Supersulfated low-molecular weight heparin synergizes with IGF1R/IR inhibitor to suppress synovial sarcoma growth and metastases

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].

Mast cell heparanase promotes breast cancer stem-like features via MUC1/estrogen receptor axis

Breast cancer is the most frequent type of tumor in women and is characterized by variable outcomes due to its heterogeneity and the presence of many cancer cell-autonomous and -non-autonomous factors. A major determinant of breast cancer aggressiveness is represented by immune infiltration, which can support tumor development. In our work, we studied the role of mast cells in breast cancer and identified a novel activity in promoting the tumor-initiating properties of cancer cells. Mast cells are known to affect breast cancer prognosis, but show different effects according to the diverse subtypes. Starting from the observation that co-injection of mast cells with limiting concentrations of cancer cells increased their in vivo engraftment rate, we characterized the molecular mechanisms by which mast cells promote the tumor stem-like features. We provide evidence that mast cell heparanase plays a pivotal role since both its activity and the stimulation of mast cells with heparan sulfate, the product of heparanase activity, are crucial for this process. Moreover, the pharmacological inhibition of heparanase prevents the function of mast cells. Our data show that soluble factors released by mast cells favor the expression of estrogen receptor in a MUC1-dependent manner. The MUC1/estrogen receptor axis is eventually essential for cancer stem-like features, specifically in HER2-negative cells, and promotes the capability of cancer cells to form mammospheres and express stem-related genes, also reducing their sensitivity to tamoxifen administration. Altogether our findings describe a novel mechanism by which mast cells could increase the aggressiveness of breast cancer uncovering a molecular mechanism displaying differences based on the specific breast cancer subtype.

Xenografting Human Musculoskeletal Sarcomas in Mice, Chick Embryo, and Zebrafish: How to Boost Translational Research

Musculoskeletal sarcomas pose major challenges to researchers and clinicians due to their rarity and heterogeneity. Xenografting human cells or tumor fragments in rodents is a mainstay for the generation of cancer models and for the preclinical trial of novel drugs. Lately, though, technical, intrinsic and ethical concerns together with stricter regulations have significantly curbed the employment of murine patient-derived xenografts (mPDX). In alternatives to murine PDXs, researchers have focused on embryonal systems such as chorioallantoic membrane (CAM) and zebrafish embryos. These systems are time- and cost-effective hosts for tumor fragments and near-patient cells. The CAM of the chick embryo represents a unique vascularized environment to host xenografts with high engraftment rates, allowing for ease of visualization and molecular detection of metastatic cells. Thanks to the transparency of the larvae, zebrafish allow for the tracking of tumor development and metastatization, enabling high-throughput drug screening. This review will focus on xenograft models of musculoskeletal sarcomas to highlight the intrinsic and technically distinctive features of the different hosts, and how they can be exploited to elucidate biological mechanisms beneath the different phases of the tumor's natural history and in drug development. Ultimately, the review suggests the combination of different models as an advantageous approach to boost basic and translational research.

Synovial Sarcoma Preclinical Modeling: Integrating Transgenic Mouse Models and Patient-Derived Models for Translational Research

Synovial sarcomas (SyS) are rare malignant tumors predominantly affecting children, adolescents, and young adults. The genetic hallmark of SyS is the t(X;18) translocation encoding the SS18-SSX fusion gene. The fusion protein interacts with both the BAF enhancer and polycomb repressor complexes, and either activates or represses target gene transcription, resulting in genome-wide epigenetic perturbations and altered gene expression. Several experimental in in vivo models, including conditional transgenic mouse models expressing the SS18-SSX fusion protein and spontaneously developing SyS, are available. In addition, patient-derived xenografts have been estab-lished in immunodeficient mice, faithfully reproducing the complex clinical heterogeneity. This review focuses on the main molecular features of SyS and the related preclinical in vivo and in vitro models. We will analyze the different conditional SyS mouse models that, after combination with some of the few other recurrent alterations, such as gains in BCL2, Wnt-β-catenin signaling, FGFR family, or loss of PTEN and SMARCB1, have provided additional insight into the mechanisms of synovial sarcomagenesis. The recent advancements in the understanding of SyS biology and improvements in preclinical modeling pave the way to the development of new epigenetic drugs and immunotherapeutic approaches conducive to new treatment options.

Upregulation of ERK-EGR1-heparanase axis by HDAC inhibitors provides targets for rational therapeutic intervention in synovial sarcoma

BACKGROUND

Synovial sarcoma (SS) is an aggressive soft tissue tumor with limited therapeutic options in advanced stage. SS18-SSX fusion oncogenes, which are the hallmarks of SS, cause epigenetic rewiring involving histone deacetylases (HDACs). Promising preclinical studies supporting HDAC targeting for SS treatment were not reflected in clinical trials with HDAC inhibitor (HDACi) monotherapies. We investigated pathways implicated in SS cell response to HDACi to identify vulnerabilities exploitable in combination treatments and improve the therapeutic efficacy of HDACi-based regimens.

METHODS

Antiproliferative and proapoptotic effects of the HDACi SAHA and FK228 were examined in SS cell lines in parallel with biochemical and molecular analyses to bring out cytoprotective pathways. Treatments combining HDACi with drugs targeting HDACi-activated prosurvival pathways were tested in functional assays in vitro and in a SS orthotopic xenograft model. Molecular mechanisms underlying synergisms were investigated in SS cells through pharmacological and gene silencing approaches and validated by qRT-PCR and Western blotting.

RESULTS

SS cell response to HDACi was consistently characterized by activation of a cytoprotective and auto-sustaining axis involving ERKs, EGR1, and the β-endoglycosidase heparanase, a well recognized pleiotropic player in tumorigenesis and disease progression. HDAC inhibition was shown to upregulate heparanase by inducing expression of the positive regulator EGR1 and by hampering negative regulation by p53 through its acetylation. Interception of HDACi-induced ERK-EGR1-heparanase pathway by cell co-treatment with a MEK inhibitor (trametinib) or a heparanase inhibitor (SST0001/roneparstat) enhanced antiproliferative and pro-apoptotic effects. HDAC and heparanase inhibitors had opposite effects on histone acetylation and nuclear heparanase levels. The combination of SAHA with SST0001 prevented the upregulation of ERK-EGR1-heparanase induced by the HDACi and promoted caspase-dependent cell death. In vivo, the combined treatment with SAHA and SST0001 potentiated the antitumor efficacy against the CME-1 orthotopic SS model as compared to single agent administration.

CONCLUSIONS

The present study provides preclinical rationale and mechanistic insights into drug combinatory strategies based on the use of ERK pathway and heparanase inhibitors to improve the efficacy of HDACi-based antitumor therapies in SS. The involvement of classes of agents already clinically available, or under clinical evaluation, indicates the transferability potential of the proposed approaches.

Unraveling the IGF System Interactome in Sarcomas Exploits Novel Therapeutic Options

Aberrant bioactivity of the insulin-like growth factor (IGF) system results in the development and progression of several pathologic conditions including cancer. Preclinical studies have shown promising anti-cancer therapeutic potentials for anti-IGF targeted therapies. However, a clear but limited clinical benefit was observed only in a minority of patients with sarcomas. The molecular complexity of the IGF system, which comprises multiple regulators and interactions with other cancer-related pathways, poses a major limitation in the use of anti-IGF agents and supports the need of combinatorial therapeutic strategies to better tackle this axis. In this review, we will initially highlight multiple mechanisms underlying IGF dysregulation in cancer and then focus on the impact of the IGF system and its complexity in sarcoma development and progression as well as response to anti-IGF therapies. We will also discuss the role of Ephrin receptors, Hippo pathway, BET proteins and CXCR4 signaling, as mediators of sarcoma malignancy and relevant interactors with the IGF system in tumor cells. A deeper understanding of these molecular interactions might provide the rationale for novel and more effective therapeutic combinations to treat sarcomas.

Heparanase Inhibitors in Cancer Progression: Recent Advances

BACKGROUND

An endo-β-glucuronidase enzyme, Heparanase (HPSE), degrades the side chains of polymeric heparan sulfate (HS), a glycosaminoglycan formed by alternate repetitive units of D-glucosamine and D-glucuronic acid/L-iduronic acid. HS is a major component of the extracellular matrix and basement membranes and has been implicated in processes of the tissue's integrity and functional state. The degradation of HS by HPSE enzyme leads to conditions like inflammation, angiogenesis, and metastasis. An elevated HPSE expression with a poor prognosis and its multiple roles in tumor growth and metastasis has attracted significant interest for its inhibition as a potential anti-neoplastic target.

METHODS

We reviewed the literature from journal publication websites and electronic databases such as Bentham, Science Direct, PubMed, Scopus, USFDA, etc., about HPSE, its structure, functions, and role in cancer.

RESULTS

The present review is focused on Heparanase inhibitors (HPIns) that have been isolated from natural resources or chemically synthesized as new therapeutics for metastatic tumors and chronic inflammatory diseases in recent years. The recent developments made in the HPSE structure and function are also discussed, which can lead to the future design of HPIns with more potency and specificity for the target.

CONCLUSION

HPIns can be a better target to be explored against various cancers.

Dichotomic role of heparanase in a murine model of metabolic syndrome

Heparanase is the predominant enzyme that cleaves heparan sulfate, the main polysaccharide in the extracellular matrix. While the role of heparanase in sustaining the pathology of autoimmune diabetes is well documented, its association with metabolic syndrome/type 2 diabetes attracted less attention. Our research was undertaken to elucidate the significance of heparanase in impaired glucose metabolism in metabolic syndrome and early type 2 diabetes. Here, we report that heparanase exerts opposite effects in insulin-producing (i.e., islets) vs. insulin-target (i.e., skeletal muscle) compartments, sustaining or hampering proper regulation of glucose homeostasis depending on the site of action. We observed that the enzyme promotes macrophage infiltration into islets in a murine model of metabolic syndrome, and fosters β-cell-damaging properties of macrophages activated in vitro by components of diabetogenic/obese milieu (i.e., fatty acids). On the other hand, in skeletal muscle (prototypic insulin-target tissue), heparanase is essential to ensure insulin sensitivity. Thus, despite a deleterious effect of heparanase on macrophage infiltration in islets, the enzyme appears to have beneficial role in glucose homeostasis in metabolic syndrome. The dichotomic action of the enzyme in the maintenance of glycemic control should be taken into account when considering heparanase-targeting strategies for the treatment of diabetes.

The Good and Bad Sides of Heparanase-1 and Heparanase-2

In this chapter, we will emphasize the importance of heparan sulfate proteoglycans (HSPG) in controlling various physiological and pathological molecular mechanisms and discuss how the heparanase enzyme can modulate the effects triggered by HSPG. Additionally, we will also navigate about the existing knowledge of the possible role of heparanase-2 in biological events. Heparan sulfate is widely distributed and evolutionarily conserved, evidencing its vital importance in cell development and functions such as cell proliferation, migration, adhesion, differentiation, and angiogenesis. During remodeling of the extracellular matrix, the breakdown of heparan sulfate by heparanase results in the release of molecules containing anchored glycosaminoglycan chains of great interest in heparanase-mediated cell signaling pathways in various physiological states, tumor development, inflammation, and other diseases. Taken together, it appears that heparanase plays a key role in the maintenance of the pathology of cancer and inflammatory diseases and is a potential target for anti-cancer therapies. Therefore, heparanase inhibitors are currently being examined in clinical trials as novel cancer therapeutics. Heparanase-2 has no enzymatic activity, displays higher affinity for heparan sulfate and the coding region alignment shows 40% identity with the heparanase gene. Heparanase-2 plays an important role in embryogenic development however its mode of action and biological function remain to be elucidated. Heparanase-2 functions as an inhibitor of the heparanase-1 enzyme and also inhibits neovascularization mediated by VEGF. The HPSE2 gene is repressed by the Polycomb complex, together suggesting a role as a tumor suppressor.

Antitumor activity and structure-activity relationship of heparanase inhibitors: Recent advances

Heparanase (HPSE)-directed tumor progression plays a crucial role in mediating tumor-host crosstalk and priming the tumor microenvironment, leading to tumor growth, metastasis and chemo-resistance. HPSE-mediated breakdown of structural heparan sulfate (HS) networks in the extracellular matrix (ECM) and basement membranes (BM) directly facilitates tumor growth and metastasis. Lysosome HPSE also induces multi-drug resistance via enhanced autophagy. Therefore, HPSE inhibitors development has become an attractive topic to block tumor growth and metastasis or eliminate drug resistance. In this review, we summarize HPSE inhibitors applied experimentally and clinically according to interaction with the binding sites of HPSE and participation of growth factors. The antitumor activity and structure-activity relationship (SAR) are also emphasized.

The Challenge of Modulating Heparan Sulfate Turnover by Multitarget Heparin Derivatives

This review comes as a part of the special issue "Emerging frontiers in GAGs and mimetics". Our interest is in the manipulation of heparan sulfate (HS) turnover by employing HS mimetics/heparin derivatives that exert pleiotropic effects and are interesting for interfering at multiple levels with pathways in which HS is implicated. Due to the important role of heparanase in HS post-biosynthetic modification and catabolism, we focus on the possibility to target heparanase, at both extracellular and intracellular levels, a strategy that can be applied to many conditions, from inflammation to cancer and neurodegeneration.

Roneparstat: Development, Preclinical and Clinical Studies

A growing interest around heparanase and its role in cancer, inflammation and other diseases prompted the identification of specific inhibitors of this enzyme and the exploration of their potential therapeutic role. Roneparstat, a 15-25 kDa N-acetylated and glycol split heparin, is one of the most potent and widely studied heparanase inhibitors. These studies generated a large body of data, which allowed to characterize Roneparstat properties and to endorse its potential therapeutic role. Multiple Myeloma represents the indication that most of the studies, including the phase I clinical trial, addressed. However, Roneparstat antitumor activity activity has been documented in other cancers, and in non-oncological conditions.In addition, assessing Roneparstat activity in different experimental models contributed to understanding heparanase role and the biological factors that may be affected by heparanase inhibition in more detail. Finally, some studies elucidated the molecular mechanisms regulating the enzyme-inhibitor kinetics, thus providing important data for the identification and design of new inhibitors.The objective of this chapter is to provide a comprehensive overview of the most significant studies involving Roneparstat and discuss its potential role in therapy.

Heparanase: A Potential Therapeutic Target in Sarcomas

Sarcomas comprise a heterogeneous group of rare malignancies of mesenchymal origin including more than 70 subtypes. They may arise in muscle, bone, cartilage and other connective tissues. Their high histological and genetic heterogeneity makes diagnosis and treatment very challenging. Deregulation of heparanase has been found in several sarcoma subtypes and high expression levels have been correlated with poor prognosis in Ewing's sarcoma and osteosarcoma. Altered expression of specific heparan sulfate proteoglycans and heparan sulfate biosynthetic enzymes has also been observed. Advances in molecular pathogenesis of sarcomas have evidenced the critical role of several heparan sulfate binding growth factors and receptor tyrosine kinases, highly interconnected with the microenvironment, in sustaining tumor growth and progression. Interference with heparanase/heparan sulfate functions represents a potential therapeutic approach in sarcoma. In this chapter, we summarize the current knowledge about the biological significance of heparanase expression and its potential as a therapeutic target in subtypes of both soft tissue and bone sarcomas. Particular emphasis is given to the involvement of heparan sulfate proteoglycans and their synthesizing and modifying enzymes in bone physiology and disorders leading up to the pathobiology of bone sarcomas. The chapter also describes the cooperation between exostin loss-of-function and heparanase upregulation in hereditary Multiple Osteochondroma syndrome as a paradigmatic example of constitutive alteration of the heparanase/heparan sulfate proteoglycan system which may contribute to progression to malignant secondary chondrosarcoma. Preclinical evidence of the role of heparanase as a promising therapeutic target in various sarcoma subtypes is finally resumed.

Non-Anticoagulant Heparins as Heparanase Inhibitors

The chapter will review early and more recent seminal contributions to the discovery and characterization of heparanase and non-anticoagulant heparins inhibiting its peculiar enzymatic activity. Indeed, heparanase displays a unique versatility in degrading heparan sulfate chains of several proteoglycans expressed in all mammalian cells. This endo-β-D-glucuronidase is overexpressed in cancer, inflammation, diabetes, atherosclerosis, nephropathies and other pathologies. Starting from known low- or non-anticoagulant heparins, the search for heparanase inhibitors evolved focusing on structure-activity relationship studies and taking advantage of new chemical-physical analytical methods which have allowed characterization and sequencing of polysaccharide chains. New methods to screen heparanase inhibitors and to evaluate their mechanism of action and in vivo activity in experimental models prompted their development. New non-anticoagulant heparin derivatives endowed with anti-heparanase activity are reported. Some leads are under clinical evaluation in the oncology field (e.g., acute myeloid leukemia, multiple myeloma, pancreatic carcinoma) and in other pathological conditions (e.g., sickle cell disease, malaria, labor arrest).

Targeting the undruggable: exploiting neomorphic features of fusion oncoproteins in childhood sarcomas for innovative therapies

While sarcomas account for approximately 1% of malignant tumors of adults, they are particularly more common in children and adolescents affected by cancer. In contrast to malignancies that occur in later stages of life, childhood tumors, including sarcoma, are characterized by a striking paucity of somatic mutations. However, entity-defining fusion oncogenes acting as the main oncogenic driver mutations are frequently found in pediatric bone and soft-tissue sarcomas such as Ewing sarcoma (EWSR1-FLI1), alveolar rhabdomyosarcoma (PAX3/7-FOXO1), and synovial sarcoma (SS18-SSX1/2/4). Since strong oncogene-dependency has been demonstrated in these entities, direct pharmacological targeting of these fusion oncogenes has been excessively attempted, thus far, with limited success. Despite apparent challenges, our increasing understanding of the neomorphic features of these fusion oncogenes in conjunction with rapid technological advances will likely enable the development of new strategies to therapeutically exploit these neomorphic features and to ultimately turn the "undruggable" into first-line target structures. In this review, we provide a broad overview of the current literature on targeting neomorphic features of fusion oncogenes found in Ewing sarcoma, alveolar rhabdomyosarcoma, and synovial sarcoma, and give a perspective for future developments. Graphical abstract Scheme depicting the different targeting strategies of fusion oncogenes in pediatric fusion-driven sarcomas. Fusion oncogenes can be targeted on their DNA level (1), RNA level (2), protein level (3), and by targeting downstream functions and interaction partners (4).

Targeting Heparanase in Cancer: Inhibition by Synthetic, Chemically Modified, and Natural Compounds

Heparanase is an endoglycosidase involved in remodeling the extracellular matrix and thereby in regulating multiple cellular processes and biological activities. It cleaves heparan sulfate (HS) side chains of HS proteoglycans into smaller fragments and hence regulates tissue morphogenesis, differentiation, and homeostasis. Heparanase is overexpressed in various carcinomas, sarcomas, and hematological malignancies, and its upregulation correlates with increased tumor size, tumor angiogenesis, enhanced metastasis, and poor prognosis. In contrast, knockdown or inhibition of heparanase markedly attenuates tumor progression, further underscoring the potential of anti-heparanase therapy. Heparanase inhibitors were employed to interfere with tumor progression in preclinical studies, and selected heparin mimetics are being examined in clinical trials. However, despite tremendous efforts, the discovery of heparanase inhibitors with high clinical benefit and minimal adverse effects remains a therapeutic challenge. This review discusses the key roles of heparanase in cancer progression focusing on the status of natural, chemically modified, and synthetic heparanase inhibitors in various types of malignancies.

The non-anticoagulant promise of heparin and its mimetics

Heparin, the widely used anticoagulant and antithrombotic polysaccharide, has other potential therapeutic uses that arise from its similarity to heparan sulfate. This review provides a brief overview of the most recent developments in this field, paying particular respect to pulmonary and respiratory pharmacology. It has often been said that heparin, with its mimetics and derivatives, shows great promise in the treatment of inflammatory, infectious, and malignant conditions. Difficulties are encountered, however, in translating this promise into worthwhile treatment strategies for patients in some conditions. Several clinical trials of low molecular weight heparins as adjuvant therapy to standard treatment of lung cancers have recently provided no evidence to support the supposed beneficial effects of low molecular weight heparin.

Overactive IGF1/Insulin Receptors and NRASQ61R Mutation Drive Mechanisms of Resistance to Pazopanib and Define Rational Combination Strategies to Treat Synovial Sarcoma

Pazopanib is approved for treatment of advanced soft tissue sarcomas, but primary and secondary drug resistance limits its clinical utility. We investigated the molecular mechanisms mediating pazopanib resistance in human synovial sarcoma (SS) models. We found reduced cell sensitivity to pazopanib associated with inefficient inhibition of the two critical signaling nodes, AKT and ERKs, despite strong inhibition of the main drug target, PDGFRα. In the CME-1 cell line, overactivation of IGF1 and Insulin receptors (IGF1R/InsR) sustained AKT activation and pazopanib resistance, which was overcome by a combination treatment with the double IGF1R/InsR inhibitor BMS754807. In the highly pazopanib resistant MoJo cell line, NRASQ61R mutation sustained constitutive ERK activation. Transfection of the NRAS mutant in the pazopanib sensitive SYO-1 cell line increased the drug IC₅₀. MoJo cells treatment with pazopanib in combination with the MEK inhibitor trametinib restored ERK inhibition, synergistically inhibited cell growth, and induced apoptosis. The combination significantly enhanced the antitumor efficacy against MoJo orthotopic xenograft abrogating growth in 38% of mice. These findings identified two different mechanisms of intrinsic pazopanib resistance in SS cells, supporting molecular/immunohistochemical profiling of tumor specimens as a valuable approach to selecting patients who may benefit from rational drug combinations.

Novel Symmetrical Benzazolyl Derivatives Endowed with Potent Anti-Heparanase Activity

Heparanase is the only mammalian endo-β-d-glucuronidase involved in a variety of major diseases. The up-regulation of heparanase expression increases tumor size, angiogenesis, and metastasis, representing a validated target in the anti-cancer field. To date, only a few small-molecule inhibitors have been described, but none have gotten through pre-clinical development. Previously, we explored 2-(4-(4-(bromo-methoxybenzamido)benzylamino)phenyl) benzazole derivatives as anti-heparanase agents, proposing this scaffold for development of broadly effective heparanase inhibitors. Herein, we report an extended investigation of new symmetrical 2-aminophenyl-benzazolyl-5-acetate derivatives, proving that symmetrical compounds are more effective than asymmetrical analogues, with the most-potent compound, 7g, being active at nanomolar concentration against heparanase. Molecular docking studies were performed on the best-acting compounds 5c and 7g to rationalize their interaction with the enzyme. Moreover, invasion assay confirmed the anti-metastatic potential of compounds 5c, 7a, and 7g, proving the inhibition of the expression of proangiogenic factors in tumor cells.

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.

Novel Benzazole Derivatives Endowed with Potent Antiheparanase Activity

Heparanase is the sole mammalian enzyme capable of cleaving glycosaminoglycan heparan sulfate side chains of heparan sulfate proteoglycans. Its altered activity is intimately associated with tumor growth, angiogenesis, and metastasis. Thus, its implication in cancer progression makes it an attractive target in anticancer therapy. Herein, we describe the design, synthesis, and biological evaluation of new benzazoles as heparanase inhibitors. Most of the designed derivatives were active at micromolar or submicromolar concentration, and the most promising compounds are fluorinated and/or amino acids derivatives 13a, 14d, and 15 that showed IC₅₀ 0.16-0.82 μM. Molecular docking studies were performed to rationalize their interaction with the enzyme catalytic site. Importantly, invasion assay confirmed the antimetastatic potential of compounds 14d and 15. Consistently with its ability to inhibit heparanase, compound 15 proved to decrease expression of genes encoding for proangiogenic factors such as MMP-9, VEGF, and FGFs in tumor cells.

Low-Molecular-Weight Heparins: Reduced Size Particulate Systems for Improved Therapeutic Outcomes

A wide range of diseases have been treated using low-molecular-weight heparins (LMWHs), the drug of choice for anticoagulation. Owing to their better pharmacokinetic features compared to those of unfractionated heparin (uFH), several systems incorporating LMWHs have been investigated to deliver and improve their therapeutic outcomes, especially through development of their micro- and nano-particles. This review article describes current perspectives on the fabrication, characterization, and application of LMWHs-loaded micro- and nano-particles to achieve ameliorated bioavailability. The valuable applications of LMWH will continue to encourage researchers to identify efficient delivery systems that have specific release characteristics and ameliorated bioavailability, overcoming the challenges presented by biological obstructions and the physicochemical properties of LMWHs.