thromboplastin has been researched along with Cell-Transformation--Neoplastic* in 17 studies
6 review(s) available for thromboplastin and Cell-Transformation--Neoplastic
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Crosstalk between cancer and haemostasis. Implications for cancer biology and cancer-associated thrombosis with focus on tissue factor.
Cancer is characterized by bidirectional interrelations between tumour progression, coagulation activation, and inflammation. Tissue factor (TF), the principal initiator of the coagulation protease cascade, is centrally positioned in this complex triangular network due to its pleiotropic effects in haemostasis, angiogenesis, and haematogenous metastasis. While formation of macroscopic thrombi is the correlate of cancer-associated venous thromboembolism (VTE), a major healthcare burden in clinical haematology and oncology, microvascular thrombosis appears to be critically important to blood-borne tumour cell dissemination. In this regard, expression of TF in malignant tissues as well as shedding of TF-bearing microparticles into the circulation are thought to be regulated by defined genetic events relevant to pathological cancer progression, thus directly linking Trousseau's syndrome to molecular tumourigenesis. Because pharmacological inhibition of the TF pathway in selective tumour types and patient subgroups would be in line with the modern concept of individualized, targeted anti-cancer therapy, this review will focus on the role of TF in tumour biology and cancer-associated VTE. Topics: Animals; Cell Transformation, Neoplastic; Hemostasis; Humans; Models, Biological; Neoplasms; Thromboplastin; Venous Thrombosis | 2012 |
Tissue factor proangiogenic signaling in cancer progression.
Cancer progression from a dormant, non-vascularized benign tumor to metastatic disease is a multiple steps process that critically depends on contributions from the hemostatic system. Tissue factor (TF), protease activated receptors (PARs), factor VIIa, and the endothelial protein C receptor (EPCR) are expressed by tumor cells as well as the host compartment. These components of the hemostatic system regulate tumor growth, angiogenesis and metastasis. Here we review the evidence that TF-dependent signaling is the major driver of primary tumor growth, whereas TF-initiated coagulation and interactions of procoagulant tumor cells with the host compartments initiate multiple pathways that support and regulate the efficiency of metastatic tumor dissemination. Topics: Animals; Blood Coagulation Factors; Cell Transformation, Neoplastic; Humans; Neoplasms; Neovascularization, Pathologic; Signal Transduction; Thromboplastin | 2012 |
Tissue factor and cell signalling in cancer progression and thrombosis.
The close link between coagulation activation and clinical cancer is well established and recent progress has defined underlying molecular pathways by which tumour cells interact with the haemostatic system to promote cancer progression. Tumour type-specific oncogenic transformations cause constitutive and hypoxia-dependent upregulation of tissue factor (TF) in cancer cells, but TF expressed by vascular, stromal and inflammatory cells also contributes to the procoagulant character of the tumour microenvironment. A growing body of genetic and pharmacological evidence implicates signalling by protease activated receptors (PARs) and specifically by tumour cell-expressed TF-VIIa-PAR2 in the induction of an array of proangiogenic and immune modulating cytokines, chemokines and growth factors. Specific inhibition of this pathway results in attenuated tumour growth and angiogenesis. PARs are increasingly recognised as targets for proteases outside the coagulation system and emerging evidence indicates that alternative protease signalling pathways synergise with the coagulation system to promote tumour growth, angiogenesis and metastasis. The elucidation of new therapeutic targets in tumour-promoting protease signalling pathways requires new diagnostic approaches to identify patients that will benefit from tailored therapy targeting procoagulant or signalling aspects of the TF pathway. Topics: Cell Transformation, Neoplastic; Disease Progression; Humans; Models, Molecular; Neoplasms; Peptide Hydrolases; Signal Transduction; Thromboplastin; Thrombosis | 2011 |
Tissue factor and cancer stem cells: is there a linkage?
A common feature in the progression of multiple human malignancies is the protracted deregulation of the coagulation system, often referred to as cancer coagulopathy. Indeed, cancer cells and their vascular stroma often exhibit procoagulant properties, of which deregulation of tissue factor (TF) expression is a notable, although not the sole example. These changes can be traced to oncogenic influences affecting epidermal growth factor receptor (EGFR), EGFRvIII, K-ras, p53, PTEN, and probably many other proto-oncogenes and tumor suppressors in tumor parenchyma. Cancer stem cells (CSCs)/tumor initiating cells (TICs) are thought to represent the primary target and the main cellular effector through which oncogenic mutations exert their tumor-inducing effects. In so doing, CSCs/TICs depend on interactions with the tumor vasculature, which forms supportive niches for their clonal growth. We postulate that TF contributes to these interactions (directly or indirectly) through procoagulant and signaling effects, the latter executed in concert with juxtaposed protease activated receptors (mainly PAR-1 and PAR-2). TF/PAR system acts as a "blood sensing" mechanism, whereby cancer cells, including CSCs/TICs, may respond to plasma proteases (Factors VIIa, Xa, and IIa) and their related microenvironmental changes (fibrin deposition, activation of platelets). A growing body of still largely circumstantial evidence suggests that these events may contribute to the CSC/TIC niche, which could influence tumor initiation, metastasis, recurrence, and therapeutic intractability. Indeed, certain types of cancer cells harboring markers of CSCs (CD133) exhibit elevated TF expression and depend on this receptor to efficiently initiate tumor growth. We propose that both tumor cell-associated and host-related TF could influence the properties of CSCs, and that agents targeting the TF/PAR system may represent a hitherto unappreciated therapeutic opportunity to control cancer progression by influencing the CSC/TIC compartment. Topics: Blood Coagulation; Cell Transformation, Neoplastic; Genes, Tumor Suppressor; Humans; Models, Biological; Neoplasms; Neoplastic Stem Cells; Neovascularization, Pathologic; Oncogenes; Receptors, Proteinase-Activated; Signal Transduction; Thromboplastin | 2009 |
Protease-activated receptors, apoptosis and tumor growth.
Protease-activated receptors (PARs) are G-protein-coupled receptors (GPCRs) that are activated by a unique proteolytic mechanism. Besides the important role of blood coagulation factors in preventing bleeding after vascular injury, these serine proteinases actively engage target cells thereby fulfilling critical functions in cell biology. Cellular responses triggered by coagulation factor-induced PAR activation suggest that PARs play an important role in proliferation, survival and/or malignant transformation of tumor cells. Indeed, PAR expression correlates with cancer malignancy and clinical studies show that anticoagulant treatment is beneficial in cancer patients. In this review, we provide an overview on the PAR family, their mode of activation and mechanisms by which PAR signaling is terminated. In addition, we discuss the relationship between blood coagulation and cancer biology focusing on the potential role of PAR-induced modulation of cell survival, apoptosis and tumor growth. Topics: Amino Acid Sequence; Animals; Apoptosis; Blood Coagulation Factors; Caspases; Cell Division; Cell Transformation, Neoplastic; Conserved Sequence; Enzyme Activation; Heterotrimeric GTP-Binding Proteins; Humans; Mice; Mice, Knockout; Models, Molecular; Molecular Sequence Data; Neoplasm Proteins; Neoplasms; Protein Conformation; Protein Structure, Tertiary; Receptors, Proteinase-Activated; Rhodopsin; Sequence Alignment; Sequence Homology, Amino Acid; Signal Transduction; Thrombophilia; Thromboplastin | 2008 |
Tissue factor and cancer.
Tissue factor (TF), the key regulator of haemostasis and angiogenesis, is also involved in the pathology of several diseases, including cardiovascular, inflammatory and neoplastic conditions. In the latter, TF is upregulated by cancer cells, as well as by certain host cells, and it is the interactions between these distinct pools of TF-expressing cells that likely influence tumour progression in several ways. Furthermore, the release of TF microparticles into the circulation is thought to contribute to the systemic coagulopathies commonly observed in cancer patients. The direct regulation of TF by oncogenic events has provided a plausible explanation for the relatively common overexpression of TF in various cancers and its involvement in tumour growth, angiogenesis, metastasis and coagulopathy. However, this constitutive influence is modified by the tumour microenvironment, cellular interactions and host factors rendering TF expression patterns complex and heterogeneous. It appears that in many biological contexts TF plays a central role in disease progression and thereby potentially constitutes an attractive therapeutic target, especially in scenarios where the risk of bleeding can be avoided by selecting appropriate medications, refined dosing or by targeting the signalling component of TF activity. The efficacy and safety of such approaches still awaits clinical verification. Topics: Animals; Antineoplastic Agents; Blood Coagulation Factors; Blood Platelets; Cell Transformation, Neoplastic; Cell-Derived Microparticles; Drug Delivery Systems; Genes, Tumor Suppressor; Hemostasis; Humans; Mice; Mice, Knockout; Models, Biological; Neoplasm Metastasis; Neoplasm Proteins; Neoplasms; Neovascularization, Pathologic; Oncogenes; Organ Specificity; Platelet Activation; Thrombophilia; Thromboplastin | 2008 |
11 other study(ies) available for thromboplastin and Cell-Transformation--Neoplastic
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Ovulation sources coagulation protease cascade and hepatocyte growth factor to support physiological growth and malignant transformation.
The fallopian tube fimbrial epithelium, which is exposed to the follicular fluid (FF) contents of ovulation, is regarded as the main origin of ovarian high-grade serous carcinoma. Previously, we found that growth factors in FF, such as IGF2, are responsible for the malignant transformation of fallopian tube epithelium. However, ovulation is a monthly transient event, whereas carcinogenesis requires continuous, long-term exposure. Here, we found the transformation activity of FF sustained for more than 30 days after drainage into the peritoneal fluid (PF). Hepatocyte growth factor (HGF), activated through the ovulation injury-tissue factor-thrombin-HGF activator (HGFA)-HGF cleavage cascade confers a sustained transformation activity to fallopian tube epithelium, high-grade serous carcinoma. Physiologically, the high reserve of the coagulation-HGF cascade sources a sustained level of HGF in PF, then to the blood circulation. This HGF axis promotes the growth of the corpus luteum and repair of tissue injury after ovulation. Topics: Adult; Animals; Apoptosis; Cell Proliferation; Cell Transformation, Neoplastic; Cells, Cultured; Corpus Luteum; Cystadenocarcinoma, Serous; Fallopian Tube Neoplasms; Female; Follicular Fluid; Hepatocyte Growth Factor; Humans; Insulin-Like Growth Factor II; Mice; Mice, Inbred NOD; Mice, SCID; Ovarian Neoplasms; Ovulation; Peptide Hydrolases; Prognosis; Serine Endopeptidases; Thrombin; Thromboplastin; Xenograft Model Antitumor Assays | 2021 |
Leukocytes as a reservoir of circulating oncogenic DNA and regulatory targets of tumor-derived extracellular vesicles.
Essentials Tumor-bearing mice were employed to follow oncogenic HRAS sequences in plasma, and blood cells. Cancer DNA accumulated in leukocytes above levels detected in exosomes, platelets and plasma. Extracellular vesicles and nucleosomes are required for uptake of tumor DNA by leukocytes. Uptake of tumor-derived extracellular vesicles by leukocytes triggers coagulant phenotype.. Background Tumor-derived extracellular vesicles (EVs) and free nucleosomes (NSs) carry into the circulation a wealth of cancer-specific, bioactive and poorly understood molecular cargoes, including genomic DNA (gDNA). Objective Here we investigated the distribution of extracellular oncogenic gDNA sequences (HRAS and HER2) in the circulation of tumor-bearing mice. Methods and Results Surprisingly, circulating leukocytes (WBCs), especially neutrophils, contained the highest levels of mutant gDNA, which exceeded the amount of this material recovered from soluble fractions of plasma, circulating EVs, platelets, red blood cells (RBCs) and peripheral organs, as quantified by digital droplet PCR (ddPCR). Tumor excision resulted in disappearance of the WBC-associated gDNA signal within 2-9 days, which is in line with the expected half-life of these cells. EVs and nucleosomes were essential for the uptake of tumor-derived extracellular DNA by neutrophil-like cells and impacted their phenotype. Indeed, the exposure of granulocytic HL-60 cells to EVs from HRAS-driven cancer cells resulted in a selective increase in tissue factor (TF) procoagulant activity and interleukin 8 (IL-8) production. The levels of circulating thrombin-antithrombin complexes (TAT) were markedly elevated in mice harboring HRAS-driven xenografts. Conclusions Myeloid cells may represent a hitherto unrecognized reservoir of cancer-derived, EV/NS-associated oncogenic gDNA in the circulation, and a possible novel platform for liquid biopsy in cancer. In addition, uptake of this material alters the phenotype of myeloid cells, induces procoagulant and proinflammatory activity and may contribute to systemic effects associated with cancer. Topics: Animals; Antithrombin III; Blood Platelets; Breast Neoplasms; Cell Line, Tumor; Cell Survival; Cell Transformation, Neoplastic; DNA, Neoplasm; Exosomes; Extracellular Vesicles; Female; Genes, erbB-2; Genes, ras; Heterografts; HL-60 Cells; Humans; Interleukin-8; Mice; Mice, SCID; Myeloid Cells; Neoplasm Transplantation; Neutrophils; Nucleosomes; Peptide Hydrolases; Plasma; Rats; THP-1 Cells; Thromboplastin; Tumor Burden | 2018 |
The inhibition of pancreatic cancer invasion-metastasis cascade in both cellular signal and blood coagulation cascade of tissue factor by its neutralisation antibody.
Tissue factor (TF), the initiating cell surface receptor for the blood coagulation cascade, plays an important role in malignant transformation of the pancreas, although the precise mechanism remains unresolved. Here, we report that the TF - factor VIIa complex in human pancreatic cancer cells produced a significant amount of MMP-9 and promoted invasion ability in vitro and invasion and metastasis in vivo. For treatment, we successfully developed an anti-human TF monoclonal antibody that inhibits both cellular signalling and blood coagulation cascade via TF. Invasive capability and MMP-9 expression were significantly reduced by the antibody. The antibody inhibited not only tumour invasion in the orthotopic model, but also haematogenous metastasis in the portal-injection liver metastasis model. In conclusion, the TF-VIIa complex plays an important role in invasion-metastasis by enhancing tumour cell infiltration ability and forming microthrombi. The newly established anti-human TF neutralisation antibody may be useful for the treatment of pancreatic and other invasive cancers. Topics: Antibodies, Monoclonal; Blood Coagulation; Cell Transformation, Neoplastic; Factor VIIa; Humans; Neoplasm Invasiveness; Neoplasm Metastasis; Neoplasm Proteins; Pancreatic Neoplasms; Second Messenger Systems; Signal Transduction; Thromboplastin; Tumor Cells, Cultured | 2011 |
Malignant transformation in melanocytes is associated with increased production of procoagulant microvesicles.
Shedding of microvesicles (MVs) by cancer cells is implicated in a variety of biological effects, including the establishment of cancer-associated hypercoagulable states. However, the mechanisms underlying malignant transformation and the acquisition of procoagulant properties by tumour-derived MVs are poorly understood. Here we investigated the procoagulant and prothrombotic properties of MVs produced by a melanocyte-derived cell line (melan-a) as compared to its tumourigenic melanoma counterpart Tm1. Tumour cells exhibit a two-fold higher rate of MVs production as compared to melan-a. Melanoma MVs display greater procoagulant activity and elevated levels of the clotting initiator protein tissue factor (TF). On the other hand, tumour- and melanocyte-derived MVs expose similar levels of the procoagulant lipid phosphatidylserine, displaying identical abilities to support thrombin generation by the prothrombinase complex. By using an arterial thrombosis model, we observed that melanoma- but not melanocyte-derived MVs strongly accelerate thrombus formation in a TF-dependent manner, and accumulate at the site of vascular injury. Analysis of plasma obtained from melanoma-bearing mice showed the presence of MVs with a similar procoagulant pattern as compared to Tm1 MVs produced in vitro. Remarkably, flow-cytometric analysis demonstrated that 60% of ex vivo MVs are TF-positive and carry the melanoma-associated antigen, demonstrating its tumour origin. Altogether our data suggest that malignant transformation in melanocytes increases the production of procoagulant MVs, which may contribute for a variety of coagulation-related protumoural responses. Topics: Animals; Blood Coagulation; Cell Line, Tumor; Cell Transformation, Neoplastic; Cell-Derived Microparticles; Coagulants; Humans; Melanocytes; Melanoma; Mice; Mice, Inbred C57BL; Neoplasm Transplantation; Plasma; Skin Neoplasms; Thrombophilia; Thromboplastin; Thrombosis; Tumor Microenvironment | 2011 |
Oncogenic events regulate tissue factor expression in colorectal cancer cells: implications for tumor progression and angiogenesis.
Tissue factor (TF) is the primary cellular initiator of blood coagulation and a modulator of angiogenesis and metastasis in cancer. Indeed, systemic hypercoagulability in patients with cancer and TF overexpression by cancer cells are both closely associated with tumor progression, but their causes have been elusive. We now report that in human colorectal cancer cells, TF expression is under control of 2 major transforming events driving disease progression (activation of K-ras oncogene and inactivation of the p53 tumor suppressor), in a manner dependent on MEK/mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3'-kinase (PI3K). Furthermore, the levels of cell-associated as well as circulating (microvesicle-associated) TF activity are linked to the genetic status of cancer cells. Finally, RNA interference experiments suggest that TF expression is an important effector of the K-ras-dependent tumorigenic and angiogenic phenotype in vivo. Thus, this study establishes a causal link between cancer coagulopathy, angiogenesis, and genetic tumor progression. Topics: Alleles; Animals; Cell Line, Tumor; Cell Proliferation; Cell Transformation, Neoplastic; Colorectal Neoplasms; Gene Expression Regulation, Neoplastic; Gene Silencing; Genes, p53; Genes, ras; Humans; Mice; Mice, SCID; Mutation; Neoplasm Transplantation; Neovascularization, Pathologic; Thromboplastin | 2005 |
[Effect of panax notoginseng saponin on procoagulant activity and differentiation induction in NB4 cells].
To investigate the effect of Panax notoginseng saponin (PNS) on procoagulant activity (PCA) and differentiation induction in NB4 cells.. After NB4 cells were treated with PNS, the recalcification time, PCA and TF-mRNA expression in NB4 cells were tested by RT-PCR. The inhibitory effect of PNS on NB4 cell proliferation was analysed by MTT method, NBT assay, cell morphological observation and flow cytometry.. (1) PNS of all concentrations could significantly prolong the recalcification time and lower the PCA level in NB4 cells in time-concentration-dependent manner. Simultaneously it down-regulated the expression of TF-mRNA. (2) PNS could partially inhibit the NB4 cell proliferation. (3) PNS could raise the NBT reducing capability of NB4 cells (P < 0.05). And morphological examination showed the differentiating tendency of monocyte and macrophage.. PNS could reduce the procoagulant activity and TF-mRNA expression in NB4 cells, and partially induce the differentiation of NB4 cells, therefore, it is hopeful to be a new anti-coagulant agent. Topics: Antineoplastic Agents; Blood Coagulation Factors; Cell Division; Cell Transformation, Neoplastic; Cysteine Endopeptidases; Humans; Leukemia, Promyelocytic, Acute; Neoplasm Proteins; Panax; Saponins; Thromboplastin; Tumor Cells, Cultured | 2004 |
[hCG-PLZF-RARA transgenic mice develop leukemia resembling human chronic myeloid leukemia].
In order to investigate the leukemogenic potential of PLZF-RARA fusion protein in vivo, hCG-PLZF-RARA transgenic mice were generated, in which PIZF-RARA fusion gene was driven by hCG promoter to express in myeloid cells of mice.. Molecular cloning technology was used to construct hCG-PLZF-RARA gene. The genotype and phenotype of the hCG-PLZF-RARA transgenic mice were analyzed by PCR, RT-PCR, immunofluorescence, morphology of bone marrow (BM) cells, pathology and retinoic acid differentiation assays.. Six hCG-PLZF-RARA transgenic mice developed leukemia resembling human chronic myeloid leukemia. TF(tissue factor) was not expressed in BM cells of normal mice nor in mice without the expressed transgene, but it was expressed in mice expessing the transgene.. PLZF-RARA fusion protein plays a crucial role in leukemogenesis. TF is up-regulated by PLZF-RARA fusion gene. Topics: Animals; Cell Transformation, Neoplastic; Chorionic Gonadotropin; Disease Models, Animal; Humans; Leukemia; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; Mice; Mice, Transgenic; Neoplasm Proteins; Oncogene Proteins, Fusion; Recombinant Fusion Proteins; Thromboplastin; Up-Regulation | 2000 |
Immunohistochemical identification of tissue factor in solid tumors.
Patients with cancer experience a much higher than expected incidence of thromboembolic disorders, commonly referred as Trousseau syndrome. Although this association has been well documented, the etiology of the hypercoagulable state is not known. The expression on tumor cells of tissue factor (TF), a membrane-bound lipoprotein that functions as a cofactor to factor VIIa in the initiation of the extrinsic pathway of blood coagulation, has been postulated as a possible mechanism. Whereas the distribution of TF in normal tissues is known, no large survey of TF expression in malignant tissues has been reported. In this study a polyclonal, monospecific rabbit anti-human TF IgG was used for immunohistochemical localization of TF antigen in 85 different tumor specimens. In general, cell types which normally express TF continued to do so after malignant transformation (41 of 60 epithelial tumor specimens were positive for TF). Tumors of nonepithelial origin frequently lacked TF, with only 3 of 19 specimens containing evidence of TF antigen. In addition five of six benign tumors did not express TF. Many tumor types commonly associated with Trousseau syndrome, for example lung, pancreatic, breast, colon and gastric carcinomas, stained positively for TF. Based on this survey, it appears that TF expression by tumors may be an important factor in the pathogenesis of a hypercoagulable state in some patients with cancer. Topics: Antigens, Neoplasm; Cell Transformation, Neoplastic; Humans; Immunohistochemistry; Neoplasms; Staining and Labeling; Thromboembolism; Thromboplastin | 1992 |
Vascular response in experimental spinal cord gliomas of the rat.
Reported is the immunoreactivity of tumoral and peritumoral vessels of 7 spinal cord gliomas induced in rats by means of ethylnitrosourea. Immunostaining for Factor VIII/RAg has been more strongly pronounced in endothelial cells of newly formed vessels at the tumor periphery, in comparison with tumoral vessels, and this is likely to suggest a differentiation process during extensive neovascularization of the tumor periphery. Endothelial distribution of vimentin in the peripheral vessels is more intensive than within the tumors, suggesting its relation to rapid new blood vessel formation. Immunostaining for GFAP and vimentin overlaps in astrocytes trapped within neoplasms, in astrocytes at the tumor periphery, and in the peritumoral zone. Topics: Animals; Capillaries; Cell Transformation, Neoplastic; Endothelium, Vascular; Female; Glial Fibrillary Acidic Protein; Glioma; Immunohistochemistry; Pregnancy; Rats; Rats, Inbred Strains; Spinal Cord Neoplasms; Thromboplastin; Vimentin | 1988 |
Induction of monocyte-macrophage procoagulant activity by transformed cell lines.
Human peripheral blood monocytes and mature macrophages were found to produce significant procoagulant activity (PCA), identified as tissue factor, on exposure to a variety of human (K562, HL60, Raji) and murine (TU5, NS-1) transformed cell lines. The monocyte procoagulant response was vigorous, generating PCA to a level nearly comparable to the response to endotoxin, a known stimulant for monocyte PCA. The response was rapid and could be fully elicited, in a dose-dependent fashion, within 4 hr with HL60 and Raji cell lines and within 14 hr with K562, TU5, and NS-1 cells. The monocyte PCA-inducing activity was found to reside in the membrane fraction of transformed cells. Other transformed human (Laz 509, Laz 221, Laz 156, U937, CEM) and murine (L1210, P815, TLX9, WEHI 164) cell lines had little, if any, activity. The induction of monocyte PCA by transformed cells most probably was not due to an allogeneic signal, as 1) the K562 and HL60 cell lines were potent PCA inducers despite the lack of class II histocompatibility antigen expression, whereas Laz 156, which did express HLA antigens, was ineffective; 2) mouse peritoneal macrophages responded with the production of strong PCA to the syngeneic transformed cell lines TU5 and NS-1. The monocyte-macrophage procoagulant response to transformed cell lines appeared to be independent of T lymphocytes. Indeed, monocytes purified on the basis of reactivity with monoclonal antibody Mo2 and sorting or depleted of contaminating T cells by anti-T3 antibody and complement responded similarly to conventional monocyte preparations. The production of tissue factor by monocyte-macrophages in response to exposure to some tumor cells may represent a mechanism whereby blood coagulation is activated in malignancy. Topics: Animals; Biological Assay; Blood Coagulation Factors; Cell Line; Cell Membrane; Cell Transformation, Neoplastic; Cells, Cultured; Humans; Lymphocytes; Macrophage Activation; Macrophages; Mice; Monocytes; Thromboplastin | 1986 |
Tissue factor-like activity of the human monocytic tumor cell line U937.
Undisrupted cells of the human monocytic tumor cell line U937 have procoagulant activity that is Ca2+ dependent and is not demonstrable in Factor VII or Factor X deficient plasma. Furthermore, U937 cells when incubated with purified human Factor VII in the presence of Ca2+ and then repeatedly washed promoted coagulation of Factor VII deficient plasma in the absence of added tissue factor. Culture with endotoxin increased the procoagulant activity of U937 cells approximately 5-fold. In separate experiments, exposure to lymphokines obtained from phytohemagglutinin-stimulated lymphocytes enhanced the procoagulant activity of U937 cells 4 to 110-fold. Other cell lines (of myeloid and lymphoid origin) tested lacked the procoagulant activity found in U937 cells. These results indicate that the constitutive tissue factor-like activity of U937 cells resembles that of normal activated human monocytes. Topics: Binding Sites; Blood Coagulation; Blood Coagulation Factors; Cell Line; Cell Transformation, Neoplastic; Endotoxins; Factor VII; Factor VII Deficiency; Factor X Deficiency; Factor XI Deficiency; Humans; Lymphokines; Lymphoma, Large B-Cell, Diffuse; Monocytes; Thromboplastin | 1982 |