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Correlação dos ligantes de quimiocinas e de seus respectivos receptores em relação à invasão de linfonodos nos carcinomas epidermóides em cabeça e pescoço; Correlation of chemokine ligands and its receptors with lymph node metastasis in Head and Neck Squamous Cell Carcinoma

Campofiorito, Cristina Maria Meireles
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 02/03/2007 PT
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46.63%
Tanto a invasão local como o comprometimento de linfonodos cervicais tem grande impacto na sobrevida de pacientes portadores de carcinomas epidermóides de cabeça e pescoço. Em nosso trabalho nós primeiramente determinamos a expressão dos receptores de quimiocinas de CXCR1 a CXCR5, além de CCR7 e CX3CR1 pelo método do ensaio de proteção à ribonuclease (RPA) em 98 fragmentos de tumores primários, 91 fragmentos de mucosas adjacentes e 26 linfonodos comprometidos e correlacionamos estes dados com parâmetros anátomo-patológicos e sobrevida. CXCL12 ligante do receptor CXCR4 e CCL19 e CCL21 ambos ligantes de CCR7 foram determinados em 38 fragmentos de tumores, 33 mucosas adjacentes e 25 linfonodos comprometidos pela técnica de real-time PCR. Os tumores primários apresentam expressão aumentada do mRNA de CXCR1 (P=0.013), CXCR3 (P=0.008) e CXCR4 (P=0.025). Não observamos correlações entre status linfonodal ou tamanho de tumor. Os linfonodos comprometidos expressam mais mRNA dos receptores de quimiocinas CXCR4, CXCR5, CCR7 e CX3CR1 (todos com P<0.0001) em comparação aos tumores comprometidos. Observamos um aumento de sobrevida (P=0.048) e uma tendência a aumento de sobrevida livre de doença (P=0.074) nos pacientes negativos para a expressão de CX3CR1 (n=17) em comparação aos pacientes positivos (n=21) somente no subgrupo de pacientes portadores de carcinomas da cavidade oral. O mesmo foi observado com os pacientes CCR7 negativos também no subgrupo de pacientes portadores de carcinomas da cavidade oral...

Expressão de CXCR7 e CXCR4 em em astrocitomas iniltrativos em relação ao tecido cerebral não neoplásico e sua interação com HIF1alfa e IDH1; CXCR7 and CXCR4 expressions in infiltrative astrocytomas and their interactions with HIF1alfa and IDH

Bianco, André de Macedo
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 12/09/2013 PT
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Introdução: Existem dados suficientes disponíveis demonstrando a importância da quimiocina CXCL12 e seu receptor CXCR4 na progressão tumoral e angiogênese dos gliomas. O CXCR4 é regulado positivamente pelo HIF1alfa. Recentemente um novo receptor com maior afinidade à CXCL12 foi identificado, o receptor órfão RDC1, agora denominado CXCR7. O objetivo deste estudo é investigar a expressão de mRNA CXCR7 em tecidos astrocitomas difusos e avaliar suas interações com expressão CXCR4 e HIF1alfa, bem como analisar sua relação com mutação do IDH1. Métodos: A expressão do CXCR7, CXCR4, IDH1 e HIF1alfa foram avaliadas por PCR quantitativo em tempo real (qRT-PCR) em 129 amostras congeladas de astrocitomas (25 astrocitoma difuso - AGII, 18 de astrocitoma anaplásico - AGIII e 86 glioblastoma - GBM) e 22 amostras de tecido cerebral não neoplásico (NN) obtidos de cirurgia de epilepsia. A mutação do IDH1 previamente determinada foi analisada em relação aos níveis de expressões de mRNA do CXCR7, CXCR4 e HIF1alfa, combinado com os parâmetros clínico-patológicos e sobrevida global. Adicionalmente, a expressão proteica do CXCR7 foi analisada por imuno-histoquímica em astrocitomas de diferentes graus e em linhagem celular de glioma (U87MG) por microscopia confocal. Resultados: Houve diferença significativa nos níveis de expressão dos genes estudados entre astrocitomas e NN (p < 0...

Expression of the chemokine receptor CXCR4 on lymphocytes of leprosy patients

Mendonça,V.A.; Alvim de Melo,G.E.B.; Araújo,M.G.; Borges,V.O.; Costa,R.D.; Martins-Filho,O.A.; Teixeira- Carvalho,A.; Sathler-Avelar,R.; Teixeira,M.M.; Teixeira,A.L.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2011 EN
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Leprosy is caused by Mycobacterium leprae, which induces chronic granulomatous infection of the skin and peripheral nerves. The disease ranges from the tuberculoid to the lepromatous forms, depending on the cellular immune response of the host. Chemokines are thought to be involved in the immunopathogenesis of leprosy, but few studies have investigated the expression of chemokine receptors on leukocytes of leprosy patients. In the present study, we evaluated 21 leprosy patients (M/F: 16/5) with a new diagnosis from the Dermatology Outpatient Clinic of the University Hospital, Federal University of Minas Gerais. The control group was composed of 20 healthy members (M/F: 15/5) of the community recruited by means of announcements. The expression of CCR2, CCR3, CCR5, and CXCR4 was investigated by flow cytometry on the surface of peripheral blood lymphocytes. There was a decrease in percentage of CD3+CXCR4+ and CD4+CXCR4+ lymphocytes in the peripheral blood of leprosy patients (median [range], 17.6 [2.7-41.9] and 65.3 [3.9-91.9], respectively) compared to the control group (median [range], 43.0 [3.7-61.3] and 77.2 [43.6-93.5], respectively). The percentage of CD4+CXCR4+ was significantly lower in patients with the tuberculoid form (median [range]...

Signal Transduction Due to HIV-1 Envelope Interactions with Chemokine Receptors CXCR4 or CCR5

Davis, Craig B.; Dikic, Ivan; Unutmaz, Derya; Hill, C. Mark; Arthos, James; Siani, Michael A.; Thompson, Darren A.; Schlessinger, Joseph; Littman, Dan R.
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 17/11/1997 EN
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Infection with HIV-1 requires expression of CD4 and the chemokine receptors CXCR4 or CCR5 at the target cell surface. Engagement of these receptors by the HIV-1 envelope glycoprotein is essential for membrane fusion, but may additionally activate intracellular signaling pathways. In this study, we demonstrate that chemokines and HIV-1 envelope glycoproteins from both T-tropic and macrophage-tropic strains rapidly induce tyrosine phosphorylation of the protein tyrosine kinase Pyk2. The response requires CXCR4 and CCR5 to be accessible on the cell surface. The results presented here provide the first evidence for activation of an intracellular signaling event that can initiate multiple signaling pathways as a consequence of contact between HIV-1 and chemokine receptors.

REGULATION OF EXPRESSION OF STROMAL-DERIVED FACTOR-1 (SDF-1) RECEPTORS: CXCR4 AND CXCR7 IN HUMAN RHADOMYOSARCOMAS

Tarnowski, Maciej; Grymula, Katarzyna; Reca, Ryan; Jankowski, Kacper; Maksym, Radoslaw; Tarnowska, Joanna; Przybylski, Grzegorz; Barr, Frederic G; Kucia, Magdalena; Ratajczak, Mariusz Z
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
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Rhabdomyosarcomas (RMS) express CXCR4 and CXCR7 receptors that bind prometastatic α-chemokine stromal derived factor-1. In this report we analyzed the activity of both promoters in a model of less metastatic human embryonal-RMS cell line (RD) and more metastatic alveolar-like RMS (RD cells transduced with Paired box gene 3/forkhead homolog - PAX3-FKHR fusion gene). First, CXCR4 is barely detectable on RD and becomes upregulated on RD/PAX3-FKHR cells. In contrast, CXCR7 highly expressed on RD becomes downregulated in RD/PAX3-FKHR cells. Next, promoter deletion and mutation studies revealed that while: i) expression of CXCR4 in RD and RD/PAX3-FKHR cells required nuclear respiratory factor-1 (NRF-1) binding site and ii) was additionally upregulated by direct interaction of NRF-1 with PAX3-FKHR, CXCR7 promoter activity required a proximal nuclear factor-kappa B (NF-κB) binding motif. The requirement of these factors for CXCR4 and CXCR7 promoter activities was additionally supported after blocking NRF-1 and NF-κB. Furthermore, CXCR4 expression in PAX3-FKHR+ RMS cells seems to be enhanced because of the interaction of PAX3-FKHR and NRF-1 proteins in the proximal part of the promoter that prevents access of the negative regulator of transcription YY1 to its binding site. Finally...

Near-infrared molecular imaging of tumors via chemokine receptors CXCR4 and CXCR7

Meincke, Manuela; Tiwari, Sanjay; Hattermann, Kirsten; Kalthoff, Holger; Mentlein, Rolf
Fonte: Springer Netherlands Publicador: Springer Netherlands
Tipo: Artigo de Revista Científica
EN
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The chemokine CXCL12/SDF-1 and its receptors CXCR4 and CXCR7 play a major role in tumor invasion, proliferation and metastasis. Since both receptors are overexpressed on distinct tumor cells and on the tumor vasculature, we evaluated their potential as targets for detection of cancers by molecular imaging. We synthesized conjugates of CXCL12 and the near-infrared (NIR) fluorescent dye IRDye®800CW, tested their selectivity, sensitivity and biological activity in vitro and their feasibility to visualize tumors in vivo. Purified CXCL12-conjugates detected in vitro as low as 500 A764 human glioma cells or MCF-7 breast cancer cells that express CXCR7 alone or together with CXCR4. Binding was time- and concentration-dependent, and the label could be competitively displaced by the native peptide. Control conjugates with bovine serum albumin or lactalbumin failed to label the cells. In mice, the conjugate distributed rapidly. After 1–92 h, subcutaneous tumors of human MCF-7 and A764 cells in immunodeficient mice were detected with high sensitivity. Background was observed in particular in liver within the first 24 h, but also skull and hind limbs yielded some background. Overall, fluorescent CXCL12-conjugates are sensitive and selective probes to detect solid and metastatic tumors by targeting tumor cells and tumor vasculature.

Expression and Functional Heterogeneity of Chemokine Receptors CXCR4 and CXCR7 in Primary Patient-Derived Glioblastoma Cells

Liu, Che; Pham, Kien; Luo, Defang; Reynolds, Brent A.; Hothi, Parvinder; Foltz, Gregory; Harrison, Jeffrey K.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 21/03/2013 EN
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Glioblastoma (GBM) is the most common primary brain tumor in adults. The poor prognosis and minimally successful treatments of these tumors indicates a need to identify new therapeutic targets. Therapy resistance of GBMs is attributed to heterogeneity of the glioblastoma due to genetic alterations and functional subpopulations. Chemokine receptors CXCR4 and CXCR7 play important roles in progression of various cancers although the specific functions of the CXCL12−CXCR4−CXCR7 axis in GBM are less characterized. In this study we examined the expression and function of CXCR4 and CXCR7 in four primary patient-derived GBM cell lines of the proliferative subclass, investigating their roles in in vitro growth, migration, sphere and tube formation. CXCR4 and CXCR7 cell surface expression was heterogeneous both between and within each cell line examined, which was not reflected by RT-PCR analysis. Variable percentages of CXCR4+CXCR7− (CXCR4 single positive), CXCR4−CXCR7+ (CXCR7 single positive), CXCR4+CXCR7+ (double positive), and CXCR4−CXCR7− (double negative) subpopulations were evident across the lines examined. A subpopulation of slow cell cycling cells was enriched in CXCR4 and CXCR7. CXCR4+, CXCR7+, and CXCR4+/CXCR7+ subpopulations were able to initiate intracranial tumors in vivo. CXCL12 stimulated in vitro cell growth...

Allosteric Peptide Regulators of Chemokine Receptors CXCR4 and CXCR7

Ehrlich, Anna; Ray, Paramita; Luker, Kathryn E.; Lolis, Elias; Luker, Gary D.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
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The chemokine CXCL12 and its shared seven-transmembrane receptors CXCR4 and CXCR7 regulate diseases including cancer, atherosclerosis, autoimmunity, and HIV infection, making these molecules promising drug targets. These molecules also control key processes in normal development and physiology, suggesting the need to selectively modulate CXCR4 and/or CXCR7 functions and signaling to reduce potential complications of long-term therapy. We previously identified two peptides that functioned as allosteric agonists driving CXCR4-dependent chemotaxis, providing key structural information to design a small number of additional peptides to investigate determinants of CXCL12 interactions and signaling through CXCR4 and CXCR7. In the current study, we show that the previously identified peptides only minimally activated CXCR4 signaling through the cytosolic adapter protein β-arrestin 2 and do not initiate signaling to ERK1/2. By comparison, peptides with diverse N-terminal amino acid sequences effectively activated CXCR7 signaling to β-arrestin 2. One peptide, designated as GSLW based on its N-terminal amino acids, activated CXCR7 signaling and potentiated CXCL12-CXCR7 signaling without blocking the scavenger function of CXCR7 to internalize CXCL12. These results advance our understanding of CXCR7 ligand recognition and signaling...

Differential functional activation of chemokine receptor CXCR4 is mediated by G proteins in breast cancer cells

Holland, J.; Kochetkova, M.; Akekawatchai, C.; Dottore, M.; Lopez, A.; McColl, S.
Fonte: Amer Assoc Cancer Research Publicador: Amer Assoc Cancer Research
Tipo: Artigo de Revista Científica
Publicado em //2006 EN
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CXCR4 is a G protein–coupled receptor of considerable biological significance, and among its numerous functions, it is suggested to play a critical role in cancer metastasis. We have investigated the expression and function of CXCR4 in a range of breast cancer cell lines covering a spectrum of invasive phenotypes and found that, while surface levels of CXCR4 were uniform across the entire panel, only highly invasive cells that are metastatic in immunocompromised mice expressed functional receptors. CXCL12/SDF-1 induced cellular responses such as calcium mobilization, actin polymerization, and chemotaxis in metastatic cells, whereas noninvasive cells were unresponsive. Moreover, CXCL12 activated multiple signaling pathways downstream of G proteins in highly invasive cells but failed to activate any of the examined kinase cascades in noninvasive cell lines. This blockade in nonmetastatic cell lines seems to be due to the inability of G protein A and B subunits to form a heterotrimeric complex with CXCR4. GA and GB were able to bind to CXCR4 independently in all cell lines, but the association of G protein AB; heterotrimers with the receptor, a prerequisite for signal transduction downstream from G protein–coupled receptors, was only observed in the highly invasive cell lines. Our findings show...

Transactivation of CXCR4 by the insulin-like growth factor-1 receptor (IGF-1R) in human MDA-MB-231 breast cancer epithelial cells

Akekawatchai, C.; Holland, J.; Kochetkova, M.; Wallace, J.; McColl, S.
Fonte: Amer Soc Biochemistry Molecular Biology Inc Publicador: Amer Soc Biochemistry Molecular Biology Inc
Tipo: Artigo de Revista Científica
Publicado em //2005 EN
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In the multimolecular environment in tissues and organs, crosstalk between growth factor and G protein-coupled receptors is likely to play an important role in both normal and pathological responses. In this report, we demonstrate transactivation of the chemokine receptor CXCR4 by the growth factor insulin-like growth factor (IGF)-1 is required for IGF-1-induced cell migration in metastatic MDA-MB-231 cells. The induction of chemotaxis in MDAMB- 231 cells by IGF-1 was inhibited by pretreatment of the cells with pertussis toxin (PTX) and by RNAi-mediated knockdown of CXCR4. Transactivation of the CXCR4 pathway by IGF-1 occurred independently of CXCL12, the chemokine ligand of CXCR4. Neither CXCR4 knockdown nor PTX had any effect on the ability of IGF-1 to activate IGF-1R, suggesting thatCXCR4andGproteins are activated subsequent to, or independently of, phosphorylation of IGF-1R by IGF-1. Coprecipitation studies revealed the presence of a constitutive complex containing IGF-1R, CXCR4, and theGprotein subunits, Giα2 and Gß, and stimulation of MDA-MB-231 cells with IGF-1 led to the release of Giα2 and Gß from CXCR4. Based on our findings, we propose that CXCR4 constitutively forms a complex with IGF-1R in MDA-MB-231 cells, and that this interaction allows IGF-1 to activate migrational signaling pathways through CXCR4...

MIF is a noncognate ligand of CXC chemokine receptors in inflammatory and atherogenic cell recruitment

Bernhagen, J.; Krohn, R.; Lue, H.; Gregory, J.; Zernecke, A.; Koenen, R.; Dewor, M.; Georgiev, I.; Schober, A.; Leng, L.; Kooistra, T.; Fingerle-Rowson, G.; Ghezzi, P.; Kleemann, R.; McColl, S.; Bucala, R.; Hickey, M.; Weber, C.
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
Publicado em //2007 EN
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The cytokine macrophage migration inhibitory factor (MIF) plays a critical role in inflammatory diseases and atherogenesis. We identify the chemokine receptors CXCR2 and CXCR4 as functional receptors for MIF. MIF triggered G(alphai)- and integrin-dependent arrest and chemotaxis of monocytes and T cells, rapid integrin activation and calcium influx through CXCR2 or CXCR4. MIF competed with cognate ligands for CXCR4 and CXCR2 binding, and directly bound to CXCR2. CXCR2 and CD74 formed a receptor complex, and monocyte arrest elicited by MIF in inflamed or atherosclerotic arteries involved both CXCR2 and CD74. In vivo, Mif deficiency impaired monocyte adhesion to the arterial wall in atherosclerosis-prone mice, and MIF-induced leukocyte recruitment required Il8rb (which encodes Cxcr2). Blockade of Mif but not of canonical ligands of Cxcr2 or Cxcr4 in mice with advanced atherosclerosis led to plaque regression and reduced monocyte and T-cell content in plaques. By activating both CXCR2 and CXCR4, MIF displays chemokine-like functions and acts as a major regulator of inflammatory cell recruitment and atherogenesis. Targeting MIF in individuals with manifest atherosclerosis can potentially be used to treat this condition.; Jürgen Bernhagen...

Antagonism of the chemokine receptors CXCR3 and CXCR4 reduces the pathology of experimental autoimmune encephalomyelitis

Kohler, R.; Comerford, I.; Townley, S.; Haylock-Jacobs, S.; Clark-Lewis, I.; McColl, S.
Fonte: Int Soc Neuropathology Publicador: Int Soc Neuropathology
Tipo: Artigo de Revista Científica
Publicado em //2008 EN
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Chemokines regulate lymphocyte trafficking under physiologic and pathologic conditions. In this study, we have investigated the role of CXCR3 and CXCR4 in the activation of T lymphocytes and their migration to the central nervous system (CNS) using novel mutant chemokines to antagonize CXCR3 and CXCR4 specifically. A series of truncation mutants of CXCL11, which has the highest affinity for CXCR3, were synthesized, and an antagonist, CXCL11((4-79)), was obtained. CXCL11((4-79)) strongly inhibited the migration of activated mouse T cells in response to all three high-affinity CXCR3 ligands, CXCL9, 10 and 11. CXCL12((P2G2)), while exhibiting minimal agonistic activity, potently inhibited the migration of activated mouse T cells in response to CXCL12. Interfering with the action of CXCR3 and CXCR4 with these synthetic receptor antagonists inhibited experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis and reduced the accumulation of CD4(+) T cells in the CNS. Further investigation demonstrated that CXCL12((P2G2)) inhibited the sensitization phase, whereas CXCL11((4-79)) inhibited the effector phase of the immune response. Our data suggest that simultaneous targeting of CXCR4 and CXCR3 may be of benefit in the treatment of the CNS autoimmune disease.; The definitive version may be found at www.wiley.com

Chemokine receptors CXCR4 and CCR7 promote metastasis by preventing anoikis in cancer cells

Kochetkova, M.; Kumar, S.; McColl, S.
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
Publicado em //2009 EN
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Chemokine receptors are essential mediators of the metastatic spread in various cancer types; however their precise function in the development of secondary tumors remains poorly understood. We report here a novel property of the chemokine receptors CXCR4 and CCR7 in inhibiting detachment-induced cell death – anoikis, which is believed to be one of the major blocks in the metastatic spread of various neoplasms. Activation of these chemokine receptors by their respective ligands, CXCL12 and CCL21 specifically reduced the sensitivity of metastatic breast cancer cells to anoikis by a distinct mechanism of selective regulation of pro-apoptotic Bmf and anti-apoptotic Bcl-xL proteins. Consequently, functional CXCR4 and CCR7 increased cell survival in the absence of correct ECM attachment both in vitro and in vivo. We also demonstrated that preventing chemokine-induced reduction in Bmf levels significantly attenuated breast cancer metastasis in an experimental mouse model. These results provide evidence for a previously unknown axis in malignant tumors, which connects chemokine receptors with deregulated apoptosis in the absence of the appropriate cell – ECM interaction and may offer novel targets for therapeutic intervention for the treatment of metastatic breast and potentially other tumors.; M Kochetkova...

Chemokine/Chemokine receptor interactions in extramedullary leukaemia of the skin in childhood AML: Differential roles for CCR2, CCR5, CXCR4 and CXCR7

Faaij, C.; Willemze, A.; Revesz, T.; Balzarolo, M.; Tensen, C.; Hoogeboom, M.; Vermeer, M.; van Wering, E.; Zwaan, C.; Kaspers, G.; Story, C.; van Halteren, A.; Vossen, J.; Egeler, R.; van Tol, M.; Annels, N.
Fonte: Wiley-Liss Publicador: Wiley-Liss
Tipo: Artigo de Revista Científica
Publicado em //2010 EN
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Chemokine receptor/ligand interactions orchestrate the migration of cells to peripheral tissues such as the skin. We analysed chemokine receptor expression by acute myeloid leukaemic (AML) cells present in peripheral blood (n = 7), bone marrow (n = 6), or skin (n = 11) obtained from 15 paediatric AML patients with skin involvement and in 10 AML patients without skin involvement. High percentages of circulating CCR2(pos) AML cells were only detected in patients with extramedullary disease. Skin-residing AML cells displayed a different set of receptors in situ, namely: CCR5, CXCR4, CXCR7 and CX3CR1. These results suggest the involvement of different chemokine/chemokine receptor interactions in homing and retention of AML blasts in the skin.; Claudia M.J.M. Faaij, Annemieke J. Willemze, Tom Révész, Melania Balzarolo, Cornelis P. Tensen, Manja Hoogeboom, Maarten H. Vermeer, Elisabeth van Wering, Christian M. Zwaan, Gertjan J.L. Kaspers, Colin Story, Astrid G.S. van Halteren, Jaak M. Vossen, R. Maarten Egeler, Maarten J.D. van Tol and Nicola E. Annels

CXCR4/CXCL12 participate in extravasation of metastasizing breast cancer cells within the liver in a rat model

Wendel, C.; Hemping-Bovenkerk, A.; Krasnyanska, J.; Mees, S.; Kochetkova, M.; Stoeppeler, S.; Haier, J.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em //2012 EN
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INTRODUCTION: Organ-specific composition of extracellular matrix proteins (ECM) is a determinant of metastatic host organ involvement. The chemokine CXCL12 and its receptor CXCR4 play important roles in the colonization of human breast cancer cells to their metastatic target organs. In this study, we investigated the effects of chemokine stimulation on adhesion and migration of different human breast cancer cell lines in vivo and in vitro with particular focus on the liver as a major metastatic site in breast cancer. METHODS: Time lapse microscopy, in vitro adhesion and migration assays were performed under CXCL12 stimulation. Activation of small GTPases showed chemokine receptor signalling dependence from ECM components. The initial events of hepatic colonisation of MDA-MB-231 and MDA-MB-468 cells were investigated by intravital microscopy of the liver in a rat model and under shRNA inhibition of CXCR4. RESULTS: In vitro, stimulation with CXCL12 induced increased chemotactic cell motility (p,0.05). This effect was dependent on adhesive substrates (type I collagen, fibronectin and laminin) and induced different responses in small GTPases, such as RhoA and Rac-1 activation, and changes in cell morphology. In addition, binding to various ECM components caused redistribution of chemokine receptors at tumour cell surfaces. In vivo...

Sphingosine-1-phosphate facilitates trafficking of hematopoietic stem cells and their mobilization by CXCR4 antagonists in mice

Juarez, J.; Harun, N.; Thien, M.; Welschinger, R.; Baraz, R.; Dela Pena, A.; Pitson, S.; Rettig, M.; DiPersio, J.; Bradstock, K.; Bendall, L.
Fonte: Amer Soc Hematology Publicador: Amer Soc Hematology
Tipo: Artigo de Revista Científica
Publicado em //2012 EN
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CXCL12 and VCAM1 retain hematopoietic stem cells (HSCs) in the BM, but the factors mediating HSC egress from the BM to the blood are not known. The sphingosine-1-phosphate receptor 1 (S1P₁) is expressed on HSCs, and S1P facilitates the egress of committed hematopoietic progenitors from the BM into the blood. In the present study, we show that both the S1P gradient between the BM and the blood and the expression of S1P₁ are essential for optimal HSC mobilization by CXCR4 antagonists, including AMD3100, and for the trafficking of HSCs during steady-state hematopoiesis. We also demonstrate that the S1P₁ agonist SEW2871 increases AMD3100-induced HSC and progenitor cell mobilization. These results suggest that the combination of a CXCR4 antagonist and a S1P₁ agonist may prove to be sufficient for mobilizing HSCs in normal donors for transplantation purposes, potentially providing a single mobilization procedure and eliminating the need to expose normal donors to G-CSF with its associated side effects.; Julius G. Juarez, Nadia Harun, Marilyn Thien, Robert Welschinger, Rana Baraz, Aileen Dela Pena, Stuart M. Pitson, Michael Rettig, John F. DiPersio, Kenneth F. Bradstock, and Linda J. Bendall

Novel anti-metastatic action of Cidofovir mediated by inhibition of E6/E7, CXCR4 and Rho/ROCK signaling in HPV+ tumor cells

Amine, Abdessamad; Rivera, Sofia; Opolon, Paule; Dekkal, Mehdi; Biard, Denis S. F.; Bouamar, Hakim; Louache, Fawzia; McKay, Michael J.; Bourhis, Jean; Deutsch, Eric; Vozenin-Brotons, Marie-Catherine
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica Formato: 14 pages
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Cervical cancer is frequently associated with HPV infection. The expression of E6 and E7 HPV oncoproteins is a key factor in its carcinogenicity and might also influence its virulence, including metastatic conversion. The cellular mechanisms involved in metastatic spread remain elusive, but pro-adhesive receptors and their ligands, such as SDF-1alpha and CXCR4 are implicated. In the present study, we assessed the possible relationship between SDF-1alpha/CXCR4 signaling, E6/E7 status and the metastatic process. We found that SDF-1alpha stimulated the invasion of E6/E7-positive cancer cell lines (HeLa and TC-1) in Matrigel though CXCR4 and subsequent Rho/ROCK activation. In pulmonary metastatic foci generated by TC-1 cells IV injection a high proportion of cells expressed membrane-associated CXCR4. In both cases models (in vitro and in vivo) cell adhesion and invasion was abrogated by CXCR4 immunological blockade supporting a contribution of SDF-1alpha/CXCR4 to the metastatic process. E6 and E7 silencing using stable knock-down and the approved anti-viral agent, Cidofovir decreased CXCR4 gene expression as well as both, constitutive and SDF-1alpha-induced cell invasion. In addition, Cidofovir inhibited lung metastasis (both adhesion and invasion) supporting contribution of E6 and E7 oncoproteins to the metastatic process. Finally...

Evaluation of nuclear factor κB and chemokine receptor CXCR4 co-expression in patients with prostate cancer in the Radiation Therapy Oncology Group (RTOG) 8610; Evaluation of nuclear factor kappaB and chemokine receptor CXCR4 co-expression in patients with prostate cancer in the Radiation Therapy Oncology Group (RTOG) 8610

Okera, M.; Bae, K.; Bernstein, E.; Cheng, L.; Lawton, C.; Wolkov, H.; Pollack, A.; Dicker, A.; Sandler, H.; Sweeney, C.
Fonte: Blackwell Publishing Ltd Publicador: Blackwell Publishing Ltd
Tipo: Artigo de Revista Científica
Publicado em //2011 EN
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Objective: To determine the frequency of nuclear factor κB (NFκB) and the chemokine receptor CXCR4 co-expression in prostate cancer specimens from men with locally advanced disease. Patients and Methods: Paraffin-embedded samples from patients enrolled on the Radiation Therapy Oncology Group (RTOG) 8610 trial underwent immunohistochemical staining for NFκB and CXCR4. The amount of NFκB and CXCR4 was scored by a 'blinded' pathologist for the percentage of cells stained (0–100%) and staining intensity (0–3 +). Cox proportional hazard models were used for overall survival and disease-free survival to examine if NFκB and/or CXCR4 expression were associated with patient outcomes with and without adjustment for covariates. Results: Available material and successful staining allowed NFκB and CXCR4 status to be determined for 55 and 63 patients, respectively. Both NFκB and CXCR4 status were available for 51 patients. Of these, 53% were 2/3 + for cytoplasmic NFκB staining and 56% were 2/3 + for CXCR4. In all, 18 of the 51 patients were 2/3 + for both NFκB and CXCR4 (P= 0.129). Ten of 11 patients with 3 + NFκB had 2/3 + CXCR4 (P= 0.004). In this small study, neither NFκB nor CXCR4 were associated with prostate cancer outcomes. Conclusions: High NFκB expression is associated with CXCR4 expression and they are co-expressed in about one third of patients with clinically localized prostate cancer. Larger studies to accurately determine the frequency of co-expression and prognostic utility of NFκB and CXCR4 alone and in combination are warranted.; Meena Okera...

Structure quaternaire des récepteurs de chimiokines CXCR4 et CCR2 et interaction avec leurs effecteurs

Armando, Sylvain
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
FR
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Les récepteurs couplés aux protéines G (RCPG) sont une famille très diversifiée de protéines membranaires capables de répondre à un grand nombre de signaux chimiques tels que des photons, des molécules odorantes, ou des hormones. En plus de cette diversité, l’étude des RCPG montre que des associations protéiques spécifiques multiplient les possibilités de signalisation de chacun de ces récepteurs. En permettant d’atténuer, de potentialiser, ou de générer une nouvelle voie de signalisation, l’association des RCPG en oligomères s’avère une importante source de diversité. L’utilisation du transfert d’énergie de résonance de bioluminescence (BRET) qui permet de détecter les interactions protéiques a révélé de nombreuses associations de RCPG. Durant cette thèse, des outils ont été développés pour combiner efficacement le BRET à des essais de complémentation de protéines (PCA) dans le but de savoir si l’oligomérisation des RCPG pouvait impliquer plus de deux récepteurs. Les résultats présentés montrent que les récepteurs de chimiokines CXCR4 et CCR2 forment des homo et hétéro tétramères, et que l’activation d’un dimère CCR2 peut moduler la conformation d’un dimère CXCR4 par un changement conformationnel trans-récepteur. La coopérativité négative de liaison de ligand qui a été démontrée auparavant entre CXCR4 et CCR2 dans des lymphocytes T CD4+ exprimant les récepteurs de manière endogène confirme la validité biologique de cette interaction. Les données présentées suggèrent également que ces complexes peuvent engager les effecteurs Gαi et β-arrestine2...

Selective enhancement of donor hematopoietic cell engraftment by the CXCR4 antagonist AMD3100 in a mouse transplantation model.

Kang, Y; Chen, BJ; Deoliveira, D; Mito, J; Chao, NJ
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Artigo de Revista Científica Formato: e11316 - ?
Publicado em //2010 ENG; EN_US
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The interaction between stromal cell-derived factor-1 (SDF-1) with CXCR4 chemokine receptors plays an important role in hematopoiesis following hematopoietic stem cell transplantation. We examined the efficacy of post transplant administration of a specific CXCR4 antagonist (AMD3100) in improving animal survival and in enhancing donor hematopoietic cell engraftment using a congeneic mouse transplantation model. AMD3100 was administered subcutaneously at 5 mg/kg body weight 3 times a week beginning at day +2 post-transplant. Post-transplant administration of AMD3100 significantly improves animal survival. AMD3100 reduces pro-inflammatory cytokine/chemokine production. Furthermore, post transplant administration of AMD3100 selectively enhances donor cell engraftment and promotes recovery of all donor cell lineages (myeloid cells, T and B lymphocytes, erythrocytes and platelets). This enhancement results from a combined effect of increased marrow niche availability and greater cell division induced by AMD3100. Our studies shed new lights into the biological roles of SDF-1/CXCR4 interaction in hematopoietic stem cell engraftment following transplantation and in transplant-related mortality. Our results indicate that AMD3100 provides a novel approach for enhancing hematological recovery following transplantation...