Antimetastatic activities of heparins and modified heparins. Experimental evidence

Cancer-associated venous thromboembolism: a comprehensive review

It has been 200 years since the first case of cancer-associated thrombosis (CAT) was reported. Venous thromboembolism (VTE) remains a leading cause of morbidity and mortality in cancer patients. Malignant tumors interact with the coagulation system in complex ways. CAT continues to pose a significant challenge in clinical practice. The risk factors for CAT are complex and multifactorial, primarily including patient, cancer, and therapy-related factors. We have introduced assessment models for CAT and bleeding risk, but the performance of these models has been less than satisfactory. Currently, the main anticoagulant drugs for treating CAT include vitamin K antagonists (VKAs), low molecular weight heparin (LMWH), and direct oral anticoagulants (DOACs). We have provided a detailed overview of the advantages and disadvantages of these three types of drugs and suggestions on choosing the appropriate type of medication for different clinical scenarios. CAT incidence, pathophysiology, risk factors, risk prediction models, and recent advancements in treatment and management are summarized in this review.

Towards an emerging role for anticoagulants in cancer therapy: a systematic review and meta-analysis

Background

Anticoagulants, renowned for their role in preventing blood clot formation, have captivated researchers' attention for the exploitation of their potential to inhibit cancer in pre-clinical models.

Objectives

To undertake a systematic review and meta-analysis of the effects of anticoagulants in murine cancer research models. Further, to present a reference tool for anticoagulant therapeutic modalities relating to future animal pre-clinical models of cancer and their translation into the clinic.

Methods

Four databases were utilized including Medline (Ovid), Embase (Ovid), Web of science, and Scopus databases. We included studies relating to any cancer conducted in murine models that assessed the effect of traditional anticoagulants (heparin and its derivatives and warfarin) and newer oral anticoagulants on cancer.

Results

A total of 6,158 articles were identified in an initial multi-database search. A total of 157 records were finally included for data extraction. Studies on heparin species and warfarin demonstrated statistically significant results in favour of tumour growth and metastasis inhibition.

Conclusion

Our findings constitute a valuable reference guide for the application of anticoagulants in cancer research and explore the promising utilization of non-anticoagulants heparin in preclinical cancer research.

Systematic Review Registration

PROSPERO [CRD42024555603].

Potential effects of anticoagulants in preclinical mice models of oral cancer: A systematic review

Oral squamous cell carcinoma (OSCC) is the most common head and neck cancer. There is mounting evidence to suggest that several components of the coagulation system directly affect carcinogenesis. Our recent in vitro studies demonstrated, for the first time, that various anticoagulants have anticancer effects on OSCC. They also showed the need for the immediate translation of these experimental conditions from bench to preclinical animal models. Here, we carried out a systematic review to summarise existing evidence on murine models built around the interactions between anticoagulants and oral cancer. Only one preclinical murine study was included in our systematic review, investigating the role of heparins in tumour pathophysiology. The paucity of evidence regarding the interactions between oral squamous cell carcinoma and anticoagulants emphasises the urgency with which further preclinical research should be conducted.

Evolving perspectives in reverse cardio-oncology: A review of current status, pathophysiological insights, and future directives

Cardiovascular disease (CVD) and cancer are leading causes of mortality worldwide, traditionally linked through adverse effects of cancer therapies on cardiovascular health. However, reverse cardio-oncology, a burgeoning field, shifts this perspective to examine how cardiovascular diseases influence the onset and progression of cancer. This novel approach has revealed a higher likelihood of cancer development in patients with pre-existing cardiovascular conditions, attributed to shared risk factors such as obesity, a sedentary lifestyle, and smoking. Underlying mechanisms like chronic inflammation and clonal hematopoiesis further illuminate the connections between cardiovascular ailments and cancer. This comprehensive narrative review, spanning a broad spectrum of studies, outlines the syndromic classification of cardio-oncology, the intersection of cardiovascular risk factors and oncogenesis, and the bidirectional dynamics between CVD and cancer. Additionally, the review also discusses the pathophysiological mechanisms underpinning this interconnection, examining the roles of cardiokines, genetic factors, and the effects of cardiovascular therapies and biomarkers in cancer diagnostics. Lastly, it aims to underline future directives, emphasising the need for integrated healthcare strategies, interdisciplinary research, and comprehensive treatment protocols.

Non-Anticoagulant Activities of Low Molecular Weight Heparins-A Review

Low molecular weight heparins (LMWHs) are derived from heparin through chemical or enzymatic cleavage with an average molecular weight (Mw) of 2000-8000 Da. They exhibit more selective activities and advantages over heparin, causing fewer side effects, such as bleeding and heparin-induced thrombocytopenia. Due to different preparation methods, LMWHs have diverse structures and extensive biological activities. In this review, we describe the basic preparation methods in this field and compare the main principles and advantages of these specific methods in detail. Importantly, we focus on the non-anticoagulant pharmacological effects of LMWHs and their conjugates, such as preventing glycocalyx shedding, anti-inflammatory, antiviral infection, anti-fibrosis, inhibiting angiogenesis, inhibiting cell adhesion and improving endothelial function. LMWHs are effective in various diseases at the animal level, including cancer, some viral diseases, fibrotic diseases, and obstetric diseases. Finally, we briefly summarize their usage and potential applications in the clinic to promote the development and utilization of LMWHs.

Heparins are potent inhibitors of ectonucleotide pyrophosphatase/phospho-diesterase-1 (NPP1) - a promising target for the immunotherapy of cancer

Introduction

Heparins, naturally occurring glycosaminoglycans, are widely used for thrombosis prevention. Upon application as anticoagulants in cancer patients, heparins were found to possess additional antitumor activities. Ectonucleotidases have recently been proposed as novel targets for cancer immunotherapy.

Methods and results

In the present study, we discovered that heparin and its derivatives act as potent, selective, allosteric inhibitors of the poorly investigated ectonucleotidase NPP1 (nucleotide pyrophosphatase/phosphodiesterase-1, CD203a). Structure-activity relationships indicated that NPP1 inhibition could be separated from the compounds' antithrombotic effect. Moreover, unfractionated heparin (UFH) and different low molecular weight heparins (LMWHs) inhibited extracellular adenosine production by the NPP1-expressing glioma cell line U87 at therapeutically relevant concentrations. As a consequence, heparins inhibited the ability of U87 cell supernatants to induce CD4+ T cell differentiation into immunosuppressive Treg cells.

Discussion

NPP1 inhibition likely contributes to the anti-cancer effects of heparins, and their specific optimization may lead to improved therapeutics for the immunotherapy of cancer.

Pharmacokinetic, Hemostatic, and Anticancer Properties of a Low-Anticoagulant Bovine Heparin

Heparin is a centennial anticoagulant drug broadly employed for treatment and prophylaxis of thromboembolic conditions. Although unfractionated heparin (UFH) has already been shown to have remarkable pharmacological potential for treating a variety of diseases unrelated with thromboembolism, including cancer, atherosclerosis, inflammation, and virus infections, its high anticoagulant potency makes the doses necessary to exert non-hemostatic effects unsafe due to an elevated bleeding risk. Our group recently developed a new low-anticoagulant bovine heparin (LABH) bearing the same disaccharide building blocks of the UFH gold standard sourced from porcine mucosa (HPI) but with anticoagulant potency approximately 85% lower (approximately 25 and 180 Heparin International Units [IU]/mg). In the present work, we investigated the pharmacokinetics profile, bleeding potential, and anticancer properties of LABH administered subcutaneous into mice. LABH showed pharmacokinetics profile similar to HPI but different from the low-molecular weight heparin (LMWH) enoxaparin and diminished bleeding potential, even at high doses. Subcutaneous treatment with LABH delays the early progression of Lewis lung carcinoma, improves survival, and brings beneficial health outcomes to the mice, without the advent of adverse effects (hemorrhage/mortality) seen in the animals treated with HPI. These results demonstrate that LABH is a promising candidate for prospecting new therapeutic uses for UFH.

Coagulation and inflammation in cancer: Limitations and prospects for treatment

The development of so-called immune checkpoint inhibitors (ICIs), which target specific molecular processes of tumour growth, has had a transformative effect on cancer treatment. Widespread use of antibody-based medicines to inhibit tumour cell immune evasion by modulating T cell responses is becoming more common. Despite this, response rates are still low, and secondary resistance is an issue that arises often. In addition, a wide range of serious adverse effects is triggered by enhancing the immunological response. As a result of an increased mortality rate, a higher prevalence of thrombotic complications is connected with an increased incidence of immunological reactions, complement activation, and skin toxicity. This suggests that the tumour microenvironment's interaction between coagulation and inflammation is important at every stage of the tumour's life cycle. The coagulation system's function in tumour formation is the topic of this review. By better understanding the molecular mechanisms in which tumour cells circulate, plasmatic coagulation and immune system cells are engaged, new therapy options for cancer sufferers may be discovered.

Pharmacokinetic, hemostatic and anticancer properties of a low-anticoagulant bovine heparin

Heparin is a centennial anticoagulant drug broadly employed for treatment and prophylaxis of thromboembolic conditions. Although unfractionated heparin (UFH) has already been shown to have remarkable pharmacological potential for treating a variety of diseases unrelated with thromboembolism, including cancer, atherosclerosis, inflammation, and virus infections, its high anticoagulant potency makes the doses necessary to exert non-hemostatic effects unsafe due to an elevated bleeding risk. Our group recently developed a new low-anticoagulant bovine heparin (LABH) bearing the same disaccharide building blocks of the UFH gold standard sourced from porcine mucosa (HPI) but with anticoagulant potency approximately 85% lower (approximately 25 and 180 Heparin International Units [IU]/mg). In the present work, we investigated the pharmacokinetics profile, bleeding potential, and anticancer properties of LABH administered subcutaneous into mice. LABH showed pharmacokinetics profile similar to HPI but different from the low-molecular weight heparin (LMWH) enoxaparin and diminished bleeding potential, even at high doses. Subcutaneous treatment with LABH delays the early progression of Lewis lung carcinoma, improves survival, and brings beneficial health outcomes to the mice, without the advent of adverse effects (hemorrhage/mortality) seen in the animals treated with HPI. These results demonstrate that LABH is a promising candidate for prospecting new therapeutic uses for UFH.

Involvement of platelet-derived VWF in metastatic growth of melanoma in the brain

Background

The prognosis of patients with brain metastases (BM) is poor despite advances in our understanding of the underlying pathophysiology. The high incidence of thrombotic complications defines tumor progression and the high mortality rate. We, therefore, postulated that von Willebrand factor (VWF) promotes BM via its ability to induce platelet aggregation and thrombosis.

Methods

We measured the abundance of VWF in the blood and intravascular platelet aggregates of patients with BM, and determined the specific contribution of endothelial and platelet-derived VWF using in vitro models and microfluidics. The relevance for the brain metastatic cascade in vivo was demonstrated in ret transgenic mice, which spontaneously develop BM, and by the intracardiac injection of melanoma cells.

Results

Higher levels of plasma VWF in patients with BM were associated with enhanced intraluminal VWF fiber formation and platelet aggregation in the metastatic tissue and peritumoral regions. Platelet activation triggered the formation of VWF multimers, promoting platelet aggregation and activation, in turn enhancing tumor invasiveness. The absence of VWF in platelets, or the blocking of platelet activation, abolished platelet aggregation, and reduced tumor cell transmigration. Anticoagulation and platelet inhibition consistently reduced the number of BM in preclinical animal models.

Conclusions

Our data indicate that platelet-derived VWF is involved in cerebral clot formation and in metastatic growth of melanoma in the brain. Targeting platelet activation with low-molecular-weight heparins represents a promising therapeutic approach to prevent melanoma BM.

Complexation of europium(III) with exopolysaccharides from a marine bacterium envisaged as luminescent probe in a theranostic approach

Exopolysaccharide (EPS) derivatives, produced by Alteromonas infernus bacterium, showed anti-metastatic properties in osteosarcoma (bone tumor). These EPSs could be employed as new drug delivery systems for therapeutic uses. They may represent a new class of ligands to be combined in a theranostic approach with fluorescent metals, such as Eu(III), to serve as imaging probe. The goal of this work was to investigate the feasibility of such coupling by time-resolved laser-induced fluorescence spectroscopy (TRLFS). Since these EPSs are polyelectrolytes their conformation could affect the complexation properties. Thus, viscosimetric measurements were performed as a function of their concentration as well as the background electrolyte concentration. Polysaccharides conformation exhibited a lower hydrodynamic volume for the highest ionic strengths. The resulting random-coiled conformation could affect the complexation with metal for high concentration but no change was evidenced when increasing europium concentration. Two sites of complexation of Eu(III) were evidenced by TRLFS in heparin, whereas only one site was evidenced in two modified EPSs produced from Alteromonas infernus.

Anticoagulation therapy promotes the tumor immune-microenvironment and potentiates the efficacy of immunotherapy by alleviating hypoxia

Purpose

Here, this study verifies that cancer-associated thrombosis (CAT) accelerates hypoxia, which is detrimental to the tumor immune microenvironment by limiting tumor perfusion. Therefore, we designed an oral anticoagulant therapy to improve the immunosuppressive tumor microenvironment and potentiate the efficacy of immunotherapy by alleviating tumor hypoxia.

Experimental design

A novel oral anticoagulant (STP3725) was developed to consistently prevent CAT formation. Tumor perfusion and hypoxia were analyzed with or without treating STP3725 in wild-type and P selectin knockout mice. Immunosuppressive cytokines and cells were analyzed to evaluate the alteration of the tumor microenvironment. Effector lymphocyte infiltration in tumor tissue was assessed by congenic CD45.1 mouse lymphocyte transfer model with or without anticoagulant therapy. Finally, various tumor models including K-Ras mutant spontaneous cancer model were employed to validate the role of the anticoagulation therapy in enhancing the efficacy of immunotherapy.

Results

CAT was demonstrated to be one of the perfusion barriers, which fosters immunosuppressive microenvironment by accelerating tumor hypoxia. Consistent treatment of oral anticoagulation therapy was proved to promote tumor immunity by alleviating hypoxia. Furthermore, this resulted in decrease of both hypoxia-related immunosuppressive cytokines and myeloid-derived suppressor cells while improving the spatial distribution of effector lymphocytes and their activity. The anticancer efficacy of αPD-1 antibody was potentiated by co-treatment with STP3725, also confirmed in various tumor models including the K-Ras mutant mouse model, which is highly thrombotic.

Conclusions

Collectively, these findings establish a rationale for a new and translational combination strategy of oral anticoagulation therapy with immunotherapy, especially for treating highly thrombotic cancers. The combination therapy of anticoagulants with immunotherapies can lead to substantial improvements of current approaches in the clinic.

Antiproliferative Properties of Scandium Exopolysaccharide Complexes on Several Cancer Cell Lines

Antimetastatic properties on both murine and human osteosarcoma cell lines (POS-1 and KHOS) have been evidenced using exopolysaccharide (EPS) derivatives, produced by Alteromonas infernus bacterium. These derivatives had no significant effect on the cell cycle neither a pro-apoptotic effect on osteosarcoma cells. Based on this observation, these EPSs could be employed as new drug delivery systems for therapeutic uses. A theranostic approach, i.e., combination of a predictive biomarker with a therapeutic agent, has been developed notably by combining with true pair of theranostic radionuclides, such as scandium ⁴⁷Sc/⁴⁴Sc. However, it is crucial to ensure that, once complexation is done, the biological properties of the vector remain intact, allowing the molecular tropism of the ligand to recognize its molecular target. It is important to assess if the biological properties of EPS evidenced on osteosarcoma cell lines remain when scandium is complexed to the polymers and can be extended to other cancer cell types. Scandium-EPS complexes were thus tested in vitro on human cell lines: MNNG/HOS osteosarcoma, A375 melanoma, A549 lung adenocarcinoma, U251 glioma, MDA231 breast cancer, and Caco2 colon cancer cells. An xCELLigence Real Cell Time Analysis (RTCA) technology assay was used to monitor for 160 h, the proliferation kinetics of the different cell lines. The tested complexes exhibited an anti-proliferative effect, this effect was more effective compared to EPS alone. This increase of the antiproliferative properties was explained by a change in conformation of EPS complexes due to their polyelectrolyte nature that was induced by complexation. Alterations of both growth factor-receptor signaling, and transmembrane protein interactions could be the principal cause of the antiproliferative effect. These results are very promising and reveal that EPS can be coupled to scandium for improving its biological effects and also suggesting that no major structural modification occurs on the ligand.

The Role of Platelet Cell Surface P-Selectin for the Direct Platelet-Tumor Cell Contact During Metastasis Formation in Human Tumors

Mammalian platelets, devoid of nuclei, are the smallest cells in the blood stream. They are essential for hemostasis, but also transmit cell signals that are necessary for regenerative and generative processes such as inflammation, immunity and tissue repair. In particular, in malignancies they are also associated with cell proliferation, angiogenesis, and epithelial-mesenchymal transition. Platelets promote metastasis and resistance to anti-tumor treatment. However, fundamental principles of the interaction between them and target cells within tumors are complex and still quite obscure. When injected into animals or circulating in the blood of cancer patients, cancer cells ligate platelets in a timely manner closely related to platelet activation either by direct contact or by cell-derived substances or microvesicles. In this context, a large number of different surface molecules and transduction mechanisms have been identified, although the results are sometimes species-specific and not always valid to humans. In this mini-review, we briefly summarize the current knowledge on the role of the direct and indirect platelet-tumor interaction for single steps of the metastatic cascade and specifically focus on the functional role of P-selectin.

Advances in the Management of Cancer-Associated Thrombosis

The association between cancer and venous thromboembolism (VTE) has been established for more than 150 years. Nevertheless, cancer-associated thrombosis still remains a major clinical challenge and is associated with significant morbidity and mortality for patients with cancer. The clinical presentation of cancer-associated thrombosis can be distinct from that of a patient without an underlying malignancy. Moreover, specific cancer types, including pancreatic cancer and hematological malignancies, as well as advanced stage disease can confer a significant thrombotic risk. This risk is further augmented by specific anticancer treatment modalities. The pathophysiology of cancer-associated thrombosis is complex and multifactorial. However, understanding the biological mechanisms underpinning VTE risk may provide insight into novel targeted prophylaxis in cancer patients. Over the last decade, low-molecular-weight heparin has been the preferred anticoagulant agent for patients with cancer-associated thrombosis due to improved efficacy compared with vitamin K antagonists. However, the advent of direct oral anticoagulants (DOACs) has added to the repertoire of ammunition now at the disposal of clinicians to aid in the management of cancer-associated thrombosis. Several randomized controlled trials have now been published, demonstrating DOAC as a noninferior alternative for both the treatment and prevention of cancer-associated thrombosis. Notwithstanding this, limitations for their widespread use remain, with the potential for increased bleeding risk, drug interactions, and poor DOAC metabolism. This review discusses the evidence base for the incidence and risk factors associated with VTE in cancer, development, and refinement of risk prediction models and novel advances in the therapeutic management of cancer-associated thrombosis.

Antidepressants Promote and Prevent Cancers

The review states that antidepressants (ADs) increase brain-derived neurotrophic factor (BDNF) transmission concomitantly in the brain and the blood: ADs increasing BDNF synthesis in specific areas of the central nervous system (CNS) could presumably affect megakaryocyte's production of platelets. ADs increase BDNF levels in the CNS and improve mood. In the blood, ADs increase BDNF release from platelets. The hypothesis presented here is that the release of BDNF from platelets contributes to the ADs effects on neurogenesis and on tumor growth in the cancer disease. Oncological studies indicate that chemicals ADs exert an aggravating effect on the cancer disease, possibly by promoting proplatelets formation and enhancing BDNF release from platelets in the tumor.

The Anticoagulant and Nonanticoagulant Properties of Heparin

Heparins represent one of the most frequently used pharmacotherapeutics. Discovered around 1926, routine clinical anticoagulant use of heparin was initiated only after the publication of several seminal papers in the early 1970s by the group of Kakkar. It was shown that heparin prevents venous thromboembolism and mortality from pulmonary embolism in patients after surgery. With the subsequent development of low-molecular-weight heparins and synthetic heparin derivatives, a family of related drugs was created that continues to prove its clinical value in thromboprophylaxis and in prevention of clotting in extracorporeal devices. Fundamental and applied research has revealed a complex pharmacodynamic profile of heparins that goes beyond its anticoagulant use. Recognition of the complex multifaceted beneficial effects of heparin underscores its therapeutic potential in various clinical situations. In this review we focus on the anticoagulant and nonanticoagulant activities of heparin and, where possible, discuss the underlying molecular mechanisms that explain the diversity of heparin's biological actions.

The Antitumor Effect of Heparin is not Mediated by Direct NK Cell Activation

Natural killer (NK) cells are innate lymphocytes responsible for the elimination of infected or transformed cells. The activation or inhibition of NK cells is determined by the balance of target cell ligand recognition by stimulatory and inhibitory receptors on their surface. Previous reports have suggested that the glycosaminoglycan heparin is a ligand for the natural cytotoxicity receptors NKp30, NKp44 (human), and NKp46 (both human and mouse). However, the effects of heparin on NK cell homeostasis and function remain unclear. Here, we show that heparin does not enhance NK cell proliferation or killing through NK cell activation. Alternatively, in mice models, heparin promoted NK cell survival in vitro and controlled B16-F10 melanoma metastasis development in vivo. In human NK cells, heparin promisingly increased interferon (IFN)-γ production in synergy with IL-12, although the mechanism remains elusive. Our data showed that heparin is not able to increase NK cell cytotoxicity.

Co-delivery of doxorubicin and epacadostat via heparin coated pH-sensitive liposomes to suppress the lung metastasis of melanoma

High metastasis is responsible for the failure in the treatment of melanoma. Chemoimmunotherapy has shown conspicuous inhibition effects not only on the growth of tumor in situ, but also on the metastasis to distant organs. Given that the indoleamine-2,3 dioxygenase (IDO) overexpressed in the microenvironment of tumor leads to the immune escape, the combination of chemotherapeutic drug and IDO inhibitor might be a promising chemoimmunotherapy. Besides, the hematogenous metastasis mediated by platelets was supposed to be blocked by the heparin (HP). Therefore, a drug delivery system with all these elements involved might be a potential treatment for melanoma. Here, we developed a pH-sensitive liposomal dual-delivery system for doxorubicin (DOX) and epacadostat (EPA) with HP coated (HP/LDE). It was confirmed to enhance cytotoxicity and apoptosis, reverse the platelets-activated epithelial mesenchymal transformation (EMT) and prevent the invasion and migration in vitro. After systemic administration, HP/LDE provided the optimum anti-metastasis effect on the melanoma. The results of evaluation on DC maturation, CD8+ cytotoxic T lymphocytes (CTLs) activation and T cell mediated cytotoxicity were consistent in vitro and in vivo. Taken together, our study established a functional liposomal dual-delivery system with ideal anti-metastasis efficacy on melanoma.

Non-Anticoagulant Heparan Sulfate from the Ascidian Phallusia nigra Prevents Colon Carcinoma Metastasis in Mice by Disrupting Platelet-Tumor Cell Interaction

Although metastasis is the primary cause of death in patients with malignant solid tumors, efficient anti-metastatic therapies are not clinically available currently. Sulfated glycosaminoglycans from marine sources have shown promising pharmacological effects, acting on different steps of the metastatic process. Oversulfated dermatan sulfates from ascidians are effective in preventing metastasis by inhibition of P-selectin, a platelet surface protein involved in the platelet-tumor cell emboli formation. We report in this work that the heparan sulfate isolated from the viscera of the ascidian Phallusia nigra drastically attenuates metastases of colon carcinoma cells in mice. Our in vitro and in vivo assessments demonstrate that the P. nigra glycan has very low anticoagulant and antithrombotic activities and a reduced hypotension potential, although it efficiently prevented metastasis. Therefore, it may be a promising candidate for the development of a novel anti-metastatic drug.

Quantification of heparin's antimetastatic effect by single-cell force spectroscopy

In circulation, cancer cells induce platelet activation, leading to the formation of a cancer cell-encircling platelet cloak which facilitates each step of the metastatic cascade. Since cancer patients treated with the anticoagulant heparin showed reduced metastasis rates and improved survival, it is supposed that heparin suppresses the cloak's formation by inhibiting the interaction between platelet's adhesion molecule P-selectin with its ligands on cancer cells. To quantify this heparin effect, we developed a single-cell force spectroscopy approach and quantified the adhesion (maximum adhesion force [F_A ] and detachment work [W_D ]) between platelets and human non-small cell lung cancer cells (A549). A configuration was used in which A549 cells were glued to tipless cantilevers and force-distance (F-D) curves were recorded on a layer of activated platelets. The concentration-response relationship was determined for heparin at concentrations between 1 and 100 U/mL. Sigmoid dose-response fit revealed half-maximal inhibitory concentration (IC₅₀ ) values of 8.01 U/mL (F_A ) and 6.46 U/mL (W_D ) and a maximum decrease of the adhesion by 37.5% (F_A ) and 38.42% (W_D ). The effect of heparin on P-selectin was tested using anti-P-selectin antibodies alone and in combination with heparin. Adding heparin after antibody treatment resulted in an additional reduction of 9.52% (F_A ) and 7.12% (W_D ). Together, we quantified heparin's antimetastatic effect and proved that it predominantly is related to the blockage of P-selectin. Our approach represents a valuable method to investigate the adhesion of platelets to cancer cells and the efficiency of substances to block this interaction.

A systematic review on the effects of direct oral anticoagulants on cancer growth and metastasis in animal models

BACKGROUND

Direct oral anticoagulants (DOACs) are now the first choice thromboprophylaxis in cancer patients who do not have a high risk of bleeding. In addition to the anticoagulant effects, potential anti-tumor effects of DOACs have also been studied in animal cancer models. In this study, we summarize the effects of DOACs on cancer growth and metastasis in animal models through a systematic review with a qualitative analysis.

METHODS

PubMed, EMBASE and Web of Science were systematically searched for original studies that describe animal models of cancer in which one of the experimental groups received DOAC monotherapy, and which reported quantitatively on primary tumor or metastases.

RESULTS

Nine studies - reporting a total of 19 animal experiments - met the inclusion criteria. These 19 experiments included spontaneous cancer (n = 2), carcinogenicity (n = 2), xenograft (n = 7) and syngeneic (n = 8) models, encompassing orthotopic (n = 7), subcutaneous (n = 5), intraperitoneal (n = 1) and intravenous (n = 2) injection of cancer cells and included treatments with the DOACs ximelagatran (n = 4), dabigatran etexilate (n = 6) and/or rivaroxaban (n = 11). DOAC treatment decreased tumor growth at implanted and metastatic site in 18.8% (3/16) and 20.0% (3/15) of the experiments, respectively. Conversely, DOACs increased tumor growth at implanted and metastatic site in 6.3% (1/16) and 20.0% (3/15) of the experiments, respectively.

CONCLUSION

DOAC monotherapy resulted in neoplastic changes in a rat carcinogenicity study, showed a lack of effect in mouse xenograft models, while the effect on cancer growth and metastasis in mouse syngeneic models depended on the timing of DOAC treatment and type of cancer model used.

A concomitant bone fracture delays cognitive recovery from traumatic brain injury

BACKGROUND

Brain injury progression after severe traumatic brain injury (TBI) is associated with worsening cerebral inflammation but it is unknown how a concomitant bone fracture (BF) affects this progression. Enoxaparin (ENX) decreases penumbral leukocyte mobilization after TBI and improves neurologic recovery. We hypothesized that a concomitant BF worsens learning/memory recovery weeks after TBI and that ENX improves this recovery.

METHODS

CD1 male mice underwent controlled cortical impact or sham craniotomy with or without tibial fracture, receiving either daily ENX (0.8 mg/kg) or saline for 14 days after injury. Randomization defined four groups (Sham, TBI only, TBI + Fx, TBI + Fx + ENX, n = 5/each). Body weight loss and neurologic recovery (Garcia Neurologic Test, max score = 18) were assessed each day. Mouse learning (swimming time [s] and total distance [m] to reach the submerged platform Days 14 to 17 after TBI) and memory (swimming time [s] in platform quadrant after platform removed [probe]) was assessed by the Morris water maze. Ly-6G (cerebral neutrophil sequestration) and glial fibrillary acidic protein were evaluated by immunohistochemistry in brain tissue post mortem. Analysis of variance with Tukey's post hoc test determined significance (p < 0.05).

RESULTS

A concurrent BF worsened Garcia Neurologic Test scores post-TBI Days 2 to 4 (p < 0.01) as compared with TBI only, and ENX reversed this worsening on Day 4 (p < 0.01). Learning was significantly slower (greater swimming time and distance) in TBI + Fx versus TBI only on Day 17 (p < 0.01). This was despite similar swimming velocities in both groups, indicating intact extremity motor function. Memory was similar in isolated TBI and Sham which was significantly better than in TBI + Fx animals (p < 0.05). Glial fibrillary acidic protein-positive cells in penumbral cortex were most prevalent in TBI + Fx animals, significantly greater than in Sham (p < 0.05).

CONCLUSION

A long BF accompanying TBI worsens early neurologic recovery and subsequent learning/memory. Enoxaparin may partially counter this and improve neurologic recovery.

Direct Oral Anticoagulant Drugs: On the Treatment of Cancer-Related Venous Thromboembolism and their Potential Anti-Neoplastic Effect

Cancer patients develop a hypercoagulable state with a four- to seven-fold higher thromboembolic risk compared to non-cancer patients. Thromboembolic events can precede the diagnosis of cancer, but they more often occur at diagnosis or during treatment. After malignancy itself, they represent the second cause of death. Low molecular weight heparins are the backbone of the treatment of cancer-associated thromboembolism. This treatment paradigm is possibly changing, as direct oral anticoagulants (DOACs) may prove to be an alternative therapeutic option. The currently available DOACs were approved during the first and second decades of the 21st century for various clinical indications. Three molecules (apixaban, edoxaban and rivaroxaban) are targeting the activated factor X and one (dabigatran) is directed against the activated factor II, thrombin. The major trials analyzed the effect of these agents in the general population, with only a small proportion of cancer patients. Two published and several ongoing studies are specifically investigating the use of DOACs in cancer-associated thromboembolism. This article will review the current available literature on the use of DOACs in cancer patients. Furthermore, we will discuss published data suggesting potential anti-cancer actions exerted by non-anticoagulant effects of DOACs. As soon as more prospective data becomes available, DOACs are likely to be considered as a potential new therapeutic option in the armamentarium for patients suffering of cancer-associated thromboembolism.

Heparan Sulfate Mimetics in Cancer Therapy: The Challenge to Define Structural Determinants and the Relevance of Targets for Optimal Activity

Beyond anticoagulation, the therapeutic potential of heparin derivatives and heparan sulfate (HS) mimetics (functionally defined HS mimetics) in oncology is related to their ability to bind and modulate the function of a vast array of HS-binding proteins with pivotal roles in cancer growth and progression. The definition of structural/functional determinants and the introduction of chemical modifications enabled heparin derivatives to be identified with greatly reduced or absent anticoagulant activity, but conserved/enhanced anticancer activity. These studies paved the way for the disclosure of structural requirements for the inhibitory effects of HS mimetics on heparanase, selectins, and growth factor receptor signaling, as well as for the limitation of side effects. Actually, HS mimetics affect the tumor biological behavior via a multi-target mechanism of action based on their effects on tumor cells and various components of the tumor microenvironment. Emerging evidence indicates that immunomodulation can participate in the antitumor activity of these agents. Significant ability to enhance the antitumor effects of combination treatments with standard therapies was shown in several tumor models. While the first HS mimetics are undergoing early clinical evaluation, an improved understanding of the molecular contexts favoring the antitumor action in certain malignancies or subgroups is needed to fully exploit their potential.

Association of pretreatment thrombocytosis with prognosis in ovarian cancer: a systematic review and meta-analysis

Objective

To investigate the association between pre-treatment thrombocytosis and prognosis in patients with ovarian cancer (OC).

Methods

PubMed, EMBASE, and the Cochrane Library were searched for articles regarding the prognosis of OC patients with pre-treatment thrombocytosis by the end of March 2018. Pooled estimates for overall survival (OS) and progression-free survival (PFS) events were calculated as hazard ratios (HRs) either on a fixed or random effect model by Stata 13.0 software. Funnel plot and Egger's test were applied to evaluate publication bias and sensitivity analyses were undertaken to estimate the strength of outcomes.

Results

Eleven studies that met the inclusion criteria were enrolled, including a total of 4,953 patients. Pooled results showed that pre-treatment thrombocytosis was significantly associated with OS (HR=1.722; 95% confidence interval [CI]=1.437–2.064) and PFS (HR=1.452; 95% CI=1.323–1.593) in the cohort. Significant correlation was found in OS and PFS between pre-treatment thrombocytosis and both epithelial OC (all stages and differentiation degrees of OC) and advanced epithelial OC (III or IV) by subgroup analyses, which were performed according to publication year, country, case numbers, OC category, International Federation of Gynecology and Obstetrics stage, and cut-off value. However, subgroup analyses indicated no significant correlation between pre-treatment thrombocytosis and OS for patients with high-grade serous (poorly differentiated or undifferentiated) OC (HR=1.220; 95% CI=0.946–1.573; p=0.125). Egger's test demonstrated no obvious publication bias in the articles enrolled in this study (OS: p=0.226; PFS: p=0.071).

Conclusion

Pre-treatment thrombocytosis might be taken as an independent prognostic indicator for patients with OC.

Cerebral Edema and Neurological Recovery after Traumatic Brain Injury Are Worsened if Accompanied by a Concomitant Long Bone Fracture

Progression of severe traumatic brain injury (TBI) is associated with worsening cerebral inflammation, but it is unknown how a concomitant bone fracture (FX) affects this progression. Enoxaparin (ENX), a low molecular weight heparin often used for venous thromboembolic prophylaxis, decreases penumbral leukocyte (LEU) mobilization in isolated TBI and improves neurological recovery. We investigated if TBI accompanied by an FX worsens LEU-mediated cerebral inflammation and if ENX alters this process. CD1 male mice underwent controlled cortical impact (CCI) or sham craniotomy with or without an open tibial FX, and received either ENX (1 mg/kg, three times/day) or saline for 2 days following injury. Randomization defined four groups (Sham, CCI, CCI+FX, CCI+FX+ENX, n = 10/group). Two days after CCI, neurological recovery was assessed with the Garcia Neurological Test (GNT); intravital microscopy (LEU rolling and adhesion, microvascular leakage) and blood hemoglobin levels were also evaluated. Penumbral cerebral neutrophil sequestration (Ly-6G immunohistochemistry [IHC]) were evaluated post-mortem. In vivo LEU rolling was greater in CCI+FX (45.2 ± 4.8 LEUs/100 μm/min) than in CCI alone (26.5 ± 3.1, p = 0.007), and was suppressed by ENX (23.2 ± 5.5, p = 0.003 vs. CCI + FX). Neurovascular permeability was higher in CCI+FX (71.1 ± 2.9%) than CCI alone (42.5 ± 2.3, p < 0.001). GNT scores were lower in CCI+FX (15.2 ± 0.2) than in CCI alone (16.3 ± 0.3, p < 0.001). Hemoglobin was lowest in the CCI+FX+ENX group, lower than in Sham or CCI. IHC demonstrated greatest polymorphonuclear neutrophil (PMN) invasion in CCI+FX in uninjured cerebral territories. A concomitant long bone FX worsens TBI-induced cerebral LEU mobilization, microvascular leakage, and cerebral edema, and impairs neurological recovery at 48 h. ENX suppresses this progression but may increase bleeding.

Pleiotropic effects of heparins: does anticoagulant treatment increase survival in cancer patients?

The association between venous thromboembolism (VTE) and cancer has been recognized for more than 100 years. Numerous studies have been performed to investigate strategies to decrease VTE incidence and to establish whether treating VTE impacts cancer progression and overall survival. Accordingly, it is important to understand the role of the hemostatic system in tumorigenesis and progression, as there is abundant evidence associating it with cell survival and proliferation, tumor angiogenesis, invasion, and dissemination, and metastasis formation. In attempts to further the scientific evidence, several studies examine survival benefits in cancer patients treated with anticoagulant therapy, specifically treatment with vitamin K antagonists, unfractionated heparin, and low-molecular-weight heparin. Several studies and meta-analyses have been conducted with a special focus on brain tumors. However, no definitive conclusions have been obtained, and more well-designed clinical trials are needed.

Heparins that block VEGF-A-mediated von Willebrand factor fiber generation are potent inhibitors of hematogenous but not lymphatic metastasis

Von Willebrand factor (VWF) serves as a nidus for platelet aggregation and thrombosis. We hypothesize that VWF fibers contribute to the development of venous thromboembolism (VTE) and to metastasis formation. Here, we show that vascular and lymphatic endothelial cells (ECs) express VWF in vitro and release VWF fibers after activation by tumor cell supernatants. In contrast, an ex vivo analysis of primary mouse tumors revealed the presence of VWF fibers in the blood microvasculature but not in lymphatic vessels. Unlike the anticoagulant Fondaparinux, an inhibitor of thrombin generation, the low-molecular-weight heparin (LMWH) Tinzaparin inhibited VWF fiber formation and vessel occlusion in tumor vessels by blocking thrombin-induced EC activation and vascular endothelial growth factor-A (VEGF-A)-mediated VWF release. Intradermal tumor cell inoculation in VWF- and ADAMTS13-deficient mice did not alter lymph node metastases compared with wild type animals. Interestingly, multiple tumor-free distal organs exhibited hallmarks of malignancy-related VTE, including luminal VWF fibers, platelet-rich thrombi and vessel occlusions. Furthermore, ADAMTS13 deficiency, characterized by prolonged intraluminal VWF network lifetimes, resulted in a severely increased number of metastatic foci in an experimental model of hematogenous lung seeding. Treatment with Tinzaparin inhibited tumor-induced release of VWF multimers, impeded platelet aggregation and decreased lung metastasis. Thus, our data strongly suggest a critical role of luminal VWF fibers in determining the occurrence of thrombosis and cancer metastasis. Moreover, the findings highlight LMWHs as therapeutic strategy to treat thrombotic complications while executing anti-metastatic activities.

Development of low molecular weight heparin based nanoparticles for metastatic breast cancer therapy

Tumor metastasis is the primary obstacle in cancer treatment and is always the leading cause of human death. And heparin and its derivatives are potential anti-metastatic agents with good biocompatibility. In this work, low molecular weight heparin (LMWH) based LMWH-Cholesterol (LHC) conjugates were prepared for intravenous delivery of doxorubicin (DOX). The DOX/LHC nanoparticles (DOX/LHC NPs) exhibited a spherical shape with a mean diameter of 135.5±2.2nm and had a longer circulation time than that of DOX. The in vitro results confirmed that the DOX/LHC NPs was more effectively taken up by 4T1 cells and showed a stronger anti-metastatic effect by cell invasion and cell migration compared with DOX. Meanwhile, DOX/LHC NPs also exhibited superior anti-metastatic effects in the pulmonary metastasis model compared with other groups. The reason may be account for the synergistic effect between the cytotoxic drug of DOX and its drug carrier of LMWH based nanoparticles, which is capable of anti-metastatic and anti-angiogenic efficiency. Thus DOX/LHC nanoparticles could be a promising anti-metastatic drug delivery system for postoperative chemotherapy.

The mechanisms how heparin affects the tumor cell induced VEGF and chemokine release from platelets to attenuate the early metastatic niche formation

Metastasis is responsible for the majority of cancer associated fatalities. Tumor cells leaving the primary tumor and entering the blood flow immediately interact with platelets. Activated platelets contribute in different ways to cancer cell survival and proliferation, e.g. in formation of the early metastatic niche by release of different growth factors and chemokines. Here we show that a direct interaction between platelets and MV3 melanoma or MCF7 breast cancer cells induces platelet activation and a VEGF release in citrated plasma that cannot be further elevated by the coagulation cascade and generated thrombin. In contrast, the release of platelet-derived chemokines CXCL5 and CXCL7 depends on both, a thrombin-mediated platelet activation and a direct interaction between tumor cells and platelets. Preincubation of platelets with therapeutic concentrations of unfractionated heparin reduces the tumor cell initiated VEGF release from platelets. In contrast, tumor cell induced CXCL5 and CXCL7 release from platelets was not impacted by heparin pretreatment in citrated plasma. In defibrinated, recalcified plasma, on the contrary, heparin is able to reduce CXCL5 and CXCL7 release from platelets by thrombin inhibition. Our data indicate that different chemokines and growth factors in diverse platelet granules are released in tightly regulated processes by various trigger mechanisms. We show for the first time that heparin is able to reduce the mediator release induced by different tumor cells both in a contact and coagulation dependent manner.

In vitro effects of Apixaban on 5 different cancer cell lines

BACKGROUND

Cancer is associated with hypercoagulability. However, several data suggest that anticoagulant drugs may have an effect on tumor development and progression mediated by both coagulation dependent processes and non-coagulation dependent processes. Therefore, we investigated the in vitro effects of Apixaban on cell proliferation, mortality, cell migration, gene expression and matrix metalloproteinase in 5 different cancer cell lines.

METHODS

The following cancer cell lines, and 2 normal fibroblast cultures (lung and dermal fibroblasts), were studied: OVCAR3 (ovarian cancer), MDA MB 231 (breast cancer), CaCO-2 (colon cancer), LNCaP (prostate cancer) and U937 (histiocytic lymphoma). Proliferation and cell mortality were assessed in control cells and Apixaban treated cultures (dose from 0.1 to 5 μg/ml, 0 to 96-h). Necrosis/Apoptosis (fluorescence microscopy), cell migration (24-h after scratch test), matrix metalloproteinase (MMP) activity and mRNA expression (RT PCR) of p16, p21, p53 and HAS were also assessed.

RESULTS

High-dose (5 μg/ml) Apixaban incubation was associated with a significantly reduced proliferation in 3 cancer cell lines (OVCAR3, CaCO-2 and LNCaP) and with increased cancer cell mortality in all, except LNCaP, cancer lines. Apoptosis seems to account for the increased mortality. The migration capacity seems to be impaired after high-dose Apixaban incubation in OVCAR3 and CaCO-2 cells. Data on mRNA expression suggest a consistent increase in tumor suppression gene p16 in all cell lines.

CONCLUSIONS

Our data suggest that high-dose Apixaban may be able to interfere with cancer cell in vitro, reducing proliferation and increasing cancer cell mortality through apoptosis in several cancer cell lines.

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.

Initial anticoagulation in patients with pulmonary embolism: thrombolysis, unfractionated heparin, LMWH, fondaparinux, or DOACs?

The initial treatment of haemodynamically stable patients with pulmonary embolism (PE) has dramatically changed since the introduction of low molecular weight heparins (LMWHs). With the recent discovery of the direct oral anticoagulant drugs (DOACs), initial treatment of PE will be simplified even further. In several large clinical trials it has been demonstrated that DOACs are not inferior to standard therapy for the initial treatment of PE, and because of their practicability they are becoming the agents of first choice. However, many relative contraindications to DOACs were exclusion criteria in the clinical trials. Therefore, LMWHs will continue to play an important role in initial PE treatment and in some cases there still is a role for unfractionated heparin (UFH). In this review we will give an overview of the biophysical, pharmacokinetic and pharmacodynamic properties of anticoagulants currently available for the initial management of PE. In addition, we will provide a comprehensive overview of the indications for the use of UFH, LMWHs and DOACs in the initial management of PE from a pharmacokinetic/-dynamic point of view.

Old and new applications of non-anticoagulant heparin

The aim of this chapter is to provide an overview of non-anticoagulant effects of heparins and their potential use in new therapeutic applications. Heparin and heparin derivatives have been tested in inflammatory, pulmonary and reproductive diseases, in cardiovascular, nephro- and neuro-tissue protection and repair, but also as agents against angiogenesis, atheroschlerosis, metastasis, protozoa and viruses. Targeting and inhibition of specific mediators involved in the inflammatory process, promoting some of the above mentioned pathologies, are reported along with recent studies of heparin conjugates and oral delivery systems. Some reports from the institute of the authors, such as those devoted to glycol-split heparins are also included. Among the members and derivatives of this class, several are undergoing clinical trials as antimetastatic and antimalarial agents and for the treatment of labour pain and severe hereditary anaemia. Other heparins, whose therapeutic targets are non-anticoagulant such as nephropathies, retinopathies and cystic fibrosis are also under investigation.

Emodin-Loaded PLGA-TPGS Nanoparticles Combined with Heparin Sodium-Loaded PLGA-TPGS Nanoparticles to Enhance Chemotherapeutic Efficacy Against Liver Cancer

PURPOSE

Heparin sodium (HS)-loaded polylactic-co-glycolic acid-D-α-tocopheryl polyethylene glycol 1000 succinate (PLGA-TPGS) nanoparticles (HPTNs) were prepared as a sustained and targeting delivery carrier and combined with emodin (EMO)-loaded PLGA-TPGS nanoparticles (EPTNs), which were investigated previously to form a combination therapy system for the treatment of liver cancer.

METHODS

To assess cellular uptake and evaluate the liver-targeting capacity by analyzing the drug concentrations and frozen slices, HS/eosin-loaded PLGA-TPGS nanoparticles, HS/fluorescein- loaded PLGA-TPGS nanoparticles and EMO/C6-loaded PLGA-TPGS nanoparticles, which contained eosin, fluorescein and C6 as fluorescent probes, respectively, were also prepared. All of these nanoparticles were characterized in terms of their size, size distribution, surface charge, drug loading, encapsulation efficiency, in vitro release profile and cellular uptake. The apoptosis of HepG2 cells induced by EPTNs in combination with HPTNs was determined by Annexin V-FITC staining and PI labelling.

RESULTS

Transmission electron microscopy indicated that these nanoparticles were stably dispersed spheres with sizes ranging from 100 to 200 nm. The results demonstrated that fluorescent nanoparticles were internalized into HepG2 and HCa-F cells efficiently and had improved liver-targeting properties. The combination of EPTNs and HPTNs effectively inhibited cell growth in vitro and had a remarkable synergistic anticancer effect in vivo. EPTNs combined with HPTNs induced HepG2 cell apoptosis with synergistic effects. The liver H&E slice images of a hepatocarcinogenic mouse model indicated that EPTNs in combination with HPTNs significantly suppressed tumour growth in vivo.

CONCLUSIONS

The research suggests that the combination therapy system of EPTNs and HPTNs could be a new direction for liver cancer therapy.

Targeting Selectins and Their Ligands in Cancer

Aberrant glycosylation is a hallmark of cancer cells with increased evidence pointing to a role in tumor progression. In particular, aberrant sialylation of glycoproteins and glycolipids has been linked to increased immune cell evasion, drug evasion, drug resistance, tumor invasiveness, and vascular dissemination, leading to metastases. Hypersialylation of cancer cells is largely the result of overexpression of sialyltransferases (STs). Differentially, humans express twenty different STs in a tissue-specific manner, each of which catalyzes the attachment of sialic acids via different glycosidic linkages (α2-3, α2-6, or α2-8) to the underlying glycan chain. One important mechanism whereby overexpression of STs contributes to an enhanced metastatic phenotype is via the generation of selectin ligands. Selectin ligand function requires the expression of sialyl-Lewis X and its structural isomer sialyl-Lewis A, which are synthesized by the combined action of alpha α1-3-fucosyltransferases, α2-3-sialyltransferases, β1-4-galactosyltranferases, and N-acetyl-β-glucosaminyltransferases. The α2-3-sialyltransferases ST3Gal4 and ST3Gal6 are critical to the generation of functional E- and P-selectin ligands and overexpression of these STs have been linked to increased risk of metastatic disease in solid tumors and poor outcome in multiple myeloma. Thus, targeting selectins and their ligands as well as the enzymes involved in their generation, in particular STs, could be beneficial to many cancer patients. Potential strategies include ST inhibition and the use of selectin antagonists, such as glycomimetic drugs and antibodies. Here, we review ongoing efforts to optimize the potency and selectivity of ST inhibitors, including the potential for targeted delivery approaches, as well as evaluate the potential utility of selectin inhibitors, which are now in early clinical development.

Biochemical and toxicological evaluation of nano-heparins in cell functional properties, proteasome activation and expression of key matrix molecules

The glycosaminoglycan heparin and its derivatives act strongly on blood coagulation, controlling the activity of serine protease inhibitors in plasma. Nonetheless, there is accumulating evidence highlighting different anticancer activities of these molecules in numerous types of cancer. Nano-heparins may have great biological significance since they can inhibit cell proliferation and invasion as well as inhibiting proteasome activation. Moreover, they can cause alterations in the expression of major modulators of the tumor microenvironment, regulating cancer cell behavior. In the present study, we evaluated the effects of two nano-heparin formulations: one isolated from porcine intestine and the other from the sea squirt Styela plicata, on a breast cancer cell model. We determined whether these nano-heparins are able to affect cell proliferation, apoptosis and invasion, as well as proteasome activity and the expression of extracellular matrix molecules. Specifically, we observed that nano-Styela compared to nano-Mammalian analogue has higher inhibitory role on cell proliferation, invasion and proteasome activity. Moreover, nano-Styela regulates cell apoptosis, expression of inflammatory molecules, such as IL-6 and IL-8 and reduces the expression levels of extracellular matrix macromolecules, such as the proteolytic enzymes MT1-MMP, uPA and the cell surface proteoglycans syndecan-1 and -2, but not on syndecan-4. The observations reported in the present article indicate that nano-heparins and especially ascidian heparin are effective agents for heparin-induced effects in critical cancer cell functions, providing an important possibility in pharmacological targeting.

Pharmacology of Heparin and Related Drugs

Heparin has been recognized as a valuable anticoagulant and antithrombotic for several decades and is still widely used in clinical practice for a variety of indications. The anticoagulant activity of heparin is mainly attributable to the action of a specific pentasaccharide sequence that acts in concert with antithrombin, a plasma coagulation factor inhibitor. This observation has led to the development of synthetic heparin mimetics for clinical use. However, it is increasingly recognized that heparin has many other pharmacological properties, including but not limited to antiviral, anti-inflammatory, and antimetastatic actions. Many of these activities are independent of its anticoagulant activity, although the mechanisms of these other activities are currently less well defined. Nonetheless, heparin is being exploited for clinical uses beyond anticoagulation and developed for a wide range of clinical disorders. This article provides a "state of the art" review of our current understanding of the pharmacology of heparin and related drugs and an overview of the status of development of such drugs.

Reduction-responsive modification-induced higher efficiency for attenuation of tumor metastasis of low molecular weight heparin functionalized liposomes

Higher efficiency of attenuation of tumor metastasis was achievedviareduction-responsive modification of low molecular weight heparin on doxorubicin liposomes.

ALK1 expression in oral lichen planus: a possible relation to microvessel density

OBJECTIVE

To assess the expression of activin receptor-like kinase 1 (ALK1) and investigate its possible relationship with microvessel density (MVD) in different forms of oral lichen planus (OLP) compared to controls' biopsies.

METHODS

Biopsies from 20 reticular/papular OLP (R/PLP), 20 atrophic/erosive OLP (A/ELP) patients, and 20 healthy subjects were immunohistochemically analyzed and statistically compared and correlated for ALK1 expression and MVD as assessed by CD34 expression.

RESULTS

All OLP specimens revealed the presence of positive cytoplasmic CD34 immunostaining in endothelial cells, with statistically high significant MVD in each of R/PLP (Median; M = 4.40) and A/ELP (M = 7.69) compared to controls (M = 1.16) (P < 0.001). Statistically significant MVD was found in A/ELP compared to R/PLP (P < 0.001). All control specimens revealed negative ALK1 immunostaining of the few inflammatory cells found, while 85% of A/ELP cases and 70% of R/PLP cases showed positively immunostained sections for ALK-1, with statistically significant higher ALK1 expression In A/ELP (M = 1.95) compared to R/PLP (M = 0.86) (P = 0.005). No significant correlation between CD34 and ALK1 was detected in R/PLP (r = 0.081), while a barely moderate positive correlation was found in A/ELP (r = 0.396).

CONCLUSIONS

ALK1 expression and MVD are increased in OLP, particularly in A/ELP type.

Circulating Tumor Cell Analyses in Patients With Esophageal Squamous Cell Carcinoma Using Epithelial Marker-Dependent and -Independent Approaches

In several epithelial malignancies, detection of circulating tumor cells (CTCs) in the peripheral blood has diagnostic, prognostic, and therapeutic implications. However, the clinical relevance of CTCs in esophageal squamous cell carcinoma (ESCC) has not yet been ascertained. The study was conducted with the aim of determining the clinical significance of CTCs in patients with ESCC by using 2 CTC detection systems, one epithelial marker-dependent and the other epithelial marker-independent. Paired peripheral blood samples were prospectively obtained from 61 ESCC patients before treatment and were analyzed for CTCs isolated by the CellSearch system (CS) and the method of isolation by size of epithelial tumor (ISET). Blood samples from 22 healthy volunteers were used as controls. Out of 61 study subjects, CTCs were detected in 20 patients (32.8%) by the ISET method and in only 1 patient (1.6%) by the CS method. Circulating tumor microemboli (CTM) were observed in 3 of 61 (4.9%) patients using ISET, but were undetectable in any of the patient by CS method. No CTCs/CTM were detected by either method in control groups. By ISET method, the presence of CTCs appeared to correlate with the stage of ESCC and with the baseline median platelet levels. No correlation with any other relevant clinicopathological variables was observed. Our results clearly indicate the ability of both CS and ISET methods to detect CTCs in peripheral blood samples from ESCC patients. However, the CellSearch system appears to have a poorer sensitivity as compared with the ISET method. Further studies are essential for assessing the role of such technologies in ESCC.