Genetic pathways linking hemostasis and cancer

Antibody Profiling and In Silico Functional Analysis of Differentially Reactive Antibody Signatures of Glioblastomas and Meningiomas

Studies on tumor-associated antigens in brain tumors are sparse. There is scope for enhancing our understanding of molecular pathology, in order to improve on existing forms, and discover new forms, of treatment, which could be particularly relevant to immuno-oncological strategies. To elucidate immunological differences, and to provide another level of biological information, we performed antibody profiling, based on a high-density protein array (containing 8173 human transcripts), using IgG isolated from the sera of n = 12 preoperative and n = 16 postoperative glioblastomas, n = 26 preoperative and n = 29 postoperative meningiomas, and n = 27 healthy, cancer-free controls. Differentially reactive antigens were compared to gene expression data from an alternate public GBM data set from OncoDB, and were analyzed using the Reactome pathway browser. Protein array analysis identified approximately 350-800 differentially reactive antigens, and revealed different antigen profiles in the glioblastomas and meningiomas, with approximately 20-30%-similar and 10-15%-similar antigens in preoperative and postoperative sera, respectively. Seroreactivity did not correlate with OncoDB-derived gene expression. Antigens in the preoperative glioblastoma sera were enriched for signaling pathways, such as signaling by Rho-GTPases, COPI-mediated anterograde transport and vesicle-mediated transport, while the infectious disease, SRP-dependent membrane targeting cotranslational proteins were enriched in the meningiomas. The pre-vs. postoperative seroreactivity in the glioblastomas was enriched for antigens, e.g., platelet degranulation and metabolism of lipid pathways; in the meningiomas, the antigens were enriched in infectious diseases, metabolism of amino acids and derivatives, and cell cycle. Antibody profiling in both tumor entities elucidated several hundred antigens and characteristic signaling pathways that may provide new insights into molecular pathology and may be of interest for the development of new treatment strategies.

The role of extracellular vesicles in traumatic brain injury-induced acute lung injury

Acute lung injury (ALI), a common complication after traumatic brain injury (TBI), can evolve into acute respiratory distress syndrome (ARDS) and has a mortality rate of 30%-40%. Secondary ALI after TBI exhibits the following typical pathological features: infiltration of neutrophils into the alveolar and interstitial space, alveolar septal thickening, alveolar edema, and hemorrhage. Extracellular vesicles (EVs) were recently identified as key mediators in TBI-induced ALI. Due to their small size and lipid bilayer, they can pass through the disrupted blood-brain barrier (BBB) into the peripheral circulation and deliver their contents, such as genetic material and proteins, to target cells through processes such as fusion, receptor-mediated interactions, and uptake. Acting as messengers, EVs contribute to mediating brain-lung cross talk after TBI. In this review, we aim to summarize the mechanism of EVs in TBI-induced ALI, which may provide new ideas for clinical treatment.

Hemostatic Biomarkers and Cancer Prognosis: Where Do We Stand?

Cancer patients are characterized by hypercoagulable state and an increased rate of thrombotic events, the most common being venous thromboembolism. Several hemostatic pathways that are significantly implicated in mechanisms of thromboembolic disease are also involved in growth, invasion, and metastatic spread of malignant cells as well in tumor-induced neo-angiogenesis. This close connection between cancer and the hemostatic system has prompted numerous studies on the role of alterations in the level plasma biomarkers of the different compartments of hemostasis in predicting cancer prognosis. In this review, we collect the results of several exemplificative studies that have evaluated clotting activation biomarkers in relation to different cancer outcomes with a final emphasis on current research and forthcoming directions in this field.

Seizures, Edema, Thrombosis, and Hemorrhages: An Update Review on the Medical Management of Gliomas

Patients affected with gliomas develop a complex set of clinical manifestations that deeply impact on quality of life and overall survival. Brain tumor-related epilepsy is frequently the first manifestation of gliomas or may occur during the course of disease; the underlying mechanisms have not been fully explained and depend on both patient and tumor factors. Novel treatment options derive from the growing use of third-generation antiepileptic drugs. Vasogenic edema and elevated intracranial pressure cause a considerable burden of symptoms, especially in high-grade glioma, requiring an adequate use of corticosteroids. Patients with gliomas present with an elevated risk of tumor-associated venous thromboembolism whose prophylaxis and treatment are challenging, considering also the availability of new oral anticoagulant drugs. Moreover, intracerebral hemorrhages can complicate the course of the illness both due to tumor-specific characteristics, patient comorbidities, and side effects of antithrombotic and antitumoral therapies. This paper aims to review recent advances in these clinical issues, discussing the medical management of gliomas through an updated literature review.

Activation of PAR2 by tissue factor induces the release of the PTEN from MAGI proteins and regulates PTEN and Akt activities

Tissue factor (TF) signalling has been associated with alterations in Akt activity influencing cellular survival and proliferation. TF is also shown to induce signalling through activation of the protease activated receptor (PAR)2. Seven cell lines were exposed to recombinant-TF (rec-TF), or activated using a PAR2-agonist peptide and the phosphorylation state of PTEN, and the activities of PTEN and Akt measured. Furthermore, by measuring the association of PTEN with MAGI proteins a mechanism for the induction of signalling by TF was proposed. Short term treatment of cells resulted in de-phosphorylation of PTEN, increased lipid-phosphatase activity and reduced Akt kinase activity in most of the cell lines examined. In contrast, continuous exposure to rec-TF up to 14 days, resulted in lower PTEN antigen levels, enhanced Akt activity and increased rate of cell proliferation. To explore the mechanism of activation of PTEN by TF, the association of "membrane-associated guanylate kinase-with inverted configuration" (MAGI)1–3 proteins with PTEN was assessed using the proximity ligation assay and by co-immunoprecipitation. The interaction of PTEN with all three MAGI proteins was transiently reduced following PAR2 activation and explains the changes in PTEN activity. Our data is first to show that PAR2 activation directly, or through exposure of cells to TF releases PTEN from MAGI proteins and is concurrent with increases in PTEN phosphatase activity. However, prolonged exposure to TF results in the reduction in PTEN antigen with concurrent increase in Akt activity which may explain the aberrant cell survival, proliferation and invasion associated with TF during chronic diseases.

Platelets and Metastasis: New Implications of an Old Interplay

During the process of hematogenous metastasis, tumor cells interact with platelets and their precursors megakaryocytes, providing a selection driver for the metastatic phenotype. Cancer cells have evolved a plethora of mechanisms to engage platelet activation and aggregation. Platelet coating of tumor cells in the blood stream promotes the successful completion of multiple steps of the metastatic cascade. Along the same lines, clinical evidence suggests that anti-coagulant therapy might be associated with reduced risk of metastatic disease and better prognosis in cancer patients. Here, we review experimental and clinical literature concerning the contribution of platelets and megakaryocytes to cancer metastasis and provide insights into the clinical relevance of anti-coagulant therapy in cancer treatment.

Evaluation of the Epigenetic Demethylation of NRF2, a Master Transcription Factor for Antioxidant Enzymes, in Colorectal Cancer

Background

Epigenetic changes in CpG islands of the promoter regions of homeostasis-related genes, including nuclear factor erythroid 2-related factor 2 (NRF2), have been shown to hold a significant role in the development of colorectal cancer. Therefore, we aimed to examine the DNA demethylation pattern of the NRF2 promoter region in cancerous lesions from patients with colorectal cancer and the association of methylation status with clinicopathological features in the Iranian population.

Methods

In this cross-sectional study, 114 colorectal tissue samples were collected. These samples included: 34 tumour tissue samples, 60 precancerous polyps, and 20 normal tissue samples. The promoter methylation status of the NRF2 gene was examined using methylation-specific PCR. Additionally, the relationship between the methylation status and the clinicopathological features was investigated.

Results

The frequency of NRF2 demethylation in the tumour samples was significantly higher compared to the polyp tissues (p= 0.003) and normal tissue (p= 0.009), indicating that cancerous colorectal tissues exhibit increased demethylation of the NRF2 promoter. After examining the demethylation status of tissue samples, the clinicopathological features were compared to the demethylation results. No significant association was found between NRF2 promoter demethylation and the clinicopathological features of patient samples.

Conclusion

Our findings suggest that the epigenetic modifications leading to NRF2 demethylation found in colorectal tumour samples may contribute to cancer progression from precancerous polyps to cancerous lesions.

Assessment of genetic and non-genetic risk factors for venous thromboembolism in glioblastoma - The predictive significance of B blood group

INTRODUCTION

Venous thromboembolism (VTE) is a common problem among patients with glioblastoma multiforme (GBM) and with some other cancers. Here, we evaluated genetic and non-genetic potential risk factors for VTE among GBM patients.

MATERIALS AND METHODS

A cohort of 139 patients treated with concomitant radiotherapy and temozolomide were included in the study. Next generation sequencing and genotyping approaches were applied to assess genetic risk factors in the haemostatic system. Clinical data including surgery, reoperation as well as blood group and patient information such as age and gender were available from patient records. Logistic regression analysis was performed to asses VTE risk.

RESULTS

In the study 47 patients (34%) were diagnosed for VTE during the course of their disease. When genetic and non-genetic potential risk factors were evaluated, only B blood group was found to be significantly associated with VTE incidence (odds ratio [OR] = 6.91; confidence interval [CI] = 2.19-24.14; P = 0.001). In contrast, A and O blood groups did not correlate with VTE risk. Frontal lobe tumor location also seemed to slightly increase VTE risk compared to other brain sites (OR = 3.14; CI = 1.1-10.7) although the significance level was at borderline (P = 0.05). Current study identified B blood group as the component in non-O blood groups that is responsible for increased VTE risk.

CONCLUSION

In conclusion, these results suggest for the first time that B blood group is predictive for VTE incidence among patients with glioblastoma, information that may be potentially valuable when selecting GBM patients who are at risk for VTE for anticoagulant prophylaxis.

Hemostatic biomarkers in cancer progression

Malignant disease is characterized by a hemostatic imbalance, usually shifted towards a procoagulant direction, and a high incidence of thrombotic complications. The mechanisms of hemostasis that are critically involved in thrombosis are also implicated in tumor progression, angiogenesis, and metastatic spread. As there is a close relationship between cancer and the clotting system, circulating biomarkers of activation of various hemostasis compartments (i.e. coagulation, fibrinolysis, platelets, endothelium, and other blood cells) have been extensively studied to predict cancer outcomes along with predicting the thrombotic risk. In this review, we will summarize the results of published studies and will focus on ongoing research and future directions of clotting activation bioproducts as biomarkers of cancer disease and progression.

Subtype-specific clinical and prognostic relevance of tumor-expressed F5 and regulatory F5 variants in breast cancer: the CoCaV study

Essentials The role of coagulation factor V (encoded by F5) in cancer pathogenesis is unknown. The clinical significance of tumor-expressed F5 was evaluated in breast cancer patient cohorts. F5 was expressed in human breast tumors, and the expression was higher than in normal tissue. High F5 expression was associated with aggressive tumors, but also with survival in breast cancer.

SUMMARY

Background Tumor expression of certain coagulation factors has been linked to cancer progression. Single nucleotide polymorphisms (SNPs) in F5 (encoding the FV protein) have been found to be associated with breast cancer; however, the role of coagulation factor V (FV) in cancer pathogenesis remains undiscovered. Objectives We aimed to investigate the clinical significance of FV and the regulatory role of F5 gene variants in breast cancer. Patients/Methods A Scandinavian 503-sample breast cancer cohort and three public breast cancer datasets (GOBO, TCGA and KM plotter) were used to determine associations between F5 gene expression (tumor-specific), circulating FV, F5 SNPs, clinical characteristics and breast cancer survival. Immunohistochemistry (IHC) was used to detect FV antigen in tumors. Results F5 expression was 2-fold higher in breast tumors compared with normal tissue, and the presence of FV antigen in breast tumors was confirmed by IHC staining. F5 expression was increased in patients with hormone receptor negative tumors, triple negative tumors, HER2-enriched and basal-like tumors. In patients with basal tumors, high expression of F5 was associated with improved overall survival (hazard ratio, HR = 0.52, 95% confidence interval, 0.31-0.86). SNPs in F5 were associated with tumor size and luminal A tumors. The rs6427202-rs9332542 C-G haplotype, previously associated with breast cancer, displayed a cis-regulatory effect on F5 expression in tumors and plasma FV antigen levels. In silico mining supported this regulatory function. Conclusions FV was a possible marker of aggressive breast cancer, yet also a predictor of favorable outcome. Evaluation of FV expression may be clinically useful for prognosis and treatment decisions in aggressive breast cancer.

Differentially expressed microRNAs in lung adenocarcinoma invert effects of copy number aberrations of prognostic genes

In many cancers, significantly down- or upregulated genes are found within chromosomal regions with DNA copy number alteration opposite to the expression changes. Generally, this paradox has been overlooked as noise, but can potentially be a consequence of interference of epigenetic regulatory mechanisms, including microRNA-mediated control of mRNA levels.

To explore potential associations between microRNAs and paradoxes in non-small-cell lung cancer (NSCLC) we curated and analyzed lung adenocarcinoma (LUAD) data, comprising gene expressions, copy number aberrations (CNAs) and microRNA expressions. We integrated data from 1,062 tumor samples and 241 normal lung samples, including newly-generated array comparative genomic hybridization (aCGH) data from 63 LUAD samples.

We identified 85 “paradoxical” genes whose differential expression consistently contrasted with aberrations of their copy numbers. Paradoxical status of 70 out of 85 genes was validated on sample-wise basis using The Cancer Genome Atlas (TCGA) LUAD data. Of these, 41 genes are prognostic and form a clinically relevant signature, which we validated on three independent datasets. By meta-analysis of results from 9 LUAD microRNA expression studies we identified 24 consistently-deregulated microRNAs. Using TCGA-LUAD data we showed that deregulation of 19 of these microRNAs explains differential expression of the paradoxical genes.

Our results show that deregulation of paradoxical genes is crucial in LUAD and their expression pattern is maintained epigenetically, defying gene copy number status.

Vascular complications in glioma patients

Vascular complications in patients with glioma most commonly include venous and arterial thromboembolism; however, treatment-induced vasculopathies are also problematic, especially in long-term survivors. The interactions between treatment such as radiation and chemotherapy, the coagulation cascade, endothelium, and regulators of angiogenesis are complex, drive glioma growth and invasion, and create common management problems in the clinic. We review the incidence of thrombotic complications in glioma, the biology of the coagulome as related to glioma progression, prevention and treatment of thrombosis, the role of anticoagulants as anticancer therapy, and vascular complications such as ischemic stroke and intracranial bleeding. The coagulation cascade is intimately involved in cancer-related thrombosis, glioma progression, and vascular complications of glioma therapy. Tissue factor is the principal initiator of coagulation and is upregulated in a glioma subtype-specific fashion. Short-term (perioperative) antithrombotic prophylaxis is effective, but long-term anticoagulation, although attractive, is not routinely indicated. Most patients with symptomatic venous thromboembolism can be safely anticoagulated, including those on anti-vascular endothelial growth factor therapeutics such as bevacizumab. Initial therapy should include low-molecular-weight heparin, and protracted anticoagulant treatment, perhaps indefinitely, is indicated. Many complex interactions resulting in vessel wall injury can lead to ischemic stroke, intracranial and intratumoral hemorrhage, and long-term sequelae such as cognitive impairment.

Data mining of micrornas in breast carcinogenesis which may be a potential target for cancer prevention

The microRNAs (miRNAs) negatively regulate the stability and translation of target messenger RNAs by selectively binding. It has been implicated in diverse processes such as cellular differentiation, cell-cycle control, apoptosis, and carcinogenesis. Examination of tumor-specific miRNA expression profiles has revealed wide spread dysregulation of these molecules in diverse cancers. The available genomic bulk evidences were extracted from The Cancer Genome Atlas by using IluminaGA_miRNASeq platform in human breast cancer samples. After mining collected data, group of each miRNA ID was analyzed through five D/Bs (mirWalk, miranda, mirDB, RNA22, and TargetScan) on predicted and validated miRNA targets. Oncogenes known to have a high correlation with breast cancer (C-myc, HER2, cyclin D-1, N-RAS, FGF-4, FGF-3, BRCA1, and BRCA2) are subject in this study to select their relevant miRNAs. Function of miRNA regulation will be essential to achieve a complete understanding of carcinogenesis and these miRNAs would be potential target for breast cancer prevention.

Integrative Analysis with Monte Carlo Cross-Validation Reveals miRNAs Regulating Pathways Cross-Talk in Aggressive Breast Cancer

In this work an integrated approach was used to identify functional miRNAs regulating gene pathway cross-talk in breast cancer (BC). We first integrated gene expression profiles and biological pathway information to explore the underlying associations between genes differently expressed among normal and BC samples and pathways enriched from these genes. For each pair of pathways, a score was derived from the distribution of gene expression levels by quantifying their pathway cross-talk. Random forest classification allowed the identification of pairs of pathways with high cross-talk. We assessed miRNAs regulating the identified gene pathways by a mutual information analysis. A Fisher test was applied to demonstrate their significance in the regulated pathways. Our results suggest interesting networks of pathways that could be key regulatory of target genes in BC, including stem cell pluripotency, coagulation, and hypoxia pathways and miRNAs that control these networks could be potential biomarkers for diagnostic, prognostic, and therapeutic development in BC. This work shows that standard methods of predicting normal and tumor classes such as differentially expressed miRNAs or transcription factors could lose intrinsic features; instead our approach revealed the responsible molecules of the disease.

Hemostatic disorders of the menopausal period: the role of microRNA

Adverse changes in hemostasis of menopausal women, observed e.g. in atherosclerotic or neoplastic cases, are of multicausal origin. It is believed that in the development and regulation of these processes, an important role is played by microRNA particles, which presence is ascertained in endothelial cells, atherosclerotic plaques and systemic circulation. Discovered for the first time over 20 years ago, up to now over two and a half thousand types of microRNA have been identified in the human body. MicroRNAs are single stranded RNA molecules of 20-24 nucleotides, encoded by the cell's genome and then transcribed by polymerase II. They regulate the expression of a large gene pool, approximately 30% of all genes, in the human body. MicroRNA molecules, like other bioactive molecules – RNA, protein – both play important roles in tumor invasion, metastasis, inflammation, coagulation, and regeneration. What is important, they can be detected not only in tissues (e.g. tumor tissues), but also in circulation (blood serum), where they are released. Accurate understanding of the role played by certain types of microRNA (e.g. miR-126, miR-17-92, miR-33, miR-613, miR-27a/b, miR-143, miR-335, miR-370, miR-122, miR-19b, miR-520, or miR-220) in hemostatic processes may allow in the future for their use not only as specific biomarkers of cardiovascular diseases but also as the target for innovative gene therapies.

Platelets, coagulation and fibrinolysis in breast cancer progression

The progression of breast cancer from early-stage to metastatic disease results from a series of events during which malignant cells invade and travel within the bloodstream to distant sites, leading to a clonogenic accumulation of tumor cells in non-breast tissue. While mechanistically complex, an emerging literature supports hemostatic elements as an important patient factor that facilitates the metastatic potential of breast cancer. Hemostatic elements involved include platelets, coagulation, and fibrinolysis. Key steps in breast tumor progression, including cellular transformation, proliferation, tumor cell survival, and angiogenesis, can be mediated by components of the hemostatic system. Thus, the hemostatic system provides potential targets for novel therapeutic approaches to breast cancer therapy with drugs in current use and in development. The present article provides a comprehensive overview of the evidence and mechanisms supporting the roles played by platelets, coagulation activation, and the fibrinolytic system in breast cancer progression.

The Robustness of Pathway Analysis in Identifying Potential Drug Targets in Non-Small Cell Lung Carcinoma

The identification of genes responsible for causing cancers from gene expression data has had varied success. Often the genes identified depend on the methods used for detecting expression patterns, or on the ways that the data had been normalized and filtered. The use of gene set enrichment analysis is one way to introduce biological information in order to improve the detection of differentially expressed genes and pathways. In this paper we show that the use of network models while still subject to the problems of normalization is a more robust method for detecting pathways that are differentially overrepresented in lung cancer data. Such differences may provide opportunities for novel therapeutics. In addition, we present evidence that non-small cell lung carcinoma is not a series of homogeneous diseases; rather that there is a heterogeny within the genotype which defies phenotype classification. This diversity helps to explain the lack of progress in developing therapies against non-small cell carcinoma and suggests that drug development may consider multiple pathways as treatment targets.

Drug repositioning discovery for early- and late-stage non-small-cell lung cancer

Drug repositioning is a popular approach in the pharmaceutical industry for identifying potential new uses for existing drugs and accelerating the development time. Non-small-cell lung cancer (NSCLC) is one of the leading causes of death worldwide. To reduce the biological heterogeneity effects among different individuals, both normal and cancer tissues were taken from the same patient, hence allowing pairwise testing. By comparing early- and late-stage cancer patients, we can identify stage-specific NSCLC genes. Differentially expressed genes are clustered separately to form up- and downregulated communities that are used as queries to perform enrichment analysis. The results suggest that pathways for early- and late-stage cancers are different. Sets of up- and downregulated genes were submitted to the cMap web resource to identify potential drugs. To achieve high confidence drug prediction, multiple microarray experimental results were merged by performing meta-analysis. The results of a few drug findings are supported by MTT assay or clonogenic assay data. In conclusion, we have been able to assess the potential existing drugs to identify novel anticancer drugs, which may be helpful in drug repositioning discovery for NSCLC.

Tissue factor in tumor microenvironment: a systematic review

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

TFPI1 mediates resistance to doxorubicin in breast cancer cells by inducing a hypoxic-like response

Thrombin and hypoxia are important players in breast cancer progression. Breast cancers often develop drug resistance, but mechanisms linking thrombin and hypoxia to drug resistance remain unresolved. Our studies using Doxorubicin (DOX) resistant MCF7 breast cancer cells reveals a mechanism linking DOX exposure with hypoxic induction of DOX resistance. Global expression changes between parental and DOX resistant MCF7 cells were examined. Westerns, Northerns and immunocytochemistry were used to validate drug resistance and differentially expressed genes. A cluster of genes involved in the anticoagulation pathway, with Tissue Factor Pathway Inhibitor 1 (TFPI1) the top hit, was identified. Plasmids overexpressing TFPI1 were utilized, and 1% O₂ was used to test the effects of hypoxia on drug resistance. Lastly, microarray datasets from patients with drug resistant breast tumors were interrogated for TFPI1 expression levels. TFPI1 protein levels were found elevated in 3 additional DOX resistant cells lines, from humans and rats, indicating evolutionarily conservation of the effect. Elevated TFPI1 in DOX resistant cells was active, as thrombin protein levels were coincidentally low. We observed elevated HIF1α protein in DOX resistant cells, and in cells with forced expression of TFPI1, suggesting TFPI1 induces HIF1α. TFPI1 also induced c-MYC, c-SRC, and HDAC2 protein, as well as DOX resistance in parental cells. Growth of cells in 1% O₂ induced elevated HIF1α, BCRP and MDR-1 protein, and these cells were resistant to DOX. Our in vitro results were consistent with in vivo patient datasets, as tumors harboring increased BCRP and MDR-1 expression also had increased TFPI1 expression. Our observations are clinically relevant indicating that DOX treatment induces an anticoagulation cascade, leading to inhibition of thrombin and the expression of HIF1α. This in turn activates a pathway leading to drug resistance.

Absence of tissue factor is characteristic of lymphoid malignancies of both T- and B-cell origin

BACKGROUND

Thrombosis is a marker of poor prognosis in individuals with solid tumors. The expression of tissue factor (TF) on the cell surface membrane of malignant cells is a pivotal molecular link between activation of coagulation, angiogenesis, metastasis, aggressive tumor behavior and poor survival. Interestingly, thrombosis is associated with shortened survival in solid, but not in lymphoid neoplasias.

OBJECTIVES

We sought to study whether the lack of impact of thrombosis on survival in lymphoid neoplasias could be due to a lack of tumor-derived TF expression.

METHODS

We analyzed TF gene (F3) expression in lymphoid (N=114), myeloid (N=49) and solid tumor (N=856) cell lines using the publicly available dataset from the Broad-Novartis Cancer Cell Line Encyclopedia (http://www.broadinstitute.org/ccle/home), and in 90 patient-derived lymphoma samples. TF protein expression was studied by immunohistochemistry (IHC).

RESULTS

In sharp contrast to wide F3 expression in solid tumors (74.2%), F3 was absent in all low and high grade T- and B-cell lymphomas, and in most myeloid tumors, except for select acute myeloid leukemias with monocytic component. IHC confirmed the absence of TF protein in all indolent and high-grade B-cell (0/90) and T-cell (0/20) lymphomas, and acute leukemias (0/11).

CONCLUSIONS

We show that TF in lymphomas does not derive from the malignant cells, since these do not express either F3 or TF protein. Therefore, it is unlikely that thrombosis in patients with lymphoid neoplasms is secondary to tumor-derived tissue factor.

Rationale for the design of an oncology trial using a generic targeted therapy multi‑drug regimen for NSCLC patients without treatment options (Review)

Despite more than 70 years of research concerning medication for cancer treatment, the disease still remains one of the leading causes of mortality worldwide. Many cancer types lead to death within a period of months to years. The original class of chemotherapeutics is not selective for tumor cells and often has limited efficacy, while treated patients suffer from adverse side‑effects. To date, the concept of tumor‑specific targeted therapy drugs has not fulfilled its expectation to provide a key for a cure. Today, many oncology trials are designed using a combination of chemotherapeutics with targeted therapy drugs. However, these approaches have limited outcomes in most cancer indications. This perspective review provides a rationale to combine targeted therapy drugs for cancer treatment based on observations of evolutionary principles of tumor development and HIV infections. In both diseases, the mechanisms of immune evasion and drug resistance can be compared to some extent. However, only for HIV is a breakthrough treatment available, which is the highly active antiretroviral therapy (HAART). The principles of HAART and recent findings from cancer research were employed to construct a hypothetical model for cancer treatment with a multi‑drug regimen of targeted therapy drugs. As an example of this hypothesis, it is proposed to combine already marketed targeted therapy drugs against VEGFRs, EGFR, CXCR4 and COX2 in an oncology trial for non‑small cell lung cancer patients without further treatment options.

Thromboembolic disease in patients with high-grade glioma

Venous thromboembolism (VTE) is common throughout the course of disease in high-grade glioma (HGG). The interactions between the coagulation cascade, endothelium, and regulation of angiogenesis are complex and drive glioblastoma growth and invasion. We reviewed the incidence of VTE in HGG, the biology of the coagulome as related to glioblastoma progression, prevention and treatment of thrombosis, and the putative role of anticoagulants as anti-cancer therapy. VTE can be significantly reduced during the postoperative period with adherence to the use of mechanical and medical thromboprophylaxis. Activation of the coagulation cascade occurs throughout the course of disease because of a variety of complex interactions, including tumor hypoxia, upregulation of VEGR expression, and increases in both tumor cell-specific tissue factor (TF) expression and inducible TF expression in numerous intrinsic regulatory pathways. Long-term anticoagulation to prevent VTE is an attractive therapy; however, the therapeutic window is narrow and current data do not support its routine use. Most patients with proven symptomatic VTE can be safely anticoagulated, including those receiving anti-VEGF therapy, such as bevacizumab. Initial therapy should include low molecular weight heparin (LMWH), and protracted anticoagulant treatment, perhaps indefinitely, is indicated for patients with HGG because of the ongoing risk of thrombosis. A variety of coagulation- and tumor-related proteins, such as TF and circulating microparticles, may serve as potential disease-specific biomarkers in relation to disease recurrence, monitoring of therapy, and as potential therapeutic targets.

Coagulation and metastasis: what does the experimental literature tell us?

Inhibition of coagulation greatly limits cancer metastasis in many experimental models. Cancer cells trigger coagulation, through expression of tissue factor or P-selectin ligands that have correlated with worse prognosis in human clinical studies. Cancer cells also affect coagulation through expression of thrombin and release of microparticles that augment coagulation. In the cancer-bearing host, coagulation facilitates tumour progression through release of platelet granule contents, inhibition of Natural Killer cells and recruitment of macrophages. We are revisiting this literature in the light of recent studies in which treatment of clinical cohorts with anticoagulant drugs led to diminished metastasis.

Classical and unconventional pathways of vesicular release in microglia

Emerging evidence indicates that activation of microglia, the immune cells of the brain, is strictly associated to both secretion of soluble molecules and release of extracellular membrane vesicles (EMVs) into the pericellular space. Through these processes, microglia heavily influence brain cell functions, either propagating inflammation and causing damage to neurons or playing a supportive, neuroprotective role. In this review, we highlight the emerging concepts related to vesicular mechanisms of secretion operating in microglial cells, with the aim of dissecting how microglia communicate with other cell types within the brain microenvironment in health and disease.

Coagulation and cancer: biological and clinical aspects

Malignancy affects the hemostatic system and the hemostatic system affects malignancy. In cancer patients there are a number of coagulation abnormalities which provide the background for an increased tendency of these patients to both thrombosis and hemorrhage. The causes of this coagulation impairment rely on general risk factors which are common to other categories of patients, and other factors which are specific to cancer, such as tumor type and disease stage. In addition, data from basic research indicate that the hemostatic components and the cancer biology are interconnected in multiple ways. Notably, while cancer cells are able to activate the coagulation system, the hemostatic factors play a role in tumor progression. This opens the way to the development of bifunctional therapeutic approaches that are both capable of attacking the malignant process and resolving the coagulation impairment. On the other hand, the management of thrombosis and hemorrhages in cancer patients can be different. To approach these problems, some guidelines have been released by prominent international scientific societies. Also actively investigated is the issue of identifying new biomarkers to classify the subjects at a higher risk, thus improving the prevention of thrombohemorrhagic events in these patients. Finally, novel prophylactic and therapeutic approaches are currently under development. This review provides an overview of the hemostatic complications in cancer, together with new insights into the interaction between hemostasis and cancer biology. We also review the assessment of the risk of thrombohemorrhagic events in cancer patients, and the prophylaxis and treatment of such manifestations.

International Society for Extracellular Vesicles: first annual meeting, April 17-21, 2012: ISEV-2012

Extracellular micro- and nano-scale membrane vesicles produced by different cells are recognised as an essential entity of physiological fluids in a variety of organisms and function as mediators of intercellular communication employed for the regulation of multiple systemic and local processes. In the last decade, an exponential amount of experimental work was dedicated to exploring the biogenesis and secretion mechanisms, physiological and pathological functions and potential applications of the extracellular vesicles (EVs). Noteworthy is the large heterogeneity of in vitro and in vivo models applied, technical approaches developed in these studies and the diversity of designations assigned to different or similar types of EVs. Hence, there is a clear necessity for a uniform nomenclature and standardisation of methods to isolate and characterise these vesicles. In April 2012, the first meeting of the International Society for Extracellular Vesicles (ISEV) took place bringing together this exponentially grown scientific community. The University of Gothenburg (Krefting Research Centre) together with the Interim Board of the Society created in September 2011 (Jan Lötvall, Clotilde Théry, Xandra Breakefield, Marca Wauben, Yong Song Gho, Lawrence Rajendran, Graça Raposo, Douglas Taylor, Margareta Sjöstrand and Esbjörn Telemo) organised this fantastic event that counted 488 registered and contributing participants. This meeting report provides a retrospective summary of the broad spectrum of ISEV-2012 sessions. Again, we emphasise novel findings, discussions and decisions met by the community during the meeting.