Coagulation factor VIIa-mediated protease-activated receptor 2 activation leads to β-catenin accumulation via the AKT/GSK3β pathway and contributes to breast cancer progression

FVIIa-PAR2 signaling facilitates immune escape by reducing phagocytic potential of macrophages in breast cancer

BACKGROUND

Treatment of breast cancers with immunotherapy has so far achieved limited success. Traditional immunotherapies focusing on cytotoxic T cells have attained modest success, while the approval of phagocytic checkpoint blockers is still pending. Coagulation proteases are crucial to cancer growth and proliferation, but their relevance in altering the immunologic topography in tumors remains largely unknown.

OBJECTIVES

In this study, we aimed to examine whether factor VIIa (FVIIa)-driven protease-activated receptor 2 (PAR2) activation and its subsequent signaling pathways assist cancer cells in evading phagocytic macrophages.

METHODS

Peripheral blood mononuclear cell- or THP-1-derived macrophages were cocultured with MDA-MB-468 cells that were pretreated with or without FVIIa. The phagocytic activity of macrophages was assessed through flow cytometry and immunofluorescence. Additionally, an allograft model using wild-type and PAR2-deleted 4T1 cells was employed to investigate the impact of PAR2 activation on immune escape from macrophages in vivo.

RESULTS

We found evidence that FVIIa-induced PAR2 cleavage activates downstream signaling cascades and augments cellular levels of microRNA221, which transcriptionally activates both CD47 and stanniocalcein 1 expression, thereby assisting the escape from phagocytosis by macrophages. Stanniocalcein 1 decreases the surface expression of calreticulin, a dominant prophagocytic signal, thereby tilting it in favor of phagocytic evasion. Mouse models using PAR2-depleted cells displayed smaller tumor volumes and corresponding greater phagocytic events when combined with anti-CD47/anti-PD-L1 antibodies.

CONCLUSION

PAR2 signaling initiates an intrinsic mechanism of immune escape by diminishing phagocytosis of cancer cells.

Coagulation Protease-Driven Cancer Immune Evasion: Potential Targets for Cancer Immunotherapy

Blood coagulation and cancer are intrinsically connected, hypercoagulation-associated thrombotic complications are commonly observed in certain types of cancer, often leading to decreased survival in cancer patients. Apart from the common role in coagulation, coagulation proteases often trigger intracellular signaling in various cancers via the activation of a G protein-coupled receptor superfamily protease: protease-activated receptors (PARs). Although the role of PARs is well-established in the development and progression of certain types of cancer, their impact on cancer immune response is only just emerging. The present review highlights how coagulation protease-driven PAR signaling plays a key role in modulating innate and adaptive immune responses. This is followed by a detailed discussion on the contribution of coagulation protease-induced signaling in cancer immune evasion, thereby supporting the growth and development of certain tumors. A special section of the review demonstrates the role of coagulation proteases, thrombin, factor VIIa, and factor Xa in cancer immune evasion. Targeting coagulation protease-induced signaling might be a potential therapeutic strategy to boost the immune surveillance mechanism of a host fighting against cancer, thereby augmenting the clinical consequences of targeted immunotherapeutic regimens.

Coagulation factor VIIa enhances programmed death-ligand 1 expression and its stability in breast cancer cells to promote breast cancer immune evasion

BACKGROUND

Immunotherapy for breast cancer has not gained significant success. Coagulation factor VIIa (FVIIa)-tissue factor (TF) mediated activation of protease-activated receptor 2 (PAR2) is shown to promote metastasis and secretion of the immune-modulatory cytokines but the role of FVIIa in cancer immunology is still not well understood.

OBJECTIVES

Here, we aim to investigate whether FVIIa protects breast cancer cells from CD8 T-cell-mediated killing.

METHODS

Peripheral blood mononuclear cell-derived CD8 T cells were cocultured with vehicle or FVIIa pretreated MDAMB468 cells. The proliferation and activity of CD8 T cells were measured by flow cytometry and ELISA. An allograft model, using wild-type or TF/PAR2-deleted 4T1 cells, was employed to determine the effect of FVIIa on breast cancer immune evasion in vivo.

RESULTS

Here, we demonstrate that TF-FVIIa induces programmed death-ligand 1 (PD-L1) in breast cancer cells by activating PAR2. PAR2 activation triggers large tumor suppressor kinase 1 (LATS1) inactivation leading to loss of yes-associated protein (YAP)/transcriptional coactivator with PDZ-binding motif (TAZ) phosphorylation and subsequent nuclear localization of YAP/TAZ. YAP/TAZ inhibition reduces PD-L1 expression and increases CD8 T-cell activity. We further demonstrate that, apart from transcriptional induction of PD-L1, PAR2 activation also increases PD-L1 stability by enhancing its glycosylation through N-glycosyltransferases STT3A and STT3B.

CONCLUSION

In a mouse model of breast cancer, tumor cell-specific PAR2 depletion leads to PD-L1 downregulation and increases anti-PD-1 immunotherapy efficacy. In conclusion, we showed that FVIIa-mediated signaling cascade in cancer cells serves as a tumor intrinsic mechanism of immunosuppression to promote cancer immune evasion.

CIP2A interacts with AKT1 to promote the malignant biological behaviors of oral squamous cell carcinoma by upregulating the GSK‑3β/β‑catenin pathway

Oral squamous cell carcinoma (OSCC) is one of the most common malignancies worldwide, which is associated with a poor prognosis. The present study aimed to investigate the role of cancerous inhibitor of protein phosphatase 2A (CIP2A) in OSCC and its regulatory effect on AKT1. Firstly, CIP2A and AKT1 expression in OSCC cells was detected by western blotting. After silencing CIP2A, cell viability and cell proliferation were assessed using the Cell Counting Kit-8 assay and 5-ethynyl-2'-deoxyuridine staining. Cell apoptosis was evaluated by TUNEL staining and the expression of apoptosis-related proteins was assessed using western blotting. Wound healing, Transwell and tube formation assays were performed to evaluate CAL-27 cell migration, invasion and human umbilical vein endothelial cell (HUVEC) tube formation. The interaction between CIP2A and AKT1 was identified by co-immunoprecipitation (co-IP). In addition, AKT1 was overexpressed in CIP2A-silenced CAL-27 cells to perform rescue experiments to analyze the malignant biological functions of CAL-27 cells. Finally, the expression of proteins in the glycogen synthase kinase (GSK)-3β/β-catenin pathway was determined by western blot analysis. Markedly elevated CIP2A and AKT1 expression was observed in OSCC cells. CIP2A knockdown inhibited the viability, proliferation, migration and invasion, and promoted the apoptosis of CAL-27 cells. Concurrently, CIP2A loss-of-function attenuated tube formation. Results of Co-IP confirmed there was an interaction between CIP2A and AKT1. Rescue experiments suggested that AKT1 overexpression alleviated the inhibitory effects of CIP2A knockdown on the viability, proliferation, migration and invasion of CAL-27 cells, as well as tube formation in HUVECs . Additionally, CIP2A silencing significantly downregulated phosphorylated-GSK-3β and β-catenin expression, which was reversed by AKT1 overexpression. In conclusion, CIP2A could interact with AKT1 to promote the malignant biological behaviors of OSCC cells by upregulating the GSK-3β/β-catenin pathway. These findings may provide a targeted therapy for OSCC treatment.

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.

Matrix metalloproteinases as therapeutic targets in breast cancer

Matrix metalloproteinases (MMPs) are the most prominent proteinases involved in tumorigenesis. They were initially recognized to promote tumor progression by remodeling the extracellular matrix through their proteolytic activity. However, accumulating evidence has revealed that some MMPs have protective roles in cancer progression, and the same MMP can exert opposing roles depending on the cell type in which it is expressed or the stage of cancer. Moreover, studies have shown that MMPs are involved in cancer progression through their roles in other biological processes such as cell signaling and immune regulation, independent of their catalytic activity. Despite the prognostic significance of tumoral or stromal expression of MMPs in breast cancer, their roles and molecular mechanisms in breast cancer progression remain unclear. As the failures of early clinical trials with broad-spectrum MMP inhibitors were mainly due to a lack of drug specificity, substantial efforts have been made to develop highly selective MMP inhibitors. Some recently developed MMP inhibitory monoclonal antibodies demonstrated promising anti-tumor effects in preclinical models of breast cancer. Importantly, anti-tumor effects of these antibodies were associated with the modulation of tumor immune microenvironment, suggesting that the use of MMP inhibitors in combination with immunotherapy can improve the efficacy of immunotherapy in HER2-positive or triple-negative breast cancer. In this review, the current understanding of the roles of tumoral or stromal MMPs in breast cancer is summarized, and recent advances in the development of highly selective MMP inhibitors are discussed.

Elucidation of the signalling pathways for enhanced exosome release from Mycobacterium-infected macrophages and subsequent induction of differentiation

Exosomes are extracellular vesicles released by all cell types; perform several important functions such as cell-to-cell communication, growth, differentiation and so on. Exosomes elicit several signalling mechanisms as they carry information in the form of DNA, RNA or protein docked on them. We show that exosomes released from Mycobacterium tuberculosis (Mtb)-infected macrophages not only induce differentiation of naïve monocytes but also generate functionally active macrophages via MAPK-dependent signalling mechanism through MK-2 and NF-κβ activation which is completely different from the differentiation induced by exosomes from uninfected macrophages. Further, we elucidate unequivocally the signalling mechanism behind the enhanced release of exosome generation from infected macrophages driven by AKT phosphorylation involving Rab7a and Rab11a. Genes of both ESCRT-dependent and -independent pathways are found to be involved in enhanced exosomes release and are modulated by AKT. However, interestingly, the genes of the ESCRT-independent pathway are dependent on NF-κβ activation while the genes of the dependent pathway are not, suggesting two parallel signalling cascades operating in tandem.

Tissue factor: a neglected role in cancer biology

Tissue factor (TF), an initiator of extrinsic coagulation pathway, is positively correlated with venous thromboembolism (VTE) of tumor patients. Beyond thrombosis, TF plays a vital role in tumor progression. TF is highly expressed in cancer tissues and circulating tumor cell (CTC), and activates factor VIIa (FVIIa), which increases tumor cells proliferation, angiogenesis, epithelial-mesenchymal transition (EMT) and cancer stem cells(CSCs) activity. Furthermore, TF and TF-positive microvesicles (TF⁺MVs) activate the coagulation system to promote the clots formation with non-tumor cell components (e.g., platelets, leukocytes, fibrin), which makes tumor cells adhere to clots to form CTC clusters. Then, tumor cells utilize clots to cause its reducing fluid shear stress (FSS), anoikis resistance, immune escape, adhesion, extravasation and colonization. Herein, we review in detail that how TF signaling promotes tumor metastasis, and how TF-targeted therapeutic strategies are being in the preclinical and clinical trials.

Antiproliferative Effect of Grammatophyllum speciosum Ethanolic Extract and Its Bioactive Compound on Human Breast Cancer Cells

Background/Aim. Grammatophyllum speciosum Blume exhibits various promising pharmacological activities. However, its effect on breast cancer has not been determined. Materials and Methods. The antiproliferation effects of the G. speciosum pseudobulb ethanolic extract (GSE) and isovitexin (bioactive constituent) were investigated on the MCF-7 human breast cancer cell line using MTT and colony formation assay. The expression levels of proliferation-regulatory proteins were determined by western blotting. Results. Noncytotoxic concentrations of GSE significantly suppressed the proliferation of MCF-7 cells. Tumor colony formation decreased in both number and size. The level of phosphorylated AKT and β-catenin was suppressed by GSE treatment. Antiproliferation was observed in isovitexin-treated MCF-7 cells in the form of inhibited colony formation and reduced expression of phosphorylated AKT and β-catenin protein. Conclusions. This study demonstrates the novel effect of G. speciosum as an antiproliferative via suppression of the AKT/β-catenin-dependent pathway. This may prompt further investigation of this plant in breast cancer therapy.

GPCR Partners as Cancer Driver Genes: Association with PH-Signal Proteins in a Distinctive Signaling Network

The essential role of G-protein coupled receptors (GPCRs) in tumor growth is recognized, yet a GPCR based drug in cancer is rare. Understanding the molecular path of a tumor driver gene may lead to the design and development of an effective drug. For example, in members of protease-activated receptor (PAR) family (e.g., PAR1 and PAR2), a novel PH-binding motif is allocated as critical for tumor growth. Animal models have indicated the generation of large tumors in the presence of PAR1 or PAR2 oncogenes. These tumors showed effective inhibition when the PH-binding motif was either modified or were inhibited by a specific inhibitor targeted to the PH-binding motif. In the second part of the review we discuss several aspects of some cardinal GPCRs in tumor angiogenesis.

Development and Validation of a Practical Prognostic Coagulation Index for Patients with Esophageal Squamous Cell Cancer

BACKGROUND

This study aimed to establish an effective and practical prognostic index for esophageal squamous cell cancer (ESCC) based on the coagulation factors.

METHODS

The training cohort of 965 patients with ESCC was retrospectively collected at Sichuan Cancer Hospital from 2012 to 2014, along with clinical characteristics and follow-up information. Risk factors of coagulation status, including 11 blood parameters (platelet [PLT], mean platelet volume [MPV], platelet distribution width [PDW], plateletocrit [PCT], thrombin time [TT], prothrombin time [PT], international normalized ratio [INR], activated partial thromboplastin time [APTT], fibrinogen, D-dimer, and fibrinogen degradation product [FDP]), were studied by least absolute shrinkage and selection operator (LASSO) Cox regression and the Coagulation Index was established. The index was validated in a cohort of 848 patients with ESCC at the same institution, from 2015 to 2016.

RESULTS

Three variables of PLT, MPV, and fibrinogen were identified by selecting features with coefficients in the LASSO algorithm, and a Coagulation Index was established as follows: Coagulation Index = 0.0005 × PLT (10⁹/L) - 0.0384 × MPV (fL) + 0.1148 × fibrinogen (g/L). A higher Coagulation Index score was significantly associated with higher pT stage and pN stage (p < 0.05). With this prognostic index, patients could be stratified into three risk groups. The 3-year overall survival (OS) rates of the low-, middle- and high-risk groups in the training cohort were 63.5%, 55.5% and 43.1%, respectively (log-rank p < 0.001). Similarly, in the validation set, the respective 3-year OS for each risk group was significantly different across the three risk groups. Multivariate analysis indicated that the Coagulation Index remained a significant factor for predicting OS, independently of pathological TNM stage.

CONCLUSIONS

The Coagulation Index is an independent predictor of survival for patients with ESCC.

Solasodine, Isolated from Solanum sisymbriifolium Fruits, Has a Potent Anti-Tumor Activity Against Pancreatic Cancer

BACKGROUND

Increasing evidences have revealed that solasodine, isolated from Solanum sisymbriifolium fruits, has multiple functions such as anti-oxidant, anti-tumor and anti-infection. However, its role in pancreatic cancer has not been well studied.

METHODS

To explore the role of solasodine in pancreatic cancer, human pancreatic cell lines including SW1990 and PANC1 were treated with different concentrations of solasodine for 48 h, and cell viability was evaluated by MTT assay, cell invasion and migration were evaluated by Transwell assay. The effect of solasodine on the apoptosis of SW1990 and PANC1 cells was detected by flow cytometry. To further explore the antitumor effect of solasodine in vivo, an SW1990 tumor-bearing mouse model was constructed. The effects of solasodine on cytokines in the serum of SW1990 tumor-bearing mice were also evaluated by ELISA assay.

RESULTS

Specifically, in vitro, solasodine could significantly inhibit the proliferation of pancreatic cancer cell lines SW1990 and PANC1 cells. Flow cytometric analysis indicated that solasodine could induce apoptosis of SW1990 and PANC1 cells. Western blot assay indicated that solasodine could significantly inhibit the activation of Cox-2/Akt/GSK3β signal pathway. Meanwhile, the release of Cytochrome c from mitochondria to cytoplasm which can raise the caspases cascade (C-caspase 3 and C-caspase 9) was significantly enhanced by solasodine. In vivo, the results showed that solasodine had potent anti-tumor activities with a lower cytotoxicity. In addition, the serum TNF-α, IL-2 and IFN-γ levels in SW1990 tumor-bearing mice after the treatment of solasodine was significantly increased.

CONCLUSION

Taken together, our results suggested that the solasodine could prevent the progression of pancreatic cancer by inhibiting proliferation and promoting apoptosis, as well as stimulating immunity, suggesting that solasodine might be a potential therapeutic strategy for pancreatic cancer.

Platelets, immune cells and the coagulation cascade; friend or foe of the circulating tumour cell?

Cancer cells that transit from primary tumours into the circulatory system are known as circulating tumour cells (CTCs). These cancer cells have unique phenotypic and genotypic characteristics which allow them to survive within the circulation, subsequently extravasate and metastasise. CTCs have emerged as a useful diagnostic tool using "liquid biopsies" to report on the metastatic potential of cancers. However, CTCs by their nature interact with components of the blood circulatory system on a constant basis, influencing both their physical and morphological characteristics as well as metastatic capabilities. These properties and the associated molecular profile may provide critical diagnostic and prognostic capabilities in the clinic. Platelets interact with CTCs within minutes of their dissemination and are crucial in the formation of the initial metastatic niche. Platelets and coagulation proteins also alter the fate of a CTC by influencing EMT, promoting pro-survival signalling and aiding in evading immune cell destruction. CTCs have the capacity to directly hijack immune cells and utilise them to aid in CTC metastatic seeding processes. The disruption of CTC clusters may also offer a strategy for the treatment of advance staged cancers. Therapeutic disruption of these heterotypical interactions as well as direct CTC targeting hold great promise, especially with the advent of new immunotherapies and personalised medicines. Understanding the molecular role that platelets, immune cells and the coagulation cascade play in CTC biology will allow us to identify and characterise the most clinically relevant CTCs from patients. This will subsequently advance the clinical utility of CTCs in cancer diagnosis/prognosis.

TSG101 Promotes the Proliferation, Migration, and Invasion of Human Glioma Cells by Regulating the AKT/GSK3β/β-Catenin and RhoC/Cofilin Pathways

The tumor susceptibility gene 101 (TSG101) has been reported to play important roles in the development and progression of several human cancers, such as pancreatic cancer, prostate cancer, and hepatocellular carcinoma. However, its potential roles and underlined mechanisms in human glioma are still needed to be further clarified. This study was designed to assess the expression of TSG101 in glioma patients and its effects on glioma cell proliferation, migration, and invasion. Publicly available data revealed that TSG101 mRNA was significantly upregulated in glioma tissues, and high levels of TSG101 were associated with poor prognosis in glioma patients. Western blot and immunohistochemistry experiments further showed that the expression level of TSG101 protein was significantly upregulated in glioma patients, especially in the patients with high-grade glioma. The functional studies showed that knockdown of TSG101 suppressed the proliferation, migration, and invasion of glioma cells, while overexpression of TSG101 facilitated them. Mechanistic studies indicated that the proliferation, migration, and invasion induced by TSG101 in human glioma were related to AKT/GSK3β/β-catenin and RhoC/Cofilin signaling pathways. In conclusion, the above results suggest that the expression of TSG101 is elevated in glioma patients, which accelerates the proliferation, migration, and invasion of glioma cells by regulating the AKT/GSK3β/β-catenin and RhoC/Cofilin pathways.

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.

AKT/GSK-3β/β-catenin signaling pathway participates in erythropoietin-promoted glioma proliferation

PURPOSE

Although erythropoietin (EPO) has been proven to significantly promote the proliferation of cancer cells, the mechanism for promoting glioma proliferation is poorly understood. Here, we examined the functional role of the AKT/GSK-3β/β-catenin signaling pathway in the EPO-mediated proliferation of glioma.

METHODS

The distribution of EPO and Ki-67 among clinical samples with different WHO grades was plotted by Immunological Histological Chemistry analysis. U87 and U251 glioma cell lines were treated with short hairpin RNA targeting (shEPO), recombinant human erythropoietin (rhEPO) and/or AKT-specific inhibitor (MK-2206). The changes in phosphorylated AKT, nuclear β-catenin, cyclin D1 and p27kip1 expression were detected. Cell cycle distributions and glioma proliferation in vitro and in vivo were analyzed.

RESULTS

The expression level of EPO was significantly elevated with the increase of WHO grade and Ki67 in clinical glioma specimens. In vitro, knockdown of endogenous EPO in U87 and U251 cells effectively block the phosphorylation of AKT and GSK-3β and the expression of nuclear β-catenin. shEPO treatment also significantly decreased the expression of cyclin D1 and increased the expression of p27kip1. The cell cycle transition then slowed down and the proliferation of glioma cells or mouse xenograft tumors both decreased. Treatment of cells or tumors with extra rhEPO reversed the above biological effects mediated by shEPO. rhEPO-induced activation of the AKT/GSK-3β/β-catenin pathway and proliferation were abolished by MK-2206.

CONCLUSIONS

Our study identified the AKT/GSK-3β/β-catenin axis as a critical mediator of EPO-induced glioma proliferation and further provided a clinically significant dimension to the biology of EPO.

Triple-negative breast cancer-derived microvesicles transfer microRNA221 to the recipient cells and thereby promote epithelial-to-mesenchymal transition

The triple-negative phenotype is the most prevalent form of human breast cancer worldwide and is characterized by poor survival, high aggressiveness, and recurrence. Microvesicles (MV) are shredded plasma membrane components and critically mediate cell-cell communication, but can also induce cancer proliferation and metastasis. Previous studies have revealed that protease-activated receptor 2 (PAR2) contributes significantly to human triple-negative breast cancer (TNBC) progression by releasing nano-size MV and promoting cell proliferation, migration, and invasion. MV isolated from highly aggressive human TNBC cells impart metastatic potential to nonmetastatic cells. Over-expression of microRNA221 (miR221) has also been reported to enhance the metastatic potential of human TNBC, but miR221's relationship to PAR2-induced MV is unclear. Here, using isolated MV, immunoblotting, quantitative RT-PCR, FACS analysis, and enzymatic assays, we show that miR221 is translocated via human TNBC-derived MV, which upon fusion with recipient cells, enhance their proliferation, survival, and metastasis both in vitro and in vivo by inducing the epithelial-to-mesenchymal transition (EMT). Administration of anti-miR221 significantly impaired MV-induced expression of the mesenchymal markers Snail, Slug, N-cadherin, and vimentin in the recipient cells, whereas restoring expression of the epithelial marker E-cadherin. We also demonstrate that MV-associated miR221 targets phosphatase and tensin homolog (PTEN) in the recipient cells, followed by AKT Ser/Thr kinase (AKT)/NF-κB activation, which promotes EMT. Moreover, elevated miR221 levels in MV derived from human TNBC patients' blood could induce cell proliferation and metastasis in recipient cells. In summary, miR221 transfer from TNBC cells via PAR2-derived MV induces EMT and enhances the malignant potential of recipient cells.

Bronchoalveolar lavage cell profiles and proteins concentrations can be used to phenotype extrinsic allergic alveolitis patients

Background

Extrinsic allergic alveolitis (EAA) patients form heterogenous group with different clinical manifestation and different prognosis. We aimed to determine how to phenotype distinct EAA subgroups. Predictive role of the bronchoalveolar lavage fluid (BALF) IL-4Rα concentration at the time of diagnosis with regard to the clinical behavior in EAA patients was studied.

Methods

Concentrations of MMP-7, IL-4Rα, TNF-α, and PAR-2 were measured in the BALF od 71 EAA patients at the time of diagnosis. Lung functions and outcome data were assessed at 12 months after the diagnosis. Correlations between the BALF protein concentration, cell profile, lung functions and patient outcome were determined.

Results

We found positive correlations between BALF IL-4Rα concentration and BALF eosinophils (p = 0,006), negative correlation between IL-4Rα BALF concentration and diffusing capacity (DLco) (p = 0,003), negative correlation between IL-4Rα BALF concentration and forced vital capacity (FVC) (p = 0,004) and negative correlation between IL-4Rα concentration and BALF lymphocytes (p = 0,04). The BALF concentration of IL-4Rα was significantly higher in acute exacerbation patients (p = 0,0032) and in patients progressing despite corticosteroid treatment (p = 0,04). We observed a positive correlation between MMP-7 BALF concentration and the BALF lymphocytes (p = 0.05), negative correlation between the PAR-2 BALF concentration and DLco (p = 0.04) and a negative correlation between the BALF TNF-α concentration and DLco (p = 0.03).

Conclusions

Specific subgroup of EAA patients with more severe functional impact, distinct BALF cell profile and higher IL-4Rα BALF concentration can be differentiated. Correlations between the BALF concentrations of PAR-2, MMP-7 and TNF-α with clinical parameters may reflect the role of inflammation in the pathogenesis of EAA.

PAR-2 promotes invasion and migration of esophageal cancer cells by activating MEK/ERK and PI3K/Akt signaling pathway

Protease-activated receptor 2 (PAR-2) has been demonstrated to promote invasion and metastasis of certain cancer cells. This study aimed to investigate the mechanism by which PAR-2 regulated invasion and migration of esophageal cancer (EC) cells EC109. A successfully constructed PAR-2 shRNA lentiviral vector (Lenti-PAR-2 shRNA) was stably transfected into EC109 cells, and the expression of PAR-2 in infected cells was detected by quantitative real-time PCR (qRT-PCR) and western blotting. Specific inhibitors, PD98059 (for MEK/ERK) and LY294002 (for PI3K/Akt), were used to confirm the role of MEK/ERK and PI3K/Akt signaling pathways, respectively, in PAR-2-regulated invasion and migration of EC109 cells. A significant decrease in PAR-2 mRNA and protein expression was detected in EC109 cells stably transfected with Lenti-PAR-2 shRNA. The PAR-2 agonist could dramatically promote cell invasion and migration, up-regulate the expression of MMP-9 and TM4SF3, and activate MEK/ERK and PI3K/Akt signaling pathways. However, PAR-2 gene silencing attenuated PAR-2-mediated enhancement of invasion and migration of EC109 cells, significantly down-regulated the mRNA and protein expression of MMP-9 and TM4SF3, and inhibited ERK (Try202/204) and Akt (Ser473) phosphorylation. An effect similar to PAR-2 silencing could be achieved with the two specific MEK/ERK and PI3K/Akt pathway inhibitors. Consequently, these results demonstrated that PAR-2 promoted invasion and migration of esophageal cancer cells EC109 by activating MEK/ERK and PI3K/Akt signaling pathways, which was accompanied by up-regulation of MMP-9 and TM4SF3 expression. Hence, PAR-2 may be a potential candidate for anti-metastasis treatment of EC.

Molecular targets of curcumin in breast cancer (Review)

Curcumin (diferuloylmethane), an orange‑yellow component of turmeric or curry powder, is a polyphenol natural product isolated from the rhizome of Curcuma longa. For centuries, curcumin has been used in medicinal preparations and as a food colorant. In recent years, extensive in vitro and in vivo studies have suggested that curcumin possesses activity against cancer, viral infection, arthritis, amyloid aggregation, oxidation and inflammation. Curcumin exerts anticancer effects primarily by activating apoptotic pathways in cancer cells and inhibiting pro‑cancer processes, including inflammation, angiogenesis and metastasis. Curcumin targets numerous signaling pathways associated with cancer therapy, including pathways mediated by p53, Ras, phosphatidylinositol‑3‑kinase, protein kinase B, Wnt‑β catenin and mammalian target of rapamycin. Clinical studies have demonstrated that curcumin alone or combined with other drugs exhibits promising anticancer activity in patients with breast cancer without adverse effects. In the present review, the chemistry and bioavailability of curcumin and its molecular targets in breast cancer are discussed. Future research directions are discussed to further understand this promising natural product.

Tenascin-C Modulates Cell Cycle Progression to Enhance Tumour Cell Proliferation through AKT/FOXO1 Signalling in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is a disease with an extremely poor prognosis that is characterized by a rich extracellular matrix (ECM). Tenascin-C (TNC) is a component of the ECM and plays a role in tumour progression. In this study, we reported that TNC is overexpressed in PDAC tissues and is correlated with tumour stage and cyclin D1 expression. Cyclin D1 is key regulator of the cell cycle G1/S transition. Further experiments revealed that TNC promotes G1/S transition through AKT signalling. TNC/AKT increases the expression of cyclin D1 by enhancing the transcriptional activity of β-catenin, whereas the translocation of FOXO1 from the nucleus results in the downregulation of p27^Kip1. Cyclin D1 and p27^Kip1 regulate the activity of cyclin D1-CDK4 complexes and retinoblastoma (Rb), and then they stimulate the progression of G1/S transition and tumour cell proliferation. In conclusion, TNC exerts its activating effect on the proliferation of pancreatic cancer cells in vitro and in vivo through its functional target AKT/FOXO1/β-catenin. The molecular mechanisms that drive PDAC progression will be useful for the development of molecular markers and the evaluation of patient prognosis.

Tissue factor at the crossroad of coagulation and cell signaling

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

Tissue factor: newer concepts in thrombosis and its role beyond thrombosis and hemostasis

For many years, the attention on tissue factor (TF) in human pathophysiology has been limited to its role as initiator of extrinsic coagulation pathway. Moreover, it was described as a glycoprotein located in several tissue including vascular wall and atherosclerotic plaque. However, in the last two decades, the discovery that TF circulates in the blood as cell-associated protein, microparticles (MPs) bound and as soluble form, is changing this old vessel-wall TF dogma. Moreover, it has been reported that TF is expressed by different cell types, even T lymphocytes and platelets, and different pathological conditions, such as acute and chronic inflammatory status, and cancer, may enhance its expression and activity. Thus, recent advances in the biology of TF have clearly indicated that beyond its known effects on blood coagulation, it is a "true surface receptor" involved in many intracellular signaling, cell-survival, gene and protein expression, proliferation, angiogenesis and tumor metastasis. Finally, therapeutic modulation of TF expression and/or activity has been tested with controversial results. This report, starting from the old point of view about TF as initiator of extrinsic coagulation pathway, briefly illustrates the more recent concepts about TF and thrombosis and finally gives an overview about its role beyond thrombosis and haemostasis focusing on the different intracellular mechanisms triggered by its activation and potentially involved in atherosclerosis.

The Protease Activated Receptor2 Promotes Rab5a Mediated Generation of Pro-metastatic Microvesicles

Metastasis, the hallmark of cancer propagation is attributed by the modification of phenotypic/functional behavior of cells to break attachment and migrate to distant body parts. Cancer cell-secreted microvesicles (MVs) contribute immensely in disease propagation. These nano-vesicles, generated from plasma membrane outward budding are taken up by nearby healthy cells thereby inducing phenotypic alterations in those recipient cells. Protease activated receptor 2 (PAR2), activated by trypsin, also contributes to cancer progression by increasing metastasis, angiogenesis etc. Here, we report that PAR2 activation promotes pro-metastatic MVs generation from human breast cancer cell line, MDA-MB-231. Rab5a, located at the plasma membrane plays vital roles in MVs biogenesis. We show that PAR2 stimulation promotes AKT phosphorylation which activates Rab5a by converting inactive Rab5a-GDP to active Rab5a-GTP. Active Rab5a polymerizes actin which critically regulates MVs shedding. Not only MVs generation, has this Rab5a activation also promoted cell migration and invasion. We reveal that Rab5a is over-expressed in human breast tumor specimen and contributes MVs generation in those patients. The involvement of p38 MAPK in MVs-induced cell metastasis has also been highlighted in the present study. Blockade of Rab5a activation can be a potential therapeutic approach to restrict MVs shedding and associated breast cancer metastasis.

Tissue factor as a mediator of coagulation and signaling in cancer and chronic inflammation

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