LIVIVO - Das Suchportal für Lebenswissenschaften

switch to English language
Erweiterte Suche

Suchergebnis

Treffer 1 - 6 von insgesamt 6

Suchoptionen

  1. Artikel ; Online: Vascular endothelial growth factor in the circulation in cancer patients may not be a relevant biomarker.

    Niers, Tatjana M H / Richel, Dick J / Meijers, Joost C M / Schlingemann, Reinier O

    PloS one

    2011  Band 6, Heft 5, Seite(n) e19873

    Abstract: Background: Levels of circulating vascular endothelial growth factor (VEGF) have widely been used as biomarker for angiogenic activity in cancer. For this purpose, non-standardized measurements in plasma and serum were used, without correction for ... ...

    Abstract Background: Levels of circulating vascular endothelial growth factor (VEGF) have widely been used as biomarker for angiogenic activity in cancer. For this purpose, non-standardized measurements in plasma and serum were used, without correction for artificial VEGF release by platelets activated ex vivo. We hypothesize that "true" circulating (c)VEGF levels in most cancer patients are low and unrelated to cancer load or tumour angiogenesis.
    Methodology: We determined VEGF levels in PECT, a medium that contains platelet activation inhibitors, in citrate plasma, and in isolated platelets in 16 healthy subjects, 18 patients with metastatic non-renal cancer (non-RCC) and 12 patients with renal cell carcinoma (RCC). In non-RCC patients, circulating plasma VEGF levels were low and similar to VEGF levels in controls if platelet activation was minimized during the harvest procedure by PECT medium. In citrate plasma, VEGF levels were elevated in non-RCC patients, but this could be explained by a combination of increased platelet activation during blood harvesting, and by a two-fold increase in VEGF content of individual platelets (controls: 3.4 IU/10(6), non-RCC: 6.2 IU/10(6) platelets, p = 0.001). In contrast, cVEGF levels in RCC patients were elevated (PECT plasma: 64 pg/ml vs. 21 pg/ml, RCC vs. non-RCC, p<0.0001), and not related to platelet VEGF concentration.
    Conclusions: Our findings suggest that "true" freely cVEGF levels are not elevated in the majority of cancer patients. Previously reported elevated plasma VEGF levels in cancer appear to be due to artificial release from activated platelets, which in cancer have an increased VEGF content, during the blood harvest procedure. Only in patients with RCC, which is characterized by excessive VEGF production due to a specific genetic defect, were cVEGF levels elevated. This observation may be related to limited and selective success of anti-VEGF agents, such as bevacizumab and sorafenib, as monotherapy in RCC compared to other forms of cancer.
    Mesh-Begriff(e) Aged ; Biomarkers, Tumor/blood ; Blood Platelets/metabolism ; Case-Control Studies ; Humans ; Middle Aged ; Neoplasms/blood ; Neoplasms/physiopathology ; Platelet Activation ; Platelet Factor 4/metabolism ; Vascular Endothelial Growth Factor A/blood ; beta-Thromboglobulin/metabolism
    Chemische Substanzen Biomarkers, Tumor ; VEGFA protein, human ; Vascular Endothelial Growth Factor A ; beta-Thromboglobulin ; Platelet Factor 4 (37270-94-3)
    Sprache Englisch
    Erscheinungsdatum 2011-05-26
    Erscheinungsland United States
    Dokumenttyp Journal Article
    ISSN 1932-6203
    ISSN (online) 1932-6203
    DOI 10.1371/journal.pone.0019873
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

    Zusatzmaterialien

    Kategorien

  2. Artikel ; Online: Prophylactic plasma levels of the low molecular weight heparin nadroparin does not affect colon cancer tumor development in mouse liver.

    Klerk, Clara P W / Niers, Tatjana M H / Brüggemann, Lois W / Smorenburg, Susanne M / Richel, Dick J / Spek, C Arnold / Van Noorden, Cornelis J F

    Thrombosis research

    2010  Band 125, Heft 3, Seite(n) 235–238

    Mesh-Begriff(e) Animals ; Heparin, Low-Molecular-Weight/therapeutic use ; Mice ; Mice, Inbred C57BL ; Nadroparin/therapeutic use ; Neoplasms/drug therapy
    Chemische Substanzen Heparin, Low-Molecular-Weight ; Nadroparin
    Sprache Englisch
    Erscheinungsdatum 2010-03
    Erscheinungsland United States
    Dokumenttyp Journal Article
    ZDB-ID 121852-9
    ISSN 1879-2472 ; 0049-3848
    ISSN (online) 1879-2472
    ISSN 0049-3848
    DOI 10.1016/j.thromres.2009.03.005
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

    Zusatzmaterialien

    Kategorien

  3. Artikel: Differential effects of anticoagulants on tumor development of mouse cancer cell lines B16, K1735 and CT26 in lung

    Niers, Tatjana M. H / Brüggemann, Lois W / Klerk, Clara P. W / Muller, Femke J. M / Buckle, Tessa / Reitsma, Pieter H / Richel, Dick J / Spek, C. Arnold / Van Tellingen, Olaf / Van Noorden, Cornelis J. F

    Clinical & experimental metastasis. 2009 Mar., v. 26, no. 3

    2009  

    Abstract: Cancer progression is facilitated by blood coagulation. Anticoagulants, such as Hirudin and low molecular weight heparins (LMWHs), reduce metastasis mainly by inhibition of thrombin formation and L- and P-selectin-mediated cell-cell adhesion. It is ... ...

    Abstract Cancer progression is facilitated by blood coagulation. Anticoagulants, such as Hirudin and low molecular weight heparins (LMWHs), reduce metastasis mainly by inhibition of thrombin formation and L- and P-selectin-mediated cell-cell adhesion. It is unknown whether the effects are dependent on cancer cell type. The effects of anticoagulants on tumor development of K1735 and B16 melanoma cells and CT26 colon cancer cells were investigated in mouse lung. Tumor load was determined noninvasively each week up to day 21 in all experiments using bioluminescence imaging. Effects of anticoagulants on tumor development of the three cell lines were correlated with the fibrin/fibrinogen content in the tumors, expression of tissue factor (TF), protease activated receptor (PAR)-1 and -4 and CD24, a ligand of L- and P-selectins. Hirudin inhibited tumor development of B16 cells in lungs completely but did not affect tumor growth of K1735 and CT26 cells. Low molecular weight heparin did not have an effect on K1735 melanoma tumor growth either. TF and PAR-4 expression was similar in the three cell lines. PAR-1 and CD24 were hardly expressed by K1735, whereas CT26 cells expressed low levels and B16 high levels of PAR-1 and CD24. Fibrin content of the tumors was not affected by LMWH. It is concluded that effects of anticoagulants are dependent on cancer cell type and are correlated with their CD24 and PAR-1 expression.
    Sprache Englisch
    Erscheinungsverlauf 2009-03
    Umfang p. 171-178.
    Verlag Springer Netherlands
    Erscheinungsort Dordrecht
    Dokumenttyp Artikel
    ZDB-ID 604952-7
    ISSN 0262-0898
    ISSN 0262-0898
    DOI 10.1007/s10585-008-9227-6
    Datenquelle NAL Katalog (AGRICOLA)

    Zusatzmaterialien

    Kategorien

  4. Artikel ; Online: Endogenous activated protein C limits cancer cell extravasation through sphingosine-1-phosphate receptor 1-mediated vascular endothelial barrier enhancement.

    Van Sluis, Geerte L / Niers, Tatjana M H / Esmon, Charles T / Tigchelaar, Wikky / Richel, Dick J / Buller, Harry R / Van Noorden, Cornelis J F / Spek, C Arnold

    Blood

    2009  Band 114, Heft 9, Seite(n) 1968–1973

    Abstract: Activated protein C (APC) has both anticoagulant activity and direct cell-signaling properties. APC has been reported to promote cancer cell migration/invasion and to inhibit apoptosis and therefore may exacerbate metastasis. Opposing these activities, ... ...

    Abstract Activated protein C (APC) has both anticoagulant activity and direct cell-signaling properties. APC has been reported to promote cancer cell migration/invasion and to inhibit apoptosis and therefore may exacerbate metastasis. Opposing these activities, APC signaling protects the vascular endothelial barrier through sphingosine-1-phosphate receptor-1 (S(1)P(1))activation, which may counteract cancer cell extravasation. Here, we provide evidence that endogenous APC limits cancer cell extravasation, with in vivo use of monoclonal antibodies against APC. The protective effect of endogenous APC depends on its signaling properties. The MAPC1591 antibody that only blocks anticoagulant activity of APC does not affect cancer cell extravasation as opposed to MPC1609 that blocks anticoagulant and signaling properties of APC. Combined administration of anti-APC antibodies and S(1)P(1) agonist (SEW2871) resulted in a similar number of pulmonary foci in mice in presence and absence of APC, indicating that the protective effect of APC depends on the S(1)P(1) pathway. Moreover, endogenous APC prevents cancer cell-induced vascular leakage as assessed by the Evans Blue Dye assay, and SEW2871 treatment reversed MPC1609-dependent vascular leakage. Finally, we show that cancer cells combined with MPC1609 treatment diminished endothelial VE-cadherin expression. In conclusion, endogenous APC limits cancer cell extravasation because of S(1)P(1)-mediated VE-cadherin-dependent vascular barrier enhancement.
    Mesh-Begriff(e) Animals ; Antibodies, Monoclonal/metabolism ; Anticoagulants/chemistry ; Antigens, CD/metabolism ; Cadherins/metabolism ; Endothelium, Vascular/metabolism ; Endothelium, Vascular/pathology ; Evans Blue/pharmacology ; Female ; Melanoma, Experimental ; Mice ; Models, Biological ; Neoplasms/metabolism ; Neoplasms/pathology ; Oxadiazoles/pharmacology ; Protein C/metabolism ; Receptors, Lysosphingolipid/metabolism ; Signal Transduction ; Thiophenes/pharmacology
    Chemische Substanzen Antibodies, Monoclonal ; Anticoagulants ; Antigens, CD ; Cadherins ; Oxadiazoles ; Protein C ; Receptors, Lysosphingolipid ; SEW2871 ; Thiophenes ; cadherin 5 ; Evans Blue (45PG892GO1)
    Sprache Englisch
    Erscheinungsdatum 2009-07-01
    Erscheinungsland United States
    Dokumenttyp Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 80069-7
    ISSN 1528-0020 ; 0006-4971
    ISSN (online) 1528-0020
    ISSN 0006-4971
    DOI 10.1182/blood-2009-04-217679
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

    Zusatzmaterialien

    Kategorien

  5. Artikel ; Online: Differential effects of anticoagulants on tumor development of mouse cancer cell lines B16, K1735 and CT26 in lung.

    Niers, Tatjana M H / Brüggemann, Lois W / Klerk, Clara P W / Muller, Femke J M / Buckle, Tessa / Reitsma, Pieter H / Richel, Dick J / Spek, C Arnold / Van Tellingen, Olaf / Van Noorden, Cornelis J F

    Clinical & experimental metastasis

    2008  Band 26, Heft 3, Seite(n) 171–178

    Abstract: Cancer progression is facilitated by blood coagulation. Anticoagulants, such as Hirudin and low molecular weight heparins (LMWHs), reduce metastasis mainly by inhibition of thrombin formation and L- and P-selectin-mediated cell-cell adhesion. It is ... ...

    Abstract Cancer progression is facilitated by blood coagulation. Anticoagulants, such as Hirudin and low molecular weight heparins (LMWHs), reduce metastasis mainly by inhibition of thrombin formation and L- and P-selectin-mediated cell-cell adhesion. It is unknown whether the effects are dependent on cancer cell type. The effects of anticoagulants on tumor development of K1735 and B16 melanoma cells and CT26 colon cancer cells were investigated in mouse lung. Tumor load was determined noninvasively each week up to day 21 in all experiments using bioluminescence imaging. Effects of anticoagulants on tumor development of the three cell lines were correlated with the fibrin/fibrinogen content in the tumors, expression of tissue factor (TF), protease activated receptor (PAR)-1 and -4 and CD24, a ligand of L- and P-selectins. Hirudin inhibited tumor development of B16 cells in lungs completely but did not affect tumor growth of K1735 and CT26 cells. Low molecular weight heparin did not have an effect on K1735 melanoma tumor growth either. TF and PAR-4 expression was similar in the three cell lines. PAR-1 and CD24 were hardly expressed by K1735, whereas CT26 cells expressed low levels and B16 high levels of PAR-1 and CD24. Fibrin content of the tumors was not affected by LMWH. It is concluded that effects of anticoagulants are dependent on cancer cell type and are correlated with their CD24 and PAR-1 expression.
    Mesh-Begriff(e) Animals ; Anticoagulants/pharmacology ; Anticoagulants/therapeutic use ; Blood Coagulation/drug effects ; CD24 Antigen/metabolism ; Cell Line, Tumor ; Fibrin/metabolism ; Fibrinogen/metabolism ; Heparin, Low-Molecular-Weight/pharmacology ; Heparin, Low-Molecular-Weight/therapeutic use ; Hirudins/pharmacology ; Lung Neoplasms/blood supply ; Lung Neoplasms/drug therapy ; Lung Neoplasms/pathology ; Lung Neoplasms/secondary ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Neoplasm Transplantation ; P-Selectin/metabolism ; Receptor, PAR-1/metabolism ; Thromboplastin/biosynthesis ; Transplantation, Heterologous
    Chemische Substanzen Anticoagulants ; CD24 Antigen ; Heparin, Low-Molecular-Weight ; Hirudins ; P-Selectin ; Receptor, PAR-1 ; Fibrin (9001-31-4) ; Fibrinogen (9001-32-5) ; Thromboplastin (9035-58-9)
    Sprache Englisch
    Erscheinungsdatum 2008-12-10
    Erscheinungsland Netherlands
    Dokumenttyp Journal Article
    ZDB-ID 604952-7
    ISSN 1573-7276 ; 0262-0898
    ISSN (online) 1573-7276
    ISSN 0262-0898
    DOI 10.1007/s10585-008-9227-6
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

    Zusatzmaterialien

    Kategorien

  6. Artikel: Validity of bioluminescence measurements for noninvasive in vivo imaging of tumor load in small animals.

    Klerk, Clara P W / Overmeer, Renée M / Niers, Tatjana M H / Versteeg, Henri H / Richel, Dick J / Buckle, Tessa / Van Noorden, Cornelis J F / van Tellingen, Olaf

    BioTechniques

    2007  Band 43, Heft 1 Suppl, Seite(n) 7–13, 30

    Abstract: A relatively new strategy to longitudinally monitor tumor load in intact animals and the effects of therapy is noninvasive bioluminescence imaging (BLI). The validity of BLIf or quantitative assessment of tumor load in small animals is critically ... ...

    Abstract A relatively new strategy to longitudinally monitor tumor load in intact animals and the effects of therapy is noninvasive bioluminescence imaging (BLI). The validity of BLIf or quantitative assessment of tumor load in small animals is critically evaluated in the present review. Cancer cells are grafted in mice or rats after transfection with a luciferase gene--usually that of a firefly. To determine tumor load, animals receive the substrate agent luciferin intraperitoneally, which luciferase converts into oxyluciferin in an ATP-dependent manner Light emitted by oxyluciferin in viable cancer cells is captured noninvasively with a highly sensitive charge-coupled device (CCD) camera. Validation studies indicate that BLI is useful to determine tumor load in the course of time, with each animal serving as its own reference. BLI is rapid, easy to perform, and sensitive. It can detect tumor load shortly after inoculation, even when relatively few cancer cells (2500-10,000) are used. BLI is less suited for the determination of absolute tumor mass in an animal because of quenching of bioluminescence by tissue components and the exact location of tumors because its spatial resolution is limited. Nevertheless, BLI is a powerful tool for high-throughput longitudinal monitoring of tumor load in small animals and allows the implementation of more advanced orthotopic tumor models in therapy intervention studies with almost the same simplicity as when measuring traditional ectopic subcutaneous models in combination with calipers.
    Mesh-Begriff(e) Animals ; Cell Count/instrumentation ; Cell Count/methods ; Cell Count/trends ; Cell Count/veterinary ; Disease Models, Animal ; Humans ; Luminescent Measurements/instrumentation ; Luminescent Measurements/methods ; Luminescent Measurements/trends ; Luminescent Measurements/veterinary ; Neoplasm Staging/instrumentation ; Neoplasm Staging/methods ; Neoplasm Staging/trends ; Neoplasm Staging/veterinary ; Neoplasms/pathology ; Neoplasms/veterinary
    Sprache Englisch
    Erscheinungsdatum 2007-07
    Erscheinungsland England
    Dokumenttyp Journal Article ; Research Support, Non-U.S. Gov't ; Review ; Validation Studies
    ZDB-ID 48453-2
    ISSN 1940-9818 ; 0736-6205
    ISSN (online) 1940-9818
    ISSN 0736-6205
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

    Zusatzmaterialien

    Kategorien

Zum Seitenanfang