196 research outputs found

    The significance of measuring monocyte tissue factor activity in patients with breast and colorectal cancer

    Get PDF
    Monocytes express tissue factor (mTF) in several conditions including cancer where levels may be valuable in assessing tumour presence and progression. Using a two-stage kinetic chromogenic assay (KCA), mTF levels were measured in controls [normal subjects (n = 60) and patients undergoing hernia repair or cholecystectomy (n = 60)], in patients with benign and malignant disease of the breast (n = 83) and of the large bowel (n = 62). This was performed under fresh (resting) conditions and after incubation for 6 h without (unstimulated) and with (stimulated) Escherichia coli endotoxin. The malignant groups showed higher mTF levels than each of the three controls for resting (P < 0.05 breast, P < 0.05 colorectal) unstimulated (P < 0.05 breast, P < 0.05 colorectal) and stimulated cells (P < 0.001 breast, P < 0.01 colorectal). Similarly, the benign inflammatory groups had higher mTF levels than controls for resting (P < 0.05 colorectal), unstimulated (P < 0.05 colorectal) and stimulated cells (P < 0.01 breast, P < 0.01 colorectal). There was no significant difference between malignant and benign inflammatory groups in each organ. mTF levels showed an increase corresponding to that of histological tumour progression and were higher in non-surviving patients. In conclusion, mTF levels are raised in malignant and inflammatory disease compared to controls and patients with non-inflammatory conditions. Stimulated cells give better discrimination between the groups and may be of value in identifying high risk individuals. mTF levels showed an association with tumour grade or stage and the patients' survival time

    Up-regulation of Tissue Factor in Human Pulmonary Artery Endothelial Cells after Ultrafine Particle Exposure

    Get PDF
    BACKGROUND: Epidemiology studies have linked exposure to pollutant particles to increased cardiovascular mortality and morbidity, but the mechanisms remain unknown. OBJECTIVES: We tested the hypothesis that the ultrafine fraction of ambient pollutant particles would cause endothelial cell dysfunction. METHODS: We profiled gene expression of human pulmonary artery endothelial cells (HPAEC) exposed to ultrafine particles (UFPs; 100 μg/mL) from Chapel Hill, North Carolina, or vehicle for 4 hr with Affymetrix HG U133 Plus 2.0 chips (n = 4 each). RESULTS: We found 320 up-regulated genes and 106 down-regulated genes (p < 0.01, 5% false discovery rate). We noted up-regulation of genes related to coagulation [tissue factor (F3) and coagulation factor II receptor-like 2 (F2RL2)] and differential regulation of genes related to F3 signaling (FOS, JUN, and NFKBIA). Results of quantitative polymerase chain reaction show a significant up-regulation of F3 after 10 and 100 μg/mL UFP exposures. Additionally, the water-soluble fractions of UFPs were sufficient to induce the expression of F3, F2RL2, and heme oxygenase 1 (HMOX1). Treatment of HPAEC with UFPs for 16 hr increased the release of interleukin (IL)-6 and IL-8. Pretreatment of HPAEC with a blocking antibody against F3 attenuated IL-6 and IL-8 release by 30 and 70%, respectively. CONCLUSIONS: Using gene profiling, we discovered that UFPs may induce vascular endothelial cells to express genes related to clotting. These results indicate that PM may cause adverse cardiovascular health effects by activating coagulation-inflammation circuitry

    Environments of the Four Tryptophans in the Extracellular Domain of Human Tissue Factor: Comparison of Results from Absorption and Fluorescence Difference Spectra of Tryptophan Replacement Mutants with the Crystal Structure of the Wild-Type Protein

    Get PDF
    The local environments of the four tryptophan residues of the extracellular domain of human tissue factor (sTF) were assessed from difference absorption and fluorescence spectra. The difference spectra were derived by subtracting spectra from single Trp-to-Phe or Trp-to-Tyr replacement mutants from the corresponding spectrum of the wild-type protein. Each of the mutants was capable of enhancing the proteolytic activity of factor Vila showing that the mutations did not introduce major structural changes, although the mutants were more susceptible to denaturation by guanidinium chloride. The difference spectra indicate that the Trp residues are buried to different extents within the protein matrix. This evaluation was compared with the x-ray crystal structure of sTF. There is excellent agreement between predictions from the difference spectra and the environments of the Trp residues observed in the x-ray crystal structure, demonstrating that difference absorption and particularly fluorescence spectra derived from functional single-Trp replacement mutants can be used to obtain information about the local environments of individual Trp residues in multi-tryptophan proteins

    Alterations in myocardial tissue factor expression and cellular localization in dilated cardiomyopathy

    Get PDF
    ObjectivesWe investigated the myocardial localization and expression of tissue factor (TF) and alternatively spliced human tissue factor (asHTF) in patients with dilated cardiomyopathy (DCM).BackgroundTissue factor is expressed in cardiac muscle and may play a role in maintaining myocardial structure.MethodsMyocardial biopsies were obtained from patients with a normal or mildly impaired ejection fraction (EF) (≥50%) and moderate to severely reduced EF (<50%). Explanted DCM hearts were also examined. Myocardial TF expression level was assessed by real-time polymerase chain reaction, TF protein by enzyme-linked immunosorbent assay, and localization by immunohistochemistry.ResultsWe report the identification of asHTF in the human myocardium: it was located in cardiomyocytes and endothelial cells. Quantification of myocardial TF messenger ribonucleic acid in DCM revealed a decrease in the TF/glyceraldehyde-3-phosphate dehydrogenase (GAPDH) ratio (1.76 × 10−1± 6.08 × 10−2for EF ≥50% [n = 19] vs. 1.06 × 10−1± 5.26 × 10−2for EF <50% [n = 27]; p < 0.001) and asHTF/GAPDH ratio (13.91 × 10−5± 11.20 × 10−5for EF ≥50% vs. 7.17 × 10−5± 3.82 × 10−5for EF <50%; p = 0.014). Tissue factor isoform expression level was also decreased in explanted DCM hearts (p < 0.01; n = 12). Total TF protein was reduced by 26% in DCM (p < 0.05). The TF/GAPDH ratio correlated positively with the EF (r = 0.504, p < 0.0001). Immunohistochemistry showed TF localized to the sarcolemma and Z-bands of the cardiomyocytes in patients with normal EF, whereas TF was found in the cardiomyocytic cytosol around the nucleus in DCM.ConclusionsTissue factor was down-regulated in the myocardium of DCM patients. The reduction in TF expression and change in localization may influence cell-to-cell contact stability and contractility, thereby contributing to cardiac dysfunction in DCM

    Expression of tissue factor in non-small-cell lung cancers and its relationship to metastasis

    Get PDF
    Tissue factor (TF) is an initiator of the extrinsic cascade of blood coagulation. Although recent studies have revealed a relationship between metastatic properties and TF expression in some neoplastic cells, the significance of TF in lung cancer, especially in non-small-cell lung cancer (NSCLC), is still unclear. In this study, TF was detected in NSCLC cell lines by functional study, Western blot analysis and immunocytochemical staining. TF levels in eight NSCLC cell lines were also quantitated by enzyme-linked immunosorbent assay (ELISA), and TF expression was evaluated in 55 specimens of surgically resected NSCLCs. NSCLC cell lines derived from metastatic lesions produced high levels of TF (48.3 ± 23.5 ng 10−6 cells, mean ± s.e.m.), whereas those derived from primary lesions produced low levels of TF (0.2 ± 0.1 ng 10−6 cells). Immunohistochemical studies disclosed significantly stronger staining for TF in cells from NSCLC patients with metastasis than in those without metastasis. Among the 28 patients with metastasis, ten were strongly positive, 16 were moderately positive and two were negative for TF. In contrast, among the 27 patients without metastasis, only two were strongly positive, 18 were moderately positive and seven were negative for TF. Therefore, malignant cells from patients with lung cancer produce various levels of TF, and TF may play an important role in the metastatic process. © 1999 Cancer Research Campaig

    Targeting tissue factor on tumour cells and angiogenic vascular endothelial cells by factor VII-targeted verteporfin photodynamic therapy for breast cancer in vitro and in vivo in mice

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The objective of this study was to develop a ligand-targeted photodynamic therapy (tPDT) by conjugating factor VII (fVII) protein with photosensitiser verteporfin in order to overcome the poor selectivity and enhance the effect of non-targeted PDT (ntPDT) for cancer. fVII is a natural ligand for receptor tissue factor (TF) with high affinity and specificity. The reason for targeting receptor TF for the development of tPDT is that TF is a common but specific target on angiogenic tumour vascular endothelial cells (VEC) and many types of tumour cells, including solid tumours and leukaemia.</p> <p>Methods</p> <p>Murine factor VII protein (mfVII) containing a mutation (Lys341Ala) was covalently conjugated via a cross linker EDC with Veterporfin (VP) that was extracted from liposomal Visudyne, and then free VP was separated by Sephadex G50 spin columns. fVII-tPDT using mfVII-VP conjugate, compared to ntPDT, was tested <it>in vitro </it>for the killing of breast cancer cells and VEGF-stimulated VEC and <it>in vivo </it>for inhibiting the tumour growth of breast tumours in a mouse xenograft model.</p> <p>Results</p> <p>We showed that: (i) fVII protein could be conjugated with VP without affecting its binding activity; (ii) fVII-tPDT could selectively kill TF-expressing breast cancer cells and VEGF-stimulated angiogenic HUVECs but had no side effects on non-TF expressing unstimulated HUVEC, CHO-K1 and 293 cells; (iii) fVII targeting enhanced the effect of VP PDT by three to four fold; (iii) fVII-tPDT induced significantly stronger levels of apoptosis and necrosis than ntPDT; and (iv) fVII-tPDT had a significantly stronger effect on inhibiting breast tumour growth in mice than ntPDT.</p> <p>Conclusions</p> <p>We conclude that the fVII-targeted VP PDT that we report here is a novel and effective therapeutic with improved selectivity for the treatment of breast cancer. Since TF is expressed on many types of cancer cells including leukaemic cells and selectively on angiogenic tumour VECs, fVII-tPDT could have broad therapeutic applications for other solid cancers and leukaemia.</p

    Peroxisome Proliferator-Activated Receptor-Gamma Agonists Suppress Tissue Factor Overexpression in Rat Balloon Injury Model with Paclitaxel Infusion

    Get PDF
    The role and underlying mechanisms of rosiglitazone, a peroxisome proliferator-activated receptor-gamma (PPAR-γ) agonist, on myocardial infarction are poorly understood. We investigated the effects of this PPAR-γ agonist on the expression of tissue factor (TF), a primary molecule for thrombosis, and elucidated its underlying mechanisms. The PPAR-γ agonist inhibited TF expression in response to TNF-α in human umbilical vein endothelial cells, human monocytic leukemia cell line, and human umbilical arterial smooth muscle cells. The overexpression of TF was mediated by increased phosphorylation of mitogen-activated protein kinase (MAPK), which was blocked by the PPAR-γ agonist. The effective MAPK differed depending on each cell type. Luciferase and ChIP assays showed that transcription factor, activator protein-1 (AP-1), was a pivotal target of the PPAR-γ agonist to lower TF transcription. Intriguingly, two main drugs for drug-eluting stent, paclitaxel or rapamycin, significantly exaggerated thrombin-induced TF expression, which was also effectively blocked by the PPAR-γ agonist in all cell types. This PPAR-γ agonist did not impair TF pathway inhibitor (TFPI) in three cell types. In rat balloon injury model (Sprague-Dawley rats, n = 10/group) with continuous paclitaxel infusion, the PPAR-γ agonist attenuated TF expression by 70±5% (n = 4; P<0.0001) in injured vasculature. Taken together, rosiglitazone reduced TF expression in three critical cell types involved in vascular thrombus formation via MAPK and AP-1 inhibitions. Also, this PPAR-γ agonist reversed the paclitaxel-induced aggravation of TF expression, which suggests a possibility that the benefits might outweigh its risks in a group of patients with paclitaxel-eluting stent implanted
    • …
    corecore