptors (FcγRs), complement receptor 3 (CR3), and dectin-1. Treatment of macrophages with IM7 resulted in significant inhibition of FcγR-mediated phagocytosis of IgG-opsonized RBCs. The inhibition of FcγR-mediated phagocytosis was at an early stage in the phagocytic process involving both inhibition of the binding of the target RBC to the macrophages and postbinding events. This CD44 Ab also inhibited CR3-mediated phagocytosis of C3bi-opsonized RBCs, but it did not affect the phagocytosis of zymosan particles, known to be mediated by the C-type lectin dectin-1. Other CD44 Abs known to have less broad anti-inflammatory activity, including KM114, KM81, and KM201, did not inhibit FcγR-mediated phagocytosis of RBCs. Taken together, these findings demonstrate selective inhibition of FcγR and CR3-mediated phagocytosis by IM7 and suggest that this broadly anti-inflammatory CD44 Ab inhibits these selected macrophage phagocytic pathways. The understanding of the immune-regulatory effects of CD44 Abs is important in the development and optimization of therapeutic strategies for the potential treatment of autoimmune conditions. PMID:26944929

  3. Prognostic significance of CD44V6 expression in osteosarcoma: a meta-analysis.

    PubMed

    Zhang, Yunyuan; Ding, Chunming; Wang, Jing; Sun, Guirong; Cao, Yongxian; Xu, Longqiang; Zhou, Lan; Chen, Xian

    2015-01-01

    Numerous individual studies evaluating the relationship between CD44V6 over-expression and prognostic impact in patients with osteosarcoma (OS) have yielded in conclusive results. This meta-analysis aimed to determine the value of cell adhesion molecule CD44V6 in prognosis of OS by conducting a systematic review and meta-analysis. A comprehensive search was conducted using PubMed (medline), Embase, ISI Web of Knowledge, Springer, the Cochrane Library, Scopus, BioMed Central, ScienceDirect, Wanfang, Weipu, and China National Knowledge Internet (CNKI) databases from inception through May 26, 2015. All available articles written in English or Chinese that investigated the expression of CD44V6 and the prognosis of OS were included. The quantity of the studies was evaluated according to the critical review checklist of the Dutch Cochrane Centre proposed by MOOSE. Finally, a total of eight studies with 486 OS patients were involved and the results indicated that the positive expression of CD44V6 predicts neoplasm metastasis (RR = 1.76, 95 % CI 1.38-2.25, p < 0.00001), and poor survival in OS with the pooled HR of 1.53 (95 % CI 1.25-1.88, p < 0.0001). No significant heterogeneity was observed among all studies. In conclusion, the present meta-analysis and systematic review strongly suggest that CD44V6 over-expression is associated with overall survival rate and metastasis in OS, and may be used as a prognostic biomarker to guide the clinical therapy for OS. PMID:26697855

  4. Aggravation of Allergic Airway Inflammation by Cigarette Smoke in Mice Is CD44-Dependent

    PubMed Central

    Kumar, Smitha; Lanckacker, Ellen; Dentener, Mieke; Bracke, Ken; Provoost, Sharen; De Grove, Katrien; Brusselle, Guy; Wouters, Emiel

    2016-01-01

    Background Although epidemiological studies reveal that cigarette smoke (CS) facilitates the development and exacerbation of allergic asthma, these studies offer limited information on the mechanisms involved. The transmembrane glycoprotein CD44 is involved in cell adhesion and acts as a receptor for hyaluronic acid and osteopontin. We aimed to investigate the role of CD44 in a murine model of CS-facilitated allergic airway inflammation. Methods Wild type (WT) and CD44 knock-out (KO) mice were exposed simultaneously to house dust mite (HDM) extract and CS. Inflammatory cells, hyaluronic acid (HA) and osteopontin (OPN) levels were measured in bronchoalveolar lavage fluid (BALF). Proinflammatory mediators, goblet cell metaplasia and peribronchial eosinophilia were assessed in lung tissue. T-helper (Th) 1, Th2 and Th17 cytokine production was evaluated in mediastinal lymph node cultures. Results In WT mice, combined HDM/CS exposure increased the number of inflammatory cells and the levels of HA and OPN in BALF and Th2 cytokine production in mediastinal lymph nodes compared to control groups exposed to phosphate buffered saline (PBS)/CS, HDM/Air or PBS/Air. Furthermore, HDM/CS exposure significantly increased goblet cell metaplasia, peribronchial eosinophilia and inflammatory mediators in the lung. CD44 KO mice exposed to HDM/CS had significantly fewer inflammatory cells in BALF, an attenuated Th2 cytokine production, as well as decreased goblet cells and peribronchial eosinophils compared to WT mice. In contrast, the levels of inflammatory mediators were similar or higher than in WT mice. Conclusion We demonstrate for the first time that the aggravation of pulmonary inflammation upon combined exposure to allergen and an environmental pollutant is CD44-dependent. Data from this murine model of concomitant exposure to CS and HDM might be of importance for smoking allergic asthmatics. PMID:26999446

  5. Immunohistochemical analysis of CD44s and CD44v6 in endometriosis and adenomyosis : comparison with normal, hyperplastic, and malignant endometrium.

    PubMed

    Lin, Z; Cho, S; Jeong, H; Kim, H; Kim, I

    2001-06-01

    The expression patterns of CD44s and CD44v6 were immunohistochemically compared with those of normal, hyperplastic and malignant endometrium. In normal endometria (n=37), endometrioses (n=46) and adenomyoses (n=20), the surface and glandular epithelial cells were negative for CD44s and CD44v6 in a proliferative pattern and positive in a secretory pattern, whereas the stroma was only positive for CD44s in both proliferative and secretory patterns. The endometrial hyperplasia (4 simple and 9 complex) had the identical patterns with normal proliferative phase of endometrium. Only one case showing complex hyperplasia with atypia was focally positive for CD44s and CD44v6 in glandular epithelia. CD44s and CD44v6 were positive in all endometrial adenocarcinomas (13), except one CD44s-negative case. In summary, the expressions of CD44s and CD44v6 in endometriosis and adenomyosis recapitulated those of normal cyclic endometrium. The expression patterns in endometrial hyperplasia were similar to those in normal proliferative endometrium, whereas the endometrial adenocarcinoma showed abnormal expressions for CD44s and CD44v6. Thus it was considered that the ectopic endometrium in endometriosis and adenomyosis was not aberrant as in endometrial carcinoma on the aspects of immunohistochemical expressions of CD44s and CD44v6. PMID:11410693

  6. Expression of the Hermes-1 (CD44) and ICAM-1 (CD54) molecule on the surface of thyroid cells from patients with Graves' disease.

    PubMed

    Fukazawa, H; Yoshida, K; Ichinohasama, R; Sawai, T; Hiromatsu, Y; Mori, K; Kikuchi, K; Aizawa, Y; Abe, K; Wall, J R

    1993-01-01

    From studies of binding of 51Cr-labeled T cells to human thyroid monolayers, we have postulated the existence of tissue "homing-like" receptors on thyroid cells in patients with Graves' disease (GD). In this study we have investigated whether the CD44 (Hermes-1) protein, well known as a putative human lymphocyte homing receptor, is expressed on thyroid cells in patients with GD, and if so whether its expression is influenced by interferon-gamma (IFN-gamma). Cell surface CD44, as well as CD54 (ICAM-1), another putative homing receptor, antigens were analyzed by flow cytometry and immunohistochemistry. CD44 and CD54 were both expressed on thyroid cells from untreated patients with GD, which, in the case of CD44, appeared as two peaks. IFN-gamma treatment enhanced the expression of the CD54 protein on Graves' thyroid cells and inhibited the expression of the larger of the two CD44 peaks, but not the other. Only small amounts of CD44 and CD54 were detected on normal thyroid cells, neither of which was affected by IFN-gamma. The CD44 protein was also demonstrated on both GD and normal thyroid cells by immunohistochemistry. These findings suggest that CD44, and possibly CD54, may induce putative adhesion pathways that lead to the homing of lymphocytes to the thyroid in patients who develop Hashimoto's thyroiditis and Graves' disease. PMID:7509669

  7. Overexpression of CD44 accompanies acquired tamoxifen resistance in MCF7 cells and augments their sensitivity to the stromal factors, heregulin and hyaluronan

    PubMed Central

    2012-01-01

    Background Acquired resistance to endocrine therapy in breast cancer is a significant problem with relapse being associated with local and/or regional recurrence and frequent distant metastases. Breast cancer cell models reveal that endocrine resistance is accompanied by a gain in aggressive behaviour driven in part through altered growth factor receptor signalling, particularly involving erbB family receptors. Recently we identified that CD44, a transmembrane cell adhesion receptor known to interact with growth factor receptors, is upregulated in tamoxifen-resistant (TamR) MCF7 breast cancer cells. The purpose of this study was to explore the consequences of CD44 upregulation in an MCF7 cell model of acquired tamoxifen resistance, specifically with respect to the hypothesis that CD44 may influence erbB activity to promote an adverse phenotype. Methods CD44 expression in MCF7 and TamR cells was assessed by RT-PCR, Western blotting and immunocytochemistry. Immunofluorescence and immunoprecipitation studies revealed CD44-erbB associations. TamR cells (± siRNA-mediated CD44 suppression) or MCF7 cells (± transfection with the CD44 gene) were treated with the CD44 ligand, hyaluronon (HA), or heregulin and their in vitro growth (MTT), migration (Boyden chamber and wound healing) and invasion (Matrigel transwell migration) determined. erbB signalling was assessed using Western blotting. The effect of HA on erbB family dimerisation in TamR cells was determined by immunoprecipitation in the presence or absence of CD44 siRNA. Results TamR cells overexpressed CD44 where it was seen to associate with erbB2 at the cell surface. siRNA-mediated suppression of CD44 in TamR cells significantly attenuated their response to heregulin, inhibiting heregulin-induced cell migration and invasion. Furthermore, TamR cells exhibited enhanced sensitivity to HA, with HA treatment resulting in modulation of erbB dimerisation, ligand-independent activation of erbB2 and EGFR and induction

  8. Osteoactivin inhibition of osteoclastogenesis is mediated through CD44-ERK signaling.

    PubMed

    Sondag, Gregory R; Mbimba, Thomas S; Moussa, Fouad M; Novak, Kimberly; Yu, Bing; Jaber, Fatima A; Abdelmagid, Samir M; Geldenhuys, Werner J; Safadi, Fayez F

    2016-01-01

    Osteoactivin is a heavily glycosylated protein shown to have a role in bone remodeling. Previous studies from our lab have shown that mutation in Osteoactivin enhances osteoclast differentiation but inhibits their function. To date, a classical receptor and a signaling pathway for Osteoactivin-mediated osteoclast inhibition has not yet been characterized. In this study, we examined the role of Osteoactivin treatment on osteoclastogenesis using bone marrow-derived osteoclast progenitor cells and identify a signaling pathway relating to Osteoactivin function. We reveal that recombinant Osteoactivin treatment inhibited osteoclast differentiation in a dose-dependent manner shown by qPCR, TRAP staining, activity and count. Using several approaches, we show that Osteoactivin binds CD44 in osteoclasts. Furthermore, recombinant Osteoactivin treatment inhibited ERK phosphorylation in a CD44-dependent manner. Finally, we examined the role of Osteoactivin on receptor activator of nuclear factor-κ B ligand (RANKL)-induced osteolysis in vivo. Our data indicate that recombinant Osteoactivin inhibits RANKL-induced osteolysis in vivo and this effect is CD44-dependent. Overall, our data indicate that Osteoactivin is a negative regulator of osteoclastogenesis in vitro and in vivo and that this process is regulated through CD44 and ERK activation. PMID:27585719

  9. [Serum soluble CD44 isoform variant 5 level in patients with seropositive rheumatoid arthritis treated with cyclosporin A].

    PubMed

    Feyertag, J; Haberhauer, G; Skoumal, M; Kittl, E M; Bauer, K; Dunky, A

    2000-01-01

    CD44 is a widely expressed cell surface glycoprotein which is involved in many cell-cell and cell-matrix interactions. Expression of soluble CD44 splice variants is strictly regulated and is linked to a high rate of cell division. Serum levels of soluble CD44 variant 5 (sCD44v5) were determined in 14 patients with erosive RA. Patients were divided into two groups. In group 1 cyclosporin A treatment (CYA) was initiated after the first visit. In group 2 preliminary CYA was continued. Controls were performed after 6 months. We found a significant decrease of swollen joint count (SJC) and sCD44v5 in group 1. No effect of CYA was found on c-reactive protein, erythrocyte sedimentation rate and IgM-rheumatoid factor (IgM-RF). In group 2 a significant decrease of CRP was found. Therefore we conclude that measurement of sCD44v5 might be useful in monitoring RA+ patients with CYA. PMID:11261266

  10. Silibinin suppresses EGFR ligand-induced CD44 expression through inhibition of EGFR activity in breast cancer cells.

    PubMed

    Kim, Sangmin; Han, Jeonghun; Kim, Jee Soo; Kim, Jung-Han; Choe, Jun-Ho; Yang, Jung-Hyun; Nam, Seok Jin; Lee, Jeong Eon

    2011-11-01

    CD44, the transmembrane receptor for hyaluronan, is implicated in tumor cell invasion and metastasis. The expression of CD44 and its variants is associated with poor prognosis in breast cancer. Here, we investigated the effect of silibinin (a polyphenolic flavonolignan of the herbal plant of Silybum marianum, milk thistle) on the epidermal growth factor (EGF) ligand-induced CD44 expression in human breast cancer cells. The levels of CD44 mRNA and protein expression were greatly increased by EGF and by TGF-α in SKBR3 and BT474 breast cancer cells. In contrast, EGFR ligand-induced CD44 expression was reduced by EGFR inhibitors, AG1478 and lapatinib, respectively. Interestingly, we observed that EGFR ligand-induced CD44 and matrix metalloproteinase-9 (MMP-9) expression was reduced by silibinin treatment in a dose-dependent manner. In addition, silibinin suppressed the EGF-induced phosphorylation of EGFR and extracellular signal-regulated kinase1/2 (ERK1/2), a downstream signaling molecule of EGFR. Therefore, we suggest that silibinin prevents the EGFR signaling pathway and may be used as an effective drug for the inhibition of metastasis of human breast cancer. PMID:22110198

  11. Focal Adhesion Kinase-Dependent Regulation of Adhesive Force Involves Vinculin Recruitment to Focal Adhesions

    PubMed Central

    Hanks, Steven K.; García, Andrés J.

    2016-01-01

    Background information Focal adhesion kinase (FAK), an essential non-receptor tyrosine kinase, plays pivotal roles in migratory responses, adhesive signaling, and mechanotransduction. FAK-dependent regulation of cell migration involves focal adhesion turnover dynamics as well as actin cytoskeleton polymerization and lamellipodia protrusion. Whereas roles for FAK in migratory and mechanosensing responses have been established, the contributions of FAK to the generation of adhesive forces are not well understood. Results Using FAK-null cells expressing wild-type and mutant FAK under an inducible tetracycline promoter, we analyzed the role of FAK in the generation of steady-state adhesive forces using micropatterned substrates and a hydrodynamic adhesion assay. FAK expression reduced steady-state strength by 30% compared to FAK-null cells. FAK expression reduced vinculin localization to focal adhesions by 35% independently from changes in integrin binding and localization of talin and paxillin. RNAi knockdown of vinculin abrogated the FAK-dependent differences in adhesive force. FAK-dependent changes in vinculin localization and adhesive force were confirmed in human primary fibroblasts with FAK knocked down by RNAi. The autophosphorylation Y397 and kinase domain Y576/Y577 sites were differentially required for FAK-mediated adhesive responses. Conclusions We demonstrate that FAK reduces steady-state adhesion strength by modulating vinculin recruitment to focal adhesions. These findings provide insights into the role of FAK in mechanical interactions between a cell and the extracellular matrix. PMID:19883375

  12. CD44 and HCELL: Preventing Hematogenous Metastasis at Step 1

    PubMed Central

    Jacobs, Pieter P.; Sackstein, Robert

    2011-01-01

    Despite great strides in our knowledge of the genetic and epigenetic changes underlying malignancy, we have limited information on the molecular basis of metastasis. Over 90% of cancer deaths are caused by spread of tumor cells from a primary site to distant organs and tissues, highlighting the pressing need to define the molecular effectors of cancer metastasis. Mounting evidence suggests that circulating tumor cells home to specific tissues by hijacking the normal leukocyte trafficking mechanisms. Cancer cells characteristically express CD44, and there is increasing evidence that HCELL, a sialofucosylated glycoform of CD44, serves as the major selectin ligand on cancer cells, allowing interaction of tumor cells with endothelium, leukocytes, and platelets. Here, we review the structural biology of CD44 and of HCELL, and present current data on the function of these molecules in mediating organ-specific homing/metastasis of circulating tumor cells. PMID:21827751

  13. Anti-CD44-mediated blockade of leukocyte migration in skin-associated immune diseases.

    PubMed

    Zöller, Margot; Gupta, Pooja; Marhaba, Rachid; Vitacolonna, Mario; Freyschmidt-Paul, Pia

    2007-07-01

    CD44 plays an important role in leukocyte extravasation, which is fortified in autoimmune diseases and delayed-type hypersensitivity (DTH) reactions. There is additional evidence that distinct CD44 isoforms interfere with the extravasation of selective leukocyte subsets. We wanted to explore this question in alopecia areata (AA), a hair-follicle centric autoimmune disease, and in a chronic eczema. The question became of interest because AA is treated efficiently by topical application of a contact sensitizer, such that a mild DTH reaction is maintained persistently. Aiming to support the therapeutic efficacy of a chronic eczema in AA by anti-CD44 treatment, it became essential to control whether a blockade of migration, preferentially of AA effector cells, could be achieved by CD44 isoform-specific antibodies. Anti-panCD44 and anti-CD44 variant 10 isoform (CD44v10) inhibited in vitro migration of leukocytes from untreated and allergen-treated, control and AA mice. In vivo, both antibodies interfered with T cell and monocyte extravasation into the skin; only anti-panCD44 prevented T cell homing into lymph nodes. Contributing factors are disease-dependent alterations in chemokine/chemokine receptor expression and a blockade of CD44 on endothelial cells and leukocytes. It is important that CD44 can associate with several integrins and ICAM-1. Associations depend on CD44 activation and vary with CD44 isoforms and leukocyte subpopulations. CD44 standard isoform preferentially associates with CD49d in T cells and CD44v10 with CD11b in monocytes. Accordingly, anti-panCD44 and anti-CD49d inhibit T cell, anti-CD11b, and anti-CD44v10 macrophage migration most efficiently. Thus, allergen treatment of AA likely can be supported by targeting AA T cells selectively via a panCD44-CD49d-bispecific antibody. PMID:17442857

  14. Challenging the roles of CD44 and lipolysis stimulated lipoprotein receptor in conveying Clostridium perfringens iota toxin cytotoxicity in breast cancer

    PubMed Central

    2014-01-01

    Background Translational exploration of bacterial toxins has come to the forefront of research given their potential as a chemotherapeutic tool. Studies in select tissues have demonstrated that Clostridium perfringens iota toxin binds to CD44 and lipolysis stimulated lipoprotein receptor (LSR) cell-surface proteins. We recently demonstrated that LSR expression correlates with estrogen receptor positive breast cancers and that LSR signaling directs aggressive, tumor-initiating cell behaviors. Herein, we identify the mechanisms of iota toxin cytotoxicity in a tissue-specific, breast cancer model with the ultimate goal of laying the foundation for using iota toxin as a targeted breast cancer therapy. Methods In vitro model systems were used to determine the cytotoxic effect of iota toxin on breast cancer intrinsic subtypes. The use of overexpression and knockdown technologies confirmed the roles of LSR and CD44 in regulating iota toxin endocytosis and induction of cell death. Lastly, cytotoxicity assays were used to demonstrate the effect of iota toxin on a validated set of tamoxifen resistant breast cancer cell lines. Results Treatment of 14 breast cancer cell lines revealed that LSR+/CD44- lines were highly sensitive, LSR+/CD44+ lines were slightly sensitive, and LSR-/CD44+ lines were resistant to iota cytotoxicity. Reduction in LSR expression resulted in a significant decrease in toxin sensitivity; however, overexpression of CD44 conveyed toxin resistance. CD44 overexpression was correlated with decreased toxin-stimulated lysosome formation and decreased cytosolic levels of iota toxin. These findings indicated that expression of CD44 drives iota toxin resistance through inhibition of endocytosis in breast cancer cells, a role not previously defined for CD44. Moreover, tamoxifen-resistant breast cancer cells exhibited robust expression of LSR and were highly sensitive to iota-induced cytotoxicity. Conclusions Collectively, these data are the first to show that iota

  15. sCD44 overexpression increases intraocular pressure and aqueous outflow resistance

    PubMed Central

    Giovingo, Michael; Nolan, Michael; McCarty, Ryan; Pang, Iok-Hou; Clark, Abbot F.; Beverley, Rachel M.; Schwartz, Steven; Stamer, W. Daniel; Walker, Loyal; Grybauskas, Algis; Skuran, Kevin; Kuprys, Paulius V.; Yue, Beatrice Y.J.T.

    2013-01-01

    Purpose CD44 plays major roles in multiple physiologic processes. The ectodomain concentration of the CD44 receptor, soluble CD44 (sCD44), is significantly increased in the aqueous humor of primary open-angle glaucoma (POAG). The purpose of this study was to determine if adenoviral constructs of CD44 and isolated 32-kDa sCD44 change intraocular pressure (IOP) in vivo and aqueous outflow resistance in vitro. Methods Adenoviral constructs of human standard CD44 (Ad-CD44S), soluble CD44 (Ad-sCD44), and empty viral cDNA were injected into the vitreous of BALB/cJ mice, followed by serial IOP measurements. Overexpression of CD44S and sCD44 was verified in vitro by enzyme-linked immunosorbent assay (ELISA) and western blot analysis. Anterior segments of porcine eyes were perfused with the isolated sCD44. sCD44-treated human trabecular meshwork (TM) cells and microdissected porcine TM were examined by confocal microscopy and Optiprep density gradient with western blot analysis to determine changes in lipid raft components. Results Intravitreous injection of adenoviral constructs with either Ad-CD44S or Ad-sCD44 vectors caused prolonged ocular hypertension in mice. Eight days after vector injection, Ad-CD44S significantly elevated IOP to 28.3±1.2 mmHg (mean±SEM, n=8; p<0.001); Ad-sCD44 increased IOP to 18.5±2.6 mmHg (n=8; p<0.01), whereas the IOP of uninjected eyes was 12.7±0.2 mmHg (n=16). The IOP elevation lasted more than 50 days. Topical administration of a γ-secretase inhibitor normalized Ad-sCD44-induced elevated IOP. sCD44 levels were significantly elevated in the aqueous humor of Ad-CD44S and Ad-sCD44 eyes versus contralateral uninjected eyes (p<0.01). Anterior segment perfusion of isolated 32-kDa sCD44 significantly decreased aqueous outflow rates. Co-administration of isolated sCD44 and CD44 neutralizing antibody or of γ-secretase inhibitor significantly enhanced flow rates. sCD44-treated human TM cells displayed cross-linked actin network formation

  16. CD44/chondroitin sulfate proteoglycan and alpha 2 beta 1 integrin mediate human melanoma cell migration on type IV collagen and invasion of basement membranes.

    PubMed Central

    Knutson, J R; Iida, J; Fields, G B; McCarthy, J B

    1996-01-01

    Tumor cell invasion of basement membranes (BM) represents one of the critical steps in the metastatic process. Tumor cell recognition of individual BM matrix components may involve individual cell adhesion receptors, such as integrins or cell surface proteoglycans, or may involve a coordinate action of both types of receptors. In this study, we have focused on the identification of a cell surface CD44/chondroitin sulfate proteoglycan (CSPG) and alpha 2 beta 1 integrin on human melanoma cells that are both directly involved in the in vitro invasion of reconstituted BM via a type IV collagen-dependent mechanism. Interfering with cell surface expression of human melanoma CSPG with either p-nitro-phenyl-beta-D-xylopyranoside treatment or anti-CD44 monoclonal antibody (mAb) preincubation (mAb) preincubation inhibits melanoma cell invasion through reconstituted BM. These treatments also strongly inhibit melanoma cell migration on type IV collagen, however, they are ineffective at inhibiting cell adhesion to type IV collagen. Purified melanoma cell surface CD44/CSPG, or purified chondroitin sulfate, bind to type IV collagen affinity columns, consistent with a role for CD44/CSPG-type IV collagen interactions in mediating tumor cell invasion. In contrast, melanoma cell migration on laminin (LM) does not involve CD44/CSPG, nor does CD44/CSPG bind to LM, suggesting that CD44/CSPG-type IV collagen interactions are specific in nature. Additionally, anti-alpha 2 and anti-beta 1 integrin mAbs are capable of blocking melanoma cell invasion of reconstituted BM. Both of these anti-integrin mAbs inhibit melanoma cell adhesion and migration on type IV collagen, whereas only anti-beta 1 mAb inhibits cell adhesion to LM. Collectively, these results indicate that melanoma cell adhesion to type IV collagen is an important consideration in invasion of reconstituted BM in vitro, and suggest that CD44/CSPG and alpha 2 beta 1 integrin may collaborate to promote human melanoma cell adhesion

  17. Temporal variation in the distribution of hyaluronic acid, CD44s, and CD44v6 in the human endometrium across the menstrual cycle.

    PubMed

    Afify, Alaa M; Craig, Sarah; Paulino, Augusto F G

    2006-09-01

    Tissues undergoing rapid growth and regeneration contain hyaluronic acid (HA) as a prominent component of the extracellular matrix. The physiologic role of HA is partly mediated by its relationship with CD44, its major cell surface receptor. Given the extensive remodeling of the endometrium during the menstrual cycle, the authors sought to determine whether these changes are related to the levels of HA, CD44s, and CD44v6 in the endometrium. Archival paraffin embedded cell blocks from 10 cases of proliferative endometrium and 20 cases of secretory endometrium were retrieved from the surgical pathology files. Specimens from the secretory phase were subdivided into three categories: early secretory (day 15-18), mid-secretory (day 19-23), and late secretory (day 24-28). All cases were stained for hyaluronic acid, CD44s, and CD44v6. Sections from umbilical cord, tonsil, and squamous cell carcinoma served as positive controls for HA, CD44s, and CD44v6, respectively. Positive staining was defined as droplet to diffuse intracytoplasmic or extracellular staining for HA and uniform membranous staining for CD44. During the proliferative phase, the endometrial glands and the stroma were both negative for CD44s and CD44v6 in all cases. In the secretory phase, the endometrial glands were negative for CD44s in all cases, but CD44v6 was expressed in 12 (60%) of cases. In contrast, the stromal cells expressed CD44s in 18 (90%) cases and were negative for CD44v6 in all cases. HA staining was present in the endometrial stroma throughout the menstrual cycle but was most intense (3+) and diffuse during the midsecretory phase. There was perivascular staining for HA throughout the cycle; it was most intense adjacent to the spiral arterioles in the secretory phase. These data indicate temporal and geographic differences in HA and CD44 staining in the endometrium in concert with the menstrual cycle. The timing of peak staining of HA and CD44s in the stroma and the upregulation of CD44v6 in

  18. The role of CD44 in epithelial–mesenchymal transition and cancer development

    PubMed Central

    Xu, Hanxiao; Tian, Yijun; Yuan, Xun; Wu, Hua; Liu, Qian; Pestell, Richard G; Wu, Kongming

    2015-01-01

    CD44, a multi-structural and multifunctional transmembrane glycoprotein, was initially identified as a receptor for hyaluronan that participates in both physiological and pathological processes. CD44 is found to be closely linked to the development of various solid tumors. Molecular studies have revealed that high CD44 expression was correlated with the phenotypes of cancer stem cells and epithelial–mesenchymal transition, thereby contributing to tumor invasion, metastasis, recurrence, and chemoresistance. Correspondingly, blockade of CD44 has been demonstrated to be capable of attenuating the malignant phenotype, slowing cancer progression, and reversing therapy resistance. Clinical analyses showed that high CD44 expression is associated with poor survival of various cancer patients, indicating that CD44 can be a potential prognostic marker. In this review, we summarize recent research progress of CD44 on tumor biology and the clinical significance of CD44. PMID:26719706

  19. Hyaluronan-CD44 Interaction Promotes Growth of Decidual Stromal Cells in Human First-Trimester Pregnancy

    PubMed Central

    Zhu, Rui; Wang, Song-Cun; Sun, Chan; Tao, Yu; Piao, Hai-Lan; Wang, Xiao-Qiu; Du, Mei-Rong; Da-Jin Li

    2013-01-01

    Hyaluronan (HA) and its receptor CD44 are expressed at the maternal-fetal interface, but its role in early pregnancy remains unclear. Here, we found that primary decidual stromal cells (DSCs) continuously secreted HA and expressed its receptor CD44. Pregnancy-associated hormones up-regulated HA synthetase (HAS) 2 transcription and HA release from DSCs. High molecular weight-HA (HMW-HA), but not medium molecular weight (MMW-HA) or low molecular weight (LMW-HA), promoted proliferation and inhibited apoptosis of DSCs in a CD44-dependent manner. The in-cell Western analysis revealed HMW-HA activated PI3K/AKT and mitogen-activated protein kinase (MAPK)/ERK1/2 signaling pathways time-dependently. Blocking these pathways by specific inhibitor LY294002 or U0126 abrogated HMW-HA-regulated DSc proliferation and apoptosis. Finally, we have found that HA content, HA molecular weight, HAS2 mRNA level, and CD44 expression were significantly decreased in DSCs from unexplained miscarriage compared with the normal pregnancy. Collectively, our results indicate that higher level and greater molecular mass of HA at maternal-fetal interface contributes to DSc growth and maintenance of DSCs in human early pregnancy. PMID:24069351

  20. Hyaluronan-CD44 interaction promotes growth of decidual stromal cells in human first-trimester pregnancy.

    PubMed

    Zhu, Rui; Wang, Song-Cun; Sun, Chan; Tao, Yu; Piao, Hai-Lan; Wang, Xiao-Qiu; Du, Mei-Rong; Da-Jin Li

    2013-01-01

    Hyaluronan (HA) and its receptor CD44 are expressed at the maternal-fetal interface, but its role in early pregnancy remains unclear. Here, we found that primary decidual stromal cells (DSCs) continuously secreted HA and expressed its receptor CD44. Pregnancy-associated hormones up-regulated HA synthetase (HAS) 2 transcription and HA release from DSCs. High molecular weight-HA (HMW-HA), but not medium molecular weight (MMW-HA) or low molecular weight (LMW-HA), promoted proliferation and inhibited apoptosis of DSCs in a CD44-dependent manner. The in-cell Western analysis revealed HMW-HA activated PI3K/AKT and mitogen-activated protein kinase (MAPK)/ERK1/2 signaling pathways time-dependently. Blocking these pathways by specific inhibitor LY294002 or U0126 abrogated HMW-HA-regulated DSc proliferation and apoptosis. Finally, we have found that HA content, HA molecular weight, HAS2 mRNA level, and CD44 expression were significantly decreased in DSCs from unexplained miscarriage compared with the normal pregnancy. Collectively, our results indicate that higher level and greater molecular mass of HA at maternal-fetal interface contributes to DSc growth and maintenance of DSCs in human early pregnancy. PMID:24069351

  1. Immunohistochemical expression of CD44s in human neuroblastic tumors: Moroccan experience and highlights on current data

    PubMed Central

    2013-01-01

    Background Peripheral neuroblastic tumors (pNTs), including neuroblastoma (NB), ganglioneuroblastoma (GNB) and ganglioneuroma (GN), are extremely heterogeneous pediatric tumors responsible for 15 % of childhood cancer death. The aim of the study was to evaluate the expression of CD44s (‘s’: standard form) cell adhesion molecule by comparison with other specific prognostic markers. Methods An immunohistochemical profile of 32 formalin-fixed paraffin-embedded pNTs tissues, diagnosed between January 2007 and December 2010, was carried out. Results Our results have demonstrated the association of CD44s negative pNTs cells to lack of differentiation and tumour progression. A significant association between absence of CD44s expression and metastasis in human pNTs has been reported. We also found that expression of CD44s defines subgroups of patients without MYCN amplification as evidenced by its association with low INSS stages, absence of metastasis and favorable Shimada histology. Discussion These findings support the thesis of the role of CD44s glycoprotein in the invasive growth potential of neoplastic cells and suggest that its expression could be taken into consideration in the therapeutic approaches targeting metastases. Virtual Slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1034403150888863 Résumé Introduction les tumeurs neuroblastiques périphériques (TNPs), comprenant le neuroblastome (NB), le ganglioneuroblastome (GNB) et le ganglioneurome (GN), sont des tumeurs pédiatriques extrêmement hétérogènes responsables de 15% des décès par cancer chez les enfants. Le but de cette étude était d’évaluer l’expression de la molécule d’adhésion cellulaire CD44s (‘s’: pour standard) par rapport à d’autres facteurs pronostiques spécifiques. Méthodes Un profil immunohistochimique de 32 TNPs fixées au formol et incluses en paraffine, diagnostiquées entre Janvier 2007 et D

  2. Multifunctionalized iron oxide nanoparticles for selective drug delivery to CD44-positive cancer cells.

    PubMed

    Aires, Antonio; Ocampo, Sandra M; Simões, Bruno M; Josefa Rodríguez, María; Cadenas, Jael F; Couleaud, Pierre; Spence, Katherine; Latorre, Alfonso; Miranda, Rodolfo; Somoza, Álvaro; Clarke, Robert B; Carrascosa, José L; Cortajarena, Aitziber L

    2016-02-12

    Nanomedicine nowadays offers novel solutions in cancer therapy and diagnosis by introducing multimodal treatments and imaging tools in one single formulation. Nanoparticles acting as nanocarriers change the solubility, biodistribution and efficiency of therapeutic molecules, reducing their side effects. In order to successfully  apply these novel therapeutic approaches, efforts are focused on the biological functionalization of the nanoparticles to improve the selectivity towards cancer cells. In this work, we present the synthesis and characterization of novel multifunctionalized iron oxide magnetic nanoparticles (MNPs) with antiCD44 antibody and gemcitabine derivatives, and their application for the selective treatment of CD44-positive cancer cells. The lymphocyte homing receptor CD44 is overexpressed in a large variety of cancer cells, but also in cancer stem cells (CSCs) and circulating tumor cells (CTCs). Therefore, targeting CD44-overexpressing cells is a challenging and promising anticancer strategy. Firstly, we demonstrate the targeting of antiCD44 functionalized MNPs to different CD44-positive cancer cell lines using a CD44-negative non-tumorigenic cell line as a control, and verify the specificity by ultrastructural characterization and downregulation of CD44 expression. Finally, we show the selective drug delivery potential of the MNPs by the killing of CD44-positive cancer cells using a CD44-negative non-tumorigenic cell line as a control. In conclusion, the proposed multifunctionalized MNPs represent an excellent biocompatible nanoplatform for selective CD44-positive cancer therapy in vitro. PMID:26754042

  3. Differential CD44 expression patterns in primary brain tumours and brain metastases.

    PubMed Central

    Li, H.; Liu, J.; Hofmann, M.; Hamou, M. F.; de Tribolet, N.

    1995-01-01

    Splicing variants of CD44 (CD44v) are increasingly recognised as metastasis-promoting factors in rodent and some human cancers. However, the frequency for CD44v expression in human cancers and their metastases and the status of CD44v expression in low or non-metastatic tumours is still uncertain. To address this issue, we investigated CD44 expression patterns in brain metastases (BMTs) spread from more than ten organs and five types of primary brain tumours (PBTs) by Northern blot, reverse transcription-polymerase chain reaction (RT-PCR) and immunocytochemical analysis. The results demonstrated that all of the 56 PBTs examined express standard form of CD44 (CD44s) but none of them express CD44v. In contrast, 22 of 26 BMTs studied were found with CD44v expression. Our data thus present direct evidence of a general distribution of CD44 in BMTs but suggest that such expression is an extremely rare event in PBTs. Therefore, the presence or absence of CD44v expression may be related to high or low metastatic potential of human malignancies. Images Figure 2 Figure 1 PMID:7541233

  4. Multifunctionalized iron oxide nanoparticles for selective drug delivery to CD44-positive cancer cells

    NASA Astrophysics Data System (ADS)

    Aires, Antonio; Ocampo, Sandra M.; Simões, Bruno M.; Josefa Rodríguez, María; Cadenas, Jael F.; Couleaud, Pierre; Spence, Katherine; Latorre, Alfonso; Miranda, Rodolfo; Somoza, Álvaro; Clarke, Robert B.; Carrascosa, José L.; Cortajarena, Aitziber L.

    2016-02-01

    Nanomedicine nowadays offers novel solutions in cancer therapy and diagnosis by introducing multimodal treatments and imaging tools in one single formulation. Nanoparticles acting as nanocarriers change the solubility, biodistribution and efficiency of therapeutic molecules, reducing their side effects. In order to successfully apply these novel therapeutic approaches, efforts are focused on the biological functionalization of the nanoparticles to improve the selectivity towards cancer cells. In this work, we present the synthesis and characterization of novel multifunctionalized iron oxide magnetic nanoparticles (MNPs) with antiCD44 antibody and gemcitabine derivatives, and their application for the selective treatment of CD44-positive cancer cells. The lymphocyte homing receptor CD44 is overexpressed in a large variety of cancer cells, but also in cancer stem cells (CSCs) and circulating tumor cells (CTCs). Therefore, targeting CD44-overexpressing cells is a challenging and promising anticancer strategy. Firstly, we demonstrate the targeting of antiCD44 functionalized MNPs to different CD44-positive cancer cell lines using a CD44-negative non-tumorigenic cell line as a control, and verify the specificity by ultrastructural characterization and downregulation of CD44 expression. Finally, we show the selective drug delivery potential of the MNPs by the killing of CD44-positive cancer cells using a CD44-negative non-tumorigenic cell line as a control. In conclusion, the proposed multifunctionalized MNPs represent an excellent biocompatible nanoplatform for selective CD44-positive cancer therapy in vitro.

  5. Direct binding of hepatocyte growth factor and vascular endothelial growth factor to CD44v6

    PubMed Central

    Volz, Yvonne; Koschut, David; Matzke-Ogi, Alexandra; Dietz, Marina S.; Karathanasis, Christos; Richert, Ludovic; Wagner, Moritz G.; Mély, Yves; Heilemann, Mike; Niemann, Hartmut H.; Orian-Rousseau, Véronique

    2015-01-01

    CD44v6, a member of the CD44 family of transmembrane glycoproteins is a co-receptor for two receptor tyrosine kinases (RTKs), Met and VEGFR-2 (vascular endothelial growth factor receptor 2). CD44v6 is not only required for the activation of these RTKs but also for signalling. In order to understand the role of CD44v6 in Met and VEGFR-2 activation and signalling we tested whether CD44v6 binds to their ligands, HGF (hepatocyte growth factor) and VEGF (vascular endothelial growth factor), respectively. FACS analysis and cellular ELISA showed binding of HGF and VEGF only to cells expressing CD44v6. Direct binding of CD44v6 to HGF and VEGF was demonstrated in pull-down assays and the binding affinities were determined using MicroScale Thermophoresis, fluorescence correlation spectroscopy and fluorescence anisotropy. The binding affinity of CD44v6 to HGF is in the micromolar range in contrast with the high-affinity binding measured in the case of VEGF and CD44v6, which is in the nanomolar range. These data reveal a heparan sulfate-independent direct binding of CD44v6 to the ligands of Met and VEGFR-2 and suggest different roles of CD44v6 for these RTKs. PMID:26181364

  6. Overexpression of molecular chaperons GRP78 and GRP94 in CD44hi/CD24lo breast cancer stem cells

    PubMed Central

    Nami, Babak; Ghasemi-Dizgah, Armin; Vaseghi, Akbar

    2016-01-01

    Introduction: Breast cancer stem cell with CD44hi/CD24lo phonotype is described having stem cell properties and represented as the main driving factor in breast cancer initiation, growth, metastasis and low response to anti-cancer agents. Glucoseregulated proteins (GRPs) are heat shock protein family chaperons that are charged with regulation of protein machinery and modulation of endoplasmic reticulum homeostasis whose important roles in stem cell development and invasion of various cancers have been demonstrated. Here, we investigated the expression levels of GRP78 and GRP94 in CD44hi/CD24lo phenotype breast cancer stem cells (BCSCs). Methods: MCF7, T-47D and MDA-MB-231 breast cancer cell lines were used. CD44hi/CD24lo phenotype cell population were analyzed and sorted by fluorescence-activated cell sorting (FACS). Transcriptional and translational expression of GRP78 and GRP94 were investigated by western blotting and quantitative real time PCR. Results: Results showed different proportion of CD44hi/CD24lo phenotype cell population in their original bulk cells. The ranking of the cell lines in terms of CD44hi/CD24lo phenotype cell population was as MCF7CD44hi/CD24lo phenotype cells exhibited higher mRNA and protein expression level of GRP78 and GRP94 compared to their original bulk cells. Conclusion: Our results show a relationship between overexpression of GRP78 and GRP94 and exhibiting CD44hi/CD24lo phenotype in breast cancer cells. We conclude that upregulation of GRPs may be an important factor in the emergence of CD44hi/CD24lo phenotype BCSCs features. PMID:27525228

  7. Radiation-Induced Reprogramming of Pre-Senescent Mammary Epithelial Cells Enriches Putative CD44+/CD24−/low Stem Cell Phenotype

    PubMed Central

    Gao, Xuefeng; Sishc, Brock J.; Nelson, Christopher B.; Hahnfeldt, Philip; Bailey, Susan M.; Hlatky, Lynn

    2016-01-01

    The enrichment of putative CD44+/CD24−/low breast stem cell populations following exposure to ionizing radiation (IR) has been ascribed to their inherent radioresistance and an elevated frequency of symmetric division during repopulation. However, recent studies demonstrating radiation-induced phenotypic reprogramming (the transition of non-CD44+/CD24−/low cells into the CD44+/CD24−/low phenotype) as a potential mechanism of CD44+/CD24−/low cell enrichment have raised the question of whether a higher survival and increased self-renewal of existing CD44+/CD24−/low cells or induced reprogramming is an additional mode of enrichment. To investigate this question, we combined a cellular automata model with in vitro experimental data using both MCF-10A non-tumorigenic human mammary epithelial cells and MCF-7 breast cancer cells, with the goal of identifying the mechanistic basis of CD44+/CD24−/low stem cell enrichment in the context of radiation-induced cellular senescence. Quantitative modeling revealed that incomplete phenotypic reprogramming of pre-senescent non-stem cells (reprogramming whereby the CD44+/CD24−/low phenotype is conveyed, along with the short-term proliferation capacity of the original cell) could be an additional mode of enriching the CD44+/CD24−/low subpopulation. Furthermore, stem cell enrichment in MCF-7 cells occurs both at lower doses and earlier time points, and has longer persistence, than that observed in MCF-10A cells, suggesting that phenotypic plasticity appears to be less regulated in breast cancer cells. Taken together, these results suggest that reprogramming of pre-senescent non-stem cells may play a significant role in both cancer and non-tumorigenic mammary epithelial populations following exposure to IR, a finding with important implications for both radiation therapy and radiation carcinogenesis. PMID:27379202

  8. Selective killing of breast cancer cells expressing activated CD44 using CD44 ligand-coated nanoparticles in vitro and in vivo

    PubMed Central

    Zhang, Huizhen; Liu, Yiwen; Wang, Wenjuan; Du, Yan; Gao, Feng

    2015-01-01

    The cell surface glycoprotein CD44 is expressed in cancer cells and has been used as a therapeutic target in preclinical studies. However, the ubiquitous expression of CD44 in numerous cell types, including hematopoietic cells, has hindered its application in targeted therapy. Here, we demonstrated that CD44 was activated on breast cancer cells but was inactive on normal cells in vitro and in vivo. We analyzed 34 clinical primary tumor and normal breast tissues and demonstrated that CD44 was in an active state on breast cancer cells but in an inactive state on normal cells. Furthermore, based on the binding property of CD44 with its ligand hyaluronan (HA), we self-assembled HA-coated nanoparticles and studied their selective targeting efficacy. Our results indicate that HA-coated nanoparticles bearing the CD44 ligand selectively targeted cancer cells both in vitro and in vivo, killing breast cancer cells while sparing normal cells. Our study suggested that the active state of CD44 plays a crucial role in the selective targeting of breast cancer cells by avoiding nonspecific toxicity to CD44-quiescent normal cells. These findings may provide a new idea for the selective targeting of cancer cells in other human cancers. PMID:25909172

  9. The Importance of CD44 as a Stem Cell Biomarker and Therapeutic Target in Cancer

    PubMed Central

    Thapa, Ranjeeta; Wilson, George D.

    2016-01-01

    CD44 is a cell surface HA-binding glycoprotein that is overexpressed to some extent by almost all tumors of epithelial origin and plays an important role in tumor initiation and metastasis. CD44 is a compelling marker for cancer stem cells of many solid malignancies. In addition, interaction of HA and CD44 promotes EGFR-mediated pathways, consequently leading to tumor cell growth, tumor cell migration, and chemotherapy resistance in solid cancers. Accumulating evidence indicates that major HA-CD44 signaling pathways involve a specific variant of CD44 isoforms; however, the particular variant almost certainly depends on the type of tumor cell and the stage of the cancer progression. Research to date suggests use of monoclonal antibodies against different CD44 variant isoforms and targeted inhibition of HA/CD44-mediated signaling combined with conventional radio/chemotherapy may be the most favorable therapeutic strategy for future treatments of advanced stage malignancies. Thus, this paper briefly focuses on the association of the major CD44 variant isoforms in cancer progression, the role of HA-CD44 interaction in oncogenic pathways, and strategies to target CD44-overexpressed tumor cells. PMID:27200096

  10. Overexpression of Specific CD44 Isoforms Is Associated with Aggressive Cell Features in Acquired Endocrine Resistance

    PubMed Central

    Bellerby, Rebecca; Smith, Chris; Kyme, Sue; Gee, Julia; Günthert, Ursula; Green, Andy; Rakha, Emad; Barrett-Lee, Peter; Hiscox, Stephen

    2016-01-01

    While endocrine therapy is the mainstay of ER+ breast cancer, the clinical effectiveness of these agents is limited by the phenomenon of acquired resistance that is associated with disease relapse and poor prognosis. Our previous studies revealed that acquired resistance is accompanied by a gain in cellular invasion and migration and also that CD44 family proteins are overexpressed in the resistant phenotype. Given the association of CD44 with tumor progression, we hypothesized that its overexpression may act to promote the aggressive behavior of endocrine-resistant breast cancers. Here, we have investigated further the role of two specific CD44 isoforms, CD44v3 and CD44v6, in the endocrine-resistant phenotype. Our data revealed that overexpression of CD44v6, but not CD44v3, in endocrine-sensitive MCF-7 cells resulted in a gain in EGFR signaling, enhanced their endogenous invasive capacity, and attenuated their response to endocrine treatment. Suppression of CD44v6 in endocrine-resistant cell models was associated with a reduction in their invasive capacity. Our data suggest that upregulation of CD44v6 in acquired resistant breast cancer may contribute to a gain in the aggressive phenotype of these cells and loss of endocrine response through transactivation of the EGFR pathway. Future therapeutic targeting of CD44v6 may prove to be an effective strategy alongside EGFR-targeted agents in delaying/preventing acquired resistance in breast cancer. PMID:27379207

  11. Serum levels of soluble CD44 variant isoforms are elevated in rheumatoid arthritis.

    PubMed

    Kittl, E M; Haberhauer, G; Ruckser, R; Selleny, S; Rech-Weichselbraun, I; Hinterberger, W; Bauer, K

    1997-01-01

    Serum levels of soluble CD44 variant proteins including sequences encoded by exon v5 and exon v6 (sCD44v5, sCD44v6) were determined in patients with inflammatory rheumatic diseases: 56 with rheumatoid arthritis (RA+) and 31 with miscellaneous inflammatory rheumatic diseases (MIRD). There were very significantly higher serum levels of sCD44v5 and sCD44v6 in patients with RA+ than in those with MIRD (RA+ to MIRD: sCD44v5: 81 +/- 54 ng/ml to 33 +/- 13 ng/ml; sCD44v6: 237 +/- 124 ng/ml to 166 +/- 53 ng/ml; both P < 0.001). In RA+ elevated serum levels of sCD44v5 were correlated with the inflammatory activity of disease. In 17 patients with RA+ three or four follow-up measurements of sCD44v5 were performed within 6 months. The development of sCD44v5 serum levels reflected the clinical course of disease in the patients investigated. PMID:9032816

  12. Conservation of CD44 exon v3 functional elements in mammals

    PubMed Central

    Vela, Elena; Hilari, Josep M; Delclaux, María; Fernández-Bellon, Hugo; Isamat, Marcos

    2008-01-01

    Background The human CD44 gene contains 10 variable exons (v1 to v10) that can be alternatively spliced to generate hundreds of different CD44 protein isoforms. Human CD44 variable exon v3 inclusion in the final mRNA depends on a multisite bipartite splicing enhancer located within the exon itself, which we have recently described, and provides the protein domain responsible for growth factor binding to CD44. Findings We have analyzed the sequence of CD44v3 in 95 mammalian species to report high conservation levels for both its splicing regulatory elements (the 3' splice site and the exonic splicing enhancer), and the functional glycosaminglycan binding site coded by v3. We also report the functional expression of CD44v3 isoforms in peripheral blood cells of different mammalian taxa with both consensus and variant v3 sequences. Conclusion CD44v3 mammalian sequences maintain all functional splicing regulatory elements as well as the GAG binding site with the same relative positions and sequence identity previously described during alternative splicing of human CD44. The sequence within the GAG attachment site, which in turn contains the Y motif of the exonic splicing enhancer, is more conserved relative to the rest of exon. Amplification of CD44v3 sequence from mammalian species but not from birds, fish or reptiles, may lead to classify CD44v3 as an exclusive mammalian gene trait. PMID:18710510

  13. Can CD44 Be a Mediator of Cell Destruction? The Challenge of Type 1 Diabetes

    PubMed Central

    Assayag-Asherie, Nathalie; Sever, Dror; Bogdani, Marika; Johnson, Pamela; Weiss, Talya; Ginzberg, Ariel; Perles, Sharon; Weiss, Lola; Sebban, Lora Eshkar; Turley, Eva A.; Okon, Elimelech; Raz, Itamar; Naor, David

    2015-01-01

    CD44 is a multi-functional receptor with multiple of isoforms engaged in modulation of cell trafficking and transmission of apoptotic signals. We have previously shown that injection of anti-CD44 antibody into NOD mice induced resistance to type 1 diabetes (T1D). In this communication we describe our efforts to understand the mechanism underlying this effect. We found that CD44-deficient NOD mice develop stronger resistance to T1D than wild-type littermates. This effect is not explained by the involvement of CD44 in cell migration, because CD44-deficient inflammatory cells surprisingly had greater invasive potential than the corresponding wild type cells, probably owing to molecular redundancy. We have previously reported and we show here again that CD44 expression and hyaluronic acid (HA, the principal ligand for CD44) accumulation are detected in pancreatic islets of diabetic NOD mice, but not of non-diabetic DBA/1 mice. Expression of CD44 on insulin-secreting β cells renders them susceptible to the autoimmune attack, and is associated with a diminution in β-cells function (e.g., less insulin production and/or insulin secretion) and possibly also with an enhanced apoptosis rate. The diabetes-supportive effect of CD44 expression on β cells was assessed by the TUNEL assay and further strengthened by functional assays exhibiting increased nitric oxide release, reduced insulin secretion after glucose stimulation and decreased insulin content in β cells. All these parameters could not be detected in CD44-deficient islets. We further suggest that HA-binding to CD44-expressing β cells is implicated in β-cell demise. Altogether, these data agree with the concept that CD44 is a receptor capable of modulating cell fate. This finding is important for other pathologies (e.g., cancer, neurodegenerative diseases) in which CD44 and HA appear to be implicated. PMID:26624007

  14. Can CD44 Be a Mediator of Cell Destruction? The Challenge of Type 1 Diabetes.

    PubMed

    Assayag-Asherie, Nathalie; Sever, Dror; Bogdani, Marika; Johnson, Pamela; Weiss, Talya; Ginzberg, Ariel; Perles, Sharon; Weiss, Lola; Sebban, Lora Eshkar; Turley, Eva A; Okon, Elimelech; Raz, Itamar; Naor, David

    2015-01-01

    CD44 is a multi-functional receptor with multiple of isoforms engaged in modulation of cell trafficking and transmission of apoptotic signals. We have previously shown that injection of anti-CD44 antibody into NOD mice induced resistance to type 1 diabetes (T1D). In this communication we describe our efforts to understand the mechanism underlying this effect. We found that CD44-deficient NOD mice develop stronger resistance to T1D than wild-type littermates. This effect is not explained by the involvement of CD44 in cell migration, because CD44-deficient inflammatory cells surprisingly had greater invasive potential than the corresponding wild type cells, probably owing to molecular redundancy. We have previously reported and we show here again that CD44 expression and hyaluronic acid (HA, the principal ligand for CD44) accumulation are detected in pancreatic islets of diabetic NOD mice, but not of non-diabetic DBA/1 mice. Expression of CD44 on insulin-secreting β cells renders them susceptible to the autoimmune attack, and is associated with a diminution in β-cells function (e.g., less insulin production and/or insulin secretion) and possibly also with an enhanced apoptosis rate. The diabetes-supportive effect of CD44 expression on β cells was assessed by the TUNEL assay and further strengthened by functional assays exhibiting increased nitric oxide release, reduced insulin secretion after glucose stimulation and decreased insulin content in β cells. All these parameters could not be detected in CD44-deficient islets. We further suggest that HA-binding to CD44-expressing β cells is implicated in β-cell demise. Altogether, these data agree with the concept that CD44 is a receptor capable of modulating cell fate. This finding is important for other pathologies (e.g., cancer, neurodegenerative diseases) in which CD44 and HA appear to be implicated. PMID:26624007

  15. Comparative evaluation of salivary soluble CD44 levels in periodontal health and disease

    PubMed Central

    Kaur, Sumeet; Narayanswamy, Savitha; Ramesh, Alampalli Viswanathamurthy

    2014-01-01

    Context: Inflammation, immunoactivation, and malignant diseases are associated with increased plasma levels of soluble CD44 (sCD44). Serum sCD44 has been recognized as a diagnostic marker in smoking-induced diseases. Aim: (1) To assess the levels of salivary sCD44 in periodontal health and disease. (2) To compare the levels of salivary sCD44 in smokers and nonsmokers. (3) To assess if salivary sCD44 levels could be used as a diagnostic marker for periodontitis. Setting and Design: A total of 60 patients were divided into three groups viz. Group A - healthy, Group B - aggressive periodontitis and Group C - chronic periodontitis (Subdivided into C1 - chronic periodontitis smokers and C2 - chronic periodontitis nonsmokers). Materials and Methods: The plaque index, gingival index (GI), probing depth and clinical attachment level; along with the radiographs were recorded. The saliva sample collected at baseline was stored at −80°C. The sCD44 levels were analyzed using ELISA. Statistical Analysis Used: ANOVA test and Mann–Whitney's test was used to compare readings between all the groups and Pearson correlation was calculated for CD44 and all the clinical parameters in each group. Results: Highest mean sCD44 was recorded in Group C2 followed by Group C1. The GI was positively correlated with CD44 levels in chronic periodontitis group. Contrary to previous reports nonsmokers subjects had higher CD44 levels as compared to smoker. Conclusion: Soluble CD44 levels were positively correlated with periodontal disease. Thus, salivary sCD44 could be considered as a one of the biomarker for periodontitis that is, aggressive and chronic periodontitis. PMID:25624630

  16. CD44 is a cytotoxic triggering molecule on human polymorphonuclear cells.

    PubMed

    Pericle, F; Sconocchia, G; Titus, J A; Segal, D M

    1996-11-15

    In this study, we present evidence that CD44 is a cytotoxic triggering molecule on freshly isolated polymorphonuclear cells (PMN). PMN constitutively express high levels of CD44 as determined by FACS analysis, and immunoprecipitation studies using PMN lysates and an anti-CD44 mAb show a band of 80 to 90 kDa that migrates slightly faster than CD44 from PBL. A bispecific Ab consisting of anti-CD44 Fab cross-linked to anti-DNP Fab (anti-CD44(Fab) x anti-DNP(Fab)) induces PMN to lyse DNP-coated tumor cells in an 18-h assay, and this lysis is specifically inhibited by a polyclonal anti-CD44 F(ab')2. A second bispecific Ab, anti-CD16(Fab) x anti-DNP(Fab), that binds to Fc(gamma)RIIIb on PMN does not induce lysis, indicating that the bridging of target cells to PMN per se is not sufficient for killing. Moreover, CD44-directed killing by PMN results in the lysis of bystander cells, suggesting that the mechanisms of tumor cytolysis by CD44-targeted PMN does not require cell-cell contact. Lastly, PMN lyse target cells coated with hyaluronic acid (HA), the principal ligand for CD44, and this cytolytic activity is specifically blocked by the polyclonal anti-CD44 F(ab')2 and by an anti-CD44 mAb. We suggest that the interaction of HA with CD44 on neutrophils might initiate cytotoxic or inflammatory responses in vivo when neutrophils encounter high amounts of HA, for example on tumor cells, or in the extracellular matrix. PMID:8906846

  17. Proteoglycan from salmon nasal cartridge promotes in vitro wound healing of fibroblast monolayers via the CD44 receptor

    SciTech Connect

    Ito, Gen; Kobayashi, Takeshi; Takeda, Yoshie; Sokabe, Masahiro

    2015-01-16

    Highlights: • Proteoglycan from salmon nasal cartridge (SNC-PG) promoted wound healing in fibroblast monolayers. • SNC-PG stimulated both cell proliferation and cell migration. • Interaction between chondroitin sulfate-units and CD44 is responsible for the effect. - Abstract: Proteoglycans (PGs) are involved in various cellular functions including cell growth, adhesion, and differentiation; however, their physiological roles are not fully understood. In this study, we examined the effect of PG purified from salmon nasal cartilage (SNC-PG) on wound closure using tissue-cultured cell monolayers, an in vitro wound-healing assay. The results indicated that SNC-PG significantly promoted wound closure in NIH/3T3 cell monolayers by stimulating both cell proliferation and cell migration. SNC-PG was effective in concentrations from 0.1 to 10 μg/ml, but showed much less effect at higher concentrations (100–1000 μg/ml). The effect of SNC-PG was abolished by chondroitinase ABC, indicating that chondroitin sulfates (CSs), a major component of glycosaminoglycans (GAGs) in SNC-PG, are crucial for the SNC-PG effect. Furthermore, chondroitin 6-sulfate (C-6-S), a major CS of SNC-PG GAGs, could partially reproduce the SNC-PG effect and partially inhibit the binding of SNC-PG to cells, suggesting that SNC-PG exerts its effect through an interaction between the GAGs in SNC-PG and the cell surface. Neutralization by anti-CD44 antibodies or CD44 knockdown abolished SNC-PG binding to the cells and the SNC-PG effect on wound closure. These results suggest that interactions between CS-rich GAG-chains of SNC-PG and CD44 on the cell surface are responsible for the SNC-PG effect on wound closure.

  18. Targeting CD44 expressing cancer cells with anti-CD44 monoclonal antibody improves cellular uptake and antitumor efficacy of liposomal doxorubicin.

    PubMed

    Arabi, Leila; Badiee, Ali; Mosaffa, Fatemeh; Jaafari, Mahmoud Reza

    2015-12-28

    Although liposomes improve the safety and pharmacokinetic properties of free drugs, they have not sufficiently enhanced the therapeutic efficacy compared to them. To address this problem, targeted therapy of tumor cells holds great promise to further enhance therapeutic index and decreases off-target effects compared with non-targeted liposomes. In the context of antibody-mediated targeted cancer therapy, we evaluated the anti-tumor activity and therapeutic efficacy of Doxil, and that of Doxil modified with a monoclonal antibody (mAb) against CD44, which is one of the most well-known surface markers associated with Cancer Stem Cells (CSCs). Flow cytometry analyses and confocal laser scanning microscopy results showed significant enhanced cellular uptake of CD44-targeted Doxil (CD44-Doxil) in CD44-positive C-26 cells compared to Doxil. However, CD44-negative NIH-3T3 cells showed a similar uptake and in vitro cytotoxicity with both CD44-Doxil and non-targeted Doxil. In BALB/c mice bearing C-26 murine carcinoma, CD44-Doxil groups exhibited significantly higher doxorubicin concentration (than Doxil) inside the tumor cells, while their circulation time and distribution profile remained comparable. CD44-Doxil at doses of either 10 or 15 mg/kg resulted in superior tumor growth inhibition and higher inclination to tumor, indicating the potential of anti-CD44 mAb targeting in therapeutic efficacy improvement. This study provides proof-of-principle for actively tumor-targeting concept and merits further investigations. PMID:26518722

  19. Phototheranostics of CD44-positive cell populations in triple negative breast cancer.

    PubMed

    Jin, Jiefu; Krishnamachary, Balaji; Mironchik, Yelena; Kobayashi, Hisataka; Bhujwalla, Zaver M

    2016-01-01

    Triple-negative breast cancer (TNBC) is one of the most lethal subtypes of breast cancer that has limited treatment options. Its high rates of recurrence and metastasis have been associated, in part, with a subpopulation of breast cancer stem-like cells that are resistant to conventional therapies. A compendium of markers such as CD44(high)/CD24(low), and increased expression of the ABCG2 transporter and increased aldehyde dehydrogenase (ALDH1), have been associated with these cells. We developed a CD44-targeted monoclonal antibody photosensitizer conjugate for combined fluorescent detection and photoimmunotherapy (PIT) of CD44 expressing cells in TNBC. The CD44-targeted conjugate demonstrated acute cell killing of breast cancer cells with high CD44 expression. This cell death process was dependent upon CD44-specific cell membrane binding combined with near-infrared irradiation. The conjugate selectively accumulated in CD44-positive tumors and caused dramatic tumor shrinkage and efficient elimination of CD44-positive cell populations following irradiation. This novel phototheranostic strategy provides a promising opportunity for the destruction of CD44-positive populations that include cancer stem-like cells, in locally advanced primary and metastatic TNBC. PMID:27302409

  20. Phototheranostics of CD44-positive cell populations in triple negative breast cancer

    PubMed Central

    Jin, Jiefu; Krishnamachary, Balaji; Mironchik, Yelena; Kobayashi, Hisataka; Bhujwalla, Zaver M.

    2016-01-01

    Triple-negative breast cancer (TNBC) is one of the most lethal subtypes of breast cancer that has limited treatment options. Its high rates of recurrence and metastasis have been associated, in part, with a subpopulation of breast cancer stem-like cells that are resistant to conventional therapies. A compendium of markers such as CD44high/CD24low, and increased expression of the ABCG2 transporter and increased aldehyde dehydrogenase (ALDH1), have been associated with these cells. We developed a CD44-targeted monoclonal antibody photosensitizer conjugate for combined fluorescent detection and photoimmunotherapy (PIT) of CD44 expressing cells in TNBC. The CD44-targeted conjugate demonstrated acute cell killing of breast cancer cells with high CD44 expression. This cell death process was dependent upon CD44-specific cell membrane binding combined with near-infrared irradiation. The conjugate selectively accumulated in CD44-positive tumors and caused dramatic tumor shrinkage and efficient elimination of CD44-positive cell populations following irradiation. This novel phototheranostic strategy provides a promising opportunity for the destruction of CD44-positive populations that include cancer stem-like cells, in locally advanced primary and metastatic TNBC. PMID:27302409

  1. Increased expression of surface CD44 in hypoxia-DCs skews helper T cells toward a Th2 polarization

    PubMed Central

    Yang, Meixiang; Liu, Yanguo; Ren, Guangwen; Shao, Qianqian; Gao, Wenjuan; Sun, Jintang; Wang, Huayang; Ji, Chunyan; Li, Xingang; Zhang, Yun; Qu, Xun

    2015-01-01

    A low partial oxygen pressure (hypoxia) occurs in many pathological environments, such as solid tumors and inflammatory lesions. Understanding the cellular response to hypoxic stress has broad implications for human diseases. As we previously reported, hypoxia significantly altered dendritic cells (DCs) to a DC2 phenotype and promoted a Th2 polarization of naïve T cells with increased IL-4 production. However, the underlying mechanisms still remain largely unknown. In this study, we found the over-expression of surface CD44 in DCs was involved in this process via ligand binding. Further investigation showed hypoxia could reduce the surface expression of membrane type 1 metalloprotease (MT1-MMP) via down-regulating the kinesin-like protein KIF2A, which subsequently alleviated the shedding of CD44 from DCs. Moreover, KIF2A expression was found negatively regulated by HIF-1α in hypoxic microenvironment. These results suggest a previously uncharacterized mechanism by which hypoxia regulates the function of DCs via KIF2A/MT1-MMP/CD44 axis, providing critical information to understand the immune response under hypoxia. PMID:26323509

  2. Localisation and endocrine control of hyaluronan synthase (HAS) 2, HAS3 and CD44 expression in sheep granulosa cells.

    PubMed

    Chavoshinejad, R; Marei, W F A; Hartshorne, G M; Fouladi-Nashta, A A

    2016-04-01

    The aim of the present study was to investigate the hormonal regulation of hyaluronan (HA) components in sheep granulosa cells. HA components are present in the reproductive tract and have a range of physical and signalling properties related to reproductive function in several species. First, abattoir-derived ovaries of sheep were used to determine the localisation of HA synthase (HAS) 1-3 and CD44 proteins in antral follicles. Staining for HAS1-3 and CD44 proteins was most intense in the granulosa layer. Accordingly, the expression of HAS2, HAS3 and CD44 mRNA was measured in cultured granulosa cells exposed to 0-50ngmL(-1) of 17β-oestradiol and different combinations of oestradiol, gonadotropins, insulin-like growth factor (IGF)-1 and insulin for 48-96h (1ngmL(-1) FSH, 10ngmL(-1) insulin, 10ngmL(-1) IGF-1, 40ngmL(-1) E2 and 25ngmL(-1) LH.). mRNA expression was quantified by real-time polymerase chain reaction using a fold induction method. The results revealed that the hormones tested generally stimulated mRNA expression of the genes of interest in cultured granulosa cells. Specifically, oestradiol, when combined with IGF-1, insulin and FSH, stimulated HAS2 mRNA expression. Oestradiol and LH had synergistic effects in increasing HAS3 mRNA expression. In conclusion, we suggest that the hormones studied differentially regulate HAS2, HAS3 and CD44 in ovine granulosa cells in vitro. Further work is needed to address the signalling pathways involved. PMID:25427133

  3. Vaginal epithelial cells regulate membrane adhesiveness to co-ordinate bacterial adhesion.

    PubMed

    Younes, Jessica A; Klappe, Karin; Kok, Jan Willem; Busscher, Henk J; Reid, Gregor; van der Mei, Henny C

    2016-04-01

    Vaginal epithelium is colonized by different bacterial strains and species. The bacterial composition of vaginal biofilms controls the balance between health and disease. Little is known about the relative contribution of the epithelial and bacterial cell surfaces to bacterial adhesion and whether and how adhesion is regulated over cell membrane regions. Here, we show that bacterial adhesion forces with cell membrane regions not located above the nucleus are stronger than with regions above the nucleus both for vaginal pathogens and different commensal and probiotic lactobacillus strains involved in health. Importantly, adhesion force ratios over membrane regions away from and above the nucleus coincided with the ratios between numbers of adhering bacteria over both regions. Bacterial adhesion forces were dramatically decreased by depleting the epithelial cell membrane of cholesterol or sub-membrane cortical actin. Thus, epithelial cells can regulate membrane regions to which bacterial adhesion is discouraged, possibly to protect the nucleus. PMID:26477544

  4. Target β-catenin/CD44/Nanog axis in colon cancer cells by certain N'-(2-oxoindolin-3-ylidene)-2-(benzyloxy)benzohydrazides.

    PubMed

    Radwan, Awwad A; Al-Mohanna, F; Alanazi, Fares K; Manogaran, P S; Al-Dhfyan, Abdullah

    2016-04-01

    Cell surface molecule CD44 plays a major role in regulation of cancer stem cells CSCs on both phenotypic and functional level, however chemical inhibition approach of CD44 to targets CSCs is poorly studied. Herein, we report the discovery of certain N'-(2-oxoindolin-3-ylidene)-2-(benzyloxy)benzohydrazides as a novel inhibitor of CD44. Molecular docking study showed interference of the scaffold of these compounds with β-catenin/TCF-4 complex, building a direct relationship between CD44 inhibition and observed well-fitted binding domain. Compound 11a, most potent member elicits inhibition effect on TCF/LEF reporter activity conformed the involvement of Wnt pathway inhibition as a mechanism of action. Furthermore, the treatment by the mentioned compound leads to inhibition of embryonic transcriptional factor Nanog but not Sox2 or Oct-4 suggested specific targeted effect. Moreover, the cytotoxicity and cell cycle effect of this series seems to be dependent on CD44 expression. PMID:26944615

  5. Expression of CD44v6 and integrin-β1 for the prognosis evaluation of pancreatic cancer patients after cryosurgery

    PubMed Central

    2013-01-01

    Background Many previous studies demonstrated that cell adhesion molecules CD44v6 and integrin-β1 had been extensively investigated as potential prognostic markers of various cancers. However, data in PC are scarce. Methods We now investigate CD44v6 and integrin-β1 mRNA expression in PBMC by a triplex real-time RT-PCR assay and protein expression in plasma by ELISA. All specimens were collected from 54 PC patients who received the treatment of cryosurgery as well as 20 healthy individuals (control). Results The mRNA and protein expression levels of CD44v6 and integrin-β1 in patients were significantly increased compared with control group (P<0.05). The high CD44v6 mRNA and protein expression were significantly correlated with clinical stage, tumor differentiation, LNM, liver metastasis and decreased median DFS (P<0.05), while the high integrin-β1 mRNA and protein expression were significantly correlated with clinical stage, LNM, liver metastasis and decreased median DFS (P<0.05). Clinical stage, LNM, liver metastasis, CD44v6 mRNA and protein expression were the independent predictors of survival in PC patients (P<0.05). Moreover, CD44v6 and integrin-β1 mRNA and protein expression levels were significantly decreased in patients in 3 months after cryosurgery (P<0.05). No significant difference was found in CD44v6 mRNA and protein expression between patients in 3 months after cryosurgery and control group (P>0.05). Conclusion CD44v6 and integrin-β1 mRNA and protein expression in blood may serve as biomarkers for the development and metastasis of PC, and as prognostic indicators for PC. They may become useful predictors in assessing outcome of PC patients after cryosurgery. Virtual slides The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/4035308681009006. PMID:24004467

  6. The CD44s splice isoform is a central mediator for invadopodia activity.

    PubMed

    Zhao, Pu; Xu, Yilin; Wei, Yong; Qiu, Qiong; Chew, Teng-Leong; Kang, Yibin; Cheng, Chonghui

    2016-04-01

    The ability for tumor cells to spread and metastasize to distant organs requires proteolytic degradation of extracellular matrix (ECM). This activity is mediated by invadopodia, actin-rich membrane protrusions that are enriched for proteases. However, the mechanisms underlying invadopodia activity are not fully understood. Here, we report that a specific CD44 splice isoform, CD44s, is an integral component in invadopodia. We show that CD44s, but not another splice isoform CD44v, is localized in invadopodia. Small hairpin (sh)RNA-mediated depletion of CD44s abolishes invadopodia activity, prevents matrix degradation and decreases tumor cell invasiveness. Our results suggest that CD44s promotes cortactin phosphorylation and recruits MT1-MMP (also known as MMP14) to sites of matrix degradation, which are important activities for invadopodia function. Importantly, we show that depletion of CD44s inhibits breast cancer cell metastasis to the lung in animals. These findings suggest a crucial mechanism underlying the role of the CD44s splice isoform in breast cancer metastasis. PMID:26869223

  7. AP-1-mediated invasion requires increased expression of the hyaluronan receptor CD44.

    PubMed Central

    Lamb, R F; Hennigan, R F; Turnbull, K; Katsanakis, K D; MacKenzie, E D; Birnie, G D; Ozanne, B W

    1997-01-01

    Fibroblasts transformed by Fos oncogenes display increased expression of a number of genes implicated in tumor cell invasion and metastasis. In contrast to normal 208F rat fibroblasts, Fos-transformed 208F fibroblasts are growth factor independent for invasion. We demonstrate that invasion of v-Fos- or epidermal growth factor (EGF)-transformed cells requires AP-1 activity. v-Fos-transformed cell invasion is inhibited by c-jun antisense oligonucleotides and by expression of a c-jun dominant negative mutant, TAM-67. EGF-induced invasion is inhibited by both c-fos and c-jun antisense oligonucleotides. CD44s, the standard form of a transmembrane receptor for hyaluronan, is implicated in tumor cell invasion and metastasis. We demonstrate that increased expression of CD44 in Fos- and EGF-transformed cells is dependent upon AP-1. CD44 antisense oligonucleotides reduce expression of CD44 in v-Fos- or EGF-transformed cells and inhibit invasion but not migration. Expression of a fusion protein between human CD44s and Aequorea victoria green fluorescent protein (GFP) in 208F cells complements the inhibition of invasion by the rat-specific CD44 antisense oligonucleotide. We further show that both v-Fos and EGF transformations result in a concentration of endogenous CD44 or exogenous CD44-GFP at the ends of pseudopodial cell extensions. These results support the hypothesis that one role of AP-1 in transformation is to activate a multigenic invasion program. PMID:9001250

  8. Conserved miR-26b enhances ovarian granulosa cell apoptosis through HAS2-HA-CD44-Caspase-3 pathway by targeting HAS2

    PubMed Central

    Liu, Jiying; Tu, Fei; Yao, Wang; Li, Xinyu; Xie, Zhuang; Liu, Honglin; Li, Qifa; Pan, Zengxiang

    2016-01-01

    The hyaluronan synthase 2 (HAS2)-hyaluronic acid (HA)-CD44-Caspase-3 pathway is involved in ovarian granulosa cell (GC) functions in mammals. HAS2 is a key enzyme required for HA synthesis and is the key factor in this pathway. However, the regulation of HAS2 and the HAS2-mediated pathway by microRNAs in GCs is poorly understood. Here, we report that miR-26b regulates porcine GC (pGC) apoptosis through the HAS2-HA-CD44-Caspase-3 pathway by binding directly to the 3′- untranslated region of HAS2 mRNA. Knockdown of miR-26b reduced pGC apoptosis. Luciferase reporter assays demonstrated that HAS2 is a direct target of miR-26b in pGCs. Knockdown and overexpression of miR-26b increased and decreased, respectively, HA content, and HAS2 and CD44 expression in pGCs. At the same time, inhibition and overexpression of miR-26b decreased and increased the expression of Caspase-3, a downstream factor in the HAS2-HA-CD44 pathway. Moreover, knockdown of HAS2 enhanced pGC apoptosis, reduced the inhibitory effects of a miR-26b inhibitor on pGC apoptosis, repressed HA content and CD44 expression, and promoted Caspase-3 expression. In addition, overexpression of HAS2 has a opposite effect. Collectively, miR-26b positively regulates pGC apoptosis via a novel HAS2-HA-CD44-Caspase-3 pathway by targeting the HAS2 gene. PMID:26887530

  9. Conserved miR-26b enhances ovarian granulosa cell apoptosis through HAS2-HA-CD44-Caspase-3 pathway by targeting HAS2.

    PubMed

    Liu, Jiying; Tu, Fei; Yao, Wang; Li, Xinyu; Xie, Zhuang; Liu, Honglin; Li, Qifa; Pan, Zengxiang

    2016-01-01

    The hyaluronan synthase 2 (HAS2)-hyaluronic acid (HA)-CD44-Caspase-3 pathway is involved in ovarian granulosa cell (GC) functions in mammals. HAS2 is a key enzyme required for HA synthesis and is the key factor in this pathway. However, the regulation of HAS2 and the HAS2-mediated pathway by microRNAs in GCs is poorly understood. Here, we report that miR-26b regulates porcine GC (pGC) apoptosis through the HAS2-HA-CD44-Caspase-3 pathway by binding directly to the 3'- untranslated region of HAS2 mRNA. Knockdown of miR-26b reduced pGC apoptosis. Luciferase reporter assays demonstrated that HAS2 is a direct target of miR-26b in pGCs. Knockdown and overexpression of miR-26b increased and decreased, respectively, HA content, and HAS2 and CD44 expression in pGCs. At the same time, inhibition and overexpression of miR-26b decreased and increased the expression of Caspase-3, a downstream factor in the HAS2-HA-CD44 pathway. Moreover, knockdown of HAS2 enhanced pGC apoptosis, reduced the inhibitory effects of a miR-26b inhibitor on pGC apoptosis, repressed HA content and CD44 expression, and promoted Caspase-3 expression. In addition, overexpression of HAS2 has a opposite effect. Collectively, miR-26b positively regulates pGC apoptosis via a novel HAS2-HA-CD44-Caspase-3 pathway by targeting the HAS2 gene. PMID:26887530

  10. Antibody against CD44s Inhibits Pancreatic Tumor Initiation and Post-Radiation Recurrence in Mice

    PubMed Central

    Li, Ling; Hao, Xinbao; Qin, Jun; Tang, Wenhua; He, Fengtian; Smith, Amber; Zhang, Min; Simeone, Diane M.; Qiao, Xiaotan T.; Chen, Zhi-Nan; Lawrence, Theodore S.; Xu, Liang

    2014-01-01

    Background & Aims CD44s is a surface marker of tumor-initiating cells (TICs); high tumor levels correlate with metastasis and recurrence, as well as poor outcomes of patients. Monoclonal antibodies against CD44s might eliminate TICs with minimal toxicity. This strategy is unclear for treatment of pancreatic cancer, and little is known about how anti-CD44s affect pancreatic cancer initiation or recurrence after radiotherapy. Methods 192 pairs of human pancreatic adenocarcinoma and adjacent non-tumor pancreatic tissues were collected from patients undergoing surgery. We measured CD44s levels in tissue samples and pancreatic cancer cell lines by immunohistochemistry, real-time PCR and immunoblot; levels were correlated with patient survival times. We studied the effects of anti-CD44s in mice with human pancreatic tumor xenografts, and used flow cytometry to determine effects on TICs. Changes in CD44s signaling were examined by real-time PCR, immunoblot, reporter assay, and in vitro tumorsphere formation assays. Results Levels of CD44s were significantly higher in pancreatic cancer than adjacent non-tumor tissues. Patients whose tumors expressed high levels of CD44s had a median survival of 10 months, compared to 43 months for those with low levels. Anti-CD44s reduced growth, metastasis, and post-radiation recurrence of pancreatic xenograft tumors in mice. The antibody reduced the number of TICs in cultured pancreatic cancer cells and in xenograft tumors, as well as their tumorigenicity. In cultured pancreatic cancer cell lines, anti-CD44s downregulated the stem cell self-renewal genes Nanog, Sox-2, and Rex-1 and inhibited STAT3-mediated cell proliferation and survival signaling. Conclusions The TIC marker CD44s is upregulated in human pancreatic tumors and associated with patient survival time. CD44s is required for initiation, growth, metastasis, and post-radiation recurrence of xenograft tumors in mice. Anti-CD44s eliminated bulk tumor cells as well as TICs from the

  11. Expression of CD44v6 gene in normal human peripheral blood

    PubMed Central

    Song, Jian; Zhang, Dong-Sheng; Zheng, Jie

    2005-01-01

    AIM: To investigate if CD44v6 could be used as a molecular marker of cancer progression and metastasis through the detection of CD44v6 gene expression in normal human peripheral blood. METHODS: RNA was extracted from the peripheral blood mononuclear cells of 50 healthy donors, the expression of CD44v6 was investigated using reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: CD44v6 mRNA was detected in 58% of healthy volunteers under the proper controls. CONCLUSION: Our results suggest that the measurement of CD44v6 expression in peripheral blood by RT-PCR is not suitable for detection of circulating tumor cells. PMID:15962382

  12. Membrane-Type 1 Matrix Metalloproteinase Cleaves Cd44 and Promotes Cell Migration

    PubMed Central

    Kajita, Masahiro; Itoh, Yoshifumi; Chiba, Tadashige; Mori, Hidetoshi; Okada, Akiko; Kinoh, Hiroaki; Seiki, Motoharu

    2001-01-01

    Migratory cells including invasive tumor cells frequently express CD44, a major receptor for hyaluronan and membrane-type 1 matrix metalloproteinase (MT1-MMP) that degrades extracellular matrix at the pericellular region. In this study, we demonstrate that MT1-MMP acts as a processing enzyme for CD44H, releasing it into the medium as a soluble 70-kD fragment. Furthermore, this processing event stimulates cell motility; however, expression of either CD44H or MT1-MMP alone did not stimulate cell motility. Coexpression of MT1-MMP and mutant CD44H lacking the MT1-MMP–processing site did not result in shedding and did not promote cell migration, suggesting that the processing of CD44H by MT1-MMP is critical in the migratory stimulation. Moreover, expression of the mutant CD44H inhibited the cell migration promoted by CD44H and MT1-MMP in a dominant-negative manner. The pancreatic tumor cell line, MIA PaCa-2, was found to shed the 70-kD CD44H fragment in a MT1-MMP–dependent manner. Expression of the mutant CD44H in the cells as well as MMP inhibitor treatment effectively inhibited the migration, suggesting that MIA PaCa-2 cells indeed use the CD44H and MT1-MMP as migratory devices. These findings revealed a novel interaction of the two molecules that have each been implicated in tumor cell migration and invasion. PMID:11381077

  13. Adhesion in the stem cell niche: biological roles and regulation

    PubMed Central

    Chen, Shuyi; Lewallen, Michelle; Xie, Ting

    2013-01-01

    Stem cell self-renewal is tightly controlled by the concerted action of stem cell-intrinsic factors and signals within the niche. Niche signals often function within a short range, allowing cells in the niche to self-renew while their daughters outside the niche differentiate. Thus, in order for stem cells to continuously self-renew, they are often anchored in the niche via adhesion molecules. In addition to niche anchoring, however, recent studies have revealed other important roles for adhesion molecules in the regulation of stem cell function, and it is clear that stem cell-niche adhesion is crucial for stem cell self-renewal and is dynamically regulated. Here, we highlight recent progress in understanding adhesion between stem cells and their niche and how this adhesion is regulated. PMID:23250203

  14. Detection of the hyaluronan receptor CD44 in the bovine oviductal epithelium.

    PubMed

    Bergqvist, Ann-Sofi; Yokoo, Masaki; Båge, Renée; Sato, Eimei; Rodríguez-Martínez, Heriberto

    2005-08-01

    Hyaluronan is involved in fundamental reproductive events such as sperm storage in the female reproductive tract, fertilization, and early embryo development, these functions are presumably mediated by its major cell surface receptor, CD44. The present study was conducted to investigate the presence and localization of CD44 in the bovine oviductal epithelium, using immunohistochemical and Western blot methods on tissue sections and epithelial cell extracts collected from the uterotubal junction (UTJ), isthmus, and ampulla of animals in the oestrus or luteal phase of the oestrous cycle. While positive immunolabelling for CD44 was found on the ad-luminal surface and supra-nuclear region of epithelial cells in all tubal segments investigated, in the UTJ, there were epithelial cells in which the entire cytoplasm positively stained. We found no differences in terms of CD44-positive staining between the different stages of the oestrous cycle. Presence of CD44 was detected by Western blotting in the tubal epithelium as a single band at 200 kDa. Although it appeared in all tubal segments, the expression of CD44 protein was more accentuated in the sperm reservoir (UTJ) than in the other segments. This is the first time CD44 has been detected in the epithelium of the tubal sperm reservoir in cattle, suggesting a pathway for the action of hyaluronan in this segment. PMID:15846044

  15. CD44 Promotes Intoxication by the Clostridial Iota-Family Toxins

    PubMed Central

    Wigelsworth, Darran J.; Ruthel, Gordon; Schnell, Leonie; Herrlich, Peter; Blonder, Josip; Veenstra, Timothy D.; Carman, Robert J.; Wilkins, Tracy D.; Van Nhieu, Guy Tran; Pauillac, Serge; Gibert, Maryse; Sauvonnet, Nathalie; Stiles, Bradley G.; Popoff, Michel R.; Barth, Holger

    2012-01-01

    Various pathogenic clostridia produce binary protein toxins associated with enteric diseases of humans and animals. Separate binding/translocation (B) components bind to a protein receptor on the cell surface, assemble with enzymatic (A) component(s), and mediate endocytosis of the toxin complex. Ultimately there is translocation of A component(s) from acidified endosomes into the cytosol, leading to destruction of the actin cytoskeleton. Our results revealed that CD44, a multifunctional surface protein of mammalian cells, facilitates intoxication by the iota family of clostridial binary toxins. Specific antibody against CD44 inhibited cytotoxicity of the prototypical Clostridium perfringens iota toxin. Versus CD44+ melanoma cells, those lacking CD44 bound less toxin and were dose-dependently resistant to C. perfringens iota, as well as Clostridium difficile and Clostridium spiroforme iota-like, toxins. Purified CD44 specifically interacted in vitro with iota and iota-like, but not related Clostridium botulinum C2, toxins. Furthermore, CD44 knockout mice were resistant to iota toxin lethality. Collective data reveal an important role for CD44 during intoxication by a family of clostridial binary toxins. PMID:23236484

  16. Ligand binding to anti-cancer target CD44 investigated by molecular simulations.

    PubMed

    Nguyen, Tin Trung; Tran, Duy Phuoc; Pham Dinh Quoc Huy; Hoang, Zung; Carloni, Paolo; Van Pham, Phuc; Nguyen, Chuong; Li, Mai Suan

    2016-07-01

    CD44 is a cell-surface glycoprotein and receptor for hyaluronan, one of the major components of the tumor extracellular matrix. There is evidence that the interaction between CD44 and hyaluronan promotes breast cancer metastasis. Recently, the molecule F-19848A was shown to inhibit hyaluronan binding to receptor CD44 in a cell-based assay. In this study, we investigated the mechanism and energetics of F-19848A binding to CD44 using molecular simulation. Using the molecular mechanics/Poisson Boltzmann surface area (MM-PBSA) method, we obtained the binding free energy and inhibition constant of the complex. The van der Waals (vdW) interaction and the extended portion of F-19848A play key roles in the binding affinity. We screened natural products from a traditional Chinese medicine database to search for CD44 inhibitors. From combining pharmaceutical requirements with docking and molecular dynamics simulations, we found ten compounds that are potentially better or equal to the F-19848A ligand at binding to CD44 receptor. Therefore, we have identified new candidates of CD44 inhibitors, based on molecular simulation, which may be effective small molecules for the therapy of breast cancer. PMID:27342250

  17. Mussel adhesion is dictated by time-regulated secretion and molecular conformation of mussel adhesive proteins

    PubMed Central

    Petrone, Luigi; Kumar, Akshita; Sutanto, Clarinda N.; Patil, Navinkumar J.; Kannan, Srinivasaraghavan; Palaniappan, Alagappan; Amini, Shahrouz; Zappone, Bruno; Verma, Chandra; Miserez, Ali

    2015-01-01

    Interfacial water constitutes a formidable barrier to strong surface bonding, hampering the development of water-resistant synthetic adhesives. Notwithstanding this obstacle, the Asian green mussel Perna viridis attaches firmly to underwater surfaces via a proteinaceous secretion (byssus). Extending beyond the currently known design principles of mussel adhesion, here we elucidate the precise time-regulated secretion of P. viridis mussel adhesive proteins. The vanguard 3,4-dihydroxy-L-phenylalanine (Dopa)-rich protein Pvfp-5 acts as an adhesive primer, overcoming repulsive hydration forces by displacing surface-bound water and generating strong surface adhesion. Using homology modelling and molecular dynamics simulations, we find that all mussel adhesive proteins are largely unordered, with Pvfp-5 adopting a disordered structure and elongated conformation whereby all Dopa residues reside on the protein surface. Time-regulated secretion and structural disorder of mussel adhesive proteins appear essential for optimizing extended nonspecific surface interactions and byssus' assembly. Our findings reveal molecular-scale principles to help the development of wet-resistant adhesives. PMID:26508080

  18. Mussel adhesion is dictated by time-regulated secretion and molecular conformation of mussel adhesive proteins.

    PubMed

    Petrone, Luigi; Kumar, Akshita; Sutanto, Clarinda N; Patil, Navinkumar J; Kannan, Srinivasaraghavan; Palaniappan, Alagappan; Amini, Shahrouz; Zappone, Bruno; Verma, Chandra; Miserez, Ali

    2015-01-01

    Interfacial water constitutes a formidable barrier to strong surface bonding, hampering the development of water-resistant synthetic adhesives. Notwithstanding this obstacle, the Asian green mussel Perna viridis attaches firmly to underwater surfaces via a proteinaceous secretion (byssus). Extending beyond the currently known design principles of mussel adhesion, here we elucidate the precise time-regulated secretion of P. viridis mussel adhesive proteins. The vanguard 3,4-dihydroxy-L-phenylalanine (Dopa)-rich protein Pvfp-5 acts as an adhesive primer, overcoming repulsive hydration forces by displacing surface-bound water and generating strong surface adhesion. Using homology modelling and molecular dynamics simulations, we find that all mussel adhesive proteins are largely unordered, with Pvfp-5 adopting a disordered structure and elongated conformation whereby all Dopa residues reside on the protein surface. Time-regulated secretion and structural disorder of mussel adhesive proteins appear essential for optimizing extended nonspecific surface interactions and byssus' assembly. Our findings reveal molecular-scale principles to help the development of wet-resistant adhesives. PMID:26508080

  19. Mussel adhesion is dictated by time-regulated secretion and molecular conformation of mussel adhesive proteins

    NASA Astrophysics Data System (ADS)

    Petrone, Luigi; Kumar, Akshita; Sutanto, Clarinda N.; Patil, Navinkumar J.; Kannan, Srinivasaraghavan; Palaniappan, Alagappan; Amini, Shahrouz; Zappone, Bruno; Verma, Chandra; Miserez, Ali

    2015-10-01

    Interfacial water constitutes a formidable barrier to strong surface bonding, hampering the development of water-resistant synthetic adhesives. Notwithstanding this obstacle, the Asian green mussel Perna viridis attaches firmly to underwater surfaces via a proteinaceous secretion (byssus). Extending beyond the currently known design principles of mussel adhesion, here we elucidate the precise time-regulated secretion of P. viridis mussel adhesive proteins. The vanguard 3,4-dihydroxy-L-phenylalanine (Dopa)-rich protein Pvfp-5 acts as an adhesive primer, overcoming repulsive hydration forces by displacing surface-bound water and generating strong surface adhesion. Using homology modelling and molecular dynamics simulations, we find that all mussel adhesive proteins are largely unordered, with Pvfp-5 adopting a disordered structure and elongated conformation whereby all Dopa residues reside on the protein surface. Time-regulated secretion and structural disorder of mussel adhesive proteins appear essential for optimizing extended nonspecific surface interactions and byssus' assembly. Our findings reveal molecular-scale principles to help the development of wet-resistant adhesives.

  20. CD44/CD24 immunophenotypes on clinicopathologic features of salivary glands malignant neoplasms

    PubMed Central

    2013-01-01

    Background Salivary Glands Malignant Neoplasms (SGMNs) account for 3-6% of head and neck cancers and 0.3% of all cancers. Tumor cells that express CD44 and CD24 exhibit a stem-cell-like behavior. CD44 is the binding site for hyaluronic acid, and CD24 is a receptor that interacts with P-selectin to induce metastasis and tumor progression. The present study aims to evaluate the expression of CD44 and CD24 on SGMNs and correlated these data with several clinicopathologic features. Methods Immunohistochemical stains for CD44 and CD24 were performed on tissue microarrays containing SGMN samples from 69 patients. The CD44, CD24 and CD44/CD24 expression phenotypes were correlated to patient clinicopathologic features and outcome. Results CD44 expression was associated with the primary site of neoplasm (p = 0.046). CD24 was associated with clinical stage III/IV (p = 0.008), T stage (p = 0,27) and lymph node (p = 0,001). The CD44/CD24 profiles were associated with the primary site of injury (p = 0.005), lymph node (p = 0.011) and T stage (p = 0.023). Univariate analysis showed a significant relationship between clinical staging and disease- free survival (p = 0.009), and the overall survival presents relation with male gender (p = 0.011) and metastasis (p = 0.027). Conclusion In summary, our investigation confirms that the clinical stage, in accordance with the literature, is the main prognostic factor for SGMN. Additionally, we have presented some evidence that the analysis of isolated CD44 and CD24 immunoexpression or the two combined markers could give prognostic information associated to clinicopathologic features in SGMN. Virtual Slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1284611098470676. PMID:23419168

  1. A switch from CD44⁺ cell to EMT cell drives the metastasis of prostate cancer.

    PubMed

    Shang, Zhiqun; Cai, Qiliang; Zhang, Minghao; Zhu, Shimiao; Ma, Yuan; Sun, Libin; Jiang, Ning; Tian, Jing; Niu, Xiaodan; Chen, Jiatong; Sun, Yinghao; Niu, Yuanjie

    2015-01-20

    Epithelial-mesenchymal transition (EMT) has been linked to cancer stem-like (CD44+) cell in the prostate cancer (PCa) metastasis. However, the molecular mechanism remains elusive. Here, we found EMT contributed to metastasis in PCa patients failed in androgen deprivation therapy (ADT). Castration TRAMP model also proved PCa treated with ADT promoted EMT with increased CD44+ stem-like cells. Switched CD44+ cell to EMT cell is a key step for luminal PCa cell metastasis. Our results also suggested ADT might go through promoting TGFβ1-CD44 signaling to enhance swift to EMT. Targeting CD44 with salinomycin and siRNA could inhibit cell transition and decrease PCa invasion. Together, cancer stem-like (CD44+) cells could be the initiator cells of EMT modulated by TGFβ1-CD44 signaling. Combined therapy of ADT with anti-CD44 may become a new potential therapeutic approach to battle later stage PCa. PMID:25483103

  2. miR-199a-3p targets CD44 and reduces proliferation of CD44 positive hepatocellular carcinoma cell lines

    SciTech Connect

    Henry, Jon C.; Park, Jong-Kook; Jiang, Jinmai; Kim, Ji Hye; Nagorney, David M.; Roberts, Lewis R.; Banerjee, Soma; Schmittgen, Thomas D.

    2010-12-03

    Research highlights: {yields} miR-199a-3p targets CD44 in HCC. {yields} Proliferation and invasion are reduced by miR-199a-3p in CD44+ HCC. {yields} miR-199a-3p is reduced and CD44 protein is increased in HCC tissues. {yields} The duplex form of miR-199a-3p mimetic is required for activity. -- Abstract: Previous work by us and others reported decreased expression of miR-199a-3p in hepatocellular carcinoma (HCC) tissues compared to adjacent benign tissue. We report here a significant reduction of miR-199a-3p expression in 7 HCC cell lines. To determine if miR-199a-3p has a tumor suppressive role, pre-miR-199a-3p oligonucleotides were transfected into the HCC cell lines. Pre-miR-199a-3p oligonucleotide reduced cell proliferation by approximately 60% compared to control oligonucleotide in only two cell lines (SNU449 and SNU423); the proliferation of the other 5 treated cell lines was similar to control oligonucleotide. A pre-miR-199a-3p oligonucleotide formulated with chemical modifications to enhance stability while preserving processing, reduced cell proliferation in SNU449 and SNU423 to the same extent as the commercially available pre-miR-199a-3p oligonucleotide. Furthermore, only the duplex miR-199a-3p oligonucleotide, and not the guide strand alone, was effective at reducing cell viability. Since a CD44 variant was essential for c-Met signaling [V. Orian-Rousseau, L. Chen, J.P. Sleeman, P. Herrlich, H. Ponta, CD44 is required for two consecutive steps in HGF/c-Met signaling, Genes Dev. 16 (2002) 3074-3086] and c-Met is a known miR-199a-3p target, we hypothesized that miR-199a-3p may also target CD44. Immunoblotting confirmed that only the two HCC lines that were sensitive to the effects of pre-miR-199a-3p were CD44+. Direct targeting of CD44 by miR-199a-3p was confirmed using luciferase reporter assays and immunoblotting. Transfection of miR-199a-3p into SNU449 cells reduced in vitro invasion and sensitized the cells to doxorubicin; both effects were enhanced

  3. The critical role of CD133+CD44+/high tumor cells in hematogenous metastasis of liver cancers

    PubMed Central

    Hou, Ying; Zou, Qifei; Ge, Ruiliang; Shen, Feng; Wang, Yizheng

    2012-01-01

    Metastatic hepatocellular carcinoma (HCC) is one of the most lethal cancers worldwide. However, the cell population responsible for its metastasis remains largely unknown. Here, we reported that CD133+CD44+/high defined a subgroup of tumor cells that was responsible for hematogenous metastasis of liver cancers. Immunohistochemical investigation of human HCC specimens revealed that the number of CD133+ and CD44+ HCC cells was increased and was associated with portal vein invasion. Purified CD133+ or CD44high HCC cells were superior in clonogenic growth and vascular invasion, respectively. Thus, the combination of CD133 and CD44 was used to define a novel HCC sub-population. CD133+CD44high, but not CD133+CD44low/−, CD133−CD44high or CD133−CD44low/− xenografts, produced intrahepatic or lung metastasis in nude mice. Further analysis of human HCC samples by flow cytometry showed that the number of CD133+CD44+ tumor cells was associated with portal vein metastasis. The cDNA microarray analysis of CD133+CD44+ and CD133+CD44− tumor cells isolated from metastatic HCC patients revealed that these cells comprised of two different populations possessing distinct gene expression profiles. Our results suggest that CD133+CD44+ tumor cells are a particular population responsible for hematogenous metastasis in liver cancers and that these cells might be targets for treatment of HCC metastasis. PMID:21862973

  4. CD44 Splice Variant v8-10 as a Marker of Serous Ovarian Cancer Prognosis.

    PubMed

    Sosulski, Amanda; Horn, Heiko; Zhang, Lihua; Coletti, Caroline; Vathipadiekal, Vinod; Castro, Cesar M; Birrer, Michael J; Nagano, Osamu; Saya, Hideyuki; Lage, Kasper; Donahoe, Patricia K; Pépin, David

    2016-01-01

    CD44 is a transmembrane hyaluronic acid receptor gene that encodes over 100 different tissue-specific protein isoforms. The most ubiquitous, CD44 standard, has been used as a cancer stem cell marker in ovarian and other cancers. Expression of the epithelial CD44 variant containing exons v8-10 (CD44v8-10) has been associated with more chemoresistant and metastatic tumors in gastrointestinal and breast cancers, but its role in ovarian cancer is unknown; we therefore investigated its use as a prognostic marker in this disease. The gene expression profiles of 254 tumor samples from The Cancer Genome Atlas RNAseqV2 were analyzed for the presence of CD44 isoforms. A trend for longer survival was observed in patients with high expression of CD44 isoforms that include exons v8-10. Immunohistochemical (IHC) analysis of tumors for presence of CD44v8-10 was performed on an independent cohort of 210 patients with high-grade serous ovarian cancer using a tumor tissue microarray. Patient stratification based on software analysis of staining revealed a statistically significant increase in survival in patients with the highest levels of transmembrane protein expression (top 10 or 20%) compared to those with the lowest expression (bottom 10 and 20%) (p = 0.0181, p = 0.0262 respectively). Expression of CD44v8-10 in primary ovarian cancer cell lines was correlated with a predominantly epithelial phenotype characterized by high expression of epithelial markers and low expression of mesenchymal markers by qPCR, Western blot, and IHC. Conversely, detection of proteolytically cleaved and soluble extracellular domain of CD44v8-10 in patient ascites samples was correlated with significantly worse prognosis (p<0.05). Therefore, presence of transmembrane CD44v8-10 on the surface of primary tumor cells may be a marker of a highly epithelial tumor with better prognosis while enzymatic cleavage of CD44v8-10, as detected by presence of the soluble extracellular domain in ascites fluid, may be

  5. CD44 Gene Polymorphisms and Environmental Factors on Oral Cancer Susceptibility in Taiwan

    PubMed Central

    Chou, Ying-Erh; Hsieh, Ming-Ju; Hsin, Chung-Han; Chiang, Whei-Ling; Lai, Yi-Cheng; Lee, Yu-Hsien; Huang, Shu-Ching; Yang, Shun-Fa; Lin, Chiao-Wen

    2014-01-01

    Background Oral squamous cell carcinoma (OSCC) is the fourth leading cause of male cancer death in Taiwan. Exposure to environmental carcinogens is the primary risk factor for developing OSCC. CD44, a well-known tumor marker, plays a crucial role in tumor cell differentiation, invasion, and metastasis. This study investigated CD44 single-nucleotide polymorphisms (SNPs) with environmental risk factors to determine OSCC susceptibility and clinicopathological characteristics. Methodology/Principal Findings Real-time polymerase chain reaction (PCR) was used to analyze 6 SNPs of CD44 in 599 patients with oral cancer and 561 cancer-free controls. We determined that the CD44 rs187115 polymorphism carriers with the genotype AG, GG, or AG+GG were associated with oral cancer susceptibility. Among 731 smokers, CD44 polymorphisms carriers with the betel-nut chewing habit had a 10.30–37.63-fold greater risk of having oral cancer compared to CD44 wild-type (WT) carriers without the betel-nut chewing habit. Among 552 betel-nut chewers, CD44 polymorphisms carriers who smoked had a 4.23–16.11-fold greater risk of having oral cancer compared to those who carried the WT but did not smoke. Finally, we also observed that the stage III and IV oral cancer patients had higher frequencies of CD44 rs187115 polymorphisms with the variant genotype (AG+GG) compared with the wild-type (WT) carriers. Conclusion Our results suggest that gene–environment interactions between the CD44 polymorphisms and betel quid chewing and tobacco smoking increase the susceptibility to oral cancer development. Patients with CD44 rs187115 variant genotypes (AG+GG) were correlated with a higher risk of oral cancer development, and these patients may possess greater chemoresistance to advanced- to late-stage oral cancer than WT carriers do. The CD44 rs187115 polymorphism has potential predictive significance in oral carcinogenesis and also may be applied as factors to predict the clinical stage in OSCC

  6. CD44 Splice Variant v8-10 as a Marker of Serous Ovarian Cancer Prognosis

    PubMed Central

    Zhang, Lihua; Coletti, Caroline; Vathipadiekal, Vinod; Castro, Cesar M.; Birrer, Michael J.; Nagano, Osamu; Saya, Hideyuki; Lage, Kasper; Donahoe, Patricia K.; Pépin, David

    2016-01-01

    CD44 is a transmembrane hyaluronic acid receptor gene that encodes over 100 different tissue-specific protein isoforms. The most ubiquitous, CD44 standard, has been used as a cancer stem cell marker in ovarian and other cancers. Expression of the epithelial CD44 variant containing exons v8-10 (CD44v8-10) has been associated with more chemoresistant and metastatic tumors in gastrointestinal and breast cancers, but its role in ovarian cancer is unknown; we therefore investigated its use as a prognostic marker in this disease. The gene expression profiles of 254 tumor samples from The Cancer Genome Atlas RNAseqV2 were analyzed for the presence of CD44 isoforms. A trend for longer survival was observed in patients with high expression of CD44 isoforms that include exons v8-10. Immunohistochemical (IHC) analysis of tumors for presence of CD44v8-10 was performed on an independent cohort of 210 patients with high-grade serous ovarian cancer using a tumor tissue microarray. Patient stratification based on software analysis of staining revealed a statistically significant increase in survival in patients with the highest levels of transmembrane protein expression (top 10 or 20%) compared to those with the lowest expression (bottom 10 and 20%) (p = 0.0181, p = 0.0262 respectively). Expression of CD44v8-10 in primary ovarian cancer cell lines was correlated with a predominantly epithelial phenotype characterized by high expression of epithelial markers and low expression of mesenchymal markers by qPCR, Western blot, and IHC. Conversely, detection of proteolytically cleaved and soluble extracellular domain of CD44v8-10 in patient ascites samples was correlated with significantly worse prognosis (p<0.05). Therefore, presence of transmembrane CD44v8-10 on the surface of primary tumor cells may be a marker of a highly epithelial tumor with better prognosis while enzymatic cleavage of CD44v8-10, as detected by presence of the soluble extracellular domain in ascites fluid, may be

  7. Fibronectin extra domain A (EDA) sustains CD133(+)/CD44(+) subpopulation of colorectal cancer cells.

    PubMed

    Ou, Juanjuan; Deng, Jia; Wei, Xing; Xie, Ganfeng; Zhou, Rongbin; Yu, Liqing; Liang, Houjie

    2013-09-01

    Fibronectin is a major extracellular matrix glycoprotein with several alternatively spliced variants, including extra domain A (EDA), which was demonstrated to promote tumorigenesis via stimulating angiogenesis and lymphangiogenesis. Given that CD133(+)/CD44(+) cancer cells are critical in tumorigenesis of colorectal cancer (CRC), we hypothesize that fibronectin EDA may promote tumorigenesis by sustaining the properties of CD133(+)/CD44(+) colon cancer cells. We found that tumor tissue and serum EDA levels are substantially higher in advanced versus early stage human CRC. Additionally we showed that tumor tissue EDA levels are positively correlated with differentiation status and chemoresistance, and correlated with a poor prognosis of CRC patients. We also showed that in colon cancer cells SW480, CD133(+)/CD44(+) versus CD133(-)/CD44(-) cells express significantly elevated EDA receptor integrin α9β1. Silencing EDA in SW480 cells reduces spheroid formation and cells positive for CD133 or CD44, which is associated with reduced expressions of embryonic stem cell markers and increased expressions of differentiation markers. Blocking integrin α9β1 function strongly reversed the effect of EDA overexpression. We also provided evidence suggesting that EDA sustains Wnt/β-catenin signaling activity via activating integrin/FAK/ERK pathway. In xenograft models, EDA-silenced SW480 cells exhibit reduced tumorigenic and metastatic capacity. In conclusion, EDA is essential for the maintenance of the properties of CD133(+)/CD44(+) colon cancer cells. PMID:23811539

  8. Oncolytic adenoviruses kill breast cancer initiating CD44+CD24-/low cells.

    PubMed

    Eriksson, Minna; Guse, Kilian; Bauerschmitz, Gerd; Virkkunen, Pekka; Tarkkanen, Maija; Tanner, Minna; Hakkarainen, Tanja; Kanerva, Anna; Desmond, Renee A; Pesonen, Sari; Hemminki, Akseli

    2007-12-01

    Cancer stem cells have been indicated in the initiation of tumors and are even found to be responsible for relapses after apparently curative therapies have been undertaken. In breast cancer, they may reside in the CD44(+)CD24(-/low) population. The use of oncolytic adenoviruses presents an attractive anti-tumor approach for eradication of these cells because their entry occurs through infection and they are, therefore, not susceptible to those mechanisms that commonly render stem cells resistant to many drugs. We isolated CD44(+)CD24(-/low) cells from patient pleural effusions and confirmed stem cell-like features including oct4 and sox2 expression and Hoechst 33342 exclusion. CD44(+)CD24(-/low) cells, including the Hoechst excluding subpopulation, could be effectively killed by oncolytic adenoviruses Ad5/3-Delta24 and Ad5.pk7-Delta24. In mice, CD44(+)CD24(-/low) cells formed orthotopic breast tumors but virus infection prevented tumor formation. Ad5/3-Delta24 and Ad5.pk7-Delta24 were effective against advanced orthotopic CD44(+)CD24(-/low)-derived tumors. In summary, Ad5/3-Delta24 and Ad5.pk7-Delta24 can kill CD44(+)CD24(-/low), and also committed breast cancer cells, making them promising agents for treatment of breast cancer. PMID:17848962

  9. Fibronectin Extra Domain A (EDA) Sustains CD133+/CD44+ Subpopulation of Colorectal Cancer Cells

    PubMed Central

    Ou, Juanjuan; Deng, Jia; Wei, Xing; Xie, Ganfeng; Zhou, Rongbin; Yu, Liqing; Liang, Houjie

    2013-01-01

    Fibronectin is a major extracellular matrix glycoprotein with several alternatively spliced variants, including extra domain A (EDA), which was demonstrated to promote tumorigenesis via stimulating angiogenesis and lymphangiogenesis. Given that CD133+/CD44+ cancer cells are critical in tumorigenesis of colorectal cancer (CRC), we hypothesize that fibronectin EDA may promote tumorigenesis by sustaining the properties of CD133+/CD44+ colon cancer cells. We found that tumor tissue and serum EDA levels are substantially higher in advanced versus early stage human CRC. Additionally we showed that tumor tissue EDA levels are positively correlated with differentiation status and chemoresistance, and correlated with a poor prognosis of CRC patients. We also showed that in colon cancer cells SW480, CD133+/CD44+ versus CD133−/CD44− cells express significantly elevated EDA receptor integrin α9β1. Silencing EDA in SW480 cells reduces spheroid formation and cells positive for CD133 or CD44, which is associated with reduced expressions of embryonic stem cell markers and increased expressions of differentiation markers. Blocking integrin α9β1 function strongly reversed the effect of EDA overexpression. We also provided evidence suggesting that EDA sustains Wnt/β-catenin signaling activity via activating integrin/FAK/ERK pathway. In xenograft models, EDA-silenced SW480 cells exhibit reduced tumorigenic and metastatic capacity. In conclusions, EDA is essential for the maintenance of the properties of CD133+/CD44+ colon cancer cells. PMID:23811539

  10. Functionalizing Liposomes with anti-CD44 Aptamer for Selective Targeting of Cancer Cells.

    PubMed

    Alshaer, Walhan; Hillaireau, Hervé; Vergnaud, Juliette; Ismail, Said; Fattal, Elias

    2015-07-15

    CD44 receptor protein is found to be overexpressed by many tumors and is identified as one of the most common cancer stem cell surface markers including tumors affecting colon, breast, pancreas, and head and neck, making this an attractive receptor for therapeutic targeting. In this study, 2'-F-pyrimidine-containing RNA aptamer (Apt1), previously selected against CD44, was successfully conjugated to the surface of PEGylated liposomes using the thiol-maleimide click reaction. The conjugation of Apt1 to the surface of liposomes was confirmed by the change in size and zeta potential and by migration on agarose gel electrophoresis. The binding affinity of Apt1 was improved after conjugation compared to free-Apt1. The cellular uptake for Apt1-Lip was tested by flow cytometry and confocal imaging using the two CD44(+) cell lines, human lung cancer cells (A549) and human breast cancer cells (MDA-MB-231), and the CD44(-) cell line, mouse embryonic fibroblast cells (NIH/3T3). The results showed higher sensitivity and selectivity for Apt1-Lip compared to the blank liposomes (Mal-Lip). In conclusion, we demonstrate a successful conjugation of anti-CD44 aptamer to the surface of liposome and binding preference of Apt1-Lip to CD44-expressing cancer cells and conclude to a promising potency of Apt1-Lip as a specific drug delivery system. PMID:25343502

  11. Synergistic effects of CD44 and TGF-β1 through AKT/GSK-3β/β-catenin signaling during epithelial-mesenchymal transition in liver cancer cells.

    PubMed

    Park, Na Ri; Cha, Jung Hoon; Jang, Jeong Won; Bae, Si Hyun; Jang, Bohyun; Kim, Jung-Hee; Hur, Wonhee; Choi, Jong Young; Yoon, Seung Kew

    2016-09-01

    Cancer metastasis is strongly correlated with epithelial-mesenchymal transition (EMT), in which transforming growth factor-β (TGF-β) signaling plays a central role. CD44 has emerged as a cancer stem cell (CSC) marker that strongly induces EMT together with TGF-β1. This study aimed to investigate the link between high CD44 and TGF-β1 levels during EMT in HCC cell lines. FACS analysis showed high expression of CD44 in TGF-β1-positive SNU-368 cells and TGF-β1-negative SNU-354 cells. SNU-368 CD44(+) cells showed EMT through up-regulation of the AKT/GSK-3β/β-catenin pathway. By comparison, SNU-354 CD44(+) cells showed only increased N-cadherin expression, which was not accompanied by a decrease in E-cadherin expression, and also down-regulated the AKT/GSK-3β/β-catenin pathway. However, TGF-β1-stimulated SNU-354 cells (CD44/TGF-β1(+)) exhibited lower E-cadherin and higher N-cadherin expression with increased AKT/GSK-3β/β-catenin pathway activity. CD44/TGF-β1(+) SNU-354 cells also showed enhanced migration and formed larger spheres, while the TGF-β1-induced stem cell properties returned to their original state with the TGF-β1 inhibitor SB431542. SB431542-treated SNU-368 (CD44/TGF-β1(-)) cells also showed diminished N-cadherin and AKT/GSK-3β/β-catenin pathway activity and further decreased cell motility in a wound healing assay. However, CD44 knockdown in SNU-354 cells did not induce EMT even after treatment with TGF-β1. Finally, double inhibition of both CD44 and TGF-β1 further decreased migration and sphere formation more strongly than a single inhibition in SNU-368 cells. In conclusion, the current study demonstrated the synergistic interactions between CD44 and TGF-β1 in EMT induction and CSC properties through the AKT/GSK-3β/β-catenin pathway in HCC cells. PMID:27320862

  12. Role of CD44high/CD133high HCT-116 cells in the tumorigenesis of colon cancer

    PubMed Central

    Wang, Xiaoxiao; Liu, Shen-Lin

    2016-01-01

    This study aimed to explore cell surface biomarkers related to cancer stem cells (CSCs) and their role in the tumorigenesis of colon cancer. Various colon cancer cell lines were screened for CD133 and CD44 expression. CD44high/CD133high and CD44low/CD133low cells were separately isolated by Fluorescence-Activated Cell Sorting (FACS). The cell proliferation, colony formation, cell cycle characteristics, and tumorigenic properties in CD44high/CD133high and CD44low/CD133low cells were investigated through in vitro experiments and in vivo tumor xenograft models. The expression profiles of stem cell-related genes were examined by RT-PCR. With HCT-116 cells, flow cytometry analysis revealed that CD44high/CD133high cells had higher proliferation potency than CD44low/CD133low cells. Compared to CD44low/CD133low cells, CD44high/CD133high cells had more stem cell-related genes, and displayed increased tumorigenic ability. In summary, CD44high/CD133high cells isolated from HCT-116 cells harbor CSC properties that may be related to the tumor growth of colon cancer. These results suggest that CD44 and CD133 could be strong markers of colorectal cancer stem cells. PMID:26840024

  13. Role of CD44high/CD133high HCT-116 cells in the tumorigenesis of colon cancer.

    PubMed

    Zhou, Jin-Yong; Chen, Min; Ma, Long; Wang, Xiaoxiao; Chen, Yu-Gen; Liu, Shen-Lin

    2016-02-16

    This study aimed to explore cell surface biomarkers related to cancer stem cells (CSCs) and their role in the tumorigenesis of colon cancer. Various colon cancer cell lines were screened for CD133 and CD44 expression. CD44high/CD133high and CD44low/CD133low cells were separately isolated by Fluorescence-Activated Cell Sorting (FACS). The cell proliferation, colony formation, cell cycle characteristics, and tumorigenic properties in CD44high/CD133high and CD44low/CD133low cells were investigated through in vitro experiments and in vivo tumor xenograft models. The expression profiles of stem cell-related genes were examined by RT-PCR. With HCT-116 cells, flow cytometry analysis revealed that CD44high/CD133high cells had higher proliferation potency than CD44low/CD133low cells. Compared to CD44low/CD133low cells, CD44high/CD133high cells had more stem cell-related genes, and displayed increased tumorigenic ability. In summary, CD44high/CD133high cells isolated from HCT-116 cells harbor CSC properties that may be related to the tumor growth of colon cancer. These results suggest that CD44 and CD133 could be strong markers of colorectal cancer stem cells. PMID:26840024

  14. Differences in CD44 Surface Expression Levels and Function Discriminates IL-17 and IFN-γ Producing Helper T Cells

    PubMed Central

    Schumann, Julia; Stanko, Katarina; Schliesser, Ulrike; Appelt, Christine; Sawitzki, Birgit

    2015-01-01

    CD44 is a prominent activation marker which distinguishes memory and effector T cells from their naïve counterparts. It also plays a role in early T cell signaling events as it is bound to the lymphocyte-specific protein kinase and thereby enhances T cell receptor signalling. Here, we investigated whether IFN-γ and IL-17 producing T helper cells differ in their CD44 expression and their dependence of CD44 for differentiation. Stimulation of CD4+ T cells with allogeneic dendritic cells resulted in the formation of three distinguishable populations: CD44+, CD44++ and CD44+++. In vitro and in vivo generated allo-reactive IL-17 producing T helper cells were mainly CD44+++ as compared to IFN-γ+ T helper cells, which were CD44++. This effect was enhanced under polarizing conditions. T helper 17 polarization led to a shift towards the CD44+++ population, whereas T helper 1 polarization diminished this population. Furthermore, blocking CD44 decreased IL-17 secretion, while IFN-γ was barely affected. Titration experiments revealed that low T cell receptor and CD28 stimulation supported T helper 17 rather than T helper 1 development. Under these conditions CD44 could act as a co-stimulatory molecule and replace CD28. Indeed, rested CD44+++CD4+ T cells contained already more total and especially phosphorylated zeta-chain-associated protein kinase 70 as compared to CD44++ cells. Our results support the notion, that CD44 enhances T cell receptor signaling strength by delivering lymphocyte-specific protein kinase, which is required for induction of IL-17 producing T helper cells. PMID:26172046

  15. Dual-stimuli responsive hyaluronic acid-conjugated mesoporous silica for targeted delivery to CD44-overexpressing cancer cells.

    PubMed

    Zhao, Qinfu; Liu, Jia; Zhu, Wenquan; Sun, Changshan; Di, Donghua; Zhang, Ying; Wang, Pu; Wang, Zhanyou; Wang, Siling

    2015-09-01

    In this paper, a redox and enzyme dual-stimuli responsive delivery system (MSN-SS-HA) based on mesoporous silica nanoparticles (MSN) for targeted drug delivery has been developed, in which hyaluronic acid (HA) was conjugated on the surface of silica by cleavable disulfide (SS) bonds. HA possesses many attractive features, including acting as a targeting ligand and simultaneously a capping agent to achieve targeted and controlled drug release, prolonging the blood circulation time, and increasing the physiological stability and biocompatibility of MSN. The anticancer drug doxorubicin (DOX) was chosen as a model drug. In vitro drug release profiles showed that the release of DOX was markedly restricted in pH 7.4 and pH 5.0 phosphate buffer solution (PBS), while it was significantly accelerated upon the addition of glutathione (GSH)/hyaluronidases (HAase). In addition, the release was further accelerated in the presence of both GSH and HAase. Confocal laser scanning microscopy (CLSM) and fluorescence-activated cell sorting (FACS) showed that MSN-SS-HA exhibited a higher cellular uptake via cluster of differentiation antigen-44 (CD44) receptor-mediated endocytosis compared with thiol (SH)-functionalized MSN (MSN-SH) in CD44 receptor over-expressed in human HCT-116 cells. The DOX-loaded MSN-SS-HA was more cytotoxic against HCT-116 cells than NIH-3T3 (CD44 receptor-negative) cells due to the enhanced cellular uptake of MSN-SS-HA. This paper describes the development of an effective method for using a single substance as multi-functional material for MSN to simultaneously regulate drug release and achieve targeted delivery. PMID:25985912

  16. ALDH/CD44 identifies uniquely tumorigenic cancer stem cells in salivary gland mucoepidermoid carcinomas.

    PubMed

    Adams, April; Warner, Kristy; Pearson, Alexander T; Zhang, Zhaocheng; Kim, Hong Sun; Mochizuki, Daiki; Basura, Gregory; Helman, Joseph; Mantesso, Andrea; Castilho, Rogério M; Wicha, Max S; Nör, Jacques E

    2015-09-29

    A small sub-population of cells characterized by increased tumorigenic potential, ability to self-renew and to differentiate into cells that make up the tumor bulk, has been characterized in some (but not all) tumor types. These unique cells, namedcancer stem cells, are considered drivers of tumor progression in these tumors. The purpose of this work is to understand if cancer stem cells play a functional role in the tumorigenesis of salivary gland mucoepidermoid carcinomas. Here, we investigated the expression of putative cancer stem cell markers (ALDH, CD10, CD24, CD44) in primary human mucoepidermoid carcinomas by immunofluorescence, in vitro salisphere assays, and in vivo tumorigenicity assays in immunodeficient mice. Human mucoepidermoid carcinoma cells (UM-HMC-1, UM-HMC-3A, UM-HMC-3B) sorted for high levels of ALDH activity and CD44 expression (ALDHhighCD44high) consistently formed primary and secondary salispheres in vitro, and showed enhanced tumorigenic potential in vivo (defined as time to tumor palpability, tumor growth after palpability), when compared to ALDHlowCD44low cells. Cells sorted for CD10/CD24, and CD10/CD44 showed varying trends of salisphere formation, but consistently low in vivo tumorigenic potential. And finally, cells sorted for CD44/CD24 showed inconsistent results in salisphere formation and tumorigenic potential assays when different cell lines were evaluated. Collectively, these data demonstrate that salivary gland mucoepidermoid carcinomas contain a small population of cancer stem cells with enhanced tumorigenic potential and that are characterized by high ALDH activity and CD44 expression. These results suggest that patients with mucoepidermoid carcinoma might benefit from therapies that ablate these highly tumorigenic cells. PMID:26449187

  17. Cell Membrane CD44v6 Levels in Squamous Cell Carcinoma of the Lung: Association with High Cellular Proliferation and High Concentrations of EGFR and CD44v5

    PubMed Central

    Ruibal, Álvaro; Aguiar, Pablo; Del Río, María Carmen; Nuñez, Matilde Isabel; Pubul, Virginia; Herranz, Michel

    2015-01-01

    Membranous CD44v6 levels in tumors and surrounding samples obtained from 94 patients with squamous cell lung carcinomas were studied and compared to clinical stage, cellular proliferation, membranous CD44v5 levels, epidermal growth factor receptor EGFR and cytoplasmatic concentrations of CYFRA 21.1. CD44v6 positive values were observed in 33/38 non-tumor samples and in 76/94 tumor samples, but there were not statistically significant differences between both subgroups. In CD44v6 positive tumor samples, CD44v6 was not associated with clinical stage, histological grade, ploidy and lymph node involvement, but significant association was found with high cellular proliferation. Likewise, CD44v6 positive tumors had significantly higher levels of EGFR and CD44v5. In patients with squamous cell lung carcinomas and clinical stage I, positive CD44v6 cases were associated with the same parameters. Furthermore, positive CD44v5 squamous tumors were associated significantly with histological grade III and lower levels of CYFRA21.1. Our findings support the value of CD44v6 as a possible indicator of poor outcome in patients with squamous lung carcinomas. PMID:25809603

  18. Cell membrane CD44v6 levels in squamous cell carcinoma of the lung: association with high cellular proliferation and high concentrations of EGFR and CD44v5.

    PubMed

    Ruibal, Álvaro; Aguiar, Pablo; Del Río, María Carmen; Nuñez, Matilde Isabel; Pubul, Virginia; Herranz, Michel

    2015-01-01

    Membranous CD44v6 levels in tumors and surrounding samples obtained from 94 patients with squamous cell lung carcinomas were studied and compared to clinical stage, cellular proliferation, membranous CD44v5 levels, epidermal growth factor receptor EGFR and cytoplasmatic concentrations of CYFRA 21.1. CD44v6 positive values were observed in 33/38 non-tumor samples and in 76/94 tumor samples, but there were not statistically significant differences between both subgroups. In CD44v6 positive tumor samples, CD44v6 was not associated with clinical stage, histological grade, ploidy and lymph node involvement, but significant association was found with high cellular proliferation. Likewise, CD44v6 positive tumors had significantly higher levels of EGFR and CD44v5. In patients with squamous cell lung carcinomas and clinical stage I, positive CD44v6 cases were associated with the same parameters. Furthermore, positive CD44v5 squamous tumors were associated significantly with histological grade III and lower levels of CYFRA21.1. Our findings support the value of CD44v6 as a possible indicator of poor outcome in patients with squamous lung carcinomas. PMID:25809603

  19. CD44-Tropic Polymeric Nanocarrier for Breast Cancer Targeted Rapamycin Chemotherapy

    PubMed Central

    Zhao, Yunqi; Zhang, Ti; Duan, Shaofeng; Davies, Neal M.; Forrest, M. Laird

    2014-01-01

    In contrast with the conventional targeting of nanoparticles to cancer cells with antibody or peptide conjugates, a hyaluronic acid (HA) matrix nanoparticle with intrinsic-CD44-tropism was developed to deliver rapamycin for localized CD44-positive breast cancer treatment. Rapamycin was chemically conjugated to the particle surface via a novel sustained-release linker, 3-amino-4-methoxy-benzoic acid. The release of the drug from the HA nanoparticle was improved by 42-fold compared to HA-temsirolimus in buffered saline. In CD44 positive MDA-MB-468 cells, using HA as drug delivery carrier, the cell-viability was significantly decreased compared to free rapamycin and CD44-blocked controls. Rat pharmacokinetics showed that the area-under-the-curve of HA nanoparticle formulation was 2.96-fold greater than that of the free drug, and the concomitant total body clearance was 8.82-fold slower. Moreover, in immunocompetent BALB/c mice bearing CD44-positive 4T1.2neu breast cancer, the rapamycin1loaded HA particles significantly improved animal survival, suppressed tumor growth and reduced the prevalence of lung metastasis. PMID:24637218

  20. Group A Streptococcus tissue invasion by CD44-mediated cell signalling

    NASA Astrophysics Data System (ADS)

    Cywes, Colette; Wessels, Michael R.

    2001-12-01

    Streptococcus pyogenes (also known as group A Streptococcus, GAS), the agent of streptococcal sore throat and invasive soft-tissue infections, attaches to human pharyngeal or skin epithelial cells through specific recognition of its hyaluronic acid capsular polysaccharide by the hyaluronic-acid-binding protein CD44 (refs 1, 2). Because ligation of CD44 by hyaluronic acid can induce epithelial cell movement on extracellular matrix, we investigated whether molecular mimicry by the GAS hyaluronic acid capsule might induce similar cellular responses. Here we show that CD44-dependent GAS binding to polarized monolayers of human keratinocytes induced marked cytoskeletal rearrangements manifested by membrane ruffling and disruption of intercellular junctions. Transduction of the signal induced by GAS binding to CD44 on the keratinocyte surface involved Rac1 and the cytoskeleton linker protein ezrin, as well as tyrosine phosphorylation of cellular proteins. Studies of bacterial translocation in two models of human skin indicated that cell signalling triggered by interaction of the GAS capsule with CD44 opened intercellular junctions and promoted tissue penetration by GAS through a paracellular route. These results support a model of host cytoskeleton manipulation and tissue invasion by an extracellular bacterial pathogen.

  1. Histological and prognostic importance of CD44(+) /CD24(+) /EpCAM(+) expression in clinical pancreatic cancer.

    PubMed

    Ohara, Yusuke; Oda, Tatsuya; Sugano, Masato; Hashimoto, Shinji; Enomoto, Tsuyoshi; Yamada, Keiichi; Akashi, Yoshimasa; Miyamoto, Ryoichi; Kobayashi, Akihiko; Fukunaga, Kiyoshi; Morishita, Yukio; Ohkohchi, Nobuhiro

    2013-08-01

    CD44(+) /CD24(+) /EpCAM(+) cells have been reported to be cancer stem cells in pancreatic cancer; however, the histological and clinical importance of these cells has not yet been investigated. Here we clarified the characteristics of CD44(+) /CD24(+) /EpCAM(+) cells in clinical specimens of pancreatic cancer using immunohistochemical assay. We used surgical specimens of pancreatic ductal adenocarcinoma from 101 patients. In view of tumor heterogeneity, we randomly selected 10 high-power fields per case, and triple-positive CD44(+) /CD24(+) /EpCAM(+) expression was identified using our scoring system. The distribution, histological characteristics, and prognostic importance of CD44(+) /CD24(+) /EpCAM(+) cells were then analyzed. As a result, the distribution of CD44(+) /CD24(+) /EpCAM(+) cells varied widely among the 101 cases examined, and CD44(+) /CD24(+) /EpCAM(+) expression was correlated with poor glandular differentiation and high proliferation. Survival analysis showed that CD44(+) /CD24(+) /EpCAM(+) expression was not correlated with patient outcome; however, CD44(+) /CD24(+) expression appeared to be correlated with poor prognosis. In conclusion, CD44(+) /CD24(+) /EpCAM(+) expression overlapped with poorly differentiated cells and possessed high proliferative potential in clinical pancreatic cancer. In particular, the presence of double-positive CD44(+) /CD24(+) expression seemed to have clinical relevance, associating with poor prognosis. PMID:23679813

  2. Significant elevation of tumour-associated isoforms of soluble CD44 in serum of normal individuals caused by cigarette smoking.

    PubMed

    Kittl, E M; Ruckser, R; Rech-Weichselbraun, I; Hinterberger, W; Bauer, K

    1997-02-01

    While performing a prospective study on sCD44 variant isoforms as tumour markers in certain malignancies, we detected relevant differences in the control group between non-smokers and smokers. For a detailed evaluation of these findings, serum levels of sCD44 variant proteins, including sequences encoded by exon v5 and exon v6, respectively, were adjusted to sex, age and smoking habit. We were able to demonstrate a significant elevation of serum levels of sCD44v5 and sCD44v6 in normal individuals due to cigarette smoking (non-smokers to smokers: sCD44v5: 33 +/- 11 microg/l to 62 +/- 30 microg/l; sCD44v6: 142 +/- 34 microg/l to 232 +/- 86 microg/l). Stepwise multiple linear regression analysis of the concentrations of sCD44v5 and sCD44v6 on the possible influence factors sex, age and smoking habit revealed cigarette smoking as the only factor influencing these isoforms (both p < 0.001). Further investigations have to elucidate a possible clinical importance of these findings in smokers. However, in patients with suspected or proven malignancy the diagnostic specifity of sCD44v5 and sCD44v6 is diminished due to this observation. PMID:9056747

  3. Hybrid inverse opals for regulating cell adhesion and orientation.

    PubMed

    Lu, Jie; Zheng, Fuyin; Cheng, Yao; Ding, Haibo; Zhao, Yuanjin; Gu, Zhongze

    2014-09-21

    Cell adhesion and alignment are two important considerations in tissue engineering applications as they can regulate the subsequent cell proliferation activity and differentiation program. Although many effects have been applied to regulate the adhesion or alignment of cells by using physical and chemical methods, it is still a challenge to regulate these cell behaviors simultaneously. Here, we present novel substrates with tunable nanoscale patterned structures for regulating the adhesion and alignment of cells. The substrates with different degrees of pattern orientation were achieved by customizing the amount of stretching applied to polymer inverse opal films. Cells cultured on these substrates showed an adjustable morphology and alignment. Moreover, soft hydrogels, which have poor plasticity and are difficult to cast into patterned structures, were applied to infiltrate the inverse opal structure. We demonstrated that the adhesion ratio of cells could be regulated by these hybrid substrates, as well as adjusting the cell morphology and alignment. These features of functional inverse opal substrates make them suitable for important applications in tissue engineering. PMID:25088946

  4. Hybrid inverse opals for regulating cell adhesion and orientation

    NASA Astrophysics Data System (ADS)

    Lu, Jie; Zheng, Fuyin; Cheng, Yao; Ding, Haibo; Zhao, Yuanjin; Gu, Zhongze

    2014-08-01

    Cell adhesion and alignment are two important considerations in tissue engineering applications as they can regulate the subsequent cell proliferation activity and differentiation program. Although many effects have been applied to regulate the adhesion or alignment of cells by using physical and chemical methods, it is still a challenge to regulate these cell behaviors simultaneously. Here, we present novel substrates with tunable nanoscale patterned structures for regulating the adhesion and alignment of cells. The substrates with different degrees of pattern orientation were achieved by customizing the amount of stretching applied to polymer inverse opal films. Cells cultured on these substrates showed an adjustable morphology and alignment. Moreover, soft hydrogels, which have poor plasticity and are difficult to cast into patterned structures, were applied to infiltrate the inverse opal structure. We demonstrated that the adhesion ratio of cells could be regulated by these hybrid substrates, as well as adjusting the cell morphology and alignment. These features of functional inverse opal substrates make them suitable for important applications in tissue engineering.

  5. Hyaluronan coated cerium oxide nanoparticles modulate CD44 and reactive oxygen species expression in human fibroblasts.

    PubMed

    Lord, Megan S; Farrugia, Brooke L; Yan, Claudia M Y; Vassie, James A; Whitelock, John M

    2016-07-01

    Cerium oxide nanoparticles are being widely explored for cell therapies. In this study, nanoceria was functionalized with hyaluronan (HA) using the organosilane linker, 3-aminopropyltriethoxysilane. HA-nanoceria was found to be cytocompatible and to reduce intracellular reactive oxygen species in human fibroblasts. The HA-nanoceria was found to colocalize with CD44 on the surface of the cells and once internalized traffic to the lysosomes, be degraded and induce markers of autophagy. These particles were also effective in reducing the cell surface expression of CD44. Together these data suggest that HA-nanoceria is a promising drug delivery material to target CD44-expressing cells through a variety of mechanisms. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1736-1746, 2016. PMID:26946213

  6. Hydrogen peroxide regulates cell adhesion through the redox sensor RPSA.

    PubMed

    Vilas-Boas, Filipe; Bagulho, Ana; Tenente, Rita; Teixeira, Vitor H; Martins, Gabriel; da Costa, Gonçalo; Jerónimo, Ana; Cordeiro, Carlos; Machuqueiro, Miguel; Real, Carla

    2016-01-01

    To become metastatic, a tumor cell must acquire new adhesion properties that allow migration into the surrounding connective tissue, transmigration across endothelial cells to reach the blood stream and, at the site of metastasis, adhesion to endothelial cells and transmigration to colonize a new tissue. Hydrogen peroxide (H2O2) is a redox signaling molecule produced in tumor cell microenvironment with high relevance for tumor development. However, the molecular mechanisms regulated by H2O2 in tumor cells are still poorly known. The identification of H2O2-target proteins in tumor cells and the understanding of their role in tumor cell adhesion are essential for the development of novel redox-based therapies for cancer. In this paper, we identified Ribosomal Protein SA (RPSA) as a target of H2O2 and showed that RPSA in the oxidized state accumulates in clusters that contain specific adhesion molecules. Furthermore, we showed that RPSA oxidation improves cell adhesion efficiency to laminin in vitro and promotes cell extravasation in vivo. Our results unravel a new mechanism for H2O2-dependent modulation of cell adhesion properties and identify RPSA as the H2O2 sensor in this process. This work indicates that high levels of RPSA expression might confer a selective advantage to tumor cells in an oxidative environment. PMID:26603095

  7. CD44 promotes the migration of bone marrow-derived mesenchymal stem cells toward glioma

    PubMed Central

    YIN, QIANG; ZHOU, YANG-YANG; WANG, PENG; MA, LI; LI, PENG; WANG, XIAO-GUANG; SHE, CHUN-HUA; LI, WEN-LIANG

    2016-01-01

    Previous in vivo and in vitro studies have shown that human mesenchymal stem cells (MSCs) exhibit tropism for gliomas. However, the mechanism underlying this directed migration remains unclear. The aim of the present study was to investigate the possible mechanism underlying platelet-derived growth factor-BB (PDGF-BB)-induced chemotactic migration of bone marrow-derived MSCs (BMSCs) toward glioma. Rat glioma C6 cell-conditioned medium was utilized to evaluate the chemotactic response of BMSCs toward glioma using an in vitro migration assay. Recombinant rat PDGF-BB was added to C6 cell-conditioned medium to assess its effect on the tropism of BMSCs. The effect of PDGF-BB on the expression levels of cluster of differentiation (CD)44 in BMSCs was evaluated by reverse transcription-polymerase chain reaction (RT-PCR) and immunofluorescence assays. The results revealed that chemotactic migration was induced in BMSCs by rat glioma C6 cell-conditioned medium, which was enhanced by PDGF-BB treatment in a dose-dependent manner. Furthermore, RT-PCR and immunofluorescence assays showed that CD44 expression was upregulated in BMSCs following treatment with 40 ng/ml PDGF-BB for 12 h. Additionally, 3-h pretreatment with the anti-CD44 neutralizing antibody OX-50 was observed to attenuate the tropism of BMSCs toward glioma in the presence or absence of PDGF-BB. The results of the present study indicate that CD44 mediates the tropism of BMSCs toward glioma, and PDGF-BB promotes the migration of BMSCs toward glioma via the upregulation of CD44 expression in BMSCs. These findings suggest CD44 inhibition may be a potential therapeutic target for the treatment of glioma. PMID:27073479

  8. Extracellular matrix hyaluronan signals via its CD44 receptor in the increased responsiveness to mechanical stimulation.

    PubMed

    Ferrari, L F; Araldi, D; Bogen, O; Levine, J D

    2016-06-01

    We propose that the extracellular matrix (ECM) signals CD44, a hyaluronan receptor, to increase the responsiveness to mechanical stimulation in the rat hind paw. We report that intradermal injection of hyaluronidase induces mechanical hyperalgesia, that is inhibited by co-administration of a CD44 receptor antagonist, A5G27. The intradermal injection of low (LMWH) but not high (HMWH) molecular weight hyaluronan also induces mechanical hyperalgesia, an effect that was attenuated by pretreatment with HMWH or A5G27. Pretreatment with HMWH also attenuated the hyperalgesia induced by hyaluronidase. Similarly, intradermal injection of A6, a CD44 receptor agonist, produced hyperalgesia that was inhibited by HMWH and A5G27. Inhibitors of protein kinase A (PKA) and Src, but not protein kinase C (PKC), significantly attenuated the hyperalgesia induced by both A6 and LMWH. Finally, to determine if CD44 receptor signaling is involved in a preclinical model of inflammatory pain, we evaluated the effect of A5G27 and HMWH on the mechanical hyperalgesia associated with the inflammation induced by carrageenan. Both A5G27 and HMWH attenuated carrageenan-induced mechanical hyperalgesia. Thus, while LMWH acts at its cognate receptor, CD44, to induce mechanical hyperalgesia, HMWH acts at the same receptor as an antagonist. That the local administration of HMWH or A5G27 inhibits carrageenan-induced hyperalgesia supports the suggestion that carrageenan produces changes in the ECM that contributes to inflammatory pain. These studies define a clinically relevant role for signaling by the hyaluronan receptor, CD44, in increased responsiveness to mechanical stimulation. PMID:26996509

  9. Tissue-specific promoters active in CD44+CD24-/low breast cancer cells.

    PubMed

    Bauerschmitz, Gerd J; Ranki, Tuuli; Kangasniemi, Lotta; Ribacka, Camilla; Eriksson, Minna; Porten, Marius; Herrmann, Isabell; Ristimäki, Ari; Virkkunen, Pekka; Tarkkanen, Maija; Hakkarainen, Tanja; Kanerva, Anna; Rein, Daniel; Pesonen, Sari; Hemminki, Akseli

    2008-07-15

    It has been proposed that human tumors contain stem cells that have a central role in tumor initiation and posttreatment relapse. Putative breast cancer stem cells may reside in the CD44(+)CD24(-/low) population. Oncolytic adenoviruses are attractive for killing of these cells because they enter through infection and are therefore not susceptible to active and passive mechanisms that render stem cells resistant to many drugs. Although adenoviruses have been quite safe in cancer trials, preclinical work suggests that toxicity may eventually be possible with more active agents. Therefore, restriction of virus replication to target tissues with tissues-specific promoters is appealing for improving safety and can be achieved without loss of efficacy. We extracted CD44(+)CD24(-/low) cells from pleural effusions of breast cancer patients and found that modification of adenovirus type 5 tropism with the serotype 3 knob increased gene delivery to CD44(+)CD24(-/low) cells. alpha-Lactalbumin, cyclo-oxygenase 2, telomerase, and multidrug resistance protein promoters were studied for activity in CD44(+)CD24(-/low) cells, and a panel of oncolytic viruses was subsequently constructed. Each virus featured 5/3 chimerism of the fiber and a promoter controlling expression of E1A, which was also deleted in the Rb binding domain for additional tumor selectivity. Cell killing assays identified Ad5/3-cox2L-d24 and Ad5/3-mdr-d24 as the most active agents, and these viruses were able to completely eradicate CD44(+)CD24(-/low) cells in vitro. In vivo, these viruses had significant antitumor activity in CD44(+)CD24(-/low)-derived tumors. These findings may have relevance for elimination of cancer stem cells in humans. PMID:18632604

  10. Association of CD44 Gene Polymorphism with Survival of NSCLC and Risk of Bone Metastasis

    PubMed Central

    Liu, Yaosheng; Qing, Haifeng; Su, Xiuyun; Wang, Cheng; Li, Zhuo; Liu, Shubin

    2015-01-01

    Background Previous studies have reported CD44 expression influenced the development and progression of tumors. The aim of this study was to investigate whether single-nucleotide polymorphisms (SNPs) of the CD44 gene are associated with survival of non-small cell lung cancer (NSCLC) and occurrence rate of bone metastasis. Material/Methods A total of 234 patients with NSCLC between 2003 and 2010 were enrolled in this study and 468 healthy persons were used as controls. Two polymorphisms, rs13347 and rs187115, in the CD44 gene were genotyped using DNA from blood lymphocytes. For statistical analysis we used the chi-square test, Fisher’s exact test, Kaplan-Meier method, and log-rank test. Results CD44 gene rs13347 polymorphism was not associated with NSCLC risk. For rs187115, the association with NSCLC risk was observed (P<0.001). Allele G carriers had significantly higher occurrence rates of bone metastasis (OR=0.4, 95%CI: 0.20–0.64, P<0.001) and more advanced tumor stage (OR=2.6, 95%CI: 1.50–4.45, P=0.001) compared to carriers of allele A. The survival rates for patients with AA genotype were significantly higher than for patients with the AG+GG genotypes (P<0.001). In multivariate analysis of survival in NSCLC patients, significant predictors were CD44 gene (AG+GG) (RR=0.48, 95%CI: 0.34–0.68, P<0.001), tumor stage (RR=0.45, 95%CI: 0. 0.31–0.65, P<0.001), and bone metastasis (RR=1.52, 95%CI: 1.05–2.21, P=0.027). Conclusions CD44 gene rs187115 polymorphism is a potential predictive marker of survival in NSCLC patients, and is significantly correlated with bone metastasis and tumor stage. PMID:26356590

  11. CD44 Plays a Functional Role in Helicobacter pylori-induced Epithelial Cell Proliferation

    PubMed Central

    Bertaux-Skeirik, Nina; Feng, Rui; Schumacher, Michael A.; Li, Jing; Mahe, Maxime M.; Engevik, Amy C.; Javier, Jose E.; Peek Jr, Richard M.; Ottemann, Karen; Orian-Rousseau, Veronique; Boivin, Gregory P.; Helmrath, Michael A.; Zavros, Yana

    2015-01-01

    The cytotoxin-associated gene (Cag) pathogenicity island is a strain-specific constituent of Helicobacter pylori (H. pylori) that augments cancer risk. CagA translocates into the cytoplasm where it stimulates cell signaling through the interaction with tyrosine kinase c-Met receptor, leading cellular proliferation. Identified as a potential gastric stem cell marker, cluster-of-differentiation (CD) CD44 also acts as a co-receptor for c-Met, but whether it plays a functional role in H. pylori-induced epithelial proliferation is unknown. We tested the hypothesis that CD44 plays a functional role in H. pylori-induced epithelial cell proliferation. To assay changes in gastric epithelial cell proliferation in relation to the direct interaction with H. pylori, human- and mouse-derived gastric organoids were infected with the G27 H. pylori strain or a mutant G27 strain bearing cagA deletion (∆CagA::cat). Epithelial proliferation was quantified by EdU immunostaining. Phosphorylation of c-Met was analyzed by immunoprecipitation followed by Western blot analysis for expression of CD44 and CagA. H. pylori infection of both mouse- and human-derived gastric organoids induced epithelial proliferation that correlated with c-Met phosphorylation. CagA and CD44 co-immunoprecipitated with phosphorylated c-Met. The formation of this complex did not occur in organoids infected with ∆CagA::cat. Epithelial proliferation in response to H. pylori infection was lost in infected organoids derived from CD44-deficient mouse stomachs. Human-derived fundic gastric organoids exhibited an induction in proliferation when infected with H. pylorithat was not seen in organoids pre-treated with a peptide inhibitor specific to CD44. In the well-established Mongolian gerbil model of gastric cancer, animals treated with CD44 peptide inhibitor Pep1, resulted in the inhibition of H. pylori-induced proliferation and associated atrophic gastritis. The current study reports a unique approach to study H

  12. MicroRNA-199a targets CD44 to suppress the tumorigenicity and multidrug resistance of ovarian cancer-initiating cells.

    PubMed

    Cheng, Weiwei; Liu, Te; Wan, Xiaoping; Gao, Yongtao; Wang, Hui

    2012-06-01

    In ovarian cancer, CD44(+) /CD117(+) stem cells, also known as cancer-initiating cells (CICs), are highly proliferative, have a low degree of differentiation, and are resistant to chemotherapeutics. Therefore, the CD44(+) /CD117(+) subpopulation is thought to be an important target for novel therapeutic strategies. In this study, we investigated the role of microRNA-199a (miR-199a) in ovarian cancer stem cells. Luciferase reporter gene assays confirmed that miR-199a targets CD44 via an miR-199a-binding site in the 3'-UTR. CD44(+) /CD117(+) ovarian CICs were enriched from human primary ovarian tumor tissues and confirmed by flow cytometric sorting. miR-199a was cloned and transfected into ovarian CICs. CD44 mRNA and protein expression was significantly decreased in miR-199a-transfected ovarian CICs as compared with miR-199a mutant-transfected and untransfected cells. Cell cycle analysis, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide proliferation assays, the colony formation assay and the transwell migration assay indicated that miR-199a significantly affected cell cycle regulation and suppressed the proliferation and invasive capacity of ovarian CICs in vitro. miR-199a significantly increased the chemosensitivity of ovarian CICs to cisplatin, pacitaxel, and adriamycin, and reduced mRNA expression of the multidrug resistance gene ABCG2 as compared with miR-199a mutant-transfected and untransfected cells. The expression of stemness markers was also significantly reduced in miR-199a-transfected CICs as compared with miR-199a mutant-transfected and untransfected ovarian cells. Furthermore, xenograft experiments confirmed that miR-199a suppressed the growth of xenograft tumors formed by ovarian CICs in vivo. Thus, expression of endogenous mature miR-199a may prevent tumorigenesis in human ovarian cancer by regulating expression of its target gene CD44. PMID:22498306

  13. Preclinical evaluation of 89Zr-labeled anti-CD44 monoclonal antibody RG7356 in mice and cynomolgus monkeys

    PubMed Central

    Vugts, Danielle J; Heuveling, Derrek A; Stigter-van Walsum, Marijke; Weigand, Stefan; Bergstrom, Mats; van Dongen, Guus AMS; Nayak, Tapan K

    2014-01-01

    RG7356 is a humanized antibody targeting the constant region of CD44. RG7356 was radiolabeled with 89Zr for preclinical evaluations in tumor xenograft-bearing mice and normal cynomolgus monkeys to enable study of its biodistribution and the role of CD44 expression on RG7356 uptake. Studies with 89Zr-RG7356 were performed in mice bearing tumor xenografts that differ in the level of CD44 expression (CD44+ or CD44-) and RG7356 responsiveness (resp or non-resp): MDA-MB-231 (CD44+, resp), PL45 (CD44+, non-resp) and HepG2 (CD44–, non-resp). Immuno-PET whole body biodistribution studies were performed in normal cynomolgus monkeys to determine normal organ uptake after administration of a single dose. At 1, 2, 3, and 6 days after injection, 89Zr-RG7356 uptake in MDA-MB-231 (CD44+, resp) xenografts was nearly constant and about 9 times higher than in HepG2 (CD44–, non-resp) xenografts (range 27.44 ± 12.93 to 33.13 ± 7.42% ID/g vs. 3.25 ± 0.38 to 3.90 ± 0.58% ID/g). Uptake of 89Zr-RG7356 was similar in MDA-MB-231 (CD44+, resp) and PL45 (CD44+, non-resp) xenografts. Studies in monkeys revealed antibody uptake in spleen, salivary glands and bone marrow, which might be related to the level of CD44 expression. 89Zr-RG7356 uptake in these normal organs decreased with increasing dose levels of unlabeled RG7356. 89Zr-RG7356 selectively targets CD44+ responsive and non-responsive tumors in mice and CD44+ tissues in monkeys. These studies indicate the importance of accurate antibody dosing in humans to obtain optimal tumor targeting. Moreover, efficient binding of RG7356 to CD44+ tumors may not be sufficient in itself to drive an anti-tumor response. PMID:24492295

  14. Infiltration of tumor-associated macrophages is involved in CD44 expression in clear cell renal cell carcinoma.

    PubMed

    Ma, Chaoya; Komohara, Yoshihiro; Ohnishi, Koji; Shimoji, Tetsu; Kuwahara, Nao; Sakumura, Yasuo; Matsuishi, Kozue; Fujiwara, Yukio; Motoshima, Takanobu; Takahashi, Wataru; Yamada, Sohsuke; Kitada, Shohei; Fujimoto, Naohiro; Nakayama, Toshiyuki; Eto, Masatoshi; Takeya, Motohiro

    2016-05-01

    Cancer stem-like cells (CSC) or cancer-initiating cells are now considered to be an important cell population related to cancer recurrence and the resistance to anti-cancer therapy. Tumor-associated macrophages (TAM) are a main component of stromal cells and are related to cancer progression in clear cell renal cell carcinoma (ccRCC). Because the detailed mechanisms allowing the maintenance of CSC in cancer tissues remain unclear, we investigated the relationship between TAM and CD44-expressing cancer cells in ccRCC. CD44 was used as a marker for CSC, and CD163 and CD204 were used as markers for TAM. CD44-positive cancer cells were detected in 37 of the 103 cases. Although statistical analysis showed no relationship between CD44-positive cancer cells and the clinical course, the distribution of CD44-positive cancer cells was significantly associated with a high density of TAM. Our in vitro study using RCC cell lines and human macrophages demonstrated that CD44 expression was upregulated by direct co-culture with macrophages. Silencing of TNF-alpha on macrophages abrogated the upregulation of CD44 expression in cancer cells. Macrophage-induced CD44 overexpression was also suppressed by NF-κB inhibitors. These results suggest that TNF-alpha derived from TAM is linked to CD44 overexpression via NF-κB signaling in ccRCC. PMID:26918621

  15. HDAC inhibitor AR-42 decreases CD44 expression and sensitizes myeloma cells to lenalidomide

    PubMed Central

    Sborov, Douglas W.; Cascione, Luciano; Radomska, Hanna S.; Smith, Emily; Stiff, Andrew; Consiglio, Jessica; Caserta, Enrico; Rizzotto, Lara; Zanesi, Nicola; Stefano, Volinia; Kaur, Balveen; Mo, Xiaokui; Byrd, John C.; Efebera, Yvonne A.

    2015-01-01

    Multiple myeloma (MM) is a hematological malignancy of plasma cells in the bone marrow. Despite multiple treatment options, MM is inevitably associated with drug resistance and poor outcomes. Histone deacetylase inhibitors (HDACi's) are promising novel chemotherapeutics undergoing evaluation in clinical trials for the potential treatment of patients with MM. Although in preclinical studies HDACi's have proven anti-myeloma activity, but in the clinic single-agent HDACi treatments have been limited due to low tolerability. Improved clinical outcomes were reported only when HDACi's were combined with other drugs. Here, we show that a novel pan-HDACi AR-42 downregulates CD44, a glycoprotein that has been associated with lenalidomide and dexamethasone resistance in myeloma both in vitro and in vivo. We also show that this CD44 downregulation is in part mediated by miR-9–5p, targeting insulin-like growth factor 2 mRNA binding protein 3 (IGF2BP3), which directly binds to CD44 mRNA and increases its stability. Importantly, we also demonstrate that AR-42 enhances anti-myeloma activity of lenalidomide in primary MM cells isolated from lenalidomide resistant patients and in in vivo MM mouse model. Thus, our findings shed light on potential novel combinatorial therapeutic approaches modulating CD44 expression, which may help overcome lenalidomide resistance in myeloma patients. PMID:26429859

  16. Platelet adhesion signalling and the regulation of thrombus formation.

    PubMed

    Gibbins, Jonathan M

    2004-07-15

    Platelets perform a central role in haemostasis and thrombosis. They adhere to subendothelial collagens exposed at sites of blood vessel injury via the glycoprotein (GP) Ib-V-IX receptor complex, GPVI and integrin alpha(2)beta(1). These receptors perform distinct functions in the regulation of cell signalling involving non-receptor tyrosine kinases (e.g. Src, Fyn, Lyn, Syk and Btk), adaptor proteins, phospholipase C and lipid kinases such as phosphoinositide 3-kinase. They are also coupled to an increase in cytosolic calcium levels and protein kinase C activation, leading to the secretion of paracrine/autocrine platelet factors and an increase in integrin receptor affinities. Through the binding of plasma fibrinogen and von Willebrand Factor to integrin alpha(IIb)beta(3), a platelet thrombus is formed. Although increasing evidence indicates that each of the adhesion receptors GPIb-V-IX and GPVI and integrins alpha(2)beta(1) and alpha(IIb)beta(3) contribute to the signalling that regulates this process, the individual roles of each are only beginning to be dissected. By contrast, adhesion receptor signalling through platelet endothelial cell adhesion molecule 1 (PECAM-1) is implicated in the inhibition of platelet function and thrombus formation in the healthy circulation. Recent studies indicate that understanding of platelet adhesion signalling mechanisms might enable the development of new strategies to treat and prevent thrombosis. PMID:15252124

  17. Epac Activation Regulates Human Mesenchymal Stem Cells Migration and Adhesion.

    PubMed

    Yu, Jiao-Le; Deng, Ruixia; Chung, Sookja K; Chan, Godfrey Chi-Fung

    2016-04-01

    How to enhance the homing of human mesenchymal stem cells (hMSCs) to the target tissues remains a clinical challenge nowadays. To overcome this barrier, the mechanism responsible for the hMSCs migration and engraftment has to be defined. Currently, the exact mechanism involved in migration and adhesion of hMSCs remains unknown. Exchange protein directly activated by cAMP (Epac), a novel protein discovered in cAMP signaling pathway, may have a potential role in regulating cells adhesion and migration by triggering the downstream Rap family signaling cascades. However, the exact role of Epac in cells homing is elusive. Our study evaluated the role of Epac in the homing of hMSCs. We confirmed that hMSCs expressed functional Epac and its activation enhanced the migration and adhesion of hMSCs significantly. The Epac activation was further found to be contributed directly to the chemotactic responses induced by stromal cell derived factor-1 (SDF-1) which is a known chemokine in regulating hMSCs homing. These findings suggested Epac is connected to the SDF-1 signaling cascades. In conclusion, our study revealed that Epac plays a role in hMSCs homing by promoting adhesion and migration. Appropriate manipulation of Epac may enhance the homing of hMSCs and facilitate their future clinical applications. Stem Cells 2016;34:948-959. PMID:26727165

  18. Transcriptionally Regulated Cell Adhesion Network Dictates Distal Tip Cell Directionality

    PubMed Central

    Wong, Ming-Ching; Kennedy, William P.; Schwarzbauer, Jean E.

    2015-01-01

    Background The mechanisms that govern directional changes in cell migration are poorly understood. The migratory paths of two distal tip cells (DTC) determine the U-shape of the C. elegans hermaphroditic gonad. The morphogenesis of this organ provides a model system to identify genes necessary for the DTCs to execute two stereotyped turns. Results Using candidate genes for RNAi knockdown in a DTC-specific strain, we identified two transcriptional regulators required for DTC turning: cbp-1, the CBP/p300 transcriptional coactivator homologue, and let-607, a CREBH transcription factor homologue. Further screening of potential target genes uncovered a network of integrin adhesion-related genes that have roles in turning and are dependent on cbp-1 and let-607 for expression. These genes include src-1/Src kinase, tln-1/talin, pat-2/α integrin and nmy-2, a nonmuscle myosin heavy chain. Conclusions Transcriptional regulation by means of cbp-1 and let-607 is crucial for determining directional changes during DTC migration. These regulators coordinate a gene network that is necessary for integrin-mediated adhesion. Overall, these results suggest that directional changes in cell migration rely on the precise gene regulation of adhesion. PMID:24811939

  19. Potential of sulfasalazine as a therapeutic sensitizer for CD44 splice variant 9-positive urogenital cancer.

    PubMed

    Takayama, Tatsuya; Kubo, Taro; Morikawa, Ai; Morita, Tatsuo; Nagano, Osamu; Saya, Hideyuki

    2016-05-01

    Cancer stem-like cells (CSCs) with high expression of CD44 splice variant (CD44v) have an enhanced capacity for intracellular reduced glutathione synthesis and defense against reactive oxygen species, resulting in resistance to various therapeutic stresses. Sulfasalazine (SSZ), a drug used in the treatment of rheumatoid arthritis (RA), inhibits glutamate-cystine transport, and suppressed CD44v-dependent tumor growth and increased sensitivity to cytotoxic drugs in an in vivo study. Here, we present two cases of CD44v9-positive urogenital cancer with concomitant treatment with SSZ for RA. Patient 1 was a 62-year-old man who had received SSZ for RA beginning 2 months before the diagnosis of urinary bladder cancer. Although he had multiple metastases to the bladder, abdominal, left cervical and left axillary lymph nodes, and brain, complete response with multidisciplinary therapy was maintained for more than 2 years. Patient 2 was a 74-year-old man with castration-resistant prostate cancer who was diagnosed with RA during chemotherapy and a gradual increase in prostate-specific antigen (PSA) level. When SSZ was added, his PSA value (ng/mL) decreased from 12.93 to 5.58 in only 2 weeks and then quickly rebounded, whereas levels of neuron-specific enolase, a neuroendocrine differentiator and CSC marker, remained almost unchanged. We therefore speculate that SSZ treatment may represent a new adjuvant treatment option for patients with CD44v9-positive urogenital cancer. PMID:27044355

  20. Characterization of CD44-Mediated Cancer Cell Uptake and Intracellular Distribution of Hyaluronan-Grafted Liposomes

    PubMed Central

    Qhattal, Hussaini Syed Sha; Liu, Xinli

    2011-01-01

    Hyaluronan (HA) is a biocompatible and biodegradable linear polysaccharide which is of interest for tumor targeting through cell surface CD44 receptors. HA binds with high affinity to CD44 receptors, which are overexpressed in many tumors and involved in cancer metastasis. In the present study, we investigated the impact of HA molecular weight (MW), grafting density, and CD44 receptor density on endocytosis of HA-grafted liposomes (HA-liposomes) by cancer cells. Additionally, the intracellular localization of the HA-liposomes was determined. HAs of different MWs (5-8, 10-12, 175-350, and 1600 kDa) were conjugated to liposomes with varying degrees of grafting density. HA surface density was quantified using the hexadecyltrimethylammonium bromide turbidimetric method. Cellular uptake and subcellular localization of HA-liposomes were evaluated by flow cytometry and fluorescence microscopy. Mean particle sizes of HA-liposomes ranged from 120 to 180 nm and increased with the bigger size of HA. HA-liposome uptake correlated with HA MW (5-8 < 10-12 < 175-350 kDa), grafting density, and CD44 receptor density and exceeded that obtained with unconjugated plain liposomes. HA-liposomes were taken up into cells via lipid raft-mediated endocytosis, which is both energy- and cholesterol-dependent. Once within cells, HA-liposomes localized primarily to endosomes and lysosomes. The results demonstrate that cellular targeting efficiency of HA-liposomes depends strongly upon HA MW, grafting density, and cell surface receptor CD44 density. The results support a role of HA-liposomes for targeted drug delivery. PMID:21696190

  1. Allosteric regulation of focal adhesion kinase by PIP₂ and ATP.

    PubMed

    Zhou, Jing; Bronowska, Agnieszka; Le Coq, Johanne; Lietha, Daniel; Gräter, Frauke

    2015-02-01

    Focal adhesion kinase (FAK) is a nonreceptor tyrosine kinase that regulates cell signaling, proliferation, migration, and development. A major mechanism of regulation of FAK activity is an intramolecular autoinhibitory interaction between two of its domains--the catalytic and FERM domains. Upon cell adhesion to the extracellular matrix, FAK is being translocated toward focal adhesion sites and activated. Interactions of FAK with phosphoinositide phosphatidylinsositol-4,5-bis-phosphate (PIP₂) are required to activate FAK. However, the molecular mechanism of the activation remains poorly understood. Recent fluorescence resonance energy transfer experiments revealed a closure of the FERM-kinase interface upon ATP binding, which is reversed upon additional binding of PIP₂. Here, we addressed the allosteric regulation of FAK by performing all-atom molecular-dynamics simulations of a FAK fragment containing the catalytic and FERM domains, and comparing the dynamics in the absence or presence of ATP and PIP₂. As a major conformational change, we observe a closing and opening motion upon ATP and additional PIP₂ binding, respectively, in good agreement with the fluorescence resonance energy transfer experiments. To reveal how the binding of the regulatory PIP₂ to the FERM F2 lobe is transduced to the very distant F1/N-lobe interface, we employed force distribution analysis. We identified a network of mainly charged residue-residue interactions spanning from the PIP₂ binding site to the distant interface between the kinase and FERM domains, comprising candidate residues for mutagenesis to validate the predicted mechanism of FAK activation. PMID:25650936

  2. Adamts5 Deletion Blocks Murine Dermal Repair through CD44-mediated Aggrecan Accumulation and Modulation of Transforming Growth Factor β1 (TGFβ1) Signaling*

    PubMed Central

    Velasco, Jennifer; Li, Jun; DiPietro, Luisa; Stepp, Mary Ann; Sandy, John D.; Plaas, Anna

    2011-01-01

    ADAMTS5 has been implicated in the degradation of cartilage aggrecan in human osteoarthritis. Here, we describe a novel role for the enzyme in the regulation of TGFβ1 signaling in dermal fibroblasts both in vivo and in vitro. Adamts5−/− mice, generated by deletion of exon 2, exhibit impaired contraction and dermal collagen deposition in an excisional wound healing model. This was accompanied by accumulation in the dermal layer of cell aggregates and fibroblastic cells surrounded by a pericellular matrix enriched in full-length aggrecan. Adamts5−/− wounds exhibit low expression (relative to wild type) of collagen type I and type III but show a persistently elevated expression of tgfbRII and alk1. Aggrecan deposition and impaired dermal repair in Adamts5−/− mice are both dependent on CD44, and Cd44−/−/Adamts5−/− mice display robust activation of TGFβ receptor II and collagen type III expression and the dermal regeneration seen in WT mice. TGFβ1 treatment of newborn fibroblasts from wild type mice results in Smad2/3 phosphorylation, whereas cells from Adamts5−/− mice phosphorylate Smad1/5/8. The altered TGFβ1 response in the Adamts5−/− cells is dependent on the presence of aggrecan and expression of CD44, because Cd44−/−/Adamts5−/− cells respond like WT cells. We propose that ADAMTS5 deficiency in fibrous tissues results in a poor repair response due to the accumulation of aggrecan in the pericellular matrix of fibroblast progenitor cells, which prevents their transition to mature fibroblasts. Thus, the capacity of ADAMTS5 to modulate critical tissue repair signaling events suggests a unique role for this enzyme, which sets it apart from other members of the ADAMTS family of proteases. PMID:21566131

  3. Aberrant Splicing of Estrogen Receptor, HER2, and CD44 Genes in Breast Cancer

    PubMed Central

    Inoue, Kazushi; Fry, Elizabeth A.

    2015-01-01

    Breast cancer (BC) is the most common cause of cancer-related death among women under the age of 50 years. Established biomarkers, such as hormone receptors (estrogen receptor [ER]/progesterone receptor) and human epidermal growth factor receptor 2 (HER2), play significant roles in the selection of patients for endocrine and trastuzumab therapies. However, the initial treatment response is often followed by tumor relapse with intrinsic resistance to the first-line therapy, so it has been expected to identify novel molecular markers to improve the survival and quality of life of patients. Alternative splicing of pre-messenger RNAs is a ubiquitous and flexible mechanism for the control of gene expression in mammalian cells. It provides cells with the opportunity to create protein isoforms with different, even opposing, functions from a single genomic locus. Aberrant alternative splicing is very common in cancer where emerging tumor cells take advantage of this flexibility to produce proteins that promote cell growth and survival. While a number of splicing alterations have been reported in human cancers, we focus on aberrant splicing of ER, HER2, and CD44 genes from the viewpoint of BC development. ERα36, a splice variant from the ER1 locus, governs nongenomic membrane signaling pathways triggered by estrogen and confers 4-hydroxytamoxifen resistance in BC therapy. The alternative spliced isoform of HER2 lacking exon 20 (Δ16HER2) has been reported in human BC; this isoform is associated with transforming ability than the wild-type HER2 and recapitulates the phenotypes of endocrine therapy-resistant BC. Although both CD44 splice isoforms (CD44s, CD44v) play essential roles in BC development, CD44v is more associated with those with favorable prognosis, such as luminal A subtype, while CD44s is linked to those with poor prognosis, such as HER2 or basal cell subtypes that are often metastatic. Hence, the detection of splice variants from these loci will provide keys

  4. In vivo monitoring of CD44+ cancer stem-like cells by γ-irradiation in breast cancer.

    PubMed

    Kim, Mi Hyun; Kim, Min Hwan; Kim, Kwang Seok; Park, Myung-Jin; Jeong, Jae-Hoon; Park, Seung Woo; Ji, Young Hoon; Kim, Kwang Il; Lee, Tae Sup; Ryu, Phil Youl; Kang, Joo Hyun; Lee, Yong Jin

    2016-06-01

    There is increasing evidence that cancer contains cancer stem cells (CSCs) that are capable of regenerating a tumor following chemotherapy or radiotherapy. CD44 and CD133 are used to identify CSCs. This study investigated non-invasive in vivo monitoring of CD44-positive cancer stem-like cells in breast cancer by γ-irradiation using molecular image by fusing the firefly luciferase (fLuc) gene with the CD44 promoter. We generated a breast cancer cell line stably expressing fLuc gene by use of recombinant lentiviral vector controlled by CD44 promoter (MCF7-CL). Irradiated MCF7-CL spheres showed upregulated expression of CD44 and CD133, by immunofluorescence and flow cytometry. Also, gene expression levels of CSCs markers in irradiated spheres were clearly increased. CD44+ CSCs increased fLuc expression and tumor growth in vivo and in vitro. When MCF7-CL was treated with siCD44 and irradiated, CD44 expression was inhibited and cell survival ratio was decreased. MCF7-CL subsets were injected into the mice and irradiated by using a cobalt-60 source. Then, in vivo monitoring was performed to observe the bioluminescence imaging (BLI). When breast cancer was irradiated, relative BLI signal was increased, but tumor volume was decreased compared to non-irradiated tumor. These results indicate that increased CD44 expression, caused by general feature of CSCs by irradiation and sphere formation, can be monitored by using bioluminescence imaging. This system could be useful to evaluate CD44- expressed CSCs in breast cancer by BLI in vivo as well as in vitro for radiotherapy. PMID:27098303

  5. Cationic conjugated polymer/fluoresceinamine-hyaluronan complex for sensitive fluorescence detection of CD44 and tumor-targeted cell imaging.

    PubMed

    Huang, Yanqin; Yao, Xin; Zhang, Rui; Ouyang, Lang; Jiang, Rongcui; Liu, Xingfen; Song, Caixia; Zhang, Guangwei; Fan, Quli; Wang, Lianhui; Huang, Wei

    2014-01-01

    Simple, rapid, and sensitive detection of CD44 is of paramount importance since it plays pivotal roles in tumor initiation, growth and metastasis. Herein, we describe a novel method for sensitive, visual and facile fluorescence detection of CD44 and CD44-mediated cancer cell imaging, using a probe based on cationic conjugated polymer (CCP)-PFEP and fluoresceinamine-hyaluronan (FA-HA). HA is an anionic natural glycosaminoglycan that can specifically bind to the overexpressed CD44 on various kinds of cancer cells. PFEP and FA-HA formed a complex through electronic interactions, resulting in a highly efficient fluorescence resonance energy transfer (FRET) from PFEP to FA-HA; moreover, the efficiencies of FRET correlated with the concentrations of CD44 because the specific binding of HA-CD44 would separate FA-HA away from PFEP. This method did not require laborious and expensive dual-labeling or protein-labeling needed in previously reported detection methods of CD44. Just mix the sample and test solution containing the PFEP/FA-HA complex, and the results allowed naked-eye detection by observing fluorescent color of solutions with the assistance of a UV lamp. Most importantly, the use of a conjugated polymer with excellent amplification property as well as the specific binding of HA-CD44 endowed this method with high sensitivity and specificity, making it applicable for reliable quantitative detection of CD44. Furthermore, the PFEP/FA-HA complex formed nanoparticles in aqueous solution, and the nanoparticles can be selectively taken up by MCF-7 cells (cancer cell) through the HA-CD44 interaction, thereby giving rise to a dual-color tumor-targeted imaging probe with good photostability. The development of this fluorescent probe showed promising potential to make a reliable and routine method available for early diagnosis of cancer. PMID:25278260

  6. In vivo monitoring of CD44+ cancer stem-like cells by γ-irradiation in breast cancer

    PubMed Central

    KIM, MI HYUN; KIM, MIN HWAN; KIM, KWANG SEOK; PARK, MYUNG-JIN; JEONG, JAE-HOON; PARK, SEUNG WOO; JI, YOUNG HOON; KIM, KWANG IL; LEE, TAE SUP; RYU, PHIL YOUL; KANG, JOO HYUN; LEE, YONG JIN

    2016-01-01

    There is increasing evidence that cancer contains cancer stem cells (CSCs) that are capable of regenerating a tumor following chemotherapy or radiotherapy. CD44 and CD133 are used to identify CSCs. This study investigated non-invasive in vivo monitoring of CD44-positive cancer stem-like cells in breast cancer by γ-irradiation using molecular image by fusing the firefly luciferase (fLuc) gene with the CD44 promoter. We generated a breast cancer cell line stably expressing fLuc gene by use of recombinant lentiviral vector controlled by CD44 promoter (MCF7-CL). Irradiated MCF7-CL spheres showed upregulated expression of CD44 and CD133, by immunofluorescence and flow cytometry. Also, gene expression levels of CSCs markers in irradiated spheres were clearly increased. CD44+ CSCs increased fLuc expression and tumor growth in vivo and in vitro. When MCF7-CL was treated with siCD44 and irradiated, CD44 expression was inhibited and cell survival ratio was decreased. MCF7-CL subsets were injected into the mice and irradiated by using a cobalt-60 source. Then, in vivo monitoring was performed to observe the bioluminescence imaging (BLI). When breast cancer was irradiated, relative BLI signal was increased, but tumor volume was decreased compared to non-irradiated tumor. These results indicate that increased CD44 expression, caused by general feature of CSCs by irradiation and sphere formation, can be monitored by using bioluminescence imaging. This system could be useful to evaluate CD44-expressed CSCs in breast cancer by BLI in vivo as well as in vitro for radiotherapy. PMID:27098303

  7. Expression of CD44 and CD35 during normal and myelodysplastic erythropoiesis.

    PubMed

    Laranjeira, Paula; Rodrigues, Raquel; Carvalheiro, Tiago; Constanço, Conceição; Vitória, Helena; Matarraz, Sergio; Trindade, Hélder; Órfão, Alberto; Paiva, Artur

    2015-03-01

    Erythroid dysplasia is a common feature of myelodysplastic syndromes (MDS). Currently available information about the immunophenotypic features of normal and dysplastic erythropoiesis is scarce and restricted to relatively few markers. Here we studied the expression of CD117, CD35 and CD44 throughout the normal (n=16) and dysplastic (n=48) bone marrow erythroid maturation. CD35 emerged as an early marker of CD34(+) erythroid-committed precursors, which is expressed before CD105 and remains positive thereafter. MDS patients (with and without morphologic dyserythropoiesis) displayed overall increased expression of CD44, associated with slight alterations on CD35 expression, suggesting that phenotypic alterations in MDS may precede morphologic dysplasia. In turn, MDS patients with anemia showed increased expression of CD117. PMID:25582385

  8. Hyperspectral darkfield microscopy of PEGylated gold nanoparticles targeting CD44-expressing cancer cells.

    PubMed

    Patskovsky, Sergiy; Bergeron, Eric; Meunier, Michel

    2015-01-01

    We present a new hyperspectral darkfield imaging system with a scanned broadband supercontinuum light source. We observed the specific attachment of the functionalized gold plasmonic nanoparticles (AuNPs) targeting CD44(+) human breast cancer cells by conventional and by proposed hyperspectral darkfield microscopy. This wide-field and low phototoxic hyperspectral imaging system has been successful for performing spectral three-dimensional (3D) localization and spectroscopic identification of CD44-targeted PEGylated AuNPs in fixed cell preparations. Such spatial and spectral information is essential for the improvement of nanoplasmonic-based imaging, disease detection and treatment in complex biological environment. Presented system capability for 3D NP tracking will also enable investigation of specific sub-cellular activity with the use of NPs as spectral sensors. PMID:24343875

  9. Hyaluronic acid modified mesoporous carbon nanoparticles for targeted drug delivery to CD44-overexpressing cancer cells

    NASA Astrophysics Data System (ADS)

    Wan, Long; Jiao, Jian; Cui, Yu; Guo, Jingwen; Han, Ning; Di, Donghua; Chang, Di; Wang, Pu; Jiang, Tongying; Wang, Siling

    2016-04-01

    In this paper, hyaluronic acid (HA) functionalized uniform mesoporous carbon spheres (UMCS) were synthesized for targeted enzyme responsive drug delivery using a facile electrostatic attraction strategy. This HA modification ensured stable drug encapsulation in mesoporous carbon nanoparticles in an extracellular environment while increasing colloidal stability, biocompatibility, cell-targeting ability, and controlled cargo release. The cellular uptake experiments of fluorescently labeled mesoporous carbon nanoparticles, with or without HA functionalization, demonstrated that HA-UMCS are able to specifically target cancer cells overexpressing CD44 receptors. Moreover, the cargo loaded doxorubicin (DOX) and verapamil (VER) exhibited a dual pH and hyaluronidase-1 responsive release in the tumor microenvironment. In addition, VER/DOX/HA-UMCS exhibited a superior therapeutic effect on an in vivo HCT-116 tumor in BALB/c nude mice. In summary, it is expected that HA-UMCS will offer a new method for targeted co-delivery of drugs to tumors overexpressing CD44 receptors.

  10. Concurrent CD44s and STAT3 expression in human clear cell renal cellular carcinoma and its impact on survival

    PubMed Central

    Qin, Jun; Yang, Bo; Xu, Bao-Qin; Smithc, Amber; Xu, Liang; Yuan, Jian-Lin; Li, Ling

    2014-01-01

    Although CD44 was overexpressed and considered as a useful prognostic marker in renal cell carcinoma, the prognostic role of CD44s in clear cell renal cell carcinoma (ccRCC) remains controversial. Moreover, the correlation and prognostic significance of CD44s and its downstream signaling target pSTAT3 are unclear in ccRCC. In this study, 75 pairs of carcinoma and paired adjacent non-tumor renal tissue samples were collected from patients with localized ccRCC who underwent a nephrectomy. The expression levels of CD44s and pSTAT3 were analyzed using immunohistochemistry. Correlations between CD44s/pSTAT3 expression and clinical and pathological characteristics were determined using x2 test, Kaplan-Meier analysis and Cox’s proportional hazards model. We found that CD44s is highly expressed in 46.67% of tumor tissues, and its high expression was significantly associated with high tumor grade (P < 0.001), large tumor size (P = 0.009) and advanced T stage (P = 0.004). A strong correlation exists between high expression of CD44s and pSTAT3 (r = 0.4013, P = 0.0004). The joint over expression of CD44s and pSTAT3 was present in 42.66% of tumor specimens and had an additive negative impact on overall survival. Patients with CD44shighpSTAT3high expression had significantly poor survival as compared to patients with CD44slowpSTAT3low tumor expression (P = 0.024), though the concurrent overexpression of CD44s and pSTAT3 was not an independent prognostic factor for overall survival. Our data indicate that expression of both CD44s and pSTAT3 in ccRCC is associated with advanced tumor stage and patient survival. The conclusions from this study may improve the prediction of ccRCC prognosis information when CD44s and pSTAT3 expression are evaluated together with classical clinicopathological parameters. PMID:25031744

  11. FKBPL and Peptide Derivatives: Novel Biological Agents That Inhibit Angiogenesis by a CD44-Dependent Mechanism

    PubMed Central

    Valentine, Andrea; O’Rourke, Martin; Yakkundi, Anita; Worthington, Jenny; Hookham, Michelle; Bicknell, Roy; McCarthy, Helen O.; McClelland, Keeva; McCallum, Lynn; Dyer, Hayder; McKeen, Hayley; Waugh, David; Roberts, Jennifer; McGregor, Joanne; Cotton, Graham; James, Iain; Harrison, Timothy; Hirst, David G.; Robson, Tracy

    2011-01-01

    Purpose Anti-angiogenic therapies can be an important adjunct to the management of many malignancies. Here we investigated a novel protein, FKBPL, and peptide derivative for their anti-angiogenic activity and mechanism of action. Experimental Design Recombinant FKBPL (rFKBPL) and its peptide derivative were assessed in a range of human microvascular endothelial cell (HMEC-1) assays in vitro. Their ability to inhibit proliferation, migration and Matrigel dependent tubule formation was determined. They were further evaluated in an ex-vivo rat model of neo-vascularisation and in two in vivo mouse models of angiogenesis; the sponge implantation and the intra-vital microscopy models. Anti-tumor efficacy was determined in two human tumor xenograft models grown in SCID mice. Finally, the dependence of peptide on CD44 was determined using a CD44 targeted siRNA approach or in cell lines of differing CD44 status. Results rFKBPL inhibited endothelial cell migration, tubule formation and microvessel formation in vitro and in vivo. The region responsible for FKBPL’s anti-angiogenic activity was identified and a 24 amino acid peptide (AD-01) spanning this sequence was synthesised. It was potently anti-angiogenic and inhibited growth in two human tumor xenograft models (DU145 and MDA-231) when administered systemically, either on its own, or in combination with docetaxel. The anti-angiogenic activity of FKBPL and AD-01 was dependent on the cell surface receptor CD44 and signalling downstream of this receptor promoted an anti-migratory phenotype. Conclusion FKBPL and its peptide derivative AD-01 have potent anti-angiogenic activity. Thus, these agents offer the potential of an attractive new approach to anti-angiogenic therapy. PMID:21364036

  12. Chondroprotective Effect of Kartogenin on CD44-Mediated Functions in Articular Cartilage and Chondrocytes

    PubMed Central

    Ono, Yohei; Ishizuka, Shinya; Knudson, Cheryl B.

    2014-01-01

    Objective: A recent report identified the small molecule kartogenin as a chondrogenic and chondroprotective agent. Since changes in hyaluronan metabolism occur during cartilage degeneration in osteoarthritis, we began studies to determine whether there was a connection between extracellular hyaluronan, CD44–hyaluronan interactions and the effects of kartogenin on articular chondrocytes. Methods: Chondrocytes cultured in monolayers, bioengineered neocartilages, or cartilage explants were treated with kartogenin with or without stimulation by IL-1β. Accumulation of matrix was visualized by a particle exclusion assay or by safranin O staining and release of sulfated glycosaminoglycans was determined. Production of aggrecanases and aggrecan G1-ITEGE neoepitope, fragmentation of CD44 and the SMAD1/5/8 signaling pathway were evaluated by western blotting. Results: Kartogenin treatment enhanced chondrocyte pericellular matrix assembly and retention in the presence of IL-1β. The chondroprotective effects of kartogenin on IL-1β-induced release of sulfated glycosaminoglycans from articular cartilage explants, reduction in safranin O staining of neocartilage discs as well as a reduction in aggrecan G1-ITEGE neoepitope in chondrocyte and explant cartilage cultures were observed. Kartogenin partially blocked the IL-1β-induced increased expression of ADAMTS-5. Additionally, kartogenin-treated articular chondrocytes exhibited a decrease in CD44 proteolytic fragmentation. However, kartogenin treatment did not enhance proteoglycan in control, non-IL-1β-treated cultures. Similarly, kartogenin enhanced the SMAD1 phosphorylation but only following pretreatment with IL-1β. Conclusion: These studies provide novel information on the chondroprotective function of kartogenin in adult articular cartilage. The effects of kartogenin are significant after activation of chondrocytic chondrolysis, which may occur following disruption of homeostasis maintained by hyaluronan–CD44

  13. Increased invasion and tumorigenicity capacity of CD44+/CD24- breast cancer MCF7 cells in vitro and in nude mice

    PubMed Central

    2013-01-01

    Background Identification of cancer stem cells (CSCs) and their behaviors will provide insightful information for the future control of human cancers. This study investigated CD44 and CD24 cell surface markers as breast cancer CSC markers in vitro and in vivo. Methods Flow cytometry with CD44 and CD24 markers was used to sort breast cancer MCF7 cells for scanning electron microscopy (SEM), tumor cell invasion assay, and nude mouse xenograft assay. Results Flow cytometry assay using CD44 and CD24 markers sorted MCF7 cells into four subsets, i.e., CD44+/CD24-/low, CD44-/CD24+, CD44+/CD24+, and CD44-/CD24-. The SEM data showed that there were many protrusions on the surface of CD44+/CD24-/low cells. CD44+/CD24-/low cells had many microvilli and pseudopodia. The CD44+/CD24-/low cells had a higher migration and invasion abilities than that of the other three subsets of the cells. The in vivo tumor formation assay revealed that CD44+/CD24- cells had the highest tumorigenic capacity compared to the other three subsets. Conclusion CD44 and CD24 could be useful markers for identification of breast CSCs because CD44+/CD24-/low cells had unique surface ultrastructures and the highest tumorigenicity and invasive abilities. PMID:23799994

  14. Relationship between the expression of versican and EGFR, HER-2, HER-3 and CD44 in matrix-producing tumours in the canine mammary gland.

    PubMed

    Damasceno, K A; Ferreira, E; Estrela-Lima, A; Bosco, Y; Silva, L P; Barros, A L B; Bertagnolli, A C; Cassali, G D

    2016-06-01

    Versican is an extracellular matrix proteoglycan that has been identified as a modulator of adhesion loss, cell motility, and tumour progression. This motility results from the interaction between versican and cell surface receptors. Studies have also demonstrated the relationship between this molecule and invasion in canine mammary tumours. Given the evidence for the participation of proteoglycans in tumour progression, this study aimed to assess versican expression and its association with cell surface receptors; human epidermal growth factor receptors 1, 2, and 3 (EGFR, HER-2, and HER-3) and CD44 through an immunohistochemical analysis of benign mixed tumours (BMTs), carcinomas in mixed tumours (CMTs), and carcinosarcomas (CSs) of the canine mammary gland. Malignant tumours were divided into low and high groups with respect to versican stromal expression. The results indicated that the BMTs showed weak stromal versican expression and correlations between the expression of stromal versican and EGFR in the epithelial membrane in benign areas (p=0.013, r=0.571). A higher stromal versican expression was observed adjacent to invasive epithelial areas compared with in situ areas in CMTs and CSs, suggesting a direct relationship between versican expression and invasiveness. Furthermore, the CSs exhibited a higher expression of HER-2, cytoplasmic HER-3, and CD44 in epithelial invasive cells in cases of higher stromal versican expression. Therefore, the cell surface receptors (HER-2, HER-3, and CD44) are more evident in CSs that overexpress versican in stroma adjacent to the invasive areas. These findings suggest that the association between these molecules may be directly related to the biological behaviour and invasiveness of these canine mammary tumours. PMID:26666308

  15. Deciphering the cellular source of tumor relapse identifies CD44 as a major therapeutic target in pancreatic adenocarcinoma

    PubMed Central

    Molejon, Maria Inés; Tellechea, Juan Ignacio; Loncle, Celine; Gayet, Odile; Gilabert, Marine; Duconseil, Pauline; Lopez-Millan, Maria Belen; Moutardier, Vincent; Gasmi, Mohamed; Garcia, Stephane; Turrini, Olivier; Ouaissi, Mehdi; Poizat, Flora; Dusetti, Nelson; Iovanna, Juan

    2015-01-01

    It has been commonly found that in patients presenting Pancreatic Ductal Adenocarcinoma (PDAC), after a period of satisfactory response to standard treatments, the tumor becomes non-responsive and patient death quickly follows. This phenomenon is mainly due to the rapid and uncontrolled development of the residual tumor. The origin and biological characteristics of residual tumor cells in PDAC still remain unclear. In this work, using PDACs from patients, preserved as xenografts in nude mice, we demonstrated that a residual PDAC tumor originated from a small number of CD44+ cells present in the tumor. During PDAC relapse, proliferating CD44+ cells decrease expression of ZEB1, while overexpressing the MUC1 protein, and gain morphological and biological characteristics of differentiation. Also, we report that CD44+ cells, in primary and residual PDAC tumors, are part of a heterogeneous population, which includes variable numbers of CD133+ and EpCAM+ cells. We confirmed the propagation of CD44+ cells in samples from cases of human relapse, following standard PDAC treatment. Finally, using systemic administration of anti-CD44 antibodies in vivo, we demonstrated that CD44 is an efficient therapeutic target for treating tumor relapse, but not primary PDAC tumors. We conclude that CD44+ cells generate the relapsing tumor and, as such, are themselves promising therapeutic targets for treating patients with recurrent PDAC. PMID:25797268

  16. Adhesion

    MedlinePlus

    ... adhesions Ovarian cyst References Munireddy S, Kavalukas SL, Barbul A. Intra-abdominal healing: gastrointestinal tract and adhesions. Surg Clin N Am Kulaylat MN, Dayton, MT. Surgical complications. In: Townsend CM Jr, Beauchamp RD, Evers BM, Mattox KL, ...

  17. Development of a sandwich enzyme-linked immunosorbent assay for the detection of CD44v3 using exon v3- and v6-specific monoclonal antibody pairs.

    PubMed

    Jeoung, Mee Hyun; Kim, Taek-Keun; Shim, Hyunbo; Lee, Sukmook

    2016-09-01

    It has been suggested that soluble CD44 levels in cancer patient sera may be closely associated with tumor progression and metastasis. However, to date, there has been limited methodology for detecting the soluble CD44 variant 3 isoform (CD44v3). Herein, using phage display technology, we isolated monoclonal antibodies specific to exon v3 or v6 of CD44 (CD44-exonv3 or CD44-exonv6) from a human synthetic antibody library. We also confirmed the specificity of antibody binding to CD44-exonv3 or -exonv6. Label-free kinetic analysis using the Octet biolayer interferometry system showed that the Kd values of the anti-CD44-exonv3 and anti-CD44-exonv6 antibodies for CD44v3-10 are approximately 1.1nM and 1.5nM, respectively. Finally, we developed a sandwich enzyme-linked immunosorbent assay (ELISA) using the anti-CD44-exonv3 and anti-CD44-exonv6 antibody pairs. The minimum detection limit of the assay was 6.2ng/ml CD44v3-10 and the linear range was up to 125ng/ml. Intra- and inter-assay coefficients of variation were 2.2% and 2.9%, respectively. The intra- and inter-assay recoveries were 99.3% and 105.3%, respectively. Taken together, these results suggest that this novel sandwich ELISA using the anti-CD44-exonv3 and anti-CD44-exonv6 antibody pairs will be useful for the detection of soluble CD44v3 in cancer patient sera. PMID:27288967

  18. ZDHHC3 Tyrosine Phosphorylation Regulates Neural Cell Adhesion Molecule Palmitoylation.

    PubMed

    Lievens, Patricia Marie-Jeanne; Kuznetsova, Tatiana; Kochlamazashvili, Gaga; Cesca, Fabrizia; Gorinski, Natalya; Galil, Dalia Abdel; Cherkas, Volodimir; Ronkina, Natalia; Lafera, Juri; Gaestel, Matthias; Ponimaskin, Evgeni; Dityatev, Alexander

    2016-09-01

    The neural cell adhesion molecule (NCAM) mediates cell-cell and cell-matrix adhesion. It is broadly expressed in the nervous system and regulates neurite outgrowth, synaptogenesis, and synaptic plasticity. Previous in vitro studies revealed that palmitoylation of NCAM is required for fibroblast growth factor 2 (FGF2)-stimulated neurite outgrowth and identified the zinc finger DHHC (Asp-His-His-Cys)-containing proteins ZDHHC3 and ZDHHC7 as specific NCAM-palmitoylating enzymes. Here, we verified that FGF2 controlled NCAM palmitoylation in vivo and investigated molecular mechanisms regulating NCAM palmitoylation by ZDHHC3. Experiments with overexpression and pharmacological inhibition of FGF receptor (FGFR) and Src revealed that these kinases control tyrosine phosphorylation of ZDHHC3 and that ZDHHC3 is phosphorylated by endogenously expressed FGFR and Src proteins. By site-directed mutagenesis, we found that Tyr18 is an FGFR1-specific ZDHHC3 phosphorylation site, while Tyr295 and Tyr297 are specifically phosphorylated by Src kinase in cell-based and cell-free assays. Abrogation of tyrosine phosphorylation increased ZDHHC3 autopalmitoylation, enhanced interaction with NCAM, and upregulated NCAM palmitoylation. Expression of ZDHHC3 with tyrosine mutated in cultured hippocampal neurons promoted neurite outgrowth. Our findings for the first time highlight that FGFR- and Src-mediated tyrosine phosphorylation of ZDHHC3 modulates ZDHHC3 enzymatic activity and plays a role in neuronal morphogenesis. PMID:27247265

  19. Cytoplasmic Tail Regulates the Intercellular Adhesion Function of the Epithelial Cell Adhesion Molecule

    PubMed Central

    Balzar, Maarten; Bakker, Hellen A. M.; Briaire-de-Bruijn, Inge H.; Fleuren, Gert Jan; Warnaar, Sven O.; Litvinov, Sergey V.

    1998-01-01

    Ep-CAM, an epithelium-specific cell-cell adhesion molecule (CAM) not structurally related to the major families of CAMs, contains a cytoplasmic domain of 26 amino acids. The chemical disruption of the actin microfilaments, but not of the microtubuli or intermediate filaments, affected the localization of Ep-CAM at the cell-cell boundaries, suggesting that the molecule interacts with the actin-based cytoskeleton. Mutated forms of Ep-CAM were generated with the cytoplasmic domain truncated at various lengths. All of the mutants were transported to the cell surface in the transfectants; however, the mutant lacking the complete cytoplasmic domain was not able to localize to the cell-cell boundaries, in contrast to mutants with partial deletions. Both the disruption of the actin microfilaments and a complete truncation of the cytoplasmic tail strongly affected the ability of Ep-CAM to mediate aggregation of L cells. The capability of direct aggregation was reduced for the partially truncated mutants but remained cytochalasin D sensitive. The tail truncation did not affect the ability of the transfectants to adhere to solid-phase-adsorbed Ep-CAM, suggesting that the ability to form stable adhesions and not the ligand specificity of the molecule was affected by the truncation. The formation of intercellular adhesions mediated by Ep-CAM induced a redistribution to the cell-cell boundaries of α-actinin, but not of vinculin, talin, filamin, spectrin, or catenins. Coprecipitation demonstrated direct association of Ep-CAM with α-actinin. Binding of α-actinin to purified mutated and wild-type Ep-CAMs and to peptides representing different domains of the cytoplasmic tail of Ep-CAM demonstrates two binding sites for α-actinin at positions 289 to 296 and 304 to 314 of the amino acid sequence. The results demonstrate that the cytoplasmic domain of Ep-CAM regulates the adhesion function of the molecule through interaction with the actin cytoskeleton via α-actinin. PMID:9671492

  20. Cytoplasmic tail regulates the intercellular adhesion function of the epithelial cell adhesion molecule.

    PubMed

    Balzar, M; Bakker, H A; Briaire-de-Bruijn, I H; Fleuren, G J; Warnaar, S O; Litvinov, S V

    1998-08-01

    Ep-CAM, an epithelium-specific cell-cell adhesion molecule (CAM) not structurally related to the major families of CAMs, contains a cytoplasmic domain of 26 amino acids. The chemical disruption of the actin microfilaments, but not of the microtubuli or intermediate filaments, affected the localization of Ep-CAM at the cell-cell boundaries, suggesting that the molecule interacts with the actin-based cytoskeleton. Mutated forms of Ep-CAM were generated with the cytoplasmic domain truncated at various lengths. All of the mutants were transported to the cell surface in the transfectants; however, the mutant lacking the complete cytoplasmic domain was not able to localize to the cell-cell boundaries, in contrast to mutants with partial deletions. Both the disruption of the actin microfilaments and a complete truncation of the cytoplasmic tail strongly affected the ability of Ep-CAM to mediate aggregation of L cells. The capability of direct aggregation was reduced for the partially truncated mutants but remained cytochalasin D sensitive. The tail truncation did not affect the ability of the transfectants to adhere to solid-phase-adsorbed Ep-CAM, suggesting that the ability to form stable adhesions and not the ligand specificity of the molecule was affected by the truncation. The formation of intercellular adhesions mediated by Ep-CAM induced a redistribution to the cell-cell boundaries of alpha-actinin, but not of vinculin, talin, filamin, spectrin, or catenins. Coprecipitation demonstrated direct association of Ep-CAM with alpha-actinin. Binding of alpha-actinin to purified mutated and wild-type Ep-CAMs and to peptides representing different domains of the cytoplasmic tail of Ep-CAM demonstrates two binding sites for alpha-actinin at positions 289 to 296 and 304 to 314 of the amino acid sequence. The results demonstrate that the cytoplasmic domain of Ep-CAM regulates the adhesion function of the molecule through interaction with the actin cytoskeleton via alpha

  1. Focal adhesion kinase-dependent focal adhesion recruitment of SH2 domains directs SRC into focal adhesions to regulate cell adhesion and migration

    PubMed Central

    Wu, Jui-Chung; Chen, Yu-Chen; Kuo, Chih-Ting; Wenshin Yu, Helen; Chen, Yin-Quan; Chiou, Arthur; Kuo, Jean-Cheng

    2015-01-01

    Directed cell migration requires dynamical control of the protein complex within focal adhesions (FAs) and this control is regulated by signaling events involving tyrosine phosphorylation. We screened the SH2 domains present in tyrosine-specific kinases and phosphatases found within FAs, including SRC, SHP1 and SHP2, and examined whether these enzymes transiently target FAs via their SH2 domains. We found that the SRC_SH2 domain and the SHP2_N-SH2 domain are associated with FAs, but only the SRC_SH2 domain is able to be regulated by focal adhesion kinase (FAK). The FAK-dependent association of the SRC_SH2 domain is necessary and sufficient for SRC FA targeting. When the targeting of SRC into FAs is inhibited, there is significant suppression of SRC-mediated phosphorylation of paxillin and FAK; this results in an inhibition of FA formation and maturation and a reduction in cell migration. This study reveals an association between FAs and the SRC_SH2 domain as well as between FAs and the SHP2_N-SH2 domains. This supports the hypothesis that the FAK-regulated SRC_SH2 domain plays an important role in directing SRC into FAs and that this SRC-mediated FA signaling drives cell migration. PMID:26681405

  2. Enrichment of CD44 in basal-type breast cancer correlates with EMT, cancer stem cell gene profile, and prognosis

    PubMed Central

    Xu, Hanxiao; Tian, Yijun; Yuan, Xun; Liu, Yu; Wu, Hua; Liu, Qian; Wu, Gen Sheng; Wu, Kongming

    2016-01-01

    Cluster of differentiation 44 (CD44) is a transmembrane glycoprotein that serves as the receptor for the extracellular matrix component hyaluronic acid. CD44 has been reported to play key roles in cell proliferation, motility, and survival, but its role in breast cancer remains controversial. In this study, we conducted a meta-analysis. A total of 23 published Gene Expression Omnibus databases were included to evaluate the association between CD44 mRNA expression and clinicopathological characteristics or prognosis of the patients with breast cancer. Our analysis revealed that CD44 expression was associated with clinicopathological features, including the histological grade, estrogen receptor status, progesterone receptor status, and human epidermal growth factor receptor-2 status. Higher levels of CD44 expression were observed in the basal subtype of breast cancer both at the mRNA and protein levels (odds ratio [OR] =2.08, 95% confidence interval [CI]: 1.72–2.52; OR =2.11, 95% CI: 1.67–2.68). Patients with CD44 overexpression exhibited significantly worse overall survival (hazard ratio =1.27; 95% CI: 1.04–1.55). Whole gene profile analysis revealed that CD44 expression was enriched in basal-type breast cancer and correlated with epithelial–mesenchymal transition and cancer stem cell gene profiles. In summary, our analyses indicated that CD44 potentially might be a prognostic marker for breast cancer and thus can serve as a therapeutic target for basal-type breast cancer. PMID:26855592

  3. CD44 promotes multi-drug resistance by protecting P-glycoprotein from FBXO21-mediated ubiquitination

    PubMed Central

    Ravindranath, Abhilash K.; Kaur, Swayamjot; Wernyj, Roman P.; Kumaran, Muthu N.; Miletti-Gonzalez, Karl E.; Chan, Rigel; Lim, Elaine; Madura, Kiran; Rodriguez-Rodriguez, Lorna

    2015-01-01

    Here we demonstrate that a ubiquitin E3-ligase, FBXO21, targets the multidrug resistance transporter, ABCB1, also known as P-glycoprotein (P-gp), for proteasomal degradation. We also show that the Ser291-phosphorylated form of the multifunctional protein and stem cell marker, CD44, inhibits FBXO21-directed degradation of P-gp. Thus, CD44 increases P-gp mediated drug resistance and represents a potential therapeutic target in P-gp-positive cells. PMID:26299618

  4. Evaluation of soluble CD44 splice variant v5 in the diagnosis and follow-up in breast cancer patients.

    PubMed

    Kittl, E M; Ruckser, R; Selleny, S; Samek, V; Hofmann, J; Huber, K; Reiner, A; Ogris, E; Hinterberger, W; Bauer, K

    1997-01-01

    Aberrant expression of CD44 splice variants has been detected on a variety of human tumor cells. Overexpression of specific isoforms has been shown to be associated with metastasis and poor prognosis in breast cancer. We evaluated the possible utility of soluble CD44 splice variant v5 (sCD44v5) as a circulating, tumor-associated marker in breast cancer patients. Serum levels of sCD44v5 were determined in 147 healthy volunteers, in 53 patients with nonmalignant breast disease, in 85 patients with breast cancer at presentation, in 13 patients with recurrence and in 73 patients with active metastatic disease. Statistically, the levels at presentation in stages I-IV, in benign disease, and in a female control group were not significantly different. First longitudinal studies over 1-2 years in the follow-up of 28 patients who have remained tumor-free showed considerable between-patient variation while the intrapatient levels remained within relatively narrow limits. In patients with active metastatic disease, elevated levels of sCD44v5 (> 58 ng.ml-1) were detected in 50% of the cases with marked elevation in only 26%. In these cases, sCD44v5 correlated with the extent of metastatic disease and fell during clinical response to cytoreductive therapy. In comparison with CA15-3 in the patients' follow-up serum levels of sCD44v5 proved to be much less sensitive concerning lead time, percentage of raised serum levels at the time of recurrence and in metastatic disease. The value of sCD44v5 determinations in breast cancer patients was further limited by the poor diagnostic specificity of this marker due to elevated levels in smokers and chronic inflammatory disease. PMID:9523162

  5. Dynamic Regulation of Activated Leukocyte Cell Adhesion Molecule–mediated Homotypic Cell Adhesion through the Actin CytoskeletonV⃞

    PubMed Central

    Nelissen, Judith M. D. T.; Peters, Inge M.; de Grooth, Bart G.; van Kooyk, Yvette; Figdor, Carl G.

    2000-01-01

    Restricted expression of activated leukocyte cell adhesion molecule (ALCAM) by hematopoietic cells suggests an important role in the immune system and hematopoiesis. To get insight into the mechanisms that control ALCAM-mediated adhesion we have investigated homotypic ALCAM–ALCAM interactions. Here, we demonstrate that the cytoskeleton regulates ALCAM-mediated cell adhesion because inhibition of actin polymerization by cytochalasin D (CytD) strongly induces homotypic ALCAM–ALCAM interactions. This induction of cell adhesion is likely due to clustering of ALCAM at the cell surface, which is observed after CytD treatment. Single-particle tracking demonstrated that the lateral mobility of ALCAM in the cell membrane is increased 30-fold after CytD treatment. In contrast, both surface distribution and adhesion of a glycosylphosphatidylinositol (GPI)-anchored ALCAM mutant are insensitive to CytD, despite the increase in lateral mobility of GPI-ALCAM upon CytD treatment. This demonstrates that clustering of ALCAM is essential for cell adhesion, whereas enhanced diffusion of ALCAM alone is not sufficient for cluster formation. In addition, upon ligand binding, both free diffusion and the freely dragged distance of wild-type ALCAM, but not of GPI-ALCAM, are reduced over time, suggesting strengthening of the cytoskeleton linkage. From these findings we conclude that activation of ALCAM-mediated adhesion is dynamically regulated through actin cytoskeleton-dependent clustering. PMID:10848629

  6. Stro-1/CD44 as putative human myometrial and fibroid stem cell markers

    PubMed Central

    Mas, Aymara; Nair, Sangeeta; Laknaur, Archana; Simón, Carlos; Diamond, Michael P.; Al-Hendy, Ayman

    2015-01-01

    Objective To identify and characterize myometrial/fibroid stem cells by specific stem cell markers in human myometrium, and to better understand the stem cell contribution in the development of uterine fibroids. Design Prospective experimental human and animal study. Setting University research laboratory. Patients Women undergoing hysterectomy for treatment of symptomatic uterine fibroids. Animals Female NOD/SCID/IL-2Rγnull mice. Interventions Identification and isolation of stem cells from human fibroids (F) and adjacent myometrium (MyoF) tissues using Stro-1/CD44 specific surface markers. Main Outcome Measures Flow cytometry, semi- quantitative polymerase chain reaction, clonogenicity assays, cell culture, molecular analysis, immunocyto- histochemistry, in vitro differentiation, and xenotransplantation assays. Results Using Stro-1/CD44 surface markers, we were able to isolate stem cells from MyoF and F tissues. The undifferentiated status of isolated cells was confirmed by the expression of ABCG2 transporter, as well as additional stem cell markers OCT4, NANOG and GDB3, and the low expression of steroid receptors ERα and PR-A/PR-B. Mesodermal cell origin was established by the presence of typical mesenchymal markers (CD90, CD105, and CD73) and absence of hematopoietic stem cell markers (CD34, CD45), and confirmed by the ability of these cells to differentiate in vitro into adipocytes, osteocytes and chondrocytes. Finally, their functional capability to form fibroid-like lesions was established in xenotransplantation mouse model. The injected cells labeled with superparamagnetic iron oxide (SPIO) were tracked by both magnetic resonance imaging (MRI) and fluorescence imaging, thus demonstrating the regenerative potential of putative fibroid stem cells in vivo. Conclusion We have demonstrated that Stro-1/CD44 can be used as specific surface markers to enrich a subpopulation of myometrial/fibroids cells, exhibiting key features of stem/progenitor cells. These

  7. The Interplay of Antigen Affinity, Internalization, and Pharmacokinetics on CD44-Positive Tumor Targeting of Monoclonal Antibodies.

    PubMed

    Glatt, Dylan M; Beckford Vera, Denis R; Parrott, Matthew C; Luft, J Christopher; Benhabbour, S Rahima; Mumper, Russell J

    2016-06-01

    Monoclonal antibodies (mAbs) offer promise as effective tumor targeting and drug delivery agents for cancer therapy. However, comparative biological and clinical characteristics of mAbs targeting the same tumor-associated antigen (TAA) often differ widely. This study examined the characteristics of mAbs that impact tumor targeting using a panel of mAb clones specific to the cancer-associated cell-surface receptor and cancer stem cell marker CD44. CD44 mAbs were screened for cell-surface binding, antigen affinity, internalization, and CD44-mediated tumor uptake by CD44-positive A549 cells. It was hypothesized that high-affinity, rapidly internalizing CD44 mAbs would result in high tumor uptake and prolonged tumor retention. Although high-affinity clones rapidly bound and were internalized by A549 cells in vitro, an intermediate-affinity clone demonstrated significantly greater tumor uptake and retention than high-affinity clones in vivo. Systemic exposure, rather than high antigen affinity or rapid internalization, best associated with tumor targeting of CD44 mAbs in A549 tumor-bearing mice. PMID:27079967

  8. Lipid-Based Nanovectors for Targeting of CD44-Overexpressing Tumor Cells

    PubMed Central

    Fattal, Elias

    2013-01-01

    Hyaluronic acid (HA) is a naturally occurring glycosaminoglycan that exists in living systems, and it is a major component of the extracellular matrix. The hyaluronic acid receptor CD44 is found at low levels on the surface of epithelial, haematopoietic, and neuronal cells and is overexpressed in many cancer cells particularly in tumour initiating cells. HA has been therefore used as ligand attached to HA-lipid-based nanovectors for the active targeting of small or large active molecules for the treatment of cancer. This paper describes the different approaches employed for the preparation, characterization, and evaluation of these potent delivery systems. PMID:23533773

  9. Tropomyosin 4 regulates adhesion structures and resorptive capacity in osteoclasts.

    PubMed

    McMichael, Brooke K; Lee, Beth S

    2008-02-01

    Tropomyosins (Tms) are alpha-helical dimers that bind and stabilize actin microfilaments while regulating their accessibility to other actin-associated proteins. Four genes encode expression of over forty Tms, most of which are expressed in nonmuscle cells. In recent years, it has become clear that individual Tm isoforms may regulate specific actin pools within cells. In this study, we examined how osteoclast function may be regulated by the tropomyosin isoform Tm-4, which we previously showed to be highly localized to podosomes and sealing zones of osteoclasts. RNAi-mediated knockdown of Tm-4, both in RAW264.7- and mouse marrow-derived osteoclasts, resulted in thinning of the actin ring of the sealing zone. Knockdown of Tm-4 also resulted in diminished bone resorptive capacity and altered resorption pit shape. In contrast, osteoclasts overexpressing Tm-4 demonstrated thickened podosomes on glass as well as thickened, aberrant actin structures on bone, and diminished motility and resorptive capacity. These results indicate that Tm-4 plays a role in regulating adhesion structures of osteoclasts, most likely by stabilizing the actin microfilaments present in podosomes and the sealing zone. PMID:18036591

  10. Generation of CD44 gene-deficient mouse derived induced pluripotent stem cells: CD44 gene-deficient iPSCs.

    PubMed

    Song, Zhenwei; Ji, Qianqian; Zhao, Haijing; Nie, Yu; He, Zuyong; Chen, Yaosheng; Cong, Peiqing

    2014-10-01

    Induced pluripotent stem cells (iPSCs) show good promise for the treatment of defects caused by numerous genetic diseases. Herein, we successfully generated CD44 gene-deficient iPSCs using Oct4, Sox2, Klf4, and vitamin C. The generated iPSCs displayed a characteristic morphology similar to the well-characterized embryonic stem cells. Alkaline phosphatase, cell surface (SSEA1, NANOG, and OCT4), and pluripotency markers were expressed at high levels in these cells. The iPSCs formed teratomas in vivo and supported full-term development of constructed porcine embryos by inter-species nuclear transplantation. Importantly, incubation with trichostatin A increased the efficiency of iPSCs generation by increasing the histone acetylation levels. Moreover, more iPSCs colonies appeared following cell passaging during colony picking, thus increasing the effectiveness of iPSCs selection. Thus, our work provides essential stem cell materials for the treatment of genetic diseases and proposes a novel strategy to enhance the efficiency of induced reprogramming. PMID:24952030

  11. Macrophage-Associated Osteoactivin/GPNMB Mediates Mesenchymal Stem Cell Survival, Proliferation, and Migration Via a CD44-Dependent Mechanism.

    PubMed

    Yu, Bing; Sondag, Gregory R; Malcuit, Christopher; Kim, Min-Ho; Safadi, Fayez F

    2016-07-01

    Although MSCs have been widely recognized to have therapeutic potential in the repair of injured or diseased tissues, it remains unclear how functional activities of mesenchymal stem cells (MSCs) are influenced by the surrounding inflammatory milieu at the site of tissue injury. Macrophages constitute an essential component of innate immunity and have been shown to exhibit a phenotypic plasticity in response to various stimuli, which play a central role in both acute inflammation and wound repair. Osteoactivin (OA)/Glycoprotein non-metastatic melanoma protein B (GPNMB), a transmembrane glycoprotein that plays a role in cell differentiation, survival, and angiogenesis. The objective of this study was to investigate the potential role of OA/GPNMB in macrophage-induced MSC function. We found that reparative M2 macrophages express significantly greater levels of OA/GPNMB than pro-inflammatory M1 macrophages. Furthermore, using loss of function and rescue studies, we demonstrated that M2 macrophages-secreted OA/GPNMB positively regulates the viability, proliferation, and migration of MSCs. More importantly, we demonstrated that OA/GPNMB acts through ERK and AKT signaling pathways in MSCs via CD44, to induce these effects. Taken together, our results provide pivotal insight into the mechanism by which OA/GPNMB contributes to the tissue reparative phenotype of M2 macrophages and positively regulates functional activities of MSCs. J. Cell. Biochem. 117: 1511-1521, 2016. © 2015 Wiley Periodicals, Inc. PMID:26442636

  12. CD44 is a Marker for the Outer Pillar Cells in the Early Postnatal Mouse Inner Ear

    PubMed Central

    Puligilla, Chandrakala; Chan, Siaw-Lin; Timothy, Caroline; Depireux, Didier A.; Ahmed, Zubair; Wolf, Jeffrey; Eisenman, David J.; Friedman, Thomas B.; Riazuddin, Sheikh; Kelley, Matthew W.; Strome, Scott E.

    2010-01-01

    Cluster of differentiation antigens (CD proteins) are classically used as immune cell markers. However, their expression within the inner ear is still largely undefined. In this study, we explored the possibility that specific CD proteins might be useful for defining inner ear cell populations. mRNA expression profiling of microdissected auditory and vestibular sensory epithelia revealed 107 CD genes as expressed in the early postnatal mouse inner ear. The expression of 68 CD genes was validated with real-time RT-PCR using RNA extracted from microdissected sensory epithelia of cochleae, utricles, saccules, and cristae of newborn mice. Specifically, CD44 was identified as preferentially expressed in the auditory sensory epithelium. Immunohistochemistry revealed that within the early postnatal organ of Corti, the expression of CD44 is restricted to outer pillar cells. In order to confirm and expand this finding, we characterized the expression of CD44 in two different strains of mice with loss- and gain-of-function mutations in Fgfr3 which encodes a receptor for FGF8 that is essential for pillar cell development. We found that the expression of CD44 is abolished from the immature pillar cells in homozygous Fgfr3 knockout mice. In contrast, both the outer pillar cells and the aberrant Deiters’ cells in the Fgfr3P244R/+ mice express CD44. The deafness phenotype segregating in DFNB51 families maps to a linkage interval that includes CD44. To study the potential role of CD44 in hearing, we characterized the auditory system of CD44 knockout mice and sequenced the entire open reading frame of CD44 of affected members of DFNB51 families. Our results suggest that CD44 does not underlie the deafness phenotype of the DFNB51 families. Finally, our study reveals multiple potential new cell type-specific markers in the mouse inner ear and identifies a new marker for outer pillar cells. Electronic supplementary material The online version of this article (doi:10.1007/s10162

  13. Transforming Growth Factor-β1 (TGF-β1)-stimulated Fibroblast to Myofibroblast Differentiation Is Mediated by Hyaluronan (HA)-facilitated Epidermal Growth Factor Receptor (EGFR) and CD44 Co-localization in Lipid Rafts*

    PubMed Central

    Midgley, Adam C.; Rogers, Mathew; Hallett, Maurice B.; Clayton, Aled; Bowen, Timothy; Phillips, Aled O.; Steadman, Robert

    2013-01-01

    Fibroblast to myofibroblast differentiation drives effective wound healing and is largely regulated by the cytokine transforming growth factor-β1 (TGF-β1). Myofibroblasts express α-smooth muscle actin and are present in granulation tissue, where they are responsible for wound contraction. Our previous studies show that fibroblast differentiation in response to TGF-β1 is dependent on and mediated by the linear polysaccharide hyaluronan (HA). Both the HA receptor, CD44, and the epidermal growth factor receptor (EGFR) are involved in this differentiation response. The aim of this study was to understand the mechanisms linking HA-, CD44-, and EGFR-regulated TGF-β1-dependent differentiation. CD44 and EGFR co-localization within membrane-bound lipid rafts was necessary for differentiation, and this triggered downstream mitogen-activated protein kinase (MAPK/ERK) and Ca2+/calmodulin kinase II (CaMKII) activation. We also found that ERK phosphorylation was upstream of CaMKII phosphorylation, that ERK activation was necessary for CaMKII signaling, and that both kinases were essential for differentiation. In addition, HA synthase-2 (HAS2) siRNA attenuated both ERK and CaMKII signaling and sequestration of CD44 into lipid rafts, preventing differentiation. In summary, the data suggest that HAS2-dependent production of HA facilitates TGF-β1-dependent fibroblast differentiation through promoting CD44 interaction with EGFR held within membrane-bound lipid rafts. This induces MAPK/ERK, followed by CaMKII activation, leading to differentiation. This pathway is synergistic with the classical TGF-β1-dependent SMAD-signaling pathway and may provide a novel opportunity for intervention in wound healing. PMID:23589287

  14. CADM1 Controls Actin Cytoskeleton Assembly and Regulates Extracellular Matrix Adhesion in Human Mast Cells

    PubMed Central

    Moiseeva, Elena P.; Straatman, Kees R.; Leyland, Mark L.; Bradding, Peter

    2014-01-01

    CADM1 is a major receptor for the adhesion of mast cells (MCs) to fibroblasts, human airway smooth muscle cells (HASMCs) and neurons. It also regulates E-cadherin and alpha6beta4 integrin in other cell types. Here we investigated a role for CADM1 in MC adhesion to both cells and extracellular matrix (ECM). Downregulation of CADM1 in the human MC line HMC-1 resulted not only in reduced adhesion to HASMCs, but also reduced adhesion to their ECM. Time-course studies in the presence of EDTA to inhibit integrins demonstrated that CADM1 provided fast initial adhesion to HASMCs and assisted with slower adhesion to ECM. CADM1 downregulation, but not antibody-dependent CADM1 inhibition, reduced MC adhesion to ECM, suggesting indirect regulation of ECM adhesion. To investigate potential mechanisms, phosphotyrosine signalling and polymerisation of actin filaments, essential for integrin-mediated adhesion, were examined. Modulation of CADM1 expression positively correlated with surface KIT levels and polymerisation of cortical F-actin in HMC-1 cells. It also influenced phosphotyrosine signalling and KIT tyrosine autophosphorylation. CADM1 accounted for 46% of surface KIT levels and 31% of F-actin in HMC-1 cells. CADM1 downregulation resulted in elongation of cortical actin filaments in both HMC-1 cells and human lung MCs and increased cell rigidity of HMC-1 cells. Collectively these data suggest that CADM1 is a key adhesion receptor, which regulates MC net adhesion, both directly through CADM1-dependent adhesion, and indirectly through the regulation of other adhesion receptors. The latter is likely to occur via docking of KIT and polymerisation of cortical F-actin. Here we propose a stepwise model of adhesion with CADM1 as a driving force for net MC adhesion. PMID:24465823

  15. Molecular Imaging of CD44-Overexpressing Gastric Cancer in Mice Using T2 MR Imaging.

    PubMed

    Lee, Hwunjae; Yang, Seung-Hyun; Heo, Dan; Son, Heyoung; Haam, Seungjoo; Suh, Jin-Suck; Yang, Jaemoon; Huh, Yong-Min

    2016-01-01

    Novel diagnostic techniques have been developed in many research area using targetable contrast agents with magnetic resonance imaging (MRI) for cancer diagnosis. For cancer diagnosis, the use of MRI with biocompatible targeting moieties and manganese ferrite nanoparticles (MFNPs) is preferred. Thus, we synthesized MFNPs using a thermal decomposition method which enables sensitive T2 or T2 Turbo Spin Echo (TSE) MRI and coated them with hyaluronic acid (HA). The high targeting ability of HA-MFNPs was observed at MKN-45 cells (gastric cancer cell line) which high-expressing CD44 in contrast with MKN-28 cells which low-expressing CD44. We also prepared the gastric cancer mice model using MKN-45 cells which has the stem-like property was implanted into BALB/c nude mice. And then HA-MFNPs of the T2 contrast enhancement effects and targeting ability were investigated by in vivo MR imaging. As a result of these studies, we conclude that HA coated MFNPs can be effectively used as a novel probes for visualizing gastric cancer stem cells. PMID:27398445

  16. Dual CD44 and folate receptor-targeted nanoparticles for cancer diagnosis and anticancer drug delivery.

    PubMed

    Lee, Jae-Young; Termsarasab, Ubonvan; Park, Ju-Hwan; Lee, Song Yi; Ko, Seung-Hak; Shim, Jae-Seong; Chung, Suk-Jae; Cho, Hyun-Jong; Kim, Dae-Duk

    2016-08-28

    Dual CD44 and folate receptor targetable nanoparticles (NPs) based on hyaluronic acid-ceramide-folic acid (HACE-FA) were fabricated for improving tumor targetability. HACE-FA was synthesized via esterification between the carboxylic group of FA and hydroxyl group of HA. Doxorubicin (DOX)-loaded HACE-FA NPs, with a mean diameter of 120-130nm, narrow size distribution, and negative zeta potential, were prepared. The drug release from HACE-FA NPs were significantly increased in acidic pH (pH5.5) compared with physiological pH (7.4) (p<0.05). The cellular accumulation of the drug in HACE-FA NPs group was higher than that of HACE NPs group in SKOV-3 cells (human ovarian cancer cells; CD44 and folate receptor (FR)-positive cells). Dual targetability of HACE-FA NPs, compared to HACE NPs, was also verified in the SKOV-3 tumor-xenografted mouse model by near-infrared fluorescence (NIRF) imaging. Twenty-four hours after injection, HACE-FA NPs were accumulated mainly in tumor regions and their fluorescence intensity was 4.82-fold higher than that of HACE NPs (p<0.05). These findings suggest successful application of HACE-FA NPs for the accurate delivery of anticancer drugs to ovarian cancer. PMID:27320169

  17. Hyaluronic acid modified mesoporous silica nanoparticles for targeted drug delivery to CD44-overexpressing cancer cells

    NASA Astrophysics Data System (ADS)

    Yu, Meihua; Jambhrunkar, Siddharth; Thorn, Peter; Chen, Jiezhong; Gu, Wenyi; Yu, Chengzhong

    2012-12-01

    In this paper, a targeted drug delivery system has been developed based on hyaluronic acid (HA) modified mesoporous silica nanoparticles (MSNs). HA-MSNs possess a specific affinity to CD44 over-expressed on the surface of a specific cancer cell line, HCT-116 (human colon cancer cells). The cellular uptake performance of fluorescently labelled MSNs with and without HA modification has been evaluated by confocal microscopy and fluorescence-activated cell sorter (FACS) analysis. Compared to bare MSNs, HA-MSNs exhibit a higher cellular uptake via HA receptor mediated endocytosis. An anticancer drug, doxorubicin hydrochloride (Dox), has been loaded into MSNs and HA-MSNs as drug delivery vehicles. Dox loaded HA-MSNs show greater cytotoxicity to HCT-116 cells than free Dox and Dox-MSNs due to the enhanced cell internalization behavior of HA-MSNs. It is expected that HA-MSNs have a great potential in targeted delivery of anticancer drugs to CD44 over-expressing tumors.

  18. Hyaluronic acid modified mesoporous carbon nanoparticles for targeted drug delivery to CD44-overexpressing cancer cells.

    PubMed

    Wan, Long; Jiao, Jian; Cui, Yu; Guo, Jingwen; Han, Ning; Di, Donghua; Chang, Di; Wang, Pu; Jiang, Tongying; Wang, Siling

    2016-04-01

    In this paper, hyaluronic acid (HA) functionalized uniform mesoporous carbon spheres (UMCS) were synthesized for targeted enzyme responsive drug delivery using a facile electrostatic attraction strategy. This HA modification ensured stable drug encapsulation in mesoporous carbon nanoparticles in an extracellular environment while increasing colloidal stability, biocompatibility, cell-targeting ability, and controlled cargo release. The cellular uptake experiments of fluorescently labeled mesoporous carbon nanoparticles, with or without HA functionalization, demonstrated that HA-UMCS are able to specifically target cancer cells overexpressing CD44 receptors. Moreover, the cargo loaded doxorubicin (DOX) and verapamil (VER) exhibited a dual pH and hyaluronidase-1 responsive release in the tumor microenvironment. In addition, VER/DOX/HA-UMCS exhibited a superior therapeutic effect on an in vivo HCT-116 tumor in BALB/c nude mice. In summary, it is expected that HA-UMCS will offer a new method for targeted co-delivery of drugs to tumors overexpressing CD44 receptors. PMID:26901756

  19. Light-triggered in vivo activation of adhesive peptides regulates cell adhesion, inflammation and vascularization of biomaterials

    NASA Astrophysics Data System (ADS)

    Lee, Ted T.; García, José R.; Paez, Julieta I.; Singh, Ankur; Phelps, Edward A.; Weis, Simone; Shafiq, Zahid; Shekaran, Asha; Del Campo, Aránzazu; García, Andrés J.

    2015-03-01

    Materials engineered to elicit targeted cellular responses in regenerative medicine must display bioligands with precise spatial and temporal control. Although materials with temporally regulated presentation of bioadhesive ligands using external triggers, such as light and electric fields, have recently been realized for cells in culture, the impact of in vivo temporal ligand presentation on cell-material responses is unknown. Here, we present a general strategy to temporally and spatially control the in vivo presentation of bioligands using cell-adhesive peptides with a protecting group that can be easily removed via transdermal light exposure to render the peptide fully active. We demonstrate that non-invasive, transdermal time-regulated activation of cell-adhesive RGD peptide on implanted biomaterials regulates in vivo cell adhesion, inflammation, fibrous encapsulation, and vascularization of the material. This work shows that triggered in vivo presentation of bioligands can be harnessed to direct tissue reparative responses associated with implanted biomaterials.

  20. Light-triggered in vivo activation of adhesive peptides regulates cell adhesion, inflammation and vascularization of biomaterials.

    PubMed

    Lee, Ted T; García, José R; Paez, Julieta I; Singh, Ankur; Phelps, Edward A; Weis, Simone; Shafiq, Zahid; Shekaran, Asha; Del Campo, Aránzazu; García, Andrés J

    2015-03-01

    Materials engineered to elicit targeted cellular responses in regenerative medicine must display bioligands with precise spatial and temporal control. Although materials with temporally regulated presentation of bioadhesive ligands using external triggers, such as light and electric fields, have recently been realized for cells in culture, the impact of in vivo temporal ligand presentation on cell-material responses is unknown. Here, we present a general strategy to temporally and spatially control the in vivo presentation of bioligands using cell-adhesive peptides with a protecting group that can be easily removed via transdermal light exposure to render the peptide fully active. We demonstrate that non-invasive, transdermal time-regulated activation of cell-adhesive RGD peptide on implanted biomaterials regulates in vivo cell adhesion, inflammation, fibrous encapsulation, and vascularization of the material. This work shows that triggered in vivo presentation of bioligands can be harnessed to direct tissue reparative responses associated with implanted biomaterials. PMID:25502097

  1. Light-triggered in vivo Activation of Adhesive Peptides Regulates Cell Adhesion, Inflammation and Vascularization of Biomaterials

    PubMed Central

    Lee, Ted T.; García, José R.; Paez, Julieta; Singh, Ankur; Phelps, Edward A.; Weis, Simone; Shafiq, Zahid; Shekaran, Asha; del Campo, Aránzazu; García, Andrés J.

    2014-01-01

    Materials engineered to elicit targeted cellular responses in regenerative medicine must display bioligands with precise spatial and temporal control. Although materials with temporally regulated presentation of bioadhesive ligands using external triggers, such as light and electric fields, have been recently realized for cells in culture, the impact of in vivo temporal ligand presentation on cell-material responses is unknown. Here, we present a general strategy to temporally and spatially control the in vivo presentation of bioligands using cell adhesive peptides with a protecting group that can be easily removed via transdermal light exposure to render the peptide fully active. We demonstrate that non-invasive, transdermal time-regulated activation of cell-adhesive RGD peptide on implanted biomaterials regulates in vivo cell adhesion, inflammation, fibrous encapsulation, and vascularization of the material. This work shows that triggered in vivo presentation of bioligands can be harnessed to direct tissue reparative responses associated with implanted biomaterials. PMID:25502097

  2. Low molecular weight hyaluronan mediated CD44 dependent induction of IL-6 and chemokines in human dermal fibroblasts potentiates innate immune response.

    PubMed

    Vistejnova, Lucie; Safrankova, Barbora; Nesporova, Kristina; Slavkovsky, Rastislav; Hermannova, Martina; Hosek, Petr; Velebny, Vladimir; Kubala, Lukas

    2014-12-01

    Complex regulation of the wound healing process involves multiple interactions among stromal tissue cells, inflammatory cells, and the extracellular matrix. Low molecular weight hyaluronan (LMW HA) derived from the degradation of high molecular weight hyaluronan (HMW HA) is suggested to activate cells involved in wound healing through interaction with HA receptors. In particular, receptor CD44 is suggested to mediate cell response to HA of different MW, being the main cell surface HA receptor in stromal tissue and immune cells. However, the response of dermal fibroblasts, the key players in granulation tissue formation within the wound healing process, to LMW HA and their importance for the activation of immune cells is unclear. In this study we show that LMW HA (4.3kDa) induced pro-inflammatory cytokine IL-6 and chemokines IL-8, CXCL1, CXCL2, CXCL6 and CCL8 gene expression in normal human dermal fibroblasts (NHDF) that was further confirmed by increased levels of IL-6 and IL-8 in cell culture supernatants. Conversely, NHDF treated by HMW HA revealed a tendency to decrease the gene expression of these cytokine and chemokines when compared to untreated control. The blockage of CD44 expression by siRNA resulted in the attenuation of IL-6 and chemokines expression in LMW HA treated NHDF suggesting the involvement of CD44 in LMW HA mediated NHDF activation. The importance of pro-inflammatory mediators produced by LMW HA triggered NHDF was evaluated by significant activation of blood leukocytes exhibited as increased production of IL-6 and TNF-α. Conclusively, we demonstrated a pro-inflammatory response of dermal fibroblasts to LMW HA that was transferred to leukocytes indicating the significance of LMW HA in the inflammatory process development during the wound healing process. PMID:25126764

  3. Nanovesicle-mediated systemic delivery of microRNA-34a for CD44 overexpressing gastric cancer stem cell therapy.

    PubMed

    Jang, Eunji; Kim, Eunjung; Son, Hye-Young; Lim, Eun-Kyung; Lee, Hwunjae; Choi, Yuna; Park, Kwangyeol; Han, Seungmin; Suh, Jin-Suck; Huh, Yong-Min; Haam, Seungjoo

    2016-10-01

    The cancer stem cell (CSC) hypothesis postulates that cancer cells overexpressing CD44 are marked as CSCs that cause tumorigenesis and recurrence. This hypothesis suggests that CD44 is a potential therapeutic target that can interfere with CSCs qualities. MicroRNA-34a (miR-34a) is a promising candidate for CD44 repression-based cancer therapy as it has been reported to inhibit proliferation, metastasis, and survival of CD44-positive CSCs. Here, we used nanovesicles containing PLI/miR complexes (NVs/miR) to systemically deliver miR-34a and induce miR-34a-triggered CD44 suppression in orthotopically and subcutaneously implanted tumors in nude mice. Poly(l-lysine-graft-imidazole) (PLI) condenses miRs and is functionally modified to deliver miRs to the site of action by buffering effect of imidazole residues under endosomal pH. Indeed, NVs/miR consisting of PEGylated lipids enveloping PLI/miR complexes greatly reduced inevitable toxicity of polycations by compensating their surface charge and markedly improved their in vivo stability and accumulation to tumor tissue compared to PLI/miR polyplexes. Our NVs-mediated miR-34a delivery system specifically increased endogenous target miR levels, thereby attenuating proliferation and migration of gastric cancer cells by repressing the expression of CD44 with decreased levels of Bcl-2, Oct 3/4 and Nanog genes. Our strategy led to a greater therapeutic outcome than PLI-based delivery with highly selective tumor cell death and significantly delayed tumor growth in CD44-positive tumor-bearing mouse models, thus providing a fundamental therapeutic window for CSCs. PMID:27497057

  4. Tbx1 regulates oral epithelial adhesion and palatal development

    PubMed Central

    Funato, Noriko; Nakamura, Masataka; Richardson, James A.; Srivastava, Deepak; Yanagisawa, Hiromi

    2012-01-01

    Cleft palate, the most frequent congenital craniofacial birth defect, is a multifactorial condition induced by the interaction of genetic and environmental factors. In addition to complete cleft palate, a large number of human cases involve soft palate cleft and submucosal cleft palate. However, the etiology of these forms of cleft palate has not been well understood. T-box transcriptional factor (Tbx) family of transcriptional factors has distinct roles in a wide range of embryonic differentiation or response pathways. Here, we show that genetic disruption of Tbx1, a major candidate gene for the human congenital disorder 22q11.2 deletion syndrome (Velo-cardio-facial/DiGeorge syndrome), led to abnormal epithelial adhesion between the palate and mandible in mouse, resulting in various forms of cleft palate similar to human conditions. We found that hyperproliferative epithelium failed to undergo complete differentiation in Tbx1-null mice (Tbx1−/−). Inactivation of Tbx1 specifically in the keratinocyte lineage (Tbx1KCKO) resulted in an incomplete cleft palate confined to the anterior region of the palate. Interestingly, Tbx1 overexpression resulted in decreased cell growth and promoted cell-cycle arrest in MCF7 epithelial cells. These findings suggest that Tbx1 regulates the balance between proliferation and differentiation of keratinocytes and is essential for palatal fusion and oral mucosal differentiation. The impaired adhesion separation of the oral epithelium together with compromised palatal mesenchymal growth is an underlying cause for various forms of cleft palate phenotypes in Tbx1−/− mice. Our present study reveals new pathogenesis of incomplete and submucous cleft palate during mammalian palatogenesis. PMID:22371266

  5. CLIC4 regulates cell adhesion and β1 integrin trafficking.

    PubMed

    Argenzio, Elisabetta; Margadant, Coert; Leyton-Puig, Daniela; Janssen, Hans; Jalink, Kees; Sonnenberg, Arnoud; Moolenaar, Wouter H

    2014-12-15

    Chloride intracellular channel protein 4 (CLIC4) exists in both soluble and membrane-associated forms, and is implicated in diverse cellular processes, ranging from ion channel formation to intracellular membrane remodeling. CLIC4 is rapidly recruited to the plasma membrane by lysophosphatidic acid (LPA) and serum, suggesting a possible role for CLIC4 in exocytic-endocytic trafficking. However, the function and subcellular target(s) of CLIC4 remain elusive. Here, we show that in HeLa and MDA-MB-231 cells, CLIC4 knockdown decreases cell-matrix adhesion, cell spreading and integrin signaling, whereas it increases cell motility. LPA stimulates the recruitment of CLIC4 to β1 integrin at the plasma membrane and in Rab35-positive endosomes. CLIC4 is required for both the internalization and the serum- or LPA-induced recycling of β1 integrin, but not for EGF receptor trafficking. Furthermore, we show that CLIC4 suppresses Rab35 activity and antagonizes Rab35-dependent regulation of β1 integrin trafficking. Our results define CLIC4 as a regulator of Rab35 activity and serum- and LPA-dependent integrin trafficking. PMID:25344254

  6. PACSIN2 regulates cell adhesion during gastrulation in Xenopus laevis.

    PubMed

    Cousin, Hélène; Desimone, Douglas W; Alfandari, Dominique

    2008-07-01

    We previously identified the adaptor protein PACSIN2 as a negative regulator of ADAM13 proteolytic function. In Xenopus embryos, PACSIN2 is ubiquitously expressed, suggesting that PACSIN2 may control other proteins during development. To investigate this possibility, we studied PACSIN2 function during Xenopus gastrulation and in XTC cells. Our results show that PACSIN2 is localized to the plasma membrane via its coiled-coil domain. We also show that increased levels of PACSIN2 in embryos inhibit gastrulation, fibronectin (FN) fibrillogenesis and the ability of ectodermal cells to spread on a FN substrate. These effects require PACSIN2 coiled-coil domain and are not due to a reduction of FN or integrin expression and/or trafficking. The expression of a Mitochondria Anchored PACSIN2 (PACSIN2-MA) sequesters wild type PACSIN2 to mitochondria, and blocks gastrulation without interfering with cell spreading or FN fibrillogenesis but perturbs both epiboly and convergence/extension. In XTC cells, the over-expression of PACSIN2 but not PACSIN2-MA prevents the localization of integrin beta1 to focal adhesions (FA) and filamin to stress fiber. PACSIN2-MA prevents filamin localization to membrane ruffles but not to stress fiber. We propose that PACSIN2 may regulate gastrulation by controlling the population of activated alpha5beta1 integrin and cytoskeleton strength during cell movement. PMID:18495106

  7. The influence of tobacco smoking on adhesion molecule profiles

    PubMed Central

    Scott, DA; Palmer, RM

    2003-01-01

    Sequential interactions between several adhesion molecules and their ligands regulate lymphocyte circulation and leukocyte recruitment to inflammatory foci. Adhesion molecules are, therefore, central and critical components of the immune and inflammatory system. We review the evidence that tobacco smoking dysregulates specific components of the adhesion cascade, which may be a common factor in several smoking-induced diseases. Smoking causes inappropriate leukocyte activation, leukocyte-endothelial adhesion, and neutrophil entrapment in the microvasculature, which may help initiate local tissue destruction. Appropriate inflammatory reactions may thus be compromised. In addition to smoke-induced alterations to membrane bound endothelial and leukocyte adhesion molecule expression, which may help explain the above phenomena, smoking has a profound influence on circulating adhesion molecule profiles, most notably sICAM-1 and specific sCD44 variants. Elevated concentrations of soluble adhesion molecules may simply reflect ongoing inflammatory processes. However, increasing evidence suggests that specific soluble adhesion molecules are immunomodulatory, and that alterations to soluble adhesion molecule profiles may represent a significant risk factor for several diverse diseases. This evidence is discussed herein.

  8. The influence of tobacco smoking on adhesion molecule profiles

    PubMed Central

    Scott, DA; Palmer, RM

    2003-01-01

    Sequential interactions between several adhesion molecules and their ligands regulate lymphocyte circulation and leukocyte recruitment to inflammatory foci. Adhesion molecules are, therefore, central and critical components of the immune and inflammatory system. We review the evidence that tobacco smoking dysregulates specific components of the adhesion cascade, which may be a common factor in several smoking-induced diseases. Smoking causes inappropriate leukocyte activation, leukocyte-endothelial adhesion, and neutrophil entrapment in the microvasculature, which may help initiate local tissue destruction. Appropriate inflammatory reactions may thus be compromised. In addition to smoke-induced alterations to membrane bound endothelial and leukocyte adhesion molecule expression, which may help explain the above phenomena, smoking has a profound influence on circulating adhesion molecule profiles, most notably sICAM-1 and specific sCD44 variants. Elevated concentrations of soluble adhesion molecules may simply reflect ongoing inflammatory processes. However, increasing evidence suggests that specific soluble adhesion molecules are immunomodulatory, and that alterations to soluble adhesion molecule profiles may represent a significant risk factor for several diverse diseases. This evidence is discussed herein. PMID:19570245

  9. NGF-induced TrkA/CD44 association is involved in tumor aggressiveness and resistance to lestaurtinib

    PubMed Central

    Corbet, Cyril; Génot, Elisabeth; Adriaenssens, Eric; Chassat, Thierry; Bertucci, François; Daubon, Thomas; Magné, Nicolas

    2015-01-01

    There is accumulating evidence that TrkA and its ligand Nerve Growth Factor (NGF) are involved in cancer development. Staurosporine derivatives such as K252a and lestaurtinib have been developed to block TrkA kinase signaling, but no clinical trial has fully demonstrated their therapeutic efficacy. Therapeutic failures are likely due to the existence of intrinsic signaling pathways in cancer cells that impede or bypass the effects of TrkA tyrosine kinase inhibitors. To verify this hypothesis, we combined different approaches including mass spectrometry proteomics, co-immunoprecipitation and proximity ligation assays. We found that NGF treatment induced CD44 binding to TrkA at the plasma membrane and subsequent activation of the p115RhoGEF/RhoA/ROCK1 pathway to stimulate breast cancer cell invasion. The NGF-induced CD44 signaling was independent of TrkA kinase activity. Moreover, both TrkA tyrosine kinase inhibition with lestaurtinib and CD44 silencing with siRNA inhibited cell growth in vitro as well as tumor development in mouse xenograft model; combined treatment significantly enhanced the antineoplastic effects of either treatment alone. Altogether, our results demonstrate that NGF-induced tyrosine kinase independent TrkA signaling through CD44 was sufficient to maintain tumor aggressiveness. Our findings provide an alternative mechanism of cancer resistance to lestaurtinib and indicate that dual inhibition of CD44 and TrkA tyrosine kinase activity may represent a novel therapeutic strategy. PMID:25840418

  10. Surgically resected human tumors reveal the biological significance of the gastric cancer stem cell markers CD44 and CD26

    PubMed Central

    NISHIKAWA, SHIMPEI; KONNO, MASAMITSU; HAMABE, ATSUSHI; HASEGAWA, SHINICHIRO; KANO, YOSHIHIRO; FUKUSUMI, TAKAHITO; SATOH, TAROH; TAKIGUCHI, SHUJI; MORI, MASAKI; DOKI, YUICHIRO; ISHII, HIDESHI

    2015-01-01

    Cancer tissue is maintained by relatively small populations of cancer stem cells (CSCs), which are involved in chemotherapy resistance, recurrence and metastasis. As tumor tissues are comprised of various cells, studies of human clinical samples are important for the characterization of CSCs. In the present study, an expression profiling study was performed in which an anti-cell surface marker antibody-based array platform, a flow cytometry-based cell separation technique and a tumorigenicity analysis in immunodeficient animals were utilized. These approaches revealed that the markers cluster of differentiation (CD)44 and CD26 facilitated the fractionation of surgically resected human gastric cancer (GC) cells into the following subset populations with distinct tumorigenic potentials: Highly tumorigenic CD26+CD44+ cells (6/6 mice formed tumors), moderately tumorigenic CD26+CD44− cells (5/6 mice formed tumors), and weakly or non-tumorigenic CD26−CD44− cells (2/6 mice formed tumors). Furthermore, exposure to 5-fluorouracil significantly increased the proportion of CD26+ cells in vitro. The present study demonstrated that the combined expression of CD26 and CD44 presents a potential marker of human GC stem cells. PMID:26137071

  11. Physiological Contribution of CD44 as a Ligand for E-Selectin during Inflammatory T-Cell Recruitment

    PubMed Central

    Nácher, Maria; Blázquez, Ana Belén; Shao, Bojing; Matesanz, Adela; Prophete, Colette; Berin, M. Cecilia; Frenette, Paul S.; Hidalgo, Andrés

    2011-01-01

    Endothelial selectins guide the migration of inflammatory T cells to extralymphoid tissues. Whereas P-selectin glycoprotein ligand-1 (PSGL-1) functions as the exclusive ligand for P-selectin, it acts in coordination with additional glycoproteins to mediate E-selectin binding. CD44 can act as one such ligand in neutrophils, but its contribution in inflammatory T lymphocytes remains unexplored. We have used real-time in vivo imaging of the cremasteric and dermal microcirculations to explore the dynamics of leukocyte recruitment, as well as the physiological contribution of CD44 in a model of Th1-driven inflammation. CD4+ T-cell rolling frequency and kinetics, as well as arrest, were dependent on endothelial selectins and were markedly altered under inflammatory conditions. CD44 extracted from Th1 cells bound to soluble E-selectin in vitro and cooperated with PSGL-1 by controlling rolling velocities and promoting firm arrest. Using several competitive recruitment assays in a delayed-type hypersensitivity model, we show that the combined absence of CD44 and PSGL-1 impairs inflammatory T-cell recruitment beyond that of PSGL-1 alone. Differential expression of leukocyte fucosyltransferases in these cells may account for the differential use of E-selectin ligands relative to neutrophils. Our results identify additional mechanisms by which CD44 modulates the inflammatory response. PMID:21457936

  12. Expression of the matrix receptor CD44v5 on chondrocytes changes with osteoarthritis: an experimental investigation in the rabbit

    PubMed Central

    Tibesku, C O; Szuwart, T; Ocken, S A; Skwara, A; Fuchs, S

    2006-01-01

    Objective To evaluate the expression of CD44v5 on chondrocytes of hyaline cartilage during the course of osteoarthritis (OA). Methods In 12 white New Zealand rabbits the anterior cruciate ligament (ACL) was resected to create an anterior instability of the knee. In 12 control rabbits only a sham operation without resection of the ACL was done. Four animals of each group were killed at 3, 6, and 12 weeks. The loadbearing area was evaluated histologically according to Mankin and by immunostaining for CD44v5. Results In the trial group, histological grades of OA showed a positive linear correlation with the time after surgery. Immunostaining showed an increased expression of CD44v5 in the control group after 3 and 6 weeks, which dropped to normal after 12 weeks. There was no difference between control and trial groups after 3 and 6 weeks, but a difference was seen after 12 weeks. A significant positive correlation between CD44v5 expression and the histological grade of OA was found (r = 0.314). Conclusions An in vivo increase of expression of the hyaluronan receptor CD44v5 occurs during the course of OA. Further studies are needed to evaluate whether this pattern applies to man and whether new treatment approaches might evolve from this knowledge. PMID:16344493

  13. α6 Integrin and CD44 Enrich for a Primary Keratinocyte Population That Displays Resistance to UV-Induced Apoptosis

    PubMed Central

    Wray, Helen; Mackenzie, Ian C.; Storey, Alan; Navsaria, Harshad

    2012-01-01

    Epidermal human keratinocytes are exposed to a wide range of environmental genotoxic insults, including the UV component of solar radiation. Epidermal homeostasis in response to cellular or tissue damage is maintained by a population of keratinocyte stem cells (KSC) that reside in the basal layer of the epithelium. Using cell sorting based on cell-surface markers, we have identified a novel α6 integrinhigh+/CD44+ sub-population of basal keratinocytes. These α6 integrinhigh+/CD44+ keratinocytes have both high proliferative potential, form colonies in culture that have characteristics of holoclones and have a unique pattern of resistance to apoptosis induced by UVB radiation or by agents that induce single- or double strand DNA breaks. Resistance to UVB induced apoptosis in the α6 integrinhigh+/CD44+ cells involved increased expression of TAp63 and was overcome by PI-3 kinase inhibition. In marked contrast, the α6 integrinhigh+/CD44+ cells were sensitive to apoptosis induced by the cross-linking agent cisplatin, and imatinib inhibition of c-Abl blocked the ability of cisplatin to kill α6 integrinhigh+/CD44+ cells. Our findings reveal a population of basal keratinocytes with long-term proliferative properties that display specific patterns of apoptotic resistance that is dependent upon the genotoxic stimulus, and provide insights into how these cells can be targeted with chemotherapeutic agents. PMID:23071680

  14. Synovial fluid pretreatment with hyaluronidase facilitates isolation of CD44+ extracellular vesicles.

    PubMed

    Boere, Janneke; van de Lest, Chris H A; Libregts, Sten F W M; Arkesteijn, Ger J A; Geerts, Willie J C; Nolte-'t Hoen, Esther N M; Malda, Jos; van Weeren, P René; Wauben, Marca H M

    2016-01-01

    Extracellular vesicles (EVs) in synovial fluid (SF) are gaining increased recognition as important factors in joint homeostasis, joint regeneration, and as biomarkers of joint disease. A limited number of studies have investigated EVs in SF samples of patients with joint disease, but knowledge on the role of EVs in healthy joints is lacking. In addition, no standardized protocol is available for isolation of EVs from SF. Based on the high viscosity of SF caused by high concentrations of hyaluronic acid (HA) - a prominent extracellular matrix component - it was hypothesized that EV recovery could be optimized by pretreatment with hyaluronidase (HYase). Therefore, the efficiency of EV isolation from healthy equine SF samples was tested by performing sequential ultracentrifugation steps (10,000g, 100,000g and 200,000g) in the presence or absence of HYase. Quantitative EV analysis using high-resolution flow cytometry showed an efficient recovery of EVs after 100,000g ultracentrifugation, with an increased yield of CD44+ EVs when SF samples were pretreated with HYase. Morphological analysis of SF-derived EVs with cryo-transmission-electron microscopy did not indicate damage by high-speed ultracentrifugation and revealed that most EVs are spherical with a diameter of 20-200 nm. Further protein characterization by Western blotting revealed that healthy SF-derived EVs contain CD9, Annexin-1, and CD90/Thy1.1. Taken together, these data suggest that EV isolation protocols for body fluids that contain relatively high amounts of HA, such as SF, could benefit from treatment of the fluid with HYase prior to ultracentrifugation. This method facilitates recovery and detection of CD44+ EVs within the HA-rich extracellular matrix. Furthermore, based on the findings presented here, it is recommended to sediment SF-derived EVs with at least 100,000g for optimal EV recovery. PMID:27511891

  15. Synovial fluid pretreatment with hyaluronidase facilitates isolation of CD44+ extracellular vesicles

    PubMed Central

    Boere, Janneke; van de Lest, Chris H. A.; Libregts, Sten F. W. M.; Arkesteijn, Ger J. A.; Geerts, Willie J. C.; Nolte-'t Hoen, Esther N. M.; Malda, Jos; van Weeren, P. René; Wauben, Marca H. M.

    2016-01-01

    Extracellular vesicles (EVs) in synovial fluid (SF) are gaining increased recognition as important factors in joint homeostasis, joint regeneration, and as biomarkers of joint disease. A limited number of studies have investigated EVs in SF samples of patients with joint disease, but knowledge on the role of EVs in healthy joints is lacking. In addition, no standardized protocol is available for isolation of EVs from SF. Based on the high viscosity of SF caused by high concentrations of hyaluronic acid (HA) – a prominent extracellular matrix component – it was hypothesized that EV recovery could be optimized by pretreatment with hyaluronidase (HYase). Therefore, the efficiency of EV isolation from healthy equine SF samples was tested by performing sequential ultracentrifugation steps (10,000g, 100,000g and 200,000g) in the presence or absence of HYase. Quantitative EV analysis using high-resolution flow cytometry showed an efficient recovery of EVs after 100,000g ultracentrifugation, with an increased yield of CD44+ EVs when SF samples were pretreated with HYase. Morphological analysis of SF-derived EVs with cryo-transmission-electron microscopy did not indicate damage by high-speed ultracentrifugation and revealed that most EVs are spherical with a diameter of 20–200 nm. Further protein characterization by Western blotting revealed that healthy SF-derived EVs contain CD9, Annexin-1, and CD90/Thy1.1. Taken together, these data suggest that EV isolation protocols for body fluids that contain relatively high amounts of HA, such as SF, could benefit from treatment of the fluid with HYase prior to ultracentrifugation. This method facilitates recovery and detection of CD44+ EVs within the HA-rich extracellular matrix. Furthermore, based on the findings presented here, it is recommended to sediment SF-derived EVs with at least 100,000g for optimal EV recovery. PMID:27511891

  16. MDR1 siRNA loaded hyaluronic acid-based CD44 targeted nanoparticle systems circumvent paclitaxel resistance in ovarian cancer

    NASA Astrophysics Data System (ADS)

    Yang, Xiaoqian; Lyer, Arun K.; Singh, Amit; Choy, Edwin; Hornicek, Francis J.; Amiji, Mansoor M.; Duan, Zhenfeng

    2015-02-01

    Development of multidrug resistance (MDR) is an almost universal phenomenon in patients with ovarian cancer, and this severely limits the ultimate success of chemotherapy in the clinic. Overexpression of the MDR1 gene and corresponding P-glycoprotein (Pgp) is one of the best known MDR mechanisms. MDR1 siRNA based strategies were proposed to circumvent MDR, however, systemic, safe, and effective targeted delivery is still a major challenge. Cluster of differentiation 44 (CD44) targeted hyaluronic acid (HA) based nanoparticle has been shown to successfully deliver chemotherapy agents or siRNAs into tumor cells. The goal of this study is to evaluate the ability of HA-PEI/HA-PEG to deliver MDR1 siRNA and the efficacy of the combination of HA-PEI/HA-PEG/MDR1 siRNA with paclitaxel to suppress growth of ovarian cancer. We observed that HA-PEI/HA-PEG nanoparticles can efficiently deliver MDR1 siRNA into MDR ovarian cancer cells, resulting in down-regulation of MDR1 and Pgp expression. Administration of HA-PEI/HA-PEG/MDR1 siRNA nanoparticles followed by paclitaxel treatment induced a significant inhibitory effect on the tumor growth, decreased Pgp expression and increased apoptosis in MDR ovarian cancer mice model. Our findings suggest that CD44 targeted HA-PEI/HA-PEG/MDR1 siRNA nanoparticles can serve as a therapeutic tool with great potentials to circumvent MDR in ovarian cancer.

  17. Microtubules regulate focal adhesion dynamics through MAP4K4.

    PubMed

    Yue, Jiping; Xie, Min; Gou, Xuewen; Lee, Philbert; Schneider, Michael D; Wu, Xiaoyang

    2014-12-01

    Disassembly of focal adhesions (FAs) allows cell retraction and integrin detachment from the extracellular matrix, processes critical for cell movement. Growth of microtubules (MTs) can promote FA turnover by serving as tracks to deliver proteins essential for FA disassembly. The molecular nature of this FA "disassembly factor," however, remains elusive. By quantitative proteomics, we identified mitogen-activated protein kinase kinase kinase kinase 4 (MAP4K4) as an FA regulator that associates with MTs. Knockout of MAP4K4 stabilizes FAs and impairs cell migration. By exploring underlying mechanisms, we further show that MAP4K4 associates with ending binding 2 (EB2) and IQ motif and SEC7 domain-containing protein 1 (IQSEC1), a guanine nucleotide exchange factor specific for Arf6, whose activation promotes integrin internalization. Together, our findings provide critical insight into FA disassembly, suggesting that MTs can deliver MAP4K4 toward FAs through EB2, where MAP4K4 can, in turn, activate Arf6 via IQSEC1 and enhance FA dissolution. PMID:25490267

  18. Microtubules Regulate Focal Adhesion Dynamics through MAP4K4

    PubMed Central

    Yue, Jiping; Xie, Min; Gou, Xuewen; Lee, Philbert; Schneider, Michael D; Wu, Xiaoyang

    2014-01-01

    Disassembly of focal adhesions (FAs) allows cell retraction and integrin detachment from the ECM, processes critical for cell movement. Growth of MT (microtubule) can promote FA turnover by serving as tracks to deliver proteins essential for FA disassembly. The molecular nature of this FA “disassembly factor”, however, remains elusive. By quantitative proteomics, we identified MAP4K4 (mitogen-activated protein kinase kinase kinase kinase 4) as a FA regulator that associates with MTs. Conditional knockout (cKO) of MAP4K4 in skin stabilizes FAs and impairs epidermal migration. By exploring underlying mechanisms, we further show that MAP4K4 associates with EB2, a MT binding protein, and IQSEC1, a guanine nucleotide exchange factor (GEF) specific for Arf6, whose activation promotes integrin internalization. Together, our findings provide critical insights into FA disassembly, suggesting that MTs can deliver MAP4K4 toward FAs through EB2, where MAP4K4 can in turn activate Arf6 via IQSEC1 and enhance FA dissolution. PMID:25490267

  19. Model for how retrograde actin flow regulates adhesion traction stresses.

    PubMed

    Li, Ying; Bhimalapuram, Prabhakar; Dinner, Aaron R

    2010-05-19

    Cells from animals adhere to and exert mechanical forces on their surroundings. Cells must control these forces for many biological processes, and dysfunction can lead to pathologies. How the actions of molecules within a cell are coordinated to regulate the adhesive interaction with the extracellular matrix remains poorly understood. It has been observed that cytoplasmic proteins that link integrin cell-surface receptors with the actin cytoskeleton flow with varying rates from the leading edge toward the center of a cell. Here, we explore theoretically how measurable subcellular traction stresses depend on the local speed of retrograde actin flow. In the model, forces result from the stretching of molecular complexes in response to the drag from the flow; because these complexes break with extension-dependent kinetics, the flow results in a decrease in their number when sufficiently large. Competition between these two effects naturally gives rise to a clutch-like behavior and a nonmonotonic trend in the measured stresses, consistent with recent data for epithelial cells. We use this basic framework to evaluate slip and catch bond mechanisms for integrins; better fits of experimental data are obtained with a catch bond representation. Extension of the model to one comprising multiple molecular interfaces shifts the peak stress to higher speeds. Connections to other models and cell movement are discussed. PMID:21386439

  20. The Role of Lymphocyte to Monocyte Ratio, Microvessel Density and HiGH CD44 Tumor Cell Expression in Non Hodgkin Lymphomas.

    PubMed

    Jelicic, Jelena; Balint, Milena Todorovic; Jovanovic, Maja Perunicic; Boricic, Novica; Micev, Marjan; Stojsic, Jelena; Antic, Darko; Andjelic, Bosko; Bila, Jelena; Balint, Bela; Pavlovic, Sonja; Mihaljevic, Biljana

    2016-07-01

    Prognostic significance of immune microenvironment has been emphasized using the most advanced analysis, with consecutive attempts to reveal prognostic impact of this findings. The aim of this study was to compare and define prognostic significance of clinical parameters, microvessel density (MVD) in tumour tissue and expression of CD44s as adhesive molecule on tumour cells in diffuse large B cell lymphoma-DLBCL, primary central nervous system DLBCL-CNS DLBCL and follicular lymphoma-FL. A total of 202 histopathological samples (115 DLBCL/65 FL/22 CNS DLBCL) were evaluated. Overall response (complete/partial remission) was achieved in 81.3 % DLBCL patients, 81.8 % primary CNS DLBCL and 92.3 % FL. Absolute lymphocyte count-ALC/Absolute monocyte count-AMC >2.6 in DLBCL and ALC/AMC ≥ 4.7 in FL were associated with better event-free survival (EFS) and overall survival (OS) (p < 0.05). In DLBCL, MVD > 42 blood vessels/0.36 mm(2) correlated with primary resistant disease (p < 0.0001), poorer EFS and OS (p = 0.014). High CD44s expression in FL correlated with inferior EFS and OS (p < 0.01). In DLBCL, multivariate Cox regression analysis showed that ALC/AMC was independent parameter that affected OS (HR 3.27, 95 % CI 1.51-7.09, p = 0.003) along with the NCCN-IPI (HR 1.39, 95 % CI 1.08-1.79, p = 0.01). Furthermore, in FL, ALC/AMC mostly influenced OS (HR 5.21, 95 % CI 1.17-23.21, p = 0.03), followed with the FLIPI (HR 3.98, 95 % CI 1.06-14.95, p = 0.041). In DLBCL and FL, ALC/AMC is simple and robust tool that is, with current prognostic scores, able to define long-term survival and identify patients with inferior outcome. The introduction of immunochemotherapy might altered the prognostic significance of microenvionmental biomarkers (MVD and CD44s). PMID:26750138

  1. Nomogram Incorporating CD44v6 and Clinicopathological Factors to Predict Lymph Node Metastasis for Early Gastric Cancer

    PubMed Central

    Eom, Bang Wool; Joo, Jungnam; Park, Boram; Jo, Min Jung; Choi, Seung Ho; Cho, Soo-Jeong; Ryu, Keun Won; Kim, Young-Woo; Kook, Myeong-Cherl

    2016-01-01

    Background Treatment strategy for early gastric cancer depends on the probability of lymph node metastasis. The aim of this study is to develop a nomogram predicting lymph node metastasis in early gastric cancer using clinicopathological factors and biomarkers. Methods A literature review was performed to identify biomarkers related to lymph node metastasis in gastric cancer. Seven markers were selected and immunohistochemistry was performed in 336 early gastric cancer tissues. Based on the multivariable analysis, a prediction model including clinicopatholgical factors and biomarkers was developed, and benefit of adding biomarkers was evaluated using the area under the receiver operating curve and net reclassification improvement. Functional study in gastric cancer cell line was performed to evaluate mechanism of biomarker. Results Of the seven biomarkers studied, α1 catenin and CD44v6 were significantly associated with lymph node metastasis. A conventional prediction model, including tumor size, histological type, lymphatic blood vessel invasion, and depth of invasion, was developed. Then, a new prediction model including both clinicopathological factors and CD44v6 was developed. Net reclassification improvement analysis revealed a significant improvement of predictive performance by the addition of CD44v6, and a similar result was shown in the internal validation using bootstrapping. Prediction nomograms were then constructed based on these models. In the functional study, CD44v6 was revealed to affect cell proliferation, migration and invasion. Conclusions Overexpression of CD44v6 was a significant predictor of lymph node metastasis in early gastric cancer. The prediction nomograms incorporating CD44v6 can be useful to determine treatment plans in patients with early gastric cancer. PMID:27482895

  2. Key Roles of Hyaluronan and Its CD44 Receptor in the Stemness and Survival of Cancer Stem Cells

    PubMed Central

    Chanmee, Theerawut; Ontong, Pawared; Kimata, Koji; Itano, Naoki

    2015-01-01

    Cancer stem cells (CSCs) represent a unique subpopulation of self-renewing oncogenic cells that drive cancer initiation and progression. CSCs often acquire multidrug and oxidative stress resistance and are thereby thought to be responsible for tumor recurrence following treatment and remission. Although the mechanisms responsible for CSC generation, maintenance, and expansion have become a major focus in cancer research, the molecular characteristics of CSCs remain poorly understood. The stemness and subsequent expansion of CSCs are believed to be highly influenced by changes in microenvironmental signals as well as genetic and epigenetic alterations. Hyaluronan (HA), a major component of the extracellular matrix, has recently been demonstrated to provide a favorable microenvironment for the self-renewal and maintenance of stem cells. HA directly and indirectly affects CSC self-renewal by influencing the behavior of both cancer and stromal cells. For instance, HA in the tumor microenvironment modulates the function of tumor-associated macrophages to support CSC self-renewal, and excessive HA production promotes the acquisition of CSC signatures through epithelial-to-mesenchymal transition. The importance of HA in mediating CSC self-renewal has been strengthened by the finding that interactions between HA and its receptor, CD44, propagate the stemness of CSCs. HA–CD44 interactions evoke a wide range of signals required for CSC self-renewal and maintenance. CD44 also plays a critical role in the preservation and multidrug resistance (MDR) of CSCs by transmitting survival and anti-apoptotic signals. Thus, a better understanding of the molecular mechanisms involved in HA and CD44 control of CSC stemness may help in the design of more effective therapies for cancer patients. In this review, we address the key roles of HA and CD44 in CSC self-renewal and maintenance. We also discuss the involvement of CD44 in the oxidative stress and MDR of CSCs. PMID:26322272

  3. Fibroblast invasive migration into fibronectin/fibrin gels requires a previously uncharacterized dermatan sulfate-CD44 proteoglycan.

    PubMed

    Clark, Richard A F; Lin, Fubao; Greiling, Doris; An, Jianqang; Couchman, John R

    2004-02-01

    After tissue injury, fibroblast migration from the peri-wound collagenous stroma into the fibrin-laden wound is critical for granulation tissue formation and subsequent healing. Recently we found that fibroblast transmigration from a collagen matrix into a fibrin matrix required the presence of fibronectin. Several integrins-alpha 4 beta 1, alpha 5 beta 1, and alpha v beta 3-with known fibronectin binding affinity were necessary for this invasive migration. Here we examined another family of cell surface receptors: the proteoglycans. We found that dermatan sulfate was required for fibroblast migration into a fibronectin/fibrin gel. This conclusion was based on beta-xyloside inhibition of glycanation and specific glycosaminoglycan degradation. CD44, a cell surface receptor known to bind hyaluronan, not infrequently exists as a proteoglycan, decorated with various glycosaminoglycan chains including heparan sulfate and chondroitin sulfate, and as such can bind fibronectin. We found that CD44H, the non-spliced isoform of CD44, was necessary for fibroblast invasion into fibronectin/fibrin gels. Resting fibroblasts expressed mostly nonglycanated CD44H core protein, which became glycanated with chondroitin sulfate and dermatan sulfate, but not heparan sulfate, after a 24 h incubation with platelet-derived growth factor, the stimulus used in the migration assay. These results demonstrate that dermatan sulfate-CD44H proteoglycan is essential for fibroblast migration into fibrin clots and that platelet-derived growth factor, the stimulus for migration, induces the production of chondroitin-sulfate- and dermatan-sulfate-glycanated CD44H. PMID:15009704

  4. Extracellular Processing of the Cartilage Proteoglycan Aggregate and Its Effect on CD44-mediated Internalization of Hyaluronan*

    PubMed Central

    Danielson, Ben T.; Knudson, Cheryl B.; Knudson, Warren

    2015-01-01

    In many cells hyaluronan receptor CD44 mediates the endocytosis of hyaluronan and its delivery to endosomes/lysosomes. The regulation of this process remains largely unknown. In most extracellular matrices hyaluronan is not present as a free polysaccharide but often is found in complex with other small proteins and macromolecules such as proteoglycans. This is especially true in cartilage, where hyaluronan assembles into an aggregate structure with the large proteoglycan termed aggrecan. In this study when purified aggrecan was added to FITC-conjugated hyaluronan, no internalization of hyaluronan was detected. This suggested that the overall size of the aggregate prevented hyaluronan endocytosis and furthermore that proteolysis of the aggrecan was a required prerequisite for local, cell-based turnover of hyaluronan. To test this hypothesis, limited C-terminal digestion of aggrecan was performed to determine whether a size range of aggrecan exists that permits hyaluronan endocytosis. Our data demonstrate that only limited degradation of the aggrecan monomer was required to allow for hyaluronan internalization. When hyaluronan was combined with partially degraded, dansyl chloride-labeled aggrecan, blue fluorescent aggrecan was also visualized within intracellular vesicles. It was also determined that sonicated hyaluronan of smaller molecular size was internalized more readily than high molecular mass hyaluronan. However, the addition of intact aggrecan to hyaluronan chains sonicated for 5 and 10 s reblocked their endocytosis, whereas aggregates containing 15-s sonicated hyaluronan were internalized. These data suggest that hyaluronan endocytosis is regulated in large part by the extracellular proteolytic processing of hyaluronan-bound proteoglycan. PMID:25733665

  5. Poldip2 controls vascular smooth muscle cell migration by regulating focal adhesion turnover and force polarization

    PubMed Central

    Datla, Srinivasa Raju; McGrail, Daniel J.; Vukelic, Sasa; Huff, Lauren P.; Lyle, Alicia N.; Pounkova, Lily; Lee, Minyoung; Seidel-Rogol, Bonnie; Khalil, Mazen K.; Hilenski, Lula L.; Terada, Lance S.; Dawson, Michelle R.; Lassègue, Bernard

    2014-01-01

    Polymerase-δ-interacting protein 2 (Poldip2) interacts with NADPH oxidase 4 (Nox4) and regulates migration; however, the precise underlying mechanisms are unclear. Here, we investigated the role of Poldip2 in focal adhesion turnover, as well as traction force generation and polarization. Poldip2 overexpression (AdPoldip2) in vascular smooth muscle cells (VSMCs) impairs PDGF-induced migration and induces a characteristic phenotype of long cytoplasmic extensions. AdPoldip2 also prevents the decrease in spreading and increased aspect ratio observed in response to PDGF and slightly impairs cell contraction. Moreover, AdPoldip2 blocks focal adhesion dissolution and sustains H2O2 levels in focal adhesions, whereas Poldip2 knockdown (siPoldip2) significantly decreases the number of focal adhesions. RhoA activity is unchanged when focal adhesion dissolution is stimulated in control cells but increases in AdPoldip2-treated cells. Inhibition of RhoA blocks Poldip2-mediated attenuation of focal adhesion dissolution, and overexpression of RhoA or focal adhesion kinase (FAK) reverses the loss of focal adhesions induced by siPoldip2, indicating that RhoA and FAK mediate the effect of Poldip2 on focal adhesions. Nox4 silencing prevents focal adhesion stabilization by AdPoldip2 and induces a phenotype similar to siPoldip2, suggesting a role for Nox4 in Poldip2-induced focal adhesion stability. As a consequence of impaired focal adhesion turnover, PDGF-treated AdPoldip2 cells are unable to reduce and polarize traction forces, a necessary first step in migration. These results implicate Poldip2 in VSMC migration via regulation of focal adhesion turnover and traction force generation in a Nox4/RhoA/FAK-dependent manner. PMID:25063792

  6. Poldip2 controls vascular smooth muscle cell migration by regulating focal adhesion turnover and force polarization.

    PubMed

    Datla, Srinivasa Raju; McGrail, Daniel J; Vukelic, Sasa; Huff, Lauren P; Lyle, Alicia N; Pounkova, Lily; Lee, Minyoung; Seidel-Rogol, Bonnie; Khalil, Mazen K; Hilenski, Lula L; Terada, Lance S; Dawson, Michelle R; Lassègue, Bernard; Griendling, Kathy K

    2014-10-01

    Polymerase-δ-interacting protein 2 (Poldip2) interacts with NADPH oxidase 4 (Nox4) and regulates migration; however, the precise underlying mechanisms are unclear. Here, we investigated the role of Poldip2 in focal adhesion turnover, as well as traction force generation and polarization. Poldip2 overexpression (AdPoldip2) in vascular smooth muscle cells (VSMCs) impairs PDGF-induced migration and induces a characteristic phenotype of long cytoplasmic extensions. AdPoldip2 also prevents the decrease in spreading and increased aspect ratio observed in response to PDGF and slightly impairs cell contraction. Moreover, AdPoldip2 blocks focal adhesion dissolution and sustains H2O2 levels in focal adhesions, whereas Poldip2 knockdown (siPoldip2) significantly decreases the number of focal adhesions. RhoA activity is unchanged when focal adhesion dissolution is stimulated in control cells but increases in AdPoldip2-treated cells. Inhibition of RhoA blocks Poldip2-mediated attenuation of focal adhesion dissolution, and overexpression of RhoA or focal adhesion kinase (FAK) reverses the loss of focal adhesions induced by siPoldip2, indicating that RhoA and FAK mediate the effect of Poldip2 on focal adhesions. Nox4 silencing prevents focal adhesion stabilization by AdPoldip2 and induces a phenotype similar to siPoldip2, suggesting a role for Nox4 in Poldip2-induced focal adhesion stability. As a consequence of impaired focal adhesion turnover, PDGF-treated AdPoldip2 cells are unable to reduce and polarize traction forces, a necessary first step in migration. These results implicate Poldip2 in VSMC migration via regulation of focal adhesion turnover and traction force generation in a Nox4/RhoA/FAK-dependent manner. PMID:25063792

  7. LIN28B suppresses microRNA let-7b expression to promote CD44+/LIN28B+ human pancreatic cancer stem cell proliferation and invasion

    PubMed Central

    Shao, Yebo; Zhang, Lei; Cui, Lei; Lou, Wenhui; Wang, Dansong; Lu, Weiqi; Jin, Dayong; Liu, Te

    2015-01-01

    Although the highly proliferative, migratory, and multi-drug resistant phenotype of human pancreatic cancer stem cells (PCSCs) is well characterized, knowledge of their biological mechanisms is limited. We used CD44 and LIN28B as markers to screen, isolate, and enrich CSCs from human primary pancreatic cancer. Using flow cytometry, we identified a human primary pancreatic cancer cell (PCC) subpopulation expressing high levels of both CD44 and LIN28B. CD44+/LIN28B+ PCSCs expressed high levels of stemness marker genes and possessed higher migratory and invasive ability than CD44-/LIN28B- PCCs. CD44+/LIN28B+ PCSCs were more resistant to growth inhibition induced by the chemotherapeutic drugs cisplatin and gemcitabine hydrochloride, and readily established tumors in vivo in a relatively short time. Moreover, microarray analysis revealed significant differences between the cDNA expression patterns of CD44+/LIN28B+ PCSCs and CD44-/LIN28B- PCCs. Following siRNA interference of endogenous LIN28B gene expression in CD44+/LIN28B+ PCSCs, not only was their proliferation decreased, there was also cell cycle arrest due to suppression of cyclin D1 expression following the stimulation of miRNA let-7b expression. In conclusion, CD44+/LIN28B+ cells, which possess CSC characteristics, can be reliably sorted from human primary PCCs and represent a valuable model for studying cancer cell physiology and multi-drug resistance. PMID:26609473

  8. Kupffer cells and activation of endothelial TLR4 coordinate neutrophil adhesion within liver sinusoids during endotoxemia.

    PubMed

    McDonald, Braedon; Jenne, Craig N; Zhuo, Lisheng; Kimata, Koji; Kubes, Paul

    2013-12-01

    A key pathological feature of the systemic inflammatory response of sepsis/endotoxemia is the accumulation of neutrophils within the microvasculature of organs such as the liver, where they cause tissue damage and vascular dysfunction. There is emerging evidence that the vascular endothelium is critical to the orchestration of inflammatory responses to blood-borne microbes and microbial products in sepsis/endotoxemia. In this study, we aimed to understand the role of endothelium, and specifically endothelial TLR4 activation, in the regulation of neutrophil recruitment to the liver during endotoxemia. Intravital microscopy of bone marrow chimeric mice revealed that TLR4 expression by non-bone marrow-derived cells was required for neutrophil recruitment to the liver during endotoxemia. Furthermore, LPS-induced neutrophil adhesion in liver sinusoids was equivalent between wild-type mice and transgenic mice that express TLR4 only on endothelium (tlr4(-/-)Tie2(tlr4)), revealing that activation of endothelial TLR4 alone was sufficient to initiate neutrophil adhesion. Neutrophil arrest within sinusoids of endotoxemic mice requires adhesive interactions between neutrophil CD44 and endothelial hyaluronan. Intravital immunofluorescence imaging demonstrated that stimulation of endothelial TLR4 alone was sufficient to induce the deposition of serum-derived hyaluronan-associated protein (SHAP) within sinusoids, which was required for CD44/hyaluronan-dependent neutrophil adhesion. In addition to endothelial TLR4 activation, Kupffer cells contribute to neutrophil recruitment via a distinct CD44/HA/SHAP-independent mechanism. This study sheds new light on the control of innate immune activation within the liver vasculature during endotoxemia, revealing a key role for endothelial cells as sentinels in the detection of intravascular infections and coordination of neutrophil recruitment to the liver. PMID:24113769

  9. Determining graphene adhesion via substrate-regulated morphology of graphene

    NASA Astrophysics Data System (ADS)

    Zhang, Zhao; Li, Teng

    2011-10-01

    Understanding the adhesion between graphene and other materials is crucial for achieving more reliable graphene-based applications in electronic devices and nanocomposites. The ultra-thin profile of graphene, however, poses a significant challenge to direct measurement of its adhesion property using conventional approaches. We show that there is a strong correlation between the morphology of graphene on a compliant substrate with patterned surface and the graphene-substrate adhesion. We establish an analytic model to quantitatively determine such a strong correlation. Results show that, depending on the graphene-substrate adhesion, number of graphene layers, and substrate stiffness, graphene exhibits two distinct types of morphology: (I) graphene remains bonded to the substrate and corrugates to an amplitude up to that of the substrate surface patterns; (II) graphene debonds from the substrate and remains flat on top of the substrate surface patterns. The sharp transition between these two types of graphene morphology occurs at a critical adhesion between the graphene and the compliant substrate material. These results potentially open up a feasible pathway to measuring the adhesion property of graphene.

  10. TRPM7 Regulates Cell Adhesion by Controlling the Calcium-dependent Protease Calpain*S

    PubMed Central

    Su, Li-Ting; Agapito, Maria A.; Li, Mingjiang; Simonson, William T. N.; Huttenlocher, Anna; Habas, Raymond; Yue, Lixia; Runnels, Loren W.

    2011-01-01

    m-Calpain is a protease implicated in the control of cell adhesion through focal adhesion disassembly. The mechanism by which the enzyme is spatially and temporally controlled is not well understood, particularly because the dependence of calpain on calcium exceeds the submicromolar concentrations normally observed in cells. Here we show that the channel kinase TRPM7 localizes to peripheral adhesion complexes with m-calpain, where it regulates cell adhesion by controlling the activity of the protease. Our research revealed that overexpression of TRPM7 in cells caused cell rounding with a concomitant loss of cell adhesion that is dependent upon the channel of the protein but not its kinase activities. Knockdown of m-calpain blocked TRPM7-induced cell rounding and cell detachment. Silencing of TRPM7 by RNA interference, however, strengthened cell adhesion and increased the number of peripheral adhesion complexes in the cells. Together, our results suggest that the ion channel TRPM7 regulates cell adhesion through m-calpain by mediating the local influx of calcium into peripheral adhesion complexes. PMID:16436382

  11. Robust fluorescence sensing platform for detection of CD44 cells based on graphene oxide/gold nanoparticles.

    PubMed

    Jeong, Ha Young; Baek, Seung Hun; Chang, Sung-Jin; Cheon, Seon Ah; Park, Tae Jung

    2015-11-01

    Gold-coated graphene oxide hybrid material (GO/AuNPs) has exceptional physical and chemical properties like π-π stacking interaction and plays a role in quencher of fluorescence dye. Therefore, GO/AuNPs could enhance the signal-to-background ratio with fluorescence dye that was the point in this fluorescent biosensor. In this study, tetramethyl-6-carboxy-rhodamine (TAMRA)-labeled aptamers that specifically interact with the hyaluronic acid binding domain of CD44 were used as targets to investigate the applicability of the method. GO/AuNPs-TAMRA-aptamer complexes could detect CD44 target cancer cells within a concentration range of 1 × 10(1) to 1 × 10(7) CFU/mL. A linear relationship was observed between target cell concentration and relative fluorescence intensity. The more mounted up CD44 target cell concentrations, relative fluorescence intensity of GO/AuNPs-TAMRA-aptamer complexes was increased even more, which was superior to that of GO alone. Sensitivity of the detection system displayed a low detection limit of 1 × 10(1) CFU/mL. Additionally, this method is specific in that fluorescence is not much enhanced in CD44 negative cancer cell line. Thus, the fluorescence sensing based on GO/AuNPs could be developed to receptive and robust detection tool for various target molecules. PMID:26263218

  12. Regulation of brain tumor dispersal by NKCC1 through a novel role in focal adhesion regulation.

    PubMed

    Garzon-Muvdi, Tomas; Schiapparelli, Paula; ap Rhys, Colette; Guerrero-Cazares, Hugo; Smith, Christopher; Kim, Deok-Ho; Kone, Lyonell; Farber, Harrison; Lee, Danielle Y; An, Steven S; Levchenko, Andre; Quiñones-Hinojosa, Alfredo

    2012-01-01

    Glioblastoma (GB) is a highly invasive and lethal brain tumor due to its universal recurrence. Although it has been suggested that the electroneutral Na(+)-K(+)-Cl(-) cotransporter 1 (NKCC1) can play a role in glioma cell migration, the precise mechanism by which this ion transporter contributes to GB aggressiveness remains poorly understood. Here, we focused on the role of NKCC1 in the invasion of human primary glioma cells in vitro and in vivo. NKCC1 expression levels were significantly higher in GB and anaplastic astrocytoma tissues than in grade II glioma and normal cortex. Pharmacological inhibition and shRNA-mediated knockdown of NKCC1 expression led to decreased cell migration and invasion in vitro and in vivo. Surprisingly, knockdown of NKCC1 in glioma cells resulted in the formation of significantly larger focal adhesions and cell traction forces that were approximately 40% lower than control cells. Epidermal growth factor (EGF), which promotes migration of glioma cells, increased the phosphorylation of NKCC1 through a PI3K-dependant mechanism. This finding is potentially related to WNK kinases. Taken together, our findings suggest that NKCC1 modulates migration of glioma cells by two distinct mechanisms: (1) through the regulation of focal adhesion dynamics and cell contractility and (2) through regulation of cell volume through ion transport. Due to the ubiquitous expression of NKCC1 in mammalian tissues, its regulation by WNK kinases may serve as new therapeutic targets for GB aggressiveness and can be exploited by other highly invasive neoplasms. PMID:22570591

  13. Epithelial adhesion molecules and the regulation of intestinal homeostasis during neutrophil transepithelial migration.

    PubMed

    Sumagin, Ronen; Parkos, Charles A

    2015-01-01

    Epithelial adhesion molecules play essential roles in regulating cellular function and maintaining mucosal tissue homeostasis. Some form epithelial junctional complexes to provide structural support for epithelial monolayers and act as a selectively permeable barrier separating luminal contents from the surrounding tissue. Others serve as docking structures for invading viruses and bacteria, while also regulating the immune response. They can either obstruct or serve as footholds for the immune cells recruited to mucosal surfaces. Currently, it is well appreciated that adhesion molecules collectively serve as environmental cue sensors and trigger signaling events to regulate epithelial function through their association with the cell cytoskeleton and various intracellular adapter proteins. Immune cells, particularly neutrophils (PMN) during transepithelial migration (TEM), can modulate adhesion molecule expression, conformation, and distribution, significantly impacting epithelial function and tissue homeostasis. This review discusses the roles of key intestinal epithelial adhesion molecules in regulating PMN trafficking and outlines the potential consequences on epithelial function. PMID:25838976

  14. Epithelial adhesion molecules and the regulation of intestinal homeostasis during neutrophil transepithelial migration

    PubMed Central

    Sumagin, Ronen; Parkos, Charles A

    2014-01-01

    Epithelial adhesion molecules play essential roles in regulating cellular function and maintaining mucosal tissue homeostasis. Some form epithelial junctional complexes to provide structural support for epithelial monolayers and act as a selectively permeable barrier separating luminal contents from the surrounding tissue. Others serve as docking structures for invading viruses and bacteria, while also regulating the immune response. They can either obstruct or serve as footholds for the immune cells recruited to mucosal surfaces. Currently, it is well appreciated that adhesion molecules collectively serve as environmental cue sensors and trigger signaling events to regulate epithelial function through their association with the cell cytoskeleton and various intracellular adapter proteins. Immune cells, particularly neutrophils (PMN) during transepithelial migration (TEM), can modulate adhesion molecule expression, conformation, and distribution, significantly impacting epithelial function and tissue homeostasis. This review discusses the roles of key intestinal epithelial adhesion molecules in regulating PMN trafficking and outlines the potential consequences on epithelial function. PMID:25838976

  15. Maintenance of the stemness in CD44(+) HCT-15 and HCT-116 human colon cancer cells requires miR-203 suppression.

    PubMed

    Ju, Sy-Yeuan; Chiou, Shih-Hwa; Su, Yeu

    2014-01-01

    The purpose of this study was to isolate cancer stem cells (CSCs, also called tumor-initiating cells, TICs) from established human colorectal carcinoma (CRC) cell lines, characterize them extensively and dissect the mechanism for their stemness. Freshly isolated CD44(+) and CD44(-) cells from the HCT-15 human colon cancer cell line were subjected to various analyses. Interestingly, CD44(+) cells exhibited higher soft agar colony-forming ability and in vivo tumorigenicity than CD44(-) cells. In addition, the significant upregulation of the protein Snail and the downregulation of miR-203, a stemness inhibitor, in CD44(+) cells suggested that this population possessed higher invasion/metastasis and differentiation potential than CD44(-) cells. By manipulating the expression of CD44 in HCT-15 and HCT-116 cells, we found that the levels of several EMT activators and miR-203 were positively and negatively correlated with those of CD44, respectively. Further analyses revealed that miR-203 levels were repressed by Snail, which was shown to bind to specific E-box(es) present in the miR-203 promoter. In agreement, silencing miR-203 expression in wild-type HCT-116 human colon cancer cells also resulted in an increase of their stemness. Finally, we discovered that c-Src kinase activity was required for the downregulation of miR-203 in HCT-15 cells, which was stimulated by the interaction between hyaluronan (HA) and CD44. Taken together, CD44 is a critical molecule for modulating stemness in CSCs. More importantly, we show for the first time that the downregulation of miR-203 by HA/CD44 signaling is the main reason for stemness-maintenance in colon cancer cells. PMID:24145190

  16. Differential surface expression of CD18 and CD44 by neutrophils in bone marrow and spleen contributed to the neutrophilia in thalidomide-treated female B6C3F1 mice

    SciTech Connect

    Auttachoat, Wimolnut; Zheng Jianfeng; Chi, Rui P.; Meng, Andrew; Guo, Tai L. . E-mail: tlguo@vcu.edu

    2007-02-01

    Previously, we have reported that thalidomide (Thd) can enhance neutrophil function in female B6C3F1 mice. The present study was intended to evaluate the mechanisms underlying the enhanced neutrophil responses following Thd treatment intraperitoneally (100 mg/kg) for 14 or 28 days. Treatment with Thd increased the numbers of neutrophils in the spleen, peripheral blood, bone marrow, peritoneal cavity and lungs of female B6C3F1 mice when compared to the vehicle control mice. Thd treatment for 14 days increased the percentage and the number of neutrophils in the spleen in the first 8 h (peaking at 2 h) after the last Thd treatment, and it returned to the baseline after 24 h. However, Thd treatment for 28 days increased the percentage and number of neutrophils in the spleen even at the 24-h time point after the last Thd treatment. These neutrophils were demonstrated to be functional by the myeloperoxidase activity assay. Further studies have ruled out the possibility of an increased bone marrow granulopoiesis following Thd treatment. Flow cytometric analysis of the surface expression of adhesion molecules suggested that Thd treatment for either 14 or 28 days decreased the surface expression of either CD18 or CD44 by bone marrow neutrophils. On the other hand, the surface expression of both CD18 and CD44 by splenic neutrophils was increased following Thd treatment for 28 days but not for 14 days. No effect was produced for other cell surface molecules such as CD62L and CD11a. It was possible that decreased surface expressions of CD18 and CD44 facilitated neutrophils' release from the bone marrow; increased surface expressions of CD44 and CD18 by splenic neutrophils after 28 days of Thd treatment increased their ability to remain in the periphery. Taken together, Thd treatment increased neutrophils in female B6C3F1 mice, at least partially, through differentially modulating the surface expression of CD18 and CD44 by the neutrophils in the bone marrow and spleen00.

  17. Hyaluronic acid based self-assembling nanosystems for CD44 target mediated siRNA delivery to solid tumors

    PubMed Central

    Ganesh, Shanthi; Iyer, Arun K.; Morrissey, David V.; Amiji, Mansoor M.

    2013-01-01

    Anticancer therapeutics employing RNA interference mechanism holds promising potentials for sequence-specific silencing of target genes. However targeted delivery of siRNAs to tumor tissues and cells and more importantly, their intracellular release at sites of interest still remains a major challenge that needs to be addressed before this technique could become a clinically viable option. In the current study, we have engineered and screened a series of CD44 targeting hyaluronic acid (HA) based self-assembling nanosystems for targeted siRNA delivery. The HA polymer was functionalized with lipids of varying carbon chain lengths/nitrogen content, as well as polyamines for assessing siRNA encapsulation. From the screens, several HA-derivatives were identified that could stably encapsulate/complex siRNAs and form self-assembled nanosystems, as determined by gel retardation assays and dynamic light scattering. Many HA derivatives could transfect siRNAs into cancer cells overexpressing CD44 receptors. Interestingly, blocking the CD44 receptors on the cells using free excess soluble HA prior to incubation of cy3-labeled-siRNA loaded HA nano-assemblies resulted in >90% inhibition of the receptor mediated uptake, confirming target specificity. In addition, SSB/PLK1 siRNA encapsulated in HA-PEI/PEG nanosystems demonstrated dose dependent and target specific gene knockdown in both sensitive and resistant A549 lung cancer cells overexpressing CD44 receptors. More importantly, these siRNA encapsulated nanosystems demonstrated tumor selective uptake and target specific gene knock down in vivo in solid tumors as well as in metastatic tumors. The HA based nanosystems thus portend to be promising siRNA delivery vectors for systemic targeting of CD44 overexpressing cancers including tumor initiating (stem-) cells and metastatic lesions. PMID:23410679

  18. CD133 and CD44 are universally overexpressed in GIST and do not represent cancer stem cell markers

    PubMed Central

    Chen, Junwei; Guo, Tianhua; Zhang, Lei; Qin, Li-Xuan; Singer, Samuel; Maki, Robert G.; Taguchi, Takahiro; DeMatteo, Ronald; Besmer, Peter; Antonescu, Cristina R

    2012-01-01

    Although imatinib mesylate has been a major breakthrough in the treatment of advanced GIST, complete responses are rare and most patients eventually develop resistance to the drug. Thus the possibility of an imatinib-insensitive cell subpopulation within GIST tumors, harboring stem cell characteristics, may be responsible for the clinical failures. However, the existence of a cancer stem cell component in GIST has not been yet established. The present study was aimed to determine whether expression of commonly used stem cell markers in other malignancies, i.e. CD133 and CD44, might identify cells with characteristics of cancer stem/progenitor cells in human GIST. CD133 and CD44 expression in GIST explants was analyzed by flow cytometry, immunofluorescence, and gene expression. Their transcription levels were correlated with clinical and molecular factors in a large, well-annotated cohort of GIST patients. FACS sorted GIST cells based on CD133 and CD44 expression were isolated and used to assess phenotypic characteristics, ability to maintain their surface expression, sensitivity to imatinib, and expression signature. The enrichment in CD133/CD44 cells in the side population (SP) assay was also investigated. CD133 expression was consistently found in GIST. CD133− cells formed more colonies, were more invasive in a matrigel assay, and showed enrichment in the SP cells, compared to CD133+ cells. CD133 expression was also detected in the two imatinib-sensitive GIST cell lines, while was absent in the imatinib-resistant lines. Our results show that CD133 and CD44 are universally expressed in GIST, and may represent a lineage rather than a cancer stem cell marker. PMID:22076958

  19. Application of Collagen-Model Triple-Helical Peptide-Amphiphiles for CD44-Targeted Drug Delivery Systems

    PubMed Central

    Ndinguri, Margaret W.; Zheleznyak, Alexander; Lauer, Janelle L.; Anderson, Carolyn J.; Fields, Gregg B.

    2012-01-01

    Cancer treatment by chemotherapy is typically accompanied by deleterious side effects, attributed to the toxic action of chemotherapeutics on proliferating cells from nontumor tissues. The cell surface proteoglycan CD44 has been recognized as a cancer stem cell marker. The present study has examined CD44 targeting as a way to selectively deliver therapeutic agents encapsulated inside colloidal delivery systems. CD44/chondroitin sulfate proteoglycan binds to a triple-helical sequence derived from type IV collagen, α1(IV)1263–1277. We have assembled a peptide-amphiphile (PA) in which α1(IV)1263–1277 was sandwiched between 4 repeats of Gly-Pro-4-hydroxyproline and conjugated to palmitic acid. The PA was incorporated into liposomes composed of DSPG, DSPC, cholesterol, and DSPE-PEG-2000 (1 : 4 : 5 : 0.5). Doxorubicin-(DOX-)loaded liposomes with and without 10% α1(IV)1263–1277 PA were found to exhibit similar stability profiles. Incubation of DOX-loaded targeted liposomes with metastatic melanoma M14#5 and M15#11 cells and BJ fibroblasts resulted in IC50 values of 9.8, 9.3, and >100 μM, respectively. Nontargeted liposomes were considerably less efficacious for M14#5 cells. In the CD44+ B16F10 mouse melanoma model, CD44-targeted liposomes reduced the tumor size to 60% of that of the untreated control, whereas nontargeted liposomes were ineffective. These results suggest that PA targeted liposomes may represent a new class of nanotechnology-based drug delivery systems. PMID:23213537

  20. The Accumulation of Intracellular ITEGE and DIPEN Neoepitopes in Bovine Articular Chondrocytes Is Mediated by CD44 Internalization of Hyaluronan

    PubMed Central

    Flory, Jennifer J. Embry; Fosang, Amanda J.; Knudson, Warren

    2011-01-01

    Objective A dramatic loss of aggrecan proteoglycan from cartilage is associated with osteoarthritis. The fate of residual G1 domains of aggrecan is unknown, but inefficient turnover of these domains may impede subsequent repair and retention of newly synthesized aggrecan. Thus, the objective of this study was to determine whether ITEGE- and DIPEN-containing G1 domains, generated in situ, are internalized by articular chondrocytes, and whether these events are dependent on hyaluronan (HA) and its receptor, CD44. Methods ITEGE and DIPEN neoepitopes were detected by immunofluorescence staining of bovine articular cartilage chondrocytes treated with or without interleukin-1α (IL-1α). Additionally, purified ITEGE- or DIPEN-containing G1 domains were aggregated with HA and then added to articular chondrocytes, articular chondrocytes transfected with CD44Δ67, or COS-7 cells transfected with or without full-length CD44. Internalized epitopes were distinguished by their resistance to extensive trypsinization of the cell surface. Results Both ITEGE and DIPEN were visualized within the extracellular cell-associated matrix of chondrocytes as well as within intracellular vesicles. Following trypsinization, the intracellular accumulation of both epitopes was clearly visible. IL-1 treatment increased extracellular as well as intracellular ITEGE epitope accumulation. Once internalized, the ITEGE neoepitope became localized within the nucleus and displayed little colocalization with HA, DIPEN, or other G1 domain epitopes. The internalization of both ITEGE and DIPEN G1 domains was dependent on the presence of HA and CD44. Conclusion One important mechanism for the elimination of residual G1 domains following extracellular degradation of aggrecan is CD44-mediated co-internalization with HA. PMID:16447219

  1. Conformational and functional variants of CD44-targeted protein nanoparticles bio-produced in bacteria.

    PubMed

    Pesarrodona, Mireia; Fernández, Yolanda; Foradada, Laia; Sánchez-Chardi, Alejandro; Conchillo-Solé, Oscar; Unzueta, Ugutz; Xu, Zhikun; Roldán, Mónica; Villegas, Sandra; Ferrer-Miralles, Neus; Schwartz, Simó; Rinas, Ursula; Daura, Xavier; Abasolo, Ibane; Vázquez, Esther; Villaverde, Antonio

    2016-06-01

    Biofabrication is attracting interest as a means to produce nanostructured functional materials because of its operational versatility and full scalability. Materials based on proteins are especially appealing, as the structure and functionality of proteins can be adapted by genetic engineering. Furthermore, strategies and tools for protein production have been developed and refined steadily for more than 30 years. However, protein conformation and therefore activity might be sensitive to production conditions. Here, we have explored whether the downstream strategy influences the structure and biological activities, in vitro and in vivo, of a self-assembling, CD44-targeted protein-only nanoparticle produced in Escherichia coli. This has been performed through the comparative analysis of particles built from soluble protein species or protein versions obtained by in vitro protein extraction from inclusion bodies, through mild, non-denaturing procedures. These methods have been developed recently as a convenient alternative to the use of toxic chaotropic agents for protein resolubilization from protein aggregates. The results indicate that the resulting material shows substantial differences in its physicochemical properties and its biological performance at the systems level, and that its building blocks are sensitive to the particular protein source. PMID:27078873

  2. Nanotopographical modification: a regulator of cellular function through focal adhesions

    PubMed Central

    Biggs, Manus Jonathan Paul; Richards, R. Geoff; Dalby, Matthew J.

    2010-01-01

    As materials technology and the field of biomedical engineering advances, the role of cellular mechanisms, in particular adhesive interactions with implantable devices, becomes more relevant in both research and clinical practice. A key tenet of medical device design has evolved from the exquisite ability of biological systems to respond to topographical features or chemical stimuli, a process that has led to the development of next-generation biomaterials for a wide variety of clinical disorders. In vitro studies have identified nanoscale features as potent modulators of cellular behavior through the onset of focal adhesion formation. The focus of this review is on the recent developments concerning the role of nanoscale structures on integrin-mediated adhesion and cellular function with an emphasis on the generation of medical constructs with regenerative applications. PMID:20138244

  3. Cell adhesion in regulation of asymmetric stem cell division

    PubMed Central

    Yamashita, Yukiko M.

    2010-01-01

    Adult stem cells inevitably communicate with their cellular neighbors within the tissues they sustain. Indeed, such communication, particularly with components of the stem cell niche, is essential for many aspects of stem cell behavior, including the maintenance of stem cell identity and asymmetric cell division. Cell adhesion mediates this communication by placing stem cells in close proximity to the signaling source and by providing a polarity cue that orients stem cells. Here, I review the recent discovery that cell adhesion molecules govern the behavior of stem cells. PMID:20724132

  4. Local 3D matrix microenvironment regulates cell migration through spatiotemporal dynamics of contractility-dependent adhesions.

    PubMed

    Doyle, Andrew D; Carvajal, Nicole; Jin, Albert; Matsumoto, Kazue; Yamada, Kenneth M

    2015-01-01

    The physical properties of two-dimensional (2D) extracellular matrices (ECMs) modulate cell adhesion dynamics and motility, but little is known about the roles of local microenvironmental differences in three-dimensional (3D) ECMs. Here we generate 3D collagen gels of varying matrix microarchitectures to characterize their regulation of 3D adhesion dynamics and cell migration. ECMs containing bundled fibrils demonstrate enhanced local adhesion-scale stiffness and increased adhesion stability through balanced ECM/adhesion coupling, whereas highly pliable reticular matrices promote adhesion retraction. 3D adhesion dynamics are locally regulated by ECM rigidity together with integrin/ECM association and myosin II contractility. Unlike 2D migration, abrogating contractility stalls 3D migration regardless of ECM pore size. We find force is not required for clustering of activated integrins on 3D native collagen fibrils. We propose that efficient 3D migration requires local balancing of contractility with ECM stiffness to stabilize adhesions, which facilitates the detachment of activated integrins from ECM fibrils. PMID:26548801

  5. Local 3D matrix microenvironment regulates cell migration through spatiotemporal dynamics of contractility-dependent adhesions

    PubMed Central

    Doyle, Andrew D.; Carvajal, Nicole; Jin, Albert; Matsumoto, Kazue; Yamada, Kenneth M.

    2015-01-01

    The physical properties of two-dimensional (2D) extracellular matrices (ECMs) modulate cell adhesion dynamics and motility, but little is known about the roles of local microenvironmental differences in three-dimensional (3D) ECMs. Here we generate 3D collagen gels of varying matrix microarchitectures to characterize their regulation of 3D adhesion dynamics and cell migration. ECMs containing bundled fibrils demonstrate enhanced local adhesion-scale stiffness and increased adhesion stability through balanced ECM/adhesion coupling, whereas highly pliable reticular matrices promote adhesion retraction. 3D adhesion dynamics are locally regulated by ECM rigidity together with integrin/ECM association and myosin II contractility. Unlike 2D migration, abrogating contractility stalls 3D migration regardless of ECM pore size. We find force is not required for clustering of activated integrins on 3D native collagen fibrils. We propose that efficient 3D migration requires local balancing of contractility with ECM stiffness to stabilize adhesions, which facilitates the detachment of activated integrins from ECM fibrils. PMID:26548801

  6. Local 3D matrix microenvironment regulates cell migration through spatiotemporal dynamics of contractility-dependent adhesions

    NASA Astrophysics Data System (ADS)

    Doyle, Andrew D.; Carvajal, Nicole; Jin, Albert; Matsumoto, Kazue; Yamada, Kenneth M.

    2015-11-01

    The physical properties of two-dimensional (2D) extracellular matrices (ECMs) modulate cell adhesion dynamics and motility, but little is known about the roles of local microenvironmental differences in three-dimensional (3D) ECMs. Here we generate 3D collagen gels of varying matrix microarchitectures to characterize their regulation of 3D adhesion dynamics and cell migration. ECMs containing bundled fibrils demonstrate enhanced local adhesion-scale stiffness and increased adhesion stability through balanced ECM/adhesion coupling, whereas highly pliable reticular matrices promote adhesion retraction. 3D adhesion dynamics are locally regulated by ECM rigidity together with integrin/ECM association and myosin II contractility. Unlike 2D migration, abrogating contractility stalls 3D migration regardless of ECM pore size. We find force is not required for clustering of activated integrins on 3D native collagen fibrils. We propose that efficient 3D migration requires local balancing of contractility with ECM stiffness to stabilize adhesions, which facilitates the detachment of activated integrins from ECM fibrils.

  7. PI3K{gamma} activation by CXCL12 regulates tumor cell adhesion and invasion

    SciTech Connect

    Monterrubio, Maria; Mellado, Mario; Carrera, Ana C.

    2009-10-16

    Tumor dissemination is a complex process, in which certain steps resemble those in leukocyte homing. Specific chemokine/chemokine receptor pairs have important roles in both processes. CXCL12/CXCR4 is the most commonly expressed chemokine/chemokine receptor pair in human cancers, in which it regulates cell adhesion, extravasation, metastatic colonization, angiogenesis, and proliferation. All of these processes require activation of signaling pathways that include G proteins, phosphatidylinositol-3 kinase (PI3K), JAK kinases, Rho GTPases, and focal adhesion-associated proteins. We analyzed these pathways in a human melanoma cell line in response to CXCL12 stimulation, and found that PI3K{gamma} regulates tumor cell adhesion through mechanisms different from those involved in cell invasion. Our data indicate that, following CXCR4 activation after CXCL12 binding, the invasion and adhesion processes are regulated differently by distinct downstream events in these signaling cascades.

  8. Overexpression of CD44 in Neural Precursor Cells Improves Trans- Endothelial Migration and Facilitates Their Invasion of Perivascular Tissues In Vivo

    PubMed Central

    Deboux, Cyrille; Ladraa, Sophia; Cazaubon, Sylvie; Ghribi-Mallah, Siham; Weiss, Nicolas; Chaverot, Nathalie; Couraud, Pierre Olivier; Evercooren, Anne Baron-Van

    2013-01-01

    Neural precursor (NPC) based therapies are used to restore neurons or oligodendrocytes and/or provide neuroprotection in a large variety of neurological diseases. In multiple sclerosis models, intravenously (i.v) -delivered NPCs reduced clinical signs via immunomodulation. We demonstrated recently that NPCs were able to cross cerebral endothelial cells in vitro and that the multifunctional signalling molecule, CD44 involved in trans-endothelial migration of lymphocytes to sites of inflammation, plays a crucial role in extravasation of syngeneic NPCs. In view of the role of CD44 in NPCs trans-endothelial migration in vitro, we questioned presently the benefit of CD44 overexpression by NPCs in vitro and in vivo, in EAE mice. We show that overexpression of CD44 by NPCs enhanced over 2 folds their trans-endothelial migration in vitro, without impinging on the proliferation or differentiation potential of the transduced cells. Moreover, CD44 overexpression by NPCs improved significantly their elongation, spreading and number of filopodia over the extracellular matrix protein laminin in vitro. We then tested the effect of CD44 overexpression after i.v. delivery in the tail vein of EAE mice. CD44 overexpression was functional in vivo as it accelerated trans-endothelial migration and facilitated invasion of HA expressing perivascular sites. These in vitro and in vivo data suggest that CD44 may be crucial not only for NPC crossing the endothelial layer but also for facilitating invasion of extravascular tissues. PMID:23468987

  9. CD44 variant exon 6 expressions in colon cancer assessed by quantitative analysis using real time reverse transcriptase-polymerase chain reaction.

    PubMed

    Yamada, Yoichi; Itano, Naoki; Narimatsu, Hisashi; Kudo, Takashi; Hirohashi, Setsuo; Ochiai, Atsushi; Tohnai, Iwai; Ueda, Minoru; Kimata, Koji

    2003-01-01

    CD44 is a family of transmembrane glycoproteins that serve as a major receptor for hyaluronate and the splice variants play a very important role in tumor progression and metastasis. We examined the relationship between cancer progression and mRNA levels of CD44 variant exon 6 (CD44v6) in specimens of colon cancer at different diagnostic stages from 31 patients using real time RT-PCR analysis. Increased mRNA levels of CD44v6 were observed in 82% of the specimens in comparison with those in the corresponding non-cancerous tissue specimens. A statistically significant correlation between the CD44v6 expression and the cancerous state was found in most specimens at all Dukes stages. None of the other parameters were related to the expression in the cancerous specimens. Quantitative real time RT-PCR analysis showed that there was no correlation of CD44v6 expression with tumor progression, although CD44v6 is upregulated in transformation. Thus, CD44v6 expression may be a clinically useful indicator of colon cancer. PMID:14534719

  10. CD44(high)CD24(low) molecular signature determines the Cancer Stem Cell and EMT phenotype in Oral Squamous Cell Carcinoma.

    PubMed

    Ghuwalewala, Sangeeta; Ghatak, Dishari; Das, Pijush; Dey, Sanjib; Sarkar, Shreya; Alam, Neyaz; Panda, Chinmay K; Roychoudhury, Susanta

    2016-03-01

    Almost all epithelial tumours contain cancer stem-like cells, which possess a unique property of self-renewal and differentiation. In oral cancer, several biomarkers including cell surface molecules have been exploited for the identification of this highly tumorigenic population. Implicit is the role of CD44 in defining CSCs but CD24 is not well-explored. Here we show that CD44(high)CD24(low) cells isolated from the oral cancer cell lines, not only express stem cell related genes but also exhibit Epithelial-to-Mesenchymal transition (EMT) characteristics. This CD44(high)CD24(low) population gives rise to all other cell types upon differentiation. Typical Cancer Stem Cell (CSC) phenotypes like increased colony formation, sphere forming ability, migration and invasion were also confirmed in CD44(high)CD24(low) cells. Drug transporters were found to be over-expressed in CD44(high)CD24(low) sub-population thereby contributing to elevated chemo-resistance. To validate our findings in-vivo, we determined the relative expression of CD44 and CD24 in clinical samples of OSCC patients. CD44 expression was consistently high whereas CD24 showed significantly lower expression in tumour tissues. Further, the gene expression profile of the CSC and non-CSC population unravels the molecular pathways which may contribute to stemness. We conclude that CD44(high)CD24(low) represents cancer stem-like cells in Oral Squamous Cell Carcinoma. PMID:26926234

  11. RhoJ interacts with the GIT-PIX complex and regulates focal adhesion disassembly.

    PubMed

    Wilson, Eleanor; Leszczynska, Katarzyna; Poulter, Natalie S; Edelmann, Francesca; Salisbury, Victoria A; Noy, Peter J; Bacon, Andrea; Rappoport, Joshua Z; Heath, John K; Bicknell, Roy; Heath, Victoria L

    2014-07-15

    RhoJ is a Rho GTPase expressed in endothelial cells and tumour cells, which regulates cell motility, invasion, endothelial tube formation and focal adhesion numbers. This study aimed to further delineate the molecular function of RhoJ. Using timelapse microscopy RhoJ was found to regulate focal adhesion disassembly; small interfering RNA (siRNA)-mediated knockdown of RhoJ increased focal adhesion disassembly time, whereas expression of an active mutant (daRhoJ) decreased it. Furthermore, daRhoJ co-precipitated with the GIT-PIX complex, a regulator of focal adhesion disassembly. An interaction between daRhoJ and GIT1 was confirmed using yeast two-hybrid experiments, and this depended on the Spa homology domain of GIT1. GIT1, GIT2, β-PIX (also known as ARHGEF7) and RhoJ all colocalised in focal adhesions and depended on each other for their recruitment to focal adhesions. Functionally, the GIT-PIX complex regulated endothelial tube formation, with knockdown of both GIT1 and GIT2, or β-PIX phenocopying RhoJ knockdown. RhoJ-knockout mice showed reduced tumour growth and diminished tumour vessel density, identifying a role for RhoJ in mediating tumour angiogenesis. These studies give new insight into the molecular function of RhoJ in regulating cell motility and tumour vessel formation. PMID:24928894

  12. The hyaluronan receptors CD44 and RHAMM (CD168) form complexeswith ERK1,2, which sustain high basal motility in breast cancercells

    SciTech Connect

    Hamilton, Sara R.; Fard, Shireen F.; Paiwand, Frouz F.; Tolg,Cornelia; Veiseh, Mandana; Wang, Chao; McCarthy, James B.; Bissell, MinaJ.; Koropatnick, James; Turley, Eva A.

    2007-03-28

    CD44 is an integral hyaluronan receptor that can promote or inhibit motogenic signaling in tumor cells. Rhamm is a non-integral cell surface hyaluronan receptor (CD168) and intracellular protein that promotes cell motility in culture and its expression is strongly upregulated in diseases like arthritis and aggressive cancers. Here we describe an autocrine mechanism utilizing cell surface Rhamm/CD44 interactions to sustain rapid basal motility in invasive breast cancer cell lines. This mechanism requires endogenous hyaluronan synthesis and the formation of Rhamm/CD44/ERK1, 2 complexes. Motile/ invasive MDA-MB-231 and Ras-MCF10A cells produce more endogenous hyaluronan, cell surface CD44 and Rhamm, an oncogenic Rhamm isoform, and exhibit elevated basal activation of ERK1, 2 than less invasive MCF7 and MCF10A breast cancer cells. Furthermore, CD44, Rhamm and ERK1, 2 uniquely co-immunoprecipitate and co-localize in MDA-MB-231 and Ras-MCF10A cells. Rapid motility of the invasive cell lines requires interaction of hyaluronan with cells, activation of ERK1, 2 and the participation of both cell surface CD44 and Rhamm. Combinations of anti-CD44, anti-Rhamm antibodies and a MEK1 inhibitor (PD098059) have less-than-additive blocking effects, suggesting action of all three proteins on a common motogenic signaling pathway. Collectively, these results show that cell surface Rhamm and CD44 act together in a hyaluronan-dependent, autocrine mechanism to coordinate sustained signaling through ERK1, 2 leading to high basal motility of invasive breast cancer cells. Since CD44/Rhamm complexes are not evident in less motile cells, an effect of CD44 on tumor cell motility may depend in part on its ability to partner with additional proteins, in this case cell surface Rhamm.

  13. Endoglin regulates mural cell adhesion in the circulatory system.

    PubMed

    Rossi, Elisa; Smadja, David M; Boscolo, Elisa; Langa, Carmen; Arevalo, Miguel A; Pericacho, Miguel; Gamella-Pozuelo, Luis; Kauskot, Alexandre; Botella, Luisa M; Gaussem, Pascale; Bischoff, Joyce; Lopez-Novoa, José M; Bernabeu, Carmelo

    2016-04-01

    The circulatory system is walled off by different cell types, including vascular mural cells and podocytes. The interaction and interplay between endothelial cells (ECs) and mural cells, such as vascular smooth muscle cells or pericytes, play a pivotal role in vascular biology. Endoglin is an RGD-containing counter-receptor for β1 integrins and is highly expressed by ECs during angiogenesis. We find that the adhesion between vascular ECs and mural cells is enhanced by integrin activators and inhibited upon suppression of membrane endoglin or β1-integrin, as well as by addition of soluble endoglin (SolEng), anti-integrin α5β1 antibody or an RGD peptide. Analysis of different endoglin mutants, allowed the mapping of the endoglin RGD motif as involved in the adhesion process. In Eng (+/-) mice, a model for hereditary hemorrhagic telangectasia type 1, endoglin haploinsufficiency induces a pericyte-dependent increase in vascular permeability. Also, transgenic mice overexpressing SolEng, an animal model for preeclampsia, show podocyturia, suggesting that SolEng is responsible for podocytes detachment from glomerular capillaries. These results suggest a critical role for endoglin in integrin-mediated adhesion of mural cells and provide a better understanding on the mechanisms of vessel maturation in normal physiology as well as in pathologies such as preeclampsia or hereditary hemorrhagic telangiectasia. PMID:26646071

  14. Focal Adhesion Kinase regulates cell-cell contact formation in epithelial cells via modulation of Rho

    SciTech Connect

    Playford, Martin P.; Vadali, Kavita; Cai Xinming; Burridge, Keith; Schaller, Michael D.

    2008-10-15

    Focal Adhesion Kinase (FAK) is a non-receptor tyrosine kinase that plays a key role in cellular processes such as cell adhesion, migration, proliferation and survival. Recent studies have also implicated FAK in the regulation of cell-cell adhesion. Here, evidence is presented showing that siRNA-mediated suppression of FAK levels in NBT-II cells and expression of dominant negative mutants of FAK caused loss of epithelial cell morphology and inhibited the formation of cell-cell adhesions. Rac and Rho have been implicated in the regulation of cell-cell adhesions and can be regulated by FAK signaling. Expression of active Rac or Rho in NBT-II cells disrupted formation of cell-cell contacts, thus promoting a phenotype similar to FAK-depleted cells. The loss of intercellular contacts in FAK-depleted cells is prevented upon expression of a dominant negative Rho mutant, but not a dominant negative Rac mutant. Inhibition of FAK decreased tyrosine phosphorylation of p190RhoGAP and elevated the level of GTP-bound Rho. This suggests that FAK regulates cell-cell contact formation by regulation of Rho.

  15. Over expression of hyaluronan promotes progression of HCC via CD44-mediated pyruvate kinase M2 nuclear translocation

    PubMed Central

    Li, Jing-Huan; Wang, Ying-Cong; Qin, Cheng-Dong; Yao, Rong-Rong; Zhang, Rui; Wang, Yan; Xie, Xiao-Ying; Zhang, Lan; Wang, Yan-Hong; Ren, Zheng-Gang

    2016-01-01

    Hyaluronan is expressed in hepatocellular carcinoma (HCC) as HCC generally arises from a cirrhotic liver in which excessive production and accumulation of HA leads to developing cirrhosis. Though it has been suggested HA is involved in progression of HCC, the mechanisms underlying the connection between HA and HCC progression are unclear. Since increased aerobic glycolysis is a metabolic trait of malignant cells and HA-CD44 can modulate glucose metabolism, we aim to investigate the roles of PKM2, a key enzyme in glucose metabolism, in the HA-CD44 axis facilitated the progress of HCC. We shown PKM2 was required for HA-promoted HCC progression, which was not modulated by PKM2 kinase activity but by nuclear translocation of PKM2. PKM2 translocation was Erk (Thr202/Tyr204) phosphorylation dependent, which functioned at the downstream of HA-CD44 binding. Furthermore, elevated HA expression significantly correlated with PKM2 nuclear location and was an independent factors predicting poor HCC prognosis. In conclusions PKM2 nuclear translocation is required for mediating the described HA biological effects on HCC progression and our results imply that inhibition of HA may have therapeutic value in treating HCC. PMID:27186420

  16. Hyaluronic acid-coated solid lipid nanoparticles for targeted delivery of vorinostat to CD44 overexpressing cancer cells.

    PubMed

    Tran, Tuan Hiep; Choi, Ju Yeon; Ramasamy, Thiruganesh; Truong, Duy Hieu; Nguyen, Chien Ngoc; Choi, Han-Gon; Yong, Chul Soon; Kim, Jong Oh

    2014-12-19

    Hyaluronic acid (HA)-decorated solid lipid nanoparticles (SLNs) were developed for tumor-targeted delivery of vorinostat (VRS), a histone deacetylase inhibitor. HA, a naturally occurring polysaccharide, which specifically binds to the CD44 receptor, was coated on a cationic lipid core through electrostatic interaction. After the optimization process, HA-coated VRS-loaded SLNs (HA-VRS-SLNs) were spherical, core-shell nanoparticles, with small size (∼100 nm), negative charge (∼-9 mV), and narrow size distribution. In vitro release profile of HA-VRS-SLNs showed a typical bi-phasic pattern. In addition, the intracellular uptake of HA-VRS-SLNs was significantly enhanced in CD44 overexpressing cells, A549 and SCC-7 cells, but reduced when HA-VRS-SLNs were incubated with SCC-7 cells pretreated with HA or MCF-7 cells with low over-expressed CD44. Of particular importance, HA-VRS-SLNs were more cytotoxic than the free drug and VRS-SLNs in A549 and SCC-7 cells. In addition, HA shell provided longer blood circulation and reduced VRS clearance rate in rats, resulting in enhanced higher plasma concentration and bioavailability. These results clearly indicated the potential of the HA-functionalized lipid nanoparticle as a nano-sized drug formulation for chemotherapy. PMID:25263908

  17. Targeted and controlled drug delivery system loading artersunate for effective chemotherapy on CD44 overexpressing cancer cells.

    PubMed

    Tran, Tuan Hiep; Nguyen, Tuan Duc; Van Nguyen, Han; Nguyen, Hanh Thuy; Kim, Jong Oh; Yong, Chul Soon; Nguyen, Chien Ngoc

    2016-05-01

    Poly(D,L-lactic-co-glycolic acid) (PLGA) nanoparticles with negative surface charge were reversed to positive by cationic surfactant-DDAB before being coated with an anionic polymer, hyaluronic acid, to improve their site-specific intracellular delivery against CD44 receptor overexpressing cancer cells. Incorporating artesunate (ART)-a promising anticancer drug into PLGA/HA nanoparticles, is expected not only to overcome its poor aqueous solubility and stability but also enhance the activities. The obtained particles were characterized by dynamic light scattering, zeta potential measurements, and transmission electron microscopy (TEM). Cancer cell internalization of the NPs was evaluated by flow cytometry and cytotoxicity of the NPs was tested by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide assay. PLGA/HA nanoparticles showed greater extent of cellular uptake to SCC-7 and MCF-7 cells, indicating their affinity with CD44 receptor-mediated endocytosis. Almost 60 % of ART was released into the outer media after 48 h. In vitro fluorescence sorting demonstrated that PLGA/HA had highly efficient targeting and accumulation into CD44 receptor overexpression cells. The significant reduction in cell viability as well as greater induction of apoptosis suggested a potential in anticancer therapy of ART loaded PLGA/HA. PMID:27015824

  18. Hyaluronic Acid Engineered Nanomicelles Loaded with 3,4-Difluorobenzylidene Curcumin for Targeted Killing of CD44+ Stem-Like Pancreatic Cancer Cells.

    PubMed

    Kesharwani, Prashant; Banerjee, Sanjeev; Padhye, Subhash; Sarkar, Fazlul H; Iyer, Arun K

    2015-09-14

    Cancer stem-like cells (CSLCs) play a pivotal role in acquiring multidrug resistant (MDR) phenotypes. It has been established that pancreatic cancers overexpressing CD44 receptors (a target of hyaluronic acid; HA) is one of the major contributors for causing MDR. Therefore, targeted killing of CD44 expressing tumor cells using HA based active targeting strategies may be beneficial for eradicating MDR-pancreatic cancers. Here, we report the synthesis of a new HA conjugate of copoly(styrene maleic acid) (HA-SMA) that could be engineered to form nanomicelles with a potent anticancer agent, 3,4-difluorobenzylidene curcumin (CDF). The anticancer activity of CDF loaded nanomicelles against MiaPaCa-2 and AsPC-1 human pancreatic cancer cells revealed dose-dependent cell killing. Results of cellular internalization further confirmed better uptake of HA engineered nanomicelles in triple-marker positive (CD44+/CD133+/EpCAM+) pancreatic CSLCs compared with triple-marker negative (CD44-/CD133-/EpCAM-) counterparts. More importantly, HA-SMA-CDF exhibited superior anticancer response toward CD44+ pancreatic CSLCs. Results further confirmed that triple-marker positive cells treated with HA-SMA-CDF caused significant reduction in CD44 expression and marked inhibition of NF-κB that in-turn can mitigate their proliferative and invasive behavior. Conclusively, these results suggest that the newly developed CD44 targeted nanomicelles may have great implications in treating pancreatic cancers including the more aggressive pancreatic CSLCs. PMID:26302089

  19. CD44 variant 9 is a potential biomarker of tumor initiating cells predicting survival outcome in hepatitis C virus-positive patients with resected hepatocellular carcinoma.

    PubMed

    Kakehashi, Anna; Ishii, Naomi; Sugihara, Eiji; Gi, Min; Saya, Hideyuki; Wanibuchi, Hideki

    2016-05-01

    This study investigated whether the expression of CD44 variant 9 (CD44v9) might be a functional marker of tumor-initiating stem-like cells in primary hepatocellular carcinomas (HCCs) of hepatitis C virus (HCV)(+) patients and provide an indicator of patient survival, as well as associated mechanisms. A total of 90 HCV(+) HCC patients who underwent surgery from 2006 to 2011 were enrolled and monitored for 2-8 years. Expression of CD44v9 was validated immunohistochemically in all HCCs, followed by comparative proteome, survival, and clinicopathological analyses. CD44 variant 8--10 was further evaluated in diethylnitrosamine-induced HCCs of C57Bl/6J mice. Focally localized CD44v(+) cells with a membranous staining pattern were detected in human HCV(+) and mouse HCCs. CD44v9(+) cells of HCCs were predominantly negative for Ki67 and P-p38, indicating decrease of cell proliferation in the CD44v9(+) tumor cell population, likely to be related to suppression of intracellular oxidative stress due to activation of Nrf2-mediated signaling, DNA repair, and inhibition of xenobiotic metabolism. CD44v9 IHC evaluation in 90 HCV(+) HCC cases revealed that positive expression was significantly associated with poor overall and recurrence-free survival, a younger age, poor histological differentiation of HCCs, and high alkaline phosphatase levels compared with patients with negative expression. CD44v9 is concluded to be a potential biomarker of tumor-initiating stem-like cells and a prognostic marker in HCV(+) HCC patients associated with Nrf2-mediated resistance to oxidative stress. PMID:26882440

  20. Vinculin acts as a sensor in lipid regulation of adhesion-site turnover.

    PubMed

    Chandrasekar, Indra; Stradal, Theresia E B; Holt, Mark R; Entschladen, Frank; Jockusch, Brigitte M; Ziegler, Wolfgang H

    2005-04-01

    The dynamics of cell adhesion sites control cell morphology and motility. Adhesion-site turnover is thought to depend on the local availability of the acidic phospholipid phosphatidylinositol-4,5-bisphosphate (PIP(2)). PIP(2) can bind to many cell adhesion proteins such as vinculin and talin, but the consequences of this interaction are poorly understood. To study the significance of phospholipid binding to vinculin for adhesion-site turnover and cell motility, we constructed a mutant, vinculin-LD, deficient in acidic phospholipid binding yet with functional actin-binding sites. When expressed in cells, vinculin-LD was readily recruited to adhesion sites, as judged by fluorescence recovery after photobleaching (FRAP) analysis, but cell spreading and migration were strongly impaired, and PIP(2)-dependent disassembly of adhesions was suppressed. Thus, PIP(2) binding is not essential for vinculin activation and recruitment, as previously suggested. Instead, we propose that PIP(2) levels can regulate the uncoupling of adhesion sites from the actin cytoskeleton, with vinculin functioning as a sensor. PMID:15769850

  1. Lubricin/Proteoglycan 4 Binding to CD44 Receptor: A Mechanism of Lubricin’s suppression of Pro-inflammatory Cytokine Induced Synoviocyte Proliferation

    PubMed Central

    Al-Sharif, Afnan; Jamal, Maha; Zhang, Ling; Larson, Katherine; Schmidt, Tannin; Jay, Gregory; Elsaid, Khaled

    2015-01-01

    Objective To evaluate recombinant human proteoglycan 4 (rhPRG4) binding to CD44 receptor and its consequence on cytokine induced synoviocyte proliferation. Methods rhPRG4 binding to CD44 and competition with high molecular weight hyaluronic acid (HMW HA) was evaluated using a direct enzyme linked immunosorbent assay (ELISA) and surface plasmon resonance. Sialidase-A and O-glycosidase digestion of rhPRG4 was performed and CD44 binding was evaluated using ELISA. Rheumatoid arthritis fibroblast-like synoviocytes (RA-FLS) were stimulated with interleukin-1 beta (IL-1β) or tumor necrosis factor alpha (TNF-α) for 48 hours in the presence or absence of rhPRG4 or HMW HA at 20, 40 and 80μg/ml and cell proliferation was measured. CD44 contribution was assessed by co-incubation with a CD44 antibody (IM7). The anti-proliferative effect of rhPRG4 was investigated following treatment of Prg4−/− synoviocytes with IL-1β or TNF-α in the presence or absence of IM7. Results rhPRG4 binds CD44 and interferes with HMW HA CD44 binding. Removal of sialic acid and O-glycosylations significantly increased CD44 binding by rhPRG4 (p<0.001). rhPRG4 and HMW HA at 40 and 80μg/ml significantly suppressed IL-1β induced RA-FLS proliferation (p<0.05). rhPRG4 at 20, 40 and 80μg/ml significantly suppressed TNF-α induced RA-FLS proliferation (p<0.05). CD44 neutralization reversed the effect of rhPRG4 on IL-1β and TNF-α stimulated RA-FLS and the effect of HMW HA on IL-1β stimulated RA-FLS. rhPRG4 inhibited cytokine-induced proliferation of Prg4−/− synoviocytes which could be prevented by blocking CD44. Conclusion Lubricin is a novel putative ligand for CD44 and may control synoviocyte overgrowth in inflammatory arthropathies via a CD44-mediated mechanism. PMID:25708025

  2. Blocking the Adhesion Cascade at the Premetastatic Niche for Prevention of Breast Cancer Metastasis

    PubMed Central

    Kang, Shin-Ae; Hasan, Nafis; Mann, Aman P; Zheng, Wei; Zhao, Lichao; Morris, Lynsie; Zhu, Weizhu; Zhao, Yan D; Suh, K Stephen; Dooley, William C; Volk, David; Gorenstein, David G; Cristofanilli, Massimo; Rui, Hallgeir; Tanaka, Takemi

    2015-01-01

    Shear-resistant adhesion and extravasation of disseminated cancer cells at the target organ is a crucial step in hematogenous metastasis. We found that the vascular adhesion molecule E-selectin preferentially promoted the shear-resistant adhesion and transendothelial migration of the estrogen receptor (ER)–/CD44+ hormone-independent breast cancer cells, but not of the ER+/CD44-/low hormone-dependent breast cancer cells. Coincidentally, CD44+ breast cancer cells were abundant in metastatic lung and brain lesions in ER– breast cancer, suggesting that E-selectin supports hematogenous metastasis of ER–/CD44+ breast cancer. In an attempt to prevent hematogenous metastasis through the inhibition of a shear-resistant adhesion of CD44+ cancer cells to E-selectin-expressing blood vessels on the premetastatic niche, an E-selectin targeted aptamer (ESTA) was developed. We demonstrated that a single intravenous injection of ESTA reduced metastases to a baseline level in both syngeneic and xenogeneic forced breast cancer metastasis models without relocating the site of metastasis. The effect of ESTA was absent in E-selectin knockout mice, suggesting that E-selectin is a molecular target of ESTA. Our data highlight the potential application of an E-selectin antagonist for the prevention of hematogenous metastasis of ER–/CD44+ breast cancer. PMID:25815697

  3. Neuropilin-2 regulates α6β1 integrin in the formation of focal adhesions and signaling.

    PubMed

    Goel, Hira Lal; Pursell, Bryan; Standley, Clive; Fogarty, Kevin; Mercurio, Arthur M

    2012-01-15

    The neuropilins (NRPs) contribute to the function of cancer cells in their capacity as VEGF receptors. Given that NRP2 is induced in breast cancer and correlates with aggressive disease, we examined the role of NRP2 in regulating the interaction of breast cancer cells with the ECM. Using epithelial cells from breast tumors, we defined NRP2(high) and NRP2(low) populations that differed in integrin expression and adhesion to laminin. Specifically, the NRP2(high) population adhered more avidly to laminin and expressed high levels of the α6β1 integrin than the NRP2(low) population. The NRP2(high) population formed numerous focal adhesions on laminin that were not seen in the NRP2(low) population. These results were substantiated using breast carcinoma cell lines that express NRP2 and α6β1 integrin. Depletion experiments revealed that adhesive strength on laminin but not collagen is dependent on NRP2, and that VEGF is needed for adhesion on laminin. A specific interaction between NRP2 and α6β1 integrin was detected by co-immunoprecipitation. NRP2 is necessary for focal adhesion formation on laminin and for the association of α6β1 integrin with the cytoskeleton. NRP2 also facilitates α6β1-integrin-mediated activation of FAK and Src. Unexpectedly, we discovered that NRP2 is located in focal adhesions on laminin. The mechanism by which NRP2 regulates the interaction of α6β1 integrin with laminin to form focal adhesions involves PKC activation. Together, our data reveal a new VEGF-NRP2 signaling pathway that activates the α6β1 integrin and enables it to form focal adhesions and signal. This pathway is important in the pathogenesis of breast cancer. PMID:22302985

  4. Selective Hyaluronan-CD44 Signaling Promotes miRNA-21 Expression and Interacts with Vitamin D Function during Cutaneous Squamous Cell Carcinomas Progression Following UV Irradiation.

    PubMed

    Bourguignon, Lilly Y W; Bikle, Daniel

    2015-01-01

    Hyaluronan (HA), the major extracellular matrix component, is often anchored to CD44, a family of structurally/functionally important cell surface receptors. Recent results indicate that UV irradiation (UVR)-induced cutaneous squamous cell carcinomas (SCC) overexpress a variety of CD44 variant isoforms (CD44v), with different CD44v isoforms appear to confer malignant SCC properties. UVR also stimulates HA degradation in epidermal keratinocytes. Both large HA polymers and their UVR-induced catabolic products (small HA) selectively activate CD44-mediated cellular signaling in normal keratinocytes and SCC cells, with all of the downstream processes being mediated by RhoGTPases (e.g., Rac1 and Rho). Importantly, we found that the hormonally active form of vitamin D 1,25(OH)2D3 not only prevents the UVR-induced small HA activation of abnormal keratinocyte behavior and SCC progression, but also enhances large HA stimulation of normal keratinocyte activities and epidermal function(s). The aim of this hypothesis and theory article is to question whether matrix HA and its UVR-induced catabolic products (e.g., large and small HA) can selectively activate CD44-mediated cellular signaling such as GTPase (Rac and RhA) activation. We suggested that large HA-CD44 interaction promotes Rac-signaling and normal keratinocyte differentiation (lipid synthesis), DNA repair, and keratinocyte survival function. Conversely, small HA-CD44 interaction stimulates RhoA activation, NFκB/Stat-3 signaling, and miR-21 production, resulting in inflammation and proliferation as well as SCC progression. We also question whether vitamin D treatment displays any effect on small HA-CD44v-mediated RhoA signaling, inflammation, and SCC progression, as well as large HA-CD44-mediated differentiation, DNA repair, keratinocyte survival, and normal keratinocyte function. In addition, we discussed that the topical application of signaling perturbation agents (e.g., Y27623, a ROK inhibitor) may be used to treat

  5. The anti-CD74 humanized monoclonal antibody, milatuzumab, which targets the invariant chain of MHC II complexes, alters B-cell proliferation, migration, and adhesion molecule expression

    PubMed Central

    2012-01-01

    Introduction Targeting CD74 as the invariant chain of major histocompatibility complexes (MHC) became possible by the availability of a specific humanized monoclonal antibody, milatuzumab, which is under investigation in patients with hematological neoplasms. CD74 has been reported to regulate chemo-attractant migration of macrophages and dendritic cells, while the role of CD74 on peripheral naïve and memory B cells also expressing CD74 remains unknown. Therefore, the current study addressed the influence of milatuzumab on B-cell proliferation, chemo-attractant migration, and adhesion molecule expression. Methods Surface expression of CD74 on CD27- naïve and CD27+ memory B cells as well as other peripheral blood mononuclear cells (PBMCs) obtained from normals, including the co-expression of CD44, CXCR4, and the adhesion molecules CD62L, β7-integrin, β1-integrin and CD9 were studied after binding of milatuzumab using multicolor flow cytometry. The influence of the antibody on B-cell proliferation and migration was analyzed in vitro in detail. Results In addition to monocytes, milatuzumab also specifically bound to human peripheral B cells, with a higher intensity on CD27+ memory versus CD27- naïve B cells. The antibody reduced B-cell proliferation significantly but moderately, induced enhanced spontaneous and CXCL12-dependent migration together with changes in the expression of adhesion molecules, CD44, β7-integrin and CD62L, mainly of CD27- naïve B cells. This was independent of macrophage migration-inhibitory factor as a ligand of CD74/CD44 complexes. Conclusions Milatuzumab leads to modestly reduced proliferation, alterations in migration, and adhesion molecule expression preferentially of CD27- naïve B cells. It thus may be a candidate antibody for the autoimmune disease therapy by modifying B cell functions. PMID:22404985

  6. Intravenous Immunoglobulin Suppresses Abortion Relates to an Increase in the CD44bright NK Subset in Recurrent Pregnancy Loss Model Mice.

    PubMed

    Tanaka, Jun; Kitashoji, Akira; Fukunaga, Yuki; Kashihara, Junichi; Nakano, Atsushi; Kamizono, Akihito

    2016-08-01

    Recurrent pregnancy loss (RPL), which mostly is of unknown etiology (unexplained RPL, uRPL), is defined as three or more consecutive spontaneous abortions. Some women with uRPL display a higher fraction and cytotoxicity of natural killer (NK) cells in the periphery and endometrium. Therefore, some uRPL cases have been explained by autoimmune abnormalities. The efficacy of intravenous immunoglobulin (IVIg) for uRPL has been confirmed in several clinical trials; however, its mechanism remains unknown, mainly because the abortion mechanism remains to be elucidated. In the present study, we analyzed the mechanisms of both abortion and IVIg action using a uRPL mouse model in which abortion was induced by lipopolysaccharide injection. IVIg attenuated the abortion rate in the uRPL model mice. The suppressive effect of IVIg was maximized by high dose administration early after lipopolysaccharide injection. Specifically, we discovered the presence of two distinct uterine NK (uNK) subsets: CD44(bright) and CD44(mid) In uRPL model mice, we observed an increase in the number of CD44(bright) uNK cells, while the CD44(mid) uNK subset remained unchanged. Furthermore, when abortion was reduced by IVIg administration, the cell number of the CD44(bright) uNK subset did not increase, which might allow differentiating pathological from normal uNK cells based on CD44 expression. Based on these results, we propose not only an effective administration protocol of IVIg to the uRPL model mice, but also a novel mechanism of abortion related to the increase in the CD44(bright) subset and of IVIg, which suppresses the increase of the CD44(bright) subset. PMID:27335067

  7. Hyaluronan-decorated polymer nanoparticles targeting the CD44 receptor for the combined photo/chemo-therapy of cancer

    NASA Astrophysics Data System (ADS)

    Maiolino, Sara; Moret, Francesca; Conte, Claudia; Fraix, Aurore; Tirino, Pasquale; Ungaro, Francesca; Sortino, Salvatore; Reddi, Elena; Quaglia, Fabiana

    2015-03-01

    In the attempt to develop novel concepts in designing targeted nanoparticles for combination therapy of cancer, we propose here CD44-targeted hyaluronan-decorated double-coated nanoparticles (dcNPs) delivering the lipophilic chemotherapeutic docetaxel (DTX) and an anionic porphyrin (TPPS4). dcNPs are based on electrostatic interactions between a negative DTX-loaded nanoscaffold of poly(lactide-co-glycolide), a polycationic shell of polyethyleneimine entangling negatively-charged TPPS4 and finally decorated with hyaluronan (HA) to promote internalization through CD44 receptor-mediated endocytosis. DTX/TPPS4-dcNPs, prepared through layer-by-layer deposition, showed a hydrodynamic diameter of around 180 nm, negative zeta potential and efficient loading of both DTX and TPPS4. DTX/TPPS4-dcNPs were freeze-dried with trehalose giving a powder that could be easily dispersed in different media. Excellent stability of dcNPs in specific salt- and protein-containing media was found. Spectroscopic behavior of DTX/TPPS4-dcNPs demonstrated a face-to-face arrangement of the TPPS4 units in non-photoresponsive H-type aggregates accounting for an extensive aggregation of the porphyrin embedded in the shell. Experiments in MDA-MB-231 cells overexpressing the CD44 receptor demonstrated a 9.4-fold increase in the intracellular level of TPPS4 delivered from dcNPs as compared to free TPPS4. Light-induced death increased tremendously in cells that had been treated with a combination of TPPS4 and DTX delivered through dcNPs as compared with free drugs, presumably due to efficient uptake and co-localization inside the cells. In perspective, the strategy proposed here to target synergistic drug combinations through HA-decorated nanoparticles seems very attractive to improve the specificity and efficacy of cancer treatment.In the attempt to develop novel concepts in designing targeted nanoparticles for combination therapy of cancer, we propose here CD44-targeted hyaluronan-decorated double

  8. REGULATION OF CONCEPTUS ADHESION BY ENDOMETRIAL CXC CHEMOKINES DURING THE IMPLANTATION PERIOD IN SHEEP

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To gain a better understanding of biochemical mechanisms of conceptus adhesion to the maternal endometrium in ruminant ungulates, the present study was performed to clarify roles of chemokines and extracellular matrix (ECM) components in the regulation of ovine blastocyst attachment to the endometri...

  9. Hyaluronic acid-conjugated polyamidoamine dendrimers for targeted delivery of 3,4-difluorobenzylidene curcumin to CD44 overexpressing pancreatic cancer cells.

    PubMed

    Kesharwani, Prashant; Xie, Lingxiao; Banerjee, Sanjeev; Mao, Guangzhao; Padhye, Subhash; Sarkar, Fazlul H; Iyer, Arun K

    2015-12-01

    The current study was aimed to develop a targeted dendrimer formulation of 3, 4-difluorobenzylidene curcumin (CDF) and evaluate its potential in CD44 targeted therapy for pancreatic cancer. Using amine terminated fourth generation poly(amidoamine) (PAMAM) dendrimer nanocarrier and hyaluronic acid (HA) as a targeting ligand, we engineered a CD44-targeted PAMAM dendrimer (HA-PAMAM) formulation of CDF. The resulting dendrimer nanosystem (HA-PAMAM-CDF) had a particle size and surface charge of 9.3 ± 1.5 nm and -7.02 ± 9.53 mV, respectively. When CD44 receptor overexpressing MiaPaCa-2 and AsPC-1 human pancreatic cancer cells were treated with HA-PAMAM-CDF, a dose-dependent cytotoxicity was observed. Furthermore, blocking the CD44 receptors present on the MiaPaCa-2 cells using free excess soluble HA prior to treatment with HA-PAMAM-CDF nano-formulation resulted in 1.71 fold increase in the IC50 value compared to non-targeted formulation (PAMAM-CDF), confirming target specificity of HA-PAMAM-CDF. Additionally, HA-PAMAM-CDF formulation when compared to PAMAM-CDF, displayed higher cellular uptake in MiaPaCa-2 cancer cell lines as shown by fluorescence studies. In summary, the novel CD44 targeted dendrimer based nanocarriers appear to be proficient in mediating site-specific delivery of CDF via CD44 receptors, with an improved therapeutic margin and safety. PMID:26440757

  10. Adhesion-mediated self-renewal abilities of Ph+ blastoma cells

    SciTech Connect

    Funayama, Keiji; Saito-Kurimoto, Yumi; Ebihara, Yasuhiro; Shimane, Miyuki; Nomura, Hitoshi; Tsuji, Ko-ichiro; Asano, Shigetaka

    2010-05-28

    The Philadelphia chromosome-positive blastoma, maintained by serial subcutaneous transplantation in nude mice, is a highly proliferating biological mass consisting of homogenous CD34{sup +}CD38{sup -} myeloblastoid cells. These cells newly evolved from pluripotent leukemia stem cells of chronic myeloid leukemia in the chronic phase. Therefore, this mass may provide a unique tool for better understanding cellular and molecular mechanisms of self-renewal of leukemia stem cells. In this paper, we demonstrated that intravenously injected blastoma cells can cause Ph+ blastic leukemia with multiple invasive foci in NOD/SCID mice but not in nude mice. In addition, using an in vitro culture system, we clearly showed that blastoma cell adhesion to OP9 stromal cells accelerates blastoma cell proliferation that is associated with up-regulation of BMI1 gene expression; increased levels of {beta}-catenin and the Notch1 intra-cellular domain; and changed the expression pattern of variant CD44 forms, which are constitutively expressed in these blastoma cells. These findings strongly suggest that adhesion of leukemic stem cells to stromal cells via CD44 might be indispensable for their cellular defense against attack by immune cells and for maintenance of their self-renewal ability.

  11. Lysophosphatidic acid regulates adhesion molecules and enhances migration of human oral keratinocytes.

    PubMed

    Thorlakson, Hong H; Schreurs, Olav; Schenck, Karl; Blix, Inger J S

    2016-04-01

    Oral keratinocytes are connected via cell-to-cell adhesions to protect underlying tissues from physical and bacterial damage. Lysophosphatidic acids (LPAs) are a family of phospholipid mediators that have the ability to regulate gene expression, cytoskeletal rearrangement, and cytokine/chemokine secretion, which mediate proliferation, migration, and differentiation. Several forms of LPA are found in saliva and gingival crevicular fluid, but it is unknown how they affect human oral keratinocytes (HOK). The aim of the present study was therefore to examine how different LPA forms affect the expression of adhesion molecules and the migration and proliferation of HOK. Keratinocytes were isolated from gingival biopsies obtained from healthy donors and challenged with different forms of LPA. Quantitative real-time RT-PCR, immunocytochemistry, and flow cytometry were used to analyze the expression of adhesion molecules. Migration and proliferation assays were performed. Lysophosphatidic acids strongly promoted expression of E-cadherin and occludin mRNAs and translocation of E-cadherin protein from the cytoplasm to the membrane. Occludin and claudin-1 proteins were up-regulated by LPA. Migration of HOK in culture was increased, but proliferation was reduced, by the addition of LPA. This indicates that LPA can have a role in the regulation of the oral epithelial barrier by increasing the expression of adhesion molecules of HOK, by promotion of migration and by inhibition of proliferation. PMID:26913569

  12. The Regulation of Traction Force in Relation to Cell Shape and Focal Adhesions

    PubMed Central

    Rape, Andrew; Guo, Wei-hui; Wang, Yu-li

    2011-01-01

    Mechanical forces provide critical inputs for proper cellular functions. The interplay between the generation of, and response to, mechanical forces regulate such cellular processes as differentiation, proliferation, and migration. We postulate that adherent cells respond to a number of physical and topographical factors, including cell size and shape, by detecting the magnitude and/or distribution of traction forces under different conditions. To address this possibility we introduce a new simple method for precise micropatterning of hydrogels, and then apply the technique to systematically investigate the relationship between cell geometry, focal adhesions, and traction forces in cells with a series of spread areas and aspect ratios. Contrary to previous findings, we find that traction force is not determined primarily by the cell spreading area but by the distance from cell center to the perimeter. This distance in turn controls traction forces by regulating the size of focal adhesions, such that constraining the size of focal adhesions by micropatterning can override the effect of geometry. We propose that the responses of traction forces to center-periphery distance, possibly through a positive feedback mechanism that regulates focal adhesions, provide the cell with the information on its own shape and size. A similar positive feedback control may allow cells to respond to a variety of physical or topographical signals via a unified mechanism. PMID:21163521

  13. Cucurbitacin I suppressed stem-like property and enhanced radiation-induced apoptosis in head and neck squamous carcinoma--derived CD44(+)ALDH1(+) cells.

    PubMed

    Chen, Yi-Wei; Chen, Kuan-Hsuan; Huang, Pin-I; Chen, Yu-Chih; Chiou, Guang-Yu; Lo, Wen-Liang; Tseng, Ling-Ming; Hsu, Han-Sui; Chang, Kuo-Wei; Chiou, Shih-Hwa

    2010-11-01

    Head and neck squamous cell carcinoma (HNSCC) is a prevalent cancer worldwide. Signal transducers and activators of transcription 3 (STAT3) signaling is reported to promote tumor malignancy and recurrence in HNSCC. Cucurbitacins, triterpenoid derivatives, are strong STAT3 inhibitors with anticancer properties. Recent studies have shown aldehyde dehydrogenase 1 (ALDH1) to be a marker of cancer stem cells (CSC) in HNSCC. The aim of this study was to investigate the therapeutic effect of cucurbitacin I in HNSCC-derived CSCs. Using immunohistochemical analysis, we firstly showed that CD44, ALDH1, and phosphorylated STAT3 (p-STAT3) were higher in high-grade HNSCCs, and that triple positivity for CD44/ALDH1/p-STAT3 indicated a worse prognosis for HNSCC patients. Secondly, CD44(+)ALDH1(+) cells isolated from seven HNSCC patients showed greater tumorigenicity, radioresistance, and high expression of stemness (Bmi-1/Oct-4/Nanog) and epithelial-mesenchymal-transitional (Snail/Twist) genes as p-STAT3 level increased. Furthermore, we found that cucurbitacin I (JSI-124) can effectively inhibit the expression of p-STAT3 and capacities for tumorigenicity, sphere formation, and radioresistance in HNSCC-CD44(+)ALDH1(+). Notably, 150 nmol/L cucurbitacin I effectively blocked STAT3 signaling and downstream survivin and Bcl-2 expression, and it induced apoptosis in HNSCC-CD44(+)ALDH1(+). Moreover, microarray data indicated that 100 nmol/L cucurbitacin I facilitated CD44(+)ALDH1(+) cells to differentiate into CD44⁻ALDH1⁻ and enhanced the radiosensitivity of HNSCC-CD44(+)ALDH1(+). Xenotransplant experiments revealed that cucurbitacin I combined with radiotherapy significantly suppressed tumorigenesis and lung metastasis and further improved the survival rate in HNSCC-CD44(+)ALDH1(+)-transplanted immunocompromised mice. Taken together, our data show that cucurbitacin I, STAT3 inhibitor, reduces radioresistant, distant-metastatic, and CSC-like properties of HNSCC-CD44(+)ALDH1(+) cells

  14. Alkaline ceramidase 2 regulates β1 integrin maturation and cell adhesion

    PubMed Central

    Sun, Wei; Hu, Wei; Xu, Ruijuan; Jin, Junfei; Szulc, Zdzislaw M.; Zhang, Guofeng; Galadari, Sehamuddin H.; Obeid, Lina M.; Mao, Cungui

    2009-01-01

    The polypeptide core of the integrin β1 subunit (β1) is glycosylated sequentially in the endoplasmic reticulum and the Golgi complex to form β1 precursor and mature β1, respectively. The β1 precursor to mature β1 conversion, termed β1 maturation, regulates the cell surface levels and function of β1-containing integrins, β1 integrins. Here we demonstrate that the human alkaline ceramidase 2 (ACER2), a Golgi enzyme, regulates β1 maturation by controlling the generation of sphingosine. ACER2 overexpression inhibited β1 maturation, thus leading to a decrease in the levels of mature β1 in T-REx HeLa cells, whereas RNA interference-mediated knockdown of ACER2 enhanced β1 maturation in MCF-7 cells. ACER2 overexpression decreased the cell surface levels of β1 integrins, thus inhibiting cell adhesion to fibronectin or collagen, whereas ACER2 knockdown has the opposite effects. Treatment with all-trans retinoic acid (ATRA) increased both the expression of ACER2 and the generation of sphingosine in HeLa cells and inhibited β1 maturation. ACER2 knockdown attenuated the inhibitory effects of ATRA on both β1 maturation and cell adhesion. In contrast, treatment with phorbol myristate acetate (PMA), a protein kinase C activator, decreased the expression of ACER2 and sphingosine in T-REx HeLa cells, thus enhancing β1 maturation. ACER2 overexpression inhibited the stimulatory effects of PMA on both β1 maturation and cell adhesion. These results suggest that the ACER2/sphingosine pathway plays an important role in regulating β1 maturation and cell adhesion mediated by β1 integrins.—Sun, W., Hu, W., Xu, R., Jin, J., Szulc, Z. M., Zhang, G., Galadari, S. H., Obeid, L. M, Mao, C. Alkaline ceramidase 2 regulates β1 integrin maturation and cell adhesion. PMID:18945876

  15. Environmental alteration and phenotypic regulation of Candida albicans adhesion to plastic.

    PubMed Central

    Kennedy, M J; Rogers, A L; Yancey, R J

    1989-01-01

    The adhesion of Candida albicans to plastic was examined after growth in two chemically defined media, Lee-Buckley-Campbell (LBC) and yeast nitrogen base (YNB), by binding isotherms, Langmuir isotherms, and Scatchard plots, and the number of binding sites (N) and the affinity constants (K) were calculated. K and N were twofold and fourfold higher, respectively, after growth in LBC compared with that in YNB. A comparison of adhesion in different assay solutions gave similar results, with the solution given to dehydrated patients (5% glucose in 0.45% NaCl [D5.45]) allowing for the highest K and the largest N. Scatchard curves for both LBC- and YNB-grown cells had negative slopes, which is supportive evidence for the view that negative cooperativity is involved in the binding process. Additional experiments to examine the role of cell surface hydrophobicity in adhesion to plastic were conducted with the white and opaque phenotypes of C. albicans. There was no significant difference in the adhesion of these phenotypes to plastic, although the opaque phenotype was significantly more hydrophobic. Adhesion, but not cell surface hydrophobicity, of both phenotypes was significantly greater in D5.45. Moreover, relatively hydrophilic mycelial forms of C. albicans were found to attach only when D5.45 was used as the assay medium and, in contrast to yeast-phase cells, were insensitive to reduced adhesion by nonionic detergents. These results suggest that the adhesion of C. albicans to plastic is regulated by environmental circumstances and the phenotypic state of the organism. PMID:2680985

  16. AF1q is a novel TCF7 co-factor which activates CD44 and promotes breast cancer metastasis.

    PubMed

    Park, Jino; Schlederer, Michaela; Schreiber, Martin; Ice, Ryan; Merkel, Olaf; Bilban, Martin; Hofbauer, Sebastian; Kim, Soojin; Addison, Joseph; Zou, Jie; Ji, Chunyan; Bunting, Silvia T; Wang, Zhengqi; Shoham, Menachem; Huang, Gang; Bago-Horvath, Zsuzsanna; Gibson, Laura F; Rojanasakul, Yon; Remick, Scot; Ivanov, Alexey; Pugacheva, Elena; Bunting, Kevin D; Moriggl, Richard; Kenner, Lukas; Tse, William

    2015-08-21

    AF1q is an MLL fusion partner that was identified from acute myeloid leukemia (AML) patients with t (1; 11) (q21; q23) chromosomal abnormality. The function of AF1q is not yet fully known, however, elevated AF1q expression is associated with poor clinical outcomes in various malignancies. Here, we show that AF1q specifically binds to T-cell-factor-7 (TCF7) in the Wnt signaling pathway and results in transcriptional activation of CD44 as well as multiple downstream targets of the TCF7/LEF1. In addition, enhanced AF1q expression promotes breast cancer cell proliferation, migration, mammosphere formation, and chemo-resistance. In xenograft models, enforced AF1q expression in breast cancer cells also promotes liver metastasis and lung colonization. In a cohort of 63 breast cancer patients, higher percentages of AF1q-positive cancer cells in primary sites were associated with significantly poorer overall survival (OS), disease-free survival (DFS), and brain metastasis-free survival (b-MFS). Using paired primary/metastatic samples from the same patients, we demonstrate that AF1q-positive breast cancer cells become dynamically dominant in the metastatic sites compared to the primary sites. Our findings indicate that breast cancer cells with a hyperactive AF1q/TCF7/CD44 regulatory axis in the primary sites may represent "metastatic founder cells" which have invasive properties. PMID:26079538

  17. CD44 and TGFbeta1 synergise to induce expression of a functional NADPH oxidase in promyelocytic cells.

    PubMed

    Basoni, Caroline; Reuzeau, Edith; Croft, Daniel; Génot, Elisabeth; Kramer, Ijsbrand M

    2006-05-01

    Bone marrow stromal cells produce large amounts of extracellular matrix and cytokines. Amongst them, hyaluronan, a glycosaminoglycan and ligand for the cell surface molecule CD44, and TGFbeta1, a cytokine particularly important in monocyte differentiation. We have studied in vitro the role of hyaluronan and TGFbeta1 in the differentiation process of U937 monocytic progenitor cells. We provide evidence that, in the presence of whole blood-derived serum, the addition of hyaluronan is sufficient to induce the expression of NADPH-oxidase components but not of other monocytic markers (CD14, CD11b, and VLA-4). In the presence of plasma-derived serum, besides hyaluronan, the additional presence of TGFbeta1 was required for the expression of all of the components of the NADPH oxidase. We further show that hyaluronan mediates its effect through CD44. We conclude that cell matrix factors act cooperatively with cytokines to induce the expression of the components of the NADPH-oxidase in monocytic progenitor cells. PMID:16554035

  18. AF1q is a novel TCF7 co-factor which activates CD44 and promotes breast cancer metastasis

    PubMed Central

    Park, Jino; Schlederer, Michaela; Schreiber, Martin; Ice, Ryan; Merkel, Olaf; Bilban, Martin; Hofbauer, Sebastian; Kim, Soojin; Addison, Joseph; Zou, Jie; Ji, Chunyan; Bunting, Silvia T.; Wang, Zhengqi; Shoham, Menachem; Huang, Gang; Bago-Horvath, Zsuzsanna; Gibson, Laura F.; Rojanasakul, Yon; Remick, Scot; Ivanov, Alexey; Pugacheva, Elena; Bunting, Kevin D.; Moriggl, Richard

    2015-01-01

    AF1q is an MLL fusion partner that was identified from acute myeloid leukemia (AML) patients with t (1; 11) (q21; q23) chromosomal abnormality. The function of AF1q is not yet fully known, however, elevated AF1q expression is associated with poor clinical outcomes in various malignancies. Here, we show that AF1q specifically binds to T-cell-factor-7 (TCF7) in the Wnt signaling pathway and results in transcriptional activation of CD44 as well as multiple downstream targets of the TCF7/LEF1. In addition, enhanced AF1q expression promotes breast cancer cell proliferation, migration, mammosphere formation, and chemo-resistance. In xenograft models, enforced AF1q expression in breast cancer cells also promotes liver metastasis and lung colonization. In a cohort of 63 breast cancer patients, higher percentages of AF1q-positive cancer cells in primary sites were associated with significantly poorer overall survival (OS), disease-free survival (DFS), and brain metastasis-free survival (b-MFS). Using paired primary/metastatic samples from the same patients, we demonstrate that AF1q-positive breast cancer cells become dynamically dominant in the metastatic sites compared to the primary sites. Our findings indicate that breast cancer cells with a hyperactive AF1q/TCF7/CD44 regulatory axis in the primary sites may represent “metastatic founder cells” which have invasive properties. PMID:26079538

  19. LNA aptamer based multi-modal, Fe3O4-saturated lactoferrin (Fe3O4-bLf) nanocarriers for triple positive (EpCAM, CD133, CD44) colon tumor targeting and NIR, MRI and CT imaging.

    PubMed

    Roy, Kislay; Kanwar, Rupinder K; Kanwar, Jagat R

    2015-12-01

    This is the first ever attempt to combine anti-cancer therapeutic effects of emerging anticancer biodrug bovine lactoferrin (bLf), and multimodal imaging efficacy of Fe3O4 nanoparticles (NPs) together, as a saturated Fe3O4-bLf. For cancer stem cell specific uptake of nanocapsules/nanocarriers (NCs), Fe3O4-bLf was encapsulated in alginate enclosed chitosan coated calcium phosphate (AEC-CP) NCs targeted (Tar) with locked nucleic acid (LNA) modified aptamers against epithelial cell adhesion molecule (EpCAM) and nucleolin markers. The nanoformulation was fed orally to mice injected with triple positive (EpCAM, CD133, CD44) sorted colon cancer stem cells in the xenograft cancer stem cell mice model. The complete regression of tumor was observed in 70% of mice fed on non-targeted (NT) NCs, with 30% mice showing tumor recurrence after 30 days, while only 10% mice fed with Tar NCs showed tumor recurrence indicating a significantly higher survival rate. From tumor tissue analyses of 35 apoptotic markers, 55 angiogenesis markers, 40 cytokines, 15 stem cell markers and gene expression studies of important signaling molecules, it was revealed that the anti-cancer mechanism of Fe3O4-bLf was intervened through TRAIL, Fas, Fas-associated protein with death domain (FADD) mediated phosphorylation of p53, to induce activation of second mitochondria-derived activator of caspases (SMAC)/DIABLO (inhibiting survivin) and mitochondrial depolarization leading to release of cytochrome C. Induction of apoptosis was observed by inhibition of the Akt pathway and activation of cytokines released from monocytes/macrophages and dendritic cells (interleukin (IL) 27, keratinocyte chemoattractant (KC)). On the other hand, the recurrence of tumor in AEC-CP-Fe3O4-bLf NCs fed mice mainly occurred due to activation of alternative pathways such as mitogen-activated protein kinases (MAPK)/extracellular signal-regulated kinases (ERK) and Wnt signaling leading to an increase in expression of survivin

  20. Nephrin phosphorylation regulates podocyte adhesion through the PINCH-1-ILK-α-parvin complex

    PubMed Central

    Zha, Dongqing; Chen, Cheng; Liang, Wei; Chen, Xinghua; Ma, Tean; Yang, Hongxia; van Goor, Harry; Ding, Guohua

    2013-01-01

    Nephrin, a structural molecule, is also a signaling molecule after phosphorylation. Inhibition of nephrin phosphorylation is correlated with podocyte injury. The PINCH-1-ILK-α-parvin (PIP) complex plays a crucial role in cell adhesion and cytoskeleton formation. We hypothesized that nephrin phosphorylation influenced cytoskeleton and cell adhesion in podocytes by regulating the PIP complex. The nephrin phosphorylation, PIP complex formation, and F-actin in Wistar rats intraperitoneally injected with puromycin aminonucleoside were gradually decreased but increased with time, coinciding with the recovery from glomerular/podocyte injury and proteinuria. In cultured podocytes, PIP complex knockdown resulted in cytoskeleton reorganization and decreased cell adhesion and spreading. Nephrin and its phosphorylation were unaffected after PIP complex knockdown. Furthermore, inhibition of nephrin phosphorylation suppressed PIP complex expression, disorganized podocyte cytoskeleton, and decreased cell adhesion and spreading. These findings indicate that alterations in nephrin phosphorylation disorganize podocyte cytoskeleton and decrease cell adhesion through a PIP complex-dependent mechanism. [BMB Reports 2013; 46(4): 230-235] PMID:23615266

  1. A focal adhesion protein-based mechanochemical checkpoint regulates cleft progression during branching morphogenesis

    PubMed Central

    Daley, William P.; Kohn, Joshua M.; Larsen, Melinda

    2011-01-01

    Cleft formation is the initial step of branching morphogenesis in many organs. We previously demonstrated that ROCK 1 regulates a non-muscle myosin II-dependent mechanochemical checkpoint to transition initiated clefts to progressing clefts in developing submandibular salivary glands. Here, we report that ROCK-mediated integrin activation and subsequent formation of focal adhesion complexes comprise this mechanochemical checkpoint. Inhibition of ROCK1 and non-muscle myosin II activity decreased integrin β1 activation in the cleft region and interfered with localization and activation of focal adhesion complex proteins, such as focal adhesion kinase (FAK). Inhibition of FAK activity also prevented cleft progression, by disrupting recruitment of the focal adhesion proteins talin and vinculin and subsequent fibronectin assembly in the cleft region while decreasing ERK1/2 activation. These results demonstrate that inside-out integrin signaling leading to a localized recruitment of active FAK-containing focal adhesion protein complexes generates a mechanochemical checkpoint that facilitates progression of branching morphogenesis. PMID:22016182

  2. Immunoselection of breast and ovarian cancer cells with trastuzumab and natural killer cells: selective escape of CD44high/CD24low/HER2low breast cancer stem cells.

    PubMed

    Reim, Florian; Dombrowski, Yvonne; Ritter, Cathrin; Buttmann, Mathias; Häusler, Sebastian; Ossadnik, Monika; Krockenberger, Mathias; Beier, Dagmar; Beier, Christoph P; Dietl, Johannes; Becker, Jürgen C; Hönig, Arnd; Wischhusen, Jörg

    2009-10-15

    Although trastuzumab (Herceptin) has substantially improved the overall survival of patients with mammary carcinomas, even initially well-responding tumors often become resistant. Because natural killer (NK) cell-mediated antibody-dependent cell-mediated cytotoxicity (ADCC) is thought to contribute to the therapeutic effects of trastuzumab, we have established a cell culture system to select for ADCC-resistant SK-OV-3 ovarian cancer and MCF7 mammary carcinoma cells. Ovarian cancer cells down-regulated HER2 expression, resulting in a more resistant phenotype. MCF7 breast cancer cells, however, failed to develop resistance in vitro. Instead, treatment with trastuzumab and polyclonal NK cells resulted in the preferential survival of individual sphere-forming cells that displayed a CD44(high)CD24(low) "cancer stem cell-like" phenotype and expressed significantly less HER2 compared with non-stem cells. Likewise, the CD44(high)CD24(low) population was also found to be more immunoresistant in SK-BR3, MDA-MB231, and BT474 breast cancer cell lines. When immunoselected MCF7 cells were then re-expanded, they mostly lost the observed phenotype to regenerate a tumor cell culture that displayed the initial HER2 surface expression and ADCC-susceptibility, but was enriched in CD44(high)CD24(low) cancer stem cells. This translated into increased clonogenicity in vitro and tumorigenicity in vivo. Thus, we provide evidence that the induction of ADCC by trastuzumab and NK cells may spare the actual tumor-initiating cells, which could explain clinical relapse and progress. Moreover, our observation that the "relapsed" in vitro cultures show practically identical HER2 surface expression and susceptibility toward ADCC suggests that the administration of trastuzumab beyond relapse might be considered, especially when combined with an immune-stimulatory treatment that targets the escape variants. PMID:19826050

  3. Targeted disruption of CD44 in MDAY-D2 lymphosarcoma cells has no effect on subcutaneous growth or metastatic capacity

    PubMed Central

    1995-01-01

    CD44 splice variants have been shown to be involved in metastasis of carcinomas. In addition, the standard form of CD44 has been implicated in metastasis, particularly of melanomas and lymphomas. To investigate this, we have generated a CD44-negative mutant of the highly metastatic murine MDAY-D2 lymphosarcoma. The two CD44 alleles of this diploid cell line were sequentially disrupted by homologous recombination, using isogenic CD44 genomic constructs interrupted by a neomycin or hygromycin resistance-conferring gene. The resulting double knockout (DKO) cells had completely lost the capacity to bind to immobilized hyaluronic acid, but did not differ from MDAY-D2 cells in integrin expression or in vitro growth. Subcutaneous (s.c.) growth potential and metastatic capacity of MDAY-D2 and DKO cells were assessed by s.c. and i.v. injection of the lowest cell dose (10(3) or 10(4), respectively) that gave rise to tumor formation by MDAY-D2 cells in approximately 100% of the mice. Quite unexpectedly, we observed no difference at all in either s.c. growth rate or local invasion into surrounding tissues between MDAY-D2 cells and the CD44-negative DKO cells. Also hematogenous metastasis formation upon i.v. injection was similar: both parental and DKO cells metastasized extensively to the spleen, liver, and bone marrow. We conclude that, at least for these MDAY-D2 lymphosarcoma cells, the standard form of CD44 is dispensable for tumor growth and metastasis. Our results show that targeted disruption of genes in tumor cells is a feasible approach to study their role in tumorigenesis and metastasis. PMID:8557751

  4. The role of focal adhesion kinase in the regulation of cellular mechanical properties

    NASA Astrophysics Data System (ADS)

    Mierke, Claudia Tanja

    2013-12-01

    The regulation of mechanical properties is necessary for cell invasion into connective tissue or intra- and extravasation through the endothelium of blood or lymph vessels. Cell invasion is important for the regulation of many healthy processes such as immune response reactions and wound healing. In addition, cell invasion plays a role in disease-related processes such as tumor metastasis and autoimmune responses. Until now the role of focal adhesion kinase (FAK) in regulating mechanical properties of cells and its impact on cell invasion efficiency is still not well known. Thus, this review focuses on mechanical properties regulated by FAK in comparison to the mechano-regulating protein vinculin. Moreover, it points out the connection between cancer cell invasion and metastasis and FAK by showing that FAK regulates cellular mechanical properties required for cellular motility. Furthermore, it sheds light on the indirect interaction of FAK with vinculin by binding to paxillin, which then impairs the binding of paxillin to vinculin. In addition, this review emphasizes whether FAK fulfills regulatory functions similar to vinculin. In particular, it discusses the differences and the similarities between FAK and vinculin in regulating the biomechanical properties of cells. Finally, this paper highlights that both focal adhesion proteins, vinculin and FAK, synergize their functions to regulate the mechanical properties of cells such as stiffness and contractile forces. Subsequently, these mechanical properties determine cellular invasiveness into tissues and provide a source sink for future drug developments to inhibit excessive cell invasion and hence, metastases formation.

  5. Phosphoinositide lipid phosphatase SHIP1 and PTEN coordinate to regulate cell migration and adhesion

    PubMed Central

    Mondal, Subhanjan; Subramanian, Kulandayan K.; Sakai, Jiro; Bajrami, Besnik; Luo, Hongbo R.

    2012-01-01

    The second messenger phosphatidylinositol(3,4,5)P3 (PtdIns(3,4,5)P3) is formed by stimulation of various receptors, including G protein–coupled receptors and integrins. The lipid phosphatases PTEN and SHIP1 are critical in regulating the level of PtdIns(3,4,5)P3 during chemotaxis. Observations that loss of PTEN had minor and loss of SHIP1 resulted in a severe chemotaxis defect in neutrophils led to the belief that SHIP1 rather than PTEN acts as a predominant phospholipid phosphatase in establishing a PtdIns(3,4,5)P3 compass. In this study, we show that SHIP1 regulates PtdIns(3,4,5)P3 production in response to cell adhesion and plays a limited role when cells are in suspension. SHIP1−/− neutrophils lose their polarity upon cell adhesion and are extremely adherent, which impairs chemotaxis. However, chemo­taxis can be restored by reducing adhesion. Loss of SHIP1 elevates Akt activation following cell adhesion due to increased PtdIns(3,4,5)P3 production. From our observations, we conclude that SHIP1 prevents formation of top-down PtdIns(3,4,5)P3 polarity to facilitate proper cell attachment and detachment during chemotaxis. PMID:22323291

  6. Pyk2 Controls Integrin-Dependent CTL Migration through Regulation of De-Adhesion.

    PubMed

    Cheung, Samuel M S; Ostergaard, Hanne L

    2016-09-01

    Protein tyrosine kinase 2 (Pyk2) is required for T cell adhesion to ICAM-1; however, the mechanism by which it regulates adhesion remains unexplored. Pyk2 function in murine CTL clones and activated ex vivo CD8(+) T cells was disrupted by pharmacological inhibition, knockdown of expression with small interfering RNA, or expression of the dominant-negative C-terminal domain. We found that Pyk2 is not absolutely required for adhesion of CTL to ICAM-1, but rather delays the initial adhesion. Disruption of Pyk2 function caused cells to display an unusual elongated appearance after 1 h on ICAM-1, consistent with abnormally strong adhesion. Furthermore, the random mobility of CTL on ICAM-1 was severely compromised using all three methods of disrupting Pyk2 function. Live-cell imaging studies revealed that the decreased migration is the result of a defect in the detachment from ICAM-1 at the trailing edge when Pyk2 function is inhibited. Examination of Pyk2 tyrosine phosphorylation in normal polarized cells demonstrated that Pyk2 phosphorylated at Y579 and Y580 preferentially localizes to the leading edge, whereas Y881-phosphorylated Pyk2 is enriched at the trailing edge, suggesting that the tyrosine phosphorylation of Pyk2 is spatially regulated in migrating CTL. Additionally, inhibition of Pyk2 caused cells to form multiple LFA-1-rich tails at the trailing edge, most likely resulting from a defect in LFA-1 release required for forward movement. Our results show that Pyk2 contributes to CTL migration by regulating detachment of CTL at the trailing edge, which could explain why Pyk2 is important for chemotactic and migratory responses. PMID:27456486

  7. Moesin Interacts with the Cytoplasmic Region of Intercellular Adhesion Molecule-3 and Is Redistributed to the Uropod of T Lymphocytes during Cell Polarization

    PubMed Central

    Serrador, Juan M.; Alonso-Lebrero, José L.; Pozo, Miguel A. del; Furthmayr, Heinz; Schwartz-Albiez, Reinhard; Calvo, Javier; Lozano, Francisco; Sánchez-Madrid, Francisco

    1997-01-01

    During activation, T lymphocytes become motile cells, switching from a spherical to a polarized shape. Chemokines and other chemotactic cytokines induce lymphocyte polarization with the formation of a uropod in the rear pole, where the adhesion receptors intercellular adhesion molecule-1 (ICAM-1), ICAM-3, and CD44 redistribute. We have investigated membrane–cytoskeleton interactions that play a key role in the redistribution of adhesion receptors to the uropod. Immunofluorescence analysis showed that the ERM proteins radixin and moesin localized to the uropod of human T lymphoblasts treated with the chemokine RANTES (regulated on activation, normal T cell expressed, and secreted), a polarization-inducing agent; radixin colocalized with arrays of myosin II at the neck of the uropods, whereas moesin decorated the most distal part of the uropod and colocalized with ICAM-1, ICAM-3, and CD44 molecules. Two other cytoskeletal proteins, β-actin and α-tubulin, clustered at the cell leading edge and uropod, respectively, of polarized lymphocytes. Biochemical analysis showed that moesin coimmunoprecipitates with ICAM-3 in T lymphoblasts stimulated with either RANTES or the polarization- inducing anti–ICAM-3 HP2/19 mAb, as well as in the constitutively polarized T cell line HSB-2. In addition, moesin is associated with CD44, but not with ICAM-1, in polarized T lymphocytes. A correlation between the degree of moesin–ICAM-3 interaction and cell polarization was found as determined by immunofluorescence and immunoprecipitation analysis done in parallel. The moesin–ICAM-3 interaction was specifically mediated by the cytoplasmic domain of ICAM-3 as revealed by precipitation of moesin with a GST fusion protein containing the ICAM-3 cytoplasmic tail from metabolically labeled Jurkat T cell lysates. The interaction of moesin with ICAM-3 was greatly diminished when RANTES-stimulated T lymphoblasts were pretreated with the myosin-disrupting drug butanedione monoxime, which

  8. Hypoxia facilitates tumour cell detachment by reducing expression of surface adhesion molecules and adhesion to extracellular matrices without loss of cell viability.

    PubMed Central

    Hasan, N. M.; Adams, G. E.; Joiner, M. C.; Marshall, J. F.; Hart, I. R.

    1998-01-01

    The effects of acute hypoxia on integrin expression and adhesion to extracellular matrix proteins were investigated in two human melanoma cell lines, HMB-2 and DX3, and a human adenocarcinoma cell line, HT29. Exposure to hypoxia caused a significant down-regulation of cell surface integrins and an associated decrease in cell adhesion. Loss of cell adhesion and integrin expression were transient and levels returned to normal within 24 h of reoxygenation. Other cell adhesion molecules, such as CD44 and N-CAM, were also down-regulated after exposure of cells to hypoxia. Acute exposure to hypoxia of cells at confluence caused rapid cell detachment. Cell detachment preceded loss of viability. Detached HMB-2 and DX3 cells completely recovered upon reoxygenation, and floating cells re-attached and continued to grow irrespective of whether they were left in the original glass dishes or transferred to new culture vessels, while detached HT29 cells partly recovered upon reoxygenation. Cell detachment after decreased adhesion appears to be a stress response, which may be a factor enabling malignant cells to escape hypoxia in vivo, with the potential to form new foci of tumour growth. PMID:9667649

  9. CD44-Targeted Hyaluronic Acid-Coated Redox-Responsive Hyperbranched Poly(amido amine)/Plasmid DNA Ternary Nanoassemblies for Efficient Gene Delivery.

    PubMed

    Gu, Jijin; Chen, Xinyi; Ren, Xiaoqing; Zhang, Xiulei; Fang, Xiaoling; Sha, Xianyi

    2016-07-20

    Hyaluronic acid (HA), which can specifically bind to CD44 receptor, is a specific ligand for targeting to CD44-overexpressing cancer cells. The current study aimed to develop ternary nanoassemblies based on HA-coating for targeted gene delivery to CD44-positive tumors. A novel reducible hyperbranched poly(amido amine) (RHB) was assembled with plasmid DNA (pDNA) to form RHB/pDNA nanoassemblies. HA/RHB/pDNA nanoassemblies were fabricated by coating HA on the surface of the RHB/pDNA nanoassembly core through electrostatic interaction. After optimization, HA/RHB/pDNA nanoassemblies were spherical, core-shell nanoparticles with nanosize (187.6 ± 11.4 nm) and negative charge (-9.1 ± 0.3 mV). The ternary nanoassemblies could efficiently protect the condensed pDNA from enzymatic degradation by DNase I, and HA could significantly improve the stability of nanoassemblies in the sodium heparin solution or serum in vitro. As expected, HA significantly decreased the cytotoxicity of RHB/pDNA nanoassemblies due to the negative surface charges. Moreover, it revealed that HA/RHB/pDNA nanoassemblies showed higher transfection activity than RHB/pDNA nanoassemblies in B16F10 cells, especially in the presence of serum in vitro. Because of the active recognition between HA and CD44 receptor, there was significantly different transfection efficiency between B16F10 (CD44+) and NIH3T3 (CD44-) cells after treatment with HA/RHB/pDNA nanoassemblies. In addition, the cellular targeting and transfection activity of HA/RHB/pDNA nanoassemblies were further evaluated in vivo. The results indicated that the interaction between HA and CD44 receptor dramatically improved the accumulation of HA/RHB/pDNA nanoassemblies in CD44-positive tumor, leading to higher gene expression than RHB/pDNA nanoassemblies. Therefore, HA/RHB/pDNA ternary nanoassemblies may be a potential gene vector for delivery of therapeutic genes to treat CD44-overexpressing tumors in vivo. PMID:27311558

  10. Osteocyte apoptosis regulates osteoclast precursor adhesion via osteocytic IL-6 secretion and endothelial ICAM-1 expression.

    PubMed

    Cheung, Wing-Yee; Simmons, Craig A; You, Lidan

    2012-01-01

    Osteocyte apoptosis precedes osteoclast resorption, and may act as a critical signal to trigger bone remodeling. While osteoclast precursors are known to travel via the circulation, the specific mechanisms by which they accumulate at remodeling sites are unclear. We hypothesized that osteocyte apoptosis mediates osteoclast precursor adhesion to vascular endothelium by regulating osteocytic secretion of IL-6 and soluble IL-6 receptor (sIL-6R) to promote endothelial ICAM-1 expression. We found that conditioned media from TNF-α-induced apoptotic MLO-Y4 osteocytes promoted RAW264.7 osteoclast precursor adhesion onto D4T endothelial cells (P<0.05). Blocking osteocyte apoptosis with a pan-caspase inhibitor (ZVAD-FMK) reduced osteoclast precursor adhesion to baseline levels (P<0.001). Endothelial cells treated with apoptotic osteocyte conditioned media had elevated surface expression of ICAM-1 (P<0.05), and blocking ICAM-1 abolished apoptosis-induced osteoclast precursor adhesion. Apoptotic osteocyte conditioned media contained more IL-6 (P<0.05) and sIL-6R (P<0.05) than non-apoptotic osteocyte conditioned media. When added exogenously, both IL-6 and sIL-6R were required for endothelial activation, and blocking IL-6 reduced apoptosis-induced osteoclast precursor adhesion to baseline levels (P<0.05). Therefore, we conclude that osteocyte apoptosis can promote osteoclast precursor adhesion to endothelial cells via ICAM-1; this is likely through increased osteocytic IL-6 and sIL-6R secretion, both of which are indispensible to endothelial activation. PMID:21986000

  11. Efficient CD44-targeted magnetic resonance imaging (MRI) of breast cancer cells using hyaluronic acid (HA)-modified MnFe2O4 nanocrystals

    PubMed Central

    2013-01-01

    Targeted molecular imaging with hyaluronic acid (HA) has been highlighted in the diagnosis and treatment of CD44-overexpressing cancer. CD44, a receptor for HA, is closely related to the growth of cancer including proliferation, metastasis, invasion, and angiogenesis. For the efficient detection of CD44, we fabricated a few kinds of HA-modified MnFe2O4 nanocrystals (MNCs) to serve as specific magnetic resonance (MR) contrast agents (HA-MRCAs) and compared physicochemical properties, biocompatibility, and the CD44 targeting efficiency. Hydrophobic MNCs were efficiently phase-transferred using aminated polysorbate 80 (P80) synthesized by introducing spermine molecules on the hydroxyl groups of P80. Subsequently, a few kinds of HA-MRCAs were fabricated, conjugating different ratios of HA on the equal amount of phase-transferred MNCs. The optimized conjugation ratio of HA against magnetic content was identified to exhibit not only effective CD44 finding ability but also high cell viability through in vitro experiments. The results of this study demonstrate that the suggested HA-MRCA shows strong potential to be used for accurate tumor diagnosis. PMID:23547716

  12. Efficient CD44-targeted magnetic resonance imaging (MRI) of breast cancer cells using hyaluronic acid (HA)-modified MnFe2O4 nanocrystals

    NASA Astrophysics Data System (ADS)

    Lee, Taeksu; Lim, Eun-Kyung; Lee, Jaemin; Kang, Byunghoon; Choi, Jihye; Park, Hyo Seon; Suh, Jin-Suck; Huh, Yong-Min; Haam, Seungjoo

    2013-04-01

    Targeted molecular imaging with hyaluronic acid (HA) has been highlighted in the diagnosis and treatment of CD44-overexpressing cancer. CD44, a receptor for HA, is closely related to the growth of cancer including proliferation, metastasis, invasion, and angiogenesis. For the efficient detection of CD44, we fabricated a few kinds of HA-modified MnFe2O4 nanocrystals (MNCs) to serve as specific magnetic resonance (MR) contrast agents (HA-MRCAs) and compared physicochemical properties, biocompatibility, and the CD44 targeting efficiency. Hydrophobic MNCs were efficiently phase-transferred using aminated polysorbate 80 (P80) synthesized by introducing spermine molecules on the hydroxyl groups of P80. Subsequently, a few kinds of HA-MRCAs were fabricated, conjugating different ratios of HA on the equal amount of phase-transferred MNCs. The optimized conjugation ratio of HA against magnetic content was identified to exhibit not only effective CD44 finding ability but also high cell viability through in vitro experiments. The results of this study demonstrate that the suggested HA-MRCA shows strong potential to be used for accurate tumor diagnosis.

  13. The Ret receptor regulates sensory neuron dendrite growth and integrin mediated adhesion

    PubMed Central

    Soba, Peter; Han, Chun; Zheng, Yi; Perea, Daniel; Miguel-Aliaga, Irene; Jan, Lily Yeh; Jan, Yuh Nung

    2015-01-01

    Neurons develop highly stereotyped receptive fields by coordinated growth of their dendrites. Although cell surface cues play a major role in this process, few dendrite specific signals have been identified to date. We conducted an in vivo RNAi screen in Drosophila class IV dendritic arborization (C4da) neurons and identified the conserved Ret receptor, known to play a role in axon guidance, as an important regulator of dendrite development. The loss of Ret results in severe dendrite defects due to loss of extracellular matrix adhesion, thus impairing growth within a 2D plane. We provide evidence that Ret interacts with integrins to regulate dendrite adhesion via rac1. In addition, Ret is required for dendrite stability and normal F-actin distribution suggesting it has an essential role in dendrite maintenance. We propose novel functions for Ret as a regulator in dendrite patterning and adhesion distinct from its role in axon guidance. DOI: http://dx.doi.org/10.7554/eLife.05491.001 PMID:25764303

  14. Synaptic adhesion molecule IgSF11 regulates synaptic transmission and plasticity

    PubMed Central

    Shin, Hyewon; van Riesen, Christoph; Whitcomb, Daniel; Warburton, Julia M.; Jo, Jihoon; Kim, Doyoun; Kim, Sun Gyun; Um, Seung Min; Kwon, Seok-kyu; Kim, Myoung-Hwan; Roh, Junyeop Daniel; Woo, Jooyeon; Jun, Heejung; Lee, Dongmin; Mah, Won; Kim, Hyun; Kaang, Bong-Kiun; Cho, Kwangwook; Rhee, Jeong-Seop; Choquet, Daniel; Kim, Eunjoon

    2016-01-01

    Summary Synaptic adhesion molecules regulate synapse development and plasticity through mechanisms including trans-synaptic adhesion and recruitment of diverse synaptic proteins. We report here that the immunoglobulin superfamily member 11 (IgSF11), a homophilic adhesion molecule preferentially expressed in the brain, is a novel and dual-binding partner of the postsynaptic scaffolding protein PSD-95 and AMPAR glutamate receptors (AMPARs). IgSF11 requires PSD-95 binding for its excitatory synaptic localization. In addition, IgSF11 stabilizes synaptic AMPARs, as shown by IgSF11 knockdown-induced suppression of AMPAR-mediated synaptic transmission and increased surface mobility of AMPARs, measured by high-throughput, single-molecule tracking. IgSF11 deletion in mice leads to suppression of AMPAR-mediated synaptic transmission in the dentate gyrus and long-term potentiation in the CA1 region of the hippocampus. IgSF11 does not regulate the functional characteristics of AMPARs, including desensitization, deactivation, or recovery. These results suggest that IgSF11 regulates excitatory synaptic transmission and plasticity through its tripartite interactions with PSD-95 and AMPARs. PMID:26595655

  15. Initial steps of Shigella infection depend on the cholesterol/sphingolipid raft-mediated CD44-IpaB interaction.

    PubMed

    Lafont, Frank; Tran Van Nhieu, Guy; Hanada, Kentaro; Sansonetti, Philippe; van der Goot, F Gisou

    2002-09-01

    Shigellosis is an acute inflammatory bowel disease caused by the enteroinvasive bacterium SHIGELLA: Upon host cell-Shigella interaction, major host cell signalling responses are activated. Deciphering the initial molecular events is crucial to understanding the infectious process. We identified a molecular complex involving proteins of both the host, CD44 the hyaluronan receptor, and Shigella, the invasin IpaB, which partitions during infection within specialized membrane microdomains enriched in cholesterol and sphingolipids, called rafts. We also document accumulation of cholesterol and raft-associated proteins at Shigella entry foci. Moreover, we report that Shigella entry is impaired after cholesterol depletion using methyl-beta-cyclodextrin. Finally, we find that Shigella is less invasive in sphingosid-based lipid-deficient cell lines, demonstrating the involvement of sphingolipids. Our results show that rafts are implicated in Shigella binding and entry, suggesting that raft-associated molecular machineries are engaged in mediating the cell signalling response required for the invasion process. PMID:12198147

  16. Increased serum levels of soluble CD44-isoform v5 in rheumatic diseases are restricted to seropositive rheumatoid arthritis.

    PubMed

    Haberhauer, G; Kittl, E M; Skoumal, M; Hübl, W; Wagner, E; Bayer, P M; Bauer, K; Dunky, A

    1997-01-01

    Serum levels of sCD44v5 were measured in 134 patients with definite inflammatory rheumatic diseases (IRD) using a sandwich type ELISA. 94 patients suffered from erosive IgM-rheumatoid factor positive rheumatoid arthritis (RA+), 20 with undifferentiated seronegative polyarthritis, 12 with osteoarthropathia psoriatica and psoriasis vulgaris, 3 with systemic lupus erythematosus, 3 with scleroderma and 2 with reactive arthritis. Elevated serum levels (> 58 ng/ml to 221 ng/ml; median: 93 ng/ml) were only detected in 54/94 (57%) patients with RA+, but not in other IRD. They correlated with advanced stages of disease (Steinbrocker stages III + IV; p < 0.05), elevated CRP-levels (p < 0.01) and higher measurements of IgM rheumatoid factor. PMID:9150806

  17. Regulation of promyogenic signal transduction by cell-cell contact and adhesion

    SciTech Connect

    Krauss, Robert S.

    2010-11-01

    Skeletal myoblast differentiation involves acquisition of the muscle-specific transcriptional program and morphological changes, including fusion into multinucleated myofibers. Differentiation is regulated by extracellular signaling cues, including cell-cell contact and adhesion. Cadherin and Ig adhesion receptors have been implicated in distinct but overlapping stages of myogenesis. N-cadherin signals through the Ig receptor Cdo to activate p38 MAP kinase, while the Ig receptor neogenin signals to activate FAK; both processes promote muscle-specific gene expression and myoblast fusion. M-cadherin activates Rac1 to enhance fusion. Specific Ig receptors (Kirre and Sns) are essential for myoblast fusion in Drosophila, also signaling through Rac, and vertebrate orthologs of Kirre and Sns have partially conserved function. Mice lacking specific cytoplasmic signaling factors activated by multiple receptors (e.g., Rac1) have strong muscle phenotypes in vivo. In contrast, mice lacking individual adhesion receptors that lie upstream of these factors have modest phenotypes. Redundancy among receptors may account for this. Many of the mammalian Ig receptors and cadherins associate with each other, and multivalent interactions within these complexes may require removal of multiple components to reveal dramatic defects in vivo. Nevertheless, it is possible that the murine adhesion receptors rate-limiting in vivo have not yet been identified or fully assessed.

  18. Regulation of promyogenic signal transduction by cell-cell contact and adhesion

    PubMed Central

    Krauss, Robert S.

    2010-01-01

    Skeletal myoblast differentiation involves acquisition of the muscle-specific transcriptional program and morphological changes, including fusion into multinucleated myofibers. Differentiation is regulated by extracellular signaling cues, including cell-cell contact and adhesion. Cadherin and Ig adhesion receptors have been implicated in distinct but overlapping stages of myogenesis. N-cadherin signals through the Ig receptor Cdo to activate p38 MAP kinase, while the Ig receptor neogenin signals to activate FAK; both processes promote muscle-specific gene expression and myoblast fusion. M-cadherin activates Rac1 to enhance fusion. Specific Ig receptors (Kirre, Sns) are essential for myoblast fusion in Drosophila, also signaling through Rac, and vertebrate orthologs of Kirre and Sns have partially conserved function. Mice lacking specific cytoplasmic signaling factors activated by multiple receptors (e.g., Rac1) have strong muscle phenotypes in vivo. In contrast, mice lacking individual adhesion receptors that lie upstream of these factors have modest phenotypes. Redundancy among receptors may account for this. Many of the mammalian Ig receptors and cadherins associate with each other, and multivalent interactions within these complexes may require removal of multiple components to reveal dramatic defects in vivo. Nevertheless, it is possible that the murine adhesion receptors rate-limiting in vivo have not yet been identified or fully assessed. PMID:20471976

  19. Molecular Basis of Kindlin-2 Binding to Integrin-linked Kinase Pseudokinase for Regulating Cell Adhesion*

    PubMed Central

    Fukuda, Koichi; Bledzka, Kamila; Yang, Jun; Perera, H. Dhanuja; Plow, Edward F.; Qin, Jun

    2014-01-01

    Integrin-linked kinase (ILK) is a distinct intracellular adaptor essential for integrin-mediated cell-extracellular matrix adhesion, cell spreading, and migration. Acting as a major docking platform in focal adhesions, ILK engages many proteins to dynamically link integrins with the cytoskeleton, but the underlying mechanism remains elusive. Here, we have characterized the interaction of ILK with kindlin-2, a key regulator for integrin bidirectional signaling. We show that human kindlin-2 binds to human ILK with high affinity. Using systematic mapping approaches, we have identified a major ILK binding site involving a 20-residue fragment (residues 339–358) in kindlin-2. NMR-based analysis reveals a helical conformation of this fragment that utilizes its leucine-rich surface to recognize the ILK pseudokinase domain in a mode that is distinct from another ILK pseudokinase domain binding protein, α-parvin. Structure-based mutational experiments further demonstrate that the kindlin-2 binding to ILK is crucial for the kindlin-2 localization to focal adhesions and cell spreading (integrin outside-in signaling) but dispensable for the kindlin-2-mediated integrin activation (integrin inside-out signaling). These data define a specific mode of the kindlin-2/ILK interaction with mechanistic implications as to how it spatiotemporally mediates integrin signaling and cell adhesion. PMID:25160619

  20. The Focal Adhesion-Localized CdGAP Regulates Matrix Rigidity Sensing and Durotaxis

    PubMed Central

    Wormer, Duncan B.; Davis, Kevin A.; Henderson, James H.; Turner, Christopher E.

    2014-01-01

    Motile cells are capable of sensing the stiffness of the surrounding extracellular matrix through integrin-mediated focal adhesions and migrate towards regions of higher rigidity in a process known as durotaxis. Durotaxis plays an important role in normal development and disease progression, including tumor invasion and metastasis. However, the signaling mechanisms underlying focal adhesion-mediated rigidity sensing and durotaxis are poorly understood. Utilizing matrix-coated polydimethylsiloxane gels to manipulate substrate compliance, we show that cdGAP, an adhesion-localized Rac1 and Cdc42 specific GTPase activating protein, is necessary for U2OS osteosarcoma cells to coordinate cell shape changes and migration as a function of extracellular matrix stiffness. CdGAP regulated rigidity-dependent motility by controlling membrane protrusion and adhesion dynamics, as well as by modulating Rac1 activity. CdGAP was also found to be necessary for U2OS cell durotaxis. Taken together, these data identify cdGAP as an important component of an integrin-mediated signaling pathway that senses and responds to mechanical cues in the extracellular matrix in order to coordinate directed cell motility. PMID:24632816

  1. Adhesion energy can regulate vesicle fusion and stabilize partially fused states

    PubMed Central

    Long, Rong; Hui, Chung-Yuen; Jagota, Anand; Bykhovskaia, Maria

    2012-01-01

    Release of neurotransmitters from nerve terminals occurs by fusion of synaptic vesicles with the plasma membrane, and this process is highly regulated. Although major molecular components that control docking and fusion of vesicles to the synaptic membrane have been identified, the detailed mechanics of this process is not yet understood. We have developed a mathematical model that predicts how adhesion forces imposed by docking and fusion molecular machinery would affect the fusion process. We have computed the membrane stress that is produced by adhesion-driven vesicle bending and find that it is compressive. Further, our computations of the membrane curvature predict that strong adhesion can create a metastable state with a partially opened pore that would correspond to the ‘kiss and run’ release mode. Our model predicts that the larger the vesicle size, the more likely the metastable state with a transiently opened pore. These results contribute to understanding the mechanics of the fusion process, including possible clamping of the fusion by increasing molecular adhesion, and a balance between ‘kiss and run’ and full collapse fusion modes. PMID:22258550

  2. Targeting Tumor Cells with Anti-CD44 Antibody Triggers Macrophage-Mediated Immune Modulatory Effects in a Cancer Xenograft Model

    PubMed Central

    Maisel, Daniela; Birzele, Fabian; Voss, Edgar; Nopora, Adam; Bader, Sabine; Friess, Thomas; Goller, Bernhard; Laifenfeld, Daphna; Weigand, Stefan; Runza, Valeria

    2016-01-01

    CD44, a transmembrane receptor reported to be involved in various cellular functions, is overexpressed in several cancer types and supposed to be involved in the initiation, progression and prognosis of these cancers. Since the sequence of events following the blockage of the CD44-HA interaction has not yet been studied in detail, we profiled xenograft tumors by RNA Sequencing to elucidate the mode of action of the anti-CD44 antibody RG7356. Analysis of tumor and host gene-expression profiles led us to the hypothesis that treatment with RG7356 antibody leads to an activation of the immune system. Using cytokine measurements we further show that this activation involves the secretion of chemo-attractants necessary for the recruitment of immune cells (i.e. macrophages) to the tumor site. We finally provide evidence for antibody-dependent cellular phagocytosis (ADCP) of the malignant cells by macrophages. PMID:27463372

  3. CD44 targeted chemotherapy for co-eradication of breast cancer stem cells and cancer cells using polymeric nanoparticles of salinomycin and paclitaxel.

    PubMed

    Muntimadugu, Eameema; Kumar, Rajendra; Saladi, Shantikumar; Rafeeqi, Towseef Amin; Khan, Wahid

    2016-07-01

    This combinational therapy is mainly aimed for complete eradication of tumor by killing both cancer cells and cancer stem cells. Salinomycin (SLM) was targeted towards cancer stem cells whereas paclitaxel (PTX) was used to kill cancer cells. Drug loaded poly (lactic-co-glycolic acid) nanoparticles were prepared by emulsion solvent diffusion method using cationic stabilizer. Size of the nanoparticles (below 150nm) was determined by dynamic light scattering technique and transmission electron microscopy. In vitro release study confirmed the sustained release pattern of SLM and PTX from nanoparticles more than a month. Cytotoxicity studies on MCF-7 cells revealed the toxicity potential of nanoparticles over drug solutions. Hyaluronic acid (HA) was coated onto the surface of SLM nanoparticles for targeting CD44 receptors over expressed on cancer stem cells and they showed the highest cytotoxicity with minimum IC50 on breast cancer cells. Synergistic cytotoxic effect was also observed with combination of nanoparticles. Cell uptake studies were carried out using FITC loaded nanoparticles. These particles showed improved cellular uptake over FITC solution and HA coating further enhanced the effect by 1.5 folds. CD44 binding efficiency of nanoparticles was studied by staining MDA-MB-231 cells with anti CD44 human antibody and CD44(+) cells were enumerated using flow cytometry. CD44(+) cell count was drastically decreased when treated with HA coated SLM nanoparticles indicating their efficiency towards cancer stem cells. Combination of HA coated SLM nanoparticles and PTX nanoparticles showed the highest cytotoxicity against CD44(+) cells. Hence combinational therapy using conventional chemotherapeutic drug and cancer stem cell inhibitor could be a promising approach in overcoming cancer recurrence due to resistant cell population. PMID:27045981

  4. Decreased expression of autophagy protein LC3 and stemness (CD44+/CD24-/low) indicate poor prognosis in triple-negative breast cancer.

    PubMed

    Chang, Shu-Jyuan; Ou-Yang, Fu; Tu, Hung-Pin; Lin, Chih-Hung; Huang, Shu-Hung; Kostoro, Joanna; Hou, Ming-Feng; Chai, Chee-Yin; Kwan, Aij-Lie

    2016-02-01

    This study evaluated the prognostic value of expression of autophagy protein light chain 3 (LC3) and the prognostic value of coexpression of LC3 and stemness markers CD44+/CD24-/low in triple-negative breast cancer (TNBC). LC3 and LC3/CD44+/CD24-/low immunophenotypes in tumor tissues were evaluated by immunohistochemistry in 67 TNBC patients. LC3- was expressed in 30 (44.78%) cases. The LC3- phenotype revealed a significant negative association with overall survival in both univariate (P = .0006) and multivariate (P = .0153) analyses. LC3-/CD44+/CD24-/low phenotype was observed in 24 (35.82%) of 67 TNBC patients. According to Kaplan-Meier analysis, prognosis was significantly worse in tumors with LC3-/CD44+/CD24-/low phenotype (P = .0280). Multivariate analysis indicated that LC3-/CD44+/CD24-/low phenotype was a significant independent prognostic indicator of overall survival. These results suggest that LC3 suppresses TNBC in mature tumor cells and cancer stem cells (CSCs). In conclusion, this study suggests that CSCs are linked to progression of autophagy in TNBC. During the progression and development of TNBC, autophagy of CSCs/progenitor cells is low. LC3-/CD44+/CD24-/low immunophenotype indicates a highly aggressive TNBC subgroup associated with a poor prognosis. This study investigated that LC3 deficiency may restrain TNBC in mature tumor cells and CSCs. Therefore, a reasonable inference is that inducing autophagy may be an effective therapeutic strategy in TNBC. PMID:26772398

  5. Focal adhesion kinase regulates expression of thioredoxin-interacting protein (TXNIP) in cancer cells.

    PubMed

    Ho, Baotran; Huang, Grace; Golubovskaya, Vita M

    2014-01-01

    Focal Adhesion Kinase (FAK) plays an important role in cancer cell survival. Previous microarray gene profiling study detected inverse regulation between expression of thioredoxin-interacting protein (TXNIP) and FAK, where down-regulation of FAK by siRNA in MCF-7 cells caused up-regulation of TXNIP mRNA level, and in contrast up-regulation of doxycyclin- induced FAK caused repression of TXNIP. In the present report, we show that overexpression of FAK in MCF-7 cells repressed TXNIP promoter activity. Treatment of MCF-7 cells with 1alpha, 25-dihydroxyvitamin D3 (1,25D) down-regulated endogenous FAK and up-regulated TXNIP protein level, and treatment with 5-FU decreased FAK protein expression and up-regulated TXNIP protein expression in 293 cells. Moreover, silencing of FAK with siRNA increased TXNIP protein expression, while overexpression of FAK inhibited TXNIP protein expression in 293 cells. In addition, treatment of DBTRG glioblastoma cells with FAK inhibitor Y15 increased TXNIP mRNA, decreased cancer cell viability and increased apoptosis. These results for the first time demonstrate FAK-regulated TXNIP expression which is important for apoptotic, survival and oxidative stress signaling pathways in cancer cells. PMID:23387972

  6. Secreted Frizzled-related protein 1 (sFRP1) regulates spermatid adhesion in the testis via dephosphorylation of focal adhesion kinase and the nectin-3 adhesion protein complex

    PubMed Central

    Wong, Elissa W. P.; Lee, Will M.; Cheng, C. Yan

    2013-01-01

    Development of spermatozoa in adult mammalian testis during spermatogenesis involves extensive cell migration and differentiation. Spermatogonia that reside at the basal compartment of the seminiferous epithelium differentiate into more advanced germ cell types that migrate toward the apical compartment until elongated spermatids are released into the tubule lumen during spermiation. Apical ectoplasmic specialization (ES; a testis-specific anchoring junction) is the only cell junction that anchors and maintains the polarity of elongating/elongated spermatids (step 8–19 spermatids) in the epithelium. Little is known regarding the signaling pathways that trigger the disassembly of the apical ES at spermiation. Here, we show that secreted Frizzled-related protein 1 (sFRP1), a putative tumor suppressor gene that is frequently down-regulated in multiple carcinomas, is a crucial regulatory protein for spermiation. The expression of sFRP1 is tightly regulated in adult rat testis to control spermatid adhesion and sperm release at spermiation. Down-regulation of sFRP1 during testicular development was found to coincide with the onset of the first wave of spermiation at approximately age 45 d postpartum, implying that sFRP1 might be correlated with elongated spermatid adhesion conferred by the apical ES before spermiation. Indeed, administration of sFRP1 recombinant protein to the testis in vivo delayed spermiation, which was accompanied by down-regulation of phosphorylated (p)-focal adhesion kinase (FAK)-Tyr397 and retention of nectin-3 adhesion protein at the apical ES. To further investigate the functional relationship between p-FAK-Tyr397 and localization of nectin-3, we overexpressed sFRP1 using lentiviral vectors in the Sertoli-germ cell coculture system. Consistent with the in vivo findings, overexpression of sFRP1 induced down-regulation of p-FAK-Tyr397, leading to a decline in phosphorylation of nectin-3. In summary, this report highlights the critical role of s

  7. Secretagogin affects insulin secretion in pancreatic β-cells by regulating actin dynamics and focal adhesion

    PubMed Central

    Yang, Seo-Yun; Lee, Jae-Jin; Lee, Jin-Hee; Lee, Kyungeun; Oh, Seung Hoon; Lim, Yu-Mi; Lee, Myung-Shik; Lee, Kong-Joo

    2016-01-01

    Secretagogin (SCGN), a Ca2+-binding protein having six EF-hands, is selectively expressed in pancreatic β-cells and neuroendocrine cells. Previous studies suggested that SCGN enhances insulin secretion by functioning as a Ca2+-sensor protein, but the underlying mechanism has not been elucidated. The present study explored the mechanism by which SCGN enhances glucose-induced insulin secretion in NIT-1 insulinoma cells. To determine whether SCGN influences the first or second phase of insulin secretion, we examined how SCGN affects the kinetics of insulin secretion in NIT-1 cells. We found that silencing SCGN suppressed the second phase of insulin secretion induced by glucose and H2O2, but not the first phase induced by KCl stimulation. Recruitment of insulin granules in the second phase of insulin secretion was significantly impaired by knocking down SCGN in NIT-1 cells. In addition, we found that SCGN interacts with the actin cytoskeleton in the plasma membrane and regulates actin remodelling in a glucose-dependent manner. Since actin dynamics are known to regulate focal adhesion, a critical step in the second phase of insulin secretion, we examined the effect of silencing SCGN on focal adhesion molecules, including FAK (focal adhesion kinase) and paxillin, and the cell survival molecules ERK1/2 (extracellular-signal-regulated kinase 1/2) and Akt. We found that glucose- and H2O2-induced activation of FAK, paxillin, ERK1/2 and Akt was significantly blocked by silencing SCGN. We conclude that SCGN controls glucose-stimulated insulin secretion and thus may be useful in the therapy of Type 2 diabetes. PMID:27095850

  8. Secretagogin affects insulin secretion in pancreatic β-cells by regulating actin dynamics and focal adhesion.

    PubMed

    Yang, Seo-Yun; Lee, Jae-Jin; Lee, Jin-Hee; Lee, Kyungeun; Oh, Seung Hoon; Lim, Yu-Mi; Lee, Myung-Shik; Lee, Kong-Joo

    2016-06-15

    Secretagogin (SCGN), a Ca(2+)-binding protein having six EF-hands, is selectively expressed in pancreatic β-cells and neuroendocrine cells. Previous studies suggested that SCGN enhances insulin secretion by functioning as a Ca(2+)-sensor protein, but the underlying mechanism has not been elucidated. The present study explored the mechanism by which SCGN enhances glucose-induced insulin secretion in NIT-1 insulinoma cells. To determine whether SCGN influences the first or second phase of insulin secretion, we examined how SCGN affects the kinetics of insulin secretion in NIT-1 cells. We found that silencing SCGN suppressed the second phase of insulin secretion induced by glucose and H2O2, but not the first phase induced by KCl stimulation. Recruitment of insulin granules in the second phase of insulin secretion was significantly impaired by knocking down SCGN in NIT-1 cells. In addition, we found that SCGN interacts with the actin cytoskeleton in the plasma membrane and regulates actin remodelling in a glucose-dependent manner. Since actin dynamics are known to regulate focal adhesion, a critical step in the second phase of insulin secretion, we examined the effect of silencing SCGN on focal adhesion molecules, including FAK (focal adhesion kinase) and paxillin, and the cell survival molecules ERK1/2 (extracellular-signal-regulated kinase 1/2) and Akt. We found that glucose- and H2O2-induced activation of FAK, paxillin, ERK1/2 and Akt was significantly blocked by silencing SCGN. We conclude that SCGN controls glucose-stimulated insulin secretion and thus may be useful in the therapy of Type 2 diabetes. PMID:27095850

  9. Molecular association of CD98, CD29, and CD147 critically mediates monocytic U937 cell adhesion

    PubMed Central

    Kim, Mi-Yeon

    2016-01-01

    Adhesion events of monocytes represent an important step in inflammatory responses induced by chemokines. The β1-integrin CD29 is a major adhesion molecule regulating leukocyte migration and extravasation. Although several adhesion molecules have been known as regulators of CD29, the molecular interactions between CD29 and its regulatory adhesion molecules (such as CD98 and CD147) have not been fully elucidated. Therefore, in this study, we examined whether these molecules are functionally, biochemically, and cell-biologically associated using monocytic U937 cells treated with aggregation-stimulating and blocking antibodies, as well as enzyme inhibitors. The surface levels of CD29, CD98, and CD147 (but not CD43, CD44, and CD82) were increased. The activation of CD29, CD98, and CD147 by ligation of them with aggregation-activating antibodies triggered the induction of cell-cell adhesion, and sensitivity to various enzyme inhibitors and aggregation-blocking antibodies was similar for CD29-, CD98-, and CD147-induced U937 cell aggregation. Molecular association between these molecules and the actin cytoskeleton was confirmed by confocal microscopy and immunoprecipitation. These results strongly suggest that CD29 might be modulated by its biochemical and cellular regulators, including CD98 and CD147, via the actin cytoskeleton. PMID:27610038

  10. Molecular association of CD98, CD29, and CD147 critically mediates monocytic U937 cell adhesion.

    PubMed

    Kim, Mi-Yeon; Cho, Jae Youl

    2016-09-01

    Adhesion events of monocytes represent an important step in inflammatory responses induced by chemokines. The β1-integrin CD29 is a major adhesion molecule regulating leukocyte migration and extravasation. Although several adhesion molecules have been known as regulators of CD29, the molecular interactions between CD29 and its regulatory adhesion molecules (such as CD98 and CD147) have not been fully elucidated. Therefore, in this study, we examined whether these molecules are functionally, biochemically, and cell-biologically associated using monocytic U937 cells treated with aggregation-stimulating and blocking antibodies, as well as enzyme inhibitors. The surface levels of CD29, CD98, and CD147 (but not CD43, CD44, and CD82) were increased. The activation of CD29, CD98, and CD147 by ligation of them with aggregation-activating antibodies triggered the induction of cell-cell adhesion, and sensitivity to various enzyme inhibitors and aggregation-blocking antibodies was similar for CD29-, CD98-, and CD147-induced U937 cell aggregation. Molecular association between these molecules and the actin cytoskeleton was confirmed by confocal microscopy and immunoprecipitation. These results strongly suggest that CD29 might be modulated by its biochemical and cellular regulators, including CD98 and CD147, via the actin cytoskeleton. PMID:27610038

  11. Mechanical force effect on the two-state equilibrium of the hyaluronan-binding domain of CD44 in cell rolling.

    PubMed

    Suzuki, Takashi; Suzuki, Miho; Ogino, Shinji; Umemoto, Ryo; Nishida, Noritaka; Shimada, Ichio

    2015-06-01

    CD44 is the receptor for hyaluronan (HA) and mediates cell rolling under fluid shear stress. The HA-binding domain (HABD) of CD44 interconverts between a low-affinity, ordered (O) state and a high-affinity, partially disordered (PD) state, by the conformational change of the C-terminal region, which is connected to the plasma membrane. To examine the role of tensile force on CD44-mediated rolling, we used a cell-free rolling system, in which recombinant HABDs were attached to beads through a C-terminal or N-terminal tag. We found that the rolling behavior was stabilized only at high shear stress, when the HABD was attached through the C-terminal tag. In contrast, no difference was observed for the beads coated with HABD mutants that constitutively adopt either the O state or the PD state. Steered molecular dynamics simulations suggested that the force from the C terminus disrupts the interaction between the C-terminal region and the core of the domain, thus providing structural insights into how the mechanical force triggers the allosteric O-to-PD transition. Based on these results, we propose that the force applied from the C terminus enhances the HABD-HA interactions by inducing the conformational change to the high-affinity PD transition more rapidly, thereby enabling CD44 to mediate lymphocyte trafficking and hematopoietic progenitor cell homing under high-shear conditions. PMID:26038553

  12. Sonic hedgehog-glioma associated oncogene homolog 1 signaling enhances drug resistance in CD44(+)/Musashi-1(+) gastric cancer stem cells.

    PubMed

    Xu, Min; Gong, Aihua; Yang, Hongqiong; George, Suraj K; Jiao, Zhijun; Huang, Hongmei; Jiang, Xiaomeng; Zhang, Youli

    2015-12-01

    Drug resistance in gastric cancer largely results from the gastric cancer stem cells (GCSCs), which could be targeted to improve the efficacy of chemotherapy. In this study, we identified a subpopulation of GCSCs enriched in holoclones that expressed CD44(+)/Musashi-1(+) stem cell biomarkers, capable of self-renewal and proliferation. Enriched CD44(+)/Musashi-1(+) GCSCs demonstrated elevated expression of sonic hedgehog (SHH) and glioma-associated oncogene homolog 1 (GLI1), the well-known signaling pathway molecules involved in the drug resistance. Further, CD44(+)/Musashi-1(+) cells exhibited high drug efflux bump activity and were resistant to doxorubicin (Dox)-induced apoptosis, and unregulated the ATP-binding cassette sub-family G member 2 (ABCG2) expression,. The above effects on apoptosis were reversed in the presence of GLI inhibitors, GANT61 and GDC-0449, or by the knockdown of GLI1/SHH. Upon knockdown of GLI1, expression of ABCG2 was downregulated the antitumor effects were significantly improved as observed in the gastric cancer xenograft. Collectively, our study revealed that co-expression of CD44(+)/Musashi-1(+) could be used to identify GCSCs, which also accounts for the drug resistance in gastric cancer. SHH-GLI and its downstream effector ABCG2 could be better targeted to possibly improve the efficacy of chemotherapy in drug-resistant gastric cancers. PMID:26276718

  13. CD44v6 Monoclonal Antibody-Conjugated Gold Nanostars for Targeted Photoacoustic Imaging and Plasmonic Photothermal Therapy of Gastric Cancer Stem-like Cells

    PubMed Central

    Liang, Shujing; Li, Chao; Zhang, Chunlei; Chen, Yunsheng; Xu, Liang; Bao, Chenchen; Wang, Xiaoyong; liu, Gang; zhang, Fengchun; Cui, Daxiang

    2015-01-01

    Developing safe and effective nanoprobes for targeted imaging and selective therapy of gastric cancer stem cells (GCSCs) has become one of the most promising anticancer strategies. Herein, gold nanostars-based PEGylated multifunctional nanoprobes were prepared with conjugated CD44v6 monoclonal antibodies (CD44v6-GNS) as the targeting ligands. It was observed that the prepared nanoprobes had high affinity towards GCSC spheroid colonies and destroyed them completely with a low power density upon near-infrared (NIR) laser treatment (790 nm, 1.5 W/cm2, 5 min) in vitro experiment. Orthotopic and subcutaneous xenografted nude mice models of human gastric cancer were established. Subsequently, biodistribution and photothermal therapeutic effects after being intravenously injected with the prepared nanoprobes were assessed. Photoacoustic imaging revealed that CD44v6-GNS nanoprobes could target the gastric cancer vascular system actively at 4 h post-injection, while the probes inhibited tumor growth remarkably upon NIR laser irradiation, and even extended survivability of the gastric cancer-bearing mice. The CD44v6-GNS nanoprobes exhibited great potential for applications of gastric cancer targeted imaging and photothermal therapy in the near future. PMID:26155313

  14. Rasgrp1 mutation increases naïve T-cell CD44 expression and drives mTOR-dependent accumulation of Helios+ T cells and autoantibodies

    PubMed Central

    Myers, Darienne R; Polakos, Noelle K; Enders, Anselm; Roots, Carla; Balakishnan, Bhavani; Miosge, Lisa A; Sjollema, Geoff; Bertram, Edward M; Field, Matthew A; Shao, Yunli; Andrews, T Daniel; Whittle, Belinda; Barnes, S Whitney; Walker, John R; Cyster, Jason G

    2013-01-01

    Missense variants are a major source of human genetic variation. Here we analyze a new mouse missense variant, Rasgrp1Anaef, with an ENU-mutated EF hand in the Rasgrp1 Ras guanine nucleotide exchange factor. Rasgrp1Anaef mice exhibit anti-nuclear autoantibodies and gradually accumulate a CD44hi Helios+ PD-1+ CD4+ T cell population that is dependent on B cells. Despite reduced Rasgrp1-Ras-ERK activation in vitro, thymocyte selection in Rasgrp1Anaef is mostly normal in vivo, although CD44 is overexpressed on naïve thymocytes and T cells in a T-cell-autonomous manner. We identify CD44 expression as a sensitive reporter of tonic mTOR-S6 kinase signaling through a novel mouse strain, chino, with a reduction-of-function mutation in Mtor. Elevated tonic mTOR-S6 signaling occurs in Rasgrp1Anaef naïve CD4+ T cells. CD44 expression, CD4+ T cell subset ratios and serum autoantibodies all returned to normal in Rasgrp1AnaefMtorchino double-mutant mice, demonstrating that increased mTOR activity is essential for the Rasgrp1Anaef T cell dysregulation. DOI: http://dx.doi.org/10.7554/eLife.01020.001 PMID:24336796

  15. Regulation of platelet biology by platelet endothelial cell adhesion molecule-1.

    PubMed

    Jones, Chris I; Moraes, Leonardo A; Gibbins, Jonathan M

    2012-01-01

    Platelet endothelial cell adhesion molecule-1 (PECAM-1), an immunoreceptor tyrosine-based inhibitory motif containing receptor, plays diverse and apparently contradictory roles in regulating the response of platelets to stimuli; inhibiting platelet response to immunoreceptor tyrosine-based activation motif and G protein-coupled receptor signalling following stimulation with collagen, adenosine diphosphate, and thrombin, as well as enhancing integrin outside-in signalling. These dual, and opposing, roles suggest an important and complex role for PECAM-1 in orchestrating platelet response to vascular damage. Indeed, during thrombus formation, the influence of PECAM-1 on the multiple signalling pathways combines leading to a relatively large inhibitory effect on thrombus formation. PMID:22035359

  16. Analysis of Post-Traumatic Brain Injury Gene Expression Signature Reveals Tubulins, Nfe2l2, Nfkb, Cd44, and S100a4 as Treatment Targets

    PubMed Central

    Lipponen, Anssi; Paananen, Jussi; Puhakka, Noora; Pitkänen, Asla

    2016-01-01

    We aimed to define the chronically altered gene expression signature of traumatic brain injury (TBI-sig) to discover novel treatments to reverse pathologic gene expression or reinforce the expression of recovery-related genes. Genome-wide RNA-sequencing was performed at 3 months post-TBI induced by lateral fluid-percussion injury in rats. We found 4964 regulated genes in the perilesional cortex and 1966 in the thalamus (FDR < 0.05). TBI-sig was used for a LINCS analysis which identified 11 compounds that showed a strong connectivity with the TBI-sig in neuronal cell lines. Of these, celecoxib and sirolimus were recently reported to have a disease-modifying effect in in vivo animal models of epilepsy. Other compounds revealed by the analysis were BRD-K91844626, BRD-A11009626, NO-ASA, BRD-K55260239, SDZ-NKT-343, STK-661558, BRD-K75971499, ionomycin, and desmethylclomipramine. Network analysis of overlapping genes revealed the effects on tubulins (Tubb2a, Tubb3, Tubb4b), Nfe2l2, S100a4, Cd44, and Nfkb2, all of which are linked to TBI-relevant outcomes, including epileptogenesis and tissue repair. Desmethylclomipramine modulated most of the gene targets considered favorable for TBI outcome. Our data demonstrate long-lasting transcriptomics changes after TBI. LINCS analysis predicted that these changes could be modulated by various compounds, some of which are already in clinical use but never tested in TBI. PMID:27530814

  17. Analysis of Post-Traumatic Brain Injury Gene Expression Signature Reveals Tubulins, Nfe2l2, Nfkb, Cd44, and S100a4 as Treatment Targets.

    PubMed

    Lipponen, Anssi; Paananen, Jussi; Puhakka, Noora; Pitkänen, Asla

    2016-01-01

    We aimed to define the chronically altered gene expression signature of traumatic brain injury (TBI-sig) to discover novel treatments to reverse pathologic gene expression or reinforce the expression of recovery-related genes. Genome-wide RNA-sequencing was performed at 3 months post-TBI induced by lateral fluid-percussion injury in rats. We found 4964 regulated genes in the perilesional cortex and 1966 in the thalamus (FDR < 0.05). TBI-sig was used for a LINCS analysis which identified 11 compounds that showed a strong connectivity with the TBI-sig in neuronal cell lines. Of these, celecoxib and sirolimus were recently reported to have a disease-modifying effect in in vivo animal models of epilepsy. Other compounds revealed by the analysis were BRD-K91844626, BRD-A11009626, NO-ASA, BRD-K55260239, SDZ-NKT-343, STK-661558, BRD-K75971499, ionomycin, and desmethylclomipramine. Network analysis of overlapping genes revealed the effects on tubulins (Tubb2a, Tubb3, Tubb4b), Nfe2l2, S100a4, Cd44, and Nfkb2, all of which are linked to TBI-relevant outcomes, including epileptogenesis and tissue repair. Desmethylclomipramine modulated most of the gene targets considered favorable for TBI outcome. Our data demonstrate long-lasting transcriptomics changes after TBI. LINCS analysis predicted that these changes could be modulated by various compounds, some of which are already in clinical use but never tested in TBI. PMID:27530814

  18. Analysis of anomalous CD44 gene expression in human breast, bladder, and colon cancer and correlation of observed mRNA and protein isoforms.

    PubMed Central

    Woodman, A. C.; Sugiyama, M.; Yoshida, K.; Sugino, T.; Borgya, A.; Goodison, S.; Matsumura, Y.; Tarin, D.

    1996-01-01

    Many studies have now demonstrated disorganized overexpression of the CD44 gene in various types of human malignant tumors, and this abnormality has emerged as an interesting candidate marker for early cancer diagnosis. The purpose of this work was to analyze and compare the patterns of transcription and translation of this gene in human breast (ZR75-1; MDAMB-435 clone 4A4) and colon (HT29) tumor cell lines and in tumors of the breast, bladder, and colon, with the aim of identifying the most suitable analyte for diagnostic purposes. Transcription was studied by reverse transcription-polymerase chain reaction using CD44-specific primers and probes complementary to exons in the standard (exons 3 to 5 and 16 to 18) and variably expressed regions of this gene (exons 7, 8, 10, 11, and 15). Translation was investigated by Western blot analysis and immunohistochemistry using monoclonal antibodies specific to the standard form of CD44 and to the products of the same variant exons. Southern blot hybridization analysis of the reverse transcription-polymerase chain reaction products showed a large number of CD44 transcripts in tumor cells. Direct comparison of these Southern blots with Western blots on matched tumor-cell-line extracts indicated that most of the diverse mRNA isoforms did not detectably translate into proteins. However, immunohistochemistry of normal and malignant breast (n = 17 and 23, respectively), bladder (n = 5 and 19), and colon (n = 19 and 19) tissue specimens showed increased staining of CD44 standard and CD44 variant proteins in the carcinoma cells. Combination of this information with the data from reverse transcription-polymerase chain reaction and Western blot analysis indicates that the overexpression at the protein level involves only a minority of the aberrant RNA transcripts. We conclude that the development of methods for the accurate quantitation of over-abundant CD44 RNA species in clinical samples offers the most promising approach to

  19. Dual-targeting hybrid nanoparticles for the delivery of SN38 to Her2 and CD44 overexpressed human gastric cancer

    NASA Astrophysics Data System (ADS)

    Yang, Zhe; Luo, Huiyan; Cao, Zhong; Chen, Ya; Gao, Jinbiao; Li, Yingqin; Jiang, Qing; Xu, Ruihua; Liu, Jie

    2016-06-01

    Gastric cancer (GC), particularly of the type with high expression of both human epidermal growth factor receptor 2 (Her2) and cluster determinant 44 (CD44), is one of the most malignant human tumors which causes a high mortality rate due to rapid tumor growth and metastasis. To develop effective therapeutic treatments, a dual-targeting hybrid nanoparticle (NP) system was designed and constructed to deliver the SN38 agent specifically to human solid gastric tumors bearing excessive Her2 and CD44. The hybrid NPs consist of a particle core made of the biodegradable polymer PLGA and a lipoid shell prepared by conjugating the AHNP peptides and n-hexadecylamine (HDA) to the carboxyl groups of hyaluronic acid (HA). Upon encapsulation of the SN38 agent in the NPs, the AHNP peptides and HA on the NP surface allow preferential delivery of the drug to gastric cancer cells (e.g., HGC27 cells) by targeting Her2 and CD44. Cellular uptake and in vivo biodistribution experiments verified the active targeting and prolonged in vivo circulation properties of the dual-targeting hybrid NPs, leading to enhanced accumulation of the drug in tumors. Furthermore, the anti-proliferation mechanism studies revealed that the inhibition of the growth and invasive activity of HGC27 cells was not only attributed to the enhanced cellular uptake of dual-targeting NPs, but also benefited from the suppression of CD44 and Her2 expression by HA and AHNP moieties. Finally, intravenous administration of the SN38-loaded dual-targeting hybrid NPs induced significant growth inhibition of HGC27 tumor xenografted in nude mice compared with a clinical antitumor agent, Irinotecan (CPT-11), and the other NP formulations. These results demonstrate that the designed dual-targeting hybrid NPs are promising for targeted anti-cancer drug delivery to treat human gastric tumors over-expressing Her2 and CD44.Gastric cancer (GC), particularly of the type with high expression of both human epidermal growth factor receptor

  20. Characterization of the role of cadherin in regulating cell adhesion during sea urchin development.

    PubMed

    Miller, J R; McClay, D R

    1997-12-15

    During development, the modulation of cadherin adhesive function is proposed to control various morphogenetic events including epithelial-mesenchymal conversions and tubulogenesis, although the mechanisms responsible for regulating cadherin activity during these events remain unclear. In order to gain insights into the regulation of cadherin function during morphogenesis, we utilized the sea urchin embryo as a model system to study the regulation of cadherin localization during epithelial-mesenchymal conversion and convergent-extension movements. Polyclonal antibodies raised against the cytoplasmic domain of a cloned sea urchin cadherin recognize three major polypeptides of M(r) 320, 140, and 125 kDa and specifically stain adherens junctions, and to a lesser extent, lateral membrane domains in all epithelial tissues of the embryo. Analysis of embryos during gastrulation demonstrates that changes in cadherin localization are observed in cells undergoing an epithelial-mesenchymal conversion. Ingression of primary mesenchyme cells is accompanied by the rapid loss of junctional cadherin staining and the coincident accumulation of cadherin in intracellular organelles. These data are consistent with the idea that the deadhesion of mesenchymal cells from neighboring epithelial cells involves the regulated endocytosis of cell surface cadherin molecules. Conversely, neither cadherin abundance nor localization is altered in cells of the gut which undergo convergent-extension movements during the formation of the archenteron. This observation indicates that these movements do not require the loss of junctional cadherin molecules. Instead, the necessary balance between adhesion and motility may be achieved by regulating the expression of different subtypes of cadherin molecules or modifying interactions between cadherins and catenins, proteins that bind the cytoplasmic domain of cadherin and are necessary for cadherin adhesive function. To address cadherin function at the

  1. Dual-targeting hybrid nanoparticles for the delivery of SN38 to Her2 and CD44 overexpressed human gastric cancer.

    PubMed

    Yang, Zhe; Luo, Huiyan; Cao, Zhong; Chen, Ya; Gao, Jinbiao; Li, Yingqin; Jiang, Qing; Xu, Ruihua; Liu, Jie

    2016-06-01

    Gastric cancer (GC), particularly of the type with high expression of both human epidermal growth factor receptor 2 (Her2) and cluster determinant 44 (CD44), is one of the most malignant human tumors which causes a high mortality rate due to rapid tumor growth and metastasis. To develop effective therapeutic treatments, a dual-targeting hybrid nanoparticle (NP) system was designed and constructed to deliver the SN38 agent specifically to human solid gastric tumors bearing excessive Her2 and CD44. The hybrid NPs consist of a particle core made of the biodegradable polymer PLGA and a lipoid shell prepared by conjugating the AHNP peptides and n-hexadecylamine (HDA) to the carboxyl groups of hyaluronic acid (HA). Upon encapsulation of the SN38 agent in the NPs, the AHNP peptides and HA on the NP surface allow preferential delivery of the drug to gastric cancer cells (e.g., HGC27 cells) by targeting Her2 and CD44. Cellular uptake and in vivo biodistribution experiments verified the active targeting and prolonged in vivo circulation properties of the dual-targeting hybrid NPs, leading to enhanced accumulation of the drug in tumors. Furthermore, the anti-proliferation mechanism studies revealed that the inhibition of the growth and invasive activity of HGC27 cells was not only attributed to the enhanced cellular uptake of dual-targeting NPs, but also benefited from the suppression of CD44 and Her2 expression by HA and AHNP moieties. Finally, intravenous administration of the SN38-loaded dual-targeting hybrid NPs induced significant growth inhibition of HGC27 tumor xenografted in nude mice compared with a clinical antitumor agent, Irinotecan (CPT-11), and the other NP formulations. These results demonstrate that the designed dual-targeting hybrid NPs are promising for targeted anti-cancer drug delivery to treat human gastric tumors over-expressing Her2 and CD44. PMID:27203688

  2. Adhesion and migration of polymorphonuclear leukocytes across human brain microvessel endothelial cells are differentially regulated by endothelial cell adhesion molecules and modulate monolayer permeability.

    PubMed

    Wong, Donald; Prameya, Rukmini; Dorovini-Zis, Katerina

    2007-03-01

    The mechanisms by which polymorphonuclear leukocytes (PMN) cross the human blood-brain barrier have not been fully elucidated. Using a well characterized in vitro model of the human BBB, we examined the role of endothelial cell adhesion molecules on the adhesion and transendothelial migration of PMN across primary cultures of human brain microvessel endothelial cells (HBMEC). A small number of PMN (0.06%) adhered to unstimulated HBMEC, and the basal adhesion was not affected by anti-adhesion molecule antibodies. Treatment of HBMEC with tumor necrosis factor (TNF)-alpha resulted in increased PMN adhesion that was significantly inhibited by blocking antibodies to E-selectin and ICAM-1, but not VCAM-1 or PECAM-1. A very small number of adherent PMN migrated across unstimulated HBMEC monolayers. Migration increased 2 to 20 fold following stimulation of HBMEC with TNF-alpha. Monoclonal antibody blocking studies showed that PMN used ICAM-1, but not VCAM-1, E-selectin or PECAM-1 to move across activated monolayers. Anti-adhesion molecule antibodies did not diminish the basal PMN migration. Ultrastructurally, PMN often aggregated on top and between adjacent endothelial cells and adhered by first extending pseudopodia along the apical endothelial surface. They then flattened and inserted themselves between endothelial cells in order to migrate across the monolayers. At the end of the migration period, the cultures resumed their continuity with no evidence of disruption. Transendothelial migration of PMN decreased the transendothelial electrical resistance and increased the permeability to horseradish peroxidase, which penetrated alongside the migrating leukocytes. A blocking antibody to ICAM-1 that greatly decreased migration, had no effect on the permeability changes. These studies provide insights into the mechanisms that regulate the entry of PMN into the brain and the increased permeability of the BBB in CNS inflammation. PMID:17291598

  3. SynCAM 1 Adhesion Dynamically Regulates Synapse Number and Impacts Plasticity and Learning

    PubMed Central

    Robbins, Elissa M.; Krupp, Alexander J.; de Arce, Karen Perez; Ghosh, Ananda K.; Fogel, Adam I.; Boucard, Antony; Südhof, Thomas C.; Stein, Valentin; Biederer, Thomas

    2010-01-01

    Summary Synaptogenesis is required for wiring neuronal circuits in the developing brain and continues to remodel adult networks. However, the molecules organizing synapse development and maintenance in vivo remain incompletely understood. We now demonstrate that the immunoglobulin adhesion molecule SynCAM 1 dynamically alters synapse number and plasticity. Overexpression of SynCAM 1 in transgenic mice promotes excitatory synapse number, while loss of SynCAM 1 results in fewer excitatory synapses. By turning off SynCAM 1 overexpression in transgenic brains, we show that it maintains the newly induced synapses. SynCAM 1 also functions at mature synapses to alter their plasticity by regulating long-term depression. Consistent with these effects on neuronal connectivity, SynCAM 1 expression affects spatial learning, with knock-out mice learning better. The reciprocal effects of increased SynCAM 1 expression and loss reveal that this adhesion molecule contributes to the regulation of synapse number and plasticity, and impacts how neuronal networks undergo activity-dependent changes. PMID:21145003

  4. PAK-PIX interactions regulate adhesion dynamics and membrane protrusion to control neurite outgrowth.

    PubMed

    Santiago-Medina, Miguel; Gregus, Kelly A; Gomez, Timothy M

    2013-03-01

    The roles of P21-activated kinase (PAK) in the regulation of axon outgrowth downstream of extracellular matrix (ECM) proteins are poorly understood. Here we show that PAK1-3 and PIX are expressed in the developing spinal cord and differentially localize to point contacts and filopodial tips within motile growth cones. Using a specific interfering peptide called PAK18, we found that axon outgrowth is robustly stimulated on laminin by partial inhibition of PAK-PIX interactions and PAK function, whereas complete inhibition of PAK function stalls axon outgrowth. Furthermore, modest inhibition of PAK-PIX stimulates the assembly and turnover of growth cone point contacts, whereas strong inhibition over-stabilizes adhesions. Point mutations within PAK confirm the importance of PIX binding. Together our data suggest that regulation of PAK-PIX interactions in growth cones controls neurite outgrowth by influencing the activity of several important mediators of actin filament polymerization and retrograde flow, as well as integrin-dependent adhesion to laminin. PMID:23321640

  5. Extracellular Matrix Rigidity-dependent Sphingosine-1-phosphate Secretion Regulates Metastatic Cancer Cell Invasion and Adhesion

    PubMed Central

    Ko, Panseon; Kim, Daehwan; You, Eunae; Jung, Jangho; Oh, Somi; Kim, Jaehyun; Lee, Kwang-Ho; Rhee, Sangmyung

    2016-01-01

    Dynamic interaction between cancer cells and the surrounding microenvironment is critical for cancer progression via changes in cellular behavior including alteration of secreted molecules. However, the molecular mechanisms underlying the influence exerted by the cancer microenvironment on secretion of molecules during cancer progression remain largely unknown. In this study, we report that secretion of spingsine-1-phosphate (S1P) and its regulator, SphK1 expression is dependent of the substrate rigidity, which is critical for the balance between cancer cell invasion and adhesion. Conditioned media (CM) of MDA-MB-231, an aggressive breast cancer cell obtained from soft substrate (~0.5 kPa) induced chemo-attractive invasion, while CM obtained from stiff substrate (~2.5 kPa) increased cell adhesion instead. We found that the expression of SphK1 is upregulated in the stiff substrate, resulting in an increase in S1P levels in the CM. We also found that upregulation of SphK1 expression in the stiff substrate is dominant in metastatic cancer cells but not in primary cancer cells. These results suggest that alterations in the mechanical environment of the ECM surrounding the tumor cells actively regulate cellular properties such as secretion, which in turn, may contribute to cancer progression. PMID:26877098

  6. β-Catenin–regulated myeloid cell adhesion and migration determine wound healing

    PubMed Central

    Amini-Nik, Saeid; Cambridge, Elizabeth; Yu, Winston; Guo, Anne; Whetstone, Heather; Nadesan, Puviindran; Poon, Raymond; Hinz, Boris; Alman, Benjamin A.

    2014-01-01

    A β-catenin/T cell factor–dependent transcriptional program is critical during cutaneous wound repair for the regulation of scar size; however, the relative contribution of β-catenin activity and function in specific cell types in the granulation tissue during the healing process is unknown. Here, cell lineage tracing revealed that cells in which β-catenin is transcriptionally active express a gene profile that is characteristic of the myeloid lineage. Mice harboring a macrophage-specific deletion of the gene encoding β-catenin exhibited insufficient skin wound healing due to macrophage-specific defects in migration, adhesion to fibroblasts, and ability to produce TGF-β1. In irradiated mice, only macrophages expressing β-catenin were able to rescue wound-healing deficiency. Evaluation of scar tissue collected from patients with hypertrophic and normal scars revealed a correlation between the number of macrophages within the wound, β-catenin levels, and cellularity. Our data indicate that β-catenin regulates myeloid cell motility and adhesion and that β-catenin–mediated macrophage motility contributes to the number of mesenchymal cells and ultimate scar size following cutaneous injury. PMID:24837430

  7. Extracellular Matrix Rigidity-dependent Sphingosine-1-phosphate Secretion Regulates Metastatic Cancer Cell Invasion and Adhesion.

    PubMed

    Ko, Panseon; Kim, Daehwan; You, Eunae; Jung, Jangho; Oh, Somi; Kim, Jaehyun; Lee, Kwang-Ho; Rhee, Sangmyung

    2016-01-01

    Dynamic interaction between cancer cells and the surrounding microenvironment is critical for cancer progression via changes in cellular behavior including alteration of secreted molecules. However, the molecular mechanisms underlying the influence exerted by the cancer microenvironment on secretion of molecules during cancer progression remain largely unknown. In this study, we report that secretion of spingsine-1-phosphate (S1P) and its regulator, SphK1 expression is dependent of the substrate rigidity, which is critical for the balance between cancer cell invasion and adhesion. Conditioned media (CM) of MDA-MB-231, an aggressive breast cancer cell obtained from soft substrate (~0.5 kPa) induced chemo-attractive invasion, while CM obtained from stiff substrate (~2.5 kPa) increased cell adhesion instead. We found that the expression of SphK1 is upregulated in the stiff substrate, resulting in an increase in S1P levels in the CM. We also found that upregulation of SphK1 expression in the stiff substrate is dominant in metastatic cancer cells but not in primary cancer cells. These results suggest that alterations in the mechanical environment of the ECM surrounding the tumor cells actively regulate cellular properties such as secretion, which in turn, may contribute to cancer progression. PMID:26877098

  8. Stem cell differentiation increases membrane-actin adhesion regulating cell blebability, migration and mechanics

    PubMed Central

    Sliogeryte, Kristina; Thorpe, Stephen D.; Lee, David A.; Botto, Lorenzo; Knight, Martin M.

    2014-01-01

    This study examines how differentiation of human mesenchymal stem cells regulates the interaction between the cell membrane and the actin cortex controlling cell behavior. Micropipette aspiration was used to measure the pressure required for membrane-cortex detachment which increased from 0.15 kPa in stem cells to 0.71 kPa following chondrogenic differentiation. This effect was associated with reduced susceptibility to mechanical and osmotic bleb formation, reduced migration and an increase in cell modulus. Theoretical modelling of bleb formation demonstrated that the increased stiffness of differentiated cells was due to the increased membrane-cortex adhesion. Differentiated cells exhibited greater F-actin density and slower actin remodelling. Differentiated cells also expressed greater levels of the membrane-cortex ezrin, radixin, moeisin (ERM) linker proteins which was responsible for the reduced blebability, as confirmed by transfection of stem cells with dominant active ezrin-T567D-GFP. This study demonstrates that stem cells have an inherently weak membrane-cortex adhesion which increases blebability thereby regulating cell migration and stiffness. PMID:25471686

  9. Label-free proteomics uncovers energy metabolism and focal adhesion regulations responsive for endometrium receptivity.

    PubMed

    Chen, Qian; Zhang, Aijun; Yu, Feng; Gao, Jing; Liu, Yue; Yu, Chengli; Zhou, Hu; Xu, Chen

    2015-04-01

    The menstrual cycle of the female uterus leads to periodic changes of the endometrium. These changes are important for developing the endometrial receptivity and for achieving competency of embryo implantation. However, the molecular events underlying the endometrial receptivity process remain poorly understood. Here we applied an LC-MS-based label-free quantitative proteomic approach to compare the endometrial tissues in the midsecretory (receptive) phase with the endometrial tissues in the proliferative phase from age-matched woman (n = 6/group). The proteomes of endometrial tissues were extracted using an SDS-based detergent, digested by the filter-aided sample preparation procedures, and subsequently analyzed by nano-LC-MS/MS (Orbitrap XL) with a 4 h gradient. Reliable protein expression profiles were reproducibly obtained from the endometrial tissues in the receptive and proliferative phases. A total of 2138 protein groups were quantified under highly stringent criteria with a false discovery rate of <1% for peptide and protein groups. Among these proteins, 317 proteins had differences in expression that were statistically significant between the receptive and proliferative phases. Direct protein-protein interaction network analyses of these significantly changed proteins showed that the up-regulation of creatine kinase B-type (CKB) in the receptive phase may be related to endometrium receptivity. The interaction network also showed that proteins related to cell-cell adhesion were down-regulated. Moreover, the results from KEGG pathway analyses are consistent with the protein-protein interaction results. The proteins, including alpha-actinin (ACTN), extracellular matrix proteins, integrin alpha-V, and so on, that are involved in the focal adhesion pathway were down-regulated in the receptive phase compared with the proliferative phase, which may facilitate the implantation of the fertilized ovum. Selected proteins were validated by Western blot analysis and

  10. Regulation of ionizing radiation-induced adhesion of breast cancer cells to fibronectin by alpha5beta1 integrin.

    PubMed

    Lee, Shin Hee; Cheng, Huiwen; Yuan, Ye; Wu, Shiyong

    2014-06-01

    Ionizing radiation (IR) is commonly used for cancer therapy, however, its potential influence on cancer metastatic potential remains controversial. In this study, we elucidated the role of integrins in regulation of IR-altered adhesion between breast cancer cells and extracellular matrix (ECM) proteins, which is a key step in the initial phase of metastasis. Our data suggest that the extent of effect that ionizing radiation had on cell adhesion depended on the genetic background of the breast cancer cells. Ionizing radiation was a better adhesion inducer for p53-mutated cells, such as MDA-MB-231 cells, than for p53 wild-type cells, such as MCF-7 cells. While IR-induced adhesions between MDA-MB-231 cells to fibronectin, laminin, collagen I and collagen IV, only blocking of the adhesion between α5β1 integrin and fibronectin using anti-α5β1 integrin antibody could completely inhibit the radiation-induced adhesion of the cells. A soluble Arg-Gly-Asp peptide, the binding motif for fibronectin binding integrins, could also reduce the adhesion of the cells to fibronectin with or without ionizing radiation exposure. The inhibition of the cell-fibronectin interaction also affected, but did not always correlate with, transwell migration of the cancer cells. In addition, our data showed that the total expression of α5 integrin and surface expression of α5β1 integrin were increased in the cells treated with ionizing radiation. The increased surface expression of α5β1 integrin, along with the adhesion between the cells and fibronectin, could be inhibited by both ataxia telangiectasia mutated (ATM) and Rad3-related (ATR) kinase inhibitors. These results suggested that ATM/ATR-mediated surface expression of α5β1 integrin might play a central role in regulation of ionizing radiation-altered adhesion. PMID:24785587

  11. Organ-selective regulation of vascular adhesion protein-1 expression in man.

    PubMed

    Arvilommi, A M; Salmi, M; Jalkanen, S

    1997-07-01

    Vascular adhesion protein-1 (VAP-1) is an endothelial molecule which mediates lymphocyte binding to endothelium in peripheral lymph nodes and at certain sites of inflammation. The expression of VAP-1 in vivo is strongly up-regulated in inflamed tissues, such as gut and skin. The purpose of this work was to examine the factors responsible for this induction of VAP-1. Since the expression of VAP-1 could not be induced in cultured endothelial cells with a large panel of mediators, we used an organ culture technique for the investigation of the regulation of VAP-1 expression in a more physiological micromilieu. Indeed, we found that the expression of endothelial VAP-1 could be up-regulated in human tonsillar tissue with interleukin (IL)-1, IL-4, tumor necrosis factor (TNF-alpha), interferon (IFN)-gamma and lipopolysaccharide, whereas histamine, thrombin, dibutyryl cAMP, N-formyl-Met-Leu-Phe (fMLP) and phorbol 12-myristate 13-acetate (PMA) had no effect. The induced VAP-1 protein was similar in molecular weight to the non-induced VAP-1, suggesting that VAP-1 synthesized de novo carries appropriate carbohydrate moieties. In contrast to tonsil organ culture, similar inductions performed with human appendix showed no up-regulation of VAP-1 expression, indicating that the regulation of VAP-1 expression exhibits organ-selective characteristics. Furthermore, in these tissues the smooth muscle cells, which constitutively express VAP-1, could not be stimulated to alter their level of expression of this molecule. In conclusion, the expression of VAP-1 can be markedly up-regulated with several mediators in tonsil but not in appendix organ culture, whereas cultured endothelial cells cannot be induced to express VAP-1. These results indicate that the expression of VAP-1 is regulated in a tissue- and cell type-selective manner, and a correct micromilieu is required for the up-regulation to occur. PMID:9247594

  12. Features of CD44+/CD24-low phenotypic cell distribution in relation to predictive markers and molecular subtypes of invasive ductal carcinoma of the breast.

    PubMed

    Gudadze, M; Kankava, Q; Mariamidze, A; Burkadze, G

    2014-03-01

    Breast cancer is the most widespread pathology among women. Despite the current progresses in research and treatment of metastatic breast cancer, mortality caused by this disease is still high, because above mentioned therapy is limited due to existence of cells resistant to therapy . Cancer stem cells are the only cells with ability of unlimited proliferative activity and cancerous potential, thus, they participate in the growth, progression and dissemination of cancer. Cancer stem cells are resistant to various forms of therapy, including chemotherapy and radiotherapy . Results of examination showed that 50% of all cases are positive on so called markers of stem cells, thus 45% of cases are negative. CD44+/CD24-low cases (cases that reveal stem cell-phenotype) in the group of invasive ductal carcinoma of Luminal A molecular subtype are almost as many as CD44+/CD24+ and CD44-/CD24+ phenotype cancers. In this group non-stem phenotype cases are 65%, so 5 times more than stem cell phenotype cancers. 1324 postoperative breast materials studied through 2008-2012 at the laboratory of "Pathgeo-Union of Pathologists" LTD and Academician N. Kipshidze Central University Clinic were used as test materials and specimens from 393 patients with invasive ductal carcinoma were selected. CD44/CD24 markers' expression in phenotypically different cancers and clinic-pathologic parameters as well as various biological features was conducted by the Pearson's correlation analysis and using X2 test. Statistical analysis of obtained numeral data was held using SPSS V.19.0 program. Confidence interval of 95% was considered statistically significant. Stem cell phenotype positive cases are with the highest percentage represented in Luminal B and basal-like molecular subgroup that to our minds is associated with their aggressive behavior and resistance to chemotherapy. Relatively good prognosis and response to chemotherapy of Luminal A molecular subtype cancers are to be stipulated by lower

  13. The Neuroplastin adhesion molecules: key regulators of neuronal plasticity and synaptic function.

    PubMed

    Beesley, Philip W; Herrera-Molina, Rodrigo; Smalla, Karl-Heinz; Seidenbecher, Constanze

    2014-11-01

    The Neuroplastins Np65 and Np55 are neuronal and synapse-enriched immunoglobulin superfamily molecules that play important roles in a number of key neuronal and synaptic functions including, for Np65, cell adhesion. In this review we focus on the physiological roles of the Neuroplastins in promoting neurite outgrowth, regulating the structure and function of both inhibitory and excitatory synapses in brain, and in neuronal and synaptic plasticity. We discuss the underlying molecular and cellular mechanisms by which the Neuroplastins exert their physiological effects and how these are dependent upon the structural features of Np65 and Np55, which enable them to bind to a diverse range of protein partners. In turn this enables the Neuroplastins to interact with a number of key neuronal signalling cascades. These include: binding to and activation of the fibroblast growth factor receptor; Np65 trans-homophilic binding leading to activation of p38 MAPK and internalization of glutamate (GluR1) receptor subunits; acting as accessory proteins for monocarboxylate transporters, thus affecting neuronal energy supply, and binding to GABAA α1, 2 and 5 subunits, thus regulating the composition and localization of GABAA receptors. An emerging theme is the role of the Neuroplastins in regulating the trafficking and subcellular localization of specific binding partners. We also discuss the involvement of Neuroplastins in a number of pathophysiological conditions, including ischaemia, schizophrenia and breast cancer and the role of a single nucleotide polymorphism in the human Neuroplastin (NPTN) gene locus in impairment of cortical development and cognitive functions. Neuroplastins are neuronal cell adhesion molecules, which induce neurite outgrowth and play important roles in synaptic maturation and plasticity. This review summarizes the functional implications of Neuroplastins for correct synaptic membrane protein localization, neuronal energy supply, expression of LTP and LTD

  14. Focal adhesion kinase regulation in stem cell alignment and spreading on nanofibers.

    PubMed

    Andalib, Mohammad Nahid; Lee, Jeong Soon; Ha, Ligyeom; Dzenis, Yuris; Lim, Jung Yul

    2016-05-13

    While electrospun nanofibers have demonstrated the potential for novel tissue engineering scaffolds, very little is known about the molecular mechanism of how cells sense and adapt to nanofibers. Here, we revealed the role of focal adhesion kinase (FAK), one of the key molecular sensors in the focal adhesion complex, in regulating mesenchymal stem cell (MSC) shaping on nanofibers. We produced uniaxially aligned and randomly distributed nanofibers from poly(l-lactic acid) to have the same diameters (about 130 nm) and evaluated MSC behavior on these nanofibers comparing with that on flat PLLA control. C3H10T1/2 murine MSCs exhibited upregulations in FAK expression and phosphorylation (pY397) on nanofibrous cultures as assessed by immunoblotting, and this trend was even greater on aligned nanofibers. MSCs showed significantly elongated and well-spread morphologies on aligned and random nanofibers, respectively. In the presence of FAK silencing via small hairpin RNA (shRNA), cell elongation length in the aligned nanofiber direction (cell major axis length) was significantly decreased, while cells still showed preferred orientation along the aligned nanofibers. On random nanofibers, MSCs with FAK-shRNA showed impaired cell spreading resulting in smaller cell area and higher circularity. Our study provides new data on how MSCs shape their morphologies on aligned and random nanofibrous cultures potentially via FAK-mediated mechanism. PMID:27040763

  15. Non-viral gene delivery regulated by stiffness of cell adhesion substrates

    NASA Astrophysics Data System (ADS)

    Kong, Hyun Joon; Liu, Jodi; Riddle, Kathryn; Matsumoto, Takuya; Leach, Kent; Mooney, David J.

    2005-06-01

    Non-viral gene vectors are commonly used for gene therapy owing to safety concerns with viral vectors. However, non-viral vectors are plagued by low levels of gene transfection and cellular expression. Current efforts to improve the efficiency of non-viral gene delivery are focused on manipulations of the delivery vector, whereas the influence of the cellular environment in DNA uptake is often ignored. The mechanical properties (for example, rigidity) of the substrate to which a cell adheres have been found to mediate many aspects of cell function including proliferation, migration and differentiation, and this suggests that the mechanics of the adhesion substrate may regulate a cell's ability to uptake exogeneous signalling molecules. In this report, we present a critical role for the rigidity of the cell adhesion substrate on the level of gene transfer and expression. The mechanism relates to material control over cell proliferation, and was investigated using a fluorescent resonance energy transfer (FRET) technique. This study provides a new material-based control point for non-viral gene therapy.

  16. Adhesive activity of Lu glycoproteins is regulated by interaction with spectrin

    SciTech Connect

    An, Xiuli; Gauthier, Emilie; Zhang, Xihui; Guo, Xinhua; Anstee, David; Mohandas, Narla; Anne Chasis, Joel

    2008-03-18

    The Lutheran (Lu) and Lu(v13) blood group glycoproteins function as receptors for extracellular matrix laminins. Lu and Lu(v13) are linked to the erythrocyte cytoskeleton through a direct interaction with spectrin. However, neither the molecular basis of the interaction nor its functional consequences have previously been delineated. In the present study, we defined the binding motifs of Lu and Lu(v13) on spectrin and identified a functional role for this interaction. We found that the cytoplasmic domains of both Lu and Lu(v13) bound to repeat 4 of the spectrin chain. The interaction of full-length spectrin dimer to Lu and Lu(v13) was inhibited by repeat 4 of {alpha}-spectrin. Further, resealing of this repeat peptide into erythrocytes led to weakened Lu-cytoskeleton interaction as demonstrated by increased detergent extractability of Lu. Importantly, disruption of the Lu-spectrin linkage was accompanied by enhanced cell adhesion to laminin. We conclude that the interaction of the Lu cytoplasmic tail with the cytoskeleton regulates its adhesive receptor function.

  17. KIF17 regulates RhoA-dependent actin remodeling at epithelial cell-cell adhesions.

    PubMed

    Acharya, Bipul R; Espenel, Cedric; Libanje, Fotine; Raingeaud, Joel; Morgan, Jessica; Jaulin, Fanny; Kreitzer, Geri

    2016-03-01

    The kinesin KIF17 localizes at microtubule plus-ends where it contributes to regulation of microtubule stabilization and epithelial polarization. We now show that KIF17 localizes at cell-cell adhesions and that KIF17 depletion inhibits accumulation of actin at the apical pole of cells grown in 3D organotypic cultures and alters the distribution of actin and E-cadherin in cells cultured in 2D on solid supports. Overexpression of full-length KIF17 constructs or truncation mutants containing the N-terminal motor domain resulted in accumulation of newly incorporated GFP-actin into junctional actin foci, cleared E-cadherin from cytoplasmic vesicles and stabilized cell-cell adhesions to challenge with calcium depletion. Expression of these KIF17 constructs also increased cellular levels of active RhoA, whereas active RhoA was diminished in KIF17-depleted cells. Inhibition of RhoA or its effector ROCK, or expression of LIMK1 kinase-dead or activated cofilin(S3A) inhibited KIF17-induced junctional actin accumulation. Interestingly, KIF17 activity toward actin depends on the motor domain but is independent of microtubule binding. Together, these data show that KIF17 can modify RhoA-GTPase signaling to influence junctional actin and the stability of the apical junctional complex of epithelial cells. PMID:26759174

  18. Anterior Gradient Protein-2 Is a Regulator of Cellular Adhesion in Prostate Cancer

    PubMed Central

    Chanda, Diptiman; Lee, Joo Hyoung; Sawant, Anandi; Hensel, Jonathan A.; Isayeva, Tatyana; Reilly, Stephanie D.; Siegal, Gene P.; Smith, Claire; Grizzle, William; Singh, Raj; Ponnazhagan, Selvarangan

    2014-01-01

    Anterior Gradient Protein (AGR-2) is reported to be over-expressed in many epithelial cancers and promotes metastasis. A clear-cut mechanism for its observed function(s) has not been previously identified. We found significant upregulation of AGR-2 expression in a bone metastatic prostate cancer cell line, PC3, following culturing in bone marrow-conditioned medium. Substantial AGR-2 expression was also confirmed in prostate cancer tissue specimens in patients with bone lesions. By developing stable clones of PC3 cells with varying levels of AGR-2 expression, we identified that abrogation of AGR-2 significantly reduced cellular attachment to fibronectin, collagen I, collagen IV, laminin I and fibrinogen. Loss of cellular adhesion was associated with sharp decrease in the expression of α4, α5, αV, β3 and β4 integrins. Failure to undergo apoptosis following detachment is a hallmark of epithelial cancer metastasis. The AGR-2-silenced PC3 cells showed higher resistance to Tumor necrosis factor-related apoptosis- inducing ligand (TRAIL) induced apoptosis in vitro. This observation was also supported by significantly reduced Caspase-3 expression in AGR-2-silenced PC3 cells, which is a key effector of both extrinsic and intrinsic death signaling pathways. These data suggest that AGR-2 influence prostate cancer metastasis by regulation of cellular adhesion and apoptosis. PMID:24587138

  19. Amigo Adhesion Protein Regulates Development of Neural Circuits in Zebrafish Brain*

    PubMed Central

    Zhao, Xiang; Kuja-Panula, Juha; Sundvik, Maria; Chen, Yu-Chia; Aho, Vilma; Peltola, Marjaana A.; Porkka-Heiskanen, Tarja; Panula, Pertti; Rauvala, Heikki

    2014-01-01

    The Amigo protein family consists of three transmembrane proteins characterized by six leucine-rich repeat domains and one immunoglobulin-like domain in their extracellular moieties. Previous in vitro studies have suggested a role as homophilic adhesion molecules in brain neurons, but the in vivo functions remain unknown. Here we have cloned all three zebrafish amigos and show that amigo1 is the predominant family member expressed during nervous system development in zebrafish. Knockdown of amigo1 expression using morpholino oligonucleotides impairs the formation of fasciculated tracts in early fiber scaffolds of brain. A similar defect in fiber tract development is caused by mRNA-mediated expression of the Amigo1 ectodomain that inhibits adhesion mediated by the full-length protein. Analysis of differentiated neural circuits reveals defects in the catecholaminergic system. At the behavioral level, the disturbed formation of neural circuitry is reflected in enhanced locomotor activity and in the inability of the larvae to perform normal escape responses. We suggest that Amigo1 is essential for the development of neural circuits of zebrafish, where its mechanism involves homophilic interactions within the developing fiber tracts and regulation of the Kv2.1 potassium channel to form functional neural circuitry that controls locomotion. PMID:24904058

  20. Adhesive activity of Lu glycoproteins is regulated by interaction with spectrin

    PubMed Central

    An, Xiuli; Gauthier, Emilie; Zhang, Xihui; Guo, Xinhua; Anstee, David J.; Mohandas, Narla

    2008-01-01

    The Lutheran (Lu) and Lu(v13) blood group glycoproteins function as receptors for extracellular matrix laminins. Lu and Lu(v13) are linked to the erythrocyte cytoskeleton through a direct interaction with spectrin. However, neither the molecular basis of the interaction nor its functional consequences have previously been delineated. In the present study, we defined the binding motifs of Lu and Lu(v13) on spectrin and identified a functional role for this interaction. We found that the cytoplasmic domains of both Lu and Lu(v13) bound to repeat 4 of the α spectrin chain. The interaction of full-length spectrin dimer to Lu and Lu(v13) was inhibited by repeat 4 of α-spectrin. Further, resealing of this repeat peptide into erythrocytes led to weakened Lu-cytoskeleton interaction as demonstrated by increased detergent extractability of Lu. Importantly, disruption of the Lu-spectrin linkage was accompanied by enhanced cell adhesion to laminin. We conclude that the interaction of the Lu cytoplasmic tail with the cytoskeleton regulates its adhesive receptor function. PMID:18815288

  1. In vivo evaluation of novel ketal-based oligosaccharides of hyaluronan micelles as multifunctional CD44 receptor-targeting and tumor pH-responsive carriers.

    PubMed

    Chen, Daquan; Sun, Jingfang; Sun, Kaoxiang; Liu, Wanhui; Wu, Zimei

    2016-05-01

    In this report, the oligosaccharides of hyaluronan (oHA)-histidine-menthone 1,2-glycerol ketal (MGK) (oHM) carried pH-sensitive MGK as hydrophobic moieties and oHA as the target of the CD44 receptor. The oHM could self-assemble, with a diameter of 65 nm. The cellular uptake, indicated by the fluorescent signals, was higher at 4 h. The ex vivo imaging indicated that micelles have a longer blood circulation, beyond 5 h. The fluorescence intensity of the micelles in the liver and spleen was much higher from 5 to 24 h. The CD44 receptor-targeting, indicated by the fluorescence signals of A549 and MDA-MB-231 group, were higher than those of the HepG2 and the control. PMID:25613026

  2. Junctional adhesion molecule-C (JAM-C) regulates polarized neutrophil transendothelial cell migration in vivo

    PubMed Central

    Woodfin, Abigail; Voisin, Mathieu-Benoit; Beyrau, Martina; Colom, Bartomeu; Caille, Dorothée; Diapouli, Frantzeska-Maria; Nash, Gerard B; Chavakis, Triantafyllos; Albelda, Steven M.; Rainger, G Ed; Meda, Paolo; Imhof, Beat A.; Nourshargh, Sussan

    2011-01-01

    Neutrophil migration into inflamed tissues is a fundamental component of innate immunity. A decisive step in this process is the polarised migration of blood neutrophils through endothelial cells (ECs) lining the venular lumen (transendothelial cell migration; TEM) in a luminal to abluminal direction. Using real-time confocal imaging we report that neutrophils can exhibit disrupted polarised TEM (“hesitant” and “reverse”) in vivo. These events were noted in inflammation following ischemia-reperfusion injury, characterised by reduced expression of junctional adhesion molecule C (JAM-C) from EC junctions, and were enhanced by EC JAM-C blockade or genetic deletion. The results identify JAM-C as a key regulator of polarised neutrophil TEM in vivo and suggest that reverse TEM neutrophils can contribute to dissemination of systemic inflammation. PMID:21706006

  3. L1 adhesion molecule on mouse leukocytes: regulation and involvement in endothelial cell binding.

    PubMed

    Hubbe, M; Kowitz, A; Schirrmacher, V; Schachner, M; Altevogt, P

    1993-11-01

    L1 is a cell surface glycoprotein of the immunoglobulin superfamily which was initially shown to mediate adhesion between neural cells. Recently we have reported that L1 is expressed by bone marrow cells and the majority of mature lymphocytes (Kowitz et al., Eur. J. Immunol. 1992. 22: 1199-1205). To analyze the function of L1 on leukocytes we studied its regulation following cell activation. In vitro activation of B lymphocytes with lipopolysaccharide or T lymphocytes with phorbol 12-myristate 13-acetate/Ca2+ ionophore, concanavalin A or anti-CD3 monoclonal antibody as well as in vivo activation of V beta 8+ T cells with staphylococcal enterotoxin B (SEB) revealed a down-regulation of L1 within 48 h. A rapid loss of L1 expression was seen when mouse neutrophils were activated with PMA alone. This rapid loss paralleled the shedding of L-selectin. We also studied a possible role of L1 in the binding of leukocytes to endothelial cells. ESb-MP lymphoma cells with a high expression of L1 (L1hi) could bind to bend3 endothelioma cells without prior activation with inflammatory cytokines. The interaction was inhibited by anti-L1 antibodies. In contrast, ESb-MP cells with low L1 expression (L1lo) were only marginally bound. Latex beads coated with affinity-isolated L1 antigen were also able to bind to the endothelioma cells in a specific fashion. The binding of ESb-MP lymphoma cells required Ca2+ and Mg2+ ions and was sensitive to cold temperature. Since the endothelioma cells did not express L1 the binding mechanism studied here is distinct from the established L1-L1 homotypic interaction. It is possible that the novel L1-mediated adhesion pathway involves an unidentified ligand and could play a role in leukocyte migration. PMID:8223869

  4. Identification and Isolation of Small CD44-Negative Mesenchymal Stem/Progenitor Cells From Human Bone Marrow Using Elutriation and Polychromatic Flow Cytometry

    PubMed Central

    Hall, Sean R.R.; Jiang, Yajuan; Leary, Elizabeth; Yavanian, Greg; Eminli, Sarah

    2013-01-01

    The method of isolation of bone marrow (BM) mesenchymal stem/stromal cells (MSCs) is a limiting factor in their study and therapeutic use. MSCs are typically expanded from BM cells selected on the basis of their adherence to plastic, which results in a heterogeneous population of cells. Prospective identification of the antigenic profile of the MSC population(s) in BM that gives rise to cells with MSC activity in vitro would allow the preparation of very pure populations of MSCs for research or clinical use. To address this issue, we used polychromatic flow cytometry and counterflow centrifugal elutriation to identify a phenotypically distinct population of mesenchymal stem/progenitor cells (MSPCs) within human BM. The MSPC activity resided within a population of rare, small CD45−CD73+CD90+CD105+ cells that lack CD44, an antigen that is highly expressed on culture-expanded MSCs. In culture, these MSPCs adhere to plastic, rapidly proliferate, and acquire CD44 expression. They form colony forming units-fibroblast and are able to differentiate into osteoblasts, chondrocytes, and adipocytes under defined in vitro conditions. Their acquired expression of CD44 can be partially downregulated by treatment with recombinant human granulocyte-colony stimulating factor, a response not found in BM-MSCs derived from conventional plastic adherence methods. These observations indicate that MSPCs within human BM are rare, small CD45−CD73+CD90+CD105+ cells that lack expression of CD44. These MSPCs give rise to MSCs that have phenotypic and functional properties that are distinct from those of BM-MSCs purified by plastic adherence. PMID:23847000

  5. Suppression of pancreatic tumor growth by targeted arsenic delivery with anti-CD44v6 single chain antibody conjugated nanoparticles.

    PubMed

    Qian, Chenchen; Wang, Yong; Chen, Yinting; Zeng, Linjuan; Zhang, Qiubo; Shuai, Xintao; Huang, Kaihong

    2013-08-01

    Arsenic trioxide (As2O3) is a promising anticancer agent for solid tumors. However, the high toxicity to normal tissues resulting from the lack of tumor specificity remains a huge challenge in its systemic application. Targeted vectors enabling drug delivery to specific cancer cells bring about great potential for better therapeutic efficacy whereas low side effects in cancer treatments. Our previous work has demonstrated that the anti-CD44v6 single chain variable fragment (scFv(CD44v6)) screened out from the human phage-displayed scFv library possesses high specificity and affinity to membrane antigen CD44v6 over-expressing in a subset of epithelium-derived cancers, such as pancreatic, hepatocellular, colorectal and gastric cancers. Herein, a maleimide-functionalized amphiphilic diblock copolymer of poly (ethylene glycol) and poly (D, L-lactide) (mal-PEG-PDLLA) was synthesized and assembled to vesicles with arsenite ion (As) encapsulated in their cores (As-NPs). Conjugation of scFv(CD44v6) with mal-PEG-PDLLA (scFv-As-NPs) enabled more efficient delivery of As and exhibited higher cytotoxic activity than non-targeted ones (As-NPs) in human pancreatic cancer cells PANC-1. Furthermore, the targeted delivery of As induced more significant gene suppression in terms of the expression of anti-apoptotic Bcl-2 protein. Consequently, the expression level of cleaved caspase-3 which is a molecular indicator of cell apoptosis was remarkably elevated. In animal tests, scFv-As-NPs were found to greatly increase accumulation of drug in tumor site and potentiate the efficacy of As in inhibiting tumor growth owing to the enhanced cell apoptosis. These results imply that our tumor specific nanocarriers provide a highly efficient and safe platform for pancreatic cancer therapy. PMID:23721794

  6. Pregnancy-associated plasma protein A up-regulated by progesterone promotes adhesion and proliferation of trophoblastic cells.

    PubMed

    Wang, Jiao; Liu, Shuai; Qin, Hua-Min; Zhao, Yue; Wang, Xiao-Qi; Yan, Qiu

    2014-01-01

    Embryo implantation and development is a complex biological process for the establishment of the successful pregnancy. Progesterone is a critical factor in the regulation of embryo adhesion to uterine endometrium and proliferation. Although it has been reported that pregnancy-associated plasma protein A (PAPPA) is increased in pregnant women, the relationship between progesterone and PAPPA, and the effects of PAPPA on embryo adhesion and proliferation are still not clear. The present results showed that the serum level of progesterone and PAPPA was closely correlated by ELISA assay (p<0.01). PAPPA was detected in the villi of early embryo by RT-PCR, Western blot, immunohistochemistry and immunofluorescent staining. Moreover, PAPPA was significantly up-regulated by progesterone in trophoblastic (JAR) cells by Real-time PCR and ELISA assay (p<0.01); while the expression was decreased by the progesterone receptor inhibitor RU486. The down-regulation of PAPPA by siRNA transfection or up-regulation of PAPPA by progesterone treatment significantly decreased or increased the adhesion rate of trophoblastic cells to human uterine epithelial cell lines (RL95-2 and HEC-1A), respectively (p<0.01), as well as the proliferation of trophoblastic cells. In conclusion, PAPPA is up-regulated by progesterone, which promotes the adhesion and proliferation potential of trophoblastic cells. PMID:24817938

  7. Mannosylation Allows for Synergic (CD44/C-Type Lectin) Uptake of Hyaluronic Acid Nanoparticles in Dendritic Cells, but Only upon Correct Ligand Presentation.

    PubMed

    Gennari, Arianna; Pelliccia, Maria; Donno, Roberto; Kimber, Ian; Tirelli, Nicola

    2016-04-01

    The selective targeting of dendritic cells (DCs) can lead to more efficacious vaccines. Here, materials have been designed for a synergic DC targeting: interacting with CD44 through the use of hyaluronic acid (HA), and with mannose-binding lectins (typical DC pattern recognition receptors) through HA mannosylation. Negatively charged, HA-displaying nanoparticles are produced via polyelectrolyte complexation of (mannosylated) HA and high- or low- molecular-weight chitosan (CS, 36 and 656 kDa). Using CS36, HA is better exposed and the particles have a higher affinity for HA receptors; this means a higher number of receptors clustered around each particle and, due to the rather limited CD44 availability, an overall lower uptake per cell. Employing Langerhans-like XS106 cells, all particles show negligible toxicity or inflammatory activation. The cellular uptake kinetics are qualitatively similar to other leukocytic models and thus considered to be CD44-dominated; the uptake increases with increasing HA mannosylation and with the use of adjuvants (LPS, mannan) for CS36/HA but not for CS656//HA particles; this indicates that the interactions with mannose-binding receptors requires a correct ligand presentation, and only in that case can they be enhanced by appropriate adjuvants. In summary, mannose-binding receptors can be used to enhance the internalization of HA-based carriers, although this positive synergy depends on the mode of ligand presentation. PMID:26865006

  8. Registered report: the microRNA miR-34a inhibits prostate cancer stem cells and metastasis by directly repressing CD44.

    PubMed

    Li, Jia; Lam, Matthew

    2015-01-01

    The Reproducibility Project: Cancer Biology seeks to address growing concerns about reproducibility in scientific research by conducting replications of selected experiments 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 'The microRNA miR-34a inhibits prostate cancer stem cells and metastasis by directly repressing CD44' by Liu and colleagues published in Nature Medicine in 2011 (Liu et al., 2011). Liu and colleagues first demonstrated that miR-34a levels were reduced in CD44+ prostate cancer cells (Figure 1B). They then showed that xenograft tumors from cells expressing exogenous miR-34a were smaller in size than control tumors (Supplemental Figure 5C). Tumors with exogenous miR-34a showed reduced levels of CD44 expression (Figure 4A), and mutation of two putative miR-34a binding sites in the CD33 3' UTR partially abrogated signal repression in a luciferase assay (Figure 4D). 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 by eLife. PMID:26231042

  9. Registered report: the microRNA miR-34a inhibits prostate cancer stem cells and metastasis by directly repressing CD44

    PubMed Central

    Li, Jia; Lam, Matthew

    2015-01-01

    The Reproducibility Project: Cancer Biology seeks to address growing concerns about reproducibility in scientific research by conducting replications of selected experiments 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 ‘The microRNA miR-34a inhibits prostate cancer stem cells and metastasis by directly repressing CD44’ by Liu and colleagues published in Nature Medicine in 2011 (Liu et al., 2011). Liu and colleagues first demonstrated that miR-34a levels were reduced in CD44+ prostate cancer cells (Figure 1B). They then showed that xenograft tumors from cells expressing exogenous miR-34a were smaller in size than control tumors (Supplemental Figure 5C). Tumors with exogenous miR-34a showed reduced levels of CD44 expression (Figure 4A), and mutation of two putative miR-34a binding sites in the CD33 3′ UTR partially abrogated signal repression in a luciferase assay (Figure 4D). 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 by eLife. DOI: http://dx.doi.org/10.7554/eLife.06434.001 PMID:26231042

  10. Isolation and characterisation of antibodies which specifically recognise the peptide encoded by exon 7 (v2) of the human CD44 gene

    PubMed Central

    Borgya, A; Woodman, A; Sugiyama, M; Donié, F; Kopetzki, E; Matsumura, Y; Tarin, D

    1995-01-01

    Aims—Exon 7 of the human CD44 gene is overexpressed in many commonly occurring carcinomas. The aim of the study was to explore the diagnostic and therapeutic potential of this frequent abnormality. Methods—A new monoclonal antibody (mAb, M-23.6.1) and a polyclonal antibody (pAb,S-6127) to the corresponding antigen were raised by immunising mice and sheep, respectively, with a specially constructed fusion protein HIV2 (gp32)-CD44 exon 7. Results—Characterisation of mAb, M-23.6.1 by ELISA, western blotting, immunocytochemistry, and FACS analysis confirmed that it specifically recognises an epitope in the region between amino acids 19 and 33 of the peptide encoded by this exon. Western blotting experiments with two cell lines, RT112 and ZR75-1, known from RT-PCR data to be overtranscribing the exon, yielded a monospecific band of approximately 220 kDa, and immunocytochemistry showed discrete membrane staining on the same cell lines. Fluorescent antibody cell sorting (FACS) revealed binding to greater than 90% of the cells of each of these lines. Specificity of recognition of the antigen was shown by inhibition of the precise immunoreactivity typically seen in ELISA and Western blots, by pre-incubation with synthetic exon 7 peptide or fragments of it. Conclusions—The new antibodies will be useful tools for the further analysis of abnormal CD44 isoforms and their clinical implications. Images PMID:16696015

  11. Functional interactions of the cystine/glutamate antiporter, CD44v and MUC1-C oncoprotein in triple-negative breast cancer cells

    PubMed Central

    Hasegawa, Masanori; Takahashi, Hidekazu; Rajabi, Hasan; Alam, Maroof; Suzuki, Yozo; Yin, Li; Tagde, Ashujit; Maeda, Takahiro; Hiraki, Masayuki; Sukhatme, Vikas P.; Kufe, Donald

    2016-01-01

    The xCT light chain of the cystine/glutamate transporter (system XC−) is of importance for the survival of triple-negative breast cancer (TNBC) cells. The MUC1-C transmembrane oncoprotein is aberrantly overexpressed in TNBC and, like xCT, has been linked to maintaining glutathione (GSH) levels and redox balance. However, there is no known interaction between MUC1-C and xCT. Here we show that silencing MUC1-C is associated with decreases in xCT expression in TNBC cells. The results demonstrate that MUC1-C forms a complex with xCT and the CD44 variant (CD44v), which interacts with xCT and thereby controls GSH levels. MUC1-C binds directly with CD44v and in turn promotes stability of xCT in the cell membrane. The interaction between MUC1-C and xCT is further supported by the demonstration that targeting xCT with silencing or the inhibitor sulfasalazine suppresses MUC1 gene transcription by increasing histone and DNA methylation on the MUC1 promoter. In terms of the functional significance of the MUC1-C/xCT interaction, we show that MUC1-C protects against treatment with erastin, an inhibitor of XC− and inducer of ferroptosis, a form of non-apoptotic cell death. These findings indicate that targeting this novel MUC1-C/xCT pathway could represent a potential therapeutic approach for promoting TNBC cell death. PMID:26930718

  12. Nav1.5 regulates breast tumor growth and metastatic dissemination in vivo

    PubMed Central

    Nelson, Michaela; Yang, Ming; Millican-Slater, Rebecca; Brackenbury, William J.

    2015-01-01

    Voltage-gated Na+ channels (VGSCs) mediate action potential firing and regulate adhesion and migration in excitable cells. VGSCs are also expressed in cancer cells. In metastatic breast cancer (BCa) cells, the Nav1.5 α subunit potentiates migration and invasion. In addition, the VGSC-inhibiting antiepileptic drug phenytoin inhibits tumor growth and metastasis. However, the functional activity of Nav1.5 and its specific contribution to tumor progression in vivo has not been delineated. Here, we found that Nav1.5 is up-regulated at the protein level in BCa compared with matched normal breast tissue. Na+ current, reversibly blocked by tetrodotoxin, was retained in cancer cells in tumor tissue slices, thus directly confirming functional VGSC activity in vivo. Stable down-regulation of Nav1.5 expression significantly reduced tumor growth, local invasion into surrounding tissue, and metastasis to liver, lungs and spleen in an orthotopic BCa model. Nav1.5 down-regulation had no effect on cell proliferation or angiogenesis within the in tumors, but increased apoptosis. In vitro, Nav1.5 down-regulation altered cell morphology and reduced CD44 expression, suggesting that VGSC activity may regulate cellular invasion via the CD44-src-cortactin signaling axis. We conclude that Nav1.5 is functionally active in cancer cells in breast tumors, enhancing growth and metastatic dissemination. These findings support the notion that compounds targeting Nav1.5 may be useful for reducing metastasis. PMID:26452220

  13. HAb18G/CD147 Promotes pSTAT3-Mediated Pancreatic Cancer Development via CD44s †, ‡

    PubMed Central

    Li, Ling; Tang, Wenhua; Wu, Xiaoqing; Karnak, David; Meng, Xiaojie; Thompson, Rachel; Hao, Xinbao; Li, Yongmin; Qiao, Xiaotan T.; Lin, Jiayuh; Fuchs, James; Simeone, Diane M.; Chen, Zhi-Nan; Lawrence, Theodore S.; Xu, Liang

    2013-01-01

    Purpose STAT3 plays a critical role in initiation and progression of pancreatic cancer. However, therapeutically targeting STAT3 is failure in clinic. We previously identified HAb18G/CD147 as an effective target for cancer treatment. In this study, we aimed to investigate potential role of HAb18G/CD147 in STAT3-involved pancreatic tumorigenesis in vitro and in vivo. Experimental Design The expression of HAb18G/CD147, pSTAT3 and CD44s were determined in tissue microarrays. The tumorigenic function and molecular signaling mechanism of HAb18G/CD147 was assessed by in vitro cellular and clonogenic growth, reporter assay, immunoblot, immunofluorescence staining, immunoprecipitation, and in vivo tumor formationusing loss or gain-of-function strategies. Results Highly expressed HAb18G/CD147 promoted cellular and clonogenic growth in vitro and tumorigenicity in vivo. CyPA, a ligand of CD147, stimulated STAT3 phosphorylation and its downstream genes cyclin D1/survivin through HAb18G/CD147 dependent mechanisms. HAb18G/CD147 was associated and co-localized with cancer stem cell marker CD44s in lipid rafts. The inhibitors of STAT3 and survivin, as well as CD44s neutralizing antibodies suppressed the HAb18G/CD147-induced cell growth. High HAb18G/CD147 expression in pancreatic cancer was significantly correlated with the poor tumor differentiation, and the high co-expression of HAb18G/CD147-CD44s-STAT3 associated with poor survival of patients with pancreatic cancer. Conclusions We identified HAb18G/CD147 as a novel upstream activator of STAT3 via interacts with CD44s and plays a critical role in the development of pancreatic cancer. The data suggest HAb18G/CD147 could be a promising therapeutic target for highly aggressive pancreatic cancer and a surrogate marker in the STAT3-targeted molecular therapies. PMID:24132924

  14. Evaluation of a novel type of imaging probe based on a recombinant bivalent mini-antibody construct for detection of CD44v6-expressing squamous cell carcinoma

    PubMed Central

    HAYLOCK, ANNA-KARIN; SPIEGELBERG, DIANA; MORTENSEN, ANJA C.; SELVARAJU, RAM K.; NILVEBRANT, JOHAN; ERIKSSON, OLOF; TOLMACHEV, VLADIMIR; NESTOR, MARIKA V.

    2016-01-01

    We have developed the CD44v6-targeting human bivalent antibody fragment AbD19384, an engineered recombinant human bivalent Fab antibody formed via dimerization of dHLX (synthetic double helix loop helix motif) domains, for potential use in antibody-based molecular imaging of squamous cell carcinoma in the head and neck region. This is a unique construct that has, to the best of our knowledge, never been assessed for molecular imaging in vivo before. The objective of the present study was to evaluate for the first time the in vitro and in vivo binding properties of radio-iodinated AbD19384, and to assess its utility as a targeting agent for molecular imaging of CD44v6-expressing tumors. Antigen specificity and binding properties were assessed in vitro. In vivo specificity and biodistribution of 125I-AbD19384 were next evaluated in tumor-bearing mice using a dual-tumor setup. Finally, AbD19384 was labeled with 124I, and its imaging properties were assessed by small animal PET/CT in tumor bearing mice, and compared with 2-deoxy-2-[18F]fluoro-D-glucose (18F-FDG). In vitro studies demonstrated CD44v6-specific binding with slow off-rate for AbD19384. A favorable biodis-tribution profile was seen in vivo, with tumor-specific uptake. Small animal PET/CT images of 124I-AbD19384 supported the results through clearly visible high CD44v6-expressing tumors and faintly visible low expressing tumors, with superior imaging properties compared to 18F-FDG. Tumor-to-blood ratios increased with time for the conjugate (assessed up to 72 h p.i.), although 48 h p.i. proved best for imaging. Biodistribution and small-animal PET studies demonstrated that the recombinant Fab-dHLX construct AbD19384 is a promising tracer for imaging of CD44v6 antigen expression in vivo, with the future aim to be used for individualized diagnosis and early detection of squamous cell carcinomas in the head and neck region. Furthermore, this proof-of-concept research established the feasibility of using

  15. Src Kinase Determines the Dynamic Exchange of the Docking Protein NEDD9 (Neural Precursor Cell Expressed Developmentally Down-regulated Gene 9) at Focal Adhesions*

    PubMed Central

    Bradbury, Peta; Bach, Cuc T.; Paul, Andre; O'Neill, Geraldine M.

    2014-01-01

    Dynamic exchange of molecules between the cytoplasm and integrin-based focal adhesions provides a rapid response system for modulating cell adhesion. Increased residency time of molecules that regulate adhesion turnover contributes to adhesion stability, ultimately determining migration speed across two-dimensional surfaces. In the present study we test the role of Src kinase in regulating dynamic exchange of the focal adhesion protein NEDD9/HEF1/Cas-L. Using either chemical inhibition or fibroblasts genetically null for Src together with fluorescence recovery after photobleaching (FRAP), we find that Src significantly reduces NEDD9 exchange at focal adhesions. Analysis of NEDD9 mutant constructs with the two major Src-interacting domains disabled revealed the greatest effects were due to the NEDD9 SH2 binding domain. This correlated with a significant change in two-dimensional migratory speed. Given the emerging role of NEDD9 as a regulator of focal adhesion stability, the time of NEDD9 association at the focal adhesions is key in modulating rates of migration and invasion. Our study suggests that Src kinase activity determines NEDD9 exchange at focal adhesions and may similarly modulate other focal adhesion-targeted Src substrates to regulate cell migration. PMID:25059660

  16. Up-regulation of the homophilic adhesion molecule sidekick-1 in podocytes contributes to glomerulosclerosis.

    PubMed

    Kaufman, Lewis; Potla, Uma; Coleman, Sarah; Dikiy, Stanislav; Hata, Yutaka; Kurihara, Hidetake; He, John C; D'Agati, Vivette D; Klotman, Paul E

    2010-08-13

    Focal segmental glomerulosclerosis (FSGS) is a leading cause of nephrotic syndrome and end-stage renal disease worldwide. Although the mechanisms underlying this important disease are poorly understood, the glomerular podocyte clearly plays a central role in disease pathogenesis. In the current work, we demonstrate that the homophilic adhesion molecule sidekick-1 (sdk-1) is up-regulated in podocytes in FSGS both in rodent models and in human kidney biopsy samples. Transgenic mice that have podocyte-specific overexpression of sdk-1 develop gradually progressive heavy proteinuria and severe FSGS. We also show that sdk-1 associates with the slit diaphragm linker protein MAGI-1, which is already known to interact with several critical podocyte proteins including synaptopodin, alpha-actinin-4, nephrin, JAM4, and beta-catenin. This interaction is mediated through a direct interaction between the carboxyl terminus of sdk-1 and specific PDZ domains of MAGI-1. In vitro expression of sdk-1 enables a dramatic recruitment of MAGI-1 to the cell membrane. Furthermore, a truncated version of sdk-1 that is unable to bind to MAGI-1 does not induce podocyte dysfunction when overexpressed. We conclude that the up-regulation of sdk-1 in podocytes is an important pathogenic factor in FSGS and that the mechanism involves disruption of the actin cytoskeleton possibly via alterations in MAGI-1 function. PMID:20562105

  17. Regulation of Epithelial-Mesenchymal Transition in Breast Cancer Cells by Cell Contact and Adhesion

    PubMed Central

    Cichon, Magdalena A; Nelson, Celeste M; Radisky, Derek C

    2015-01-01

    Epithelial-mesenchymal transition (EMT) is a physiological program that is activated during cancer cell invasion and metastasis. We show here that EMT-related processes are linked to a broad and conserved program of transcriptional alterations that are influenced by cell contact and adhesion. Using cultured human breast cancer and mouse mammary epithelial cells, we find that reduced cell density, conditions under which cell contact is reduced, leads to reduced expression of genes associated with mammary epithelial cell differentiation and increased expression of genes associated with breast cancer. We further find that treatment of cells with matrix metalloproteinase-3 (MMP-3), an inducer of EMT, interrupts a defined subset of cell contact-regulated genes, including genes encoding a variety of RNA splicing proteins known to regulate the expression of Rac1b, an activated splice isoform of Rac1 known to be a key mediator of MMP-3-induced EMT in breast, lung, and pancreas. These results provide new insights into how MMPs act in cancer progression and how loss of cell–cell interactions is a key step in the earliest stages of cancer development. PMID:25698877

  18. Antigenic variation of pilin regulates adhesion of Neisseria meningitidis to human epithelial cells.

    PubMed

    Nassif, X; Lowy, J; Stenberg, P; O'Gaora, P; Ganji, A; So, M

    1993-05-01

    Pili have been shown to play an essential role in the adhesion of Neisseria meningitidis to epithelial cells. However, among piliated strains, both inter- and intrastrain variability exist with respect to their degree of adhesion to epithelial cells in vitro (Virji et al., 1992). This suggests that factors other than the presence of pili per se are involved in this process. The N. meningitidis pilin subunit undergoes extensive antigenic variation. Piliated low- and high-adhesive derivatives of the same N. meningitidis strain were selected and the nucleotide sequence of the pilin gene expressed in each was determined. The highly adhesive derivatives had the same pilin sequence. The alleles encoding the pilin subunit of the low-adhesive derivatives were completely different from the one found in the high-adhesive isolates. Using polyclonal antibodies raised against one hyperadhesive variant, it was confirmed that the low-adhesive piliated derivatives expressed pilin variants antigenically different from the highly adhesive strains. The role of antigenic variation in the adhesive process of N. meningitidis was confirmed by performing allelic exchanges of the pilE locus between low- and high-adhesive isolates. Antigenic variation has been considered a means by which virulent bacteria evade the host immune system. This work provides genetic proof that a bacterial pathogen, N. meningitidis, can use antigenic variation to modulate their degree of virulence. PMID:8332064

  19. Neural Cell Adhesion Molecule NrCAM Regulates Semaphorin 3F-Induced Dendritic Spine Remodeling

    PubMed Central

    Demyanenko, Galina P.; Mohan, Vishwa; Zhang, Xuying; Brennaman, Leann H.; Dharbal, Katherine E.S.; Tran, Tracy S.; Manis, Paul B.

    2014-01-01

    Neuron-glial related cell adhesion molecule (NrCAM) is a regulator of axon growth and repellent guidance, and has been implicated in autism spectrum disorders. Here a novel postsynaptic role for NrCAM in Semaphorin3F (Sema3F)-induced dendritic spine remodeling was identified in pyramidal neurons of the primary visual cortex (V1). NrCAM localized to dendritic spines of star pyramidal cells in postnatal V1, where it was coexpressed with Sema3F. NrCAM deletion in mice resulted in elevated spine densities on apical dendrites of star pyramidal cells at both postnatal and adult stages, and electron microscopy revealed increased numbers of asymmetric synapses in layer 4 of V1. Whole-cell recordings in cortical slices from NrCAM-null mice revealed increased frequency of mEPSCs in star pyramidal neurons. Recombinant Sema3F-Fc protein induced spine retraction on apical dendrites of wild-type, but not NrCAM-null cortical neurons in culture, while re-expression of NrCAM rescued the spine retraction response. NrCAM formed a complex in brain with Sema3F receptor subunits Neuropilin-2 (Npn-2) and PlexinA3 (PlexA3) through an Npn-2-binding sequence (TARNER) in the extracellular Ig1 domain. A trans heterozygous genetic interaction test demonstrated that Sema3F and NrCAM pathways interacted in vivo to regulate spine density in star pyramidal neurons. These findings reveal NrCAM as a novel postnatal regulator of dendritic spine density in cortical pyramidal neurons, and an integral component of the Sema3F receptor complex. The results implicate NrCAM as a contributor to excitatory/inhibitory balance in neocortical circuits. PMID:25143608

  20. Regulated Intramembrane Proteolysis and Degradation of Murine Epithelial Cell Adhesion Molecule mEpCAM

    PubMed Central

    Hachmeister, Matthias; Bobowski, Karolina D.; Hogl, Sebastian; Dislich, Bastian; Fukumori, Akio; Eggert, Carola; Mack, Brigitte; Kremling, Heidi; Sarrach, Sannia; Coscia, Fabian; Zimmermann, Wolfgang; Steiner, Harald; Lichtenthaler, Stefan F.; Gires, Olivier

    2013-01-01

    Epithelial cell adhesion molecule EpCAM is a transmembrane glycoprotein, which is highly and frequently expressed in carcinomas and (cancer-)stem cells, and which plays an important role in the regulation of stem cell pluripotency. We show here that murine EpCAM (mEpCAM) is subject to regulated intramembrane proteolysis in various cells including embryonic stem cells and teratocarcinomas. As shown with ectopically expressed EpCAM variants, cleavages occur at α-, β-, γ-, and ε-sites to generate soluble ectodomains, soluble Aβ-like-, and intracellular fragments termed mEpEX, mEp-β, and mEpICD, respectively. Proteolytic sites in the extracellular part of mEpCAM were mapped using mass spectrometry and represent cleavages at the α- and β-sites by metalloproteases and the b-secretase BACE1, respectively. Resulting C-terminal fragments (CTF) are further processed to soluble Aβ-like fragments mEp-β and cytoplasmic mEpICD variants by the g-secretase complex. Noteworthy, cytoplasmic mEpICD fragments were subject to efficient degradation in a proteasome-dependent manner. In addition the γ-secretase complex dependent cleavage of EpCAM CTF liberates different EpICDs with different stabilities towards proteasomal degradation. Generation of CTF and EpICD fragments and the degradation of hEpICD via the proteasome were similarly demonstrated for the human EpCAM ortholog. Additional EpCAM orthologs have been unequivocally identified in silico in 52 species. Sequence comparisons across species disclosed highest homology of BACE1 cleavage sites and in presenilin-dependent γ-cleavage sites, whereas strongest heterogeneity was observed in metalloprotease cleavage sites. In summary, EpCAM is a highly conserved protein present in fishes, amphibians, reptiles, birds, marsupials, and placental mammals, and is subject to shedding, γ-secretase-dependent regulated intramembrane proteolysis, and proteasome-mediated degradation. PMID:24009667

  1. Regulation of T-lymphocyte motility, adhesion and de-adhesion by a cell surface mechanism directed by low density lipoprotein receptor-related protein 1 and endogenous thrombospondin-1

    PubMed Central

    Talme, Toomas; Bergdahl, Eva; Sundqvist, Karl-Gösta

    2014-01-01

    T lymphocytes are highly motile and constantly reposition themselves between a free-floating vascular state, transient adhesion and migration in tissues. The regulation behind this unique dynamic behaviour remains unclear. Here we show that T cells have a cell surface mechanism for integrated regulation of motility and adhesion and that integrin ligands and CXCL12/SDF-1 influence motility and adhesion through this mechanism. Targeting cell surface-expressed low-density lipoprotein receptor-related protein 1 (LRP1) with an antibody, or blocking transport of LRP1 to the cell surface, perturbed the cell surface distribution of endogenous thrombospondin-1 (TSP-1) while inhibiting motility and potentiating cytoplasmic spreading on intercellular adhesion molecule 1 (ICAM-1) and fibronectin. Integrin ligands and CXCL12 stimulated motility and enhanced cell surface expression of LRP1, intact TSP-1 and a 130 000 MW TSP-1 fragment while preventing formation of a de-adhesion-coupled 110 000 MW TSP-1 fragment. The appearance of the 130 000 MW TSP-1 fragment was inhibited by the antibody that targeted LRP1 expression, inhibited motility and enhanced spreading. The TSP-1 binding site in the LRP1-associated protein, calreticulin, stimulated adhesion to ICAM-1 through intact TSP-1 and CD47. Shear flow enhanced cell surface expression of intact TSP-1. Hence, chemokines and integrin ligands up-regulate a dominant motogenic pathway through LRP1 and TSP-1 cleavage and activate an associated adhesion pathway through the LRP1–calreticulin complex, intact TSP-1 and CD47. This regulation of T-cell motility and adhesion makes pro-adhesive stimuli favour motile responses, which may explain why T cells prioritize movement before permanent adhesion. PMID:24877199

  2. PBRM1 Regulates the Expression of Genes Involved in Metabolism and Cell Adhesion in Renal Clear Cell Carcinoma

    PubMed Central

    Chowdhury, Basudev; Porter, Elizabeth G.; Stewart, Jane C.; Ferreira, Christina R.; Schipma, Matthew J.; Dykhuizen, Emily C.

    2016-01-01

    Polybromo-1 (PBRM1) is a component of the PBAF (Polybromo-associated-BRG1- or BRM-associated factors) chromatin remodeling complex and is the second most frequently mutated gene in clear-cell renal cell Carcinoma (ccRCC). Mutation of PBRM1 is believed to be an early event in carcinogenesis, however its function as a tumor suppressor is not understood. In this study, we have employed Next Generation Sequencing to profile the differentially expressed genes upon PBRM1 re-expression in a cellular model of ccRCC. PBRM1 re-expression led to upregulation of genes involved in cellular adhesion, carbohydrate metabolism, apoptotic process and response to hypoxia, and a downregulation of genes involved in different stages of cell division. The decrease in cellular proliferation upon PBRM1 re-expression was confirmed, validating the functional role of PBRM1 as a tumor suppressor in a cell-based model. In addition, we identified a role for PBRM1 in regulating metabolic pathways known to be important for driving ccRCC, including the regulation of hypoxia response genes, PI3K signaling, glucose uptake, and cholesterol homeostasis. Of particular novelty is the identification of cell adhesion as a major downstream process uniquely regulated by PBRM1 expression. Cytoskeletal reorganization was induced upon PBRM1 reexpression as evidenced from the increase in the number of cells displaying cortical actin, a hallmark of epithelial cells. Genes involved in cell adhesion featured prominently in our transcriptional dataset and overlapped with genes uniquely regulated by PBRM1 in clinical specimens of ccRCC. Genes involved in cell adhesion serve as tumor suppressor and maybe involved in inhibiting cell migration. Here we report for the first time genes linked to cell adhesion serve as downstream targets of PBRM1, and hope to lay the foundation of future studies focusing on the role of chromatin remodelers in bringing about these alterations during malignancies. PMID:27100670

  3. The self-renewal of mouse embryonic stem cells is regulated by cell–substratum adhesion and cell spreading☆

    PubMed Central

    Murray, Patricia; Prewitz, Marina; Hopp, Isabel; Wells, Nicola; Zhang, Haifei; Cooper, Andrew; Parry, Kristina L.; Short, Robert; Antoine, Daniel J.; Edgar, David

    2013-01-01

    Mouse embryonic stem cells (mESCs) undergo self-renewal in the presence of the cytokine, leukaemia inhibitory factor (LIF). Following LIF withdrawal, mESCs differentiate, and this is accompanied by an increase in cell–substratum adhesion and cell spreading. The purpose of this study was to investigate the relationship between cell spreading and mESC differentiation. Using E14 and R1 mESC lines, we have restricted cell spreading in the absence of LIF by either culturing mESCs on chemically defined, weakly adhesive biomaterial substrates, or by manipulating the cytoskeleton. We demonstrate that by restricting the degree of spreading by either method, mESCs can be maintained in an undifferentiated and pluripotent state. Under these conditions, self-renewal occurs without the need for LIF and is independent of nuclear translocation of tyrosine-phosphorylated STAT3 or β-catenin, which have previously been implicated in self-renewal. We also demonstrate that the effect of restricted cell spreading on mESC self-renewal is not mediated by increased intercellular adhesion, as evidenced by the observations that inhibition of mESC adhesion using a function blocking anti E-cadherin antibody or siRNA do not promote differentiation. These results show that mESC spreading and differentiation are regulated both by LIF and by cell–substratum adhesion, consistent with the hypothesis that cell spreading is the common intermediate step in the regulation of mESC differentiation by either LIF or cell–substratum adhesion. PMID:23871934

  4. ΔNp63α Transcriptionally Regulates the Expression of CTEN That Is Associated with Prostate Cell Adhesion

    PubMed Central

    Chen, Ya-Chi; Lo, Su Hao; Liao, Yi-Chun

    2016-01-01

    p63 is a member of the p53 transcription factor family and a linchpin of epithelial development and homeostasis. p63 drives the expression of many target genes involved in cell survival, adhesion, migration and cancer. In this study, we identify C-terminal tensin-like (CTEN) molecule as a downstream target of ΔNp63α, the predominant p63 isoform expressed in epithelium. CTEN belongs to the tensin family and is mainly localized to focal adhesions, which mediate many biological events such as cell adhesion, migration, proliferation and gene expression. Our study demonstrate that ΔNp63 and CTEN are both highly expressed in normal prostate epithelial cells and are down-regulated in prostate cancer. In addition, reduced expression of CTEN and ΔNp63 is correlated with prostate cancer progression from primary tumors to metastatic lesions. Silencing of ΔNp63 leads to decreased mRNA and protein levels of CTEN. ΔNp63α induces transcriptional activity of the CTEN promoter and a 140-bp fragment upstream of the transcription initiation site is the minimal promoter region required for activation. A putative binding site for p63 is located between -61 and -36 within the CTEN promoter and mutations of the critical nucleotides in this region abolish ΔNp63α-induced promoter activity. The direct interaction of ΔNp63α with the CTEN promoter was demonstrated using a chromatin immunoprecipitation (ChIP) assay. Moreover, impaired cell adhesion caused by ΔNp63α depletion is rescued by over-expression of CTEN, suggesting that CTEN is a downstream effector of ΔNp63α-mediated cell adhesion. In summary, our findings demonstrate that ΔNp63α functions as a trans-activation factor of CTEN promoter and regulates cell adhesion through modulating CTEN. Our study further contributes to the potential regulatory mechanisms of CTEN in prostate cancer progression. PMID:26784942

  5. Vascular Cell Adhesion Molecule-1 Expression and Signaling During Disease: Regulation by Reactive Oxygen Species and Antioxidants

    PubMed Central

    Marchese, Michelle E.; Abdala-Valencia, Hiam

    2011-01-01

    Abstract The endothelium is immunoregulatory in that inhibiting the function of vascular adhesion molecules blocks leukocyte recruitment and thus tissue inflammation. The function of endothelial cells during leukocyte recruitment is regulated by reactive oxygen species (ROS) and antioxidants. In inflammatory sites and lymph nodes, the endothelium is stimulated to express adhesion molecules that mediate leukocyte binding. Upon leukocyte binding, these adhesion molecules activate endothelial cell signal transduction that then alters endothelial cell shape for the opening of passageways through which leukocytes can migrate. If the stimulation of this opening is blocked, inflammation is blocked. In this review, we focus on the endothelial cell adhesion molecule, vascular cell adhesion molecule-1 (VCAM-1). Expression of VCAM-1 is induced on endothelial cells during inflammatory diseases by several mediators, including ROS. Then, VCAM-1 on the endothelium functions as both a scaffold for leukocyte migration and a trigger of endothelial signaling through NADPH oxidase-generated ROS. These ROS induce signals for the opening of intercellular passageways through which leukocytes migrate. In several inflammatory diseases, inflammation is blocked by inhibition of leukocyte binding to VCAM-1 or by inhibition of VCAM-1 signal transduction. VCAM-1 signal transduction and VCAM-1-dependent inflammation are blocked by antioxidants. Thus, VCAM-1 signaling is a target for intervention by pharmacological agents and by antioxidants during inflammatory diseases. This review discusses ROS and antioxidant functions during activation of VCAM-1 expression and VCAM-1 signaling in inflammatory diseases. Antioxid. Redox Signal. 15, 1607–1638. PMID:21050132

  6. p120 catenin regulates lamellipodial dynamics and cell adhesion in cooperation with cortactin

    PubMed Central

    Boguslavsky, Shlomit; Grosheva, Inna; Landau, Elad; Shtutman, Michael; Cohen, Miriam; Arnold, Katya; Feinstein, Elena; Geiger, Benjamin; Bershadsky, Alexander

    2007-01-01

    The armadillo-family protein, p120 catenin (p120), binds to the juxtamembrane domain of classical cadherins and increases cell–cell junction stability. Overexpression of p120 modulates the activity of Rho family GTPases and augments cell migratory ability. Here we show that down-regulation of p120 in epithelial MCF-7 cells by siRNA leads to a striking decrease in lamellipodial persistence and focal adhesion formation. Similar alterations in lamellipodial activity were observed in MCF-7 cells treated with siRNA to cortactin, an activator of Arp2/3-dependent actin polymerization. We found that, in many cell types, p120 is colocalized with cortactin-containing actin structures not only at cell–cell junctions, but also at extrajunctional sites including membrane ruffles and actin-rich halos around endocytotic vesicles. p120 depletion led to dramatic loss of cortactin and its partner, Arp3, from the cell leading edges. Cortactin and p120 are shown to directly interact with each other via the cortactin N-terminal region. We propose that the mechanism underlying p120 functions at the leading edge involves its cooperation with cortactin. PMID:17576929

  7. p120 catenin regulates lamellipodial dynamics and cell adhesion in cooperation with cortactin.

    PubMed

    Boguslavsky, Shlomit; Grosheva, Inna; Landau, Elad; Shtutman, Michael; Cohen, Miriam; Arnold, Katya; Feinstein, Elena; Geiger, Benjamin; Bershadsky, Alexander

    2007-06-26

    The armadillo-family protein, p120 catenin (p120), binds to the juxtamembrane domain of classical cadherins and increases cell-cell junction stability. Overexpression of p120 modulates the activity of Rho family GTPases and augments cell migratory ability. Here we show that down-regulation of p120 in epithelial MCF-7 cells by siRNA leads to a striking decrease in lamellipodial persistence and focal adhesion formation. Similar alterations in lamellipodial activity were observed in MCF-7 cells treated with siRNA to cortactin, an activator of Arp2/3-dependent actin polymerization. We found that, in many cell types, p120 is colocalized with cortactin-containing actin structures not only at cell-cell junctions, but also at extrajunctional sites including membrane ruffles and actin-rich halos around endocytotic vesicles. p120 depletion led to dramatic loss of cortactin and its partner, Arp3, from the cell leading edges. Cortactin and p120 are shown to directly interact with each other via the cortactin N-terminal region. We propose that the mechanism underlying p120 functions at the leading edge involves its cooperation with cortactin. PMID:17576929

  8. Plasticity of hydrogen bond networks regulates mechanochemistry of cell adhesion complexes.

    PubMed

    Chakrabarti, Shaon; Hinczewski, Michael; Thirumalai, D

    2014-06-24

    Mechanical forces acting on cell adhesion receptor proteins regulate a range of cellular functions by formation and rupture of noncovalent interactions with ligands. Typically, force decreases the lifetimes of intact complexes ("slip bonds"), making the discovery that these lifetimes can also be prolonged ("catch bonds") a surprise. We created a microscopic analytic theory by incorporating the structures of selectin and integrin receptors into a conceptual framework based on the theory of stochastic equations, which quantitatively explains a wide range of experimental data (including catch bonds at low forces and slip bonds at high forces). Catch bonds arise due to force-induced remodeling of hydrogen bond networks, a finding that also accounts for unbinding in structurally unrelated integrin-fibronectin and actomyosin complexes. For the selectin family, remodeling of hydrogen bond networks drives an allosteric transition resulting in the formation of the maximum number of hydrogen bonds determined only by the structure of the receptor and independent of the ligand. A similar transition allows us to predict the increase in the number of hydrogen bonds in a particular allosteric state of α5β1 integrin-fibronectin complex, a conformation which is yet to be crystallized. We also make a testable prediction that a single point mutation (Tyr51Phe) in the ligand associated with selectin should dramatically alter the nature of the catch bond compared with the wild type. Our work suggests that nature uses a ductile network of hydrogen bonds to engineer function over a broad range of forces. PMID:24927549

  9. Tetraspanin CD151 regulates alpha6beta1 integrin adhesion strengthening

    NASA Technical Reports Server (NTRS)

    Lammerding, Jan; Kazarov, Alexander R.; Huang, Hayden; Lee, Richard T.; Hemler, Martin E.

    2003-01-01

    The tetraspanin CD151 molecule associates specifically with laminin-binding integrins, including alpha6beta1. To probe strength of alpha6beta1-dependent adhesion to laminin-1, defined forces (0-1.5 nN) were applied to magnetic laminin-coated microbeads bound to NIH 3T3 cells. For NIH 3T3 cells bearing wild-type CD151, adhesion strengthening was observed, as bead detachment became more difficult over time. In contrast, mutant CD151 (with the C-terminal region replaced) showed impaired adhesion strengthening. Static cell adhesion to laminin-1, and detachment of beads coated with fibronectin or anti-alpha6 antibody were all unaffected by CD151 mutation. Hence, CD151 plays a key role in selectively strengthening alpha6beta1 integrin-mediated adhesion to laminin-1.

  10. Integrin adhesion and force coupling are independently regulated by localized PtdIns(4,5)2 synthesis

    PubMed Central

    Legate, Kyle R; Takahashi, Seiichiro; Bonakdar, Navid; Fabry, Ben; Boettiger, David; Zent, Roy; Fässler, Reinhard

    2011-01-01

    The 90-kDa isoform of the lipid kinase PIP kinase Type I γ (PIPKIγ) localizes to focal adhesions (FAs), where it provides a local source of phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2). Although PtdIns(4,5)P2 regulates the function of several FA-associated molecules, the role of the FA-specific pool of PtdIns(4,5)P2 is not known. We report that the genetic ablation of PIPKIγ specifically from FAs results in defective integrin-mediated adhesion and force coupling. Adhesion defects in cells deficient in FA-PtdIns(4,5)P2 synthesis are corrected within minutes while integrin–actin force coupling remains defective over a longer period. Talin and vinculin, but not kindlin, are less efficiently recruited to new adhesions in these cells. These data demonstrate that the specific depletion of PtdIns(4,5)P2 from FAs temporally separates integrin–ligand binding from integrin–actin force coupling by regulating talin and vinculin recruitment. Furthermore, it suggests that force coupling relies heavily on locally generated PtdIns(4,5)P2 rather than bulk membrane PtdIns(4,5)P2. PMID:21926969

  11. Breast cancer cells expressing stem cell markers CD44+ CD24lo are eliminated by Numb-1 peptide-activated T cells

    PubMed Central

    Mine, Takashi; Matsueda, Satoko; Li, Yufeng; Tokumitsu, Hiroshi; Gao, Hui; Danes, Cristopher; Wong, Kwong-Kwok; Wang, Xinhui; Ferrone, Soldano; Ioannides, Constantin G.

    2009-01-01

    Cancer stem cells (CSC) are resistant to chemoand radiotherapy. To eliminate cells with phenotypic markers of CSC-like we characterized: (1) expression of CD44, CD24, CD133 and MIC-A/B (NKG2 receptors) in breast (MCF7) and ovarian (SK-OV-3) cells resistant to gemcitabine (GEM), paclitaxel (PTX) and 5-Xuorouracil (5-FU) and (2) their elimination by Numb- and Notch-peptide activated CTL. The number of cells in all populations with the luminal CSC phenotype [epithelial specific antigen+ (ESA) CD44hi CD24lo, CD44hi CD133+, and CD133+ CD24lo] increased in drug-resistant MCF7 and SK-OV-3 cells. Similarly, the number of cells with expressed MIC-A/B increased 4 times in drug-resistant tumor cells compared with drug-sensitive cells. GEMRes MCF7 cells had lower levels of the Notch-1-extracellular domain (NECD) and Notch trans-membrane intracellular domain (TMIC) than GEMSens MCF7. The levels of Numb, and Numb-L-[P]-Ser265 were similar in GEMRes and GEMSens MCF7 cells. Only the levels of Numb-L (long)-Ser295 decreased slightly. This finding suggests that Notch-1 cleavage to TMIC is inhibited in GEMRes MCF7 cells. PBMC activated by natural immunogenic peptides Notch-1 (2112−2120) and Numb-1 (87−95) eliminated NICDpositive, CD24hi CD24lo MCF7 cells. It is likely that the immunogenic Numb-1 peptide in MCF7 cells originated from Numb, [P]-lated by an unknown kinase, because staurosporine but not wortmannin and MAPK-inhibitors decreased peptide presentation. Numb and Notch are antagonistic proteins which degrade each other to stop and activate cell proliferation, respectively. Their peptides are presented alternatively. Targeting both antagonistic proteins should be useful to prevent metastases in patients whose tumors are resistant to conventional treatments. PMID:19048252

  12. Reversibly crosslinked hyaluronic acid nanoparticles for active targeting and intelligent delivery of doxorubicin to drug resistant CD44+ human breast tumor xenografts.

    PubMed

    Zhong, Yinan; Zhang, Jian; Cheng, Ru; Deng, Chao; Meng, Fenghua; Xie, Fang; Zhong, Zhiyuan

    2015-05-10

    The existence of drug resistance poses a major obstacle for the treatment of various malignant human cancers. Here, we report on reduction-sensitive reversibly crosslinked hyaluronic acid (HA) nanoparticles based on HA-Lys-LA conjugates (Lys: l-lysine methyl ester, LA: lipoic acid) for active targeting delivery of doxorubicin (DOX) to CD44+ breast cancers in vitro and in vivo, effectively overcoming drug resistance (ADR). HA-Lys-LA with degrees of substitution of 5, 10 and 28% formed robust nano-sized nanoparticles (152-219nm) following auto-crosslinking. DOX-loaded crosslinked nanoparticles revealed inhibited DOX release under physiological conditions while fast drug release in the presence of 10mM glutathione (GSH). Notably, MTT assays showed that DOX-loaded crosslinked HA-Lys-LA10 nanoparticles possessed an apparent targetability and a superior antitumor activity toward CD44 receptor overexpressing DOX-resistant MCF-7 human breast cancer cells (MCF-7/ADR). The in vivo pharmacokinetics and biodistribution studies in MCF-7/ADR tumor xenografts in nude mice showed that DOX-loaded crosslinked HA-Lys-LA10 nanoparticles had a prolonged circulation time and a remarkably high accumulation in the tumor (12.71%ID/g). Notably, DOX-loaded crosslinked HA-Lys-LA10 nanoparticles exhibited effective inhibition of tumor growth while continuous tumor growth was observed for mice treated with free drug. The Kaplan-Meier survival curves showed that in contrast to control groups, all mice treated with DOX-loaded crosslinked HA-Lys-LA10 nanoparticles survived over an experimental period of 44days. Importantly, DOX-loaded crosslinked HA nanoparticles caused low side effects. The reversibly crosslinked hyaluronic acid nanoparticles with excellent biocompatibility, CD44-targetability, and effective reversal of drug resistance have a great potential in cancer therapy. PMID:25596560

  13. Hyaluronic acid-shelled acid-activatable paclitaxel prodrug micelles effectively target and treat CD44-overexpressing human breast tumor xenografts in vivo.

    PubMed

    Zhong, Yinan; Goltsche, Katharina; Cheng, Liang; Xie, Fang; Meng, Fenghua; Deng, Chao; Zhong, Zhiyuan; Haag, Rainer

    2016-04-01

    The therapeutic efficacy of nanoscale anticancer drug delivery systems is severely truncated by their low tumor-targetability and inefficient drug release at the target site. Here, we report the design and development of novel endosomal pH-activatable paclitaxel prodrug micelles based on hyaluronic acid-b-dendritic oligoglycerol (HA-dOG-PTX-PM) for active targeting and effective treatment of CD44-overexpressing human breast cancer xenografts in nude mice. HA-dOG-PTX-PM had a high drug content of 20.6 wt.% and an average diameter of 155 nm. The release of PTX was slow at pH 7.4 but greatly accelerated at endosomal pH. MTT assays, flow cytometry and confocal experiments showed that HA-dOG-PTX-PM possessed a high targetability and antitumor activity toward CD44 receptor overexpressing MCF-7 human breast cancer cells. The in vivo pharmacokinetics and biodistribution studies showed that HA-dOG-PTX-PM had a prolonged circulation time in the nude mice and a remarkably high accumulation in the MCF-7 tumor (6.19%ID/g at 12 h post injection). Interestingly, HA-dOG-PTX-PM could effectively treat mice bearing MCF-7 human breast tumor xenografts with little side effects, resulting in complete inhibition of tumor growth and a 100% survival rate over an experimental period of 55 days. These results indicate that hyaluronic acid-shelled acid-activatable PTX prodrug micelles have a great potential for targeted chemotherapy of CD44-positive cancers. PMID:26851390

  14. Synergistic active targeting of dually integrin αvβ3/CD44-targeted nanoparticles to B16F10 tumors located at different sites of mouse bodies.

    PubMed

    Shi, Sanjun; Zhou, Min; Li, Xin; Hu, Min; Li, Chenwen; Li, Min; Sheng, Fangfang; Li, Zhuoheng; Wu, Guolin; Luo, Minghe; Cui, Huanhuan; Li, Ziwei; Fu, Ruoqiu; Xiang, Mingfeng; Xu, Jing; Zhang, Qian; Lu, Laichun

    2016-08-10

    Conventional enhanced permeation and retention (EPR) mediates the effects of many drugs, including the accumulation of nanocarriers at tumor sites, but its efficiency remains low. In this study, this limitation was overcome by developing a dual-targeting delivery system based on hyaluronan (HA, a major ligand of CD44) and tetraiodothyroacetic acid (tetrac, a specific ligand of αvβ3), which was exploited to carry docetaxel (DTX) for the synergistic active targeting to tumors. First, a tetrac-HA (TeHA) conjugate was synthesized and grafted onto the surfaces of solid lipid nanoparticles (SLNs) (TeHA-SLNs/DTX), with a high encapsulation efficiency of >91.6%. The resulting SLNs exhibited an approximately toroid morphology revealed using TEM. The cellular uptake and cytotoxicity of various formulations on CD44/αvβ3-enriched B16F10 cells were then assessed, and both results confirmed the selective uptake and high cytotoxicity of the TeHA-SLNs/DTX in a TeHA-dependent manner. In vivo imaging and vessel distribution tests revealed the efficiency of synergistic active targeting was higher than that of EPR-mediated passive targeting by the TeHA-SLNs to αvβ3-expressing tumor blood vessels and CD44-expressing tumor cells via selective targeting. Finally, in both xenograft tumor mice and in situ lung metastasis tumor mice, tumor growth was significantly inhibited by TeHA-SLNs/DTX. Therefore, TeHA-SLNs are an efficient system for the dual-targeted delivery of drugs to treat cancer in vivo. PMID:27235150

  15. Combination wt-p53 and MicroRNA-125b Transfection in a Genetically Engineered Lung Cancer Model Using Dual CD44/EGFR-targeting Nanoparticles.

    PubMed

    Talekar, Meghna; Trivedi, Malav; Shah, Parin; Ouyang, Qijun; Oka, Adwait; Gandham, Srujan; Amiji, Mansoor M

    2016-04-01

    Mutations in KRAS and p53 signaling pathways contribute to loss of responsiveness to current therapies and a decreased survival in lung cancer. In this study, we have investigated the delivery and transfection of wild-type (wt-) p53 and microRNA-125b (miR-125b) expressing plasmid DNA, in SK-LU-1 human lung adenocarcinoma cells as well as in Kras(G12D)/p53(fl/fl) (KP) genetically engineered mouse model of lung cancer. Systemic plasmid DNA delivery with dual CD44/EGFR-targeted hyaluronic acid (HA)-based nanoparticles (NPs) resulted in a 2- to 20-fold increase in wt-p53 and miR-125b gene expression in SK-LU-1 cells. This resulted in enhanced apoptotic activity as seen with increased APAF-1 and caspase-3 gene expression. Similarly, in vivo evaluations in KP mouse model indicated successful CD44/EGFR-targeted delivery. Tumor growth inhibition and apoptotic induction were also observed with (wt-p53+miR125b) combination therapy in KP tumor model. Lastly, J774.A1 murine macrophages co-cultured with transfected SK-LU-1 cells showed a 14- to 35-fold increase in the iNOS-Arg-1 ratio, supportive of previous results demonstrating a role of miR-125b in macrophage repolarization. Overall, these results show tremendous promise of wt-p53 and miR-125b gene therapy using dual CD44/EGFR-targeting HA NP vector for effective treatment of lung cancer. PMID:26686386

  16. Integrin-linked kinase regulates oligodendrocyte cytoskeleton, growth cone, and adhesion dynamics.

    PubMed

    Michalski, John-Paul; Cummings, Sarah E; O'Meara, Ryan W; Kothary, Rashmi

    2016-02-01

    Integrin-linked kinase (ILK), a focal adhesion protein, brokers the link between cytoskeleton, cell membrane, and extracellular environment. Here, we demonstrate a role for ILK in laminin-2-mediated adhesion in primary murine oligodendrocytes (OLs) - with ILK loss leading to severe defects in process branching and outgrowth. These defects were partially recovered when the ILK-depleted OLs were instead grown on the non-integrin-activating substrate poly-l-lysine. Intriguingly, ILK loss on the neutral poly-l-lysine substrate led to swelling at the tips of OL processes, which we identified as enlarged growth cones. Employing the bloated ILK-depleted growth cones as template, we demonstrate the appearance of distinct cytoskeletal domains within OL growth cones bearing classic neuronal growth cone architecture. Further, microtubule organization was severely perturbed following ILK loss, with centripetal microtubule looping and failure to bundle occurring in a laminin-2-independent manner. Together, our work highlights differences in specific aspects of OL biology as driven by laminin-2-dependent or independent ILK governed mechanisms. We also reinforce the idea of OLs as growth cone bearing cells and describe the neuronal-like cytoskeleton therein. Finally, we demonstrate a role for ILK in OL growth cone maturation through microtubule regulation, the loss of which translates to decreased process length and myelin production capacity. We describe herein how different substrates fundamentally alter the oligodendrocyte's response to loss of integrin-linked kinase (ILK). On laminin-2 (Ln-2), ILK-depleted oligodendrocytes appear stunted and malformed, while on the non-integrin-activating substrate PLL branching and membrane formation are restored. We also reinforce the idea of oligodendrocytes as growth cone-bearing cells, detailing the growth cone's cytoskeletal architecture. Strikingly, loss of ILK on poly-l-lysine leads to growth cone swelling, the structure's size and

  17. [AMP-activated protein kinase activation regulates adhesion of monocytes to vascular endothelial cells and the underlying mechanism].

    PubMed

    Bai, Hong-Bo; Wang, Yun; Zhang, Yu-Hua; Zhang, Yuan

    2016-02-25

    The present study was aimed to explore the effect of AMP-activated protein kinase (AMPK) on monocyte adhesion to vascular endothelial cells and underlying molecular mechanism. Tumor necrosis factor α (TNFα)-activated human aortic endothelial cells (HAECs) were treated with different concentrations of AMPK agonist 5-Aminoimidazole-4-carboxamide-1-β-D-ribonucleotide (AICAR) or AMPK inhibitor compound C. And other HAECs were overexpressed with constitutive active or dominant negative AMPK protein and then treated with TNFα. The rates of monocytes adhering to endothelial cells were detected by fluorescent staining. Intercellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) mRNA levels and protein secretions were detected by quantitative PCR and ELISA, respectively. Acetylation of NF-κB p65 at lysine 221 site was assessed by Western blot. NF-κB p65 DNA binding activity was analyzed by an ELISA-based method. By using small interfering RNA based strategy, p300 expression in HAECs was down-regulated and then cells were incubated with TNFα. NF-κB p65 DNA binding activity, ICAM-1 and VCAM-1 expressions and adhesion rates were detected, respectively. The activity of p300 was also detected by ELISA. The results showed that AICAR treatment significantly reduced monocyte-endothelial adhesion rate, as well as ICAM-1 and VCAM-1 mRNA levels and protein secretions, in TNFα-activated HAECs. Moreover, transfection of constitutive active AMPKα but not dominant negative AMPKα strongly diminished TNFα-induced upregulation of ICAM-1 and VCAM-1 mRNA expressions and secretions, as well as monocyte-endothelial adhesion. Furthermore, AMPK activation decreased TNFα-mediated acetylation of NF-κB p65 at Lys221 site and reduced NF-κB p65 DNA binding activity. Silencing p300 by siRNA significantly abolished the effect of TNFα- induced adhesion molecules expression and monocyte-endothelial adhesion. Blocking AMPK activation by compound C almost

  18. Positive association between CD44 gene rs13347 C>T polymorphism and risk of cancer in Asians: a systemic review and meta-analysis

    PubMed Central

    Shi, Jinan; Duan, Yin; Pan, Lei; Zhou, Xiaoxi

    2016-01-01

    Background Cluster of differentiation 44 (CD44) is an important surface marker of cancer stem cells in a variety of tumors. A number of previous studies have been conducted to investigate the association between CD44 gene rs13347 C>T polymorphism and cancer risk in humans; nevertheless, the results remain controversial. We therefore performed this meta-analysis to confirm the role of this polymorphism in susceptibility to human cancer. Materials and methods The studies published up to December 2015 were searched in PubMed, Web of Science, and China National Knowledge Infrastructure databases. Twelve eligible case–control studies were identified, involving a total of 6,982 cases and 7,430 controls. Pooled odds ratio (OR) and corresponding 95% confidence interval (CI) were calculated using a fixed or random-effect model to estimate the strength of the association. Results The results of the overall analyses indicated that CD44 gene rs13347 polymorphism was significantly associated with cancer risk in Asians (CT vs CC: OR =1.35, 95% CI =1.12–1.62; TT vs CC: OR =1.99, 95% CI =1.52–2.60; TT + CT vs CC: OR =1.41, 95% CI =1.16–1.71; and TT vs CC + CT: OR =1.74, 95% CI =1.41–2.14), especially in Chinese population (CT vs CC: OR =1.42, 95% CI =1.16–1.75; TT vs CC: OR =2.13, 95% CI =1.58–2.86; TT + CT vs CC: OR =1.50, 95% CI =1.21–1.87; and TT vs CC + CT: OR =1.80, 95% CI =1.43–2.26). In stratified analyses by cancer types, there was evidence for an association between this polymorphism and nasopharyngeal cancer and breast cancer, respectively. Conclusion The results of this meta-analysis suggest that the CD44 gene rs13347 C>T polymorphism is associated with elevated risk of human cancer in Asians, especially in Chinese population. Further well-designed studies on a larger population covering other ethnicities should be carried out to validate our results. PMID:27366086

  19. Differential diagnosis of urothelial carcinoma in situ from non-neoplastic urothelia: Analysis of CK20, CD44, P53 and Ki67

    PubMed Central

    Asgari, Mojgan; Nabi Maybodi, Mahtab; Abolhasani, Maryam

    2016-01-01

    Background: Flat urothelial lesions comprise a spectrum of morphologic changes ranging from reactive atypia to carcinoma in situ (CIS). Urothelial dysplasia and CIS are associated with the recurrence and progression of urothelial carcinoma. Distinguishing CIS and dysplasia from reactive atypia based on histolopathogical features alone is often difficult. Using different immunohistochemical markers such as Cytokeratin 20 (CK20), CD44, p53, and Ki-67 is recommended for differential diagnosis. The aim of this study was to evaluate the immunohistochemical pattern of these antibodies to differentiate different flat urothelial lesions. Methods: In this cross- sectional study, three groups of bladder biopsy specimens were evaluated: 20 samples with reactive urothelial lesions, 20 histologically diagnosed as CIS, and 20 morphologically normal samples. Immunohistochemical staining of CK20, p53, CD44 and Ki-67 markers was performed on paraffin-embedded blocks. The groups were compared using chi square test, and the diagnostic value of the markers were evaluated with sensitivity, specificity, positive and negative predictive values. Results: CK20 was full thickness positive in 15 (75%) CIS samples and negative in all samples of the normal and reactive groups (p<0.001); CD44 was positive in 2 (10%) cases of the CIS group and in 17 (85%) of the reactive group; this marker was negative in all the normal samples (p<0.001). P53 was positive in 12 (60%) samples of the CIS group and negative in all samples of the normal and reactive groups (p<0.001). Ki67 was positive in 13 (65%) samples of the CIS group and 1 (5%) sample of the reactive group. This marker was negative in all samples of the normal group (p<0.001). Conclusion: The results of this study revealed that CK20, CD44, P53 and Ki67 are useful in distinguishing CIS from reactive and normal samples. However, they should be used in a panel including at least three markers. Correlation with the morphologic features is necessary

  20. A New Hyaluronic Acid Derivative Obtained from Atom Transfer Radical Polymerization as a siRNA Vector for CD44 Receptor Tumor Targeting.

    PubMed

    Palumbo, Fabio Salvatore; Bavuso Volpe, Antonella; Bongiovì, Flavia; Pitarresi, Giovanna; Giammona, Gaetano

    2015-11-01

    Two derivatives of hyaluronic acid (HA) have been synthesized by atom transfer radical polymerization (ATRP), starting from an ethylenediamino HA derivative (HA-EDA) and by using diethylaminoethyl methacrylate (DEAEMA) as a monomer for polymerization. Both samples, indicated as HA-EDA-pDEAEMA a and b, are able to condense siRNA, as determined by gel retardation assay and resulting complexes show a size and a zeta potential value dependent on polymerization number, as determined by dynamic light scattering measurements. In vitro studies performed on HCT 116 cell line, that over express CD44 receptor, demonstrate a receptor mediated uptake of complexes, regardless of their surface charge. PMID:26136372

  1. A role for the retinoblastoma protein as a regulator of mouse osteoblast cell adhesion: implications for osteogenesis and osteosarcoma formation.

    PubMed

    Sosa-García, Bernadette; Gunduz, Volkan; Vázquez-Rivera, Viviana; Cress, W Douglas; Wright, Gabriela; Bian, Haikuo; Hinds, Philip W; Santiago-Cardona, Pedro G

    2010-01-01

    The retinoblastoma protein (pRb) is a cell cycle regulator inactivated in most human cancers. Loss of pRb function results from mutations in the gene coding for pRb or for any of its upstream regulators. Although pRb is predominantly known as a cell cycle repressor, our data point to additional pRb functions in cell adhesion. Our data show that pRb regulates the expression of a wide repertoire of cell adhesion genes and regulates the assembly of the adherens junctions required for cell adhesion. We conducted our studies in osteoblasts, which depend on both pRb and on cell-to-cell contacts for their differentiation and function. We generated knockout mice in which the RB gene was excised specifically in osteoblasts using the cre-lox P system and found that osteoblasts from pRb knockout mice did not assemble adherens junction at their membranes. pRb depletion in wild type osteoblasts using RNAi also disrupted adherens junctions. Microarrays comparing pRb-expressing and pRb-deficient osteoblasts showed that pRb controls the expression of a number of cell adhesion genes, including cadherins. Furthermore, pRb knockout mice showed bone abnormalities consistent with osteoblast adhesion defects. We also found that pRb controls the function of merlin, a well-known regulator of adherens junction assembly, by repressing Rac1 and its effector Pak1. Using qRT-PCR, immunoblots, co-immunoprecipitation assays, and immunofluorescent labeling, we observed that pRb loss resulted in Rac1 and Pak1 overexpression concomitant with merlin inactivation by Pak1, merlin detachment from the membrane, and adherens junction loss. Our data support a pRb function in cell adhesion while elucidating the mechanism for this function. Our work suggests that in some tumor types pRb inactivation results in both a loss of cell cycle control that promotes initial tumor growth as well as in a loss of cell-to-cell contacts, which contributes to later stages of metastasis. PMID:21085651

  2. A protein interaction map for cell-cell adhesion regulators identifies DUSP23 as a novel phosphatase for β-catenin

    PubMed Central

    Gallegos, Lisa Leon; Ng, Mei Rosa; Sowa, Mathew E.; Selfors, Laura M.; White, Anne; Zervantonakis, Ioannis K.; Singh, Pragya; Dhakal, Sabin; Harper, J. Wade; Brugge, Joan S.

    2016-01-01

    Cell-cell adhesion is central to morphogenesis and maintenance of epithelial cell state. We previously identified 27 candidate cell-cell adhesion regulatory proteins (CCARPs) whose down-regulation disrupts epithelial cell-cell adhesion during collective migration. Using a protein interaction mapping strategy, we found that 18 CCARPs link to core components of adherens junctions or desmosomes. We further mapped linkages between the CCARPs and other known cell-cell adhesion proteins, including hits from recent screens uncovering novel components of E-cadherin adhesions. Mechanistic studies of one novel CCARP which links to multiple cell-cell adhesion proteins, the phosphatase DUSP23, revealed that it promotes dephosphorylation of β-catenin at Tyr 142 and enhances the interaction between α- and β-catenin. DUSP23 knockdown specifically diminished adhesion to E-cadherin without altering adhesion to fibronectin matrix proteins. Furthermore, DUS