Tissue factor expression and angiogenesis in human prostate carcinoma

Tissue factor (coagulation factor III): a potential double-edge molecule to be targeted and re-targeted toward cancer

Tissue factor (TF) is a protein that plays a critical role in blood clotting, but recent research has also shown its involvement in cancer development and progression. Herein, we provide an overview of the structure of TF and its involvement in signaling pathways that promote cancer cell proliferation and survival, such as the PI3K/AKT and MAPK pathways. TF overexpression is associated with increased tumor aggressiveness and poor prognosis in various cancers. The review also explores TF's role in promoting cancer cell metastasis, angiogenesis, and venous thromboembolism (VTE). Of note, various TF-targeted therapies, including monoclonal antibodies, small molecule inhibitors, and immunotherapies have been developed, and preclinical and clinical studies demonstrating the efficacy of these therapies in various cancer types are now being evaluated. The potential for re-targeting TF toward cancer cells using TF-conjugated nanoparticles, which have shown promising results in preclinical studies is another intriguing approach in the path of cancer treatment. Although there are still many challenges, TF could possibly be a potential molecule to be used for further cancer therapy as some TF-targeted therapies like Seagen and Genmab's tisotumab vedotin have gained FDA approval for treatment of cervical cancer. Overall, based on the overviewed studies, this review article provides an in-depth overview of the crucial role that TF plays in cancer development and progression, and emphasizes the potential of TF-targeted and re-targeted therapies as potential approaches for the treatment of cancer.

A Novel Risk Score (P-score) Based on a Three-Gene Signature, for Estimating the Risk of Prostate Cancer-Specific Mortality

Purpose

To develop and validate a risk score (P-score) algorithm which includes previously described three-gene signature and clinicopathological parameters to predict the risk of death from prostate cancer (PCa) in a retrospective cohort.

Patients and Methods

A total of 591 PCa patients diagnosed between 2003 and 2008 in Stockholm, Sweden, with a median clinical follow-up time of 7.6 years (1–11 years) were included in this study. Expression of a three-gene signature (IGFBP3, F3, VGLL3) was measured in formalin-fixed paraffin-embedded material from diagnostic core needle biopsies (CNB) of these patients. A point-based scoring system based on a Fine-Gray competing risk model was used to establish the P-score based on the three-gene signature combined with PSA value, Gleason score and tumor stage at diagnosis. The endpoint was PCa-specific mortality, while other causes of death were treated as a competing risk. Out of the 591 patients, 315 patients (estimation cohort) were selected to develop the P-score. The P-score was subsequently validated in an independent validation cohort of 276 patients.

Results

The P-score was established ranging from the integers 0 to 15. Each one-unit increase was associated with a hazard ratio of 1.39 (95% confidence interval: 1.27–1.51, p < 0.001). The P-score was validated and performed better in predicting PCa-specific mortality than both D’Amico (0.76 vs 0.70) and NCCN (0.76 vs 0.71) by using the concordance index for competing risk. Similar improvement patterns are shown by time-dependent area under the curve. As demonstrated by cumulative incidence function, both P-score and gene signature stratified PCa patients into significantly different risk groups.

Conclusion

We developed the P-score, a risk stratification system for newly diagnosed PCa patients by integrating a three-gene signature measured in CNB tissue. The P-score could provide valuable decision support to distinguish PCa patients with favorable and unfavorable outcomes and hence improve treatment decisions.

Tissue Factor Expression in Colorectal Adenocarcinoma: Association with Angiogenesis and Clinical and Pathological Aspects

Introduction Tissue factor (TF) expression has been described in various neoplasms and was correlated with angiogenesis and metastases.

Objectives To describe TF expression in colorectal cancers, correlating it with microvessel density and clinical and pathological variables.

Methods Immunohistochemistry was used to determine TF expression and microvessel density. The Student t-test was used to compare high and low TF expression with microvessel density and with age. The chi-squared test was used for other comparisons, and Kaplan-Meier curves were used for survival analyses.

Results Forty-three patients were operated with curative intent. Their mean age was 58.1 ± 12.6 years old, and 62.8% were male. The rectum was the most common location (60,4%), and most tumors reached the serosa and peri-intestinal fat (72.1%). Lymph nodes were positive in 46.5%, and 72.1% of the tumors were moderately differentiated adenocarcinomas. Death occurred in 27.6 ± 12.8 months in 51.1% of the patients who had recurrence. Tissue factor expression was intense in 88.4%. There was a positive correlation between TF expression and microvessel density (p = 0.02), and between TF and older age (p < 0.01). There was no correlation between TF expression and other variables (gender, histological type, penetration into the intestinal wall, and lymphatic and systemic metastases). Tissue factor expression did not correlate with survival.

Conclusion Tissue factor expression correlated with increased microvessel density and older age. Further studies are necessary to ascertain the clinical relevance of TF in colorectal cancer.

Intracerebral Hemorrhaging Due to Coagulopathy Caused by Latent Advanced Prostate Cancer

A patient with no medical history was admitted to our hospital with consciousness disturbance and diagnosed with intracerebral hemorrhaging in the bilateral hemisphere based on computed tomography. A blood test showed an abnormal coagulation capacity. He died of intracerebral hemorrhaging 11 hours after the onset. An autopsy revealed latent advanced prostate cancer metastasis to multiple organs. Notably, we found no evidence of intracerebral hemorrhaging, including arteriovenous malformation or cancer metastasis, in the brain. He was ultimately diagnosed with intracerebral hemorrhaging due to coagulopathy associated with latent advanced prostate cancer. Coagulopathy caused by advanced prostate cancer, which was first identified by autopsy, can lead to intracerebral hemorrhaging.

Tumor Microenvironment in Prostate Cancer: Toward Identification of Novel Molecular Biomarkers for Diagnosis, Prognosis, and Therapy Development

Prostate cancer (PCa) is by far the most commonly diagnosed cancer in men worldwide. Despite sensitivity to androgen deprivation, patients with advanced disease eventually develop resistance to therapy and may die of metastatic castration-resistant prostate cancer (mCRPC). A key challenge in the management of PCa is the clinical heterogeneity that is hard to predict using existing biomarkers. Defining molecular biomarkers for PCa that can reliably aid in diagnosis and distinguishing patients who require aggressive therapy from those who should avoid overtreatment is a significant unmet need. Mechanisms underlying the development of PCa are not confined to cancer epithelial cells, but also involve the tumor microenvironment. The crosstalk between epithelial cells and stroma in PCa has been shown to play an integral role in disease progression and metastasis. A number of key markers of reactive stroma has been identified including stem/progenitor cell markers, stromal-derived mediators of inflammation, regulators of angiogenesis, connective tissue growth factors, wingless homologs (Wnts), and integrins. Here, we provide a synopsis of the stromal-epithelial crosstalk in PCa focusing on the relevant molecular biomarkers pertaining to the tumor microenvironment and their role in diagnosis, prognosis, and therapy development.

Beyond thrombosis: the impact of tissue factor signaling in cancer

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.

Elevated Microparticles, Thrombin-antithrombin and VEGF Levels in Colorectal Cancer Patients Undergoing Chemotherapy

Hypercoagulable state and neoangiogenesis are common phenomena associated with malignancy. Cancer patients have increased levels of circulating endothelium-derived microparticles (EMPs), which have been hypothesized to be involved in numerous pathophysiological processes. Hemostasis and angiogenesis are also activated in colorectal cancer (CRC) patients. The study aimed to investigate potential influence of chemotherapy on EMPs, thrombin anti-thrombin complex (TAT) and vascular endothelial growth factor (VEGF) levels in CRC patients undergoing chemotherapy. The study group consisted of 18 CRC patients: 8 stage III colon cancer (CC) and 10 stage IV rectal cancer (RC) patients. EMPs, TAT and VEGF levels were assessed before chemotherapy and after the third course. Results were compared with 10 healthy subjects. EMP concentration was measured by flow cytometry, while TAT and VEGF concentrations were assayed employing ELISA. Compared to the control group, CC and RC patients had significantly higher levels of tissue factor (TF)-bearing and non-TF-bearing EMPs before and after three courses of chemotherapy. VEGF concentrations in CRC patients were higher than in the control groups and increased following chemotherapy. TAT levels were elevated in CRC patients before chemotherapy compared to healthy subjects and significantly increased after the third course of chemotherapy. No significant correlation was found either between EMP and TAT levels, or between EMP concentrations and VEGF levels in the study group. CRC patients have increased EMPs, and TAT as well as VEGF levels tend to increase during chemotherapy.

Down-regulation of tissue factor inhibits invasion and metastasis of non-small cell lung cancer

Objective: Tissue factor (TF) is clinically identified as a marker for the detection of various types of cancer as well as the prediction of prognosis for cancer patients. This present study aims to explore the possibility and feasibility to use plasma TF as a biomarker for the prediction of prognosis of patients with non-small cell lung cancer (NSCLC).

Methods: A total of 100 patients with NSCLC at stage I to IV was included in the study, in whom the expression of plasma TF was detected. The Cox proportional-hazards regression model was then used to analyze the collected information, attempting to identify how patients' overall survival (OS) was associated with the expression of plasma TF. To verify the function of TF in invasion and metastasis, the expression of plasma TF was downregulated by SiRNA both in vivo and in vitro.

Results: The expression of plasma TF in NSCLC patients was related to the diagnosis age of the patient. It was noted that patients with high TF expression levels tended to have worse OS performance, which implied that TF could be used as a marker for patients with stage I-IV NSCLC (HR = 2.030, 95% CI = 1.21-3.398, P = 0.007). TF down-regulation inhibited the growth of tumor in vitro as well as the metastasis and invasion of NSCLC cells in vivo.

Conclusion: Both in vivo and in vitro, the invasion and migration of NSCLC cells are suppressed by TF knockdown. TF has the potential to become an effective biomarker for the prediction of prognosis of patients with stage I-IV NSCLC.

Procoagulant tumor microvesicles attach to endothelial cells on biochips under microfluidic flow

Tumor patients are at a high risk of venous thromboembolism (VTE), and the mechanism by which this occurs may involve tumor-derived microvesicles (MVs). Previously, it has been shown that tumor MVs become attached to endothelial cells in static conditions. To investigate whether this process occurs under physiologically relevant flow rates, tumor MVs were perfused across a microfluidic device coated with growing human umbilical vein endothelial cells (HUVECs). Cell lines were screened for their ability to form tumor spheroids, and two cell lines, ES-2 and U87, were selected; spheroids formed were transferred to a microfluidic chip, and a second endothelial cell biochip was coated with HUVECs and the two chips were linked. Media flowed through the spheroid chip to the endothelial chip, and procoagulant activity (PCA) of the tumor media was determined by a one-stage prothrombin time assay. Tumor MVs were also quantified by flow cytometry before and after interaction with HUVECs. Confocal images showed that HUVECs acquired fluorescence from MV attachment. Labeled MVs were proportionally lost from MV rich media with time when flowed over HUVECs and were not observed on a control chip. The loss of MV was accompanied by a proportional reduction in PCA. Flow cytometry, confocal microscopy, and live flow imagery captured under pulsatile flow confirmed an association between tumor MVs and HUVECs. Tumor MVs attached to endothelial cells under physiological flow rates, which may be relevant to the VTE pathways in cancer patients.

Tissue factor expression predicts outcome in children with neuroblastoma: A retrospective study

Previous studies have revealed that the processes of tumor angiogenesis, metastasis and invasiveness are highly dependent on components of the blood coagulation cascade. Tissue factor (TF) is one of the key proteins in coagulation. Cumulative evidence suggested that in addition to its role in coagulation, TF regulates intracellular signaling pathways that serve an important role in angiogenesis, tumor development and metastasis. In the present study, TF expression in neuroblastoma as well as its association with tumor stage, pathology and outcome were assessed. A total of 40 formalin-fixed paraffin-embedded tissues were evaluated for TF expression by immunohistochemical analysis. Results revealed that TF expression was positive in 75% of the analyzed tumor tissues. No significant association between TF expression and sex, age, tumor stage or disease pathology was observed. MYCN proto-oncogene bHLH transcription factor (MYCN) was upregulated in 45% (n=18) of the study cases. Positive TF expression was observed in 94.4% of patients (n=17) with upregulated MYCN, while 59% of patients (n=13) with normal MYCN showed positive TF expression (P<0.05). TF expression was a significant outcome predictor for patients; 18/30 patients (60%) with positive TF expression succumbed to the disease during the study period. In conclusion, TF may be a promising prognosis indicator for neuroblastoma. Future studies to determine how TF affects the progression and outcome of neuroblastoma, as well as to investigate its potential role as a therapeutic target, are required.

Immunohistochemical analysis of tissue factor expression in gastric carcinoma: correlations with prognosis and survival

OBJECTIVE

to study the expression of the tissue factor (TF) and its correlation with prognosis and survival in patients with gastric carcinoma.

METHODS

we measured the immunohistochemical expression of TF in 50 specimens of gastric adenocarcinomas from patients submitted to curative surgery. We then compared the intensity of its expression with clinical and pathological data, TNM staging, prognostic factors and survival.

RESULTS

all tumors displayed TF expression; the intensity of TF expression was not associated with TNM stage, clinical or pathological variables or general survival.

CONCLUSION

TF has a high expression in gastric carcinoma, but that it is not useful as a prognostic marker.

Androgen receptor dampens tissue factor expression via nuclear factor-κB and early growth response protein 1

Essentials Androgen deprivation increases the rate of venous thromboembolism in prostate cancer patients. We characterized androgen receptor-mediated tissue factor regulation in prostate epithelial cells. Androgen receptor is dampening tissue factor expression in prostate epithelial cells. Androgen deprivation could enhance tissue factor expression and raise venous thromboembolism rates.

SUMMARY

Background Prostate cancer is one of the leading causes of cancer death in men. Advanced prostate cancer is usually treated by androgen deprivation therapy (ADT), which is aimed at reducing circulating testosterone levels to reduce cancer growth. There is growing evidence that ADT can increase the rate of venous thromboembolism (VTE) in prostate cancer patients. The tissue factor (TF) gene is one of the most important mediators of coagulation and VTE, but, so far, there are limited data on androgen receptor (AR)-mediated TF gene expression. Objectives To characterize AR-mediated TF regulation in vitro and in vivo. Methods We used the androgen-dependent prostate cancer cell lines LNCaP and MyC-CaP to test whether TF expression is regulated by AR. Furthermore, we cloned the TF gene promoter into a luciferase reporter vector to identify the transcription factor-binding sites that mediate TF regulation downstream of AR. Finally, we used castration experiments in mice to characterize AR-mediated TF regulation in vivo. Results TF is directly regulated by AR. In LNCaP cells, nuclear factor-κB signaling and EGR1 mediate TF expression. By using castration experiments in mice, we could detect upregulation of TF and early growth response protein 1 mRNA and protein expression in prostate epithelial cells. Conclusion AR is crucial for dampening TF expression, which could be important for increased TF expression and TF-positive microvesicle release in androgen-deprived prostate cancer patients.

Therapeutic Antibody-Like Immunoconjugates against Tissue Factor with the Potential to Treat Angiogenesis-Dependent as Well as Macrophage-Associated Human Diseases

Accumulating evidence suggests that tissue factor (TF) is selectively expressed in pathological angiogenesis-dependent as well as macrophage-associated human diseases. Pathological angiogenesis, the formation of neovasculature, is involved in many clinically significant human diseases, notably cancer, age-related macular degeneration (AMD), endometriosis and rheumatoid arthritis (RA). Macrophage is involved in the progression of a variety of human diseases, such as atherosclerosis and viral infections (human immunodeficiency virus, HIV and Ebola). It is well documented that TF is selectively expressed on angiogenic vascular endothelial cells (VECs) in these pathological angiogenesis-dependent human diseases and on disease-associated macrophages. Under physiology condition, TF is not expressed by quiescent VECs and monocytes but is solely restricted on some cells (such as pericytes) that are located outside of blood circulation and the inner layer of blood vessel walls. Here, we summarize TF expression on angiogenic VECs, macrophages and other diseased cell types in these human diseases. In cancer, for example, the cancer cells also overexpress TF in solid cancers and leukemia. Moreover, our group recently reported that TF is also expressed by cancer-initiating stem cells (CSCs) and can serve as a novel oncotarget for eradication of CSCs without drug resistance. Furthermore, we review and discuss two generations of TF-targeting therapeutic antibody-like immunoconjugates (ICON and L-ICON1) and antibody-drug conjugates that are currently being tested in preclinical and clinical studies for the treatment of some of these human diseases. If efficacy and safety are proven in current and future clinical trials, TF-targeting immunoconjugates may provide novel therapeutic approaches with potential to broadly impact the treatment regimen of these significant angiogenesis-dependent, as well as macrophage-associated, human diseases.

Crosstalk between cancer and haemostasis

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 TFbearing 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.

Autoantibodies against the cell surface-associated chaperone GRP78 stimulate tumor growth via tissue factor

Tumor cells display on their surface several molecular chaperones that normally reside in the endoplasmic reticulum. Because this display is unique to cancer cells, these chaperones are attractive targets for drug development. Previous epitope-mapping of autoantibodies (AutoAbs) from prostate cancer patients identified the 78-kDa glucose-regulated protein (GRP78) as one such target. Although we previously showed that anti-GRP78 AutoAbs increase tissue factor (TF) procoagulant activity on the surface of tumor cells, the direct effect of TF activation on tumor growth was not examined. In this study, we explore the interplay between the AutoAbs against cell surface-associated GRP78, TF expression/activity, and prostate cancer progression. First, we show that tumor GRP78 expression correlates with disease stage and that anti-GRP78 AutoAb levels parallel prostate-specific antigen concentrations in patient-derived serum samples. Second, we demonstrate that these anti-GRP78 AutoAbs target cell-surface GRP78, activating the unfolded protein response and inducing tumor cell proliferation through a TF-dependent mechanism, a specific effect reversed by neutralization or immunodepletion of the AutoAb pool. Finally, these AutoAbs enhance tumor growth in mice bearing human prostate cancer xenografts, and heparin derivatives specifically abrogate this effect by blocking AutoAb binding to cell-surface GRP78 and decreasing TF expression/activity. Together, these results establish a molecular mechanism in which AutoAbs against cell-surface GRP78 drive TF-mediated tumor progression in an experimental model of prostate cancer. Heparin derivatives counteract this mechanism and, as such, represent potentially appealing compounds to be evaluated in well-designed translational clinical trials.

Role of the Coagulation System in Genitourinary Cancers: Review

Tumor progression is associated with aberrant hemostasis, and patients with malignant diseases have an elevated risk of developing thrombosis. A crosstalk among the vascular endothelium, components of the coagulation cascade, and cancer cells transforms the intravascular milieu to a prothrombotic, proinflammatory, and cell-adhesive state. We review the existing evidence on activation of the coagulation system and its implication in genitourinary malignancies and discuss the potential therapeutic benefit of antithrombotic agents. A literature review was performed searching the Medline database and the Cochrane Library for original articles and reviews. A second search identified studies reporting on oncological benefit of anticoagulants in genitourinary cancer. An elevated expression of procoagulatory tissue factor on tumor cells and tumor-derived microparticles seems to stimulate cancer development and progression. Several components of the hemostatic system, including D-dimers, von Willebrand Factor, thrombin, fibrin-/ogen, soluble P-selectin, and prothrombin fragments 1 + 2 were either overexpressed or overactive in genitourinary cancers. Hypercoagulation was in general associated with a poorer prognosis. Experimental models and small trials in humans showed reduced cancer progression after treatment with anticoagulants. Main limitations of these studies were heterogeneous experimental methodology, small patient numbers, and a lack of prospective validation. In conclusion, experimental and clinical evidence suggests procoagulatory activity of genitourinary neoplasms, particularly in prostate, bladder and kidney cancer. This may promote the risk of vascular thrombosis but also metastatic progression. Clinical studies linked elevated biomarkers of hemostasis with poor prognosis in patients with genitourinary cancers. Thus, anticoagulation may have a therapeutic role beyond prevention of thromboembolism.

Tissue factor associates with survival and regulates tumour progression in osteosarcoma

Osteosarcoma is the most common primary malignant bone tumour. Patients often develop lung metastasis and have a poor prognosis despite extensive chemotherapy and surgical resections. Tissue Factor is associated with poor clinical outcome in a wide range of cancer types, and promotes angiogenesis and metastasis. The role of Tissue Factor in OS tumourigenesis is unknown. Fifty-three osteosarcoma pre-treatment biopsies and four osteosarcoma cell lines were evaluated for Tissue Factor expression, and a possible association with clinical parameters was investigated. Tissue Factor function was inhibited in an osteosarcoma cell line (143B) by shRNA knockdown or specific antibodies, and pro-tumourigenic gene expression, proliferation, matrigel invasion and transwell migration was examined. 143B cells were implanted in mice in the presence of Tissue Factor-blocking antibodies, and tumour volume, micro-vessel density and metastases in the lung were evaluated. Tissue Factor was highly expressed in 73.6 % of osteosarcoma biopsies, and expression associated significantly with disease-free survival. Tissue Factor was expressed in all four investigated cell lines. Tissue Factor was knocked down in 143B cells, which led to reduced expression of IL-8, CXCL-1, SNAIL and MMP2, but not MMP9. Tissue Factor knockdown or inhibition with antibodies reduced matrigel invasion. Tissue Factor antibodies limited 143B tumour growth in vivo, and resulted in decreased intra-tumoural micro-vessel density. Furthermore, lung metastasis from the primary tumour was significantly reduced. Thus, Tissue Factor expression in osteosarcoma reduces metastasis-free survival in patients, and increases pro-tumourigenic behaviour both in vitro and in vivo.

Assessing the carcinogenic potential of low-dose exposures to chemical mixtures in the environment: focus on the cancer hallmark of tumor angiogenesis

One of the important 'hallmarks' of cancer is angiogenesis, which is the process of formation of new blood vessels that are necessary for tumor expansion, invasion and metastasis. Under normal physiological conditions, angiogenesis is well balanced and controlled by endogenous proangiogenic factors and antiangiogenic factors. However, factors produced by cancer cells, cancer stem cells and other cell types in the tumor stroma can disrupt the balance so that the tumor microenvironment favors tumor angiogenesis. These factors include vascular endothelial growth factor, endothelial tissue factor and other membrane bound receptors that mediate multiple intracellular signaling pathways that contribute to tumor angiogenesis. Though environmental exposures to certain chemicals have been found to initiate and promote tumor development, the role of these exposures (particularly to low doses of multiple substances), is largely unknown in relation to tumor angiogenesis. This review summarizes the evidence of the role of environmental chemical bioactivity and exposure in tumor angiogenesis and carcinogenesis. We identify a number of ubiquitous (prototypical) chemicals with disruptive potential that may warrant further investigation given their selectivity for high-throughput screening assay targets associated with proangiogenic pathways. We also consider the cross-hallmark relationships of a number of important angiogenic pathway targets with other cancer hallmarks and we make recommendations for future research. Understanding of the role of low-dose exposure of chemicals with disruptive potential could help us refine our approach to cancer risk assessment, and may ultimately aid in preventing cancer by reducing or eliminating exposures to synergistic mixtures of chemicals with carcinogenic potential.

Prostate cancer: beware of disseminated intravascular coagulation

Disseminated intravascular coagulation (DIC) is a pathological systemic condition resulting from aberrant activation of the coagulation system. It is characterised by the release and activation of procoagulants into the blood, with an associated consumption coagulopathy. Its association with solid and haematological malignancies is well described in literature. This case describes an elderly man, known to have prostate cancer, who following transurethral resection of the prostate developed DIC with haematuria, spontaneous ecchymoses and mucosal bleeding. Subsequent investigations revealed a prostate-specific antigen (PSA) >1000 µg/L, and staging CT showed multiple sclerotic metastatic lesions affecting the thoracic and lumbar vertebra, as well as infiltration into his left femur. Coagulation normalised with blood products and vitamin K within 1 week, and the patient responded to antiandrogen therapy with a reduction in pain and PSA on discharge.

Advanced research on vasculogenic mimicry in cancer

Vasculogenic mimicry (VM) is a brand-new tumour vascular paradigm independent of angiogenesis that describes the specific capacity of aggressive cancer cells to form vessel-like networks that provide adequate blood supply for tumour growth. A variety of molecule mechanisms and signal pathways participate in VM induction. Additionally, cancer stem cell and epithelial-mesenchymal transitions are also shown to be implicated in VM formation. As a unique perfusion way, VM is associated with tumour invasion, metastasis and poor cancer patient prognosis. Due to VM's important effects on tumour progression, more VM-related strategies are being utilized for anticancer treatment. Here, with regard to the above aspects, we make a review of advanced research on VM in cancer.

Increased tissue factor expression is an independent predictor of mortality in clear cell carcinoma of the kidney

PURPOSE

Increased expression of tissue factor (TF), a primary initiator of the extrinsic coagulation pathway, has been associated with a worse prognosis in a variety of solid tumors. We report for the first time the correlation of the immunohistochemical expression of tissue factor with clinical and pathological outcomes in clear cell carcinomas of the kidney.

MATERIALS AND METHODS

immunohistochemical expression of tissue factor was evaluated in 58 paraffin-embedded samples of clear cell carcinomas of the kidney treated at the same university hospital, that was correlated with clinical and pathological variables and with overall survival.

RESULTS

high intensity tissue factor expression (TF area > 10 µ m2) was observed in 22.4% of the tumors (13 patients), and was an important predictor of overall mortality, both in univariate and multivariate analysis (p < 0.05). Median overall survival for both groups was 66 months; 78.2 months for patients in the group of lower TF expression and 27.5 months for patients in the group of higher TF expression (log rank p < 0.001). The hazard ratio for mortality was 9.7 (CI 3.7-25.6) for tumors with increased TF expression.

CONCLUSIONS

Increased immunohistochemical expression of TF was an important independent predictor of mortality in a contemporary cohort of patients with clear cell carcinoma of the kidney. Further studies are necessary to define the role of TF in clinical practice.

Symptomatic and incidental venous thromboembolic disease are both associated with mortality in patients with prostate cancer

Introduction

The association between malignancy and venous thromboembolic disease (VTE) is well established. The independent impact of VTE, both symptomatic and incidental, on survival in patients with prostate cancer is not known. We conducted a retrospective cohort study to evaluate the effect of VTE of survival in prostate cancer.

Methods

Data regarding clinical characteristics, treatment and outcomes of 453 consecutive prostate cancer patients were collected. Fisher exact (categorical variables) and t-test (continuous variables) were utilized to test associations with VTE and mortality. Survival was estimated using the Kaplan Meier method. A Cox regression model was used to model the mortality hazard ratio (HR).

Results

At diagnosis, 358 (83%) patients had early stage disease, 43 (10%) had locally advanced disease and 32 (7%) had metastatic disease. During the follow up period, 122 (27%) patients died and 41 (9%) developed VTE (33 deep vein thrombosis, 5 pulmonary embolism, and 3 patients with both DVT and PE). Twenty-five VTE events were symptomatic and 16 were incidentally diagnosed on CT scans obtained for other reasons. VTE was associated with increased mortality [HR 6.89 (4.29–11.08), p<0.001] in a multivariable analysis adjusted for cancer stage, performance status, treatments and co-morbidities. There was no difference in survival between patients who had symptomatic and incidental VTE.

Conclusion

Venous thromboembolic disease, both symptomatic and incidental, is a predictor of poor survival in patients with prostate cancer, especially those with advanced disease. Further studies are needed to evaluate the benefit of prophylactic and therapeutic anticoagulation in this population.

Decreased mitochondrial SIRT3 expression is a potential molecular biomarker associated with poor outcome in breast cancer

SIRT3 is a genomically expressed, mitochondrial localized tumor suppressor protein where it directs multiple metabolic processes by deacetylating downstream protein substrates. Genetic deletion of Sirt3 in mice leads to the spontaneous development of mammary tumors starting at 1 year, and decreased SIRT3 messenger RNA has been observed in several human tumors including breast malignancies. In this investigation, we assessed SIRT3 expression in human breast cancer tissue microarray and examined the relationship between SIRT3 expression and outcome in patients with breast cancer. SIRT3 protein expression is significantly lower in neoplastic compared with normal breast epithelium, including normal epithelium adjacent to tumors. Patients with breast cancer in the lowest quartile of SIRT3 expression had a significantly shorter locoregional relapse-free survival (hazard ratio, 0.53 [0.47-0.61]; log-rank P = 0). Notably, low SIRT3 expression was associated with reduced locoregional relapse-free survival in all breast cancer subtypes analyzed, including ER+, ER-, HER2+, and basal subtypes (hazard ratios, 0.44-0.65; log-rank P = 0-.0019). These results highlight the importance of the SIRT3 as a tumor suppressor protein in breast cancer and suggest that SIRT3 may be a potential molecular biomarker to identify high-risk patients across all molecular subtypes of breast cancer.

Expression of tissue factor and tissue factor pathway inhibitor in microparticles and subcellular fractions of normal and malignant prostate cell lines

The association between cancer and thrombogenesis has been recognized since 1865, and tissue factor (TF) is important at various stages in the natural history of the disease. It is involved in cancer angiogenesis, growth and metastasis. TF pathway inhibitor (TFPI), being the major physiological regulator of the TF-dependent coagulation pathway, is also important in establishing net procoagulant potential. In this study, we determine TF and TFPI levels in three prostate epithelial cell lines, one of normal and two of malignant origin. Cells were grown in standard maintenance conditions and harvested at more than 90% confluence. These were fractionated into cytosol, membrane and nuclei for analysis. Microparticles secreted into the culture medium were also analysed. TF and TFPI levels were determined using an ELISA. TF expression in these cells was also visualized using immunocytochemistry. There was absence of TF and TFPI in nuclei of all cell lines. TF expression was higher in subcellular fractions and microparticles of normal prostate cells than cancer cells. In contrast, levels of TFPI (structurally resembling a secreted, rather than transmembrane protein) in microparticles of normal prostate cells were much lower than tumour cells. In conclusion, the activity of prostate cancer cells themselves is unlikely to be the source of hypercoagulability in patients, but might precipitate chains of events that would produce such an effect.

Severe bleeding tendency caused by a rare complication of excessive fibrinolysis with disseminated intravascular coagulation in a 51-year-old Japanese man with prostate cancer: a case report

Introduction

Disseminated intravascular coagulation causes thrombotic tendency leading to multiple organ failure and occurs in a wide variety of diseases including malignancy. Disseminated intravascular coagulation is a latent complication in people with prostate cancer.

Case presentation

A 51-year-old Japanese man with advanced castration-resistant prostate cancer was admitted to our hospital because of extensive purpura and severe anemia. Prolonged plasma coagulation time, hypofibrinogenemia and normal platelet count suggested that a decrease in fibrinogen induced a bleeding tendency causing purpura. However, elevated plasma levels of thrombin-antithrombin complex, fibrin and/or fibrinogen degradation products and D-dimers, with positive fibrin monomer test, manifested disseminated intravascular coagulation and subsequent fibrinolysis. Plasma levels of thrombin-antithrombin complex, fibrin and/or fibrinogen degradation products and D-dimers decreased after administration of low-molecular-weight heparin. However, low fibrinogen and α₂-antiplasmin levels were not improved and plasmin-antiplasmin complex did not decrease, which revealed excessive fibrinolysis complicated with disseminated intravascular coagulation. We suspected that prostate cancer cell-derived urokinase-type plasminogen activator caused excessive fibrinolysis. Administration of tranexamic acid for fibrinogenolysis was added together with high-dose anti-androgen therapy (fosfestrol) for prostate cancer. Thereafter, prostate-specific antigen and plasmin-antiplasmin complex decreased, followed by normalized fibrinogen and α₂-antiplasmin levels, and the patient eventually recovered from the bleeding tendency. Immunohistochemical staining of the biopsied prostate tissue exhibited that the prostate cancer cells produced tissue factor, the coagulation initiator, and urokinase-type plasminogen activator.

Conclusion

This patient with rare complications of disseminated intravascular coagulation and excessive fibrinolysis is a warning case of potential coagulation disorder onset in patients with prostate cancer. We propose that combined administration of tranexamic acid and low-molecular-weight heparin together with high-dose anti-androgen therapy is a useful therapeutic option for patients with this complicated coagulation disorder.

An observational study of plasma vascular endothelial growth factors (VEGF) A and D expression in non-localized prostate cancer

BACKGROUND

The aim of the study was to measure plasma levels of the vascular endothelial growth factors (VEGF) A and D in serially collected blood specimens from non-localized prostate cancer (PCa) subjects.

METHODS

Plasma VEGF A and D levels were measured in two serial specimens 3-6 months apart in two groups of non-localized stage PCa patients. Group 1 was comprised of patients with biochemical relapse after localized PCa treatments and/or patients with clinically metastatic hormone-sensitive stage PCa prior to receiving hormonal therapy. Group 2 included patients failing hormonal therapy for non-localized hormone-sensitive stage PCa. VEGF A and D levels were compared within each cancer group between the two time-points using the Wilcoxon Rank Sum test.

RESULTS

At the first time-point in Group 1 (n = 46), median VEGF-A and D levels were measured at 5.2 (pg/ml) (range = 0-97) and 319 (range = 172-780) (pg/ml). For Group 2 (n = 34) VEGF-A level was 9.6 pg/ml (range = 0-78) and VEGF-D level was 377 pg/ml (range = 243-989) for the first measurement. Median time-period for the serial second specimen was 189 days in Group 1 and 84 days in Group 2. At the second time-point, in Group 1, VEGF-A levels were 0.0 pg/ml (P = 0.0002) while VEGF-D increased to 349 pg/ml (P = 0.002). For Group 2 patients at the second time-point, median VEGF-A was 0.0 pg/ml (P = 1.0) and VEGF-D was measured at 442 pg/ml (P = 0.008).

CONCLUSIONS

Higher plasma VEGF-D than VEGF-A expression in advanced PCa stages suggests a greater role for VEGF-D dependent lymph angiogenesis in advanced stage PCa, which needs further evaluation.

Tissue factor expression in the metaplasia-adenoma-carcinoma sequence of gastric cancer in a European population

BACKGROUND

Tissue factor (TF), which has a role in normal tissue haemostasis, was reported to be aberrantly expressed, associated with higher microvascular density and a poor prognosis in intestinal-type gastric adenocarcinoma in the Japanese population. This is the first study to look at the relationship of TF and the metaplasia-adenoma-carcinoma sequence (MACS) of gastric cancer in a European population.

METHODS

The expression of TF was examined immunohistochemically in 191 gastric tissue samples: (13: normal; 18: intestinal metaplasia; 160: gastric adenocarcinoma) from the European population.

RESULTS

TF was not expressed in normal gastric mucosal cells. A strong intensity of staining was found in intestinal metaplasia cells but in 2 of 18 samples. TF expression increased with advancing stage of gastric cancer (P<0.0001, Jonckheere's test for ordered medians). Stage 3-4 gastric cancers preferentially expressed TF (34%, P=0.04). In comparison with the Japanese study, TF was not expressed at a higher level in intestinal vs diffuse-type gastric cancers and expression had 'no prognostic' significance.

CONCLUSION

TF may be involved in tumour progression along the MACS of gastric cancer in the European population and is shown to start in precancerous lesions. However, clinical features may differ due to differences in biological features in the two populations, as reflected by differences in TF expression profile.

The relationship between tissue factor and cancer progression: insights from bench and bedside

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.

Pim1 kinase is required to maintain tumorigenicity in MYC-expressing prostate cancer cells

PIM1 kinase and MYC are commonly co-expressed in human prostate cancer and synergize to induce rapidly progressing prostate cancer in mouse models. Deficiency of the Pim kinase genes is well tolerated in vivo, suggesting that PIM1 inhibition might offer an attractive therapeutic modality for prostate cancer, particularly for MYC-expressing tumors. Here we examine the molecular consequences of Pim1 and MYC over-expression in the prostate as well as the effects of depleting Pim1 in prostate carcinoma cells with high levels of MYC. Over-expression of Pim1 in the mouse prostate induces several pro-tumorigenic genetic programs including cell cycle genes and Myc-regulated genes prior to the induction of any discernible pathology. Pim1 depletion by RNA interference in mouse and human prostate cancer cells decreased cellular proliferation, survival, Erk signaling, and tumorigenicity even when MYC levels were not significantly altered. These results indicate that PIM1 may be necessary to maintain tumorigenicity, and further support efforts aimed at developing PIM1 inhibitors for prostate cancer therapy.

Arterial and venous thrombosis in cancer patients

The most frequent ultimate cause of death is myocardial arrest. In many cases this is due to myocardial hypoxia, generally arising from failure of the coronary macro- and microcirculation to deliver enough oxygenated red cells to the cardiomyocytes. The principle reason for this is occlusive thrombosis, either by isolated circulating thrombi, or by rupture of upstream plaque. However, an additionally serious pathology causing potentially fatal stress to the heart is extra-cardiac disease, such as pulmonary hypertension. A primary cause of the latter is pulmonary embolus, considered to be a venous thromboembolism. Whilst the thrombotic scenario has for decades been the dominating paradigm in cardiovascular disease, these issues have, until recently, been infrequently considered in cancer. However, there is now a developing view that cancer is also a thrombotic disease, and notably a disease predominantly of the venous circulation, manifesting as deep vein thrombosis and pulmonary embolism. Indeed, for many, a venous thromboembolism is one of the first symptoms of a developing cancer. Furthermore, many of the standard chemotherapies in cancer are prothrombotic. Accordingly, thromboprophylaxis in cancer with heparins or oral anticoagulation (such as Warfarin), especially in high risk groups (such as those who are immobile and on high dose chemotherapy), may be an important therapy. The objective of this communication is to summarise current views on the epidemiology and pathophysiology of arterial and venous thrombosis in cancer.

Role of monocyte-lineage cells in prostate cancer cell invasion and tissue factor expression

BACKGROUND

Tissue factor (TF) is a cell surface glycoprotein intricately related to blood coagulation and inflammation. This study was performed to investigate the role of monocyte-lineage cells in prostate cancer cell TF expression and cell invasion.

METHODS

Prostate cancer cell invasion was tested with and without added peripheral blood monocytes or human monocyte-lineage cell lines. TF neutralizing antibodies were used to determine the TF requirement for prostate cancer cell invasion activity. Immunohistochemistry was performed to identify prostate tissue CD68 positive monocyte-derived cells and prostate epithelial TF expression.

RESULTS

Co-culture of PC-3, DU145, and LNCaP cells with isolated human monocytes significantly stimulated prostate cancer cell invasion activity. TF expression was greater in highly invasive prostate cancer cells and was induced in PC-3, DU145, and LNCaP cells by co-culture with U-937 cells, but not with THP-1 cells. TF neutralizing antibodies inhibited PC-3 cell invasion in co-cultures with monocyte-lineage U-937 or THP-1 cells. Prostate cancer tissues contained more CD68 positive cells in the stroma and epithelium (145 ± 53/mm(2)) than benign prostate (108 ± 31/mm(2)). Samples from advanced stage prostate cancer tended to contain more CD68 positive cells when compared with lower stage lesions. Prostatic adenocarcinoma demonstrated significantly increased TF expression compared with benign prostatic epithelium.

CONCLUSIONS

This study shows that co-culture with monocyte-lineage cells induced prostate cancer cell invasion activity. PC-3 invasion and TF expression was induced in co-culture with U-937 cells and partially inhibited with TF neutralizing antibodies.

Binding of anti-GRP78 autoantibodies to cell surface GRP78 increases tissue factor procoagulant activity via the release of calcium from endoplasmic reticulum stores

The increased risk of venous thromboembolism in cancer patients has been attributed to enhanced tissue factor (TF) procoagulant activity (PCA) on the surface of cancer cells. Recent studies have shown that TF PCA can be modulated by GRP78, an endoplasmic reticulum (ER)-resident molecular chaperone. In this study, we investigated the role of cell surface GRP78 in modulating TF PCA in several human cancer cell lines. Although both GRP78 and TF are present on the cell surface of cancer cells, there was no evidence of a stable interaction between recombinant human GRP78 and TF, nor was there any effect of exogenously added recombinant GRP78 on cell surface TF PCA. Treatment of cells with the ER stress-inducing agent thapsigargin, an inhibitor of the sarco(endo)plasmic reticulum Ca(2+) pump that causes Ca(2+) efflux from ER stores, increased cytosolic [Ca(2+)] and induced TF PCA. Consistent with these findings, anti-GRP78 autoantibodies that were isolated from the serum of patients with prostate cancer and bind to a specific N-terminal epitope (Leu(98)-Leu(115)) on cell surface GRP78, caused a dose-dependent increase in cytosolic [Ca(2+)] and enhanced TF PCA. The ability to interfere with cell surface GRP78 binding, block phospholipase C activity, sequester ER Ca(2+), or prevent plasma membrane phosphatidylserine exposure resulted in a significant decrease in the TF PCA induced by anti-GRP78 autoantibodies. Taken together, these findings provide evidence that engagement of the anti-GRP78 autoantibodies with cell surface GRP78 increases TF PCA through a mechanism that involves the release of Ca(2+) from ER stores. Furthermore, blocking GRP78 signaling on the surface of cancer cells attenuates TF PCA and has the potential to reduce the risk of cancer-related venous thromboembolism.

Mapping pro- and antiangiogenic factors on the surface of prostasomes of normal and malignant cell origin

BACKGROUND

Angiogenesis is the formation of new blood vessels by capillary sprouting from pre-existing vessels. Tumor growth is angiogenesis-dependent and the formation of new blood vessels is associated with the increased expression of angiogenic factors. Prostasomes are secretory granules produced, stored and released by the glandular epithelial cells of the prostate. We investigated the expression of selected angiogenic and anti-angiogenic factors on the surface of prostasomes of different origins as well as the direct effect of prostasomes on angiogenesis.

METHODS

VEGF, endothelin-1, endostatin, and thrombospondin-1 were determined on prostasomes from seminal fluid and human prostate cancer cell lines (DU145,PC-3,LNCaP) using different immunochemical techniques. Human dermal microvascular endothelial cells were incubated with seminal and DU145 cell-prostasomes and with radioactive thymidine. The effect of prostasomes on angiogenesis was judged by measuring the uptake of labeled thymidine. The presence of any deleterious effects of prostasomes on the endothelial cells was investigated using thymidine assay and confocal laser microscopy.

RESULTS

VEGF and endothelin-1 were determined on malignant cell-prostasomes (no difference between cell lines) but not determined on seminal prostasomes. The same applies for the expression of endostatin but with much higher expression on malignant cell-prostasomes with obvious differences between them. Seminal and DU145 cell-prostasomes were found to have anti-angiogenic effect which was more expressed by DU145 cell-prostasomes. No deleterious effect of prostasomes on endothelial function was detected using either thymidine assay or microscopy.

CONCLUSIONS

Prostasomes contain pro- and anti-angiogenic factors that function to counteract each other unless the impact from one side exceeds the other to bring about dysequilibrium.

Immunolocalisation of tissue factor in esophageal cancer is correlated with intratumoral angiogenesis and prognosis of the patient

It has been demonstrated that tissue factor (TF) may be involved in the tumor-derived procoagulatory status and angiogenic modulation in certain solid tumors. In the present study, we examined immunohistochemical localisation of TF in esophageal squamous cell carcinomas (ESCC) from 103 patients. TF immunopositivity was found in 91.3% of all tumor sections, while normal esophageal tissues were immunonegative. Patients were divided into a low TF immunoreactivity group (9 cases of negative and 48 cases of weak positive) and a high TF immunoreactivity group (35 cases of moderate positive and 11 cases of strong positive). TF immunoreactivity was significantly correlated to the presence of distant metastasis (P=0.0014), while it was not correlated to patient's gender, age, tumor size, depth of tumor invasion or lymph node metastasis. Survival analysis revealed that the overall survival rate in the patients that had high TF immunoreactivity was significantly poorer than those with low TF immunoreactivity (P=0.0094). Univariate analysis demonstrated that tumor size (P=0.0095), depth of tumor invasion (P=0.0050), lymph node metastasis (P=0.0045) and distant metastasis (P<0.0001) were effective predictors of prognosis in patients. However, only distant metastasis could independently predict patients' outcomes by the analysis of multivariate proportional hazards regression (P=0.0043). Furthermore, the intratumoral microvessel density (MVD), evaluated by CD34 immunolabeling, indicated that MVD was positively correlated to the TF immunoreactivity (P=0.0056). It is concluded that TF immunopositivity in ESCC tissues is strongly correlated to the intratumoral angiogenesis and to poor patient prognosis.

Molecular regulation of vasculogenic mimicry in tumors and potential tumor-target therapy

“Vasculogenic mimicry (VM)”, is a term that describes the unique ability of highly aggressive tumor cells to express a multipotent, stem cell-like phenotype, and form a pattern of vasculogenic-like networks in three-dimensional culture. As an angiogenesis-independent pathway, VM and/or periodic acid-schiff-positive patterns are associated with poor prognosis in tumor patients. Moreover, VM is resistant to angiogenesis inhibitors. Here, we will review the advances in research on biochemical and molecular signaling pathways of VM in tumors and on potential anti-VM therapy strategy.

Erythropoiesis stimulating agents, thrombosis and cancer

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.

Tissue factor in cardiovascular disease pathophysiology and pharmacological intervention

Tissue factor (TF) is the major trigger of the coagulation cascade and thereby crucially involved in the maintenance of vascular hemostasis. By binding factor VIIa, the resulting TF:VIIa complex activates the coagulation factors IX and X ultimately leading to fibrin and clot formation. In the vessel wall, TF expression and activity is detectable in vascular smooth muscle cells and fibroblasts and, at a much lower level, in endothelial cells and can be induced by various stimuli including cytokines. In addition, TF is found in the bloodstream in circulating cells such as monocytes, in TF containing microparticles, and as a soluble splicing isoform. Besides its well-known extracellular role as a trigger of coagulation, TF also functions as a transmembrane receptor, and TF-dependent intracellular signaling events regulate the expression of genes involved in cellular responses such as proliferation and migration. TF indeed appears to be involved in the pathogenesis of neointima formation and tumor growth, and increased levels of TF have been detected in patients with cardiovascular risk factors or coronary artery disease as well as in those with cancer. Therefore, pharmacological or genetic inhibition of TF may be an attractive target for the treatment of cardiovascular disease and cancer. Different strategies for inhibition of TF have been developed such as inhibition of TF synthesis and blockade of TF action. Clinical applications of such strategies need to be tested in appropriate trials, in particular for evaluating the advantages of targeted versus systemic delivery of the inhibitors.

Tissue factor in tumour progression

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.

Efficient suppression of tissue factor synthesis using antisense oligonucleotides selected by an enhanced strategy for evaluation of structural characteristics

Selection of optimal antisense constructs is still a problem. Among a huge number of antisense oligonucleotides (AS-ONs) only a small piece show inhibitory efficacy. We want to develop an enhanced strategy for specific selection of effective AS-ONs based on prediction of secondary structure of the target messenger RNA (mRNA) and analysis of thermodynamic properties of the mRNA/AS-ON hybrid. Numerous AS-ONs targeted on human tissue factor (TF) mRNA were investigated to evaluate the relevance of different thermodynamic and structural properties on inhibitory efficacy. Cell viability, TF protein and TF mRNA were determined after transfection of bladder cancer cell line J82. Inhibitory efficacy was related to GC content, target region within the TF mRNA and stability of the mRNA/AS-ON hybrid or affinity of the AS-ON to the target mRNA. We found effective AS-ONs targeted on translated region or 3'-untranslated region of TF RNA. We also detected a great correlation between inhibitory efficacy and GC content as well as stability of the mRNA/AS-ON hybrid.

Expression of tissue factor in prostate cancer correlates with malignant phenotype

Tissue factor (TF), apart from its established role in hemostasis, has been implicated in promoting angiogenesis and metastasis in a wide array of tumors including prostate cancer. Expression of TF was evaluated in freshly-resected prostate specimens obtained from patients with localized (n=9) and androgen ablated (n=6) disease using real-time reverse transcription-polymerase chain reaction and Western blot analysis. TF was detected in all specimens in both stages of the disease. We further analyzed for correlations between TF expression and those of several angiogenic growth factors and their receptors. TF RNA expression correlated significantly with expression of vascular endothelial growth factor-A in these specimens (s=0.621, P=0.013). Eighty-one prostate specimens from patients with benign prostatic hyperplasia (n=27), localized prostate cancer (ES, n=32), and advanced disease (n=22) were also evaluated using immunohistochemistry and findings were correlated with clinical parameters. TF expression was detected on epithelial cells of the malignant glands. Furthermore, its expression levels correlated significantly with Gleason score (s=0.58, P=0.0001) and with the stage of the disease (s=0.441, P=0.0001) in these specimens. These data support the role of TF in angiogenesis and disease progression.

Vaccination against prostate cancer using a live tissue factor deficient cell line in Lobund-Wistar rats

Reducing expression of the tissue factor gene in prostate adenocarcinoma cells (PAIII) results in a cell line that, in vivo, mimics the growth of wildtype (wt) PAIII. However, instead of continuing to grow and metastasize as wt PAIII tumors do, tissue factor deficient PAIII (TFD PAIII) masses spontaneously regress after several weeks. Although whole cell vaccines are typically inactivated prior to administration to prevent proliferation within the host, numerous studies have suggested that exposure to live, attenuated, whole tumor cells, and the extracellular microenvironment they recruit, increases immunotherapeutic potential. Here, we provide support for this notion, and a strategy through which to implement it, by demonstrating that subcutaneous vaccinations with the TFD PAIII protect the Lobund-Wistar rat against subsequent wt PAIII cell challenge. TFD PAIII immunized rats suffered significantly less metastasis of wt PAIII challenge tumors compared to unvaccinated naïve controls rats. These results offer the intriguing possibility that the TFD PAIII vaccine is an effective system for the prevention and, possibly, the treatment of prostate cancer.

CNTO 859, a humanized anti-tissue factor monoclonal antibody, is a potent inhibitor of breast cancer metastasis and tumor growth in xenograft models

Thromboembolic complications are frequently associated with advanced cancer. Interestingly, one of the major initiators of blood coagulation, tissue factor (TF), is reported to be overexpressed in several tumor types and can be found on both tumor cells and tumor vasculature. Although the exact mechanisms have yet to be elucidated, TF expressed on tumor cells can trigger intracellular signaling events through various pathways that can lead to tumor angiogenesis, proliferation, and metastasis. There exists preclinical evidence that disruption of TF dependent signaling can effectively inhibit tumor cell migration, metastasis, and angiogenesis. Here, we report for the first time that an antibody to tissue factor can also prevent tumor growth in vivo. Prophylactic administration of CNTO 859, a humanized anti-human TF antibody, was shown to inhibit experimental lung metastasis of MDA-MB-231 human breast carcinoma cells by over 99% compared to a control antibody. Furthermore, therapeutic doses of CNTO 859 were shown to reduce tumor incidence and growth of orthotopically implanted MDA-MB-231 cells.