Tissue factor expression and prognosis in patients with metastatic prostate cancer

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.

The Tissue Factor Pathway in Cancer: Overview and Role of Heparan Sulfate Proteoglycans

Historically, the only focus on tissue factor (TF) in clinical pathophysiology has been on its function as the initiation of the extrinsic coagulation cascade. This obsolete vessel-wall TF dogma is now being challenged by the findings that TF circulates throughout the body as a soluble form, a cell-associated protein, and a binding microparticle. Furthermore, it has been observed that TF is expressed by various cell types, including T-lymphocytes and platelets, and that certain pathological situations, such as chronic and acute inflammatory states, and cancer, may increase its expression and activity. Transmembrane G protein-coupled protease-activated receptors can be proteolytically cleaved by the TF:FVIIa complex that develops when TF binds to Factor VII (PARs). The TF:FVIIa complex can activate integrins, receptor tyrosine kinases (RTKs), and PARs in addition to PARs. Cancer cells use these signaling pathways to promote cell division, angiogenesis, metastasis, and the maintenance of cancer stem-like cells. Proteoglycans play a crucial role in the biochemical and mechanical properties of the cellular extracellular matrix, where they control cellular behavior via interacting with transmembrane receptors. For TFPI.fXa complexes, heparan sulfate proteoglycans (HSPGs) may serve as the primary receptor for uptake and degradation. The regulation of TF expression, TF signaling mechanisms, their pathogenic effects, and their therapeutic targeting in cancer are all covered in detail here.

Potential of uPAR, αvβ6 Integrin, and Tissue Factor as Targets for Molecular Imaging of Oral Squamous Cell Carcinoma: Evaluation of Nine Targets in Primary Tumors and Metastases by Immunohistochemistry

No clinically approved tumor-specific imaging agents for head and neck cancer are currently available. The identification of biomarkers with a high and homogenous expression in tumor tissue and minimal expression in normal tissue is essential for the development of new molecular imaging targets in head and neck cancer. We investigated the expression of nine imaging targets in both primary tumor and matched metastatic tissue of 41 patients with oral squamous cell carcinoma (OSCC) to assess their potential as targets for molecular imaging. The intensity, proportion, and homogeneity in the tumor and the reaction in neighboring non-cancerous tissue was scored. The intensity and proportion were multiplied to obtain a total immunohistochemical (IHC) score ranging from 0-12. The mean intensity in the tumor tissue and normal epithelium were compared. The expression rate was high for the urokinase-type plasminogen activator receptor (uPAR) (97%), integrin αvβ6 (97%), and tissue factor (86%) with a median total immunostaining score (interquartile range) for primary tumors of 6 (6-9), 12 (12-12), and 6 (2.5-7.5), respectively. For the uPAR and tissue factor, the mean staining intensity score was significantly higher in tumors compared to normal epithelium. The uPAR, integrin αvβ6, and tissue factor are promising imaging targets for OSCC primary tumors, lymph node metastases, and recurrences.

Population pharmacokinetic analysis for tisotumab vedotin in patients with locally advanced and/or metastatic solid tumors

Tisotumab vedotin is an investigational antibody-drug conjugate (ADC) for treatment of solid tumors expressing tissue factor with accelerated approval from the US Food and Drug Administration for treatment of recurrent or metastatic cervical cancer with disease progression during or after chemotherapy. This study describes development of a population pharmacokinetic (PK) model to assess the PK profile of tisotumab vedotin and microtubule-disrupting agent monomethyl auristatin E (MMAE) using data from 399 patients with solid tumors across four phase I/II trials. The ADC-MMAE model describes ADC and MMAE concentrations following intravenous administration of tisotumab vedotin. This four-compartment model comprises a two-compartment ADC model with parallel linear and Michaelis-Menten elimination, a delay compartment, and a one-compartment MMAE model. Nonspecific linear clearance of ADC was 1.42 L/day, central volume of distribution (V_c ) was 3.10 L, and median terminal half-life of ADC was 4.04 days. Apparent clearance of MMAE was 42.8 L/day, and apparent volume of distribution was 2.09 L. Terminal slope of the MMAE concentration-time curve was defined by the delay compartment rate with a half-life of 2.56 days. Patients with higher body weight and lower albumin concentration had faster ADC clearance. Male patients and those with higher body weight and lower albumin concentration had higher V_c . Body weight was the most influential covariate influencing distribution and elimination of ADC and MMAE, thus supporting weight-based dosing of tisotumab vedotin. Presence of antidrug antibodies (detected in 3.3% of patients) did not affect key PK parameters or exposures for ADC and MMAE.

Research Trend of Publications Concerning Antibody-Drug Conjugate in Solid Cancer: A Bibliometric Study

Background: Antibody-drug conjugate (ADC) is a promising therapy for solid cancer that has raised global concern. Although several papers have reviewed the current state of ADCs in different solid cancers, a quantitative analysis of the publications in this field is scarce.

Methods: Publications related to ADC in the field of solid cancer were obtained from the Web of Science Core Collection. Data analyses were performed with VOSviewer 1.6.9, HistCite 2.1, CiteSpace V and R package Bibliometrix.

Results: A total of 3,482 records were obtained in the holistic field and 1,197 in the clinical field. Steady growth in the number of publications was observed. The United States was the leading contributor in this field. Krop IE was the most influential author. The most productive institution was Genentech Inc., while Mem Sloan Kettering Canc Ctr was the most cited one. The most impactful journal was the Journal of Clinical Oncology. A total of 37 burst references and five burst references were identified between 2017–2022 in the holistic and clinical fields, respectively. Keywords analysis indicated that ADCs research mainly involved breast cancer, triple-negative breast cancer, ovarian cancer, small cell lung cancer, prostate cancer, gastric cancer, and urothelial carcinoma. ADC agents including trastuzumab emtansine, trastuzumab deruxtecan, sacituzumab govitecan, enfortumab vedotin, and rovalpituzumab tesirine were highly studied. Targets including HER2, trophoblast cell-surface antigen, mesothelin, delta-like ligand 3, and nectin-4 were the major concerns.

Conclusion: This study analyzed publications concerning ADCs in the field of solid cancer with bibliometric analysis. Further clinical trials of ADCs and designs of the next generation of ADCs are the current focuses of the field. Acquired resistance of ADCs and biomarkers for ADC therapy efficacy monitoring are future concerns.

Selective delivery of clinically approved tubulin binding agents through covalent conjugation to an active targeting moiety

Abstract:

The efficacy and tolerability of tubulin binding agents are hampered by their low specificity for cancer cells, like most clinically used anticancer agents. To improve specificity, tubulin binding agents have been covalently conjugated to agents which target cancer cells to give actively targeted drug conjugates. These conjugates are designed to increase uptake of the drug by cancer cells, while having limited uptake by normal cells thereby improving efficacy and tolerability. Approaches used include attachment to small molecules, polysaccharides, peptides, proteins and antibodies that exploit the overexpression of receptors for these substances. Antibody targeted strategies have been the most successful to date with six such examples having gained clinical approval. Many other conjugate types, especially those targeting the folate receptor, have shown promising efficacy and toxicity profiles in pre-clinical models and in early-stage clinical studies. Presented herein is a discussion of the success or otherwise of the recent strategies used to form these actively targeted conjugates.

Characterization of a novel bispecific antibody targeting tissue factor-positive tumors with T cell engagement

T cell engaging bispecific antibody (TCB) is an effective immunotherapy for cancer treatment. Through co-targeting CD3 and tumor-associated antigen (TAA), TCB can redirect CD3⁺ T cells to eliminate tumor cells regardless of the specificity of T cell receptor. Tissue factor (TF) is a TAA that involved in tumor progression. Here, we designed and characterized a novel TCB targeting TF (TF-TCB) for the treatment of TF-positive tumors. In vitro, robust T cell activation, tumor cell lysis and T cell proliferation were induced by TF-TCB. The tumor cell lysis activity was dependent upon both CD3 and TF binding moieties of the TF-TCB, and was related to TF expression level of tumor cells. In vivo, in both tumor cell/human peripheral blood mononuclear cells (PBMC) co-grafting model and established tumor models with poor T cell infiltration, tumor growth was strongly inhibited by TF-TCB. T cell infiltration into tumors was induced during the treatment. Furthermore, efficacy of TF-TCB was further improved by combination with immune checkpoint inhibitors. For the first time, our results validated the feasibility of using TF as a target for TCB and highlighted the potential for TF-TCB to demonstrate efficacy in solid tumor treatment.

Tissue Factor and Extracellular Vesicles: Activation of Coagulation and Impact on Survival in Cancer

Simple Summary

The tissue factor (TF)-factor VIIa complex is the major physiological initiator of blood coagulation. Tumors express TF and release TF-positive extracellular vesicles (EVs) into the circulation, and this is associated with the activation of coagulation. Circulating levels of EVTF activity may be a useful biomarker to identify patients at risk for thrombosis. Tumor TF and TF-positive EVs are also associated with reduced survival.

Abstract

Tissue factor (TF) is a transmembrane glycoprotein that functions as a receptor for FVII/FVIIa and initiates the extrinsic coagulation pathway. Tumors and cancer cells express TF that can be released in the form of TF positive (TF+) extracellular vesicles (EVs). In this review, we summarize the studies of tumor TF and TF + EVs, and their association with activation of coagulation and survival in cancer patients. We also summarize the role of tumor-derived TF + EVs in venous thrombosis in mouse models. Levels of tumor TF and TF + EVs are associated with venous thromboembolism in pancreatic cancer patients. In addition, levels of EVTF activity are associated with disseminated intravascular coagulation in cancer patients. Furthermore, tumor-derived TF + EVs enhance venous thrombosis in mice. Tumor TF and TF + EVs are also associated with worse survival in cancer patients, particularly in pancreatic cancer patients. These studies indicate that EVTF activity could be used as a biomarker to identify pancreatic cancer patients at risk for venous thrombosis and cancer patients at risk for disseminated intravascular coagulation. EVTF activity may also be a useful prognostic biomarker in cancer patients.

Cancer cell-derived tissue factor-positive extracellular vesicles: biomarkers of thrombosis and survival

PURPOSE OF REVIEW

Tissue factor (TF) is released from cancer cells and tumors in the form of extracellular vesicles (EVs). This review summarizes our current knowledge of the mechanisms of release of TF-positive EVs (TF+EVs) from cancer cells and the effect of these TF+EVs on cultured endothelial cells. In addition, we will summarize the contribution of TF+EVs to thrombosis in mice, and the association between plasma EVTF activity and venous thrombosis as well as survival of cancer patients.

RECENT FINDINGS

The release of TF+EVs from cancer cells is regulated by multiple factors, including hypoxia, epithelial-mesenchymal transition, and various intracellular signaling pathways. Cancer cell-derived, TF+EVs confer procoagulant activity to endothelial cells and induce the expression of adhesion proteins and IL-8. In addition, they contribute to thrombosis by directly activating the coagulation system and by generating thrombin that activates platelets in mouse models. Finally, there is an association between EVTF activity and venous thrombosis in pancreatic cancer patients as well as mortality in cancer patients.

SUMMARY

Cancer cell-derived TF+EVs bind to and activate endothelial cells. In addition, they serve as biomarkers of survival of cancer patients and venous thrombosis in pancreatic 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.

Hyperglycemia and T Cell infiltration are associated with stromal and epithelial prostatic hyperplasia in the nonobese diabetic mouse

BACKGROUND

Prostatic inflammation and various proinflammatory systemic comorbidities, such as diabetes and obesity are associated with human benign prostatic hyperplasia (BPH). There is a paucity of in vivo models reflecting specific aspects of BPH pathogenesis. Our aim was to investigate the nonobese diabetic (NOD) mouse as a potential model for subsequent intervention studies.

MATERIALS AND METHODS

We used the NOD mouse, a model of autoimmune inflammation leading to type 1 diabetes to examine the effects of systemic inflammation and diabetes on the prostate. We assessed changes in prostatic histology, infiltrating leukocytes, and gene expression associated with aging and diabetic status.

RESULTS

Both stromal expansion and epithelial hyperplasia were observed in the prostates. Regardless of diabetic status, the degree of prostatic hyperplasia varied. Local inflammation was associated with a more severe prostatic phenotype in both diabetic and nondiabetic mice. Testicular atrophy was noted in diabetic mice, but prostate glands showed persistent focal cell proliferation. In addition, a prostatic intraepithelial neoplasia (PIN)-like phenotype was seen in several diabetic animals with an associated increase in c-Myc and MMP-2 expression. To examine changes in gene and cytokine expression we performed microarray and cytokine array analysis comparing the prostates of diabetic and nondiabetic animals. Microarray analysis revealed several differentially expressed genes including CCL3, CCL12, and TNFS10. Cytokine array analysis revealed increased expression of cytokines and proteases such as LDLR, IL28 A/B, and MMP-2 in diabetic mice.

CONCLUSION

Overall, NOD mice provide a model to examine the effects of hyperglycemia and chronic inflammation on the prostate, demonstrating relevance to some of the mechanisms present underlying BPH and potentially the initiation of prostate cancer.

Tissue Factor and Cancer: Regulation, Tumor Growth, and Metastasis

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.

Tisotumab vedotin in patients with advanced or metastatic solid tumours (InnovaTV 201): a first-in-human, multicentre, phase 1-2 trial

BACKGROUND

Tisotumab vedotin is a first-in-human antibody-drug conjugate directed against tissue factor, which is expressed across multiple solid tumour types and is associated with poor clinical outcomes. We aimed to establish the safety, tolerability, pharmacokinetic profile, and antitumour activity of tisotumab vedotin in a mixed population of patients with locally advanced or metastatic (or both) solid tumours known to express tissue factor.

METHODS

InnovaTV 201 is a phase 1-2, open-label, dose-escalation and dose-expansion study done at 21 centres in the USA and Europe. Patients (aged ≥18 years) had relapsed, advanced, or metastatic cancer of the ovary, cervix, endometrium, bladder, prostate, oesophagus, squamous cell carcinoma of the head and neck or non-small-cell lung cancer; an Eastern Cooperative Oncology Group performance status of 0-1; and had relapsed after or were not eligible to receive the available standard of care. No specific tissue factor expression level was required for inclusion. In the dose-escalation phase, patients were treated with tisotumab vedotin between 0·3 and 2·2 mg/kg intravenously once every 3 weeks in a traditional 3 + 3 design. In the dose-expansion phase, patients were treated at the recommended phase 2 dose. The primary endpoint was the incidence of adverse events, including serious adverse events, infusion-related, treatment-related and those of grade 3 or worse, and study drug-related adverse events, analysed in all patients who received at least one dose of tisotumab vedotin (full analysis population). This trial is registered with ClinicalTrials.gov, number NCT02001623, and is closed to new participants with follow-up ongoing.

FINDINGS

Between Dec 9, 2013, and May 18, 2015, 27 eligible patients were enrolled to the dose-escalation phase. Dose-limiting toxicities, including grade 3 type 2 diabetes mellitus, mucositis, and neutropenic fever, were seen at the 2·2 mg/kg dose; therefore, 2·0 mg/kg of tisotumab vedotin intravenously once every 3 weeks was established as the recommended phase 2 dose. Between Oct 8, 2015, and April 26, 2018, 147 eligible patients were enrolled to the dose-expansion phase. The most common (in ≥20% of patients) treatment-emergent adverse events of any grade were epistaxis (102 [69%] of 147 patients), fatigue (82 [56%]), nausea (77 [52%]), alopecia (64 [44%]), conjunctivitis (63 [43%]), decreased appetite (53 [36%]), constipation (52 [35%]), diarrhoea (44 [30%]), vomiting (42 [29%]), peripheral neuropathy (33 [22%]), dry eye (32 [22%]), and abdominal pain (30 [20%]). The most common adverse events of grade 3 or worse were fatigue (14 [10%] of 147 patients), anaemia (eight [5%]), abdominal pain (six [4%]), hypokalaemia (six [4%]), conjunctivitis (five [3%]), hyponatraemia (five [3%]), and vomiting (five [3%]). 67 (46%) of 147 patients had a treatment-emergent serious adverse event. 39 (27%) of 147 patients had a treatment-emergent serious adverse event related to the study drug. Infusion-related reactions occurred in 17 (12%) of 147 patients. Across tumour types, the confirmed proportion of patients who achieved an objective response was 15·6% (95% CI 10·2-22·5; 23 of 147 patients). There were nine deaths across all study phases (three in the dose-escalation phase and six in the dose-expansion phase); only one case of pneumonia in the dose-expansion phase was considered possibly related to study treatment.

INTERPRETATIONS

Tisotumab vedotin has a manageable safety profile with encouraging preliminary antitumour activity across multiple tumour types in heavily pretreated patients. Continued evaluation of tisotumab vedotin is warranted in solid tumours.

FUNDING

Genmab A/S.

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.

Challenges in Optimising the Successful Construction of Antibody Drug Conjugates in Cancer Therapy

Although considerable progress has been made in the field of cancer chemotherapy, there remains a significant unmet medical need, with a requirement to move away from traditional cytotoxics and explore novel, smarter chemotherapeutic approaches. One such example of the smart chemotherapy approach is antibody-drug conjugates (ADCs), which consist of an antibody that binds selectively to a cancer antigen linked to a cytotoxic agent. When developing an ADC, it may be necessary to produce a variety of constructs to fully assess the optimal configuration for the molecule. By testing ADCs prepared using a range of cytotoxic agents, linkers, or different antibodies, it is possible to fully assess the optimal approach for this treatment modality before advancing to the clinic. Since the development and approval of first-generation ADCs, significant improvements in development technology have occurred. Here, we consider the advances made within the field of ADCs, focusing on the development of EDO-B278 and EDO-B776, both of which have demonstrated efficacy in preclinical testing. Although some limitations remain in this field of development, the potential reduction in toxicity offered by ADCs justifies the investment in research to find workable solutions that could ultimately provide patients with superior outcomes.

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.

Prognostic significance of the digit ratio after hormone therapy for prostate cancer: a prospective multicenter study

The digit ratio has been used as a retrospective noninvasive biomarker to investigate the putative effects of prenatal exposure to androgens. In recent years, many scholars have paid attention to the association between 2D:4D (the second and fourth digits) and prostatic cancer. This study explored the prognostic significance of digit ratio in prostate cancer patients. We reviewed the progressive status and survival of 382 prostate cancer patients who had received hormone therapy at our institutions. Survival of clinicopathological variables analyzed as categorical variables were determined by the log-rank test. According to Cox’s proportional hazards analysis, R2D:4D, L2D:4D, PSA at 6 month,bone metastasis were significant independent factors for prostate cancer. The risk of any progression of prostate cancer similarly depressed with increasing 2D:4D, for any progression (R2D:4D HR = 0.71, p = 0.003; L2D:4D HR = 0.67, p = 0.001), for cancer-specific death (R2D:4D HR = 0.67, p = 0.025; L2D:4D HR = 0.74, p = 0.036). Digit ratio may not only have predictive value in risk but also prognosis of prostatic cancer. This finding suggests that low 2D:4D can be used as prognostic factors to identify patients with a poor prognosis. These patients may benefit from more aggressive management.

Polymorphisms of the coagulation system and risk of cancer

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.

Thromboelastography identifies hypercoagulablilty and predicts thromboembolic complications in patients with prostate cancer

Cancer patients are at higher risk for thromboembolism compared to the normal population. This may be related to tumour burden and/or enhanced by systemic therapy. While there is ample evidence regarding venous thromboembolism, systematic studies investigating arterial thrombotic events are scarce. Conventional coagulation tests have limited capacity in evaluating the coagulability or the need for anticoagulant prophylaxis. In this pilot study, we investigated whether assessment of global haemostasis using thromboelastography (TEG) and quantification of plasma pro-coagulant microparticles can help determine the risk of adverse thrombotic events in patients with prostate cancer (PCa). Thirty two patients were recruited a priori into three groups: 11 men on 'watchful waiting' following recurrent disease after definitive treatment (Group A); 10 patients with metastatic disease on Androgen deprivation therapy (ADT) (Group B); and 11 with castration resistant cancer (Group C) and followed up over a period of 12months. These patients were compared to a control group composed of 8 men with negative prostate biopsy. Whole blood TEG and plasma tissue factor-carrying microparticles (TF-MPs) in addition to basic coagulation testing, plasma fibrinogen and d-dimer were performed. 22/32 (68.8%) of the patients demonstrated hypercoagulable TEG traces. Hypercoagulability was marked in group B compared to the control. Plasma MPs were significantly elevated in patients compared to the controls with significant increase in group B. All other coagulation tests were normal. Seven of the 22 hypercoagulable patients (31.8%) developed one or more thromboembolic events over 12months follow up period. The data in this pilot study show that PCa patients are hypercoagulable, particularly those with advanced disease on ADT and that this hypercoagulability can be identified by TEG. While this needs to be verified in a larger study, the data indicate TEG may aid in thrombosis risk stratification and determining the subsequent need for anticoagulant prophylaxis in PCa patients.

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.

Circulating microparticle tissue factor, thromboembolism and survival in pancreaticobiliary cancers

BACKGROUND

Tissue factor (TF), the physiologic initiator of coagulation, is over-expressed in pancreatic cancer, and is associated with a pro-coagulant and pro-angiogenic state. We hypothesized that in patients with pancreaticobiliary cancers (PBC), elevated circulating microparticle-associated TF (MP-TF) activity would be associated with thrombosis and worsened survival.

PATIENTS AND METHODS

Clinical data and plasma were obtained for consecutive patients with PBC seen at Roswell Park Cancer Institute from 2005-08. MP-TF activity levels were measured using a TF-dependent FXa generation assay.

RESULTS

The study population comprised 117 patients, including pancreatic (n=80), biliary (n=34) or unknown primary histologically consistent with PBC (n=3). Of these, 52 patients (44.5%) experienced thromboembolism, including pulmonary embolism (n=15), deep venous thrombosis (n=21) and other arterial or venous events (n=32). Mean TF was 2.15 (range 0.17- 31.01) pg/mL. Median survival was 98.5 days for MP-TF activity ≥ 2.5 pg/mL versus 231 days for MP-TF activity<2.5 pg/mL (p<0.0001). In multivariate analysis, elevated MP-TF activity was associated with both VTE (OR 1.4, 95% CI 1.1-1.6) and mortality (HR 2.5, 95% CI 1.4-4.5).

CONCLUSIONS

Elevated circulating MP-TF activity is associated with thrombosis and worsened survival in patients with PBC. MP-TF activity as a prognostic biomarker warrants further prospective evaluation.

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.

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.

Tissue factor-activated coagulation cascade in the tumor microenvironment is critical for tumor progression and an effective target for therapy

Tissue factor (TF), a rate-limiting enzyme cofactor in activating coagulation, is highly expressed in a wide spectrum of human tumor and tumor stromal cells. Using TF-deficient cancer cells and a conditional TF-knockout mouse model, we show that TF expressed by cancer cells, but not by the host stromal cells, plays a critical role in tumor growth. In the tumor microenvironment, serum coagulation factors are readily extravasated and therefore lead to continuous TF-mediated activation of coagulation proteases. To target this highly specific cascade of serine proteases, we used both a TF:VIIa inhibitor and doxorubicin-based prodrugs that are selectively activated by TF:FVIIa, FXa, and thrombin. Treatment with the TF:FVIIa inhibitor led to growth retardation in breast tumor models. In contrast, treatment with the prodrug eliminated primary tumor cells and lung metastases without apparent toxicity. Our findings offer preclinical proof of principle that targeting the coagulation cascade that is activated in the tumor microenvironment can be a highly effective approach for cancer therapy.

Circulating endothelial cells, circulating tumour cells, tissue factor, endothelin-1 and overall survival in prostate cancer patients treated with docetaxel

PURPOSE

We investigated whether serum markers of angiogenesis endothelin-1 (ET-1) and tissue factor (TF), and/or markers of vascular damage such as circulating endothelial cells (CECs), or their relative changes during treatment, were prognostic for overall survival (OS) in castration resistant prostate cancer (CRPC) patients. Additionally, we combined these markers with circulating tumour cells (CTCs) to construct a predictive nomogram for treatment outcome.

PATIENTS AND METHODS

One hundred and sixty two CRPC patients treated with a docetaxel containing regimen had blood drawn before and at 2-5 weeks and 6-8 weeks after treatment start. Prospectively determined CTC and CEC levels, and retrospectively measured serum concentrations of ET-1 (pg/mL) and TF (pg/mL) were evaluated to determine their prognostic value for OS.

RESULTS

Baseline CEC, TF and ET-1 were not prognostic for OS. A > or = 3.8-fold increase in CEC 2-5 weeks after treatment initiation was associated with decreased OS (median 10.9 versus 16.8 months; P=0.015), as was any decrease in TF levels compared to baseline levels (median 11.9 versus 21.5 months; P=0.0005). As previously published, baseline and CTC counts > or = 5 at 2-5 weeks were also predictive of decreased OS. Combining CTC with changes in TF and CEC 2-5 weeks after treatment initiation yielded four groups differing in OS (median OS 24.2 versus 16.0 versus 11.4 versus 6.1 months; P<0.0001).

CONCLUSION

CEC, CTC and TF levels alone and combined can predict early on OS in CRPC patients treated with docetaxel-based therapy. A prospective study to confirm the use of these markers for patient management is needed.

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.

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.

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.

Relation between hemostatic parameters and prognostic/predictive factors in breast cancer

BACKGROUND

In our study, we searched for a relation between various prognostic and predictive factors and hemostatic parameters.

METHODS

One hundred women with newly diagnosed breast cancer after surgery were included. Patients did not receive systemic therapy or radiotherapy. The control group included 100 healthy, age-matched women. In the patient group, age, menopausal status, tumor size, grade, axillary lymph node status, steroid receptor status, p53, and HER2/neu were evaluated. Plasma levels of factor VIII, factor IX, D-dimer, fibrinogen, protein C, protein S, vWF, and antithrombin III were measured in both groups.

RESULTS

Plasma levels of factor VIII, factor IX, vWF, and CRP in patients with breast cancer were higher than those in controls. Protein S levels in patients were lower than in controls. There was no significant difference in other hemostatic parameters between the groups. In patients with axillary lymph node metastasis, factor VIII levels were significantly higher than in node-negative patients. There was a strong correlation between axillary lymph node status, number of metastatic nodes, and factor VIII levels. There was no correlation between factor VIII levels and CRP. Factor VIII levels were higher in the group having high HER2/neu (3+) than in the group with negativity for HER2/neu.

CONCLUSION

There was a strong correlation between axillary lymph node involvement, number of metastatic nodules, overexpression of HER2/neu, hemostatic parameters, and factor VIII levels. Our study showed that factor VIII level measurement can provide additional data for evaluation of breast cancer patients' prognosis.

Use of mouse models to study the role of tissue factor in tumor biology

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.

Hemostatic complications of angiogenesis inhibitors in cancer patients

Tumor vasculature and tumor-associated neo-angiogenesis have recently become major targets for rational drug design of antineoplastic agents. Five such agents with angiogenesis inhibiting activity (thalidomide, lenalidomide, bevacizumab, sunitinib, sorafenib) have already obtained US Food and Drug Administration approval for clinical use and many others have entered clinical trials. Vascular complications, including venous or arterial thromboembolism and hemorrhage, have emerged as relevant toxicities in several clinical trials with angiogenesis inhibitors. Given the well-known interplay between the blood clotting system, angiogenesis, and tumor growth, a better understanding of the impact of these new drugs on overall hemostatic balance is required. In this brief overview, we discuss the incidence of hemostatic complications, the likely pathogenetic mechanisms involved, and the critical need to establish in randomized clinical trials the usefulness of thrombosis prophylaxis to prevent these complications. Careful documentation of hemostatic complications during treatment with each of the new antiangiogenic drugs is warranted. Further studies are urgently required to better define the causal association of these new agents with hemostatic complications and to establish the best prophylactic strategy.

Tissue factor/FVIIa activates Bcl-2 and prevents doxorubicin-induced apoptosis in neuroblastoma cells

Background

Tissue factor (TF) is a transmembrane protein that acts as a receptor for activated coagulation factor VII (FVIIa), initiating the coagulation cascade. Recent studies demonstrate that expression of tumor-derived TF also mediates intracellular signaling relevant to tumor growth and apoptosis. Our present study investigates the possible mechanism by which the interaction between TF and FVIIa regulates chemotherapy resistance in neuroblastoma cell lines.

Methods

Gene and siRNA transfection was used to enforce TF expression in a TF-negative neuroblastoma cell line and to silence endogenous TF expression in a TF-overexpressing neuroblastoma line, respectively. The expression of TF, Bcl-2, STAT5, and Akt as well as the phosphorylation of STAT5 and Akt in gene transfected cells or cells treated with JAK inhibitor and LY294002 were determined by Western blot assay. Tumor cell growth was determined by a clonogenic assay. Cytotoxic and apoptotic effect of doxorubicin on neuroblastoma cell lines was analyzed by WST assay and annexin-V staining (by flow cytometry) respectively.

Results

Enforced expression of TF in a TF-negative neuroblastoma cell line in the presence of FVIIa induced upregulation of Bcl-2, leading to resistance to doxorubicin. Conversely, inhibition of endogenous TF expression in a TF-overexpressing neuroblastoma cell line using siRNA resulted in down-regulation of Bcl-2 and sensitization to doxorubicin-induced apoptosis. Additionally, neuroblastoma cells expressing high levels of either endogenous or transfected TF treated with FVIIa readily phosphorylated STAT5 and Akt. Using selective pharmacologic inhibitors, we demonstrated that JAK inhibitor I, but not the PI3K inhibitor LY294002, blocked the TF/FVIIa-induced upregulation of Bcl-2.

Conclusion

This study shows that in neuroblastoma cell lines overexpressed TF ligated with FVIIa produced upregulation of Bcl-2 expression through the JAK/STAT5 signaling pathway, resulting in resistance to apoptosis. We surmise that this TF-FVIIa pathway may contribute, at least in part, to chemotherapy resistance in neuroblastoma.

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.

Fibrinogen synthesized by cancer cells augments the proliferative effect of fibroblast growth factor-2 (FGF-2)

BACKGROUND

Fibroblast growth factor (FGF)-2 is a critical growth factor in normal and malignant cell proliferation and tumor-associated angiogenesis. Fibrinogen and fibrin bind to FGF-2 and modulate FGF-2 functions. Furthermore, we have shown that extrahepatic epithelial cells are capable of endogenous production of fibrinogen.

OBJECTIVE

Herein we examined the role of fibrinogen and FGF-2 interactions on prostate and lung adenocarcinoma cell growth in vitro.

METHODS

Cell proliferation was measured by (3)H-thymidine uptake and the specificity of FGF-2-fibrinogen interactions was measured using wild-type and mutant FGF-2s, fibrinogen gamma-chain (FGG) RNAi and co-immunoprecipitation. Metabolic labeling, immunopurification and fluorography demonstrated de novo fibrinogen production.

RESULTS

FGF-2 stimulated DU-145 cell proliferation, whereas neither FGF-2 nor fibrinogen affected the growth of PC-3 or A549 cells. Fibrinogen augmented the proliferative effect of FGF-2 on DU-145 cells. The role of fibrinogen in FGF-2-enhanced DNA synthesis was confirmed using an FGF-2 mutant that exhibits no binding affinity for fibrinogen. FGG transcripts were present in PC-3, A549 and DU-145 cells, but only PC-3 and A549 cells produced detectable levels of intact protein. RNAi-mediated knockdown of FGG expression resulted in decreased production of fibrinogen protein and inhibited (3)H-thymidine uptake in A549 and PC-3 cells by 60%, which was restored by exogenously added fibrinogen. FGF-2 and fibrinogen secreted by the cells were present in the medium as a soluble complex, as determined by coimmunoprecipitation studies.

CONCLUSIONS

These data indicate that endogenously synthesized fibrinogen promotes the growth of lung and prostate cancer cells through interaction with FGF-2.

Tumor cell-associated tissue factor and circulating hemostatic factors cooperate to increase metastatic potential through natural killer cell-dependent and-independent mechanisms

Tumor cell-associated tissue factor (TF) is a powerful determinant of metastatic potential. TF may increase metastasis by supporting thrombin-mediated proteolysis, through intracellular signaling events mediated by the TF cytoplasmic domain, through TF/fVIIa/fXa-mediated activation of protease-activated receptors, or through a combination of these processes. To better define the relationship between tumor cell-associated TF and circulating hemostatic factors in malignancy, we generated a set of C57Bl/6-derived tumor lines genetically lacking TF, expressing wild-type murine TF, or expressing a mutant TF lacking the cytoplasmic domain. Comparison of the metastatic potential of these cells in immunocompetent mice with genetic deficits in prothrombin, platelet function, or fibrinogen revealed that TF supports metastasis through mechanisms independent of the cytoplasmic domain, but dependent on each of these distal hemostatic factors. TF was neither required for primary tumor growth nor necessary for initial localization of embolized tumor cells within the lungs. Rather, tumor cell fate studies indicated TF supports metastasis by increasing the survival of micrometastases. One mechanism linking TF to metastasis is through a fibrin(ogen)-dependent and platelet-dependent restriction in natural killer cell-mediated clearance of micrometastases. However, TF also supported the early success of micrometastases through an additional mechanism independent of natural killer cells, but coupled to circulating prothrombin.

Prothrombotic effect of prostasomes of metastatic cell and seminal origin

BACKGROUND

Prostasomes are secretory granules produced by the glandular epithelial cells of the prostate. Seminal prostasomes contain high amounts of Tissue Factor (TF) but no studies of TF on malignant cell prostasomes have been made. Here we compare the expression, phosphorylation, and function of TF on prostasomes of different origin.

METHODS

TF was detected on prostasomes isolated from seminal fluid and human prostate cancer cell lines (PC-3, DU145, and LNCaP) using FACS and enzyme immunoassay (EIA). Incubation of prostasomes with radioactive ATP under conditions favoring protein kinase A activity led to phosphorylation of TF as detected by immunoprecipitation and SDS-PAGE. The prothrombotic effect of prostasomes was investigated in whole blood and recalcified plasma. Blocking experiments were performed using anti-TF antibodies and corn trypsin inhibitor.

RESULTS

TF was expressed on all tested prostasome preparations with lowest values found for seminal ones. Prostasomal TF was the main endogenous substrate for prostasomal protein kinase A. All tested prostasome preparations greatly enhanced the rate of clot formation in a dose-dependent fashion, that is, the clotting capability of prostasomes seemed to be related to the extent of their expression of TF. In addition, the density of the clot varied between different prostasome preparations. When incubated in whole blood, prostasomes were found to associate to WBC thereby inducing them to express and release TF.

CONCLUSIONS

These data show that TF is overexpressed and also subjected to phosphorylation by malignant cell prostasomes. This suggests major roles for prostasomes in thrombotic events that occur in some advanced cases of prostate cancer.

Ex vivo and In vivo Delivery of Anti-Tissue Factor Short Interfering RNA Inhibits Mouse Pulmonary Metastasis of B16 Melanoma Cells

PURPOSE

The coagulation trigger tissue factor has been implicated in tumor growth, angiogenesis, and metastasis. In this study, we explore the effects of ex vivo and in vivo delivery of short interfering RNA (siRNA) targeting tissue factor on B16 melanoma colonization of the lung in a murine model for metastasis. The purposes of this work are to establish a noncytotoxic in vivo model for investigation of tissue factor function and provide preclinical assessment of the therapeutic potential of tissue factor siRNA for prevention of metastasis.

EXPERIMENTAL DESIGN AND RESULTS

C57BL/6 mice were evaluated for pulmonary metastases following tail vein injection of B16 cells transfected with either active or inactive siRNA. Mice receiving cells transfected with active siRNA had significantly lower numbers of pulmonary tumors compared with mice injected with control cells (transfected with inactive siRNA). The average time point at which the mice started to exhibit tumor-associated stress was also increased significantly from 22 days for the control group to 27 days for the experimental group (P = 0.01). In a therapeutically more relevant model, where the siRNA was delivered i.p. and the cells (untransfected) by tail vein injection, an inhibitory effect on metastasis was observed when the siRNA treatment was initiated either before or at the time of cell injection.

CONCLUSIONS

The results suggest that tissue factor has a crucial function in promoting lung tumor metastasis of blood-borne tumor cells in the early stages of the tumor take process and further suggest that treatment with tissue factor siRNA may become a viable clinical strategy for prevention of tumor metastasis.

Impact of IGF-I and CYP19 gene polymorphisms on the survival of patients with metastatic prostate cancer

PURPOSE

The prognosis of metastatic prostate cancer significantly differs among individuals. While various clinical and biochemical prognostic factors for survival have been suggested, the progression and response to treatment of those patients may also be defined by host genetic factors. In this study, we evaluated genetic polymorphisms as prognostic predictors of metastatic prostate cancer.

PATIENTS AND METHODS

One hundred eleven prostate cancer patients with bone metastasis at the diagnosis were enrolled in this study. Thirteen genetic polymorphisms were genotyped using polymerase chain reaction-restriction fragment length polymorphism or an automated sequencer with a genotyping software.

RESULTS

Among the polymorphisms, the long allele (over 18 [CA] repeats) of insulin-like growth factor-I (IGF-I) and the long allele (over seven [TTTA] repeats) of cytochrome P450 (CYP) 19 were significantly associated with a worse cancer-specific survival (P = .016 and .025 by logrank test, respectively). The presence of the long allele of either the IGF-I or CYP19 polymorphisms was an independent risk factor for death (P = .019 or .026, respectively). Furthermore, the presence of the long allele of both the IGF-I and CYP19 polymorphisms was a stronger predictor for survival (P = .001).

CONCLUSION

The prognosis of metastatic prostate cancer patients is suggested to be influenced by intrinsic genetic factors. The IGF-I (CA) repeat and CYP19 (TTTA) repeat polymorphisms may be novel predictors in prostate cancer patients with bone metastasis at the diagnosis.

Preoperative serum tissue factor levels are an independent prognostic factor in patients with ovarian carcinoma

PURPOSE

Tissue factor (TF) is a procoagulant that plays an important part in tumor angiogenesis. We sought to determine the role of preoperative serum TF levels in predicting clinical outcome in patients with ovarian cancer.

MATERIALS AND METHODS

TF expression was determined by reverse transcriptase polymerase chain reaction in ovarian cell lines. Using enzyme-linked immunosorbent assay, we assessed preoperative serum TF levels in 98 women with invasive epithelial ovarian carcinoma, 30 with low malignant potential (LMP) tumors, 16 with benign tumors, and a separate validation group of 39 women with adnexal masses. Clinical information was gathered from chart review.

RESULTS

TF was expressed in four of the five ovarian cancer cell lines, but absent in the nontransformed cells. Ovarian cancer patients had a median preoperative serum TF level of 85.2 pg/mL, which was significantly higher than in those with LMP tumors (12.8 pg/mL; P < .01) and benign adnexal disease (30.7 pg/mL; P < .01). TF >or= 190 pg/mL was significantly associated with decreased patient survival (P < .01). After adjusting for other clinical variables in a multivariate Cox regression model, TF >or= 190 pg/mL was an independent prognostic factor (P < .01). Analysis of serum TF levels from the validation set confirmed that high TF (>or=190 pg/mL) was associated with a 3.4-fold increase in risk of death from disease (P = .02) and shorter survival (P = .01).

CONCLUSION

Preoperative serum TF levels are significantly elevated in patients with ovarian carcinoma. Elevated preoperative TF level is an independent prognostic factor for death from disease.

Radiotherapy of human xenograft NSCLC tumors in nude mice with a 90Y-labeled anti-tissue factor antibody

Tissue factor (TF) is a type I transmembrane protein and the initiator of the extrinsic blood coagulation pathway. TF plays a critical role in tumor development and its overexpression is observed in many tumors. To understand the prevalence and relative level of TF expression in non-small-cell lung cancer (NSCLC), we analyzed 50 NSCLC tumors by immunohistochemical staining and found that 88% of human NSCLC tumors overexpressed TF. We then generated a high affinity anti-TF antibody, TF278, which specifically binds TF on the surface of cells and is internalized upon binding. An 111In-labeled TF278 demonstrated favorable tumor accumulation in an SW-900 xenograft tumor model with a maximum mean percent of injected dose per gram of tissue (%ID/g) of 73.1% at 96 hours postinjection. In addition, we labeled the antibody with 90Y and tested its ability to inhibit the growth of tumors in an SW-900 xenograft tumor model in immunocompromised mice. The 90Y-TF278 slowed the growth of SW-900 tumors at a 50 microCi dose and completely regressed SW-900 tumors at a 150 microCi dose with little toxicity.

Tissue factor and tumor: clinical and laboratory aspects

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.

Characterization of Human Tissue Factor (TF)–Specific Monoclonal Antibodies Prepared Using a Rapid Immunization Protocol

Tissue factor (TF) plays an important, physiological role in hemostasis. Recent studies have demonstrated the over-expression of TF in a number of solid tumor types and its pathological roles in angiogenesis and tumor metastasis. In this study, we report the development and characterization of a panel of murine MAbs that are specific for human TF, but do not inhibit TF-mediated blood coagulation. By using a modified repetitive immunizations at multiple sites (RIMMS) protocol in conjunction with an efficient hybridoma cloning procedure, anti-TF MAbs were generated within a relatively short time frame of 5-6 weeks. Following primary screening by ELISA, the binding of the MAbs to the native form of human TF was demonstrated in flow cytometry using a stable cell line expressing human TF. Several of these TF-specific MAbs did not inhibit blood coagulation in a blood coagulation assay and bound with high affinity (0.5-2 nM) to human TF in BIAcore analyses. Importantly, this study represents an independent evaluation of the RIMMS strategy for MAb generation and demonstrates that class-switched, high-affinity MAbs can be generated rapidly and reliably using RIMMS.

Activation of the coagulation system in cancerogenesis and metastasation

The activation of the coagulation system in cancer patients is a well-known phenomenon responsible for recurrent clinical problems. A number of fascinating molecular mechanisms have been recognized showing that the tumor not only activates the coagulation system, but vice versa, activated coagulation proteins are able to induce molecular effects in tumor cells. The molecular basis is the expression of defined membrane receptors by tumor cells that are activated, for example, by thrombin. As the liberation of thrombin from prothrombin is one of the key events in coagulation, it's impact upon biological processes, such as cancerogenesis and metastasation, seems to be a regular pathophysiological consequence. These perceptions are not only interesting for the comprehension of cancerogenesis, metastasation, and clinical phenomena, but they also have a high impact upon modern strategies of tumor therapy. Especially, the development of clinically useful coagulation inhibitors, such as modern low molecular weight heparins or melagatran, created the possibility of therapies that combine cell biological approaches with apoptosis-inducing principals such as chemotherapy. Several clinical studies that demonstrate the implication of these strategies have already been published recently. In this article the cell biological basics for these approaches are reviewed.