thromboplastin and Neoplasms

Cancer-associated thrombosis (CAT), such as venous thromboembolism (VTE), is a frequent complication in cancer patients, resulting in poor prognosis. Breast cancer is not highly thrombogenic but is highly prevalent, resulting in increased VTE cases. Many cancers express tissue factor (TF), a glycoprotein that triggers coagulation. The cancer cells were shown to express and release substantial amounts of TF-positive microparticles (MPTF), associated with a prothrombotic state. This narrative review evaluated the current use of the procoagulant MPTF as a biomarker for thrombosis risk in breast cancer.. Tumors of epithelial origin with elevated TF expression have been associated with increased VTE incidence. Thus, studies have affirmed the use of MPTF biomarkers for VTE risk in many cancers. Patients with metastatic breast cancer and CAT were found to exhibit elevated procoagulant microparticles in vitro, due to TF expression. The silencing of TF was associated with decreased microparticle release in breast carcinoma cell lines, associated with decreased coagulation.. CAT is a multifactorial condition, with several various underlying diseases. It is proposed that MPTF may be an effective biomarker for thrombosis risk in breast cancer patients but requires a more systemic evaluation utilizing standardized quantification methods.

Topics: Biomarkers; Breast Neoplasms; Cell-Derived Microparticles; Female; Humans; Neoplasms; Thromboplastin; Thrombosis; Venous Thromboembolism

Spontaneous venous thrombosis is often the first clinical sign of cancer, and it is linked to a worsened survival rate. Traditionally, tumor-cell induced platelet activation has been the main actor studied in cancer-associated-thrombosis. However, platelet involvement alone does not seem to be sufficient to explain this heightened pro-thrombotic state. Neutrophils are emerging as key players in both thrombus generation and cancer progression. Neutrophils can impact thrombosis through the release of pro-inflammatory cytokines and expression of molecules like P-selectin and Tissue Factor (TF) on their membrane and on neutrophil-derived microvesicles. Their role in cancer progression is evidenced by the fact that patients with high blood-neutrophil counts have a worsened prognosis. Tumors can attract neutrophils to the cancer site via pro-inflammatory cytokine secretions and induce a switch to pro-tumoral (or N2) neutrophils, which support metastatic spread and have an immunosuppressive role. They can also expel their nuclear contents to entrap pathogens forming Neutrophil Extracellular Traps (NETs) and can also capture coagulation factors, enhancing the thrombus formation. These NETs are also known to have pro-tumoral effects by supporting the metastatic process. Here, we strived to do a comprehensive literature review of the role of neutrophils as drivers of both cancer-associated thrombosis (CAT) and cancer progression.

Topics: Blood Platelets; Extracellular Traps; Humans; Neoplasms; Neutrophils; P-Selectin; Platelet Activation; Thromboplastin; Thrombosis; Venous Thrombosis

Tissue factor (TF), an initiator of extrinsic coagulation pathway, is positively correlated with venous thromboembolism (VTE) of tumor patients. Beyond thrombosis, TF plays a vital role in tumor progression. TF is highly expressed in cancer tissues and circulating tumor cell (CTC), and activates factor VIIa (FVIIa), which increases tumor cells proliferation, angiogenesis, epithelial-mesenchymal transition (EMT) and cancer stem cells(CSCs) activity. Furthermore, TF and TF-positive microvesicles (TF

Topics: Biology; Blood Coagulation; Cell-Derived Microparticles; Factor VIIa; Humans; Neoplasms; Thromboplastin; Thrombosis

Venous and arterial thromboses, called as cancer-associated thromboembolism (CAT), are common complications in cancer patients that are associated with high mortality. The cell-surface glycoprotein tissue factor (TF) initiates the extrinsic blood coagulation cascade. TF is overexpressed in cancer cells and is a component of extracellular vesicles (EVs). Shedding of TF

Topics: Extracellular Vesicles; Humans; Neoplasms; Thromboembolism; Thromboplastin

Disseminated intravascular coagulation (DIC) is a systemic activation of the coagulation system, which results in microvascular thrombosis and, simultaneously, potentially life-threatening haemorrhage attributed to consumption of platelets and coagulation factors. Underlying conditions, e.g. infection, cancer, or obstetrical complications are responsible for the initiation and propagation of the DIC process. This review provides insights into the epidemiology of DIC and the current understanding of its pathophysiology. It details the use of diagnostic biomarkers, current diagnostic recommendations from international medical societies, and it provides an overview of emerging diagnostic and prognostic biomarkers. Last, it provides guidance on management. It is concluded that timely and accurate diagnosis of DIC and its underlying condition is essential for the prognosis. Treatment should primarily focus on the underlying cause of DIC and supportive treatment should be individualised according to the underlying aetiology, patient's symptoms and laboratory records.

Topics: Anticoagulants; Biomarkers; Blood Viscosity; Disease Management; Disseminated Intravascular Coagulation; Endothelium, Vascular; Female; Fibrinolysis; Humans; Male; Neoplasms; Platelet Activation; Pregnancy; Pregnancy Complications, Hematologic; Prevalence; Prognosis; Sepsis; Severity of Illness Index; Thrombin; Thromboembolism; Thromboplastin

The hemostatic cascade is initiated by the transmembrane coagulation protein - tissue factor (TF) and eventuates in fibrin formation. Heparanase protein was demonstrated to directly enhance TF activity resulting in increased activation of the coagulation system. In addition, heparanase was found to increase hemostatic system activation via two other mechanisms: up-regulating TF expression in endothelial cells and releasing the protein tissue factor pathway inhibitor (TFPI) from the cell surface. Peptides derived from TFPI-2, a protein similar to TFPI, were shown to inhibit the TF/heparanase complex as well as attenuate sepsis and tumor growth. Increased heparanase procoagulant activity was observed in several clinical settings, including women using oral contraceptives, women at delivery, patients following orthopedic surgery and patients with diabetic foot, shift work female nurses, patients with lung cancer, retinal vein thrombosis and prosthetic heart valve thrombosis. Remarkably, the heparanase profile was significantly different across the tested groups. Inhibition of TF / heparanase interaction may represent a new target for attenuating coagulation, cancer and inflammation.

Topics: Blood Coagulation; Endothelial Cells; Glucuronidase; Humans; Inflammation; Neoplasms; Thromboplastin

Tissue factor (TF) is the primary initiator of the coagulation cascade, though its effects extend well beyond hemostasis. When TF binds to Factor VII, the resulting TF:FVIIa complex can proteolytically cleave transmembrane G protein-coupled protease-activated receptors (PARs). In addition to activating PARs, TF:FVIIa complex can also activate receptor tyrosine kinases (RTKs) and integrins. These signaling pathways are utilized by tumors to increase cell proliferation, angiogenesis, metastasis, and cancer stem-like cell maintenance. Herein, we review in detail the regulation of TF expression, mechanisms of TF signaling, their pathological consequences, and how it is being targeted in experimental cancer therapeutics.

Topics: Amino Acid Sequence; Cell Hypoxia; Factor VIIa; Gene Expression Regulation, Neoplastic; Humans; Immunotherapy, Adoptive; Integrins; Molecular Sequence Data; Molecular Targeted Therapy; Neoplasm Invasiveness; Neoplasm Metastasis; Neoplasm Proteins; Neoplasms; Neoplastic Stem Cells; Neovascularization, Pathologic; Protein Conformation; Protein Domains; Protein Isoforms; Receptor Protein-Tyrosine Kinases; Receptors, Proteinase-Activated; Signal Transduction; Thrombophilia; Thromboplastin

Topics: Anticoagulants; Betacoronavirus; Coronavirus Infections; COVID-19; Cytokine Release Syndrome; Endothelium, Vascular; Extracellular Traps; Extracellular Vesicles; Fibrinolytic Agents; Hemostasis; Humans; Intermittent Pneumatic Compression Devices; Neoplasms; Pandemics; Pneumonia, Viral; Risk; SARS-CoV-2; Thrombophilia; Thromboplastin; Thrombosis; Venous Thromboembolism

There is a strong relationship between tissue factor (TF) and cancer. Many cancer cells express high levels of both full-length TF and alternatively spliced (as) TF. TF expression in cancer is associated with poor prognosis. In this review, the authors summarize the regulation of TF expression in cancer cells and the roles of TF and asTF in tumor growth and metastasis. A variety of different signaling pathways, transcription factors and micro ribonucleic acids regulate TF gene expression in cancer cells. The TF/factor VIIa complex enhances tumor growth by activating protease-activated receptor 2 signaling and by increasing the expression of angiogenic factors, such as vascular endothelial growth factor. AsTF increases tumor growth by enhancing integrin β1 signaling. TF and asTF also contribute to metastasis via multiple thrombin-dependent and independent mechanisms that include protecting tumor cells from natural killer cells. Finally, a novel anticancer therapy is using tumor TF as a target to deliver cytotoxic drugs to the tumor. TF may be useful in diagnosis, prognosis, and treatment of cancer.

Topics: Gene Expression Regulation, Neoplastic; Humans; Immunoconjugates; Molecular Targeted Therapy; Neoplasm Metastasis; Neoplasms; Prognosis; Signal Transduction; Thromboplastin; Vascular Endothelial Growth Factor A

It has been long-established that cancer and thrombosis are linked, but the exact underlying pathological mechanism remains to be unraveled. As the initiator of the coagulation cascade, the transmembrane glycoprotein tissue factor (TF) has been intensely investigated for its role in cancer-associated thrombosis and cancer progression. TF expression is regulated by both specific oncogenes and environmental factors, and it is shown to regulate primary growth and metastasis formation in a variety of cancer models. In clinical studies, TF has been shown to be overexpressed in most cancer types and is strongly associated with disease progression. While TF clearly associates with cancer progression, a prominent role for TF in the development of cancer-associated thrombosis is less clear. The current concept is that cancer-associated thrombosis is associated with the secretion of tumor-derived TF-positive extracellular vesicles in certain tumor types. To date, many therapeutic strategies to target TF-both in preclinical and clinical phase-are being pursued, including targeting TF or the TF:FVIIa complex by itself or by exploiting TF as a docking molecule to deliver cytotoxic compounds to the tumor. In this review, the authors summarize the current understanding of the role of TF in both cancer progression and cancer-associated thrombosis, and discuss novel insights on TF as a therapeutic target as well as a biomarker for cancer progression and VTE.

Topics: Biomarkers, Tumor; Disease Progression; Extracellular Vesicles; Gene Expression Regulation, Neoplastic; Humans; Neoplasms; Signal Transduction; Thromboplastin; Thrombosis; Venous Thromboembolism

The establishment of prothrombotic states during cancer progression is well reported but the precise mechanisms underlying this process remain elusive. A number of studies have implicated the presence of the clotting initiator protein, tissue factor (TF), in circulating tumor-derived extracellular vesicles (EVs) with thrombotic manifestations in certain cancer types. Tumor cells, as well as tumor-derived EVs, may activate and promote platelet aggregation by TF-dependent and independent pathways. Cancer cells and their secreted EVs may also facilitate the formation of neutrophil extracellular traps (NETs), which may contribute to thrombus development. Alternatively, the presence of polyphosphate (polyP) in tumor-derived EVs may promote thrombosis through a TF-independent route. We conclude that the contribution of EVs to cancer coagulopathy is quite complex, in which one or more mechanisms may take place in a certain cancer type. In this context, strategies that could attenuate the crosstalk between the proposed pro-hemostatic routes could potentially reduce cancer-associated thrombosis.

Topics: Animals; Cell Line, Tumor; Extracellular Traps; Extracellular Vesicles; Humans; Neoplasms; Neutrophils; Platelet Aggregation; Polyphosphates; Thromboplastin; Thrombosis

Cancer induces a systemic hypercoagulable state that elevates the baseline thrombotic risk of affected patients. This hypercoagulable state reflects a complex interplay between cancer cells and host cells and the coagulation system as part of the host response to cancer. Although the tissue factor (TF)/factor VIIa pathway is proposed to be the principal initiator of fibrin formation in cancer patients, clinical studies have not shown a consistent relationship between circulating TF levels (often measured as plasma microvesicle-associated TF) and the risk of thrombosis. A renewed interest in the role of the contact pathway in thrombosis has evolved over the past decade, raising the question of its role in the pathogenesis of thrombotic complications in cancer. Recent observations have documented the presence of activation of the contact system in gastrointestinal, lung, breast and prostate cancers. Although the assays used to measure contact activation differ, and despite the absence of standardization of methodologies, it is clear that both the intrinsic and extrinsic pathways may be activated in cancer. This review will focus on recent findings concerning the role of activation of the contact system in cancer-associated hypercoagulability and thrombosis. An improved understanding of the pathophysiology of these mechanisms may lead to personalized antithrombotic protocols with improved efficacy and safety compared with currently available therapies.

Topics: Animals; Blood Coagulation; Cell-Derived Microparticles; DNA; Factor XII; Fibrin; Glycosaminoglycans; Humans; Neoplasms; Neutrophils; Partial Thromboplastin Time; Platelet Activation; Thromboplastin; Thrombosis

Tissue factor (TF) is the high-affinity receptor and cofactor for factor (F)VII/VIIa. The TF-FVIIa complex is the primary initiator of blood coagulation and plays an essential role in hemostasis. TF is expressed on perivascular cells and epithelial cells at organ and body surfaces where it forms a hemostatic barrier. TF also provides additional hemostatic protection to vital organs, such as the brain, lung, and heart. Under pathological conditions, TF can trigger both arterial and venous thrombosis. For instance, atherosclerotic plaques contain high levels of TF on macrophage foam cells and microvesicles that drives thrombus formation after plaque rupture. In sepsis, inducible TF expression on monocytes leads to disseminated intravascular coagulation. In cancer patients, tumors release TF-positive microvesicles into the circulation that may contribute to venous thrombosis. TF also has nonhemostatic roles. For instance, TF-dependent activation of the coagulation cascade generates coagulation proteases, such as FVIIa, FXa, and thrombin, which induce signaling in a variety of cells by cleavage of protease-activated receptors. This review will focus on the roles of TF in protective hemostasis and pathological thrombosis.

Topics: Animals; Atherosclerosis; Blood Coagulation; Factor IX; Factor VIIa; Factor X; Fibrinolytic Agents; Gene Expression Regulation; Hemostasis; Humans; Neoplasms; Risk Factors; Sepsis; Signal Transduction; Thromboplastin; Thrombosis

The tissue factor (TF) pathway plays a central role in hemostasis and thrombo-inflammatory diseases. Although structure-function relationships of the TF initiation complex are elucidated, new facets of the dynamic regulation of TF's activities in cells continue to emerge. Cellular pathways that render TF non-coagulant participate in signaling of distinct TF complexes with associated proteases through the protease-activated receptor (PAR) family of G protein-coupled receptors. Additional co-receptors, including the endothelial protein C receptor (EPCR) and integrins, confer signaling specificity by directing subcellular localization and trafficking. We here review how TF is switched between its role in coagulation and cell signaling through thiol-disulfide exchange reactions in the context of physiologically relevant lipid microdomains. Inflammatory mediators, including reactive oxygen species, activators of the inflammasome, and the complement cascade play pivotal roles in TF procoagulant activation on monocytes, macrophages and endothelial cells. We furthermore discuss how TF, intracellular ligands, co-receptors and associated proteases are integrated in PAR-dependent cell signaling pathways controlling innate immunity, cancer and metabolic inflammation. Knowledge of the precise interactions of TF in coagulation and cell signaling is important for understanding effects of new anticoagulants beyond thrombosis and identification of new applications of these drugs for potential additional therapeutic benefits.

Topics: Animals; Blood Coagulation; Endothelial Cells; Factor VIIa; Factor Xa; Humans; Inflammation; Myeloid Cells; Neoplasms; Receptor, PAR-2; Signal Transduction; Thromboplastin; Thrombosis

Recent advances in antibody-drug conjugate (ADC) technology have shown considerable promise in targeted cancer therapy. The ADC strategy should be confined to highly toxic anticancer agents and not to ordinary anti-cancer agents (ACAs) because the affinity of monoclonal antibodies (mAbs) diminishes if more than three ACA molecules are conjugated. According to this principle, higher amounts of ADC should be administered so that each of the ACAs is conjugated to the mAbs. Therefore for an ordinary ACA, nanoparticles should be the preferred drug delivery system (DDS). A large body of clinical evidence indicates that abnormal coagulation occurs in a variety of cancer patients, especially in invasive cancers. Tissue factor (TF), expressed on the surface of various cancer cells and tumor vascular endothelial cells, is the trigger protein of extrinsic coagulation resulting in insoluble fibrin formation. We have developed mAbs against TF and human fibrin that reacted only with human fibrin and not with human fibrinogen. We now propose cancer stromal targeting (CAST) therapy and diagnosis, using a cytotoxic agent or radioisotope conjugated to a monoclonal Ab directed at a specific inert constituent of the tumor stroma, as a new modality especially for invasive cancer.

Topics: Antibodies, Monoclonal; Drug Delivery Systems; Fibrin; Humans; Immunoconjugates; Molecular Targeted Therapy; Nanoparticles; Neoplasms; Thromboplastin

The close relationship between cancer and thrombosis is known since more than a century. Venous thromboembolism (VTE) may be the first manifestation of an occult malignancy in an otherwise healthy individual. Cancer patients commonly present with abnormalities of laboratory coagulation tests, indicating an ongoing subclinical hypercoagulable condition. The results of laboratory tests demonstrate that a process of fibrin formation and removal parallels the development of malignancy, which is of particular interest since fibrin and other clotting products are important for both thrombogenesis and tumor progression. Besides general clinical risk factors (i.e. age, previous VTE, immobility, etc.), other factors typical of cancer can increase the thrombotic risk in these patients, including the type of cancer, advanced disease stage, and cancer therapies. In addition, biological factors, including tumor cell-specific prothrombotic properties and the host cell inflammatory response to the tumor, play a central role in the pathogenesis of cancer-associated thrombosis. Cancer cells produce and release procoagulant and fibrinolytic proteins, as well as inflammatory cytokines. In addition, they are capable of directly adhering to host cells (i.e. endothelial cells, monocytes, platelets, and neutrophils), thereby stimulating additional prothrombotic properties of the host effector cells. Tumor-shed procoagulant microparticles also contribute to the patient hypercoagulable state. Finally, the changes of stromal cells of the tumor 'niche' induced by tissue factor (TF) highlight new interactions between hemostasis and cancer. Of interest, most of these mechanisms, besides activating the hemostatic system, also promote tumor growth and metastasis, and are regulated by oncogenic events. Indeed, molecular studies demonstrate that oncogenes responsible for the cellular neoplastic transformation drive the programs of hemostatic protein expression and microparticle liberation by cancer tissues. Human and animal experimental models demonstrate that activation of cancer-associated prothrombotic mechanisms parallels the development of overt thrombotic syndromes in vivo.

Topics: Animals; Cell-Derived Microparticles; Hemostasis; Humans; Neoplasms; Risk Factors; Thromboplastin; Thrombosis

Cancer is associated with an increased risk of venous thromboembolism (VTE); the exact mechanisms for the induction of VTE remain to be fully elucidated, but it is widely acknowledged that tissue factor (TF)-bearing microparticles (TF-MPs) may play a significant role. However, TF-MPs have yet to be accepted as a genuine biomarker for cancer-associated VTE, as the presence of elevated TF-MP levels is not always accompanied by thrombosis; interestingly, in certain cases, particularly in pancreatic cancer, VTE seems to be more likely in the context of acute inflammation. Although several potential mechanisms for the development of VTE in cancer have been postulated, this review explores the homeostatic disruption of TF-MPs, as the main reservoir of bloodborne TF, in the context of cancer and inflammation, and considers the abrogated responses of the activated endothelium and mononuclear phagocyte system in mediating this disruption.

Topics: Biomarkers; Blood Coagulation; Cell-Derived Microparticles; Female; Homeostasis; Humans; Inflammation; Male; Models, Biological; Neoplasms; Phagocytes; Risk Factors; Thromboplastin; Venous Thromboembolism

It is widely recognized that a strong correlation exists between cancer and aberrant hemostasis. Patients with various types of cancers often develop thrombosis, a phenomenon commonly referred to as Trousseau syndrome. Tissue factor (TF) is expressed by tumor cells and contributes to a variety of pathologic processes, such as thrombosis, tumor growth, tumor angiogenesis, and metastasis. Tissue factor is expressed in two naturally occurring protein isoforms: membrane-bound full-length TF (flTF) and soluble alternatively spliced TF (asTF). Tissue factor is the primary initiator of blood coagulation, and it triggers intracellular signaling through protease-activated receptors (PARs). PARs are activated either by TF/FVIIa complexes or by thrombin generated following coagulation activation. Furthermore, the noncoagulant asTF retains an integrin-binding site and stimulates angiogenesis by ligating endothelial integrins αvβ3 and α6β1. Lastly, the increased TF expression in tumors is associated with the release in blood of TF-positive procoagulant microparticles that favor thromboembolic complications. Therefore, the interruption of asTF and flTF signaling represents a potential antiangiogenic strategy. In this review, we summarize the current knowledge on the role of TF in cancer, and we explore therapeutic perspectives based on TF targeting.

Topics: Animals; Biomarkers, Tumor; Forecasting; Humans; Neoplasms; Neovascularization, Pathologic; Thrombophilia; Thromboplastin; Tumor Burden; Vascular Neoplasms

Venous thrombosis is a common complication in cancer patients, and some cancer chemotherapies are associated with an increased risk of venous thromboembolism. The regulatory mechanisms that control thrombus formation and subsequent resolution in patients with cancer, however, are incompletely understood, and novel treatments for cancer-associated thrombosis may arise from a better understanding of such mechanisms. In this chapter, pathways that regulate cancer-associated thrombus formation are outlined, and the effects of anti-angiogenic cancer chemotherapies on venous thrombus resolution are highlighted. Potentially pro-thrombotic effects of anti-angiogenic agents are important considerations when managing the complications of venous thrombosis in cancer patients.

Topics: Angiogenesis Inhibitors; Disease Management; Humans; Neoplasms; Neovascularization, Pathologic; Odds Ratio; Plasminogen Activator Inhibitor 1; Risk; Thromboplastin; Tumor Necrosis Factor-alpha; Venous Thromboembolism; Venous Thrombosis

Induction of thrombosis in tumor vasculature represents an appealing strategy for combating cancer. Formation of fibrin clots may be sufficient to occlude the blood vessels that feed tumor cells, contributing to massive ischemia, vascular infarction, and the subsequent necrosis and apoptosis of neoplastic cells. This approach called as tumor vascular infarction was pioneered by Huang et al. (Science 275:547-550, 1997). Since then, different vascular targeting moieties were linked to a truncated form of human tissue factor (tTF), to generate coaguligands with selective thrombotic activities on tumor neovasculature. In contrast to the wide clinical application of angiogenesis inhibitors and tumor vascular disrupting agents, tTF-NGR is the only example of clinically tested coaguligands. Notably, among these three tumor vascular targeting approaches, tumor vascular infarction is the only modality manifesting long-term curative potential in mice. Translation of this worthy approach has been limited, as induction of thrombosis by TF fusion proteins is leaky. In this review, we describe the clinical significance of tumor vascular infarction, highlight its advantages and disadvantages, and propose a novel strategy for expediting its translation to clinical settings.

Topics: Angiogenesis Inhibitors; Animals; Humans; Mice; Neoplasms; Neovascularization, Pathologic; Thromboplastin; Thrombosis

The hemostatic system is often subverted in patients with cancer, resulting in life-threatening venous thrombotic events. Despite the multifactorial and complex etiology of cancer-associated thrombosis, changes in the expression and activity of cancer-derived tissue factor (TF) - the principle initiator of the coagulation cascade - are considered key to malignant hypercoagulopathy and to the pathophysiology of thrombosis. However, many of the molecular and cellular mechanisms coupling the hemostatic degeneration to malignancy remain largely uncharacterized. In this review we discuss some of the tumor-intrinsic and tumor-extrinsic mechanisms that may contribute to the prothrombotic state of cancer, and we bring into focus the potential for circulating tumor cells (CTCs) in advancing our understanding of the field. We also summarize the current status of anti-coagulant therapy for the treatment of thrombosis in patients with cancer.

Topics: Anticoagulants; Antineoplastic Agents; Blood Coagulation; Blood Platelets; Factor VIIa; Fibrin; Fibrinogen; Gene Expression Regulation, Neoplastic; Humans; Neoplasms; Neoplastic Cells, Circulating; Platelet Activation; Prothrombin; Thromboplastin; Thrombosis

Tissue factor (TF) is an evolutionary conserved glycoprotein that plays an important role in the pathogenesis of cancer. TF is expressed in 2 naturally occurring protein isoforms, membrane-bound full-length (fl)TF and soluble alternatively spliced (as)TF. Both isoforms have been shown to affect a variety of pathophysiologically relevant functions, such as tumor-associated angiogenesis, thrombogenicity, tumor growth, and metastasis. Therefore, targeting TF either by direct inhibition or indirectly, i.e., on a posttranscriptional level, offers a novel therapeutic option for cancer treatment.. In this review we summarize the latest findings regarding the role of TF and its isoforms in cancer biology. Moreover, we briefly depict and discuss the therapeutic potential of direct and/or indirect inhibition of TF activity and expression for the treatment of cancer.. asTF and flTF play important and often distinct roles in cancer biology, i.e., in thrombogenicity and angiogenesis, which is mediated by isoform-specific signal transduction pathways. Therefore, both TF isoforms and downstream signaling are promising novel therapeutic targets in malignant diseases.

Topics: Antibodies, Monoclonal; Antineoplastic Agents; Cell Proliferation; Humans; Neoplasms; Neovascularization, Pathologic; Protein Isoforms; Protein Processing, Post-Translational; Thromboplastin

Thrombosis is a leading cause of morbidity and mortality. Detection of a prothrombotic state using biomarkers would be of great benefit to identify patients at risk of thrombosis that would benefit from thromboprophylaxis. Tissue factor (TF) is a highly procoagulant protein that under normal conditions is not present in the blood. However, increased levels of TF in the blood in the form of microparticles (MPs) (also called extracellular vesicles) are observed under various pathological conditions. In this review, we will discuss studies that have measured MP-TF activity in a variety of diseases using two similar FXa generation assay. One of the most robust signals for MP-TF activity (16-26 fold higher than healthy controls) is observed in pancreatic cancer patients with venous thromboembolism. In this case, the TF+ MPs appear to be derived from the cancer cells. Surprisingly, cirrhosis and acute liver injury are associated with 17-fold and 38-fold increases in MP-TF activity, respectively. Based on mouse models, we speculate that the TF+ MPs are derived from hepatocytes. More modest increases are observed in patients with urinary tract infections (6-fold) and in a human endotoxemia model (9-fold) where monocytes are the likely source of the TF+ MPs. Finally, there is no increase in MP-TF activity in the majority of cardiovascular disease patients. These studies indicate that MP-TF activity may be a useful biomarker to identify patients with particular diseases that have an increased risk of thrombosis.

Topics: Animals; Biomarkers; Blood Coagulation Tests; Cell-Derived Microparticles; Factor Xa; Humans; Neoplasms; Thromboplastin; Thrombosis

Cancer-associated thrombosis remains a significant complication in the clinical management of cancer and interactions of the hemostatic system with cancer biology continue to be elucidated. Here, we review recent progress in our understanding of tissue factor (TF) regulation and procoagulant activation, TF signaling in cancer and immune cells, and the expanding roles of the coagulation system in stem cell niches and the tumor microenvironment. The extravascular functions of coagulant and anti-coagulant pathways have significant implications not only for tumor progression, but also for the selection of appropriate target specific anticoagulants in the therapy of cancer patients.

Topics: Animals; Anticoagulants; Blood Coagulation; Humans; Molecular Targeted Therapy; Neoplasms; Signal Transduction; Thromboplastin; Thrombosis; Tumor Microenvironment

Venous thromboembolism (VTE) and cancer are strongly associated, and present a major challenge in cancer patient treatment. Cancer patients have a higher risk of developing VTE, although the risk differs widely between tumour types. VTE prophylaxis is routinely given to cancer patients, in the form of vitamin K antagonists (VKA) or low molecular weight heparin (LMWH). Several studies have reported that cancer patients receiving anticoagulants show prolonged survival and this effect was more pronounced in patients with a good prognosis, although the mechanism is poorly understood. Tissue Factor (TF) is the initiator of extrinsic coagulation, but its non-haemostatic signalling via protease-activated receptors (PARs) is a potent driver of tumour angiogenesis. Furthermore, coagulation activation is strongly implicated in tumour cell migration and metastasis. This review discusses the effects of anticoagulants on cancer progression in patients, tumour cell behaviour, angiogenesis, and metastasis in in vitro and in vivo models. Inhibition of TF signalling shows great promise in curbing angiogenesis and in vivo tumour growth, but whether this translates to patients is not yet known. Furthermore, non-haemostatic properties of coagulation factors in cancer progression are discussed, which provide exciting opportunities on limiting oncologic processes without affecting blood coagulation.

Topics: Animals; Anticoagulants; Blood Coagulation; Coumarins; Heparin, Low-Molecular-Weight; Humans; Neoplasm Metastasis; Neoplasms; Neovascularization, Pathologic; Signal Transduction; Thromboplastin; Venous Thromboembolism; Vitamin K

Cancer-associated venous thromboembolism (VTE) constitutes the second cause of death after cancer. Many risk factors for cancer-associated VTE have been identified, among them soluble tissue factor and microparticles (MPs). Few data are available about the implication of MPs in cancer associated-VTE through animal model of cancer. The objective of the present review was to report the state of the current literature about MPs and cancer-associated VTE in animal model of cancer. Fourteen series have reported the role of MPs in cancer-associated VTE, through three main mouse models: ectopic or orthotopic tumor induction, experimental metastasis by intravenous injection of tumor cells into the lateral tail vein of the mouse. Pancreatic cancer is the most used animal model, due to its high rate of cancer-associated VTE. All the series reported that tumor cell-derived MPs can promote thrombus formation in TF-dependent manner. Some authors reported also the implication of phosphatidylserine and PSGL1 in the generation of thrombin. Moreover, MPs seem to be implicated in cancer progression through a coagulation-dependent mechanism secondary to thrombocytosis, or a mechanism implicating the regulation of the immune response. For these reasons, few authors have reported that antiplatelet and anticoagulant treatments may prevent tumor progression and the formation of metastases in addition of coagulopathy.

Topics: Animals; Anticoagulants; Blood Coagulation; Cell-Derived Microparticles; Disease Models, Animal; Disease Progression; Humans; Neoplasm Metastasis; Neoplasms; Platelet Aggregation Inhibitors; Risk Factors; Thromboplastin; Thrombosis; Venous Thromboembolism

Heparanase is an endo-β-D-glucuronidase that is capable of cleaving heparan sulfate side chains of heparan sulfate proteoglycans on cell surfaces and the extracellular matrix. This activity is strongly implicated in tumor metastasis and angiogenesis. We have earlier demonstrated that apart of its well characterized enzymatic activity, heparanase may also affect the hemostatic system in a non-enzymatic manner. We showed that heparanase up-regulated the expression of the blood coagulation initiator-tissue factor (TF) and interacted with the tissue factor pathway inhibitor (TFPI) on the cell surface membrane of endothelial and tumor cells, leading to dissociation of TFPI and resulting in increased cell surface coagulation activity. Moreover, we demonstrated that heparanase directly enhanced TF activity, which led to increased factor Xa production and subsequent activation of the coagulation system. In patients with cancer, increased heparanase procoagulant activity appeared to be a potential predictor of survival. We have also shown that JAK-2 is involved in heparanase up-regulation via the erythropoietin receptor, a finding that may point to a new mechanism of thrombosis in JAK-2 positive patents with essential thrombocytosis. Recently, we found that the solvent accessible surface of TFPI-2 first Kunitz domain had a role in TF/heparanase complex inhibition. Peptides derived from TFPI-2 inhibitory site were shown to reduce coagulation activation induced by heparanase and to attenuate sepsis severity and tumor growth in a mouse model, without predisposing to significant bleeding tendency. These data imply that inhibition of heparanase procoagulant domain is potentially a good target for sepsis and cancer therapy.

Topics: Animals; Blood Coagulation; Gene Expression Regulation, Neoplastic; Glucuronidase; Humans; Neoplasms; Polymorphism, Genetic; Thromboplastin

Hypercoagulability is a frequently finding in patients with cancer, and is associated with an increased risk of venous thrombosis (VT). Cancer-associated VT is associated with poor prognosis and represents the leading non-cancer cause of death among these patients. Conversely, patients experiencing VT are at increased risk of subsequent cancer, suggesting an epidemiological bidirectional link between cancer and hemostasis, and indicating a role of the hemostatic system in cancer development. How the coagulation system relates to cancer etiology at the genetic level is largely unexplored. Data on the association of polymorphisms in genes involved in coagulation with cancer development is important to clarify the role of the coagulation system in cancer pathogenesis. Effects of coagulation-related gene polymorphisms on cancer risk may possibly be translated into novel treatment- and prevention strategies of cancer-associated thrombosis and the cancer itself. This article reviews the current knowledge of the relation between polymorphisms in genes involved in coagulation and cancer risk in solid tumors.

Topics: Animals; Blood Coagulation; Factor V; Hemostasis; Humans; Lipoproteins; Neoplasms; Polymorphism, Single Nucleotide; Thromboplastin; Thrombosis

Tissue Factor (TF) is an evolutionary conserved glycoprotein, which is of immense importance for a variety of biologic processes. TF is expressed in two naturally occurring protein isoforms, membrane-bound "full-length" (fl)TF and soluble alternatively spliced (as)TF. The TF isoform expression is differentially modulated on post-transcriptional level via regulatory factors, such as serine/arginine-rich (SR) proteins, SR protein kinases and micro (mi)RNAs. Both isoforms mediate a variety of physiologic- and pathophysiologic-relevant functions, such as thrombogenicity, angiogenesis, cell signaling, tumor cell proliferation and metastasis. In this review, we will depict the main mechanisms regulating the TF isoform expression in cancer and under other pathophysiologic-relevant conditions. Moreover, we will summarize and discuss the latest findings regarding the role of TF and its isoforms in cancer biology.

Topics: Alternative Splicing; Animals; Gene Expression Regulation, Neoplastic; Humans; Neoplasm Invasiveness; Neoplasm Metastasis; Neoplasms; Neovascularization, Pathologic; Protein Isoforms; RNA Interference; RNA Processing, Post-Transcriptional; Signal Transduction; Thromboplastin

Clinically relevant clotting abnormalities in cancer patients are referred to as Trousseau's syndrome. While thrombotic complications such as venous thromboembolism are most frequent in every day's practice, cancer patients may also experience severe bleeding symptoms due to complex systemic coagulopathies, including disseminated intravascular coagulation, haemolytic thrombotic microangiopathy, and hyperfibrinolysis. The pathophysiology of Trousseau's syndrome involves all aspects of Virchow's triad, but previous basic research has mainly focused on the cellular and molecular mechanisms underlying blood hypercoagulability in solid cancers and haematological malignancies. In this regard, over-expression of tissue factor (TF), the principal initiator of the extrinsic coagulation pathway, by primary tumour cells and increased shedding of TF-bearing plasma microparticles are critical to both thrombus formation and cancer progression. However, novel findings on intrinsic contact activation in vivo, such as the release of polyphosphates or DNA by activated platelets and neutrophils, respectively, have pointed to additional pathways in the complex pathophysiology of Trousseau's syndrome.

Topics: Animals; Blood Coagulation Factors; Cell-Derived Microparticles; Factor VIII; Hemostasis; Humans; Models, Cardiovascular; Models, Immunological; Neoplasms; Syndrome; Thromboplastin

Thrombosis is a major cause of morbidity and mortality in cancer patients. Many clinical factors contribute to the high thrombotic risk of this condition, including the type of malignancy, its disease stage, anticancer therapies, and comorbidities. However, the cancer cell-specific prothrombotic properties together with the host cell inflammatory response are important players in the pathogenesis of the cancer-associated hypercoagulability. Tissue factor (TF) is the most important procoagulant protein expressed by cancer cells, and with other cancer tissue procoagulant properties highly contributes to the procoagulant phenotype of malignant cells. Recent discoveries indicate that oncogenes determine the procoagulant protein expression, including TF, in cancer tissues. In addition, in malignancy, TF is also overexpressed by host normal blood cells triggered by cancer-derived inflammatory stimuli. As a consequence, a subclinical activation of blood coagulation is typically present in cancer patients, as demonstrated by abnormalities of circulating thrombotic biomarkers. The relevance of measuring these biomarkers to determine the patient thrombotic risk level is under active investigation. The goal is to identify the high-risk subgroups to establish more accurate and targeted anticoagulation strategies to prevent thrombosis in cancer patients. Ultimately, the clarification of specific molecular mechanisms triggering blood coagulation in specific cancer types may also indicate alternative ways to inhibit clotting activation in these conditions.

Topics: Gene Expression Regulation, Neoplastic; Humans; Neoplasm Proteins; Neoplasms; Thrombophilia; Thromboplastin; Thrombosis

Blood coagulation is one of the most profound factors that influence cancer progression. Especially the initiator of coagulation, tissue factor (TF), has been subject to many studies investigating the overlap between coagulation and cancer. It has been known for decades that TF is a risk factor for metastasis, and in mouse models, TF drives metastasis in a coagulation-dependent manner. However, TF also serves as a cellular receptor to drive primary tumor growth and tumor angiogenesis. Nevertheless, recent studies have indicated that TF plays more fundamental roles in cancer biology. TF regulates tumor cell dormancy, is associated with cancer stem cell behavior, epithelial-to-mesenchymal transition, and dictates establishment of the tumor cell premetastatic niche. Especially with regard to these recent roles attributed to TF, no clear idea exists on the exact molecular pathways that are initiated by TF. Finally, TF alternative splicing results in an isoform with different characteristics and functions in cancer. In this review, a summary will be given on both the established as well as the new aspects of TF function in cancer progression.

Topics: Alternative Splicing; Animals; Blood Coagulation; Gene Expression Regulation, Neoplastic; Humans; Mice; Neoplasm Metastasis; Neoplasm Proteins; Neoplasms; Neoplastic Stem Cells; Neovascularization, Pathologic; Protein Isoforms; Stem Cell Niche; Thromboplastin; Tumor Microenvironment

Tissue factor (TF) is a 47-kDa transmembrane glycoprotein and the main initiator of the blood coagulation cascade. Binding to its ligand factor VIIa (FVIIa) also initiates noncoagulant signaling with broad biological implications. In this review, we discuss how TF interacts with other cell-surface proteins, which affect biological functions such as cell migration and cell survival. A vast number of publications have demonstrated the importance of TF-induced activation of protease-activated receptors, but recently published research has indicated a more complicated picture. As it has been discovered that TF interacts with integrins and receptor tyrosine kinases, novel signaling mechanisms for the TF/FVIIa complex have been presented. The knowledge of these new aspects of TF signaling may, for instance, facilitate the development of new treatment strategies for cancer and acute coronary syndromes, two examples of diseases characterized by aberrant TF expression and signaling.

Topics: Acute Coronary Syndrome; Animals; Apoptosis; Cell Movement; Cell Survival; Factor VIIa; Gene Expression Regulation, Neoplastic; Humans; Neoplasm Proteins; Neoplasms; Protein Binding; Signal Transduction; Thromboplastin

Although many studies have demonstrated that components of the hemostatic system may be involved in signaling leading to cancer progression, the potential mechanisms by which they contribute to cancer dissemination are not yet precisely understood. Among known coagulant factors, tissue factor (TF) and thrombin play a pivotal role in cancer invasion. They may be generated in the tumor microenvironment independently of blood coagulation and can induce cell signaling through activation of protease-activated receptors (PARs). PARs are transmembrane G-protein-coupled receptors (GPCRs) that are activated by a unique proteolytic mechanism. They play important roles in vascular physiology, neural tube closure, hemostasis, and inflammation. All of these agents (TF, thrombin, PARs-mainly PAR-1 and PAR-2) are thought to promote cancer invasion and metastasis at least in part by facilitating tumor cell migration, angiogenesis, and interactions with host vascular cells, including platelets, fibroblasts, and endothelial cells lining blood vessels. Here, we discuss the role of PARs and their activators in cancer progression, focusing on TF- and thrombin-mediated actions. Therapeutic options tailored specifically to inhibit PAR-induced signaling in cancer patients are presented as well.

Topics: Blood Platelets; Endothelial Cells; Enzyme Activation; Humans; Neoplasm Invasiveness; Neoplasm Metastasis; Neoplasms; Neovascularization, Pathologic; Receptor, PAR-1; Receptor, PAR-2; Thrombin; Thromboplastin; Tumor Microenvironment

The aberrant hemostasis is a common manifestation of cancer, and venous thromboembolism (VTE) is the second leading cause of cancer patients' mortality. Tissue factor (TF), comprising of a 47-kDa transmembrane protein that presents in subendothelial tissues and leukocytes and a soluble isoform, have distinct roles in the initiation of extrinsic coagulation cascade and thrombosis. Laboratory and clinical evidence showed the deviant expression of TF in several cancer systems and its tumor-promoting effects. TF contributes to myeloid cell recruitment in tumor stroma, thereby remodeling of tumor microenvironment. Additionally, the number of TF-positive-microparticles (TF+MP) from tumor origins correlates with the VTE rates in cancer patients. In this review, we summarize our current understanding of the TF regulation and roles in tumor progression and clinical complications.

Topics: Animals; Blood Coagulation; Hemostasis; Humans; Neoplasms; Thromboplastin; Tumor Microenvironment; Venous Thromboembolism

Patients with cancer have an increased risk for venous thrombosis. Interestingly, different cancer types have different rates of thrombosis, with pancreatic cancer having one of the highest rates. However, the mechanisms responsible for the increase in venous thrombosis in patients with cancer are not understood. Tissue factor (TF) is a transmembrane receptor and primary initiator of blood coagulation. Tumor cells express TF and spontaneously release TF-positive microparticles (MPs) into the blood. MPs are small membrane vesicles that are highly procoagulant. It has been proposed that these circulating tumor-derived, TF-positive MPs may explain the increased rates of venous thrombosis seen in patients with cancer. In animal models, increased levels of tumor-derived, TF-positive MPs are associated with activation of coagulation. Moreover, these MPs bind to sites of vascular injury and enhance thrombosis. We and others have found that patients with cancer have elevated levels of circulating TF-positive MPs. These MPs are derived from tumors because they express tumor markers and are decreased by tumor resection. Importantly, several studies have shown that increased levels of TF-positive MPs correlate with venous thrombosis in patients with cancer. Taken together, these results suggest that TF-positive MPs may be a useful biomarker to identify patients with cancer who are at high risk for thrombosis.

Topics: Animals; Cell-Derived Microparticles; Humans; Models, Biological; Neoplasms; Risk Factors; Thromboplastin; Venous Thromboembolism; Venous Thrombosis

Tissue factor (TF) is a 47 kDa membrane protein that initiates coagulation by binding to FVII(a) and FX(a) and is a risk factor for thrombosis in many disease states. In addition to its coagulant activity, TF also influences cancer progression by triggering signaling effects via a group of G-protein coupled receptors named protease-activated receptors (PARs). TF localizes to cytoskeletal structures in migrating cells, influences cytoskeleton reorganization and promotes migration. Recently, integrins, important mediators of cell motility, have emerged as important binding partners for TF and influence both TF coagulant and PAR-2-dependent signaling functions. Direct binding of TF to integrins also impacts processes such as cell migration and signaling independent of PAR-2. A recently discovered alternatively spliced, soluble TF isoform also ligates integrins to augment angiogenesis, thus fuelling cancer progression. To date, the literature describes a complex interplay between different integrin subunits and distinct TF isoforms, but our understanding of TF-integrin bidirectional regulation remains clouded. In this review, we aim to summarize the existing knowledge on integrin-TF interaction and speculate on its relevance to physiology and pathology.

Topics: Humans; Integrins; Neoplasms; Thromboplastin; Thrombosis

Cancer is frequently complicated by venous thromboembolic events (VTE), which pose a significant health burden due to the associated high morbidity and mortality rates, yet the exact details of the pathophysiological mechanisms underlying their development are yet to be fully elucidated. Tissue factor (TF), the primary initiator of coagulation, is often overexpressed in malignancy and as such is a prime candidate in predicting the hypercoagulable state. Further exploration of this potential role has identified increases in the number of TF-expressing microparticles (MP) in the circulation of cancer patients, in particular in those known to have high incidences of thromboembolic complications. The risk of VTE in cancer is found to be further elevated by chemotherapy. Chemotherapy may, in eliciting cancer cell apoptosis, result in an increase in release of circulating procoagulant MP. We discuss a potential role of elevated tumour TF expression and increased circulating TF-positive MP in predicting VTE risk.

Topics: Animals; Cell-Derived Microparticles; Humans; Neoplasms; Thromboplastin; Thrombosis; Venous Thromboembolism

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

The interaction of coagulation factors with the perivascular environment affects the development of disease in ways that extend beyond their traditional roles in the acute hemostatic cascade. Key molecular players of the coagulation cascade like tissue factor, thrombin, and fibrinogen are epidemiologically and mechanistically linked with diseases with an inflammatory component. Moreover, the identification of novel molecular mechanisms linking coagulation and inflammation has highlighted factors of the coagulation cascade as new targets for therapeutic intervention in a wide range of inflammatory human diseases. In particular, a proinflammatory role for fibrinogen has been reported in vascular wall disease, stroke, spinal cord injury, brain trauma, multiple sclerosis, Alzheimer's disease, rheumatoid arthritis, bacterial infection, colitis, lung and kidney fibrosis, Duchenne muscular dystrophy, and several types of cancer. Genetic and pharmacologic studies have unraveled pivotal roles for fibrinogen in determining the extent of local or systemic inflammation. As cellular and molecular mechanisms for fibrinogen functions in tissues are identified, the role of fibrinogen is evolving from a marker of vascular rapture to a multi-faceted signaling molecule with a wide spectrum of functions that can tip the balance between hemostasis and thrombosis, coagulation and fibrosis, protection from infection and extensive inflammation, and eventually life and death. This review will discuss some of the main molecular links between coagulation and inflammation and will focus on the role of fibrinogen in inflammatory disease highlighting its unique structural properties, cellular targets, and signal transduction pathways that make it a potent proinflammatory mediator and a potential therapeutic target.

Topics: Alzheimer Disease; Animals; Arthritis, Rheumatoid; Bacterial Infections; Blood Coagulation; Brain Injuries; Colitis; Fibrinogen; Humans; Inflammation; Kidney Diseases; Multiple Sclerosis; Muscular Dystrophy, Duchenne; Neoplasms; Pulmonary Fibrosis; Spinal Cord Injuries; Stroke; Thrombin; Thromboplastin; Vascular Diseases

It is now widely recognized that a strong correlation exists between cancer and aberrant hemostasis. Patients with various types of cancers, including pancreatic, colorectal, and gastric cancer, often develop thrombosis, a phenomenon commonly referred to as Trousseau syndrome. Reciprocally, components from the coagulation cascade also influence cancer progression. The primary initiator of coagulation, the transmembrane receptor tissue factor (TF), has gained considerable attention as a determinant of tumor progression. On complex formation with its ligand, coagulation factor VIIa, TF influences protease-activated receptor-dependent tumor cell behavior, and regulates integrin function, which facilitate tumor angiogenesis both in vitro and in mouse models. Furthermore, evidence exists that an alternatively spliced isoform of TF also affects tumor growth and tumor angiogenesis. In patient material, TF expression and TF cytoplasmic domain phosphorylation correlate with disease outcome in many, but not in all, cancer subtypes, suggesting that TF-dependent signal transduction events are a potential target for therapeutic intervention in selected types of cancer. In this review, we summarize our current understanding of the role of TF in tumor growth and metastasis, and speculate on anticancer therapy by targeting TF.

Topics: Alternative Splicing; Animals; Antineoplastic Agents; Drug Delivery Systems; Factor VIIa; Humans; Integrins; Molecular Targeted Therapy; Neoplasm Proteins; Neoplasms; Neovascularization, Pathologic; Protein Isoforms; Receptor, PAR-2; Signal Transduction; Thromboplastin; Thrombosis

The prevalence of obesity has dramatically increased during the past two decades. Epidemiological studies suggest that obesity is an independent, modifiable risk factor for coronary heart disease, possibly due, at least in part, to the development of a pro-inflammatory and a pro-thrombotic state in obese subjects. In addition, numerous cohort studies have shown a link between obesity and different types of cancer. Accordingly, the regulation of body weight is becoming a serious concern for public health experts and scientists. Although the mechanisms responsible for these associations are still to be fully elucidated, a key role has been assigned to adipokines, a family of hormones which act as modulators of metabolism or inflammation, secreted by adipocytes. Tissue factor, the major physiological trigger of the blood coagulation cascade in vivo, which plays a central role in atherothrombosis and tumor biology, has also been proposed as one of the key molecules responsible for these associations.

Topics: Adipokines; Adipose Tissue; Animals; Atherosclerosis; Blood Coagulation; Humans; Inflammation Mediators; Neoplasms; Obesity; Risk Factors; Signal Transduction; Thromboplastin; Thrombosis

We have taken here the task to go back to a brief history concerning the evolution of the concept of "cancer and thrombosis" according to the experience accumulated by our group in the last 40years. Since its first description by Armand Trousseau in 1865, the association between cancer and thrombosis only received attention again during the last decades of the XXth century: from scattered reports on experimental material (tumor extracts) or on animal models of tumor/metastasis growth, through the progress of cell biology and experimental pharmacology, the interest moved to clinical questions, such as: how to prevent and treat thrombosis, a frequent complication of both solid and hematologic malignancies? Has an occult cancer to be suspected in the majority of cases of idiopathic deep vein thrombosis? Do we need to prevent pharmacologically the occurrence of chemotherapy-associated thrombosis? Do anticoagulants have an impact on the natural history of some tumors? Why antiangiogenetic agents may be associated to a thrombotic risk? Presently, a continuous cross-talk between clinical results and experimental data is required to provide answers to these questions, taking advantage from a multidisciplinary approach to this still partially mysterious issue. If one would take a paradigm of the evolution of the subject during the past 40years, a symbol could be the knowledge accumulated on tissue factor, the "middleman" of the clotting cascade as well as of the interactions between thrombosis and cancer, as briefly reviewed at the end of this chapter.

Topics: Animals; Antineoplastic Agents; Blood Coagulation; Fibrinolytic Agents; History, 20th Century; History, 21st Century; Humans; Neoplasms; Risk Factors; Thromboplastin; Thrombosis

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

Tissue factor (TF), the trigger of blood coagulation, is a 47 kDa membrane protein that also impacts on non-hemostatic processes, such as atherosclerosis, primary tumor growth and metastasis. TF binding to its ligand FVIIa induces activation of protease-activated receptor-2 and this event is thought to considerably influence atherosclerosis and tumor angiogenesis. TF-dependent activation of the coagulation cascade, rather than PAR-2 activation, then leads to the potentiation of metastasis. Importantly, a soluble alternatively spliced isoform of TF (asTF) has been discovered, but the function of asTF in hemostatic and non-hemostatic events is poorly understood. In this review, we aim to present a side-by-side evaluation of normally-spliced, full length TF (flTF) and asTF with regard to coagulant function, atherosclerosis, tumor progression and malignancy-associated thrombosis.

Topics: Blood Coagulation; Hemostatics; Humans; Neoplasms; Protein Isoforms; Thromboplastin; Thrombosis; Treatment Outcome

Coagulation is initiated by tissue factor (TF). Coagulant TF is constitutively expressed by extravascular cells, but there is increasing evidence that TF can also be present within the blood, in particular during pathological conditions. Such TF is exposed on circulating cell-derived vesicles, and its presence has been associated with development of disseminated intravascular coagulation and venous thrombosis. For example, the presence of TF-exposing vesicles in the blood of cancer patients may be associated with their high risk of developing venous thromboembolism. Remarkably, high levels of coagulant TF-exposing vesicles are present in other body fluids such as saliva and urine of healthy persons, suggesting that these vesicles play a physiological role. We postulate that the presence of TF-exposing vesicles in body fluids as saliva and urine provides an additional source of coagulant TF that promotes coagulation, thereby reducing blood loss and contributing to host defence by reducing the risk of microorganisms entering the "milieu intérieur".

Topics: Blood Coagulation; Cell-Derived Microparticles; Humans; Neoplasms; Risk Factors; Saliva; Thromboplastin; Urine; Venous Thromboembolism

The hemostatic system is involved in multiple interactions with transformed cells that progress from a dormant, non-vascularized tumor to highly metastatic phenotypes. Oncogenic transformations up regulate not only the initiator of the coagulation cascade, tissue factor (TF), but also induce other molecules that are required for TF's direct cell signaling activity, including the protease activated receptor (PAR) 2 and factor VIIa. TF-dependent signaling is a major driver for primary tumor progression, whereas TF-initiated coagulation and other components of the hemostatic system support metastasis. Basic research continues to identify pivotal molecular interactions in these processes and provides potential leads for targeting specific tumor promoting pathways associated with hemostasis and thrombosis.

Topics: Animals; Hemostasis; Humans; Neoplasm Invasiveness; Neoplasms; Neovascularization, Pathologic; Signal Transduction; Thromboplastin; Thrombosis

Emerging data have enhanced our understanding of cancer-associated thrombosis, a major cause of morbidity and mortality in patients with cancer. This update will focus on recent findings, including the phenomenon of incidental venous thromboembolism (VTE), novel approaches to risk assessment, and the results of randomized clinical trials focusing on prophylaxis of cancer outpatients. Incidental VTE is an important contributor to rates of cancer-associated VTE and, in terms of outcomes, appears to be as consequential for patients as symptomatic VTE. Multiple biomarkers have been studied, with the highest level of evidence for prechemotherapy elevated platelet counts, elevated leukocyte counts, and low hemoglobin. Other candidate biomarkers, including D-dimer and tissue factor, are currently being evaluated. A recently validated risk score for chemotherapy-associated VTE has now been evaluated in more than 10 000 cancer patients in a variety of clinical settings and trials and is ready for clinical use (Level 1 clinical decision rule). Several randomized clinical trials in solid-tumor patients with low-molecular-weight heparins and semuloparin, an ultra-low-molecular-weight heparin, demonstrate clearly that outpatient thromboprophylaxis is feasible, safe, and effective. Selecting the appropriate patients for prophylaxis, however, continues to be a matter of controversy.

Topics: Anticoagulants; Biomarkers; Cell Count; Fibrin Fibrinogen Degradation Products; Hematology; Humans; Leukocytes; Neoplasms; Outpatients; Randomized Controlled Trials as Topic; Risk; Thromboplastin; Thrombosis; Venous Thromboembolism

Venous thromboembolism (VTE) is a leading cause of morbidity and mortality worldwide. However, the mechanisms by which clots are formed in the deep veins have not been determined. Tissue factor (TF) is the primary initiator of the coagulation cascade and is essential for hemostasis. Under pathological conditions, TF is released into the circulation on small-membrane vesicles termed microparticles (MPs). Recent studies suggest that elevated levels of MP TF may trigger thrombosis. This review provides an overview of the role of TF in VTE.

Topics: Animals; Biomarkers; Blood Coagulation; Cell-Derived Microparticles; Disease Models, Animal; Humans; Mice; Neoplasms; Thromboplastin; Venous Thrombosis; Wounds and Injuries

Cancer and venous thromboembolism are frequently associated.. Venous thromboembolism is associated with a worse prognosis in patients with cancer. Thrombosis in cancer patients is related to the expression of tissue factor and other procoagulants by tumour cells. Surgery, chemotherapy and antiangiogenic agents are also associated with an increased risk of thrombosis. Venous thromboembolism may be the first manifestation of cancer, the risk being especially increased during the first six months following an unexplained episode of idiopathic thrombosis. Current evidence does not suggest that a systematic screening for cancer after an unexplained thrombosis is associated with a clinical benefit. Risk factors for thrombosis specific to the cancer population have been identified. A recent controlled trial suggests that low-molecular weight heparin may reduce the incidence of venous thromboembolism in patients with cancer. These results need to be confirmed. Treatment of venous thromboembolism in cancer patients is primarily based on low-molecular weight heparin administered for three or six months.. Low-molecular weight heparin may increase the survival of patients with cancer through a direct effect on tumour biology. Several clinical trials are underway to confirm this hypothesis.. Thrombosis in cancer patients is a frequent and difficult to treat condition. The role of long-term prophylaxis remains to be defined. The treatment of venous thromboembolism in cancer patients is primarily based on low-molecular weight heparin. Large clinical trials are currently assessing the effect of low-molecular weight heparin on the long-term survival of patients with cancer.

Topics: Administration, Oral; Angiogenesis Inhibitors; Antineoplastic Agents; Combined Modality Therapy; Heparin, Low-Molecular-Weight; Humans; Neoplasms; Neoplastic Cells, Circulating; Postoperative Complications; Prognosis; Pulmonary Embolism; Risk Factors; Thromboplastin; Venous Thromboembolism

Following the molecular cloning of human Tissue Factor (TF) in mid-1980's, great strides have been made in the understanding of TF biology, TF's crucial roles in the initiation of blood coagulation and embryonic development, and TF's contribution to the pathobiology of various disease states. The 21st century brought about a rather unexpected turn in the "TF journey"--a few years back it was reported that the TF gene produces not one, but two proteins with distinct structural and functional characteristics. The so-called "full-length TF" (flTF) - a much-studied integral membrane glycoprotein long presumed to be, and experimentally handled as "the TF" in hundreds of laboratories around the world - is now known to be one of the two TF forms naturally occurring in humans as well as mice. The other, recently discovered form is termed alternatively spliced TF (asTF) which, unlike flTF, lacks a transmembrane domain and can thus be secreted. In this review, we summarize the literature on asTF by discussing asTF's biologic roles as they are currently understood, tackling a number of questions pertaining to asTF's evident and proposed biologic properties, and briefly covering the emerging field of regulated TF pre-mRNA processing.

Topics: Alternative Splicing; Animals; Cardiovascular Diseases; Endothelium, Vascular; Genetic Engineering; Humans; Mice; Mice, Knockout; Mice, Transgenic; Monocytes; Neoplasms; Neovascularization, Physiologic; RNA, Messenger; Thromboplastin

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

Topics: Antineoplastic Agents; Blood Coagulation; Cysteine Endopeptidases; Cytokines; Disseminated Intravascular Coagulation; Fibrinolytic Agents; Humans; Leukemia, Promyelocytic, Acute; Neoplasm Proteins; Neoplasms; Thromboplastin; Tretinoin

Venous thromboembolism (VTE) is common in cancer and is associated with both morbidity and mortality. Erythropoiesis stimulating agents (ESAs) were originally developed to correct anemia. Recent trials in cancer patients however, raise concerns over both increased VTE rates and the possibility of worse tumour outcomes and increased mortality with ESA use. The most common reason offered for explaining the possible negative impact of ESAs on cancer outcomes has been the stimulation of erythropoietin receptors on tumour cells. Despite an extensive literature, it is unlikely that most practicing appreciate the intricate relationship and interaction between the coagulation pathways, angiogenesis and tumour progression and ESA effects. This paper will review these connections and interactions and examine the hypothesis that other mechanisms may underlie the possible negative impact of ESAs on cancer outcomes.

Topics: Anticoagulants; Blood Coagulation; Hematinics; Humans; Neoplasms; Neovascularization, Physiologic; Thromboplastin; Thrombosis; Vascular Endothelial Growth Factor A; Venous Thromboembolism

Venous thromboembolic events (VTE) are a common complication of cancer and its therapy. Prognostic models and biomarkers are currently under investigation as a means to identify cancer patients who are at greatest risk for developing thromboembolic complications and thus are most likely to benefit from primary thromboprophylaxis. Elevations in circulating tissue factor bearing microparticles are associated with thrombosis in cancer patients. We initiated the MicroTEC study which is a randomized, multi-center trial to evaluate the benefit of low molecular weight heparin to prevent VTE in high risk cancer patients. This review details the evidence for tissue factor bearing microparticles in the malignant state and its association with thromboembolic phenomena.

Topics: Anticoagulants; Cell-Derived Microparticles; Heparin, Low-Molecular-Weight; Humans; Multicenter Studies as Topic; Neoplasms; Randomized Controlled Trials as Topic; Thromboplastin; Venous Thromboembolism

Tissue factor (TF) is the key trigger of the coagulation cascade and the membrane signalling receptor for coagulation protease, factor VIIa. In cancer, TF has been implicated in tumor cell survival, growth, and angiogenesis, and is upregulated as a result of oncogenic transformation.. We assayed TF expression and tumourigenicity in mice in the case of human cancer cell lines expressing oncogenic receptor tyrosine kinases. These cells were also subjected to genetic modulation of the kinase suppressor of ras 1 (KSR1), and treated with oncoprotein inhibitors in vitro and in vivo.. Here we show that herceptin, AG1478 and CI-1033, inhibitors of two different members of the ErbB family of oncogenes (HER-2 and EGFR), reduce TF levels in epithelial cancer cells. In EGFR-driven A431 cells, TF upregulation is diminished upon genetic targeting of KSR1, the scaffolding protein involved in EGFR signalling. Conversely, upregulation of KSR1 in A431 cells increases their TF expression and tumourigenicity in mice. The latter property remains dependent on EGFR, as pan-Erb (EGFR) inhibitor, CI-1033, blocks TF promoter activity and inhibits tumour formation by the parental and KSR1 overexpressing A431 cells.. KSR1 emerges, as an important modulator of TF expression in EGFR-driven cancer cells, which also impacts their aggressiveness in vivo.

Topics: Animals; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Factor VIIa; Genes, ras; Humans; Mice; Mice, SCID; Morpholines; Neoplasms; Oncogenes; Phosphotransferases; Quinazolines; Receptor, ErbB-2; Signal Transduction; Thromboplastin; Trastuzumab; Tyrphostins; Up-Regulation

Full-length tissue factor (flTF) initiates coagulation, but also exerts non-hemostatic functions such as inflammation and angiogenesis through protease activated receptors (PARs). In 2003 a soluble variant of flTF was described which results from alternative splicing. Since its discovery the role of alternatively spliced tissue factor (asTF) in coagulation has been debated. asTF may have pro-coagulant properties but due to structural differences when compared to flTF, asTF coagulant function may be relatively low. Nevertheless, similar to flTF, asTF appears to have non-hemostatic properties; asTF expression in tumors correlates with increased tumor size, vessel number and poor survival in some cancer types, and drives tumor growth in animal models. Interestingly, unlike flTF, asTF does not promote angiogenesis through activating PARs but rather via integrin ligation. flTF is a critical determinant in cardiovascular disease but little is known about asTF in cardiovascular disease. asTF is produced by monocytes and macrophages, thus macrophage-derived asTF may contribute to atherosclerotic disease. In conclusion, unraveling asTF's non-hemostatic properties may generate new insights in the pathophysiology and diagnostics of cancer and cardiovascular disease.

Topics: Alternative Splicing; Blood Coagulation; Cardiovascular Diseases; Hemostasis; Humans; Neoplasms; RNA Precursors; Thromboplastin

Glucose-regulated protein 78 (GRP78) is a potential receptor for targeting therapy in cancer and chronic vascular disease due to its overexpression at the cell surface in tumor cells and in atherosclerotic lesions. Presence of the GRP78 autoantibody in cancer patient sera is generally associated with poor prognosis since it signals a prosurvival mechanism in response to cellular stress. Association of GRP78 with various binding partners involves coordination of multiple signaling pathways that result in either cell survival or cell death. Binding of activated alpha2-macroglobulin to cell-surface GRP78 activates Akt to suppress apoptotic pathways through multiple downstream effectors, and concomitantly upregulates NF-kappaBeta and induces the unfolded protein response (UPR) so that cell proliferation prevails. Interaction of GRP78 with cell-surface T-cadherin promotes endothelial cell survival. Association of oncogenic Cripto with GRP78 nullifies TGF-beta superfamily-dependent signaling through Smad2/3 to promote cell proliferation. In contrast, association of GRP78 with the plasminogen kringle 5 domain or extracellular Par-4 promotes apoptosis. Interaction of GRP78 with microplasminogen induces the UPR while association with tissue factor inhibits procoagulant activity. The diverse and multiple binding proteins of GRP78 and their equally diverse functional outcomes reflect the regulatory cellular functions that GRP78 orchestrates. Several GRP78 targeting peptides have been isolated from different tumors and they show remarkable tumor specificity. Conjugation of GRP78-targeting peptides to an apoptosis-inducing peptide suppresses tumor growth in tumor xenografts, thereby demonstrating that GRP78 is a viable target by which clinical cancer therapies can be successfully developed as well as its potential utility in treating vascular disease.

Topics: alpha-Macroglobulins; Apoptosis; Arthritis, Rheumatoid; Autoantibodies; Cadherins; Cell Proliferation; Cell Survival; Endoplasmic Reticulum Chaperone BiP; Heat-Shock Proteins; Humans; Neoplasms; Peptide Fragments; Plasminogen; Receptors, Thrombin; Signal Transduction; Thromboplastin; Unfolded Protein Response; Vascular Diseases

Venous thromboembolism (VTE) is a known complication of cancer which impacts on patient mortality and quality of life. Despite the known deleterious effects of VTE, the benefits of thromboprophylaxis have not been fully established. Identification of patients at highest risk of VTE could lead to better targeting of thromboprophylaxis. Several risk factors have been identified as contributing to VTE such as site and stage of cancer, age, comorbidities, obesity, and acquired prothrombotic states. Anti-cancer agents as well as the use of growth factor support have also been implicated in VTE. Recent data have identified biomarkers such as blood counts, tissue factor and P-selectin. In this review, we briefly summarize the risk factors for VTE as well as candidate biomarkers for VTE in cancer patients. We also review a validated risk score that can identify cancer patients at high risk for VTE. Risk stratification of cancer patients will allow clinicians to identify those patients at highest risk for VTE, who may derive the most benefit from thromboprophylaxis.

Topics: Aged; Factor V; Female; Humans; Infections; Leukocyte Count; Male; Neoplasms; Obesity; P-Selectin; Platelet Count; Risk Factors; Thromboplastin; Venous Thromboembolism

The linkage between activation of the coagulation system and cancer is well established, as is deregulation of tissue factor (TF) by cancer cells, their vascular stroma and cancer-associated inflammatory cells. TF is no longer perceived as an 'alternative' coagulation factor, but rather as a central trigger of the coagulation cascade and an important cell-associated signalling receptor activated by factor VIIa, and interacting with several other regulatory entities, most notably protease-activated receptors (PAR-1 and PAR-2). Preclinical studies revealed the role of oncogenic transformation and tumour micro-environment as TF regulators in cancer, along with the impact of this receptor on gene expression, tumour growth, metastasis, angiogenesis and, possibly, formation of the cancer stem cell niche. Increasing interest surrounds the shedding of TF-containing microvesicles from cancer cells, their entry into the circulation and their role in the intercellular transfer of TF activity, cancer coagulopathy and other processes. Recent data also suggest differential roles of cell autonomous versus global effects of TF in various settings. Questions are raised regarding the consequences of TF expression by tumour cells themselves and by their associated host stroma. Progress in these areas may soon begin to impact on clinical practice and, as such, raises several important questions. Can TF be exploited as a therapeutic target in cancer? Where and when may this be safe and beneficial? Is expression of TF in various disease settings useful as a biomarker of cancer progression or the associated hypercoagulability? What clinical questions related to TF are especially worthy of further exploration, at present and in the near future? Some of these developments and questions will be discussed in this chapter.

Topics: Disease Progression; Humans; Neoplasms; Thromboplastin

Heparanase is an endo-beta-D-glucuronidase capable of cleaving heparan sulphate (HS) side chains of heparan sulphate proteoglycans on cell surfaces and the extracellular matrix; activity that is strongly implicated in tumour metastasis and angiogenesis. It has been shown that heparanase overexpression in human leukaemia, glioma and breast carcinoma cells results in a marked increase in tissue factor (TF) levels. In addition, TF was induced by exogenous addition of recombinant heparanase to tumour cells and primary endothelial cells; induction that was mediated by p38 phosphorylation and correlated with enhanced procoagulant activity. TF induction was further confirmed in transgenic mice overexpressing heparanase, and correlated with heparanase expression levels in leukaemia patients. Heparanase was also found to be involved in the regulation of tissue factor pathway inhibitor (TFPI). It has been shown that heparanase overexpression or exogenous addition induces a two- to three-fold increase in TFPI expression. Similarly, heparanase stimulated accumulation of TFPI in the cell culture medium. However, extracellular accumulation exceeded the observed increase in TFPI at the protein level, and appeared to be independent of HS and heparanase enzymatic activity. Instead, a physical interaction between heparanase and TFPI was demonstrated, suggesting a mechanism by which secreted heparanase interacts with TFPI on the cell surface, leading to dissociation of TFPI from the cell membrane and increased coagulation activity, thus further supporting the local prothrombotic function of heparanase. As heparins are strong inhibitors of heparanase, in view of the effect of heparanase on the TF/TFPI pathway, the role of anticoagulant activity of heparin may potentially be expanded. Taking into account the prometastatic and pro-angiogenic functions of heparanase, its overexpression in human malignancies and abundance in platelets, its involvement in the coagulation machinery is an intriguing novel arena for further research.

Topics: Animals; Blood Coagulation; Disease Progression; Glucuronidase; Humans; Lipoproteins; Neoplasms; Thromboplastin

Topics: Blood Coagulation Disorders; Cell-Derived Microparticles; Endothelium, Vascular; Hemostasis; Humans; Models, Biological; Neoplasm Proteins; Neoplasms; Thrombophilia; Thromboplastin

Topics: Animals; Blood Coagulation Factors; Cell Line, Tumor; Enzyme Activation; Humans; Mice; Neoplasm Proteins; Neoplasms; Thromboembolism; Thrombophilia; Thromboplastin

Topics: Angiogenesis Inhibitors; Blood Coagulation; Blood Coagulation Factors; Blood Platelets; Clinical Trials, Phase II as Topic; Humans; Neoplasm Proteins; Neoplasms; Neovascularization, Pathologic; Neovascularization, Physiologic; Thromboembolism; Thrombophilia; Thromboplastin

Topics: Anticoagulants; Blood Coagulation Factors; Cysteine Endopeptidases; Cytokines; Disseminated Intravascular Coagulation; Fibrinolysis; Humans; Neoplasm Proteins; Neoplasms; Thromboplastin; Venous Thromboembolism

Topics: Anticoagulants; Antineoplastic Agents; Blood Coagulation Factors; Clinical Trials as Topic; Disease Progression; Glucuronidase; Heparin; Heparin, Low-Molecular-Weight; Humans; Neoplasm Metastasis; Neoplasms; Neovascularization, Pathologic; Selectins; Thrombin; Thromboembolism; Thrombophilia; Thromboplastin

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

Tissue factor (TF) is a member of the cytokine receptor superfamily and binds FVII/VIIa. The TF:FVIIa complex has both procoagulant and signaling activities. It functions in many biological processes, including hemostasis, thrombosis, inflammation, angiogenesis and tumor growth. Importantly, TF is essential for hemostasis. However, increased TF expression within atherosclerotic plaques and elevated levels of circulating TF-positive micro particles promote thrombosis. TF increases inflammation by enhancing intravascular fibrin deposition, by increasing the formation of pro-inflammatory fragments of fibrin and by generating coagulation proteases, including FVIIa, FXa and thrombin, that activate protease-activated receptors (PARs). In endotoxemia and sepsis, TF-dependent thrombin generation and activation of PAR1 on dendritic cells enhance inflammation. Finally, the TF:FVIIa complex contributes to tumor growth by activating PAR2.

Topics: Animals; Blood Coagulation Factors; Hemostasis; Humans; Inflammation; Neoplasms; Receptors, Proteinase-Activated; Thromboplastin; Thrombosis

Diverse oncogenic transformations result in the constitutive expression of tissue factor (TF) in cancer cells. The local and systemic activation of the coagulation cascade has long been a recognized hallmark for aggressive cancer, but genetic mouse models and new experimental therapeutics have only recently demonstrated crucial roles for TF initiated cell signaling in the pathogenesis of cancer. On tumor cells, the TF-VIIa binary complex mediates activation of protease activated receptor (PAR) 2 and thereby shapes the tumor microenvironment by inducing an array of proangiogenic and immune modulating cytokines, chemokines, and growth factors. PAR2 also uniquely triggers tumor cell migration by G protein-independent pathways through beta-arrestin scaffolding. Metastatic tumor cells use additional signaling networks of the coagulation cascade by activating PAR1 through thrombin or the ternary TF-VIIa-Xa signaling complex in the vascular and potentially lymphatic system. Selective antagonists of TF-VIIa-PAR2 signaling may be used as antiangiogenic therapy without increasing the risk of bleeding, whereas coagulation and associated signaling pathways on platelets and other host cells may be targeted for therapeutic benefit in advanced cancer and metastatic disease.

Topics: Animals; Blood Coagulation; Factor VIIa; Female; Humans; Male; Mice; Models, Biological; Neoplasm Metastasis; Neoplasms; Receptor, PAR-2; Signal Transduction; Thrombin; Thromboplastin

In 1856 Virchow proposed a triad of causes for venous thrombosis, postulating that stasis, changes in the vessel wall or changes in the blood could lead to thrombosis. We now know that abnormally high levels of some coagulation factors and defects in the natural anticoagulants contribute to thrombotic risk. Among these, factor V Leiden, which renders factor Va resistant to activated protein C, is the most prevalent with approximately 5% of the Caucasian population having this genetic alteration. These genetically controlled variants in coagulation factors work in concert with other risk factors, such as oral contraceptive use, to dramatically increase thrombotic risk. While these abnormalities in the blood coagulation proteins are associated with thrombotic disease propensity, they are less frequent contributors to thrombosis than age or cancer. Cancer increases thrombotic risk by producing tissue factor to initiate coagulation, by shedding procoagulant lipid microparticles or by impairing blood flow. Age is the strongest risk factor for thrombosis. Among possible reasons are fragility of the vessels potentially contributing to stasis, increased coagulation factor levels, impaired function of the venous valves, decreases in the efficacy of natural anticoagulants associated with the vessel wall, increased risk of immobilization and increased risk of severe infection.

Topics: Aging; Blood Coagulation; Factor V; Humans; Neoplasms; Protein C; Thromboplastin; Venous Thrombosis

Patients with cancer are increasingly at risk for venous thromboembolism (VTE). Rates of VTE, however, vary markedly among patients with cancer.. This review focuses on recent data derived from population-based, hospital-based, and outpatient cohort studies of patients with cancer that have identified multiple clinical risk factors as well as candidate laboratory biomarkers predictive of VTE.. Clinical risk factors for cancer-associated VTE include primary tumor site, stage, initial period after diagnosis, presence and number of comorbidities, and treatment modalities including systemic chemotherapy, antiangiogenic therapy, and hospitalization. Candidate predictive biomarkers include elevated platelet or leukocyte counts, tissue factor, soluble P-selectin, and D-dimer. A recently validated risk model, incorporating some of these factors, can help differentiate patients at high or low risk for developing VTE while receiving chemotherapy.. Identifying patients with cancer who are most at risk for VTE is essential to better target thromboprophylaxis, with the eventual goal of reducing the burden as well as the consequences of VTE for patients with cancer.

Topics: Anticoagulants; Antineoplastic Agents; Biomarkers; C-Reactive Protein; Female; Fibrin Fibrinogen Degradation Products; Humans; Male; Neoplasm Staging; Neoplasms; P-Selectin; Prognosis; Risk Assessment; Severity of Illness Index; Survival Analysis; Thromboplastin; Venous Thromboembolism

Tissue factor (TF) is a transmembrane glycoprotein that localizes the coagulation serine protease factor VII/VIIa (FVII/VIIa) to the cell surface. The primary function of TF is to activate the clotting cascade. The TF:FVIIa complex also activates cells by cleavage of a G-protein coupled receptor called protease-activated receptor 2 (PAR2). TF is expressed by tumor cells and contributes to a variety of pathologic processes, such as thrombosis, metastasis, tumor growth, and tumor angiogenesis. For instance, tumor cells release TF-positive procoagulant microparticles into the circulation and these may trigger venous thromboembolism in patients with cancer. TF on circulating tumor cells also leads to the coating of the cells with fibrin that traps them within the microvasculature and facilitates hematogenous metastasis. In addition, TF:FVIIa-dependent activation of PAR2 on tumor cells increases tumor growth via an undefined mechanism. One possibility is that PAR2-dependent signaling increases the expression of proangiogenic proteins. Other studies have reported that endothelial cells in the tumor vasculature express TF and this may enhance angiogenesis. These results suggest that inhibition of TF should reduce several pathologic pathways that increase tumor growth and metastasis. This would represent a novel approach to anticancer therapy. Initial studies using inhibitors of the TF:FVIIa complex in mouse tumor models have produced encouraging results. Nevertheless, additional studies are needed to determine if this strategy can be successfully translated to the treatment of cancer patients.

Topics: Animals; Biomarkers, Tumor; Disease Models, Animal; Disease Progression; Factor VIIa; Female; Humans; Male; Mice; Neoplasm Invasiveness; Neoplasms; Neovascularization, Pathologic; Prognosis; Receptor, PAR-2; Sampling Studies; Severity of Illness Index; Survival Analysis; Thromboplastin; Tumor Burden; Venous Thrombosis

The relationship between hemostasis and malignancy is well recognized, with both elements interacting in a "vicious cycle" where cancers overexpress procoagulants and thrombin, which in turn promote both prothrombotic potential and tumor growth, invasion, and spread. Indeed, venous thromboembolism, particularly idiopathic venous thrombosis, occurs frequently as a paraneoplastic phenomenon, and in turn several components of primary and secondary hemostasis (namely platelets, tissue factor, and thrombin) play an important role in primary tumor growth and metastasization. Despite the many and various mechanisms involved in this multifaceted relationship, anticoagulants might represent an attractive anticancer therapy, in that current research supports the hypothesis that such drugs may offer a better control of cancer progression. The main biological and clinical evidence on the relationship between cancer and hemostasis are briefly summarized in this review, as is the potential benefits of anticoagulant therapy in this setting.

Topics: Animals; Anticoagulants; Blood Coagulation; Hemostasis; Humans; Neoplasms; Platelet Activation; Thrombin; Thromboplastin; Venous Thromboembolism

The activation of the coagulation cascade in the tumor microenvironment is a key feature of advanced malignancies. On tumor cells, tissue factor (TF) plays a central role to initiate cross-talk through the release of procoagulant microparticles or through direct, protease-activated receptor (PAR)-mediated cell signaling that leads to the production of soluble cytokines and angiogenic growth factors. In addition, the hemostatic system in the host compartment sustains crucial circuits that promote metastasis and support tumor growth and angiogenesis. Experimental tumor and genetic models have defined specific pathways that are supported by tumor cell and host TF and have identified potential therapeutic modalities to specifically interrupt TF signaling in tumor biology without impairment of hemostatic functions.

Topics: Animals; Anticoagulants; Blood Coagulation; Colorectal Neoplasms; Disease Progression; Factor VIIa; Humans; Mice; Neoplasm Metastasis; Neoplasms; Receptor, PAR-1; Receptor, PAR-2; Signal Transduction; Thromboplastin

Oncogenic upregulation of tissue factor (TF) and release of TF-containing microvesicles play an important role in cancer-related coagulopathy (Trousseau's syndrome), angiogenesis, and disease progression. In addition, certain types of host cells (stromal cells, inflammatory cells, activated endothelium) may also express TF. Although the relative contribution of host-related versus tumor-related TF to tumor progression is not known, our recent studies indicate that the role of both sources of TF in tumor formation is complex and context-dependent. Disruption of TF expression/activity in cancer cells leads to tumor growth inhibition in immunodeficient mice, even in cases where TF overexpression is driven by potent oncogenes ( K-RAS or EGFR). Interestingly, TF expression in vivo appears to be influenced by many factors, including the level of oncogenic transformation, tumor microenvironment, and differentiation from cancer stem-like cells. We postulate that activation of TF signaling and coagulation may deliver growth-promoting stimuli (e.g., fibrin, thrombin, platelets) to dormant cancer stem cells (CSCs). Functionally, these influences may be tantamount to formation of a provisional (TF-dependent) cancer stem cell niche. As such, these changes may contribute to the involvement of CSCs in tumor growth, angiogenesis, and metastasis.

Topics: Blood Coagulation Disorders; Disease Progression; Neoplasms; Neovascularization, Pathologic; Oncogenes; Thromboplastin; Up-Regulation

Tissue factor (TF) is the primary initiator of the coagulation cascade and plays an essential role in hemostasis. TF also contributes to many diseases, including cancer. The correlation between thrombosis and cancer has been recognized for more than a century. However, it is only in the past two decades that we have begun to understand the role of TF in tumor biology. TF expression is upregulated on both tumor and host cells in cancer patients as well as in the circulation. Clinical observations indicate a direct correlation between the levels of tumor cell TF expression and poor prognosis for cancer patients. The role of TF in tumor biology has been extensively studied using various mouse tumor models. It has been demonstrated that tumor cell TF contributes to tumor metastasis, growth, and angiogenesis. The role of host TF in tumor progression is less clear. Recently developed mouse models with altered levels of TF may be useful in further analysis of the role of host cell TF in cancer.

Topics: Animals; Disease Models, Animal; Mice; Neoplasm Metastasis; Neoplasm Transplantation; Neoplasms; Neovascularization, Pathologic; Thromboplastin; Up-Regulation

Blood-borne tissue factor (TF)-bearing microparticles have been shown to play an important role in thrombus propagation in experimental models. The pathophysiologic role of these microparticles is being investigated in several prothrombotic conditions including cancer-associated thrombosis. Tumor cells are known to shed TF-bearing microparticles in vitro, and circulating TF-bearing microparticles can be measured in plasma samples from patients with advanced cancer. We are currently using an impedance-based flow cytometer to accurately size and enumerate TF-bearing microparticles to explore the association between cancer thrombosis and elevations in circulating TF-bearing microparticles.

Topics: Blood Coagulation; Blood Platelets; Cell Membrane Structures; Flow Cytometry; Humans; Neoplasms; Particle Size; Thromboplastin; Thrombosis

Heparanase is an endo-beta- D-glucuronidase that is capable of cleaving heparan sulfate side chains of heparan sulfate proteoglycans on cell surfaces and the extracellular matrix, activity that is strongly implicated in tumor metastasis and angiogenesis. Evidence was provided that heparanase overexpression in human leukemia, glioma, and breast carcinoma cells results in a marked increase in tissue factor (TF) levels. Likewise, TF was induced by exogenous addition of recombinant heparanase to tumor cells and primary endothelial cells, induction that was mediated by p38 phosphorylation and correlated with enhanced procoagulant activity. TF induction was further confirmed in heparanase-overexpressing transgenic mice and correlated with heparanase expression levels in leukemia patients. Heparanase was also found to be involved in the regulation of tissue factor pathway inhibitor (TFPI). It was shown that heparanase overexpression or exogenous addition induces two- to threefold increase of TFPI expression. Similarly, heparanase stimulated accumulation of TFPI in the cell culture medium. Extracellular accumulation exceeded, however, the observed increase in TFPI at the protein level and appeared to be independent of heparan sulfate and heparanase enzymatic activity. Instead, a physical interaction between heparanase and TFPI was demonstrated, suggesting a mechanism by which secreted heparanase interacts with TFPI on the cell surface, leading to dissociation of TFPI from the cell membrane and increased coagulation activity, thus further supporting the local prothrombotic function of heparanase. As heparins are strong inhibitors of heparanase, in view of the effect of heparanase on TF/TFPI pathway, the role of heparins' anticoagulant activity may potentially be expanded.

Topics: Breast Neoplasms; Cell Line, Tumor; Endothelial Cells; Glucuronidase; Heparin; Humans; Lipoproteins; Neoplasm Metastasis; Neoplasms; Neovascularization, Pathologic; Thromboplastin

Tissue factor is increasingly viewed as an integral part of the vicious circle that links the vascular system with cancer progression at multiple systemic, cellular and molecular levels.. The emerging tenet in this area is that oncogenic events/pathways driving the malignant process also stimulate the expression of tissue factor by cancer cells and promote the release of tissue factor-containing microvesicles into the circulation. The combined effects of these changes likely contribute to cancer coagulopathy, cessation of tumour dormancy, aggressive growth, angiogenesis and metastasis, notably through a combination of procoagulant and signalling effects set in motion by tissue factor. As certain tumour-associated host cell types (inflammatory cells, endothelium) may also express tissue factor their contribution is plausible, though poorly understood. Interestingly, tissue factor could be 'shared' between various subsets of cancer and host cells due to intercellular transfer of tissue factor-containing microvesicles. It has recently been proposed that tissue factor may influence the interactions between tumour initiating (stem) cells and their growth or prometastatic niches.. Whereas targeting tissue factor in cancer is appealing, the prospects in this regard will depend on the identification of disease specific indications, active agents and their safe regimens.

Topics: Cell Proliferation; Humans; Neoplasms; Neovascularization, Pathologic; Thromboplastin

The clinical link between cancer and thrombosis has been recognized by Armand Trousseau in 1865. It has now become clear that clotting activation in malignancy not only plays an important role in the evolution of venous thromboembolism (VTE) or systemic coagulation disorders such as disseminated intravascular coagulation, but that multiple components of the haemostatic and fibrinolytic systems are directly involved in tumour progression. In particular, tissue factor (TF) appears to be involved in several pathways relevant to cancer growth and metastasis. Increasing evidence emerges that haemostatic perturbances in cancer patients are, at least in part, controlled by defined genetic events in molecular tumourigenesis including activating and inactivating mutations of oncogenes and tumour suppressor genes, respectively. Long-term therapy with low-molecular-weight heparin (LMWH) is considered as standard treatment for cancer-associated VTE. However, several experimental studies and clinical trials suggest that LMWH may also be beneficial as an adjunct in the treatment of patients with malignant disease. This article provides an overview on the significance, pathogenesis and treatment of cancer-related clotting disorders as well as on the cellular and molecular mechanisms, by which haemostatic components such as TF, platelets and fibrin(ogen) drive tumour progression.

Topics: Hemostasis; Hemostatic Disorders; Humans; Neoplasm Metastasis; Neoplasms; Thromboplastin; Thrombosis; Venous Thromboembolism

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

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

Tissue factor, the primary initiator of the coagulation cascade, maintains vascular integrity in response to injury. It is now recognised that, in addition to the role as a procoagulant activator, tissue factor participates in many tumour-related processes that contribute to malignant disease progression. The present review details the recent evidence supporting a role for tissue factor in tumour haemostasis, angiogenesis, metastasis and malignant cell survival. Furthermore, future research directions are discussed that may enhance our understanding of the role and regulation of this protein, which could ultimately lead to the innovative design and development of new anticancer therapies.

Topics: Animals; Antineoplastic Agents; Cell Survival; Disease Progression; Gene Expression Regulation, Neoplastic; Hemostasis; Humans; Neoplasms; Neovascularization, Pathologic; Thromboplastin; Venous Thromboembolism

The relationship between increased clotting and malignancy is well recognized, though the bidirectional development of this association is often overlooked. In the challenging cancer biology, transforming genes often act in concert with numerous epigenetic factors, including hypoxia, inflammation, contact between blood and cancer cells, and emission of procoagulant vesicles from tumors, to determine a net imbalance of the hemostatic potential which is detectable by a variety of laboratory tests. Procoagulant factors, in particular, are intimately involved in all aspects of hemostatic, cell proliferation and cellular signalling systems. However, the biggest as yet unresolved question is why cancer patients develop thrombosis? Since the thrombus itself does not apparently contributes directly to the tumor biology, enhanced hemostasis activation in cancer patients may be interpreted according to the most recent biological evidences. Coagulation and cancer biology interact bidirectionally in a "vicious cycle", in which greater tumor burden supplies greater procoagulants (tissue factor, cancer procoagulant) and thrombin, which would in turn act as strong promoters of cancer growth and spread. In this perspective, thrombosis may be interpreted as a epiphenomenon of an intricate an effective biological feedback to maintain or promote cancer progression. In this review article, we briefly analyze the pathogenesis, laboratory, clinical and therapeutic features of cancer and thrombosis.

Topics: Blood Coagulation; Blood Flow Velocity; Blood Vessels; Humans; Neoplasms; Neovascularization, Pathologic; Thromboembolism; Thromboplastin; Thrombosis

Topics: Angiogenesis Inhibitors; Animals; Anticoagulants; Guideline Adherence; Heparin, Low-Molecular-Weight; Humans; Membrane Glycoproteins; Neoplasms; P-Selectin; Practice Guidelines as Topic; Pulmonary Embolism; Risk Assessment; Thromboplastin; Venous Thrombosis

A series of coordinated enzymatic reactions takes place in the body whenever blood clots. The major physiological initiator of these reactions is a membrane-bound glycoprotein known as tissue factor (TF), which is normally separated from the bloodstream by the vascular endothelium. Bleeding, caused by injury or tissue damage, activates a complex enzyme cascade as TF becomes exposed to the bloodstream. In disease states, leukocytes or the vascular endothelium may abnormally express TF to cause intravascular coagulation. The blood-coagulation cascade is also relevant to diseases such as hemophilia, in which patients are deficient in blood proteins necessary for clotting, and is linked to vascular diseases such as heart attack and stroke, in which clotting can lead to the occlusion of blood vessels. Coagulation is also activated in inflammation and cancer. In this article, we discuss characteristics of TF and review its role in inflammation and cancer.

Topics: Biomarkers; Blood Coagulation; Humans; Inflammation; Neoplasms; Thromboplastin

Clotting activation occurs frequently in cancer. Tissue factor (TF), the most potent initiator of coagulation, is expressed aberrantly in many types of malignancy and is involved not only in tumor-associated hypercoagulability but also in promoting tumor angiogenesis and metastasis via coagulation-dependent and coagulation-independent (signaling) mechanisms. Tissue factor pathway inhibitor (TFPI) is the natural inhibitor of TF coagulant and signaling activities. Studies have shown that TFPI exhibits antiangiogenic and antimetastatic effects in vitro and in vivo. In animal models of experimental metastasis, both circulating and tumor cell-associated TFPI are shown to significantly reduce tumor cell-induced coagulation activation and lung metastasis. Heparins and heparin derivatives, which induce the release of TFPI from the vascular endothelium, also exhibit antitumor effects, and TFPI may contribute significantly to those effects. Indeed, a non-anticoagulant low-molecular-weight heparin with intact TFPI-releasing capacity has been shown to have significant antimetastatic effect in a similar experimental mouse model. The evidence supporting the dual inhibitory functions on TF-driven coagulation and signaling strengthen the rationale for considering TFPI as a potential anticancer agent. This article primarily summarizes the evidence for antiangiogenic and antimetastatic effects of TFPI and describes its potential mechanisms of action. The possible application of TFPI and other inhibitors of TF as potential anticancer agents is described, and information regarding potential antitumor properties of TFPI-2 (which has structural similarities to TFPI) is also included.

Topics: Animals; Anticoagulants; Fibrinolytic Agents; Hemostasis; Heparin, Low-Molecular-Weight; Humans; Lipoproteins; Neoplasm Metastasis; Neoplasms; Neovascularization, Pathologic; Serine Proteinase Inhibitors; Thromboplastin

Angiogenesis, the growth of new blood vessels from preexisting ones, is a necessary component of embryogenesis, wound healing, and the proliferative phase of the female reproductive cycle. Angiogenesis also plays a critical role in important pathologic processes such as cancer and cardiovascular complications. In addition, clinical, laboratory, and pharmacologic evidence has shown a link between angiogenesis, coagulation, hemostasis, and thrombosis in the settings of these pathologies. Recent studies in our laboratory revealed that thrombin has a significant stimulatory effect on angiogenesis. This effect of thrombin is independent of fibrin formation and can be attributed mainly to the activation of protease-activated receptor-1 (PAR-1). PAR-1 is widely expressed in vascular cells and is involved in cardiovascular complications such as atherosclerosis, restenosis, and neointimal formation. It is also expressed in many cancer cells contributing to induction of tumor growth and metastasis. In this review, we will summarize our present-day understanding of the role of thrombin and PAR-1 in angiogenesis and the potential therapeutic utility of targeting PAR-1 in angiogenesis-related disease, such as atherosclerosis, restenosis, and cancer.

Topics: Animals; Apoptosis; Blood Coagulation; Blood Vessels; Cardiovascular Diseases; Endothelium, Vascular; Humans; Neoplasm Metastasis; Neoplasms; Neovascularization, Pathologic; Neovascularization, Physiologic; Receptor, PAR-1; Thrombin; Thromboplastin

This review summarizes data demonstrating the role of TF in tumor development, metastasis and angiogenesis. TF is a transmembrane protein that is expressed constitutively in some kinds of extravascular cells and transiently in intravascular cells after stimulation with cytokines and growth factors. Originally TF was considered to have a function in the initiation of coagulation. In the last years it became evident that TF plays a role in physiological and pathological processes outside the hemostasis. Up-regulation of TF expression appears to be characteristic of tumor tissue. In a variety of human tumors it was shown by immunohistochemistry, that TF can be expressed in malignant cells as well as in tumor-infiltrating macrophages or endothelial cells. Such abnormal TF expression contributes to the angiogenic process by a shift in the balance between endogenous proangiogenic and antiangiogenic factors. Observations of a significant correlation between elevated TF expression with increased microvessel density and VEGF expression underline the TF involvement in tumor angiogenesis. Furthermore, TF expression influences also metastasis. The effect of TF on metastasis may result from its angiogenic effect, but also from the production of growth factors or adhesion proteins.

Topics: Animals; Biomarkers, Tumor; Gene Expression Regulation, Neoplastic; Humans; Neoplasms; Predictive Value of Tests; Prognosis; Thromboplastin

The complex of the cell surface receptor tissue factor (TF) and its ligand coagulation factor VIIa (FVIIa) is the primary initiator of the coagulation cascade. It is now clear the TF-initiated coagulation pathway also plays major nonhemostatic roles in inflammation, tumor growth, and angiogenesis. Direct or indirect cell signaling by TF-FVIIa or downstream coagulation proteases is an essential part of these nonhemostatic functions. The TF-FVIIa complex activates protease-activated receptor 2 and thus regulates gene transcription and protein translation, cell proliferation and survival, or cell motility and integrin activation. In this review, we relate our current understanding of direct TF signaling pathways to the emerging roles of TF in (patho)physiology.

Topics: Animals; Cell Movement; Cell Proliferation; Factor VIIa; Gene Expression Regulation; Humans; Inflammation; Integrins; Ligands; Neoplasms; Neovascularization, Pathologic; Neovascularization, Physiologic; Protein Biosynthesis; Receptor, PAR-2; Signal Transduction; Thromboplastin

Tissue factor (TF), the primary cellular initiator of blood coagulation, is also involved in cancer-related processes such as hypercoagulability (Trousseau syndrome), tumor growth, angiogenesis, and metastasis. Indeed, elevated TF expression by cancer cells and their associated endothelial cells has been reported frequently. Oncogenic events in cancer cells (e.g., expression of mutant K- ras, EGFR, PTEN or p53) lead to an increase in TF levels and activity, and thereby promote tumor aggressiveness, angiogenesis, and hypercoagulability. Like TF, thrombin receptor (protease-activated receptor-1) is also upregulated in cancer cells expressing oncogenic K -ras. Pharmacological antagonists of some of these transforming genes (e.g., epidermal growth factor receptor inhibitors) could diminish TF expression, both locally and systemically, and hence these targeted agents could be viewed as potential indirect and cancer-specific anticoagulants, in addition to their direct antitumor effects. We postulate that levels of circulating TF may be useful in monitoring the biological activity of these agents. Although TF is essential for vascular development, its expression by tumor-associated endothelium appears to play a subtle and seemingly dispensable role. Thus, TF is a pivotal element of the tumor-vascular interface, is involved in many cancer-related processes, and may well constitute a promising new target for anticancer combination therapies in some disease settings.

Topics: Animals; Blood Coagulation; Disease Progression; Enzyme Inhibitors; Gene Expression Regulation, Neoplastic; Humans; Neoplasm Metastasis; Neoplasm Proteins; Neoplasms; Neovascularization, Pathologic; Signal Transduction; Thrombin; Thromboplastin

Progression of human malignancies is accompanied by vascular events, such as formation and remodeling of blood vessels and systemic coagulopathy. Though long appreciated as comorbidity of cancer (Trousseau syndrome), vascular involvement is increasingly recognized as a central pathogenetic mechanism of tumor growth, invasion and metastasis. The major outstanding question in relation to this role has been, whether vascular perturbations are simply a reaction to the conditions of the tumor microenvironment, or are linked to the known genetic lesions causal for the onset and progression of malignancy. In this regard, we have previously hypothesized, and recently demonstrated experimentally that deregulation of certain hemostatic mechanisms, namely upregulation of tissue factor (TF) and possibly other changes (e.g. expression of thrombin receptor - PAR-1) are controlled by cancer-associated oncogenic events, such as activation of K-ras, epidermal growth factor receptor (EGFR), or inactivation of the p53 tumor suppressor gene in various human cancer cells. It appears that these respective transforming alterations exert their impact on both, cell-associated and soluble/circulating (microvesicle- associated) TF, i.e. may cause a systemic hypercoagulable state. Other genes, which more recently emerged as regulators of cancer coagulopathy include: PML-RARalpha, PTEN, and MET. While the spectrum of procoagulant targets of these genes may vary somewhat it includes: TF, PAI-1, COX-2 and possibly other hemostatic proteins. It is noteworthy that these prothrombotic changes may impact the malignant process directly (e.g. stimulate angiogenesis, tumor growth or metastasis) as a consequence of both coagulation-dependent and -independent effects. The latter are mostly related to cellular signaling events and changes in gene expression which are now known to be induced by the TF/FVIIa/Xa complex, thrombin and PARs, expressed on the surface of cancer cells, as well as tumor-associated endothelium. Interestingly, certain anticoagulants possess antimetastatic and anticancer properties (e.g. LMWH), an observation that further suggests that hypercoagulability may act as an effector mechanism of genetically driven tumor progression. Conversely, we suggest that oncogene-directed (targeted) anticancer agents could, at least in some cases, ameliorate not only cellular transformation itself, but also some of the chronic components of the cancer-related coagulopathy, something that ma

Topics: Animals; Blood Coagulation Disorders; Disease Progression; Genes, Tumor Suppressor; Hemostasis; Humans; Neoplasms; Neovascularization, Pathologic; Paraneoplastic Syndromes; Thromboplastin

Advanced cancer is associated with a hypercoagulable state that is triggered by tissue factor (TF). TF-initiated thrombin generation is crucial for metastasis through fibrin and platelet deposition, as well as thrombin-dependent protease-activated receptor (PAR) 1 signaling. Surprisingly, PAR2, which is not cleaved by thrombin, appears to cosignal with PAR1 to elicit thrombin effects in metastatic tumor cells. In contrast to TF-driven thrombin pathways in metastasis, direct TF signaling plays a role in angiogenesis-dependent tumor growth. In TF cytoplasmic-domain-deleted mice, PAR2-dependent angiogenesis and tumor growth is enhanced, demonstrating a role for host cell TF signaling. In tumor cells, TF-factor VIIa (FVIIa) activates PAR2 and thereby regulates proangiogenic growth factor expression as well as integrins involving crosstalk with the TF cytoplasmic domain. In addition to thrombin-PAR signaling in metastasis and TF-FVIIa-PAR2 signaling in tumor growth, it is likely that additional protease pathways will prove to be crucial activators of PARs in cancer. Transmembrane serine proteases as well as matrix metalloproteinase are prime candidates for accessory pathways to regulate metastasis, tumor expansion, and angiogenesis dependent on specific features of the local tumor microenvironment.

Topics: Animals; Humans; Neoplasm Metastasis; Neoplasms; Neovascularization, Pathologic; Receptors, Proteinase-Activated; Thrombin; Thromboplastin

Substantial epidemiologic, laboratory, pathologic and clinical evidence supports the historic association between activation of blood coagulation and progression of cancer. The increased risk for venous thromboembolism(VTE) in cancer has been considered an epiphenomenon. However, recent studies from several laboratories have linked more closely malignanttransformation (oncogenesis), tumor angiogenesis and metastasis to the generation of clotting intermediates(e.g. tissue factor [TF], factor Xa and thrombin),clotting or platelet function inhibitors (e.g. COX-2) or fibrinolysis inhibitors (e.g. plasminogen activator inhibitor, type 1 [PAI-1]). Furthermore, TF, Xa and thrombin may induce important tumor cell signaling cascades in a clotting-dependent and/or clotting independent manner (e.g. thru engagement of protease-activated receptors [PARs]). Targeting blood clotting reactions in cancer may provide a unique approach to cancer treatment.

Topics: Blood Coagulation Factors; Humans; Neoplasms; Thromboplastin; Thrombosis

Activation of coagulation precedes or coincides with angiogenesis in wound healing and postischemic tissue regeneration. Advanced cancer is associated with a hypercoagulable state, and tissue factor expression by cancer cells has received widespread attention because of its significant contribution to the pathogenesis of cancer progression and metastasis. Our recent work demonstrates that tissue factor-mediated cellular signaling is relevant to cancer angiogenesis. Here we review the molecular mechanisms of tissue factor pathways in angiogenesis and tumorigenesis with emphasis on the intriguing role for tissue factor cytoplasmic domain signaling.

Topics: Blood Coagulation; Humans; Neoplasms; Neovascularization, Pathologic; Signal Transduction; Thromboplastin

Topics: Anticoagulants; Blood Coagulation; Chemotaxis; Factor VIIa; Humans; Integrins; Lipoproteins; Models, Biological; Neoplasm Metastasis; Neoplasms; Neovascularization, Pathologic; Signal Transduction; Thromboplastin; Thrombosis; Vascular Endothelial Growth Factor A

Up-regulation of tissue factor (TF) is often observed in cancer. TF is a cell-associated receptor for coagulation factor VII/VIIa, an interaction known to activate the coagulation cascade. At the same time, TF is also known as a mediator of intracellular signaling events that can alter gene expression patterns and cell behavior. Both aspects of TF activity are of possible relevance to tumor growth, metastasis, and angiogenesis, including up-regulation of vascular endothelial growth factor (VEGF). TF up-regulation is often observed on the surfaces of tumor-associated endothelial cells, inflammatory cells, and particularly on cancer cells themselves. In the last case, high TF levels may be associated with poor prognosis and parallel clinical (and genetic) tumor progression. We have proposed elsewhere that TF may be a target of oncogenic events in cancer. Here we discuss our observations suggesting that oncogene-targeting agents may down-regulate TF expression. Such is the effect of treatment with the neutralizing monoclonal antibody (C225) raised against the epidermal growth factor receptor (EGFR) in EGFR-dependent squamous cell carcinoma cells (A431). This two- to threefold TF down-regulation by C225 treatment is paralleled by a decrease in expression of VEGF. It is conceivable that TF participates in signals that regulate VEGF and angiogenesis triggered by activated oncogenic pathways. Therefore, direct targeting of TF in cancer should be considered in combination with other treatment modalities such as oncogene-directed therapies, antiangiogenic agents (e.g., VEGF antagonists), and anti-cancer chemotherapy.

Topics: Gene Expression Regulation, Neoplastic; Humans; Neoplasms; Neovascularization, Pathologic; Oncogenes; Thromboplastin; Vascular Endothelial Growth Factor A

The hypercoagulability exhibited by most cancer patients leads to serious complications such as venous thromboembolism and contributes to the pathogenesis of tumor growth and metastasis by promoting angiogenesis. The key player in this vicious cycle is tissue factor (TF), the initiator of blood coagulation. Although TF normally safeguards vascular integrity by inducing hemostasis upon injury, abnormal expression of TF in different tumors and related vascular endothelial cells contributes to unnecessary clot formation in cancer patients. Clotting-dependent induction of tumor angiogenesis is primarily mediated by TF-induced generation of thrombin and subsequent deposition of cross-linked fibrin. A cross-linked fibrin network provides a provisional proangiogenic matrix that facilitates blood vessel infiltration. Clotting-independent mechanisms of TF-induced tumor angiogenesis have also been described, mediated primarily by the cytoplasmic tail of the TF receptor. TF activation could contribute to the venous thromboembolism that has been reported as a complication of the use of novel antiangiogenic agents in combination with chemotherapy. Anticoagulants, such as low-molecular-weight heparin, may act to prevent these complications both by interfering with TF-mediated activation of clotting and by directly down-regulating angiogenesis. Thus, TF may prove to be a novel target for cancer therapy.

Topics: Animals; Fibrin; Humans; Neoplasms; Neovascularization, Pathologic; Thrombophilia; Thromboplastin

Thrombosis and disseminated intravascular coagulation (DIC) are common complications in cancer. Patients with malignancy have a prothrombotic state due to the ability of almost all type of cancer cells to activate the coagulation system. However, none of the haemostatic markers of coagulation has any predictive value for the occurrence of the thrombotic events in one individual patient. The pathogenesis of the prothrombotic state in cancer is complex and, probably, multifactorial. Prothrombotic factors in malignancy include the tumour production of procoagulants (i.e., tissue factor (TF) and cancer procoagulant (CP)) and inflammatory cytokines, and the interaction between tumour cells and blood (i.e., monocytes/macrophages, platelets) and endothelial cells. Other mechanisms of thrombus promotion include some general responses of the host to the tumour (i.e., acute phase, inflammation, angiogenesis), decreased levels of inhibitors of coagulation, and impaired fibrinolysis. In addition, the prothrombotic tendency of cancer patients is enhanced by anticancer therapy, such as surgery, chemotherapy, hormone therapy and radiotherapy, by indwelling central venous catheter, and by haemodinamic compromise (i.e., stasis). However, not all of the mechanisms allowing the prothrombotic state of cancer are entirely understood. Therefore, it is presently difficult to rank the relative weight of these multiple interactions on the basis of the well-recognised clinical evidences of enhanced thrombotic episodes in patients with cancer. In this review we attempt to describe the current proposed mechanisms for the pathogenesis of the prothrombotic state in cancer patient. A better understanding of these mechanisms could help clinicians in the developments of more targeted treatment to prevent thromboembolic complications in cancer patient.

Topics: Biomarkers; Blood Cells; Blood Coagulation; Cysteine Endopeptidases; Cytokines; Disseminated Intravascular Coagulation; Fibrinolysis; Humans; Neoplasm Proteins; Neoplasms; Neovascularization, Pathologic; Thromboplastin; Thrombosis

Topics: Angiogenesis Inhibitors; Animals; Hemostasis; Heparin, Low-Molecular-Weight; Humans; Mice; Neoplasms; Neovascularization, Pathologic; Thromboplastin

The transmembrane glycoprotein tissue factor (TF) is the initiator of the coagulation cascade in vivo. When TF is exposed to blood, it forms a high-affinity complex with the coagulation factors factor VII/activated factor VIIa (FVII/VIIa), activating factor IX and factor X, and ultimately leading to the formation of an insoluble fibrin clot. TF plays an essential role in hemostasis by restraining hemorrhage after vessel wall injury. An overview of biological and physiological aspects of TF, covering aspects consequential for thrombosis and hemostasis such as TF cell biology and biochemistry, blood-borne (circulating) TF, TF associated with microparticles, TF encryption-decryption, and regulation of TF activity and expression is presented. However, the emerging role of TF in the pathogenesis of diseases such as sepsis, atherosclerosis, certain cancers and diseases characterized by pathological fibrin deposition such as disseminated intravascular coagulation and thrombosis, has directed attention to the development of novel inhibitors of tissue factor for use as antithrombotic drugs. The main advantage of inhibitors of the TF*FVIIa pathway is that such inhibitors have the potential of inhibiting the coagulation cascade at its earliest stage. Thus, such therapeutics exert minimal disturbance of systemic hemostasis since they act locally at the site of vascular injury.

Topics: Animals; Arteriosclerosis; Blood Coagulation; Blood Coagulation Disorders; Blood Coagulation Factors; Blood Vessels; Disseminated Intravascular Coagulation; Fibrin; Gene Expression Regulation; Humans; Neoplasms; Sepsis; Thromboplastin; Thrombosis

Venous thromboembolism (VTE), manifested as either deep venous thrombosis (DVT) or pulmonary embolism (PE), is an extremely common medical problem, occurring either in isolation or as a complication of other diseases or procedures. Yet, despite its frequency, much remains to be learned regarding the pathogenic mechanisms that initiate VTE, about tailoring its treatment to the individual with her/his specific set of risk factors for recurrence, and about its medical management when associated with specific disease entities, such as cancer. These three topics are addressed in this chapter. In Section I, Drs. López and Conde discuss the mechanisms by which venous thrombi may be initiated on the vessel wall in the absence of anatomically overt vessel wall injury. The authors propose a model whereby tissue factor (TF)-bearing microvesicles that arise from cells of monocyte/macrophage lineage can fuse with activated endothelial cells in regions of vessel activation or inflammation and initiate blood coagulation. Key components of this model include docking of the microvesicles to the stimulated endothelium through P-selectin glycoprotein ligand-1 on their surfaces binding to either P-selectin or E-selectin on the endothelium, and the role of hypoxia during blood stasis in initiating local endothelial activation. Elevations in the levels of TF-bearing microvesicles associated with inflammatory conditions would help to explain the increased risk of thrombosis associated with infections and inflammatory states such as inflammatory bowel disease. In Section II, Dr. Clive Kearon discusses the risk factors for recurrent thrombosis and strategies for determining length of therapy and tailoring specific therapies through risk stratification. Those patients who experience VTE in association with a major reversible risk factor such as surgery are much less likely to experience a recurrence when anticoagulation is discontinued than are patients with a persistent risk factor, such as thrombophilia or cancer unresponsive to therapy. Those with a minor reversible risk factor, such as prolonged air travel, have an intermediate risk of recurrence after discontinuance of anticoagulant therapy. The author provides an algorithm for using risk assessment as a means of determining the length and type of therapy to be used to minimize the rate of recurrence while simultaneously diminishing the risk of bleeding associated with anticoagulation. In Section III, Dr. Agnes Lee updates th

Topics: Heparin, Low-Molecular-Weight; Humans; Hypoxia; Inflammation; Neoplasms; Prognosis; Pulmonary Embolism; Risk Factors; Thromboplastin; Thrombosis; Venous Thrombosis

Topics: Biomarkers; Blood Coagulation Tests; Disseminated Intravascular Coagulation; Enzyme-Linked Immunosorbent Assay; Humans; Leukemia; Lipoproteins; Neoplasms; Specimen Handling; Thromboplastin

Tissue factor (TF), a 47-kDa transmembrane glycoprotein, is a principal regulator of oncogenic neoangiogenesis and controls therefore the cancerous process. Although originally identified as a component of the coagulation cascade, it has become clear that TF functions as a cytokine-like receptor and this notion was confirmed by the discovery of coagulation-independent actions of TF (which include regulation of tumour growth, embryonic and oncogenic blood vessel formation as well as regulation of inflammation and sepsis). In accordance, TF-mediated signal transduction events are readily detected and the elucidation of the underlying molecular mechanisms has recently seen spectacular progress and it is now understood that the role of TF in angiogenesis is both coagulation-dependent and independent. The recent evidence for this emerging insight will be the subject of this review.

Topics: Animals; Blood Coagulation; Humans; Mice; Neoplasms; Neovascularization, Pathologic; Signal Transduction; Thromboplastin

Since the observations of Trousseau, not only has the association of cancer and thrombosis been widely recognized but its pathogenesis is now better understood. Attention to the tumor cell as an important source of procoagulants has also contributed to our knowledge of this problem. Tumor cells express tissue factor (TF) and a cancer procoagulant (CP). TF is dormant in the living cell. However, it is activated during apoptosis of the cell, initiating the coagulation cascade and leading to thrombin generation. Because increased apoptosis occurs during treatment with chemotherapeutic agents, hormones, radiation, and hematopoietic growth factors, as well as when there is rapid tumor proliferation, the thrombosis risk is heightened accordingly. These developments have obvious basic and clinical implications.

Topics: Apoptosis; Blood Coagulation Factors; Humans; Neoplasms; Thromboplastin; Thrombosis

In addition to its primary role in hemostasis and blood coagulation, thrombin is a potent mitogen capable of inducing cellular functions. Therefore, it should come as no surprise that thrombin has proved to be of importance in the behavior of cancer. In this review, we focus on the ability of tissue factor (TF) and thrombin to influence tumor angiogenesis. Both exert their influence on angiogenesis through clotting-dependent and clotting-independent mechanisms: (1). directly affecting signaling pathways that mediate cell functions, and (2). mediating clot formation, thereby providing a growth media for tumor cells. Therefore, anticoagulant drugs may prove efficacious in cancer treatment due to their ability to reduce the characteristic hypercoagulability of cancer and alter the fundamental biology of cancer.

Topics: Fibrin; Humans; Neoplasms; Neovascularization, Pathologic; Thrombin; Thromboplastin; Thrombosis

Idiopathic thrombosis often precedes the diagnosis of occult cancer by several years. Whether hypercoagulability predisposes for malignancy or the converse holds true is an unresolved paradigm that stems from the known vicious cycle of clot formation and tumor growth. Central to this paradigm is the interplay between tissue factor (TF), the initiator of coagulation, and angiogenesis, the life support of tumors. Both clotting-dependent and -independent mechanisms of TF-induced angiogenesis have been elucidated that may signal through distinct pathways. This review focuses on the latest studies of TF and angiogenesis and highlights recent applications that have led to the development of promising new TF-targeted cancer therapeutics. Finally a cautionary note is given about unexpected complications arising from antiangiogenic therapy that may potentially involve TF.

Topics: Animals; Blood Coagulation; Humans; Neoplasms; Neovascularization, Pathologic; Signal Transduction; Thromboplastin

Exposure of blood to tissue factor (TF) sets off the coagulation cascade. TF is a transmembrane protein that serves as an essential cofactor for activated coagulation factor VII (FVIIa). TF may be exposed locally by vascular injury (such as balloon angioplasty) or by spontaneous rupture of an atherosclerotic plaque. Expression of TF may also be induced on monocytes and endothelial cells in conditions like sepsis and cancer, causing a more generalised activation of clotting. TF may thus play a central role in thrombosis in a number of settings, and attention has turned to blocking TF as a means to prevent thrombosis. Inhibiting the inducible expression of TF by monocytes can be achieved by 'deactivating' cytokines, such as interleukin (IL)-4, -10 and -13, or by certain prostanoids; by drugs that modify signal transduction, such as pentoxifylline, retinoic acid or vitamin D(3), or by antisense oligonucleotides. Such approaches are for the most part at a preclinical stage. The function of TF can be blocked by antibodies that prevent the binding of FVIIa to TF; by active site-inhibited FVIIa, which competes with native FVIIa for binding; by antibodies or small molecules that block the function of the TF/FVIIa complex; and by molecules, such as TF pathway inhibitor or nematode anticoagulant peptide C2, which inhibit the active site of FVIIa in the TF/FVIIa complex after first binding to activated factor X. The latter two agents have entered Phase II clinical trials. Perhaps most intriguing is the use of anti-TF agents locally, which holds the promise of stopping thrombosis at a specific site of injury without the bleeding risk associated with systemic anticoagulation.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Antibodies, Monoclonal; Arteriosclerosis; Blood Coagulation; Clinical Trials as Topic; Cytokines; Drug Design; Endothelium, Vascular; Enzyme Activation; Factor VIIa; Fibrinolytic Agents; Glycoproteins; Helminth Proteins; Hemorrhage; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Lipoproteins; Mice; Monocytes; Multiprotein Complexes; Neoplasms; Oligonucleotides, Antisense; Prostaglandins; Signal Transduction; Swine; Swine, Miniature; Thrombophilia; Thromboplastin; Thrombosis

Tissue Factor is the principal cellular initiator of normal blood coagulation. It is frequently encrypted in the plasma membrane of cells in contact with blood, but under certain pathological conditions endothelial cells, monocytes or macrophages may express tissue factor; and hence trigger coagulation activation. Aberrant expression of tissue factor by these cells is thought to be responsible for the thrombophilia found in septic shock, atherosclerosis and cancer. Tissue factor is produced by tumor-associated macrophages where it is believed to play an important role in tumor growth and dissemination. It may also be involved in other cellular processes such as intracellular signalling, angiogenesis and embryonic blood-vessel development. Tissue factor can be found both as free (soluble tissue factor) and membrane bound forms. Several studies have shown that measurements of any of these forms may provide clinically significant information, particularly in patients with malignant and inflammatory diseases, and are cost-effective.

Topics: Blood Coagulation; Glomerulonephritis; Hematologic Tests; Humans; Neoplasms; Neovascularization, Pathologic; Thromboplastin

Tumours are capable of activating blood coagulation through the expression of procoagulant molecules such as tissue factor, cancer procoagulant and hepsin. Initiation of the clotting cascade results in the generation of the activated serine proteases factor VIIa, factor Xa and thrombin. These proteases act via protease-activated receptors and tissue factor to alter gene expression, thereby modulating tumour cell growth, invasion, metastasis and angiogenesis.

Topics: Blood Coagulation; Endopeptidases; Endothelial Growth Factors; Gene Expression Regulation, Neoplastic; Humans; Intercellular Signaling Peptides and Proteins; Lipoproteins; Lymphokines; Neoplasms; Thromboplastin; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors

Tissue factor (TF, coagulation factor III, CD142) is not only the main physiological initiator of normal blood coagulation, but is also important in the natural history of solid malignancies in that it potentiates metastasis and angiogenesis and mediates outside-in signalling. TF is expressed constitutively by many tissues which are not in contact with blood and by other cells upon injury or activation; the latter include endothelial cells, tissue macrophages, and peripheral blood monocytes. It can exist encrypted and unavailable functionally in the plasma membrane and the appearance of functional TF may be due to synthesis and/or de-encryption. Inflammatory cells often express TF and act to induce its production or de-encryption by other cells locally and, apparently, at remote sites. Inappropriate expression of TF by endothelial cells, macrophages or monocytes is thought to be an important trigger of coagulation in various pathological conditions. Several studies have shown that measurements of monocyte TF (mTF) may provide clinically significant information, particularly in patients with malignant and inflammatory diseases.

Topics: Biomarkers, Tumor; Blood Coagulation; Gene Expression Regulation; Humans; Monocytes; Neoplasms; Thromboplastin

Cancer patients are prone to venous thromboembolism (VTE), and this hypercoagulability favors tumor growth and metastasis. After a brief review of the clinical aspects of VTE and cancer, we discuss the pathogenesis of hypercoagulability with an emphasis on the role of tissue factor (TF). The discovery that, in addition to tumor cells, TF is expressed by tumor-associated macrophages and tumor-associated endothelial cells led to studies of the role of TF in the regulation of tumor angiogenesis. In human lung cancer, melanoma, and breast cancer, TF and vascular endothelial growth factor (VEGF) co-localize in tumor cells; a close correlation exists between TF and VEGF synthesis (P = .001) in tumor cell lines and with angiogenesis in vivo in a severe, combined immunodeficient mouse model. Transfection of a TF/VEGF low-producing human tumor cell line with full length TF complementary DNA (cDNA) results in conversion to a high producer of TF and VEGF; transfection of a deletion-mutant TF cDNA lacking cytoplasmic serine residues restores full TF procoagulant activity but not VEGF synthesis to the cells. These results suggest that the cytoplasmic tail of TF is necessary for tumor cell VEGF synthesis. Targeting of TF in tumors and tumor-associated blood vessels is discussed as a strategy for drug delivery and rational anti-cancer and anti-angiogenesis drug design.

Topics: Cell Division; Fibrin; Hemostatics; Humans; Neoplasm Metastasis; Neoplasms; Neovascularization, Pathologic; Thromboplastin

Tumor cells produce tissue factor, cancer procoagulant, plasminogen activators and other factors that interact with the coagulation system, the fibrinolytic system and vascular or blood cells such that they can upset the normal homeostasis and balance between activation and inhibition of the coagulation and fibrinolytic systems. These activities play a role in tumor cell growth and metastasis, vascular wall function, and hemostasis. Proteases and their inhibitors are intimately involved in all aspects of the hemostatic, cell proliferation and cellular signalling systems. This review provides a brief examination of recent observations in this complex interaction of cellular and hemostatic factors.

Topics: Blood Coagulation; Blood Coagulation Factors; Humans; Neoplasms; Thrombophilia; Thromboplastin

Human tissue factor pathway inhibitor (TFPI) is a modular protein comprised of three Kunitz type domains flanked by peptide segments that are less structured. The sequential order of the elements are: an N-terminal acidic region followed by the first Kunitz domain (K1), a linker region, a second Kunitz domain (K2), a second linker region, the third Kunitz domain (K3), and the C-terminal basic region. The K1 domain inhibits factor VIIa complexed to tissue factor (TF) while the K2 domain inhibits factor Xa. No direct protease inhibiting functions have been demonstrated for the K3 domain. Importantly, the Xa-TFPI complex is a much more potent inhibitor of the VIIa-TF than TFPI by itself. Furthermore, the C-terminal basic region of TFPI is required for rapid physiologic inhibition of coagulation and is needed for the inhibition of smooth muscle cell proliferation. Although a number of additional targets for attachment have been reported, the C-terminal basic region appears to play an important role in binding of TFPI to cell surfaces. A primary site of TFPI synthesis is endothelium and the endothelium-bound TFPI contributes to the antithrombotic potential of the vascular endothelium. Further, increased levels of plasma TFPI under septic conditions may represent endothelial dysfunction. We have proposed that the extravascular cells that synthesize TF also synthesize TFPI providing dual components necessary for the regulation of clotting in their microenvironment. Like the TF synthesis in these cells is augmented by serum, so is the case with the TFPI gene expression. TFPI gene knock out mice reveal embryonic lethality suggesting a possible role of this protein in early development. Since TF-induced coagulation is thought to play a significant role in many disease states, including disseminated intravascular clotting, sepsis, acute lung injury and cancer, recombinant TFPI may be a beneficial therapeutic agent in these disease states to attenuate pathologic clotting. The purpose of this review is to outline recent developments in the field related to the structural specificity and biology of TFPI.

Topics: Acute Disease; Amino Acid Sequence; Amino Acids; Antiphospholipid Syndrome; Blood Coagulation; Cardiovascular Diseases; Endothelium, Vascular; Humans; Lipoproteins; Lung Diseases; Models, Biological; Models, Molecular; Molecular Sequence Data; Neoplasm Metastasis; Neoplasms; Protein Conformation; Protein Structure, Tertiary; Sepsis; Sequence Alignment; Sequence Homology, Amino Acid; Structure-Activity Relationship; Thrombophilia; Thromboplastin

Because of its unique position at the convergence point of the intrinsic (contact) and extrinsic (tissue factor/factor VIIa) pathways in the coagulation system, coagulation factor Xa (FXa) has been a theoretically interesting therapeutic target for antithrombotic drugs for many years. More recently, the discovery of naturally occurring FXa inhibitors, such as tick anticoagulant peptide and antistasin, has helped substantiate FXa as a desirable target by demonstrating the efficacy and potential safety advantages of FXa inhibition over conventional antithrombotic therapy. These discoveries led to the design and development of many small-molecule inhibitors of FXa, which have provided potent and selective tools for evaluating the potential role of FXa in various diseases. In addition, these advances have been instrumental in defining the biology of FXa and have aided in the discovery of specific receptors and intracellular signaling pathways for FXa that may be important in the progression of, or the response to, various diseases.

Topics: Animals; Cell Adhesion; Clinical Trials as Topic; Coronary Restenosis; Cysteine Endopeptidases; Cytokines; Factor Xa; Factor Xa Inhibitors; Graft Occlusion, Vascular; Humans; Hyperplasia; Inflammation; MAP Kinase Signaling System; Neoplasm Proteins; Neoplasms; Platelet-Derived Growth Factor; Receptor, PAR-2; Receptors, Platelet-Derived Growth Factor; Receptors, Thrombin; Sepsis; Thromboplastin; Up-Regulation

Tissue factor, a 47 kDa membrane glycoprotein, lies at the basis of the extrinsic pathway of the coagulation cascade. Interaction of TF with factor VIIa results in the formation of fibrin from fibrinogen, thereby inducing the formation of a blood clot. In addition to this well-established role in blood coagulation, TF is associated with various other physiological processes such as sepsis, inflammation, angiogenesis, metastasis and atherosclerosis. The molecular basis of the latter events is slowly emerging. It has become clear that TF-FVIIa interaction elicits a variety of intracellular signalling events that may be implicated in these actions. These events include the sequential activation of Src-like kinases, MAP kinases, small GTPases and calcium signalling. How this progress in the understanding of TF associated signal transduction may generate answers as to the mechanism through which TF exerts it pleiotropic effects will be focus of this review.

Topics: Animals; Arteriosclerosis; Blood Coagulation; Calcium Signaling; Cytokines; Disseminated Intravascular Coagulation; Factor VIIa; Fibroblasts; Gene Expression Regulation; GTP Phosphohydrolases; Humans; Inflammation; Lipoproteins; Lipoproteins, LDL; MAP Kinase Signaling System; Mice; Mice, Knockout; Muscle, Smooth, Vascular; Neoplasm Metastasis; Neoplasms; Neovascularization, Physiologic; Papio; Phagocytes; Sepsis; Signal Transduction; src-Family Kinases; Thromboplastin

The coagulation system, which is activated in most cancer patients, has an important role in tumour biology. It may make a substantial contribution to tumour angiogenesis, which represents an imbalance in the normal mechanisms that allow organised healing after injury. The recently recognised, but steadily growing, knowledge of the relationship between the coagulation and angiogenesis pathways has research and clinical implications. Manipulation of these systems may minimise both the neoangiogenesis essential for tumour growth and associated thromboembolic complications. However, since surgery is the primary treatment for most cancers, the angiogenesis of wound healing and haemostatic competence must be maintained. In this article, we summarise the complex interactions between the coagulation system and the angiogenic process that occur in cancer growth. We focus upon the contributions of the vascular endothelium, platelets, and coagulation factors to the angiogenic process and explore the coagulation system as a therapeutic target.

Topics: Blood Coagulation; Blood Platelets; Endothelium, Vascular; Humans; Neoplasms; Neovascularization, Pathologic; Plasminogen; Thromboplastin

Topics: Animals; Infarction; Mice; Mice, Nude; Neoplasms; Neovascularization, Pathologic; Thromboplastin

The paper reviews the current studies on mechanism of thrombo-embolic complications in patients with malignancy. The neoplastic cells can express procoagulants like tissue factor (TF), cancer procoagulant (CP) and others, which induce thrombin formation in blood plasma and cause thrombo-embolic events, disseminated intravascular coagulation and other complications. Both procoagulants are acting via extrinsic pathway--TF makes complexes with factor VII and calcium ions, while CP acts directly on factor X transforming it into active form (Xa). Gynecological tumor-related complications occur in 20-30% patients with ovarian or uterine cancer.

Topics: Antineoplastic Agents; Female; Humans; Neoplasms; Ovarian Neoplasms; Thromboembolism; Thromboplastin; Uterine Neoplasms

There is considerable evidence that the hemostatic system is involved in the growth and spread of malignant disease. There is an increased incidence of thromboembolic disease in patients with cancers and hemostatic abnormalities are extremely common in such patients. Antihemostatic agents have been successfully used to treat a variety of experimental tumors, and several clinical trials in humans have been initiated. Although metastasis is undoubtedly multifactorial, intravascular coagulation activation and peritumor fibrin deposition seem to be important. The mechanisms by which hemostatic activation facilitates the malignant process remain to be completely elucidated. Of central importance may be the presence on malignant cells of tissue factor and urokinase receptor. Recent studies have suggested that these proteins, and others, may be involved at several stages of metastasis, including the key event of neovascularization. Tissue factor, the principal initiator of coagulation, may have additional roles, outside of fibrin formation, that are central to the biology of some solid tumors.

Topics: Animals; Anticoagulants; Antineoplastic Agents; Biomarkers; Blood Coagulation Tests; Cell Adhesion; Cysteine Endopeptidases; Disseminated Intravascular Coagulation; Factor Xa; Fibrin; Fibrinolysis; Hemostasis; Heparin; Humans; Monocytes; Neoplasm Metastasis; Neoplasm Proteins; Neoplasms; Neoplasms, Experimental; Neoplastic Cells, Circulating; Neovascularization, Pathologic; Platelet Activation; Platelet Aggregation Inhibitors; Receptors, Thrombin; Thrombophilia; Thrombophlebitis; Thromboplastin; Vitamin K

Over the last years numerous studies have focussed on the in vivo expression of tissue factor (TF) in health and disease. The selective perivascular distribution of TF and the lethal effects of TF knockouts have added strong support to the widely accepted view that TF plays a pivotal role in the initiation of blood coagulation during physiological hemostasis. Inappropriate in vivo expression of TF, particularly by cells that do not express this protein under normal conditions (mainly monocyte-macrophages and endothelial cells), has been documented and is likely responsible for fibrin deposition in a variety of pathological conditions, among which sepsis-associated disseminated intravascular coagulation (DIC) and thromboembolic disease. In malignancy, in vivo expression of TF by tumor cells and/or by host cells has been implicated not only in intratumoral and systemic activation of blood coagulation but also in tumor growth and dissemination.

Topics: Arteriosclerosis; Disseminated Intravascular Coagulation; Humans; Neoplasms; Reference Values; Thrombophlebitis; Thromboplastin; Thrombosis

Topics: Animals; Blood Coagulation; Blood Coagulation Factors; Cell Membrane; Cytokines; Disseminated Intravascular Coagulation; Endothelium, Vascular; Endotoxins; Gene Expression Regulation; Growth Substances; Humans; Mice; Neoplasms; Organ Specificity; Protein Processing, Post-Translational; Sepsis; Thromboplastin

Tumor cells frequently express tissue factor, a transmembrane glycoprotein that functions as the cellular receptor and catalytic cofactor for the serine protease factor VIIa. In human tumors, tissue factor expression correlates spatially with neovascularization, indicating that tissue factor function may be linked to angiogenic properties of malignant tumors. Tissue factor also supports hematogenous tumor dissemination. The role of tissue factor in metastasis appears to involve both the coagulation pathway triggered by interactions of the tissue factor extracellular domain as well as cellular events dependent on the short cytoplasmic domain that may participate in tissue factor-mediated outside-in signaling.

Topics: Humans; Neoplasm Metastasis; Neoplasms; Neovascularization, Pathologic; Thromboplastin

Thrombosis is the most frequent complication and the second cause of death in patients with overt malignant diseases. Increasing evidence suggests that thrombotic episodes may also precede the diagnosis of cancer by months or years thus representing a potential marker for occult malignancy. Recently, emphasis has been given to the potential risk of cancer therapy (both surgery and chemotherapy) in enhancing the risk for thromboembolic disease. Post-operative deep-vein thrombosis is indeed more frequent in patients operated for malignant diseases than for other disorders. On the other hand, both chemotherapy and hormone therapy are associated with an increased thrombotic risk, which can be prevented by low-dose oral anticoagulation. Possible contributory causes for thromboembolic disease in cancer include the capacity of tumor cells and their products to interact with platelets, clotting and fibrinolytic systems, as well as their interactions with endothelial cells and tumor-associated macrophages. In particular, procoagulant activities of tumor cells have been extensively studied; one of these, cancer procoagulant, could represent a novel marker of malignancy in both solid tumors and acute promyelocytic leukemia (APL). In solid tumors, CP, a vitamin K dependent enzyme could represent the selective target of the antimetastatic effects of warfarin treatment. In APL, CP may contribute to trigger the well known intravascular coagulation syndrome accompanying the early manifestations of the disease and is depressed by all-trans-retinoic acid, an agent capable to determine complete remission with a rapid amelioration of the bleeding syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Antineoplastic Agents; Cysteine Endopeptidases; Disease Models, Animal; Disease Progression; Hormones; Humans; Leukemia, Promyelocytic, Acute; Mice; Mice, Transgenic; Neoplasm Proteins; Neoplasms; Neoplasms, Experimental; Neoplasms, Unknown Primary; Plasminogen Activator Inhibitor 1; Thrombophlebitis; Thromboplastin

Tissue factor (TF) exists in a cryptic form [i.e. without procoagulant activity (PCA)] in peripheral blood monocytes and quiescent tissue macrophages but is expressed constitutively in most human tumor cells. Induction and cell surface expression of TF in these cells in vivo is associated with activation of intravascular and extravascular coagulation in patients with a variety of inflammatory or malignant diseases. The regulation of TF synthesis in cells is complex and new information from transfection studies suggests that changes in cellular glycosylation pathways impair cell surface expression of functional TF. Such dysregulation may also characterize the lineage-unfaithful expression of TF in leukemic cells and perhaps explain some of the thrombohemorrhagic complications in patients with acute progranulocytic leukemia. The importance of carbohydrate modification of TF is reviewed.

Topics: Acute Disease; Animals; Blood Coagulation Disorders; Carbohydrate Sequence; Cell Differentiation; CHO Cells; Cricetinae; Cricetulus; Cysteine Endopeptidases; Glycosylation; HL-60 Cells; Humans; Leukemia; Leukocytes; Molecular Sequence Data; Neoplasm Proteins; Neoplasms; Neoplastic Stem Cells; Thromboplastin

Inflammation and the cytokines clearly affect the coagulation system. Less clear are the specific influences of the coagulation system on inflammation. In this chapter only some of the coagulation systems affected by the cytokines are discussed, and the influences on the fibrinolytic system, which is also downregulated by selected cytokines are not mentioned; see Schneiderman and Loskutoff (1991) for a brief review. The major focus is on possible models by which inflammation and coagulation are linked, and examples where in vitro studies have led to correct in vivo predictions and where the results remain ambiguous. Finally, this chapter is clearly a biased perspective with the primary emphasis on the components and pathways with which the author has personal experience.

Topics: Animals; Blood Coagulation Factors; Cell Adhesion Molecules; Cells, Cultured; Cytokines; Disseminated Intravascular Coagulation; Endothelium, Vascular; Humans; Inflammation; Models, Biological; Neoplasms; Papio; Protein C; Shock, Septic; Thrombomodulin; Thromboplastin; Thrombosis

Tissue factor is a cell surface glycoprotein responsible for initiating the extrinsic pathway of coagulation. Many tumor cell homogenates and intact tumor cells have been shown to contain tissue factor activity. Immunohistochemical studies show that many tumors associated with Trousseau's syndrome express tissue factor on their cell surfaces. Tumor cells shed membrane fragments which carry tissue factor that can account for the activation of the clotting system. Tumor cells also produce soluble substances that can induce tissue factor expression on host cells, such as endothelium and monocytes, at sites distant from the tumor. Although, all the functional TF molecules are localized on the outer cell membrane in many tumor cells, the procoagulant activity on the intact cell surface is largely dormant and can be greatly enhanced upon cell injury or damage. Tissue factor procoagulant activity on the cell surface can be modulated by alterations in the plasma membrane without loss of cell viability. Tissue factor activity on cell surfaces is largely regulated by a plasma inhibitor, tissue factor pathway inhibitor. This inhibitor binds to both functional and non-functional tissue factor/VIIa complexes on the cell surface and prevents non-functional tissue factor/VIIa complexes from becoming functional after cell injury or lysis. Heparin, but not warfarin, therapy is effective in preventing the occurrence of devastating thrombotic events in patients with Trousseau's syndrome and the reason(s) for this are still unknown.

Topics: Gene Expression Regulation, Neoplastic; Humans; Lipoproteins; Neoplasms; Thromboplastin; Thrombosis

Topics: Blood Coagulation; Blood Coagulation Factors; Blood Flow Velocity; Blood Proteins; Cytokines; Endothelium, Vascular; HLA-D Antigens; Humans; Macrophages; Monocytes; Neoplasms; Thromboplastin; Thrombosis

Extrinsic pathway inhibitor (EPI) is a Kunitz type serine protease inhibitor. EPI is a potent inhibitor of the factor VIIa/thromboplastin (TP) complex in the presence of factor Xa and is also a direct inhibitor of factor Xa. The inhibitory mechanism is complex and is currently thought to involve, in a first step, the formation of a EPI-factor Xa complex, and, in a second step, the formation a quaternary EPI-factor Xa-factor VIIa-TP complex. In the blood vessels, EPI is confined to three different pools. A major pool of EPI is bound to the endothelial surface, and this fraction may be released by heparin. Plasma contains a second, but smaller pool of EPI (approximately 10-50% of the endothelial surface pool) at a concentration of 50-100 ng/ml. This pool consists mostly of EPI-lipoprotein complexes and only less than 10% is carrier-free EPI. A third pool of EPI is confined to platelets (less than 10% of the plasma pool). The biological role of these pools has not yet been clarified, but some evidence suggest that the carrier-free EPI is biologically most active. In patients, disseminated intravascular coagulation may continue despite normal or even elevated EPI levels. However, evidence has now been provided to indicate that EPI can inhibit factor VIIa/TP complexes formed in vivo to prevent the effect of limited amounts of TP. Taken together, the present knowledge of EPI indicates that EPI functions as a key inhibitor to feedback control of blood coagulation initiated by TP.

Topics: Blood Coagulation; Blood Platelets; Disseminated Intravascular Coagulation; Endothelium, Vascular; Factor VII; Factor VIIa; Factor Xa Inhibitors; Feedback; Heparin; Humans; Lipoproteins; Liver Diseases; Neoplasms; Recombinant Proteins; Reference Values; Sepsis; Thromboplastin

Peripheral blood monocytes generate the procoagulant tissue factor in vitro and in vivo in response to stimulation by a variety of agents. Monocytes from cancer patients generate significantly increased tissue factor and a quantitative relationship exists between the levels of monocyte tissue factor (MTF) and levels of circulating fibrinopeptide A (FPA), a marker of in vivo clotting activation. Furthermore, monocytes from cancer patients have a greater procoagulant response to stimulation by endotoxin in vitro, which appears independent of lymphocyte regulation. These findings suggest a priming process in vivo, and may reflect exposure of monocytes to tumor antigen(s) or components of the immune response to tumors.

Topics: Animals; Anticoagulants; Blood Coagulation Factors; Fibrinopeptide B; Humans; Monocytes; Neoplasms; Neoplasms, Experimental; Thromboplastin

Tissue factor (TF) is an integral membrane glycoprotein which functions as an initiator of coagulation. Furthermore, it is probably the principal biological initiator of this essential hemostatic process. This article reviews the studies which form the basis for these assertions. The work on TF is traced from the 19th century discovery of the thromboplastic activity of tissues to the recent purification of the protein from bovine and human tissues and the isolation cDNA clones coding from human TF. The features of TF structure and function which tailor it to the role of initiator of the coagulation cascade are considered. For example, cell-surface TF and factor VII, the plasma serine proteases zymogen, form a proteolytic complex without prior proteolysis of either component. In addition, a kinetic model for the molecular mechanism of TF-initiated clotting is reviewed. The factors which control the expression of TF procoagulant activity by cultured cells are examined in light of the hypothesized role of TF in normal hemostasis. Also, the potential pathological consequences of aberrant TF expression, i.e., thrombosis and hemorrhage, are explored.

Topics: Animals; Base Sequence; Blood Coagulation; Cells, Cultured; DNA, Recombinant; Enzyme Activation; Genes; Inflammation; Kinetics; Molecular Sequence Data; Neoplasms; Species Specificity; Thromboplastin

Mononuclear phagocytes, a specialized cell lineage comprising bone-marrow precursors, blood monocytes and tissue macrophages, can interact with blood coagulation mechanisms with resulting thrombus formation or extravascular fibrin accumulation. Such procoagulant activity is usually activation dependent and requires interaction of the cells with immune or nonimmune stimuli. In the former case (e.g., alloantigens, soluble protein antigens) collaboration of mononuclear phagocytes with T lymphocytes is necessary and is mediated by cell-to-cell contact or lymphokines. Prototype of a direct acting stimulus is bacterial lipopolysaccharide. Mononuclear phagocyte procoagulant activity is expressed in the form of cell membrane-bound or released factors which display molecular heterogeneity. They include the initiator of the extrinsic clotting pathway, tissue factor, known clotting proteases such as factors V and VII, and novel proteolytic enzymes including prothrombinase and a factor X activator. Mononuclear phagocyte procoagulants are pathogenetically involved in generalized disorders with intravascular coagulation and thromboembolic phenomena. These disorders, exemplified by the Shwartzman reaction and possibly by paraneoplastic thromboembolism, are initiated by blood monocytes. Extravascular fibrin deposition can be initiated by tissue-infiltrating monocytes and macrophages in disease states such as acute renal allograft failure and solid tumours.

Topics: Animals; Blood Coagulation Factors; Cell Communication; Disseminated Intravascular Coagulation; Graft Rejection; Humans; Hypersensitivity, Delayed; Inflammation; Macrophages; Neoplasms; T-Lymphocytes; Thromboplastin

Topics: Disseminated Intravascular Coagulation; Humans; Neoplasms; Thromboplastin

Topics: Autoantibodies; Autoimmune Diseases; Blood Coagulation Factors; Blood Coagulation Tests; Collagen Diseases; Drug Hypersensitivity; False Positive Reactions; Female; Hemorrhage; Humans; Immunoglobulin M; Lupus Coagulation Inhibitor; Lupus Erythematosus, Systemic; Male; Neoplasms; Pregnancy; Pregnancy Complications, Hematologic; Thromboplastin; Thrombosis

From the preceding exposition it is now clear that the regulation of monocyte/macrophage PCA is dependent upon a complex network of interacting pathways, some of which amplify the response of the monocyte/macrophage, while others inhibit. In all probability many more will emerge. The construct illustrated in Figure 3, therefore, is a simplified view of the two major stimulatory pathways: the T cell-dependent pathway, activated by immune recognition and mediated by lymphokine(s); and the T cell-independent pathway, activated by direct perturbation of monocytes by such stimuli as LPS. At least 2 or 3 different PCAs can be expressed by monocyte/macrophages from different species, depending upon the anatomic site of the origin of the cell and the types of stimuli imposed. Inhibition of PCA expression is accomplished by at least one set of regulatory lipoproteins, and other inhibitory loops may be found. The result of these multiple interactions is the deposition of fibrin on the cell surface or in the surrounding milieu. It is our belief that this close relationship between coagulation reactions and inflammatory reactions, resulting in fibrin deposition, represents a fundamental host defense designed to delimit the inflammatory response. Nevertheless, the precise role of monocyte procoagulants in vivo remains unclear. A number of potential mechanisms exist for activation of coagulation in both inflammatory and neoplastic disorders, and the finding of enhanced monocyte procoagulant activity by no means establishes its importance in physiologic or, pathosphysiologic responses in vivo. Further studies, possibly with agents capable of specific inhibition of monocyte procoagulants in vivo, will be necessary to define the precise importance of these procoagulants in clinical disorders.

Topics: Animals; Anti-Inflammatory Agents; Antigens; Blood Coagulation; Blood Coagulation Factors; Cell Line; Factor V; Factor VII; Factor X; Factor Xa; Fibrin; Fibrin Fibrinogen Degradation Products; Guinea Pigs; Humans; Hypersensitivity, Delayed; Immunologic Deficiency Syndromes; Infections; Inflammation; Lipopolysaccharides; Macrophages; Mice; Monocytes; Neoplasms; Neutrophils; Rabbits; Rats; T-Lymphocytes; Thromboembolism; Thromboplastin; Warfarin

Topics: Anticoagulants; Blood Coagulation Disorders; Blood Platelets; Disseminated Intravascular Coagulation; Factor X; Fibrin; Fibrinolysis; Humans; Neoplasms; Neovascularization, Pathologic; Thrombophlebitis; Thromboplastin

Topics: Blood Coagulation; Fibrinogen; Humans; Neoplasms; Phlebitis; Platelet Aggregation; Thromboembolism; Thromboplastin

The macrophage is the characteristic cell type in chronic inflammatory reactions, in the rheumatoid synovium, as in other sites. When macrophages are activated, considerable synthesis of enzymes and other proteins occurs. Macrophages can be activated by (i) products of activated lymphocytes, (ii) immune complexes and (iii) the complement cleavage product C3b. Among the many consequences of macrophage activation are (i) secretion of hydrolytic enzymes, (ii) cleavage of C3 into C3a, which is cytolytic, and C3b, (iii) production of tissue thromboplastin, a powerful procoagulant, and (iv) formation of polyamine oxidase, which in the presence of appropriate substrates generates factors that lyse or limit the proliferation of tumour cells, lymphocytes and micro-organisms. The relevance of these observations to the pathogenesis of chronic inflammatory reactions is discussed.

Topics: Animals; Cells, Cultured; Chronic Disease; Colony-Stimulating Factors; Complement System Proteins; Erythrocyte Aggregation; Guinea Pigs; Humans; In Vitro Techniques; Inflammation; Interferons; Macrophages; Mice; Neoplasms; Plasminogen Activators; Prostaglandins; Pyrogens; T-Lymphocytes; Thromboplastin

Topics: Adjuvants, Immunologic; Animals; Antigen-Antibody Complex; Bacteriolysis; Bone Marrow Cells; Cell Differentiation; Complement System Proteins; Endotoxins; Eukaryota; Fibrinogen; Humans; Immunity, Innate; Interferon Inducers; Interferons; Lymphokines; Macrophages; Neoplasms; Phagocytosis; Plasminogen Activators; Prostaglandins; Pyrogens; T-Lymphocytes; Thromboplastin

Topics: Anticoagulants; Disseminated Intravascular Coagulation; Fetal Blood; Fibrin Fibrinogen Degradation Products; Fibrinolysis; Humans; Infant, Newborn; Kidney Diseases; Neoplasms; Thromboembolism; Thromboplastin

Topics: Blood Coagulation; Fibrin; Fibrinogen; Fibrinolysis; Hemorrhage; Heparin; Humans; Neoplasm Metastasis; Neoplasms; Thromboplastin; Thrombosis

Thrombophlebitis has been associated with virtually all cancers, especially gastrointestinal, urogenital, and lung neoplasms. Although occurring infrequently in cancer patients, thrombophlebitis may appear before the cancer has become symptomatic and may lead to an earlier diagnosis of cancer. The phlebitic syndrome associated with cancer, although not unique, is distinctive. It is often recurrent and migratory, often involves unusual locations, and is often resistant to anticoagulation therapy. Pulmonary emboli are frequent complications. The pathogenesis of phlebitis in cancer patients is not well understood. Evidence suggests that many cancer patients are hypercoagulable, with abnormalities in platelets, coagulation factors, and the fibrinolytic system. These changes may results from the elaboration of thromboplastin-like substances from the cancer tissue.

Topics: Blood Coagulation; Fibrinolysis; Humans; Neoplasms; Pancreatic Neoplasms; Prognosis; Thrombophlebitis; Thromboplastin

Topics: Animals; Aorta; Autoradiography; Basement Membrane; Blood Vessels; Embolism; Endothelium; Fibrin; Fibrinolysis; HeLa Cells; Humans; Microscopy, Electron; Mitosis; Neoplasm Metastasis; Neoplasms; Neoplasms, Experimental; Neoplastic Cells, Circulating; Plasminogen; Platelet Adhesiveness; Saphenous Vein; Thromboplastin; Thymidine; Tritium

Topics: Adolescent; Adult; Blood Coagulation; Blood Coagulation Disorders; Child; Disseminated Intravascular Coagulation; Embolism, Fat; Endotoxins; Fatty Acids; Female; Fibrinolysis; Heart Defects, Congenital; Hemangioma; Hemolysis; Humans; Leukemia; Male; Middle Aged; Mononuclear Phagocyte System; Neoplasms; Pregnancy; Pregnancy Complications; Purpura, Thrombocytopenic; Skin Neoplasms; Thromboplastin

Topics: Animals; Anticoagulants; Blood Coagulation Factors; Fibrin; Hemostatics; Lymphatic Metastasis; Neoplasms; Neoplasms, Experimental; Thromboplastin

Essentials Statins lower venous thromboembolism risk in general but have not been studied in cancer patients. We completed a randomized trial of rosuvastatin vs. placebo among cancer patients on chemotherapy. Rosuvastatin did not significantly lower prothrombotic biomarkers including D-dimer. The role of statins in venous thrombosis prevention in cancer patients remains unknown.. Background Statin therapy is associated with lower risk of venous thromboembolism (VTE) but has not been prospectively evaluated in patients with advanced cancer. Objectives We determined if statin administration in this high-risk population reduces the risk of VTE, based on established and emerging biomarkers. Patients/Methods This double-blind, crossover, randomized controlled trial among patients with advanced cancer receiving systemic therapy allocated participants to rosuvastatin 20 mg daily or placebo for 3-4 weeks prior to crossover to the alternative therapy, with a 3-5-week washout. D-dimer, C-reactive protein (CRP), soluble (s)P-selectin, factor VIII (FVIII), thrombin generation and exploratory biomarkers focusing on endogenous thrombin potential, including tissue factor (TF), activated factor IX (FIXa) and activated factor XI (FXIa), were measured at the start and end of both treatment periods. The primary outcome was change in D-dimer with rosuvastatin compared with placebo. Results Of 38 enrolled participants, 24 (63%) completed the study. Rosuvastatin did not cause statistically significant changes in D-dimer levels or any other biomarker. CRP levels decreased by 40%; 4.3 mg L

Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Agents; Biomarkers; C-Reactive Protein; Cross-Over Studies; Double-Blind Method; Factor IXa; Factor VIII; Factor XIa; Female; Fibrin Fibrinogen Degradation Products; Fibrinolytic Agents; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Male; Middle Aged; Neoplasms; P-Selectin; Risk Factors; Rosuvastatin Calcium; Thrombin; Thromboplastin; Time Factors; Treatment Outcome; Venous Thromboembolism; Vermont

Purpose Circulating tissue factor (TF) has been studied as a biomarker for predicting initial, but not recurrent, venous thromboembolism (VTE) in cancer, a setting in which predictors are incompletely understood. We evaluated the association of TF, clinical risk factors, and other biomarkers measured at the time of initial VTE with recurrent VTE in a prespecified analysis of the CATCH (Comparison of Acute Treatments in Cancer Hemostasis) trial. Methods CATCH was a randomized, multicenter trial that investigated tinzaparin 175 IU/kg once daily or dose-adjusted warfarin for 6 months in patients with cancer and acute, symptomatic VTE. TF ELISA, soluble P-selectin, d-dimer, FVIII, and C-reactive protein were assayed. Fisher's exact test was used to screen for association with VTE; competing risk regression analysis of time to recurrent VTE was conducted, accounting for multiple variables. Results The study population comprised 900 patients (recurrent VTE, n = 76; 8.4%). Of these patients, 805 had samples available for TF assay. Mean and median TF levels were 72.5 pg/mL and 50.3 pg/mL, respectively (range, 15.6 pg/mL to 4,798 pg/mL). Patients in the highest quartile of TF experienced the greatest VTE recurrence (> 64.6 pg/mL; 38 [19%] of 203 patients v 34 [6%] of 602 patients; relative risk, 3.3; 95% CI, 2.1 to 5.1; P < .001). In competing risk regression analysis of time to recurrent VTE, TF remained strongly associated with recurrent VTE (subdistribution hazard ratio [SHR], 3.3; 95% CI, 1.7 to 6.4). Other significant variables included venous compression from mass (SHR, 3.1; 95% CI, 1.4 to 6.5) and hepatobiliary cancer (SHR, 5.5; 95% CI, 2.3 to 13.6). Conclusion This is the first report, to our knowledge, to describe TF as a potential biomarker of recurrent VTE in patients with cancer who are on anticoagulation treatment. A risk-adapted strategy could help identify high-risk patients who may benefit from more intensive anticoagulation approaches.

Topics: Aged; Biomarkers; C-Reactive Protein; Factor VIII; Fibrin Fibrinogen Degradation Products; Fibrinolytic Agents; Heparin, Low-Molecular-Weight; Humans; Neoplasms; P-Selectin; Predictive Value of Tests; Prospective Studies; Recurrence; Risk Factors; Thromboplastin; Time Factors; Tinzaparin; Venous Thromboembolism

Cancer and stroke, which are known to be associated with one another, are the most common causes of death in the elderly. However, the pathomechanisms that lead to stroke in cancer patients are not well known. Circulating extracellular vesicles (EVs) play a role in cancer-associated thrombosis and tumor progression. Therefore, we hypothesized that cancer cell-derived EVs cause cancer-related coagulopathy resulting in ischemic stroke.. Serum levels of D-dimer and EVs expressing markers for cancer cells (epithelial cell adhesion molecule [CD326]), tissue factor (TF [CD142]), endothelial cells (CD31+CD42b-), and platelets (CD62P) were measured using flow cytometry in (a) 155 patients with ischemic stroke and active cancer (116 - cancer-related, 39 - conventional stroke mechanisms), (b) 25 patients with ischemic stroke without cancer, (c) 32 cancer patients without stroke, and (d) 101 healthy subjects.. The levels of cancer cell-derived EVs correlated with the levels of D-dimer and TF+ EVs. The levels of cancer cell-derived EVs (CD326+ and CD326+CD142+) were higher in cancer-related stroke than in other groups (P<0.05 in all the cases). Path analysis showed that cancer cell-derived EVs are related to stroke via coagulopathy as measured by D-dimer levels. Poor correlation was observed between TF+ EV and D-dimer, and path analysis demonstrated that cancer cell-derived EVs may cause cancer-related coagulopathy independent of the levels of TF+ EVs.. Our findings suggest that cancer cell-derived EVs mediate coagulopathy resulting in ischemic stroke via TF-independent mechanisms.

Topics: Aged; Disseminated Intravascular Coagulation; Extracellular Vesicles; Female; Fibrin Fibrinogen Degradation Products; Humans; Male; Middle Aged; Neoplasms; Stroke; Thromboplastin

Elevated levels of circulating tissue factor-bearing microparticles (TFMP) have been associated with an increased risk of developing venous thromboembolism (VTE) in cancer patients. We performed a randomized phase II study to evaluate the cumulative incidence of VTE in advanced cancer patients with lower levels of TFMP not receiving thromboprophylaxis and those with higher levels of circulating TFMP randomized to enoxaparin or observation. The cumulative incidence of VTE at 2 months in the higher TFMP group randomized to enoxaparin (N = 23) was 5·6% while the higher TFMP group observation arm (N = 11) was 27·3% (Gray test P = 0·06). The cumulative incidence of VTE in the low TFMP was 7·2% (N = 32). No major haemorrhages were observed in the enoxaparin arm. The median survival for patients with higher levels of TFMP followed by observation was 11·8 months compared with 17·8 months on enoxaparin (P = 0·58). In a prospective randomized trial, increased numbers of circulating TFMP detected by impedance flow cytometry identified cancer patients with a high incidence of VTE. Enoxaparin demonstrated a clear trend towards reducing the rate of VTE in patients with elevated levels of TFMP, with an overall rate of VTE similar in magnitude to the lower TFMP group.

Topics: Aged; Aged, 80 and over; Anticoagulants; Cell-Derived Microparticles; Enoxaparin; Female; Fibrin Fibrinogen Degradation Products; Humans; Male; Middle Aged; Neoplasms; Survival Analysis; Thromboembolism; Thromboplastin

We induced thrombosis of blood vessels in solid tumors in mice by a fusion protein consisting of the extracellular domain of tissue factor (truncated tissue factor, tTF) and the peptide GNGRAHA, targeting aminopeptidase N (CD13) and the integrin alpha(v)beta(3) (CD51/CD61) on tumor vascular endothelium. The designed fusion protein tTF-NGR retained its thrombogenic activity as demonstrated by coagulation assays. In vivo studies in mice bearing established human adenocarcinoma (A549), melanoma (M21), and fibrosarcoma (HT1080) revealed that systemic administration of tTF-NGR induced partial or complete thrombotic occlusion of tumor vessels as shown by histologic analysis. tTF-NGR, but not untargeted tTF, induced significant tumor growth retardation or regression in all 3 types of solid tumors. Thrombosis induction in tumor vessels by tTF-NGR was also shown by contrast enhanced magnetic resonance imaging (MRI). In the human fibrosarcoma xenograft model, MRI revealed a significant reduction of tumor perfusion by administration of tTF-NGR. Clinical first-in-man application of low dosages of this targeted coagulation factor revealed good tolerability and decreased tumor perfusion as measured by MRI. Targeted thrombosis in the tumor vasculature induced by tTF-NGR may be a promising strategy for the treatment of cancer.

Topics: Adult; Angiogenesis Inhibitors; Animals; Cells, Cultured; Drug Delivery Systems; Embolism; Female; Humans; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Middle Aged; Neoplasms; Neovascularization, Pathologic; Oligopeptides; Salvage Therapy; Thromboplastin; Xenograft Model Antitumor Assays

Immunotherapy for breast cancer has not gained significant success. Coagulation factor VIIa (FVIIa)-tissue factor (TF) mediated activation of protease-activated receptor 2 (PAR2) is shown to promote metastasis and secretion of the immune-modulatory cytokines but the role of FVIIa in cancer immunology is still not well understood.. Here, we aim to investigate whether FVIIa protects breast cancer cells from CD8 T-cell-mediated killing.. Peripheral blood mononuclear cell-derived CD8 T cells were cocultured with vehicle or FVIIa pretreated MDAMB468 cells. The proliferation and activity of CD8 T cells were measured by flow cytometry and ELISA. An allograft model, using wild-type or TF/PAR2-deleted 4T1 cells, was employed to determine the effect of FVIIa on breast cancer immune evasion in vivo.. Here, we demonstrate that TF-FVIIa induces programmed death-ligand 1 (PD-L1) in breast cancer cells by activating PAR2. PAR2 activation triggers large tumor suppressor kinase 1 (LATS1) inactivation leading to loss of yes-associated protein (YAP)/transcriptional coactivator with PDZ-binding motif (TAZ) phosphorylation and subsequent nuclear localization of YAP/TAZ. YAP/TAZ inhibition reduces PD-L1 expression and increases CD8 T-cell activity. We further demonstrate that, apart from transcriptional induction of PD-L1, PAR2 activation also increases PD-L1 stability by enhancing its glycosylation through N-glycosyltransferases STT3A and STT3B.. In a mouse model of breast cancer, tumor cell-specific PAR2 depletion leads to PD-L1 downregulation and increases anti-PD-1 immunotherapy efficacy. In conclusion, we showed that FVIIa-mediated signaling cascade in cancer cells serves as a tumor intrinsic mechanism of immunosuppression to promote cancer immune evasion.

Topics: Animals; B7-H1 Antigen; Cell Line, Tumor; Factor VIIa; Immune Evasion; Leukocytes, Mononuclear; Mice; Neoplasms; Receptor, PAR-2; Thromboplastin

Synergetic therapy includes the combination of two or more conventional therapeutic approaches and can be used for tumor treatment by combining the advantages and avoiding the drawbacks of each type of treatment. In the present study, truncated tissue factor (tTF)-EG3287 fusion protein-encapsulated gold nanorod (GNR)-virus-inspired mesoporous silica core-shell nanoparticles (vinyl hybrid silica nanoparticles; VSNP) (GNR@VSNP-tTF-EG3287) were synthesized to achieve synergetic therapy by utilizing selective vascular thrombosis therapy (SVTT) and photothermal therapy (PTT). By integrating the targeted coagulation activity of tTF-EG3287 and the high tumor ablation effect of GNR@VSNP, local hyperthermia could induce a high percentage of apoptosis of vascular endothelial cells by using near-infrared light. This provided additional phospholipid sites for tTF-EG3287 and enhanced its procoagulant activity

Topics: Animals; Antineoplastic Agents; Apoptosis; Coagulants; Female; Gold; Hep G2 Cells; Human Umbilical Vein Endothelial Cells; Humans; Infrared Rays; Mice, Inbred BALB C; Mice, Nude; Nanotubes; Neoplasms; Peptide Fragments; Photothermal Therapy; Porosity; Rabbits; Recombinant Fusion Proteins; Silicon Dioxide; Thromboplastin; Thrombosis; Vascular Endothelial Growth Factor A; Xenograft Model Antitumor Assays

GST omega 1 (GSTO1) is an atypical GST isoform that is overexpressed in several cancers and has been implicated in drug resistance. Currently, no small-molecule drug targeting GSTO1 is under clinical development. Here we have validated GSTO1 as an impactful target in oncology. Transcriptional profiling coupled with proteomics uncovered novel pharmacodynamic markers and cellular pathways regulated by GSTO1. CRISPR/Cas9 GSTO1 knockout (KO) cell lines failed to form tumors or displayed growth delay

Topics: Animals; Down-Regulation; Female; Gene Expression Regulation, Neoplastic; Glutathione Transferase; Heterografts; Humans; Interferon Type I; Mice; Mice, Inbred NOD; Mice, SCID; Neoplasms; Thromboplastin

The relationship between cancer and venous thromboembolic disease (VTD) are complex because the activated coagulation factors are not only involved in thrombosis but also in malignant processes, such as angiogenesis and metastasis.. To compare phenotypes of extracellular vesicles (EVs), and levels of D-dimer, soluble P-selectin (sP-selectin) and antigenic tissue factor (TF) between unprovoked VTD patients, who did not develop cancer during one-year follow-up, and those with advanced stage of cancer but not associated with VTD.. A prospective study in which we included 138 unprovoked VTD patients and 67 advanced cancer patients, who did not develop thrombosis. Levels of EVs of different cellular origin (platelet, endothelium and leukocyte), EVs positive for tissue factor (TF) and P-selectin glycoprotein ligand 1 were quantified by flow cytometry. D-dimer, soluble P-selectin (sP-selectin) and antigenic TF were determined by ELISA.. TF-positive EVs, D-dimer, and sP-selectin were markedly elevated in unprovoked VTD patients compared to cancer patients without association with thrombosis.. Levels of TF-positive EVs, D-dimer and sP-selectin are able to discriminate between unprovoked VTD patients not related to cancer and cancer patients not associated with VTD. These results could lead to the application of EVs as biomarkers of both diseases.

Topics: Aged; Biomarkers; Case-Control Studies; Extracellular Vesicles; Female; Fibrin Fibrinogen Degradation Products; Humans; Male; Membrane Glycoproteins; Middle Aged; Neoplasms; Prospective Studies; Thromboembolism; Thromboplastin

Topics: Extracellular Vesicles; Humans; Neoplasms; Risk Factors; Thromboplastin; Venous Thromboembolism

Malignant tumor is one of the important acquired risk factors of venous thromboembolism (VTE). As the transmembrane receptor of coagulation factor Ⅶ and activated coagulation factor Ⅶa

Topics: Humans; Neoplasms; Risk Factors; Thromboplastin; Thrombosis; Venous Thromboembolism

Hypercoagulability is a common paraneoplastic complication in dogs with various malignant tumors. Importantly, tissue factor procoagulant activity (TF-PCA) induced by TF-bearing microparticles (TF-MPs) is associated with hypercoagulability in human patients with cancer. However, TF-PCA in tumor cells and the association between circulating TF-MPs and hypercoagulability in dogs with malignant tumors remain poorly understood. Therefore, the present study was conducted to evaluate the TF-PCA in various types of canine tumor cell lines and plasma in dogs with malignant tumors. Mammary gland tumor, hemangiosarcoma, and malignant melanoma cell lines, but not lymphoma cell lines, expressed TF on their surfaces and showed cellular surface and MP-associated TF-PCA. The plasma TF-PCA was elevated in some dogs that naturally developed such tumors. No significant difference was observed in plasma TF-PCA between the disseminated intravascular coagulation (DIC) group (median: 43.40; range: 3.47-85.19; n=5) and non-DIC group (median: 7.73; range: 1.70-16.13; n=12). However, plasma TF-PCA was remarkably elevated in three of five dogs with DIC. To the best of our knowledge, this is the first study to evaluate plasma TF-PCA in dogs with malignant tumors. Further studies must be conducted to determine the cellular origin of TF-MPs and the efficacy of plasma TF-PCA as a biomarker of DIC in dogs with malignant tumors.

Topics: Animals; Cell Line, Tumor; Cell-Derived Microparticles; Dog Diseases; Dogs; Female; Flow Cytometry; Hemangiosarcoma; Lymphoma; Mammary Neoplasms, Animal; Melanoma; Neoplasms; Thromboplastin

Topics: Animals; Disease Models, Animal; Evolution, Molecular; Mice; Neoplasms; Receptors, Aryl Hydrocarbon; Thromboplastin

Topics: Biomarkers; Cell-Derived Microparticles; Humans; Neoplasms; Postthrombotic Syndrome; Risk Factors; Thromboplastin; Venous Thrombosis

Tissue factor (TF) expressed at the protein level includes two isoforms: The membrane‑bound full‑length TF (flTF) and the soluble alternatively spliced TF (asTF). flTF is the major thrombogenic form of TF, whereas asTF is more closely associated with tumor growth, angiogenesis, metastasis and cell growth. In order to further investigate the different expression and functions of TF splice variants, the expression of these two splice variants were detected in numerous cell strains and tissues in the present study. Quantitative polymerase chain reaction was used to measure the transcript levels of the TF variants in 11 human cell lines, including cervical cancer, breast cancer, hepatoblastoma, colorectal cancer and umbilical vein cells, and five types of tissue specimen, including placenta, esophageal cancer, breast cancer, cervical cancer (alongside normal cervical tissues) and non‑small cell lung cancer (alongside adjacent and normal tissues). Furthermore, the effects of chenodeoxycholic acid (CDCA) and apolipoprotein M (apoM) on the two variants were investigated. The results demonstrated that flTF was the major form of TF, and the mRNA expression levels of flTF were higher than those of asTF in all specimens tested. CDCA significantly upregulated the mRNA expression levels of the two variants. Furthermore, overexpression of apoM promoted the expression levels of asTF in Caco‑2 cells. The mRNA expression levels of asTF in cervical cancer tissues were significantly higher than in the corresponding normal tissues. To the best of our knowledge, the present study is the first to compare the expression of flTF and asTF in various samples. The results demonstrated that CDCA and apoM may modulate TF isoforms in different cell lines, and suggested that asTF may serve a role in the pathophysiological mechanism underlying cervical cancer development. In conclusion, the TF isoforms serve important and distinct roles in pathophysiological processes.

Topics: Alternative Splicing; Apolipoproteins M; Caco-2 Cells; Cell Proliferation; Chenodeoxycholic Acid; Female; Humans; Male; Neoplasms; Neovascularization, Pathologic; Protein Isoforms; RNA Splicing; Thromboplastin

Topics: Angiogenesis Inhibitors; Antibodies, Monoclonal; Humans; Immunoconjugates; Neoplasms; Thromboplastin

Cancer patients with Tissue Factor (TF)-bearing MPs have been presented association with increased risk of venous thromboembolism (VTE), but results of these studies have not been consistent. We aimed to conduct a meta-analysis to assess the relationship between TF-bearing MPs and risk of VTE in patients with cancer. PubMed, Web of Science and EMBASE Databases were systematically retrieved up to1

Topics: Cell-Derived Microparticles; Humans; Neoplasms; Risk Assessment; Thromboplastin; Venous Thrombosis

The procoagulant activity of extracellular vesicles (EV) exposing tissue factor (TF) is a promising biomarker for venous thromboembolism (VTE) in cancer patients. We evaluated an in-house EV-TF activity assay (the fibrin generation test) for the prediction of cancer-associated VTE. We also compared the results with the fibrin generation tests to an EV-TF-dependent factor Xa generation assay in samples from pancreatic cancer patients.. Data collected in a multinational, prospective cohort study were used. Patients with various types of advanced cancer were enrolled if chemotherapy was scheduled or started in the previous 3 months. Patients were followed for 6 months for the occurrence of VTE. The fibrin generation test was performed at baseline to measure EV-TF procoagulant activity.. The fibrin generation test was performed in 648 patients with advanced cancer. The mean age was 62 years; 58% had distant metastasis. Forty patients (6.1%) developed VTE. Overall, a high fibrin generation test result was associated with a two-fold increased risk for VTE (HR 2.0; 95%-CI, 1.1-3.6). The association was stronger in patients with pancreatic cancer (HR 4.1; 95%-CI, 0.91-19) than in those with other tumor types (HR 1.5; 95%-CI, 0.72-3.1). Correlation between the FGT and the TF-dependent factor Xa generation assay in patients with pancreatic cancer was poor (Spearman's R = 0.35).. This study shows that a high EV-TF procoagulant activity as measured by the fibrin generation test is associated with an increased risk of VTE in cancer patients, in particular in those with pancreatic cancer. Future studies should aim to further improve the feasibility and accuracy of EV-TF activity assays.

Topics: Cohort Studies; Extracellular Vesicles; Female; Humans; Male; Middle Aged; Neoplasms; Prospective Studies; Thromboplastin; Venous Thromboembolism

Thrombosis is frequently diagnosed as a first symptom in tumor patients and the clinical management of hypercoagulability in cancer patients remains challenging due to concomitant changes in risk factors for severe bleeding. It therefore remains a priority to better understand interactions of the hemostatic system with cancer biology. Specifically, further research is needed to elucidate the details and effects of new anticoagulants on extravascular coagulation and the interplay between cancer progression and chronic inflammation. In addition, it will be important to identify subgroups of cancer patients benefiting from specific modulations of the coagulation system without increasing the bleeding risk. Here, we review recent findings on tissue factor (TF) regulation, its procoagulant activity and TF signaling in the various cell types of the tumor microenvironment.

Topics: Blood Coagulation; Chronic Disease; Humans; Inflammation; Neoplasms; Signal Transduction; Thromboplastin; Tumor Microenvironment

Targeting the human blood coagulation-inducing protein tissue factor (TF) to the tumor vasculature to induce infarction and disrupt the blood vessels has proven to be an effective approach for tumor therapy. In this study, we investigated the thrombogenic activity and anti-tumor potential of a novel fusion protein (tTF-CREKA) comprising the extracellular domain of human tissue factor (truncated TF, tTF) and a tumor targeting pentapeptide, Cys-Arg-Glu-Lys-Ala (CREKA). tTF is soluble and inactive in its free state, but when it is targeted to the plasma membrane of both tumor vessel endothelial cells and stromal cells by the CREKA peptide, its native coagulation-inducing activity is restored. Systemic administration of the tTF-CREKA fusion protein into tumor-bearing mice induced tumor-selective intravascular thrombosis and reduced tumor blood perfusion, consequently inhibiting tumor growth. The development of tTF-CREKA introduces a new method for treating a wide spectrum of solid tumors by selectively blocking tumor blood supply.

Topics: Animals; Cell Line, Tumor; Cloning, Molecular; Drug Delivery Systems; Hemostatics; Infarction; Mice, Inbred BALB C; Mice, Nude; Neoplasms; Neovascularization, Pathologic; Recombinant Proteins; Thromboplastin; Xenograft Model Antitumor Assays

Topics: Biomarkers; Humans; Neoplasms; Thromboplastin; Thrombosis; Venous Thromboembolism

Chemotherapy induces the release of apoptotic vesicles (ApoV) from the tumor plasma membrane. Tumor ApoV may enhance the risk of thrombotic events in cancer patients undergoing chemotherapy. However, the relative contribution of ApoV to coagulation and the pathways involved remain poorly characterized. In addition, this study sets out to compare the procoagulant activity of chemotherapy-induced ApoV with their cell of origin and to determine the mechanisms of ApoV-induced coagulation.. We utilized human and murine cancer cell lines and chemotherapeutic agents to determine the requirement for the coagulation factors (tissue factor; TF, FII, FV, FVII, FVIII, FIX and phosphatidylserine) in the procoagulant activity of ApoV. The role of previously identified ApoV-associated FV was determined in a FV functional assay.. ApoV were significantly more procoagulant per microgram of protein compared to parental living or dying tumor cells. In the phase to peak fibrin generation, procoagulant activity was dependent on phosphatidylserine, TF expression, FVII and the prothrombinase complex. However, the intrinsic coagulation factors FIX and FVIII were dispensable. ApoV-associated FV could not support coagulation in the absence of supplied, exogenous FV.. ApoV are significantly more procoagulant than their parental tumor cells. ApoV require the extrinsic tenase and prothrombinase complex to activate the early phase of coagulation. Endogenous FV identified on tumor ApoV is serum-derived and functional, but is non-essential for ApoV-mediated fibrin generation.. This study clarifies the mechanisms of procoagulant activity of vesicles released from dying tumor cells.

Topics: Animals; Antineoplastic Agents; Apoptosis; Blood Coagulation; Blood Coagulation Factors; Cell-Derived Microparticles; Cysteine Endopeptidases; Factor V; Factor Xa; Humans; MCF-7 Cells; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Neoplasm Proteins; Neoplasms; Phosphatidylserines; Thrombin; Thromboplastin

Topics: Biomarkers; Databases, Genetic; Humans; Neoplasms; Thromboplastin; Venous Thromboembolism

ESSENTIALS: Cancer patients have a high rate of venous thrombosis (VT) but the underlying mechanisms are unknown. Tumor-derived, tissue factor-positive microvesicles in platelet activation in vitro and in vivo were studied. Tumor-derived, tissue factor-positive microvesicles enhanced VT in mice. Platelets may contribute to VT in some cancer patients, and this could be prevented with antiplatelet drugs.. Cancer patients have an approximately 4-fold increased risk of venous thromboembolism (VTE) compared with the general population, and cancer patients with VTE have reduced survival. Tumor cells constitutively release small membrane vesicles called microvesicles (MVs) that may contribute to thrombosis in cancer patients. Clinical studies have shown that levels of circulating tumor-derived, tissue factor-positive (TF(+) ) MVs in pancreatic cancer patients are associated with VTE. Objectives We tested the hypothesis that TF(+) tumor-derived MVs (TMVs) activate platelets in vitro and in mice.. We selected two human pancreatic adenocarcinoma cell lines expressing high (BxPc-3) and low (L3.6pl) levels of TF as models to study the effect of TF(+) TMVs on platelets and thrombosis.. We found that both types of TF(+) TMVs activated human platelets and induced aggregation in vitro in a TF and thrombin-dependent manner. Further, injection of BxPc-3 TF(+) TMVs triggered platelet activation in vivo and enhanced thrombosis in two mouse models of venous thrombosis in a TF-dependent manner. Importantly, BxPc-3 TF(+) TMV-enhanced thrombosis was reduced in Par4-deficient mice and in wild-type mice treated with clopidogrel, suggesting that platelet activation was required for enhanced thrombosis. These studies suggest that TF(+) TMV-induced platelet activation contributes to thrombosis in cancer patients.

Topics: Adenocarcinoma; Animals; Blood Platelets; Cell Line, Tumor; Cell-Derived Microparticles; Clopidogrel; Female; Flow Cytometry; Humans; Mice; Mice, Inbred C57BL; Neoplasms; Pancreatic Neoplasms; Platelet Activation; Platelet Aggregation; Platelet Aggregation Inhibitors; Pulmonary Embolism; Thrombin; Thromboplastin; Thrombosis; Ticlopidine

tTF-TAA and tTF-LTL are fusion proteins consisting of the extracellular domain of tissue factor (TF) and the peptides TAASGVRSMH and LTLRWVGLMS, respectively. These peptides represent ligands of NG2, a surface proteoglycan expressed on angiogenic pericytes and some tumor cells. Here we have expressed the model compound tTF-NGR, tTF-TAA, and tTF-LTL with different lengths in the TF domain in E. coli and used these fusion proteins for functional studies in anticancer therapy. We aimed to retarget TF to tumor vessels leading to tumor vessel infarction with two barriers of selectivity, a) the leaky endothelial lining in tumor vessels with the target NG2 being expressed on pericytes on the abluminal side of the endothelial cell barrier and b) the preferential expression of NG2 on angiogenic vessels such as in tumors. Chromatography-purified tTF-TAA showed identical Factor X (FX)-activating procoagulatory activity as the model compound tTF-NGR with Km values of approx. 0.15 nM in Michaelis-Menten kinetics. The procoagulatory activity of tTF-LTL varied with the chosen length of the TF part of the fusion protein. Flow cytometry revealed specific binding of tTF-TAA to NG2-expressing pericytes and tumor cells with low affinity and dissociation KD in the high nM range. In vivo and ex vivo fluorescence imaging of tumor xenograft-carrying animals and of the explanted tumors showed reduction of tumor blood flow upon tTF-TAA application. Therapeutic experiments showed a reproducible antitumor activity of tTF-TAA against NG2-expressing A549-tumor xenografts, however, with a rather small therapeutic window (active/toxic dose in mg/kg body weight).

Topics: Animals; Antigens; Cell Line, Tumor; Endothelial Cells; Female; Humans; Mice; Mice, Nude; Molecular Targeted Therapy; Neoplasms; Neovascularization, Pathologic; Oligopeptides; Pericytes; Proteoglycans; Recombinant Fusion Proteins; Thromboplastin; Xenograft Model Antitumor Assays

Topics: Antithrombins; Blood Coagulation; Female; Humans; Neoplasms; Pre-Eclampsia; Pregnancy; Thromboplastin; Thrombosis

Angiogenesis represents one aspect in the complex process that leads to the generation of the vascular tumor stroma. The related functional constituents include responses of endothelial, mural, bone marrow-derived, and resident inflammatory cells as well as activation of coagulation and fibrinolytic systems in blood. Multiple molecular and cellular effectors participate in these events, often in a tumor-specific manner and with changes enforced through the microenvironment, genetic evolution, and responses to anticancer therapies. To capture various elements of these interactions several surrogate assays have been devised, which can be mechanistically useful and are amenable to quantification, but are individually insufficient to describe the underlying complexity and are best used in a targeted and combinatorial manner. Below, we present a survey of angiogenesis assays and experimental approaches to analyze vascular events in cancer. We also provided specific examples of validated protocols, which are less described, but enable the straightforward analysis of vascular structures and coagulant properties of cancer cells in vivo and in vitro.

Topics: Animals; Biomarkers; Blood Coagulation; Endothelial Cells; Fluorescent Antibody Technique; Humans; Immunohistochemistry; Neoplasms; Neovascularization, Pathologic; Thromboplastin; Tumor Microenvironment

Venous thromboembolism (VTE) is one of the most common complications in cancer patients. Although factor V Leiden (FVL) is the most common genetic defect causing thrombosis, the impact of gene abnormalities on thrombotic tendency in cancer patients remains poorly explored. Tissue factor (TF) is a major physiologic initiator of blood coagulation. This is the first study regarding the association of TF gene -603A/G and +5466A>G polymorphisms with VTE in malignancy. Materials and Me-thods: The study consists of two groups: cancer patients with VTE were included as Group 1 (n = 46); Group 2 comprises 196 cancer patients without VTE. Restriction fragment length polymorphism method was used for the detection of polymorphisms of TF -603A/G in the 5՛upstream region and TF 5466A/G in intron 2. FVL, PT G20210A and MTHFR C677T polymorphisms were determined by using commercially available Light Cycler kits. The genotype and allele frequencies between the groups were compared using χ2 or Fisher exact test, if appropriate.. No differences were observed in the distribution of TF gene -603A/G genotype frequencies between the groups. Although a slightly increased incidence of +5466GA genotype was in Group 1 (17.4% vs 11.2%), it did not achieve statistical significance. The prevalence of FVL was significantly greater in Group 1 compared with Group 2 (41.3% vs 4.1%, p < 0.05). Difference in frequency of 677TT+CT (MTHFR) + 5466GG (TF) genotypes combination was found in women of two investigated Groups (p < 0.05). No differences were also in genotypes and allele frequencies of MTHFR C677T and PT G20210A between two Groups (p > 0.05).. The present study did not show significant association of TF gene -603A/G and +5466A>G polymorphisms with VTE in malignancy, however, further larger studies including different ethnic population are needed to confirm our findings.

Topics: Factor V; Female; Genotype; Humans; Male; Methylenetetrahydrofolate Reductase (NADPH2); Middle Aged; Neoplasms; Polymorphism, Genetic; Polymorphism, Restriction Fragment Length; Thromboplastin; Venous Thromboembolism

We have developed a specific technique for imaging cancer in vivo using Cy5.5-labeled factor VIIa (fVIIa), clotting-deficient FFRck-fVIIa, paclitaxel-FFRck-fVIIa, and anti-tissue factor (TF) antibody. FVIIa is the natural ligand for TF. We took advantage of the fact that vascular endothelial cells (VECs) in cancer, but not normal tissue, aberrantly express TF due to its induction by vascular endothelial growth factor (VEGF). Under physiological conditions, TF is expressed by stromal cells and outer blood vessel layers (smooth muscle and adventitia), but not by VECs. We hypothesized that labeled fVIIa or anti-TF antibodies could be used to image the tumor vasculature in vivo. To test this, Cy5.5-labeled fVIIa, FFRck-fVIIa, paclitaxel-FFRck-fVIIa, and anti-TF antibody were developed and administered to athymic nude mice carrying xenografts including glioma U87EGFRviii, pancreatic cancer ASPC-1 and Mia PaCa-2, and squamous cell carcinoma KB-V1. Cy5.5 labeled with these targeting proteins specifically localized to the tumor xenografts for at least 14 days but unconjugated Cy5.5 did not localize to any xenografts or organs. This method of imaging TF in the tumor VECs may be useful in detecting primary tumors and metastases as well as monitoring in vivo therapeutic responses.

Topics: Amino Acid Chloromethyl Ketones; Animals; Carbocyanines; Cells, Cultured; Factor VIIa; Heterografts; Humans; Mice; Neoplasms; Optical Imaging; Paclitaxel; Thromboplastin

To explore the functions of inflammatory cytokine, tissue factor (TF) and cancer procoagulant (CP) in non-tumor deep venous thrombosis (NT-DVT).. A total of 17 NT-DVT patients (5 males and 12 females) were selected for NT-DVT group while 20 voluntary (10 males and 10 females) blood donors for control group from May 2012 to March 2013. The levels of inflammatory cytokines interleukin 1β (IL-1 β), IL-18, tumor necrosis factor alpha (TNF-α), TF and CP were tested by enzyme-linked immunosorbent assay (ELISA) before and after treatment. Also the correlations of inflammatory cytokines and TF were determined.. The levels of inflammatory cytokines and TF were higher in NT-DVT than those in control group pre-treatment ((153.13 ± 2.30) vs (59.26 ± 1.57) ng/L, (364.27 ± 1.46) vs (67.46 ± 1.48) ng/L, (363.51 ± 1.85) vs (216.42 ± 1.55) µg/L, (66.90 ± 1.44) vs (14.55 ± 1.52) ng/L, all P < 0.05). And after anticoagulant therapy, the levels decreased (all P < 0.05). Also the levels of IL-1β,IL-18 and TNF-α were positively correlated with TF pre-treatment. And the correlation coefficients were 0.492 (P = 0.045), 0.652 (P = 0.005) and 0.511(P = 0.036) respectively. Compared with control group, the plasma level of CP had no obvious change before and after treatment (both P > 0.05).. A high level of inflammatory cytokines is an important risk factor for NT-DVT.

Topics: Cytokines; Enzyme-Linked Immunosorbent Assay; Female; Humans; Inflammation; Leg; Lower Extremity; Male; Neoplasms; Thromboplastin; Venous Thrombosis

Several studies highlight the role of inflammatory markers in thrombosis as well as in cancer. However, their combined role in cancer-associated deep vein thrombosis (DVT) and the molecular mechanisms, involved in its pathophysiology, needs further investigations. In the present study, C-reactive protein, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interleukin-1 (IL-1β), matrix metalloproteases-9 (MMP-9), vascular endothelial growth factor (VEGF), tissue factor (TF), fibrinogen and soluble P-selectin, were analyzed in plasma and in monocyte samples from 385 cancer patients, of whom 64 were concomitantly affected by DVT (+). All these markers were higher in cancer patients DVT+ than in those DVT-. Accordingly, significantly higher NF-kB activity was observed in cancer patients DVT+ than DVT-. Significant correlation between data obtained in plasma and monocyte samples was observed. NF-kB inhibition was associated with decreased levels of all molecules in both cancer DVT+ and DVT-. To further demonstrate the involvement of NF-kB activation by the above mentioned molecules, we treated monocyte derived from healthy donors with a pool of sera from cancer patients with and without DVT. These set of experiments further suggest the significant role played by some molecules, regulated by NF-kB, and detected in cancer patients with DVT. Our data support the notion that NF-kB may be considered as a therapeutic target for cancer patients, especially those complicated by DVT. Treatment with NF-kB inhibitors may represent a possible strategy to prevent or reduce the risk of DVT in cancer patients.

Topics: Aged; Biomarkers; C-Reactive Protein; Female; Fibrinogen; Humans; Interleukin-1beta; Interleukin-6; Male; Matrix Metalloproteinase 9; Middle Aged; Monocytes; Neoplasms; NF-kappa B; Smoking; Thromboplastin; Tumor Necrosis Factor-alpha; Vascular Endothelial Growth Factor A; Venous Thrombosis

tTF-NGR retargets the extracellular domain of tissue factor via a C-terminal peptide GNGRAHA, a ligand of the surface protein aminopeptidase N (CD13) and upon deamidation of integrin αvβ3, to tumor vasculature. tTF-NGR induces tumor vascular infarction with consecutive antitumor activity against xenografts and selectively inhibits tumor blood flow in cancer patients. Since random PEGylation resulted in favorable pharmacodynamics of tTF-NGR, we performed site-directed PEGylation of PEG units to the N-terminus of tTF-NGR to further improve the antitumor profile of the molecule. Mono-PEGylation to the N-terminus did not change the procoagulatory activity of the tTF-NGR molecule as measured by Factor X activation. Experiments to characterize pharmacokinetics in mice showed a more than 1 log step higher mean area under the curve of PEG20k-tTF-NGR over tTF-NGR. Acute (24 h) tolerability upon intravenous application for the mono-PEGylated versus non-PEGylated tTF-NGR compounds was comparable. PEG20k-tTF-NGR showed clear antitumor efficacy in vivo against human tumor xenografts when systemically applied. However, site-directed mono-PEGylation to the N-terminus does not unequivocally improve the therapeutic profile of tTF-NGR.

Topics: Animals; Cell Line, Tumor; Cloning, Molecular; Humans; Mass Spectrometry; Mice; Mice, Nude; Neoplasm Transplantation; Neoplasms; Neovascularization, Pathologic; Oligopeptides; Polyethylene Glycols; Protein Interaction Domains and Motifs; Recombinant Fusion Proteins; Thromboplastin

Cancer is often associated with an increased risk of thrombotic events which are exacerbated by treatment with chemotherapeutics such as cyclosphosphamide (CP). Evidence suggests that thrombin can stimulate tumor progression via formation of fibrin and activation of protease-activated receptors (PARs) and platelets. We examined the effect of co-treatment with CP and dabigatran etexilate, a direct inhibitor of thrombin, using the murine orthotopic 4T1 tumor model. Mice receiving co-treatment with both low dose CP and dabigatran etexilate had significantly smaller mammary tumors and fewer lung metastases than mice treated with CP or dabigratran etexilate alone. Co-treatment with dabigatran etexilate and low dose CP also significantly decreased the number of arginase(+)Gr-1(+)CD11b(+) myeloid derived suppressor cells as well as levels of TGF-β in spleens from tumor bearing mice. 4T1 tumors express procoagulant tissue factor (TF) and spontaneously release TF(+) microparticles which are potent procoagulant factors that promote thrombin generation. Treatment with dabigatran etexilate alone prevented tumor-induced increases in circulating TF(+) microparticles and also decreased the numbers of tumor-induced activated platelets by 40%. These results show that co-treatment with dabigatran etexilate and CP synergistically inhibits growth and metastasis of mammary tumors, suggesting that oral administration of the thrombin inhibitor dabigatran etexilate may be beneficial in not only preventing thrombotic events in cancer patients but also in treating malignant tumors themselves.

Topics: Animals; Antineoplastic Agents, Alkylating; Antithrombins; Cell Line, Tumor; Cell-Derived Microparticles; Cyclophosphamide; Dabigatran; Disease Models, Animal; Disease Progression; Drug Synergism; Female; Mice; Myeloid Cells; Neoplasm Metastasis; Neoplasms; Platelet Activation; Thrombin; Thromboplastin

Topics: Cell-Derived Microparticles; Female; Humans; Male; Neoplasms; Thromboplastin; Thrombosis; Venous Thromboembolism

Topics: Cell-Derived Microparticles; Female; Humans; Male; Neoplasms; Thromboplastin; Thrombosis; Venous Thromboembolism

Tumor-derived tissue factor (TF) activates coagulation in vitro and in vivo in an orthotopic model of human pancreatic cancer. Here, we further characterized tumor-derived TF in this model.. Conditioned medium (CM) of L3.6pl human pancreatic tumor cells and plasma from nude mice bearing L3.6pl tumors were ultracentrifuged, and the pellets were filtered through membranes with different pore sizes. The size distribution of particles was analyzed in CM or plasma fractions with nanoparticle tracking and dynamic light scattering. Human TF antigen and activity were measured in pellets and supernatants with ELISA and clotting or thrombin generation assays, respectively. Human alternatively spliced TF (asTF) was measured with ELISA. Human TF and thrombin-antithrombin complex (TAT) concentrations were assessed in plasma of mice injected with filtered fractions of CM.. Particles in both CM and plasma were < 0.4 μm. TF antigen and activity in the CM were mainly associated with microparticles (MP). Approximately 50% of antigen and 20% of activity were associated with particles of < 0.1 μm. Injection of < 0.1 μm particles into mice caused a 30% drop in platelet counts and an increase in TAT levels. In contrast, ~ 90% of TF antigen in tumor-bearing mice plasmas was non-sedimentable, whereas TF activity was exclusively associated with MP. Particles of < 0.1 μm and the supernatants of both CM and plasma gained TF activity after addition of exogenous phospholipids. Although asTF was found in MP-free CM supernatants, it was also present in CM and plasma pellets.. Tumor-derived particles of < 0.1 μm and non-sedimentable TF are or can become procoagulant in the presence of phospholipids, and may contribute to the procoagulant potential of circulating TF.

Topics: Animals; Blood Coagulation; Cell Line, Tumor; Enzyme-Linked Immunosorbent Assay; Humans; Mice; Mice, Nude; Neoplasms; Thromboplastin

Tissue factor (TF) is aberrantly expressed in solid cancers and is thought to contribute to disease progression through its procoagulant activity and its capacity to induce intracellular signaling in complex with factor VIIa (FVIIa). To explore the possibility of using tissue factor as a target for an antibody-drug conjugate (ADC), a panel of human tissue factor-specific antibodies (TF HuMab) was generated. Three tissue factor HuMab, that induced efficient inhibition of TF:FVIIa-dependent intracellular signaling, antibody-dependent cell-mediated cytotoxicity, and rapid target internalization, but had minimal impact on tissue factor procoagulant activity in vitro, were conjugated with the cytotoxic agents monomethyl auristatin E (MMAE) or monomethyl auristatin F (MMAF). Tissue factor-specific ADCs showed potent cytotoxicity in vitro and in vivo, which was dependent on tissue factor expression. TF-011-MMAE (HuMax-TF-ADC) was the most potent ADC, and the dominant mechanism of action in vivo was auristatin-mediated tumor cell killing. Importantly, TF-011-MMAE showed excellent antitumor activity in patient-derived xenograft (PDX) models with variable levels of tissue factor expression, derived from seven different solid cancers. Complete tumor regression was observed in all PDX models, including models that showed tissue factor expression in only 25% to 50% of the tumor cells. In conclusion, TF-011-MMAE is a promising novel antitumor agent with potent activity in xenograft models that represent the heterogeneity of human tumors, including heterogeneous target expression.

Topics: Aminobenzoates; Animals; Antibodies, Monoclonal; Antineoplastic Agents; Cells, Cultured; HCT116 Cells; HEK293 Cells; Humans; Immunoconjugates; Mice; Mice, Nude; Molecular Targeted Therapy; Neoplasms; Oligopeptides; Thromboplastin; Xenograft Model Antitumor Assays

Microparticles, found in all body fluids including peripheral blood, are important elements that regulate cellular interactions under both physiological and pathological conditions. They play an important role in blood clot formation and increased cell aggregation. However, little is known about the components of the microparticles and their mechanism of action. A method to quantify and assess the underlying mechanism of action of microparticles in pathologies is therefore desirable. We present a specific method to isolate cell-derived microparticles from malignant effusions using annexin V-coated magnetic microbeads. The microparticles can be detected by flow cytometry. Our results show that the microparticles can be isolated with >80% specificity when bound to annexin V-coated magnetic beads, which was originally developed for the detection of apoptotic cells. We also show that the isolated microparticles were still functionally active and can be used for further analysis. Thus, our method enables isolation as well as structural and functional characterisation of the microparticles which are produced in numerous patho-physiological situations. This should help gain a deeper insight into various disease situations, which in turn should pave the way for the development of novel drugs and specific therapy strategies.

Topics: Annexin A5; Body Fluids; Calcium; Cell-Derived Microparticles; Flow Cytometry; Humans; Magnetic Phenomena; Microspheres; Neoplasms; Thromboplastin

Cellular senescence, a programmed state induced by multiple deleterious triggers, is characterised by permanent cell-cycle exit and altered gene expression and cell morphology. In humans it is considered a tumor suppressor mechanism, mediating removal of damaged or mutated cells from the cell-cycle pool, and may also contribute to the ageing process. In this study, we show that senescent human umbilical vein endothelial cells lose their ability to induce tissue factor (TF), a transmembrane protein with important roles in hemostasis and cancer progression, in response to thrombin or - independently of cell-surface receptors - phorbol-12-myristate-13-acetate. This phenomenon could not be explained by senescence-related alterations in the downstream signal transduction cascade or by accelerated TF mRNA degradation. Rather, using chromatin immuno-precipitation we could show that loss of TF gene inducibility during senescence occurs following chromatin remodelling of the TF promoter resulting from hypo-acetylation of histone H3. These findings were reversible after transduction of presenescent cultures with telomerase reverse transcriptase, enabling late-passage cultures to escape senescence. These results extend the involvement of heterochromatic gene silencing in senescence beyond cell cycle-related genes and suggest a novel anti-cancer mechanism of senescence through inhibition of TF inducibility.

Topics: Acetylation; Cellular Senescence; Chromatin; Epigenesis, Genetic; Gene Expression; Gene Silencing; Hemostasis; Heterochromatin; Histones; Human Umbilical Vein Endothelial Cells; Humans; Neoplasms; Promoter Regions, Genetic; RNA, Messenger; Signal Transduction; Telomerase; Thromboplastin

Progression to an angiogenic state is a critical event in tumor development, yet few patient characteristics have been identified that can be mechanistically linked to this transition. Antiphospholipid autoantibodies (aPLs) are prevalent in many human cancers and can elicit proangiogenic expression in several cell types, but their role in tumor biology is unknown. Herein, we observed that the elevation of circulating aPLs among breast cancer patients is specifically associated with invasive-stage tumors. By using multiple in vivo models of breast cancer, we demonstrated that aPL-positive IgG from patients with autoimmune disease rapidly accelerates tumor angiogenesis and consequent tumor progression, particularly in slow-growing avascular tumors. The action of aPLs was local to the tumor site and elicited leukocytic infiltration and tumor invasion. Tumor cells treated with aPL-positive IgG expressed multiple proangiogenic genes, including vascular endothelial growth factor, tissue factor (TF), and colony-stimulating factor 1. Knockdown and neutralization studies demonstrated that the effects of aPLs on tumor angiogenesis and growth were dependent on tumor cell-derived TF. Tumor-derived TF was essential for the development of pericyte coverage of tumor microvessels and aPL-induced tumor cell expression of chemokine ligand 2, a mediator of pericyte recruitment. These findings identify antiphospholipid autoantibodies as a potential patient-specific host factor promoting the transition of indolent tumors to an angiogenic malignant state through a TF-mediated pathogenic mechanism.

Topics: Animals; Antibodies, Antiphospholipid; Breast Neoplasms; Cell Line, Tumor; Cell Proliferation; Cell Survival; Disease Progression; Endotoxins; Female; Gene Expression Regulation; Humans; Immunoglobulin G; Mice; Mice, Inbred C57BL; Mice, Nude; Microscopy, Fluorescence; Neoplasm Transplantation; Neoplasms; Neovascularization, Pathologic; Thromboplastin

A prothrombotic state is one of the hallmarks of malignancy and a major contributor to morbidity and mortality in cancer patients.Tissue factor (TF) is often overexpressed in malignancy and is a prime candidate in predicting the hypercoagulable state. Moreover, increased number of TF-exposing microparticles (MPs) in cancer patients may contribute to venous thromboembolism (VTE). We have conducted a prospective cohort study to determine whether elevated TF antigen, TF activity and TF associated to MPs (MPs-TF) are predictive of VTE and mortality in cancer patients. The studied population consisted of 252 cancer patients and 36 healthy controls. TF antigen and activity and MPs-TF were determined by ELISA and chromogenic assays. During a median follow-up of 10 months, 40 thrombotic events were recorded in 34 patients (13.5%), and 73 patients (28.9%) died. TF antigen and activity were significantly higher in patients than in controls (p<0.01) mainly in patients with advanced stages, whereas no differences were observed for TF activity of isolated MPs. We did not find a statistically significant association of TF variables with the risk of VTE. Multivariate analysis adjusting for age, sex, type of cancer and other confounding variables showed that TF activity (p<0.01) and MPs-TF activity (p<0.05) were independently associated with mortality. In conclusion, while TF variables were not associated with future VTE in cancer patients, we found a strong association of TF and MPs-TF activity with mortality, thus suggesting they might be good prognostic markers in cancer patients.

Topics: Aged; Aged, 80 and over; Case-Control Studies; Cell-Derived Microparticles; Coagulants; Enzyme-Linked Immunosorbent Assay; Female; Follow-Up Studies; Humans; Male; Middle Aged; Neoplasms; Predictive Value of Tests; Prospective Studies; Thromboplastin; Thrombosis; Time Factors; Venous Thromboembolism

Haemostatic alterations are commonly detected in human and canine cancer patients. Previous studies have described haemostatic dysfunction in canine patients with haemangiosarcomas and carcinomas, and haemostasis has been assessed in dogs with various malignant and benign neoplasias. Few studies have addressed the effect of cancer type and progression of disease on the presence of haemostatic alterations in canine patients. The objective of the present study was to evaluate haemostatic variables of coagulation and fibrinolysis in a group of canine cancer patients, and to compare haemostatic changes to the cancer type and progression of disease.. The study population consisted of 71 dogs with malignant neoplasia presented to the University Hospital for Companion Animals, Faculty of Life Sciences, University of Copenhagen, Denmark. The study was designed as a prospective observational study evaluating the haemostatic function in canine cancer patients stratified according to type of cancer disease and disease progression. The coagulation response was evaluated by thromboelastrography (TEG), platelet count, activated partial thromboplastin time (aPTT), prothombin time (PT), fibrinogen and antithrombin (AT); and fibrinolysis by d-dimer and plasminogen.. Hypercoagulability was the most common haemostatic dysfunction found. Non mammary carcinomas had increased clot strength (TEG G), aPTT and fibrinogen compared to the other groups. When stratifying the patients according to disease progression dogs with distant metastatic disease exhibited significantly increased fibrinogen, and d-dimer compared to dogs with local invasive and local non-invasive cancers.. Hypercoagulability was confirmed as the most common haemostatic abnormality in canine cancer patients and haemostatic dysfunction in canine cancer patients was found related to the cancer type and progression of disease. Increase in TEG G, aPTT and fibrinogen were observed in non-mammary carcinomas and were speculated to overall represent a proinflammatory response associated with the disease. Dogs with distant metastatic disease exhibited increased fibrinogen and d-dimer. Future studies are needed to elucidate the clinical importance of these results.

Topics: Animals; Blood Coagulation; Denmark; Disease Progression; Dog Diseases; Dogs; Female; Fibrinolysis; Hemostasis; Hemostatic Disorders; Male; Neoplasms; Prospective Studies; Recombinant Proteins; Thrombelastography; Thromboplastin

The goal of this study was to develop novel embolic nanoparticles for targeted tumor therapy with dual targeting: magnetic field-guided and peptide-directed targeting. The embolic nanoparticles SP5.2/tTF-OCMCs-SPIO-NPs were prepared by surface-modifying of superparamagnetic iron oxide nanoparticles (SPIO-NPs) with o-carboxymethylchitosans (OCMCs) and SP5.2/tTF (SP5.2: a peptide binding to VEGFR-1; tTF: truncated tissue factor) to improve their stability and to target over-expressing VEGFR-1 cells. The physicochemical characterization results showed that the OCMCs-SPIO-NPs have a spherical or ellipsoidal morphology with an average diameter of 10-20 nm. And they possess magnetism with a saturation magnetization of 66.1 emu/g, negligible coercivity and remanence at room temperature. In addition, the confocal microscopy, Prussian blue staining and FX activation analysis respectively demonstrated the peptide-directed targeting, magnetic field-guided targeted and blood coagulation activity of the SP5.2/tTF-OCMCs-SPIO-NPs. These properties separately belong to SP5.2, Fe(3)O(4) and tTF moieties of the SP5.2/tTF-OCMCs-SPIO-NPs. Thus these SP5.2/tTF-OCMCs-SPIO-NPs with double-targeting function should have a potential application in embolization therapy of tumor blood vessels.

Topics: Animals; Blood Coagulation; Cell Line, Tumor; Chitosan; Embolization, Therapeutic; Factor Xa; Human Umbilical Vein Endothelial Cells; Humans; Magnetic Fields; Magnetite Nanoparticles; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Microscopy, Confocal; Microscopy, Electron, Scanning; Nanotechnology; Neoplasms; Particle Size; Peptides; Recombinant Fusion Proteins; Spectroscopy, Fourier Transform Infrared; Thromboplastin; Vascular Endothelial Growth Factor Receptor-1; X-Ray Diffraction; Xenograft Model Antitumor Assays

Tissue factor (TF) expression by tumor cells correlates with metastasis clinically and supports metastasis in experimental settings. However, the precise pathways coupling TF to malignancy remain incompletely defined. Here, we show that clot formation by TF indirectly enhances tumor cell survival after arrest in the lung, during experimental lung metastasis, by recruiting macrophages characterized by CD11b, CD68, F4/80, and CX(3)CR1 (but not CD11c) expression. Genetic or pharmacologic inhibition of coagulation, by either induction of TF pathway inhibitor ex-pression or by treatment with hirudin, respectively, abrogated macrophage recruitment and tumor cell survival. Furthermore, impairment of macrophage function, in either Mac1-deficient mice or in CD11b-diphtheria toxin receptor mice in which CD11b-positive cells were ablated, decreased tumor cell survival without altering clot formation, demonstrating that the recruitment of functional macrophages was essential for tumor cell survival. This effect was independent of NK cells. Moreover, a similar population of macrophages was also recruited to the lung during the formation of a premetastatic niche. Anticoagulation inhibited their accumulation and prevented the enhanced metastasis associated with the formation of the niche. Our study, for the first time, links TF induced coagulation to macrophage recruitment in the metastatic process.

Topics: Animals; Blood Coagulation; Cell Movement; Cell Survival; Cells, Cultured; Humans; Macrophages; Melanoma, Experimental; Mice; Mice, Inbred C57BL; Mice, SCID; Mice, Transgenic; Monocytes; Neoplasm Metastasis; Neoplasms; Neoplastic Stem Cells; Stem Cell Niche; Thromboplastin

Thrombosis portends a poor prognosis in individuals with solid tumors. Constitutive expression of tissue factor (TF) by cancer cells is a key in triggering activation of coagulation and promoting aggressive tumor behavior. Though multiple myeloma (MM) is associated with a high frequency of thrombosis in the context of thalidomide and lenalidomide therapy, prognosis is not affected by its occurrence. We sought to determine the expression of TF in MM. F3 (TF gene) expression profiling was analyzed in 55 human MM cell lines (HMCL) and in 223 solid tumor cell lines obtained from GlaxoSmithKline (GSK) Cancer Cell Line Genomic Profiling Dataset. TF was not expressed in any of the 55 HMCLs studied, in sharp contrast to solid tumors, 90% of which showed TF expression. F3 expression was also absent in tumor samples from 239 MM patients. Immunohistochemistry for TF was negative, with either no or focal (1+) staining in 70/73 MM patients. Only three marrow biopsies were moderately (2+) positive either focally or diffusely, suggesting that in rare cases bone marrow microenvironment may support TF expression. General lack of TF expression by neoplastic plasma cells may explain why thrombosis is not predictive of poor outcome, and why aspirin prophylaxis is often effective in MM.

Topics: Blood Coagulation; Bone Marrow; Cell Line, Tumor; Humans; Immunoenzyme Techniques; Multiple Myeloma; Neoplasms; Plasma Cells; Prognosis; Thromboplastin; Thrombosis

Cancers are associated with varying degrees of an increased risk of venous thromboembotic events (VTE) occurring. This increased risk is tumour driven and associated with tumour expression of tissue factor (TF) and tumour-derived microparticles (MP). In this study, cancer cell lines from phenotypically distinct tumours were assessed for cell surface TF expression and prothrombin time (PT) taken as a measure of procoagulant potential.. Breast (T47D, MCF-7), colorectal (Colo320 and LoVo), head and neck (USCC 11b, 12, 81b and SIHN-011A) and pancreatic tumour cell lines (ASPC-1 and CFPAC-1) were assessed for TF expression by flow cytometry and relative mean fluorescence determined. Procoagulant potential of the cells was then determined by PT assay.. Cell-supported coagulation was shown to be cell number dependent, defined by a logarithmic relationship that was consistent across all cell lines. Single cell PT was determined for each cell line from the slope of a logarithmically transformed data plot. A near linear relationship was observed between TF expression and single cell clotting time where a higher expression of TF results in a proportionally faster PT (P < 0.001).. This study shows that across a range of tumour sites a consistent relationship is seen between procoagulant potential and both cell number and TF cell surface expression.

Topics: Cell Aggregation; Cell Line, Tumor; Flow Cytometry; Gene Expression Regulation; Humans; Neoplasms; Prothrombin Time; Thromboplastin

Thrombin, the final enzyme of blood coagulation, is a multifunctional serine protease also involved in the progression of cancer. Tumor cells may activate blood coagulation proteases through the expression of procoagulant activities. However, specific information about the thrombin generation potential of malignant tissues is lacking. In this study we applied a single global coagulation test, the calibrated automated thrombogram assay, to characterize the specific procoagulant phenotypes of different tumor cells.. Malignant hematologic cells (i.e. NB4, HEL, and K562) or solid tumor cells (i.e. MCF-7 breast cancer and H69 small cell lung cells) were selected for the study. The calibrated automated thrombo-gram assay was performed in normal plasma and in plasma samples selectively deficient in factor VII, XII, IX or X, in the absence or presence of a specific anti-tissue factor antibody. Furthermore, cell tissue factor levels were characterized by measuring antigen, activity and mRNA expression.. In normal plasma, NB4 induced the highest thrombin generation, followed by MCF-7, H69, HEL, and K562 cells. The anti-tissue factor antibody, as well as deficiencies of factors VII, IX and XII affected the thrombin generation potential of malignant cells to different degrees, allowing differentiation of the two different pathways of blood clotting activation - by tissue factor or contact activation. The thrombin generation capacity of NB4 and MCF-7 cells was tissue factor-dependent, as it was highly sensitive to inhibition by anti-tissue factor antibody and factor VII deficiency, while the thrombin generation capacity of H69, HEL and K562 was contact activation-dependent, as no thrombin was generated by these cells in factor XII-deficient plasma.. This study demonstrates that the calibrated automated thrombogram assay is capable of quantifying, characterizing, and comparing the thrombin generation capacity of different tumor cells. This provides a useful tool for understanding the key factors determining the global pro-coagulant profile of tumors, which is important for addressing specific targeted therapy for the prevention of thrombosis and for cancer.

Topics: Blood Coagulation Tests; Cell Line, Tumor; Factor X Deficiency; Factor XII Deficiency; Hemophilia B; Humans; Leukemia; Neoplasms; Thrombin; Thromboplastin

Tumor associated coagulopathy is a complex phenomenon that has been the subject of study for more than a century. Many mechanisms have been implicated in this process including tumor-host interactions, growth factor-, and cytokine-mediated signaling in the tumor microenvironment. Tissue factor (TF), a potent procoagulant, is considered to be critical for physiologic and pathological coagulation. The genetic and microenvironmental features of cancer appear to strongly influence the expression of TF and lead to a procoagulant state both locally within the neoplasm as well as systemically. In association with cytokines and other procoagulants, upregulated TF and its downstream effectors such as thrombin not only lead to abnormal blood clotting in cancer patients but also stimulate a wide number of oncogenic signaling mechanisms that may prove important in cancer progression. In glioblastoma multiforme (GBM), EGFR expression and PTEN loss both lead to increased TF expression and thrombosis in a manner that appears to cause hypoxia-induced tumor progression. This review consolidates aspects of aberrant coagulation in cancer, the relevance of TF and its regulation by oncogenic alterations, with specific reference to GBM.

Topics: Animals; Gene Expression Regulation, Neoplastic; Humans; Neoplasms; Signal Transduction; Thromboplastin; Thrombosis

Heparanase that was cloned from and is abundant in the placenta is implicated in cell invasion, tumor metastasis and angiogenesis. We have recently demonstrated that heparanase may also affect the hemostatic system in a non-enzymatic manner. Heparanase was shown to up-regulate tissue factor (TF) expression and interact with tissue factor pathway inhibitor (TFPI) on cell surface, leading to dissociation of TFPI from cell membrane of endothelial and tumor cells, resulting in increased cell surface coagulation activity. We have lately shown that heparanase directly enhances TF activity resulting in increased factor Xa production and activation of the coagulation system. Data indicate increased plasma levels of heparanase suggesting its possible involvement in pregnancy vascular complications. Elevation in heparanase levels and procoagulant activity was also documented in orthopedic surgery patients receiving prophylactic doses of enoxaparin. Taking into account the pro-metastatic and pro-angiogenic functions of heparanase, with over-expression in human malignancies and abundance in platelets and placenta, its involvement in the coagulation machinery is an intriguing novel platform for further research.

Topics: Blood Coagulation; Enzyme Activation; Female; Glucuronidase; Humans; Lipoproteins; Neoplasms; Pregnancy; Pregnancy Complications; Thromboplastin; Thrombosis

Cancer is a prothrombotic state, with an increased prevalence of venous thromboembolism (VTE). Microparticles (MPs) are sub-micron-sized vesicles derived from activated or apoptotic cells that may play a role in VTE, although evidence of this association is still limited.. To evaluate the hypothesis that elevated numbers of endothelial (EMPs), platelets (PMPs), and Tissue Factor-bearing MPs (TF(+)MPs) in plasma may contribute to cancer-associated thrombosis.. EMPs, PMPs and TF(+)MPs plasma levels were measured in 90 consecutive patients (cases) referred to our Department (30 with a first episode of unprovoked VTE; 30 with active cancer; 30 with a diagnosis of acute VTE associated with active cancer), and in a group of 90 healthy subjects (controls). MPs analyses were performed by flow-cytometry (Cytomics FC500).. Cases showed statistically significant higher (mean ± SD) circulating EMPs and PMPs plasma levels (920 ± 341 and 1221 ± 413 MP/μL, respectively) than controls (299 ± 102 and 495 ± 241 MP/μL; p<0.005). Moreover cancer patients (with and without VTE) showed higher (mean ± SD) TF(+)MPs (927 ± 415 MPs/μL) than controls (204 ± 112 MPs/μL; p<0.001). The subgroup of cancer patients plus VTE showed statistically significant higher TF(+)MPs plasma levels (1019 ± 656 MPs/μL) than cancer patients without VTE (755 ± 391 MPs/μL, p = 0.002). Multivariate analysis failed to show a significant association between elevated TF(+)MPs and VTE in cancer patients.. Our results suggest that MPs might be an important intermediate in the cascade of cellular injury and vascular dysfunctions underlying the process of thrombosis, particularly in cancer. Further clinical investigations are needed to confirm the precise role of MPs in predicting hypercoagulable state in patients with cancer.

Topics: Adult; Aged; Aged, 80 and over; Blood Platelets; Case-Control Studies; Cell-Derived Microparticles; Endothelial Cells; Female; Flow Cytometry; Humans; Male; Middle Aged; Neoplasms; Thromboplastin; Venous Thromboembolism

Among cancers, pancreatic cancer is known to be associated with a higher incidence of venous thromboembolism (VTE). The aim of the study was to determine the implication of circulating tissue factor (TF) in VTE related to active pancreatic cancer. One hundred and sixty-four consecutive patients who participated to the Etude des Determinants et Interactions de la Thrombose veineuse (EDITH) study between January 2005 and August 2007 for symptomatic VTE related to active pancreatic cancer (n = 8), active cancer of other location (n = 42) or classified as unprovoked (n = 114) were included. TF activity (TFa) was measured in a one-stage kinetic chromogenic method. There were no differences of median TFa levels between patients with VTE related to cancer of other type than pancreas [2.01 pmol/l range (0.05-43.92)] and patients with unprovoked VTE [1.78 pmol/l (range 0.05-63.72), P = 0.21]. Median TFa levels were higher in patients with VTE related to pancreatic cancer [12.67 pmol/l (range 0.05-112.04)] than in patients with VTE related to cancer of other type [2.01 pmol/l (range 0.05-43.92), P = 0.02]. Higher levels of circulating TFa during the course of pancreatic cancer may explain the higher incidence of VTE associated with this type of cancer.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Female; Fibrin Fibrinogen Degradation Products; Humans; Incidence; Male; Middle Aged; Neoplasm Staging; Neoplasms; Pancreatic Neoplasms; Prospective Studies; Thromboplastin; Venous Thromboembolism

Topics: Animals; Antineoplastic Agents; Breast Neoplasms; DNA; Doxorubicin; Endothelial Cells; Epirubicin; Female; Histones; Humans; Monocytes; Neoplasms; Protein C; Thrombin; Thrombomodulin; Thrombophilia; Thromboplastin; Thrombosis

Cancer patients exhibit a high rate of thromboembolism (VTE). In this study, we analyzed levels of microparticle (MP) tissue factor (TF) activity in cancer patients with or without VTE. Blood was collected from cancer patients within 24 h of objectively diagnosed VTE (n=53) and from cancer patients without VTE (n=13). MPs were isolated from platelet poor plasma by centrifugation at 20,000g for 15 min. MP TF activity was measured using a two-stage chromogenic assay. Cancer patients with VTE had a significantly higher mean MP TF activity compared with cancer patients without VTE (1.7+/-3.8 pg/mL vs 0.6+/-0.4 pg/mL, p<0.05). Further prospective studies are required to determine if levels of MP TF activity may be a useful biomarker to identify patients at increased risk for VTE.

Topics: Biomarkers; Case-Control Studies; Cell-Derived Microparticles; Centrifugation; Chromogenic Compounds; Colonic Neoplasms; Humans; Lung Neoplasms; Neoplasms; Pancreatic Neoplasms; Thromboplastin; Venous Thromboembolism

A variety of fusion proteins consisting of the extracellular domain of tissue factor (truncated tissue factor, tTF) fused to the peptides GRGDSP (abbr. RGD), GNGRAHA (abbr. NGR) or derivates of these peptides, have been synthesized. These binding motif peptides target av-integrins or aminopeptidase N (CD13), respectively, on tumor endothelial cells. After expression and deposition as inclusion bodies in Escherichia coli BL21 (DE3), the tTF-fusion proteins were refolded and purified in a multi-step chromatography process. The upscaling process of fusion protein synthesis in order to produce amounts needed for clinical studies is presented. The proteins retained their specific proteolytic ability to activate FX by FVIIa and were able to bind to endothelial cells in vitro. Western blot analysis, analytic chromatography, FX coagulation assay and in vivo experiments have been performed to test for the in vitro stability of the tTF-NGR protein after long-term incubation at 5 degrees C or 25 degrees C, respectively. In vivo xenograft studies in nude mice bearing different malignant human tumors (mammary carcinoma SKBR3, adenocarcinoma of the lung A549) revealed that intravenous or subcutaneous administration of tTF-NGR or -RGD fusion proteins, but not the tTF protein without binding motif, induced thrombosis of tumor vessels which led to significant tumor growth retardation or regression. The anti-vascular mechanism of the tTF fusion proteins was verified by the molecular imaging methods such as magnetic resonance imaging (MRI) and fluorescence reflectance imaging (FRI); MRI showed a reduction of the relative tumor blood volume (BV) and FRI the formation of fibrin in the tTF-fusion protein treated tumors.

Topics: Animals; Antineoplastic Agents; Blood Vessels; Escherichia coli; Gene Expression; Humans; Male; Mice; Mice, Nude; Neoplasms; Oligopeptides; Recombinant Fusion Proteins; Thromboplastin

Constitutive expression of tissue factor (TF) by cancer cells triggers local and systemic activation of the coagulation cascade and is a major cause of cancer-associated thrombosis. Primary breast cancer biopsies show a marked upregulation of TF and protease activated receptor (PAR) 2, as well as increased TF cytoplasmic domain phosphorylation that is correlated with cancer relapse. TF signaling involving PAR2 and integrins has multiple effects on angiogenesis and tumor progression. The non-coagulant, alternatively spliced form of TF retains an integrin-binding site and, upon deposition into the tumor stroma, stimulates angiogenesis by ligating endothelial integrins alpha(v)beta(3) and alpha(6)beta(1). On tumor cells, full-length TF is constitutively associated with laminin-binding beta(1) integrins that support TF-VIIa-PAR2 signaling leading to upregulation of pro-angiogenic and immune modulatory cytokines and growth factors. Deficiency of PAR2, but not of the thrombin receptor PAR1, delays spontaneous breast cancer development and the angiogenic switch in mice. In addition, human xenograft breast cancer growth and angiogenesis is suppressed by selective antibody inhibition of TF-VIIa-PAR2 signaling, but not by blocking TF initiated coagulation. Thus, interruption of TF signaling represents a potential anti-angiogenic strategy that does not carry an increased risk of bleeding associated with prolonged inhibition of the TF coagulation pathway.

Topics: Animals; Blood Coagulation; Breast Neoplasms; Factor VIIa; Female; Gene Expression Regulation, Neoplastic; Humans; Integrins; Mice; Neoplasms; Neovascularization, Pathologic; Receptor, PAR-2; Signal Transduction; Thromboplastin

Oncogenic transformation and aberrant cellular differentiation are regarded as key processes leading to malignancy. They produce heterogenous cellular populations including subsets of tumour initiating cells (TICs), also known as cancer stem cells (CSCs). Intracellular events involved in these changes profoundly impact the extracellular and systemic constituents of cancer progression, including those dependent on the vascular system. This includes angiogenesis, vasculogenesis, activation of the coagulation system and formation of CSC-related and premetastatic niches. Tissue factor (TF) is a unique cell-associated receptor for coagulation factor VIIa, initiator of blood coagulation, and mediator of cellular signalling, all of which influence vascular homeostasis. Our studies established a link between oncogenic events, angiogenesis and the elevated expression of TF in several types of cancer cells. The latter suggests that cancer coagulopathy and cellular events attributed to the coagulation system may have cancer-specific and genetic causes. Indeed, in human glioma cells, a transforming mutant of the epidermal growth factor receptor (EGFRvIII) triggers not only the expression of TF, but also of its ligand (factor VII) and protease activated receptors (PAR-1 and PAR-2). Consequently, tumour cells expressing EGFRvIII become hypersensitive to contact with blood borne proteases (VIIa, thrombin), which upregulate their production of angiogenic factors (VEGF and IL-8), and contribute to formation of the growth promoting microenvironment (niche). Moreover, TF overexpression accompanies features of cellular aggressiveness such as markers of CSCs (CD133), epithelial-to-mesenchymal transition (EMT) and expression of the angiogenic and prometastatic phenotype. Conversely, TF blocking antibodies inhibit tumour growth, angiogenesis, and especially tumour initiation upon injection of threshold numbers of tumourigenic cells. Likewise, TF depletion in the host compartment (e.g. in low-TF mice) perturbs tumour initiation. These observations suggest that both cancer cells and their adjacent host stroma contribute TF activity to the tumour microenvironment. We postulate that the TF pathway may play an important role in formation of the vascular niche for tumour initiating CSCs, through its procoagulant and signalling effects. Therapeutic blockade of these mechanisms could hamper tumour initiation processes, which are dependent on CSCs and participate in tumour onset, recurr

Topics: Animals; Cell Differentiation; Gene Expression Regulation, Neoplastic; Humans; Neoplasms; Neoplastic Processes; Neoplastic Stem Cells; Receptors, Proteinase-Activated; Thromboplastin

Heparanase is an endo-beta-D-glucuronidase capable of cleaving heparan sulfate (HS) side chains of heparan sulfate proteoglycans (HSPG) on cell surfaces and the extracellular matrix, activity that is strongly implicated in tumor metastasis and angiogenesis. Evidence was provided that heparanase over-expression in cancer cells results in a marked increase in tissue factor (TF) levels. Likewise, TF was induced by exogenous addition of recombinant heparanase to tumor cells and primary endothelial cells, induction that was mediated by p38 phosphorylation and correlated with enhanced procoagulant activity. TF induction was further confirmed in heparanase over-expressing transgenic mice and correlated with heparanase expression levels in leukemia patients. Heparanase was also found to be involved in the regulation of tissue factor pathway inhibitor (TFPI). A physical interaction between heparanase and TFPI was demonstrated, suggesting a mechanism by which secreted heparanase interacts with TFPI on the cell surface, leading to dissociation of TFPI from the cell membrane and increased coagulation activity, thus further supporting the local pro-thrombotic function of heparanase. Data indicate a possible involvement of heparanase in early miscarriages and point to a regulatory effect on TFPI and TFPI-2 in trophoblasts. As heparins are strong inhibitor of heparanase, in view of the effect of heparanase on TF, the role of heparins anticoagulant-activity may potentially be expanded. Taking into account the pro-metastatic and pro-angiogenic functions of heparanase, its over-expression in human malignancies and abundance in platelets, its involvement in the coagulation machinery is an intriguing novel arena for further research.

Topics: Animals; Anticoagulants; Blood Coagulation; Glucuronidase; Heparin; Humans; Lipoproteins; Neoplasms; Thromboplastin

tTF-NGR consists of the extracellular domain of the (truncated) tissue factor (tTF), a central molecule for coagulation in vivo, and the peptide GNGRAHA (NGR), a ligand of the surface protein aminopeptidase N (CD13). After deamidation of the NGR-peptide moiety, the fusion protein is also a ligand for integrin αvβ3 (CD51/CD61). Both surface proteins are upregulated on endothelial cells of tumor vessels. tTF-NGR showed binding to specific binding sites on endothelial cells in vitro as shown by flow cytometry. Subcutaneous injection of tTF-NGR into athymic mice bearing human HT1080 fibrosarcoma tumors induced tumor growth retardation and delay. Contrast enhanced ultrasound detected a decrease in tumor blood flow in vivo after application of tTF-NGR. Histological analysis of the tumors revealed vascular disruption due to blood pooling and thrombotic occlusion of tumor vessels. Furthermore, a lack of resistance was shown by re-exposure of tumor-bearing mice to tTF-NGR after regrowth following a first cycle of treatment. However, after subcutaneous (s.c.) push injection with therapeutic doses (1-5 mg/kg bw) side effects have been observed, such as skin bleeding and reduced performance. Since lethality started within the therapeutic dose range (LD10 approximately 2 mg/kg bw) no safe therapeutic window could be found. Limiting toxicity was represented by thrombo-embolic events in major organ systems as demonstrated by histology. Thus, subcutaneous injection of tTF-NGR represents an active, but toxic application procedure and compares unfavourably to intravenous infusion.

Topics: Angiogenesis Inhibitors; Animals; Blood Vessels; Cell Line, Tumor; Cells, Cultured; Drug Delivery Systems; Humans; Infarction; Injections, Subcutaneous; Mice; Mice, Nude; Neoplasms; Neovascularization, Pathologic; Oligopeptides; Recombinant Fusion Proteins; Thromboplastin; Xenograft Model Antitumor Assays

(I) To assess the feasibility of thromboplastin-plasma (TP) method for cell block, (II) to concentrate the minimal cellular material from effusions and needle-rinses by block preparation and improve visual details, (III) to compare conventional cytological smears with cell blocks for final assessment, and (IV) to assess utility of immunocytochemistry (ICC) for diagnostic accuracy. Seventy cell blocks were prepared by TP technique using surplus fluid from 38 serous effusions, and for 32 ultrasonography-guided fine-needle aspiration cytology (FNAC) material, rinses of syringes and needles were collected in normal saline after conventional cytological smears. Then, cell blocks were compared with conventional smears for adequacy, morphologic preservation, and ICC. Absolute concordance seen in 66 cases (94%) between the smears and cell blocks. Advantages with the blocks were cellular concentration in a limited field and better cellular preservation with architectural pattern. Quality of ICC was comparable to that of standard controls. Diagnostic discrepancy was seen in two cases where cell blocks were positive but smears were negative. Two cell blocks were nonrepresentative. Cell block serves as a useful adjunct to traditional cytological smears. TP method is simple, cost effective, and reproducible. It is easy when compared with agar-embedding technique. Ancillary techniques like ICC can be performed successfully.

Topics: Ascitic Fluid; Biopsy, Fine-Needle; Cell Separation; Diagnostic Errors; Histocytochemistry; Humans; Neoplasms; Pericardial Effusion; Pleural Effusion; Specimen Handling; Thromboplastin; Tissue Embedding

Both women and men with cancer are at increased risk for developing venous thromboembolism (VTE), a propensity that has been known for many years. Until recently it was assumed, however, that the association between cancer and thrombosis is an epiphenomenon - not causally related to the transforming malignant events. The pathophysiology of thrombosis in patients with cancer is complex involving multiple tumor-related and host-related factors. Several recent studies have provided strong evidence that activation of blood coagulation, perhaps most often mediated by tissue factor (TF)-rich microparticles (MPs), is linked directly to oncogene-induced malignant transformation. In addition, the development of VTE, either before or concurrent with the diagnosis of cancer, appears to predict an aggressive behavior of a tumor, and correlates with increased tumor angiogenesis and early onset of distant metastasis. The regulation of expression of TF in tumor cells is controlled at the molecular level by several oncogenes, as appears to be true for cyclooxygenase-2 (COX-2), an important regulator of platelet function and plasminogen activator inhibitor type 1 (PAI-1), an inhibitor of fibrinolysis. In addition, engagement of protease-activated receptors (PARs) by the TF-factor VIIa complex, factor Xa and/or thrombin, have now been shown to be important for tumor growth, angiogenesis and metastasis. Targeting blood clotting reactions in cancer, therefore, may provide a unique approach to cancer treatment.

Topics: Anticoagulants; Blood Coagulation; Female; Humans; Neoplasms; Thromboplastin; Thrombosis

Topics: Adult; Aged; Aged, 80 and over; Cell-Derived Microparticles; Female; Humans; Male; Middle Aged; Neoplasms; Thromboplastin; Thrombosis

Topics: Animals; Factor VIIa; Humans; Mice; Neoplasms; Protein Binding; Salivary Proteins and Peptides; Thromboplastin

The expression of tissue factor (TF) in tumors reportedly exacerbates the aggressiveness of several types of cancers. The shedding of TF-containing membrane particles is believed to influence the ability of tumors to expand and metastasize, and these microparticles may also be harmful in the onset of disseminated intravascular coagulation in specific cancers. Furthermore, the intracellular signaling that is elicited after the formation of the TF / coagulation factor VIIa complex at the cell membrane modulates the activity of adhesion molecules and mitogen-activated protein (MAP) kinases. To evaluate whether TF overexpression in tumor cells modulates its shedding and neighboring stromal cells by its catalytic or intracellular activity, TF-GFP (green fluorescent protein) and a tailless form (TFDeltaC-GFP) were stably expressed in the rat Morris hepatoma and human HT1080 fibrosarcoma cell lines. Both TF proteins were efficiently produced by tumor cells and functionally active, and their clotting activity could be blocked by the active site-inhibited factor VIIa (ASIS). TF-expressing tumorigenic cells produced a soluble factor that increased the migration of arterial smooth muscle cells in vitro. This effect was abrogated by ASIS and the PAR-1 receptor antagonist ATAP-2, showing that it is dependent on the proteolytic activity of the TF ligand factor VIIa and the thrombin-activated cell membrane receptor. We propose that TF-containing microparticles that are released in the culture medium by tumor cells influence the migratory behavior of neighboring stromal cells, thus aiding the cancer cell's tumorigenic potential.

Topics: Animals; Blood Coagulation; Blotting, Western; Catalysis; Cell Line, Tumor; Cell Membrane; Cell Migration Assays; Cell Movement; Cell Proliferation; Coculture Techniques; Green Fluorescent Proteins; Humans; Myocytes, Smooth Muscle; Neoplasms; Neovascularization, Pathologic; Rabbits; Rats; Recombinant Fusion Proteins; Thromboplastin; Transfection

Despite the strong association between malignant disease and thromboembolic disorders, the molecular and cellular basis of this relationship remains uncertain. We evaluated the hypothesis that tumor-derived tissue factor-bearing microparticles in plasma contribute to cancer-associated thrombosis.. We developed impedance-based flow cytometry to detect, quantitate, and size microparticles in platelet-poor plasma. We evaluated the number of tissue factor-bearing microparticles in a cohort of cancer patients of different histologies (N = 96) and conducted a case-control study of 30 cancer patients diagnosed with an acute venous thromboembolic event (VTE) compared with 60 cancer patients of similar age, stage, sex, and diagnosis without known VTE, as well as 22 patients with an idiopathic VTE.. Tissue factor-bearing microparticles were detected in patients with advanced malignancy, including two thirds of patients with pancreatic carcinoma. Elevated levels of tissue factor-bearing microparticles were associated VTE in cancer patients (adjusted odds ratio, 3.72; 95% confidence interval, 1.18-11.76; P = 0.01). In cancer patients without VTE, a retrospective analysis revealed a 1-year cumulative incidence of VTE of 34.8% in patients with tissue factor-bearing microparticles versus 0% in those without detectable tissue factor-bearing microparticles (Gray test P = 0.002).The median number of tissue factor-bearing microparticles in the cancer VTE cohort (7.1 x 10(4) microparticles/microL) was significantly greater than both the idiopathic VTE and cancer-no VTE groups (P = 0.002 and P = 0.03, respectively). Pancreatectomy in three patients eliminated or nearly eliminated these microparticles which coexpressed the epithelial tumor antigen, MUC-1.. We conclude that tumor-derived tissue factor-bearing microparticles are associated with VTE in cancer patients and may be central to the pathogenesis of cancer-associated thrombosis.

Topics: Aged; Biomarkers, Tumor; Case-Control Studies; Cell Culture Techniques; Cell Separation; Female; Flow Cytometry; Humans; Male; Middle Aged; Neoplasms; Risk Factors; Thromboplastin; Thrombosis; Venous Thromboembolism

Topics: Exosomes; Humans; Neoplasms; Particle Size; Thromboplastin

Topics: Animals; Humans; Neoplasms; Thromboplastin

Heparanase activity is implicated in cell invasion, tumor metastasis and angiogenesis. Recently, we have reported that heparanase stimulates tissue factor (TF) expression in endothelial and cancer cells, resulting in elevation of coagulation activity. We hypothesized that heparanase regulates other coagulation modulators, and examined the expression and localization of tissue factor pathway inhibitor (TFPI) following heparanase over-expression or exogenous addition. Primary human umbilical vein endothelial cells (HUVEC) and human tumor-derived cell lines were incubated with heparanase, or were stably transfected with heparanase gene-constructs, and TFPI expression and secretion were examined. Heparanase over-expression or exogenous addition stimulated TFPI expression by 2-3 folds. TFPI accumulation in the cell culture medium exceeded in magnitude the observed induction of TFPI gene transcription reaching 5- to 6-fold increase. Extracellular accumulation of TFPI was evident already 60 min following heparanase addition, prior to TFPI protein induction, and correlated with increased coagulation activity. This effect was found to be independent of heparanase enzymatic activity and interaction with heparan-sulfate, and correlated with reduced TFPI levels on the cell surface. Data were verified in heparanase transgenic mice tissues and plasma. Interaction between heparanase and TFPI was evident by co-immunoprecipitation. Interaction of heparanase with TFPI resulted in its displacement from the surface of the vascular endothelium and in increased pro-coagulant activity. Thus, heparanase facilitates blood coagulation on the cell surface by two independent mechanisms: dissociation of TFPI from the vascular surface shortly after local elevation of heparanase levels, and subsequent induction of TF expression.

Topics: Animals; Blood Coagulation; Cell Line, Tumor; Cell Membrane; Cells, Cultured; Endothelial Cells; Glucuronidase; Heparitin Sulfate; Humans; Lipoproteins; Mice; Mice, Transgenic; Neoplasms; Protein Binding; Recombinant Proteins; RNA, Messenger; Thromboplastin; Time Factors; Transcription, Genetic; Transfection; Up-Regulation

Cancer patients have an increased risk of thrombosis. Tissue factor (TF) antigen and TF activity associated with microparticles in plasma are elevated in patients with various types of cancer. Of these two measurements, TF activity is considered superior to TF antigen levels because the activity more closely reflects the ability of TF to initiate coagulation. Recent studies showed that platelets also express TF.. To determine the level of TF activity associated with a combined platelet and microparticle sample from cancer patients (n = 20) and healthy individuals (n = 23).. TF activity was measured using a two step chromogenic assay and soluble P-selectin was measured by ELISA in healthy controls and metastatic cancer patients.. We determined the composition of a combined platelet and microparticle sample. The sample consisted of platelets, large microparticles (30-200 nm) and membrane debris. We compared the TF activity of a combined platelet and microparticle sample from cancer patients with that from healthy individuals. We found that TF activity in a combined platelet and microparticle sample from cancer patients was higher than in samples from healthy individuals (21.5+/-12.3 pM (n = 20) versus 8.6+/-6.8 pM (n = 23), mean+/-SD, p < 0.001). Cancer patients also had a higher level of soluble P-selectin compared with controls (18.9+/-5.5 ng/mL versus 13.2+/-2.3 ng/mL, p < 0.001).. This study indicates that measurement of TF activity in a combined platelet and microparticle sample can be used as a simple assay to determine the level of circulating TF.

Topics: Adult; Aged; Aged, 80 and over; Blood Platelets; Case-Control Studies; Cell-Derived Microparticles; Female; Humans; Male; Microscopy, Electron, Transmission; Middle Aged; Neoplasms; Risk Factors; Thromboplastin; Thrombosis

Tissue factor (TF) expressed on sub-cellular membrane vesicles, so-called plasma microparticles (MPs), has recently emerged as a potential key player in intravascular coagulation activation in various disease states. In this report, we demonstrate significantly increased levels of TF-specific procoagulant activity (PCA) of plasma MPs in five patients presenting with overt disseminated intravascular coagulation (DIC) due to an underlying malignancy, including non-small-cell lung cancer (n = 1), melanoma (n = 1), prostate cancer (n = 2), and acute promyelocytic leukemia (n = 1). Clotting experiments on available tumor cell samples suggested that cancer cells were a potential source of circulating TF-positive MPs at least in three of the five patients. Furthermore, follow-up plasma samples from two surviving patients revealed that response of their malignancies to specific anti-cancer therapy was paralleled by resolution of overt DIC and a significant decline in MP-associated TF PCA. Levels of plasma TF antigen, as assessed by an enzyme-linked immunosorbent assay, were also increased at presentation albeit to a lesser extent compared to MP-associated TF PCA, likely due to insufficient solubilization of the phospholipid-incorporated full-length TF molecule by the detergent. In summary, our findings suggest that MP-associated TF PCA may play an important pathogenic role in the evolution of overt DIC in various types of malignancy.

Topics: Aged; Aged, 80 and over; Antithrombin III; Antithrombins; Disseminated Intravascular Coagulation; Factor V; Factor XIII; Female; Fibrin Fibrinogen Degradation Products; Fibrinogen; Humans; Male; Middle Aged; Neoplasms; Peptide Hydrolases; Platelet Count; Thromboplastin; Triazines

Topics: Blood Cells; Humans; Neoplasms; Particle Size; Thrombophilia; Thromboplastin

Factor VIIa (FVIIa) binding to tissue factor (TF) induces cell signaling via the protease activity of FVIIa and protease-activated receptor 2 (PAR2).. We examined how the gene-expression profile induced by FVIIa corresponds to the profiles induced by protease-activated receptor 1 (PAR1) or PAR2 agonists using MDA-MB-231 breast carcinoma cells that constitutively express TF, PAR1 and PAR2.. Out of 8500 genes, FVIIa stimulation induced differential regulation of 39 genes most of which were not previously recognized as FVIIa regulated. All genes regulated by FVIIa were similarly regulated by a PAR2 agonist peptide confirming FVIIa signaling via PAR2. An appreciable fraction of the PAR2-regulated genes was also regulated by a PAR1 agonist peptide suggesting extensive redundancy between FVIIa/PAR2 signaling and thrombin/PAR1 signaling. The FVIIa regulated genes encode cytokines, chemokines and growth factors, and the gene repertoire induced by FVIIa in MDA-MB-231 cells is consistent with a role for TF-FVIIa signaling in regulation of a wound healing type of response. Interestingly, a number of genes regulated exclusively by FVIIa/PAR2-mediated cell signaling in MDA-MB-231 cells were regulated by thrombin and a PAR1 agonist, but not by FVIIa, in the TF-expressing glioblastoma U373 cell line.

Topics: Binding Sites; Cell Line, Tumor; Factor VIIa; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Humans; Neoplasms; Oligonucleotide Array Sequence Analysis; Peptides; Receptor, PAR-1; Receptor, PAR-2; Signal Transduction; Thromboplastin; Transcription, Genetic

The efficacy of anticoagulants, low-molecular-weight heparins (LMWHs), the antiplatelet glycoprotein IIb/IIIa antagonist, or combinations on cancer-activated thrombosis was determined using thromboelastography. The LMWHs tinzaparin and enoxaparin (0.179, 1.79, 17.9 microg) were incubated in human citrated whole blood (n = 4) and then activated by calcium chloride (11 mmol/l) or Colo205 (cell count 10). Concentrations of 9.9, 17.9 and 179 microg glycoprotein IIb/IIIa antagonist, XV454, and combinations with each LMWH were carried out and activated under the same conditions. The experiment was repeated with tissue factor substituting for the Colo205 to induce platelet/fibrin clot formation. Parameters tested in the thrombelastography analysis included clotting time, rate of clot formation due to fibrin formation, clot kinetics, and clot strength related to platelet count (maximum amplitude). Tinzaparin (1.79 microg), enoxaparin (1.79 microg), and XV454 (17.9 microg) significantly reduced the angle by 64, 26 and 27%, respectively, in cancer-induced clotting. Significant reductions in the maximum amplitude occurred in tinzaparin 1.79 microg (31%), enoxaparin 1.79 microg (11%), and XV454 17.9 microg (59%). An overall antithrombotic additive effect occurred when each LMWH (1.79 microg) was combined with XV454 (17.9 microg). The results between cancer-activated and tissue factor-activated blood were similar. The study concludes that an additive effect is present between LMWHs and a glycoprotein IIb/IIIa antagonist in reducing cancer-mediated thrombosis.

Topics: Alanine; Cell Line, Tumor; Drug Therapy, Combination; Enoxaparin; Heparin, Low-Molecular-Weight; Humans; Neoplasms; Oxazoles; Platelet Glycoprotein GPIIb-IIIa Complex; Thrombelastography; Thromboplastin; Thrombosis; Tinzaparin

We have shown that the thrombin G-protein coupled receptors (GPCR) designated as protease-activated receptors (PAR-1) are expressed in primary cancer cells isolated from peritoneal and pleural malignant effusions. Here, our main goal was to evaluate several coagulation and thrombin activation effectors and markers in a series of 136 malignant effusions from cancer patients with gastrointestinal, lung and mammary carcinomas. All these patients present a highly activated coagulation system in blood and their malignant effusions, as indicated by high levels of prothrombin F1.2 fragments and D-dimers. Notably, we detected in the effusions all the coagulation factors of the tissue factor pathway inducing thrombin activation, namely factors VII, V, X and II, as well as high VEGF levels and IGF-II in mature and precursor forms. Fibrin clot formation also correlated with higher levels of free ionized calcium (iCa), suggesting that iCa and its binding protein albumin are regulatory factors for fibrinogenesis in effusions. Consequently, thrombin, VEGF and IGFII appear to converge in the promotion of survival and invasivity of the metastatic cancer cells from blood to the malignant effusions. Thus, we add new insights on the interconnections between blood coagulation disorders in cancer patients and thrombin activation in malignant effusions, including their functional interaction with PAR in metastatic cancer cells. Based on these data we propose to counteract the metastatic cascades by targeted invalidation of key effectors of the coagulation system. Therefore, potential therapeutic approaches include the application of thrombin protease inhibitors, VEGF-blocking antibodies, and drugs targeting the VEGF and thrombin signaling pathways, such as tyrosine kinase or GPCR inhibitors.

Topics: Aged; Antineoplastic Agents; Antithrombins; Ascitic Fluid; Blood Coagulation; Blood Coagulation Factors; Breast Neoplasms; Calcium; Case-Control Studies; Factor V; Factor VII; Factor X; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Gastrointestinal Neoplasms; Humans; Insulin-Like Growth Factor II; Lung Neoplasms; Male; Middle Aged; Neoplasm Invasiveness; Neoplasm Metastasis; Neoplasms; Peptide Fragments; Pericardial Effusion; Pleural Effusion, Malignant; Proteins; Prothrombin; Serum Albumin; Thrombin; Thromboplastin; Vascular Endothelial Growth Factor A

Topics: Animals; Disease Progression; Gene Expression Regulation, Neoplastic; Humans; Models, Biological; Neoplasms; Neovascularization, Pathologic; Signal Transduction; Thrombin; Thromboplastin

Clotting activation and thromboembolic manifestations are common features in patients with cancer. Tumor cells can directly activate the clotting through two procoagulants: tissue factor (TF) and cancer procoagulant (CP).. The aim was to evaluate the levels of TF and CP in patients with different tumors in order to: (1) establish an association between these markers and the tumor localization, (2) establish a correlation between the levels of procoagulants and the status of the disease, (3) evaluate if the treatment with chemotherapy induced some modifications on the levels of procoagulants, (4) evaluate the possibility of using procoagulants as predictors in the development of thrombosis.. Sixty-one patients with different types of cancer (lung, breast, digestive and genitourinary) and 20 normal controls were included. The activity of TF and CP was studied in serum samples. Statistical analysis of the data was performed by two-tailed Fisher exact test.. The TF was increased in 72.5 and 0% (p < 0.01) of cancer patients and normal controls, respectively. PC was found to be increased in 88% of the cancer patients but in healthy controls it was increased in only 15% (p < 0.01). The patients with genitourinary cancer presented the highest values of both procoagulants coinciding with a major prevalence of thrombotic events. The activity CP was found in 93% of patients with stages I and II but in patients with stages II and IV disease it was found in 85% (not significant). There were no differences in the levels of both procoagulants between the patients treated with chemotherapy and those with other treatments.. TF and CP are elevated in patients with cancer. The highest values of both procoagulants are in the genitourinary cancer group in agreement with the greater presence of thrombosis observed in this group. Clinical follow up is important in order to determine the potential value of these procoagulants and the tendency to develop thrombosis in patients with cancer.

Topics: Adolescent; Adult; Breast Neoplasms; Case-Control Studies; Cysteine Endopeptidases; Digestive System Neoplasms; Disease Progression; Female; Humans; Lung Neoplasms; Male; Middle Aged; Neoplasm Proteins; Neoplasm Staging; Neoplasms; Predictive Value of Tests; Thromboplastin; Thrombosis; Urogenital Neoplasms

Tumor development depends on multiple reciprocal interactions of tumor cells with the host cell compartment. Tumor cells initiate TF-dependent crosstalks with the tumor microenvironment by releasing procoagulant microparticles, soluble cytokines and angiogenic growth factors. Conversely, the hemostatic system in the host compartment provides multiple circuits that regulate tumor growth and sustain angiogenesis. A combination of experimental models of spontaneous and transplanted tumor development and metastasis start to delineate the role of TF in tumor progression and identified potential therapeutic approaches to target the TF pathway.

Topics: Animals; Disease Progression; Humans; Mice; Neoplasm Metastasis; Neoplasms; Neovascularization, Pathologic; Receptors, Proteinase-Activated; Signal Transduction; Thromboplastin

Oncogenic events play an important role in cancer-related coagulopathy (Trousseau syndrome), angiogenesis and disease progression. This can, in part, be attributed to the up-regulation of tissue factor (TF) and release of TF-containing microvesicles into the pericellular milieu and the circulation. In addition, certain types of host cells (stromal cells, inflammatory cells, activated endothelium) may also express TF. At present, the relative contribution of host- vs tumor-related TF to tumor progression is not known. Our recent studies have indicated that the role of TF in tumor formation is complex and context-dependent. Genetic or pharmacological disruption of TF expression/activity in cancer cells leads to tumor growth inhibition in immunodeficient mice. This occurred even in the case of xenotransplants of human cancer cells, in which TF overexpression is driven by potent oncogenes (K-ras or EGFR). Interestingly, the expression of TF in vivo is not uniform and appears to be influenced by many factors, including the level of oncogenic transformation, tumor microenvironment, adhesion and the coexpression of markers of cancer stem cells (CSCs). Thus, minimally transformed, but tumorigenic embryonic stem (ES) cells were able to form malignant and angiogenic outgrowths in the absence of TF. However, these tumors were growth inhibited in hosts (mice) with dramatically reduced TF expression (low-TF mice). Depletion of host TF also resulted in changes affecting vascular patterning of some, but not all types of tumors. These observations suggest that TF may play different roles growth and angiogenesis of different tumors. Moreover, both tumor cell and host cell compartments may, in some circumstances, contribute to the functional TF pool. We postulate that activation of the coagulation system and TF signaling, may deliver growth-promoting stimuli (e.g. fibrin, thrombin, platelets) to dormant cancer stem cells (CSCs). Functionally, these influences may be tantamount to formation of a provisional (TF-dependent) cancer stem cell niche. As such these changes may contribute to the involvement of CSCs in tumor growth, angiogenesis and metastasis.

Topics: Animals; Blood Coagulation; Disease Progression; Humans; Mice; Neoplasms; Neoplastic Stem Cells; Neovascularization, Pathologic; Oncogenes; Signal Transduction; Thromboplastin

Tissue factor (TF) initiates blood coagulation, but its expression in the vascular space requires a finite period of time. We hypothesized that targeting exogenous tissue factor to sites of vascular injury could lead to accelerated hemostasis. Since phosphatidylserine (PS) is exposed on activated cells at sites of vascular injury, we cloned the cDNA for a chimeric protein consisting of the extracellular domain of TF (called soluble TF or sTF) and annexin V, a human PS-binding protein. Both the sTF and annexin V domains had ligand-binding activities consistent with their native counterparts, and the chimera accelerated factor X activation by factor VIIa. The chimera exhibited biphasic effects upon blood coagulation. At low concentrations it accelerated blood coagulation, while at higher concentrations it acted as an anticoagulant. The chimera accelerated coagulation in the presence of either unfractionated or low-molecular-weight heparins more potently than factor VIIa and shortened the bleeding time of mice treated with enoxaparin. The sTF-annexin V chimera is a targeted procoagulant protein that may be useful in accelerating thrombin generation where PS is exposed to the vasculature, such as may occur at sites of vascular injury or within the vasculature of tumors.

Topics: Animals; Annexin A5; Anticoagulants; Blood Coagulation; Blood Vessels; Coagulants; Dose-Response Relationship, Drug; Factor VIIIa; Factor X; Hemorrhage; Heparin, Low-Molecular-Weight; Humans; Mice; Neoplasms; Neovascularization, Pathologic; Phosphatidylserines; Protein Structure, Tertiary; Recombinant Fusion Proteins; Thromboplastin

Tissue factor (TF) is a transmembrane glycoprotein that serves as the prime initiator of blood coagulation and plays a critical role in thrombosis and hemostasis. In addition, a variety of tumor cells overexpress cell-surface TF, which appears to be important for tumor angiogenesis and metastasis. To elucidate the mechanism involved in the upregulation of TF in human tumor cells, a comprehensive analysis of TF mRNA from various normal and tumor cells was performed. The results of these studies indicate that, in addition to possessing a normal full-length TF transcript and minor levels of an alternatively spliced transcript known as alternatively-spliced tissue factor (asTF), human tumor cells express additional full-length TF transcripts that are also generated by alternative splicing. Reverse transcriptase-polymerase chain reaction (RT-PCR) and 5'-rapid amplification of cDNA ends- (5'-RACE) based analyses of cytoplasmic RNA from normal and tumor cells revealed that there is alternative splicing of the first intron between exon I and exon II resulting in 2 additional TF transcripts. One of the transcripts has an extended exon I with inclusion of most of the first TF intron (955 bp), while the second transcript is formed by the insertion of a 495 bp sequence, referred to as exon IA, derived from an internal sequence of the first intron. The full length TF transcript with alternatively spliced novel exon IA, referred to as alternative exon 1A-tissue factor (TF-A), represented approximately 1% of the total TF transcripts in normal cells, but constituted 7-10% of the total TF transcript in tumor cells. Quantitative real-time RT-PCR analysis indicated that cultured human tumor cells contain 10-25-fold more copy numbers of TF-A in comparison to normal, untransformed cells. We propose that high-level expression of the novel TF-A transcript, preferentially in tumor cells, may have utility in the diagnosis and staging of a variety of solid tumors.

Topics: Adenocarcinoma; Alternative Splicing; Base Sequence; Carcinoma, Hepatocellular; Carcinoma, Transitional Cell; Cytoplasm; Exons; Humans; Introns; Leukemia, Promyelocytic, Acute; Liver Neoplasms; Molecular Sequence Data; Neoplasm Staging; Neoplasms; Pancreatic Neoplasms; Reverse Transcriptase Polymerase Chain Reaction; RNA; RNA, Messenger; Thromboplastin; Tumor Cells, Cultured; Up-Regulation

Topics: Animals; Atherosclerosis; Humans; Neoplasms; Sepsis; Thromboplastin; Wounds and Injuries

Blood coagulation factor VII (fVII) is physiologically synthesized in the liver and released into the blood. Binding of fVII to tissue factor (TF) at sites of vascular injury triggers coagulation and hemostasis. TF/fVIIa complex formation on the surface of cancer cells plays important roles in cancer biology. Although fVII is synthesized by hepatocellular carcinoma, it remained unclear how TF/fVIIa complex formation and promigratory signaling can occur for most other cancers in extravascular locations. Here, we show by reverse transcription-PCR analysis that nonhepatic cancer cell lines constitutively express fVII mRNA and that endogenously synthesized fVIIa triggers coagulation activation on these cells. fVIIa expression in cancer cells is inducible under hypoxic conditions and hypoxia-inducible factor-2 alpha bound the promoter region of the FVII gene in chromatin immunoprecipitation analyses. Constitutive fVII expression in an ovarian cancer cell line enhanced both migration and invasion. Enhanced motility was blocked by anti-TF antibodies, factor Xa inhibition, and anti-protease-activated receptor-1 antibody treatment, confirming that TF/fVIIa stimulated migration by triggering cell signaling. This study shows that ectopic synthesis of fVII by cancer cells is sufficient to support proinvasive factor Xa-mediated protease-activated receptor-1 signaling and that this pathway is inducible under hypoxia.

Topics: Basic Helix-Loop-Helix Transcription Factors; Blood Coagulation; Carbon-Carbon Ligases; Cell Hypoxia; Cell Line, Tumor; Cell Movement; Factor VII; Factor Xa; Female; Humans; Neoplasm Invasiveness; Neoplasm Proteins; Neoplasms; Ovarian Neoplasms; Receptor, PAR-1; Recombinant Fusion Proteins; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; RNA, Neoplasm; Signal Transduction; Thromboplastin; Transfection

Therapeutic strategies that target and disrupt the already-formed vessel networks of growing tumors are actively pursued. The goal of these approaches is to induce a rapid shutdown of the vascular function of the tumor so that blood flow is arrested and tumor cell death occurs. Here we show that the mammalian target of rapamycin (mTOR) inhibitor rapamycin, when administered to tumor-bearing mice, selectively induced extensive local microthrombosis of the tumor microvasculature. Importantly, rapamycin administration had no detectable effect on the peritumoral or normal tissue. Intravital microscopy analysis of tumors implanted into skinfold chambers revealed that rapamycin led to a specific shutdown of initially patent tumor vessels. In human umbilical vein endothelial cells vascular endothelial growth factor (VEGF)-induced tissue factor expression was strongly enhanced by rapamycin. We further show by Western blot analysis that rapamycin interferes with a negative feedback mechanism controlling this pathologic VEGF-mediated tissue factor expression. This thrombogenic alteration of the endothelial cells was confirmed in a one-step coagulation assay. The circumstance that VEGF is up-regulated in most tumors may explain the remarkable selectivity of tumor vessel thrombosis under rapamycin therapy. Taken together, these data suggest that rapamycin, besides its known antiangiogenic properties, has a strong tumor-specific, antivascular effect in tumors.

Topics: Angiogenesis Inhibitors; Animals; Endothelium, Vascular; Feedback, Physiological; Humans; Mice; Microcirculation; Microscopy, Video; Neoplasm Transplantation; Neoplasms; Sirolimus; Thromboplastin; Thrombosis; Vascular Endothelial Growth Factor A

The effects of combination anti-angiogenesis therapy (marimastat, captopril and fragmin) on plasma levels of coagulation initiator tissue factor (TF), platelet marker soluble P-selectin and angiogenic vascular endothelial growth factor (VEGF) were tested in 25 patients with advanced cancer. They had higher soluble P-selectin (P<0.001) and TF (P<0.001), but not VEGF (P=0.066) than 25 age and sex-matched controls. VEGF and TF correlated significantly (r=0.8, P<0.001) in cancer patients. Soluble P-selectin, TF and VEGF did not change at 4- and 8-weeks whilst on treatment. We provide further evidence linking coagulation and angiogenesis but combination anti-angiogenesis therapy does not influence plasma soluble P-selectin, TF or VEGF.

Topics: Adult; Aged; Angiogenesis Inhibitors; Anticoagulants; Captopril; Dalteparin; Female; Humans; Hydroxamic Acids; Male; Middle Aged; Neoplasms; Neovascularization, Pathologic; P-Selectin; Platelet Activation; Thromboplastin; Vascular Endothelial Growth Factor A

Tissue factor (TF) mRNA levels in leukocyte and TF antigen in plasma were examined in patients with deep vein thrombosis (DVT). Although TF mRNA levels in leukocytes were higher in patients with DVT than in healthy volunteers, they were lower in patients with DVT than in those with solid cancer and those with disseminated intravascular coagulation (DIC). On the other hand, the plasma levels of TF antigens were markedly high in patients with DVT/pulmonary embolism (PE). Analysis of the role of underlying disease of DVT showed no significant difference in TF mRNA levels and TF antigens among patients with solid cancer, post-surgical, other diseases and those free of underlying diseases. In patients with VTE, plasma levels of D-dimer, soluble fibrin, GE-XDP and plasminogen activator inhibitor-1 did not correlate with TF mRNA or TF antigen. In analysis of 18 patients with PE with and without DVT, TF mRNA levels in leukocytes correlated with the plasma levels of D-dimer. These findings suggest that TF in leukocytes is more likely to be involved in the development of thrombosis in PE than DVT.

Topics: Adult; Aged; Case-Control Studies; Disseminated Intravascular Coagulation; Female; Fibrin Fibrinogen Degradation Products; Humans; Leukocytes; Male; Middle Aged; Neoplasms; Pulmonary Embolism; RNA, Messenger; Thromboplastin; Up-Regulation; Venous Thrombosis

During development, tissue injury, and cancer, epithelial cells engage in communication with the vascular system by using several molecular mediators acting directly or through changes in the haemostatic system.The latter category is epitomised by the procoagulant cellular receptor known as tissue factor (TF). Here, we show that when cellular architecture is altered by a shift in culture conditions from monolayer to three-dimensional multicellular spheroids, expression of multiple angiogenesis effectors (VEGF, TSP-1, TSP-2, Ang-1, and TF) is profoundly altered. In particular, TF is dramatically upregulated in a transformed murine breast epithelial cell line (EMT6) under these conditions. This appears to be linked to a particular change in cell shape and cytoskeletal (actin) reorganisation, as treatment of these cells with cytochalasin D (Cyt D), but not with latrunculin B, recapitulates and potentiates TF upregulation. Collectively, these results suggest that the ability of epithelial cells to interact with the vascular system via expression of the TF gene (and other effectors) is under the control of complex alterations in cellular architecture.

Topics: Actins; Animals; Cell Line, Tumor; Cell Proliferation; Cell Shape; Cytochalasin D; Cytoskeleton; Gene Expression Regulation, Neoplastic; Humans; Mice; Neoplasms; Neovascularization, Pathologic; Thromboplastin; Up-Regulation

We compared the levels of tissue factor (TF) mRNA in leukocytes with plasma TF antigens of patients in hypercoagulable state caused by various diseases. Flow cytometric analysis showed absence of TF antigen expression on neutrophils and monocytes in healthy subjects but strong expression in both cell types of patients with infections.TF mRNA levels in leukocytes were low in healthy subjects but they were significantly elevated in patients with underlying diseases of disseminated intravascular coagulation (DIC), especially in acute myeloid leukaemia (AML) and infections.TF mRNA levels in leukocytes were significantly high in patients with all diseases except those with thrombosis, and plasma TF antigen levels were significantly high in all diseases. TF mRNA in leukocytes and plasma TF antigen levels were significantly high in patients with overt-DIC, and TF mRNA/antigen ratio was significantly high in patients with overt-DIC. In patients with solid cancers, TF mRNA and TF mRNA/antigen ratio were significantly higher in patients with metastases than those without. TF mRNA levels in leukocytes and plasma levels of TF antigen did not correlate in normal subjects and all patients, but they tended to be correlated in patients with AML, infections or overt-DIC. Our analysis suggests that TF expression in leukocytes plays an important role in various diseases but the expression level does not always correlate with plasma levels of TF antigen.

Topics: Adult; Aged; Base Sequence; Blood Coagulation Disorders; Disseminated Intravascular Coagulation; DNA, Complementary; Female; Humans; Infections; Leukocytes; Male; Middle Aged; Monocytes; Neoplasms; Neutrophils; RNA, Messenger; Thromboplastin

Numbers of circulating endothelial cells (CECs) are increased in cancer patients with progressive disease. Also, cancer patients have an increased risk for thrombotic events, being negatively associated with prognosis. Tissue factor (TF), the physiological initiator of coagulation, is present on the surface of many extravascular cells. In 34 samples from cancer patients and in seven from volunteers, CECs were quantified (with endothelium-specific anti-CD146 beads), and TF-activity assessed with a chromogenic assay. All samples displayed very limited TF-activity (patients: 1.6+/-3.1 microU; volunteers: 0.94+/-1.7 microU FXa/100 CECs, P = 0.30 by Mann-Whitney test). After in vitro TNFalpha-stimulation, CECs from both cancer patients and volunteers showed substantially increased TF-activity (endogenous activity: 17.3+/-6.4 microU; after TNFalpha-stimulation: 73.8+/-34.3 microU FXa; P = 0.028, Wilcoxon signed ranks test), reflecting the potential of CECs to generate biologically active TF. As the chromogenic assay determines a mean cellular TF-activity, we also analyzed immunohistochemical TF-antigen expression on CEC subsets. TF-antigen expression was undetectable. CECs isolated from cancer patients do not express TF. CECs can generate functional TF after stimulation and may therefore play a role in (intratumoral) coagulation induction and tumor angiogenesis.

Topics: Biomarkers, Tumor; Disease Progression; Endothelial Cells; Female; Humans; Immunohistochemistry; Male; Neoplasms; Neovascularization, Pathologic; Prognosis; Risk Factors; Thromboplastin; Thrombosis; Tumor Necrosis Factor-alpha

Topics: Alternative Splicing; Cell Line, Tumor; Humans; Neoplasm Proteins; Neoplasms; Particle Size; Protein Isoforms; Thromboplastin

We measured the plasma level of fibrinogen in 560 patients with disseminated intravascular coagulation (DIC) and evaluated its relationship with outcome and with other hemostatic markers. Forty-seven percent of patients had >200 mg/dL of plasma fibrinogen and 24% had <100 mg/dl of plasma fibrinogen, suggesting that plasma fibrinogen level is not a sensitive marker for DIC. In our analysis of outcome and plasma fibrinogen levels, the rate of death was high in leukemia/lymphoma patients with high fibrinogen concentration, but no significant difference in outcome was observed in relation to plasma fibrinogen concentration in non-leukemia/lymphoma patients with DIC. Among patients with leukemia/lymphoma, the frequency of organ failure was markedly high in patients with high plasma levels of fibrinogen. Among patients without leukemia/lymphoma, the frequency of organ failure increased concomitantly with the increase in plasma fibrinogen levels. The international normalized ratio was significantly increased in leukemia/lymphoma patients with low fibrinogen. FDP levels were slightly increased in patients with low fibrinogen. Platelet count was significantly low in patients without leukemia/lymphoma with high fibrinogen. DIC score increased concomitantly with the reduction in plasma fibrinogen levels. Plasma levels of thrombomodulin and tissue factor were significantly high in patients with high fibrinogen levels. Plasma levels of antiplasmin and plasminogen were significantly decreased in patients with low fibrinogen. Plasma levels of plasmin plasmin-inhibitor complex and tissue type plasminogen activator/plasminogen activator inhibitor-1 complex (PAI-I) were significantly higher in patients with low fibrinogen than in those with high fibrinogen. Plasma levels of PAI-I and IL-6 were significantly higher in patients with high fibrinogen than in those with low fibrinogen. Patients with high fibrinogen levels showed less activation of secondary fibrinolysis, which might explain the occurrence of organ failure and poor outcome.

Topics: Adult; Aged; alpha-2-Antiplasmin; Antifibrinolytic Agents; Antithrombin III; Biomarkers; Disseminated Intravascular Coagulation; Female; Fibrin Fibrinogen Degradation Products; Fibrinogen; Fibrinolysin; Fibrinolysis; Hematologic Neoplasms; Hemorrhage; Humans; Infections; Interleukin-1; Interleukin-6; International Normalized Ratio; Male; Middle Aged; Multiple Organ Failure; Neoplasms; Peptide Hydrolases; Plasminogen; Plasminogen Activator Inhibitor 1; Platelet Count; Prognosis; Thrombomodulin; Thromboplastin; Thrombosis; Tissue Plasminogen Activator

Topics: Blood Coagulation Factors; Hemostasis; Humans; Neoplasm Metastasis; Neoplasms; Thromboplastin

Topics: Animals; Endothelium, Vascular; Humans; Neoplasms; Receptor, PAR-1; Receptor, PAR-2; Signal Transduction; Thromboplastin

Topics: Disseminated Intravascular Coagulation; Drug Delivery Systems; Humans; Lipoproteins; Neoplasms; Protein C; Thromboplastin

To evaluate variations in the plasma tissue factor (TF) and urokinase type plasminogen activator (u-PA) system and their relationship with clinical cancer type, pathological classification and metastatic status in cancer patients.. Plasma levels of TF and its inhibitor (TFPI), as well as u-PA and its receptor (u-PAR) were measured using ELISA in 76 patients with malignant tumors and 24 patients with benign tumors.. Plasma levels of TF and u-PAR in the malignant tumor group were significantly higher than those of the benign tumor group and the normal control. U-PA and u-PAR increased significantly in patients with esophageal and gastric cancer. However, most of these parameters except TFPI did not vary according to pathological classification. A significant elevation was evident in patients with local infiltration, lymph node involvement and distal metastasis, while u-PAR only increased in the latter two categories.. Both the TF and u-PA systems are activated in cancer patients. U-PA and its receptor might prove to be a clinically useful marker for disease progression.

Topics: Adult; Aged; Aged, 80 and over; Female; Humans; Lipoproteins; Male; Middle Aged; Neoplasm Metastasis; Neoplasms; Receptors, Cell Surface; Receptors, Urokinase Plasminogen Activator; Thromboplastin; Urokinase-Type Plasminogen Activator

High cholesterol is a well-established risk factor of myocardial infarction (MI). Since monocytes play a pivotal role in the development of atherosclerosis, one might anticipate that their functional properties are very important in relation to MI. In the present study, we have explored how the lipopolysaccharide (LPS)-induced reactivity of monocytes in whole blood in vitro relates to the serum lipid profile of healthy subjects with a history of MI or cancer in their close family. Twenty of the 54 subjects (of the total 266 test subjects) in the MI families had moderately high cholesterol (7.1-10.2 mmol/l), whereas 34 had normal cholesterol. Nineteen of the normocholesterol individuals had hyperactive monocytes (high responders), whereas 15 had monocytes responding normally. Two of the 20 subjects in the high cholesterol group had hyperactive monocytes. LPS-induced tissue factor, tumour necrosis factor-alpha and interleukin-6 were on the average three to four times higher in the normocholesterol group compared with the moderately hypercholesterol group, and hence no positive correlation was found between hyperactive monocytes and cholesterol. The 42 subjects in the families with cancer had normal cholesterol, and two of these subjects had very high LPS-induced tissue factor, tumour necrosis factor-alpha and interleukin-6, whereas eight of the 170 subjects without MI or cancer in their family were high responders. This further substantiates the notion that moderately high cholesterol is not associated with enhanced monocyte activation in whole blood. Hyperactive peripheral blood monocytes are suggested to be associated with a significant risk factor in developing coronary heart disease.

Topics: Adolescent; Adult; Aged; Cholesterol; Coronary Disease; Family Health; Female; Fibrinolysis; Genetic Predisposition to Disease; Humans; Hypercholesterolemia; Infections; Interleukin-6; Lipopolysaccharides; Male; Middle Aged; Monocytes; Myocardial Infarction; Neoplasms; Plasminogen Activator Inhibitor 1; Risk Factors; Thromboplastin; Tissue Plasminogen Activator; Triglycerides; Tumor Necrosis Factor-alpha

The association between cancer and thromboembolic disease is well known. This relationship is complex and in many, perhaps most, malignant diseases acts through multiple pathways. Increased tissue factor expression by endothelial cells, monocytes or macrophages has been implicated as one of these pathways. As well as being found in the circulating blood, tissue factor is also found in urine in a lipid-associated form. Although urinary tissue factor might be independent from that found in the circulation, its levels may reflect the status of peripheral blood monocyte activation. Thus, measurements of monocyte and/or urinary tissue factor may be of clinical significance, particularly in cancer, where levels could be valuable for diagnosis and monitoring progression.

Topics: Humans; Neoplasms; ROC Curve; Thromboplastin

Vascular endothelial growth factor (VEGF) is an angiogenic hormone that increases the growth of many malignant tumors. Tissue factor (TF), the initiator of blood coagulation, is implicated in VEGF regulation. We recently reported that hemoglobin (Hb) upregulates TF on malignant cells. Therefore, to explore the role of Hb in angiogenesis, we examined its effect on VEGF production in A375 melanoma and J82 bladder carcinoma (TF+) and KG1 myeloid leukemia (TF-) cells. Hb (0.50 mg/ml) induced VEGF expression and secretion in TF+ malignant cells. VEGF secretion was inhibited by cycloheximide (85%) and the specific inhibitors of protein tyrosine kinase, genistein (71+/-0.74 and 55+/-4.90%) and mitogen-activated protein (MAP)-kinase, PD098059 (82+/-2.0 and 59+/-6.7%) in A375 and J82 cells respectively. In contrast, Hb (2.0 mg/ml) did not increase VEGF in KG1 cells. Hb-induced VEGF was purified from the culture medium of J82 cells using immunoaffinity chromatography and two isoforms (46 and 30 kd) identified. We conclude that Hb-induced synthesis of VEGF in TF-bearing malignant cells is mediated by protein tyrosine kinase and by MAP-kinase pathways.

Topics: Endothelial Growth Factors; Enzyme Inhibitors; Gene Expression Regulation; Hemoglobins; Humans; Intercellular Signaling Peptides and Proteins; Lymphokines; Mitogen-Activated Protein Kinases; Neoplasms; Protein Isoforms; Protein-Tyrosine Kinases; Signal Transduction; Thromboplastin; Tumor Cells, Cultured; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors

Clotting activation and thromboembolic manifestations are common features in patients with cancer. The two-way interaction between tumor cells and host cells is of crucial importance in this context. In the present study we investigated the effect of tumor cell-endothelial cell co-culture on the expression of procoagulant activity in the mixed cell populations.. Human tumor cell lines (HL60 promyelocytic leukemia and HeLa uterine cervical cancer) and human umbilical vein endothelial cells (HUVEC) were cultured in vitro according to standard procedures. Procoagulant activity was studied in a coagulometer and was found to be tissue factor-like. A calibration curve was obtained with decreasing concentrations of rabbit brain thromboplastin (RBT) and the procoagulant activity of both tumor cells and HUVEC was expressed as RBT U/10(5) cells.. Before incubation procoagulant activity (means S.E.) was found to be 0.18 +/- 0.04 U in HUVEC, 9.8 +/- 1.9 U in HL60 cells, 11.9 +/- 2.2 U in HeLa cells, 7.2 +/- 1.4 U in a mixed HL60 cell-HUVEC population (ratio 2:1) and 8.5 +/- 2.0 in a mixed HeLa cell-HUVEC population (ratio 2:1). Incubation at 37 degrees C for up to 4 hours of tumor cells or HUVEC alone did not produce any change in procoagulant activity. In contrast, co-incubation of tumor cells with HUVEC for 4 hours was followed by a significant increase in procoagulant activity of the mixed cell populations. Addition of supernatants from tumor cells, HUVEC or tumor cell-HUVEC co-cultures to HUVEC or tumor cells showed that the tissue factor-like procoagulant activity generated during coincubation was localized on HUVEC.. Our results show that the close interaction of tumor cells with endothelial cells may induce surface expression of tissue factor in the latter. This effect could represent an additional mechanism of clotting activation in patients with cancer.

Topics: Cell Communication; Coculture Techniques; Culture Media, Conditioned; Endothelium, Vascular; Hemostasis; Humans; Neoplasms; Thromboplastin; Tumor Cells, Cultured; Umbilical Cord

Topics: Adenoma; Biomarkers, Tumor; Humans; Intestinal Neoplasms; Intestine, Large; Male; Neoplasms; Prognosis; Prostatic Neoplasms; Thromboplastin

Apoptosis is involved in many biological processes, especially during chemotherapy in cancer patients. Chemotherapy is also associated with an increased risk of thrombosis. The relationship between thrombogenicity and apoptosis was studied in various human tumour cell lines and non-tumour cell lines. Apoptosis was induced by the chemotherapeutic agent camptothecin and by Fas ligand, then quantified by staining with fluorescein isothiocyanate-conjugated annexin V and propidium iodide. A significant correlation between thrombin generation and degree of apoptosis was observed (P < 0.0005). Addition of anti-tissue factor antibody in excess or of tissue factor pathway inhibitor partially inhibited thrombin generation, suggesting that tissue factor activation was responsible for this process. A statistical correlation between tissue factor activity and degree of apoptosis was also found (P < 0.005). Both thrombin generation and tissue factor activity were blocked by the addition of annexin V, which binds and inhibits phosphatidylserine. This indicates that the exteriorization and exposure of phosphatidylserine on the cell surface membrane during apoptosis were essential for both thrombin generation and tissue factor activation.

Topics: Annexin A5; Antineoplastic Agents, Phytogenic; Apoptosis; Camptothecin; Dose-Response Relationship, Drug; Enzyme Inhibitors; Humans; Neoplasms; Phosphatidylserines; Thrombin; Thromboplastin; Tumor Cells, Cultured

Topics: Animals; Blood Coagulation; Endothelial Growth Factors; Gene Expression; Humans; Lymphokines; Mice; Mice, SCID; Models, Biological; Neoplasms; Neovascularization, Pathologic; Thromboplastin; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors

Thrombin generation and fibrin formation are constantly determined in patients with malignancy, who are at increased risk of thromboembolic complications. Most importantly, fibrin formation is also involved in the processes of tumor spread and metastasis. Activation of blood coagulation in cancer is a complex phenomenon, involving many different pathways of the hemostatic system and numerous interactions of the tumor cell with other blood cells, including platelet, monocyte and endothelial cell. Tumor cells possess the capacity to interact with all parts of the hemostatic system. They can directly activate the coagulation cascade by producing their own procoagulant factors or they can stimulate the prothrombotic properties of other blood cell components. All of the mechanisms are not entirely understood, however research studies in the last ten years have greatly improved our knowledge of tumor-promoted pro-thrombotic functions.

Topics: Blood Coagulation; Blood Coagulation Factors; Cell Communication; Cysteine Endopeptidases; Endothelial Growth Factors; Fibrinolysin; Humans; Lymphokines; Neoplasm Proteins; Neoplasms; Prothrombin; Thromboplastin; Tumor Necrosis Factor-alpha; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors

Topics: Animals; Antibodies, Monoclonal; Antineoplastic Agents; Drug Delivery Systems; Fibronectins; Mice; Neoplasms; Recombinant Fusion Proteins; Thromboplastin

Topics: Annexin A2; Disseminated Intravascular Coagulation; Humans; Leukemia, Promyelocytic, Acute; Neoplasms; Thromboplastin

TF expression is a hallmark of cancer progression. The procoagulant functions of TF that lead to thrombin generation are critically important to support metastasis, in part through the generation of fibrin that assures prolonged arrest of tumor cells in target organs. In addition, the coagulation initiation complex, i.e. TF-VIIa-Xa, generates autocrine cell signaling though protease activated receptors. A cooperation of the TF cytoplasmic domain with protease signaling may explain the diverse contributions of TF to metastasis and angiogenesis.

Topics: Blood Coagulation; Cysteine Endopeptidases; Factor X; Humans; Neoplasm Metastasis; Neoplasm Proteins; Neoplasms; Receptor, PAR-1; Receptor, PAR-2; Receptors, Thrombin; Thromboplastin; Up-Regulation

Solid tumours growing beyond a size of 1-2 mm in diameter induce supporting connective tissue structures, the tumour stroma, comprising activated fibroblasts and newly formed blood vessels, embedded in an extracellular matrix. The selective destruction of this tissue or the inhibition of its function (e.g. tumour neoangiogenesis) may result in the destruction of tumour nodules, thus providing novel opportunities for tumour therapy. Our approach aims at an antibody-mediated induction of coagulation in tumour nodules to cut off their blood supply. As a target structure the fibroblast activation protein (FAP) is used, which is specifically and abundantly expressed on the activated fibroblasts of the tumour stroma. We constructed a fusion protein comprising a single-chain module of a FAP-specific humanized antibody [single-chain fragment variable (scFv) OS4] and the extracellular domain of human tissue factor. The fusion protein, designated TFOS4, was produced in the Proteus mirabilis protoplast expression system with a yield of 15 microg/ml. Biochemical characterization of TFOS4 revealed high-affinity binding to cellular FAP. Further, TFOS4 bound to factor VIIa and also exerted allosteric activation of factor VIIa. A complex of TFOS4 and factor VIIa bound to FAP-expressing cells efficiently generated activated factor X. Finally, cell-bound TFOS4 selectively induced plasma coagulation, implying its activity under physiological conditions, notably with relevant concentrations of coagulation factors and their natural inhibitors. These findings suggest that TFOS4 has the potential to increase the procoagulant state in a cell-type-specific fashion. No systemic coagulation or side effects were observed when TFOS4 was injected intravenously into normal mice, indicating the biosafety and specificity of the recombinant protein.

Topics: Antibodies; Antigen-Antibody Reactions; Base Sequence; DNA Primers; Neoplasms; Thromboplastin

Monocyte tissue factor expression is supposed to play an important role in the hypercoagulability of blood in cancer patients. The relation between coagulation parameters and the expression of monocyte membrane proteins involved in hemostasis or monocyte activation was studied in 21 patients with a disseminated malignancy and 21 age- and sex-matched healthy controls. In the cancer patient group no increase of monocyte tissue factor expression was found (8. 4% vs. 7.8%; P = 0.83), but a significant increase of monocyte-bound activated protein C (APC) (28.8% vs. 13.4%; P = 0.009) and monocyte CD16 expression (34.5% vs. 27.0%; P = 0.007) was observed. There was also a significant increase of D-dimers (2.0 vs. 0.2 microg/ml; P = 0.001), a decrease of antithrombin (83.5% vs. 102.0%; P = 0.004), but no increase of TAT complexes (1.7 vs. 1.5 microg/l; P = 0.38) or factor VII(a) (68.5% vs. 75.0%; P = 0.52). The increase of D-dimers was significantly correlated with the monocyte APC (R = 0.60; P = 0. 005), but not with monocyte tissue factor levels (R = -0.22; P = 0. 35) or TAT complexes (R = 0.12; P = 0.60). These results reflect a local rather than systemic thrombin and fibrin formation. It is suggested that the APC formed locally enters the circulation and binds to peripheral blood monocytes. APC bound on monocytes is known to inhibit monocyte cytokine production and might therefore be involved in regulatory responses of monocytes in cancer patients.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Blood Coagulation; Female; Fibrin Fibrinogen Degradation Products; Flow Cytometry; Humans; Male; Middle Aged; Monocytes; Neoplasms; Protein Binding; Protein C; Thromboplastin

Tissue factor (TF) is the main physiological initiator of blood coagulation and its activation or de-encryption within plasma membranes is important for trapping, extravasation and angiogenesis in the development and spread of solid malignancies. Multidrug resistance is also an adaptive response in malignant (and normal) cells. It is often mediated by the over-expression of the P-glycoprotein (P-gP) efflux pump. Both TF and P-gP tend to be expressed together, perhaps as part of a coherent 'crisis management' response of cells to environmental change or challenge. An associated feature in such a response appears to be the reversal of normal phospholipid charge asymmetry in the plasma membrane bilayer. Responses to environmental stimuli affect function in normal and malignant tissue. Uniting the study of TF expression or de-encryption and MDR-1 phenotype would be biologically enlightening and might ultimately influence clinical cancer management and the control of thrombotic problems associated with treatment.

Topics: ATP Binding Cassette Transporter, Subfamily B, Member 1; Drug Resistance, Multiple; Drug Resistance, Neoplasm; Humans; Neoplasms; Thromboplastin

Microparticles (MPs) resulting from vesiculation of platelets and other blood cells have been extensively documented in vitro and have been found in increased numbers in several vascular diseases, but little is known about MPs of endothelial origin. The aim of this study was to analyze morphological, immunological, and functional characteristics of MPs derived from human umbilical vein endothelial cells (HUVECs) stimulated by TNF, and to investigate whether these MPs are detectable in healthy individuals and in patients with a prothrombotic coagulation abnormality. Electron microscopy evidenced bleb formation on the membrane of TNF-stimulated HUVECs, leading to increased numbers of MPs released in the supernatant. These endothelial microparticles (EMPs) expressed the same antigenic determinants as the corresponding cell surface, both in resting and activated conditions. MPs derived from TNF-stimulated cells induced coagulation in vitro, via a tissue factor/factor VII-dependent pathway. The expression of E-selectin, ICAM-1, alphavbeta3, and PECAM-1 suggests that MPs have an adhesion potential in addition to their procoagulant activity. In patients, labeling with alphavbeta3 was selected to discriminate EMPs from those of other origins. We provide evidence that endothelial-derived MPs are detectable in normal human blood and are increased in patients with a coagulation abnormality characterized by the presence of lupus anticoagulant. Thus, MPs can be induced by TNF in vitro, and may participate in vivo in the dissemination of proadhesive and procoagulant activities in thrombotic disorders.

Topics: Antiphospholipid Syndrome; Autoimmune Diseases; Cell Adhesion Molecules; Cells, Cultured; Endothelium, Vascular; Factor VII; Flow Cytometry; Humans; Infections; Lupus Coagulation Inhibitor; Lupus Erythematosus, Systemic; Microscopy, Confocal; Neoplasms; Receptors, Vitronectin; Thrombophilia; Thromboplastin; Tumor Necrosis Factor-alpha; Umbilical Veins

Activation of blood coagulation is a common complication of cancer and inflammation in both humans and experimental animals. Increased production of tissue factor--the principal initiator of the coagulation process--by endothelial cells, monocytes, and macrophages has been implicated in these conditions.. To investigate whether urinary tissue factor (uTF) might reflect the state of monocyte/macrophage activation and be a useful diagnostic test.. Urine was centrifuged at 51,000 g to sediment tissue factor containing membrane vesicles. The tissue factor was then solubilised in beta-octyl-glucopyranoside and assayed in a specific chromogenic assay adapted for use in microtitre plates.. The assay proved to be sensitive, specific, and reproducible. The normal range of uTF was relatively narrow and unaffected by age, sex, or cigarette smoking. Levels were not significantly influenced by storage of urine samples before assay or by the presence of fresh blood in the urine sample.. This method may have diagnostic application in the study of haemostatic activation in patients with cancer and other disease states.

Topics: Biomarkers, Tumor; Blood Coagulation; Humans; Lymphocyte Activation; Macrophage Activation; Neoplasms; Predictive Value of Tests; Reproducibility of Results; Thromboplastin

Monocyte and urinary tissue factors (mTF and uTF) are both elevated in a number of pathologic conditions, including cancer. This study validates the best available uTF and mTF assays as diagnostic tools for cancer and examines if uTF levels reflect monocyte activation. Using kinetic chromogenic assays for uTF and mTF (measured on fresh resting cells [baseline], unstimulated cells, and lipopolysaccharide [LPS]-stimulated cells), we assessed TF levels in normal individuals, surgical controls, and patients with benign and malignant diseases. Each benign disease group was stratified as inflammatory or noninflammatory. Controls and benign noninflammatory results were indistinguishable. The malignant and inflammatory groups showed raised uTF levels over controls (p < 0.001). mTF levels differ similarly. For mTF and uTF assays, there was no significant difference between the malignant and inflammatory groups. The relative operating characteristic (ROC) curve plots sensitivity against false positive rate (1-specificity) for all possible cutoff values of a diagnostic test. Assay performance is assessed as the area under the curve (AUC). The ROC curve for the uTF assay displayed both sensitivity and specificity for cancer, the AUC being 0.83. Of the three mTF levels, LPS-stimulated cells gave the optimum curve (AUC = 0.71). uTF showed a weak to moderate association with mTF levels but correlated best and was statistically significant when compared with levels in the LPS-stimulated cells. uTF represents an intrinsic, kidney-derived, physiologic concentration rather than that of preactivated or postactivated monocytes. In conclusion, both uTF and LPS-stimulated mTF levels showed sensitivity and specificity in detecting cancer and inflammatory diseases. However, the two forms of TF appear to be independently derived.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Area Under Curve; Biomarkers, Tumor; Breast Neoplasms; Child; Child, Preschool; Cholelithiasis; Colorectal Neoplasms; Diagnosis, Differential; False Positive Reactions; Female; Hernia, Inguinal; Humans; Inflammation; Kidney Calculi; Lipopolysaccharides; Male; Middle Aged; Monocytes; Neoplasms; Prostatic Neoplasms; ROC Curve; Sensitivity and Specificity; Thromboplastin; Urinary Bladder Neoplasms

Topics: Endothelial Growth Factors; Gene Expression Regulation; Genetic Therapy; Humans; Neoplasms; Neovascularization, Pathologic; Thromboplastin

Topics: Animals; Antineoplastic Agents; Blood Coagulation; Clinical Trials as Topic; Endothelium, Vascular; Humans; Neoplasm Metastasis; Neoplasms; Neovascularization, Pathologic; Thromboplastin

Topics: Animals; Endothelium, Vascular; Humans; Neoplasms; Neovascularization, Pathologic; Thromboplastin

Thromboembolic complications are common in patients with malignant disease. We studied the activation of coagulation in 106 patients with solid tumours and 72 healthy volunteers by measuring plasma levels of tissue factor, factor VIIa, factor XIIa, thrombin-antithrombin complex, and prothrombin fragments 1 + 2. Tissue factor was 67% higher in cancer patients (median 582 vs 349 pg/mL, p = 0.0006) and factor VIIa was 46% higher (100 vs 69 mU/mL, p = 0.0002), indicating extrinsic pathway activation. Modest activation of the intrinsic pathway (elevated factor XIIa) was seen only in patients with advanced disease or those receiving chemotherapy. Excess thrombin generation was manifested by elevations in thrombin-antithrombin complex and prothrombin fragments 1 + 2. Tissue factor pathway is clearly implicated in the hypercoagulable state of cancer.

Topics: Blood Coagulation; Case-Control Studies; Factor VIIa; Hemostasis; Humans; Male; Middle Aged; Neoplasms; Platelet Activation; Thromboplastin; Thrombosis

We examined plasma antigen levels of tissue factor (TF) in 95 cases of disseminated intravascular coagulation (DIC), to investigate the role of TF in DIC. A significant elevation of plasma antigen levels of TF was observed in cases of DIC associated with cancer. However, no such significant elevation was observed in cases of DIC associated with acute promyelocytic leukemia (APL), acute leukemia except APL, blastic crisis of chronic myelogenous leukemia, non-Hodgkin lymphoma (NHL), sepsis or fulminant hepatitis. No significant elevation of TF was observed in patients without DIC, except 4 cases of cancer who developed DIC thereafter. Plasma antigen levels of TF were higher in both cases of DIC with renal failure and chronic renal failure without DIC than its levels in those without renal failure. Therefore, plasma antigen levels of TF in DIC patients with renal failure were considered to be carefully estimated. The levels of TF were decreased with the clinical improvement in some cases of DIC but were further increased or remained at high levels in patients who showed no improvement of DIC. Thus, plasma antigen levels of TF is an important marker to predict the development and/or prognosis of DIC, especially in patients with cancer.

Topics: Adult; Disseminated Intravascular Coagulation; Female; Humans; Male; Neoplasms; Prognosis; Renal Insufficiency; Thromboplastin

Tissue factor (TF), a 47 kDa transmembrane glycoprotein, is the essential receptor and cofactor for factor VII/VIIa. Its distribution in normal tissues and in tumours has been recently investigated immunohistochemically with monoclonal and polyclonal anti-TF antibodies in frozen sections. The cardinal problem of this technique is the difficulty of determining exactly the localization of the reaction product at least in certain tissues. Here, we demonstrate a method using monoclonal anti-TF antibodies to detect TF in routinely fixed, microwaved, paraffin-embedded tissues. Generally, there were no fundamental differences in TF distribution in frozen and paraffin-embedded material. However, in most cases, the paraffin sections allow a better cellular localization of TF. For example, the staining pattern for TF in both kinds of sections is identical in kidney, brain and skin. The paraffin-embedded material, however, clearly shows that TF expression is restricted to the parietal and the visceral epithelia of Bowman's capsule of glomeruli in the kidney, and to astrocytes and their processes in the brain. TF reactivity in the skin is revealed to be cell membrane-bound; in cardiomyocytes TF shows an exclusively sarcolemmal localization. The immunohistological detection of TF in paraffin sections is a powerful tool for systematic studies on the possible role of TF in the context of physiological and pathological studies.

Topics: Antibodies, Monoclonal; Cryopreservation; Humans; Immunohistochemistry; Microwaves; Neoplasms; Paraffin Embedding; Thromboplastin; Tissue Fixation

Tissue factor (TF), the primary initiator of blood coagulation in vivo, is expressed in vitro by a variety of cells. Previous efforts to localize TF in tissue and cells have been limited principally to the use of immunological techniques. In the present study, we describe a novel functional probe for TF expression, which can be utilized to localize functional TF in situ in human cells and tissues. This probe, a biotinylated phe-pro-arg-chloro-methyl-ketone-labeled rVIIa (FPR-ck-VIIa), interacts with TF via high-affinity binding sites. The binding of FPR-ck-VIIa, therefore, can be correlated with the ability of TF to activate clotting. In the described studies, TF antigen (TF:Ag) expression was examined immunohistochemically with various TF-specific monoclonal antibodies (MAbs) and was correlated with functional TF expression using our novel TF-binding probe (eg, FPR-ck-VIIa). Initial results indicate that TF:Ag expression correlates with the expression of functional TF (TF:VIIa), and the specificity of both types of probes was confirmed. Parallel antigenic and functional TF expression in situ was demonstrated in various human tumors. We believe this to be the first demonstration of functional TF in situ in human cells and tissues. We suggest that FPR-ck-VIIa should prove a useful reagent for studying the role of TF in the pathogenesis of clotting complications of human disease.

Topics: Amino Acid Chloromethyl Ketones; Antibodies, Monoclonal; Antigens; Factor VIIa; Humans; Neoplasms; Recombinant Proteins; Thromboplastin; Tumor Cells, Cultured

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

This study was performed in order to separate plasma fractions of tissue factor pathway inhibitor (TFPI) on the basis of TFPI's heparin binding properties. A main goal was to look for differences in anticoagulant effect of the TFPI fractions from plasma. Normal plasma and plasma with increased amounts of TFPI were used; plasma from cancer patients and post-heparin plasma (plasma drawn 5 min after heparin injection). Heparin affinity chromatography separated plasma TFPI into four fractions with increasing heparin affinity: the flow-through fraction, a low affinity fraction eluting at less than 0.3 M NaCl, an intermediate affinity fraction eluting at 0.3-0.55 M NaCl and a high affinity fraction eluting at 0.55-1.0 M NaCl. These fractions corresponded partly to the three TFPI activity fractions obtained by gel filtration. In plasma from cancer patients, the two fractions with intermediate and high heparin affinity were increased three- to four-fold, compared to normal plasma. The TFPI activity in these two fractions eluted with low-molecular-weight (35-60 kD) on gel filtration. In post-heparin plasma an even larger increase in the fraction with high heparin affinity was found; compared to that in normal plasma it was increased 14-fold. TFPI was purified to 0.72 U/mg protein in this fraction (about 43-fold compared to normal plasma TFPI). The anticoagulant effect of TFPI, relative to the chromogenic substrate TFPI activity, was greater in plasma fractions with high heparin affinity than in the other plasma TFPI fractions, and it was five-fold greater than the anticoagulant effect of recombinant TFPI. Thus, plasma TFPI is heterogenous in heparin affinity and in anticoagulant potency.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adult; Anticoagulants; Antithrombins; Apolipoprotein A-I; Apolipoprotein A-II; Apolipoproteins B; Chromatography, Affinity; Chromatography, Gel; Factor VII; Female; Heparin; Humans; Lipoproteins; Male; Middle Aged; Neoplasms; Prothrombin Time; Thromboplastin

Fifteen patients undergoing major surgical procedures were evaluated for lipoprotein associated coagulation inhibitor (LACI) antigen, factor VII (F VII), antithrombin III (AT III), and peripheral blood monocyte tissue factor (TF) activity immediately before surgery and on following days. A peak in monocyte TF activity occurred between the first and fifth days after surgery in 10 of the patients, while LACI, F VII, and AT III levels dropped in a qualitatively parallel manner in 8 of these patients. LACI, F VII, and AT III levels decreased after surgery in two additional patients even though TF activity also decreased after surgery in these patients. In the remaining 3 patients who developed infections during the study, TF activity rose within 2 days of the diagnosis of infection in addition to the postoperative peak. In two of these patients, LACI levels increased dramatically near the end of the study period without concomitant changes in F VII and AT III. Overall, the presurgical TF levels in disrupted monocytes varied 52-fold and the maximal TF activity varied 24-fold among patients. The TF response following surgery is therefore heterogenous in both temporal occurrence and magnitude of the postsurgical peak. The patients also varied considerably in the presurgical levels of monocyte TF activity. A possible association between the level of presurgical TF activity and the magnitude of the postsurgical peak was noted.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Antithrombin III; Factor VII; Female; Humans; Lipoproteins; Male; Monocytes; Neoplasms; Protease Inhibitors; Reference Values; Surgical Procedures, Operative; Thromboplastin; Time Factors

The influence of Extrinsic pathway inhibitor (EPI) on global clotting times of plasma was studied using activity-blocking IgG antibodies. Dilute tissue thromboplastin (TP) clotting times in plasma collected after intravenous injection of heparin were dramatically shortened by the addition of anti-EPI IgG. Anti-EPI IgG shortened the TP times to a lesser degree in plasma heparinized in vitro. Compared to plasma heparinized in vitro, the TP clotting times were markedly prolonged in post-heparin plasma of equal heparin concentration. Addition of anti-antithrombin IgG reduced the clotting times somewhat more than did anti-EPI IgG, particularly in normal plasma. In plasma from patients with cancer, about equal effect was obtained by blocking either EPI or antithrombin. These clotting time studies suggested that much of the anticoagulant effect caused by injection of heparin depended on EPI. This was confirmed by recording the release of fibrinopeptide A (FPA), as marker of thrombin generation, following addition of TP and CaCl2 to citrated blood. Thrombin generation was delayed and markedly reduced in post-heparin blood compared to that in normal blood. After incubating post-heparin citrated blood with anti-EPI IgG, the generation of FPA was more rapid; the amounts released 30 seconds after addition of TP were 6 times greater (36 vs 6 ng/ml) than in post-heparin blood without anti-EPI IgG. The subsequent FPA values were midway between pre-injection and post-heparin values. In conclusion, between one third and one half of the inhibition of TP-initiated coagulation in post-heparin plasma depends on EPI. This inhibition is mainly due to inactivation of the factor VIIa-TP complex. A small, but distinct contributing effect observed in the APTT assay (and hence no TP) indicates that even increased inactivation of activated factor X contributes. In cancer patients, these EPI-heparin interactions contribute even more to the anticoagulant effects of heparin.

Topics: Antithrombins; Dose-Response Relationship, Drug; Factor VII; Fibrinopeptide A; Heparin; Humans; Lipoproteins; Neoplasms; Partial Thromboplastin Time; Thromboplastin

Topics: Adult; Aged; Disseminated Intravascular Coagulation; Female; Humans; Male; Middle Aged; Neoplasms; Thromboplastin

Topics: Aged; Endothelium, Vascular; Factor VII; Female; Heparin; Humans; Lipoproteins; Male; Middle Aged; Neoplasm Metastasis; Neoplasms; Thromboplastin

Topics: Arthritis, Rheumatoid; Female; Fibrocystic Breast Disease; Humans; Inflammatory Bowel Diseases; Male; Neoplasms; Thromboplastin

Serial determinations of plasma coagulation inhibitor levels were performed with chromogenic substrate activity assays in 7 patients with cancer. At time of diagnosis normal median activities of Antithrombin, Protein C, Heparin Cofactor II and Extrinsic Pathway Inhibitor were found. The inhibitor activities changed significantly with the progress of malignant disease; Antithrombin, Protein C and Heparin Cofactor II decreased whereas Extrinsic Pathway Inhibitor increased. Determinations in 13 additional patients in the terminal phase of cancer confirmed this finding. The inhibitor activities were expressed in per cent of a pooled reference plasma. In the total series of 20 patients studied, median activity of Extrinsic Pathway Inhibitor was 183% (range 61-378%) and significantly (p less than 0.005) above age-adjusted normal reference 10 days (range 1-20 days) prior to death. Median activities of Antithrombin was 59% (range 20-109%), of Protein C 54% (range 24-130%) and Heparin Cofactor II 59% (range 33-110%), all significantly below age adjusted normal reference (p less than 0.001). The coagulation inhibitor levels seem related to the stage of disease in patients with cancer.

Topics: Aged; Antithrombins; Blood Coagulation; Factor VII; Female; Heparin Cofactor II; Humans; Liver Neoplasms; Male; Middle Aged; Neoplasms; Protein C; Thromboplastin

Generation of thromboplastin by monocytes has been shown to play a vital role in hypercoagulable states seen in malignancy. The purpose of this study was to compare the procoagulant activity in cancer patients and controls. Recalcification times (RT) of whole blood from 19 normal volunteers, 8 patients with benign polyps, 12 patients previously treated by surgery for head and neck (H&N) or colon cancer, and 13 untreated patients with various stages of H&N or colon cancer were determined. Tests were performed with and without stimulation with Escherichia coli endotoxin. The mean RT in saline (RTS) of untreated patients with early cancer (4.58 +/- 0.83 min) and that of patients with advanced cancer (5.23 +/- 1.16 min) were lower than that of controls (6.55 +/- 0.82 min), P less than 0.01 and P less than 0.05, respectively. The RTS of patients previously treated and of those with benign polyps were no different from those of controls. Activation with endotoxin significantly lowered the recalcification times (RTE) in the early (3.90 +/- 0.58 min) and advanced cancer patients (4.23 +/- 0.66 min) compared to the RTE of controls (5.69 +/- 0.75 min, P less than 0.01 for both groups) as well as compared to those with benign tumors, P less than 0.05. The mean RTE of previously treated patients (4.72 +/- 0.58 min) was also lower than that of controls, P less than 0.05. Our results suggest that RT is significantly reduced in cancer patients compared to that of controls. Furthermore, monocyte activation with endotoxin may enable us to distinguish cancer patients from controls as well as from those with benign tumors.

Topics: Adenoma; Adult; Blood Coagulation Tests; Carcinoma, Squamous Cell; Colonic Neoplasms; Head and Neck Neoplasms; Humans; Male; Middle Aged; Monocytes; Neoplasms; Thromboplastin

In tumor cell thrombosis thrombin does not only act as clotting enzyme but also as tissue hormone stimulating the proliferation of malignant cells indicated by an increase of cell count and thymidine uptake in cell cultures. Spontaneous and by cytostatic treatment induced decay of tumor cells induces the release of tumor cell thromboplastins which activate locally the clotting system and liberate thrombin. This local liberation of thrombin in tumor cell thrombosis stimulates again tumor cell proliferation and represents a biochemical substrate of tumor spread and growth in tumor cell thrombosis.

Topics: Cell Division; DNA Replication; Fibrinopeptide A; Growth Substances; Humans; Neoplasms; Thrombin; Thromboplastin; Thrombosis; Thymidine; Tritium

In this study we have looked for differences in coagulation parameters before and after surgical removal of benign or malignant tumours. A striking increase in thromboplastin activity of the blood monocytes was seen 1 d after surgery. This paralleled a fall in factor VII activity. At the same time, the sensitivity of the blood monocytes to stimulation by endotoxin increased significantly. We propose from this study that monocyte thromboplastin may be a postoperative thrombogenic factor. Increased levels of factor VIII and fibrinogen 2-3 d postoperatively were found, probably caused by inflammation reactions induced by the surgery. No difference in coagulation parameters could be demonstrated between patients with benign, noninvasive lesions and patients with invasive, carcinomatous lesions.

Topics: Blood Coagulation; Breast Neoplasms; Factor VII; Factor VIII; Female; Fibrinogen; Humans; Male; Monocytes; Neoplasms; Postoperative Period; Prostatic Hyperplasia; Thromboplastin; Thyroid Neoplasms; Time Factors; Urinary Bladder Neoplasms

Topics: Antibodies; Aspirin; Blood Coagulation Disorders; Blood Coagulation Factors; Blood Platelets; Cell Adhesion; Cell Communication; Cyclooxygenase Inhibitors; Disseminated Intravascular Coagulation; Epoprostenol; Fibrin Fibrinogen Degradation Products; Fibrinogen; Fibrinopeptide A; Humans; Indomethacin; Monocytes; Neoplasm Transplantation; Neoplasms; Syndrome; Thrombocytopenia; Thrombocytosis; Thromboembolism; Thromboplastin

The expression of tissue factor activity was evaluated in homogenates and in intact whole cells from a variety of human and nonhuman cell lines of normal and neoplastic origin. A high degree of species specificity in the interaction of tissue factor with other coagulation factors was observed in guinea pig, rat, mouse, and hamster cells. Tissue factor was present in significant amounts in homogenates of both the normal and neoplastic cells tested in all four species examined. No correlation was observed between the amount of tissue factor detected in cell homogenates and the derivation of the cell line from normal versus neoplastic tissue. Intact cells also expressed tissue factor activity, but lower levels were found in most cell lines examined. The significance of these data is discussed with regard to fibrin deposition around tumors in vivo.

Topics: Animals; Brain Chemistry; Cell Line; Factor VII; Factor VIIa; Factor X; Fibrin; Guinea Pigs; Humans; Membrane Proteins; Mice; Neoplasms; Rats; Skin; Species Specificity; Thromboplastin

Topics: Animals; Anticoagulants; Blood Coagulation; Blood Coagulation Disorders; Blood Coagulation Factors; Cysteine Endopeptidases; Disseminated Intravascular Coagulation; Endopeptidases; Factor X; Factor Xa; Female; Fibrin Fibrinogen Degradation Products; Fibrinolysis; Hemorrhage; Humans; Male; Neoplasm Metastasis; Neoplasm Proteins; Neoplasms; Neoplasms, Experimental; Thromboembolism; Thromboplastin

Analysis of fresh surgical specimens of normal tissue and tumor tissue show a cellular antithrombin activity to be present in certain organs. In normal tissues it was noted chiefly in normal colon, testes, breast, and uterus. In malignant tissues it was prominent in adenocarcinomas of the colon, breast, and lung. No epidermoid tumors showed evidence of thrombin binding. The thrombin- binding activity required the presence of intact cells and was distinct from the soluble antithrombins normally present in plasma and serum. There is growing evidence to suggest an interrelationship between clotting and the growth and dissemination of cancer. The implications of cellular antithrombins are reviewed in this context.

Topics: Adenocarcinoma; Antithrombins; Blood Coagulation Tests; Carcinoma, Squamous Cell; Female; Humans; Lymphoma; Male; Neoplasms; Thrombin Time; Thromboplastin

Topics: Blood Coagulation; Cell Line; Fibrinolysis; Humans; Neoplasms; Neoplasms, Experimental; Plasminogen Activators; Thromboplastin

Cancer procoagulant A (CPA) was originally described in extracts of tumor tissue, but whether this represented a quantitative and/or a qualitative difference from procoagulant activity in normal tissue extracts was not clear. Procoagulant activity was quantitated in extracts of 12 matched normal and malignant human tissue samples from the large intestine, breast, lung, and kidney. The specific activity of procoagulants in the tumor extracts was not greater than that in the extracts of normal tissue. Two enzymatic characteristics of CPA that distinguish it from tissue thromboplastin are its inhibition by diisopropylfluorophosphate (DFP) and its lack of dependence on factor VII. These specific tests were used to evaluate qualitative differences between procoagulants from normal and malignant intestinal tissues. In the paired normal and malignant tissue extracts, all tumor samples were inhibited by DFP and were active in factor VII-depleted bovine plasma (F7D-BP). In contrast, the extracts of normal tissue were insensitive to DFP and, except for one extract, were inactive in F7D-BP. Four of 9 other tumor extracts (44%) were positive for both of these tests for CPA, whereas the other 5 extracts were positive for only one of the two tests. The results suggest that extracts of normal and malignant tissues contained similar levels of procoagulant. However, malignant tissue contained a procoagulant enzymatically different from normal tissue thromboplastin. Furthermore, most of the malignant tissue extracts seemed to contain little or no thromboplastin.

Topics: Blood Coagulation Factors; Factor VII; Female; Humans; Isoflurophate; Neoplasms; Thromboplastin; Tissue Distribution

Thromboplastic and fibrinolytic activities of 14 lines of cultured human cancer cells were estimated by modified Astrup's methods. High tissue thromboplastic activity was found in one line of urinary-bladder cancer, 2 lines of gastric cancer and one line of lung cancer, but no activity was found in 6 lines of lung cancer. High fibrinolytic activity was noted in one line of gastric cancer and 2 lines of lung cancer, but no activity was seen in 6 lines of lung cancer and one line of gastric cancer. No plasmin activity was found. The tumour cell lines could be classified into 3 groups on the basis of the 2 activities. Cancer cell lines could also be classified into 2 groups: with high or low release of thromboplastin into culture media. Fibrinolytic activity was found in the culture media of all cell lines with high fibrinolytic activity. Fibrinolytic activity, but not thromboplastic activity, seemed to be influenced by the constituents of culture media. No definite correlation was found between the 2 activities and the histological types of the parent tumours of the cultured cells.

Topics: Blood Coagulation; Cell Line; Factor IX; Factor VII; Fibrinolysis; Humans; Lung Neoplasms; Neoplasms; Stomach Neoplasms; Thromboplastin; Urinary Bladder Neoplasms

Topics: Adult; Aged; Animals; Blood Coagulation Disorders; Carcinoma, Bronchogenic; Carcinoma, Ehrlich Tumor; Disseminated Intravascular Coagulation; Female; Fibrin Fibrinogen Degradation Products; Fibrinogen; Fibrinolysin; Fibrinolysis; Heparin; Humans; Lung Neoplasms; Male; Mice; Middle Aged; Neoplasm Metastasis; Neoplasms; Neoplastic Cells, Circulating; Thromboembolism; Thromboplastin

Topics: Animals; Blood Coagulation; Cattle; Enzyme Precursors; Factor VII; Factor X; Fibrinogen; Humans; Neoplasms; Peptide Hydrolases; Rabbits; Thromboplastin

Topics: Blood Coagulation Factors; Brain; Cell Biology; Cell Survival; Fibrin; In Vitro Techniques; Iodine Radioisotopes; Neoplasms; Radiation Effects; Thromboplastin; Tissue Extracts

Topics: Adult; Blood Cell Count; Blood Platelet Disorders; Blood Platelets; Child; Child, Preschool; Clot Retraction; Female; Humans; Male; Middle Aged; Neoplasms; Prothrombin Time; Thrombocytopenia; Thrombocytosis; Thromboplastin

Experiments were undertaken to test a new hypothesis for the mechanism underlying the Révész effect. The hypothesis proposes that lethally irradiated (LI) tumour cells enhance the take probability of a small number of transplanted viable (V) tumour cells mixed with them by exerting a thromboplastic effect at the site of injection; local fibrin formation prevents emigration of V cells from the site or secures their survival there. The evidence presented to support this hypothesis is as follows: in the case of 3 isogeneically transplanted tumours, admixed particulate brain extract simulated the effect of LI cells in increasing the take probability of V cells; brain extract simulated the effect of LI cells in greatly delaying the disappearance of (125)IUdR-labelled viable carcinoma cells from the injection site; V cells acquired a raised take probability by their incorporation in fibrin clots; it was confirmed that admixed erythrocytes increased the take probability of V cells; using a newly devised microscopical test for detection of the thromboplastic activity of individual cells, it was found that cell death was almost always required for the display of such activity; lymphocytes and bone marrow cells, ineffective in enhancing the take of V cells, were almost totally devoid of thromboplastic activity. Possible explanations are given for failure of a fibrinogen depleting agent, ancrod (Arvin) to inhibit the Révész effect when administered to recipients. It is concluded that the evidence strongly supports the hypothesis presented whilst seriously weakening the long-standing theories that admixed LI cells act by provision of nutrients or by local quenching of postulated immune reactivity.

Topics: Animals; Brain; Cell Line; Cell Survival; Fibrin; Leukemia, Experimental; Mice; Mice, Inbred Strains; Neoplasm Metastasis; Neoplasm Transplantation; Neoplasms; Neoplasms, Experimental; Peptide Hydrolases; Radiation Effects; Thromboplastin; Tissue Extracts; Venoms

Topics: Animals; Fibrinogen; Fibrinolysis; Iodine Isotopes; Neoplasms; Neoplasms, Experimental; Rats; Thromboplastin

Topics: Animals; Fibrin; Hospitals; Humans; Ireland; Neoplasms; Neoplasms, Experimental; Research; Thrombin; Thromboplastin

Topics: Adenine Nucleotides; Blood Coagulation; Blood Coagulation Tests; Blood Platelets; Factor V; Factor VIII; Fibrinogen; Humans; Neoplasms; Prothrombin Time; Thrombin; Thromboplastin

Topics: Aprotinin; Hemorrhage; Humans; Neoplasms; Thromboplastin

Topics: Chromatography; Extraembryonic Membranes; Fatty Acids, Nonesterified; Humans; Neoplasms; Thromboplastin

Topics: Biological Assay; Blood Cell Count; Blood Coagulation Disorders; Blood Coagulation Factors; Blood Coagulation Tests; Blood Platelet Disorders; Female; Fibrin; Humans; Immunoelectrophoresis; Male; Neoplasms; Thrombin; Thrombocytopenia; Thromboplastin

Topics: Adult; Beta-Globulins; Blood Coagulation Factors; Blood Coagulation Tests; Cellulose; Chromatography, Gel; Communicable Diseases; Electrophoresis; Erythrocytes; Escherichia coli; Female; Fibrinolytic Agents; Heart Failure; Hemostatics; Humans; Kidney Diseases; Leukocytes; Male; Middle Aged; Neoplasms; Proteus; Pseudomonas; Staphylococcus; Thromboplastin

Topics: Cell Nucleus; Cytoplasm; Extraembryonic Membranes; Fibrin; Humans; Metabolism; Microsomes; Mitochondria; Neoplasms; Nitrogen; Phosphorus; Research; Thromboplastin

Topics: Adrenal Cortex Hormones; Anticoagulants; Arteriosclerosis; Blood Platelet Disorders; Coronary Disease; Fats; Female; Humans; Intracranial Embolism; Intracranial Embolism and Thrombosis; Neoplasms; Pharmacology; Postoperative Complications; Pregnancy; Pregnancy Complications; Pregnancy Complications, Hematologic; Thrombophilia; Thromboplastin; Thrombosis

Topics: Factor Xa; Leadership; Neoplasms; Thromboplastin

Topics: Adrenalectomy; Animals; Castration; Factor Xa; Humans; Male; Neoplasms; Orchiectomy; Parathyroid Glands; Sarcoma, Experimental; Thromboplastin; Thyroid Gland

Topics: DNA; Liver; Neoplasms; Personnel Turnover; Thromboplastin

Topics: Catalase; Endotoxins; Humans; Mental Disorders; Neoplasms; Thromboplastin

Topics: Animals; Breast Neoplasms; Dienestrol; Humans; Neoplasms; Neoplasms, Experimental; Rats; Thromboplastin

Topics: Humans; Knowledge; Neoplasms; Thromboplastin

Topics: Neoplasms; Thromboplastin