Heparanase in Cancer Metastasis – Heparin as a Potential Inhibitor of Cell Adhesion Molecules. In: Vlodavsky I, Sanderson RD, Ilan N, editors. Heparanase. Cham: Springer International Publishing; 2020. pp. 309-29. [DOI: 10.1007/978-3-030-34521-1_11]

Direct antitumoral effects of sulfated fucans isolated from echinoderms: a possible role of neuropilin-1/β1 integrin endocytosis and focal adhesion kinase degradation

Hypercoagulability, a major complication of metastatic cancers, has usually been treated with heparins from natural sources, or with their synthetic derivatives, which are under intense investigation in clinical oncology. However, the use of heparin has been challenging for patients with risk of severe bleeding. While the systemic administration of heparins, in preclinical models, has shown primarily attenuating effects on metastasis, their direct effect on established solid tumors has generated contradictory outcomes. We investigated the direct antitumoral properties of two sulfated fucans isolated from marine echinoderms, FucSulf1 and FucSulf2, which exhibit anticoagulant activity with mild hemorrhagic potential. Unlike heparin, sulfated fucans significantly inhibited tumor cell proliferation (by ~30-50%), and inhibited tumor migration and invasion in vitro. We found that FucSulf1 and FucSulf2 interacted with fibronectin as efficiently as heparin, leading to loss of prostate cancer and melanoma cell spreading. The sulfated fucans increased the endocytosis of β1 integrin and neuropilin-1 chains, two cell receptors implicated in fibronectin-dependent adhesion. The treatment of cancer cells with both sulfated fucans, but not with heparin, also triggered intracellular focal adhesion kinase (FAK) degradation, with a consequent overall decrease in activated focal adhesion kinase levels. Finally, only sulfated fucans inhibited the growth of B16-F10 melanoma cells implanted in the dermis of syngeneic C57/BL6 mice. FucSulf1 and FucSulf2 arise from this study as candidates for the design of possible alternatives to long-term treatments of cancer patients with heparins, with the advantage of also controlling local growth and invasion of malignant cells.

Extension of the SUGRES-1P Coarse-Grained Model of Polysaccharides to Heparin

Heparin is an unbranched periodic polysaccharide composed of negatively charged monomers and involved in key biological processes, including anticoagulation, angiogenesis, and inflammation. Its structure and dynamics have been studied extensively using experimental as well as theoretical approaches. The conventional approach of computational chemistry applied to the analysis of biomolecules is all-atom molecular dynamics, which captures the interactions of individual atoms by solving Newton's equation of motion. An alternative is molecular dynamics simulations using coarse-grained models of biomacromolecules, which offer a reduction of the representation and consequently enable us to extend the time and size scale of simulations by orders of magnitude. In this work, we extend the UNIfied COarse-gRaiNed (UNICORN) model of biological macromolecules developed in our laboratory to heparin. We carried out extensive tests to estimate the optimal weights of energy terms of the effective energy function as well as the optimal Debye-Hückel screening factor for electrostatic interactions. We applied the model to study unbound heparin molecules of polymerization degree ranging from 6 to 68 residues. We compare the obtained coarse-grained heparin conformations with models obtained from X-ray diffraction studies of heparin. The SUGRES-1P force field was able to accurately predict the general shape and global characteristics of heparin molecules.

A Novel Approach to Reducing Lung Metastasis in Osteosarcoma: Increasing Cell Stiffness with Carbenoxolone

AIM

Primary malignant bone tumor osteosarcoma can metastasize to the lung. Diminishing lung metastasis would positively affect the prognosis of patients. Our previous studies demonstrated that highly metastatic osteosarcoma cell lines are significantly softer than low-metastasis cell lines. We therefore hypothesized that increasing cell stiffness would suppress metastasis by reducing cell motility. In this study, we tested whether carbenoxolone (CBX) increases the stiffness of LM8 osteosarcoma cells and prevents lung metastasis in vivo.

METHODS

We evaluated the actin cytoskeletal structure and polymerization of CBX-treated LM8 cells using actin staining. Cell stiffness was measured using atomic force microscopy. Metastasis-related cell functions were analyzed using cell proliferation, wound healing, invasion, and cell adhesion assays. Furthermore, lung metastasis was examined in LM8-bearing mice administered with CBX.

RESULTS

Treatment with CBX significantly increased actin staining intensity and stiffness of LM8 cells compared with vehicle-treated LM8 cells (p < 0.01). In Young's modulus images, compared with the control group, rigid fibrillate structures were observed in the CBX treatment group. CBX suppressed cell migration, invasion, and adhesion but not cell proliferation. The number of LM8 lung metastases were significantly reduced in the CBX administration group compared with the control group (p < 0.01).

CONCLUSION

In this study, we demonstrated that CBX increases tumor cell stiffness and significantly reduces lung metastasis. Our study is the first to provide evidence that reducing cell motility by increasing cell stiffness might be effective as a novel anti-metastasis approach in vivo.

Physcion, a novel anthraquinone derivative against Chlamydia psittaci infection

Physcion, a natural anthraquinone derivative, has been reported to exert remarkable antibacterial activities against Staphylococcus aureus,Staphylococcus epidermidis and Pseudomonas aeruginosa. However, it is not fully illustrated as anti-Chlamydia substance. In the present study, minimum inhibitory concentration(MIC)values for physcion against Chlamydia psittaci(C.psittaci) 6BC, C.psittaci SBL and C.psittaci HJ were 128 μg/mL,256 μg/mL and 128 μg/mL while minimum bactericidal concentration (MBC) values were 256 μg/mL,512 μg/mL and 256 μg/mL,respectively. Moreover, Chlamydial adhesion to Hela 229 cells was blocked in a dose-dependent manner and RB-to-EB differentiation was inhibited by physcion from 28 to 48 hpi.Post treatment,upregulation of LC3-II was in a dose-dependent manner, indicating physcion activated autophagy and bacterial clearance.To validate clinical efficacy,49 SPF chickens aged 21days were divided into 5 groups and infected intra-laryngeally with 0.2 mL of 1 × 10⁷ IFU/mL C.psittaci 6 BCE.Three days later, birds received orally with serial doses of physcion (4 mg/kg to 9 mg/kg), or 3 mg/kg of doxycycline for 6 days.Chickens with difficulty in breathing were alleviated significantly with increasing concentrations of physicon.Postmortem,lesions of air sacs were reduced significantly in a dose-dependent manner.More importantly,birds with 9 mg/kg of physcion could alleviate lesions of air sacs and lungs, and reduce bacterial loads in spleens, which was comparable to doxycycline treatment. Based on above evidences, physcion is a promising cost-effective natural drug by blocking Chlamydial adhesions to host cells, RB-to-EB differentiation and activating bacterial autophagy and it will be a good alternative to doxycycline combating virulent C.psittaci infection, contributing to eradication of Chlamydial transmission from animals to human beings.

Pharmacology of Heparin and Related Drugs: An Update

Heparin has been used extensively as an antithrombotic and anticoagulant for close to 100 years. This anticoagulant activity is attributed mainly to the pentasaccharide sequence, which potentiates the inhibitory action of antithrombin, a major inhibitor of the coagulation cascade. More recently it has been elucidated that heparin exhibits anti-inflammatory effect via interference of the formation of neutrophil extracellular traps and this may also contribute to heparin's antithrombotic activity. This illustrates that heparin interacts with a broad range of biomolecules, exerting both anticoagulant and nonanticoagulant actions. Since our previous review, there has been an increased interest in these nonanticoagulant effects of heparin, with the beneficial role in patients infected with SARS2-coronavirus a highly topical example. This article provides an update on our previous review with more recent developments and observations made for these novel uses of heparin and an overview of the development status of heparin-based drugs. SIGNIFICANCE STATEMENT: This state-of-the-art review covers recent developments in the use of heparin and heparin-like materials as anticoagulant, now including immunothrombosis observations, and as nonanticoagulant including a role in the treatment of SARS-coronavirus and inflammatory conditions.

Pathogen Moonlighting Proteins: From Ancestral Key Metabolic Enzymes to Virulence Factors

Moonlighting and multitasking proteins refer to proteins with two or more functions performed by a single polypeptide chain. An amazing example of the Gain of Function (GoF) phenomenon of these proteins is that 25% of the moonlighting functions of our Multitasking Proteins Database (MultitaskProtDB-II) are related to pathogen virulence activity. Moreover, they usually have a canonical function belonging to highly conserved ancestral key functions, and their moonlighting functions are often involved in inducing extracellular matrix (ECM) protein remodeling. There are three main questions in the context of moonlighting proteins in pathogen virulence: (A) Why are a high percentage of pathogen moonlighting proteins involved in virulence? (B) Why do most of the canonical functions of these moonlighting proteins belong to primary metabolism? Moreover, why are they common in many pathogen species? (C) How are these different protein sequences and structures able to bind the same set of host ECM protein targets, mainly plasminogen (PLG), and colonize host tissues? By means of an extensive bioinformatics analysis, we suggest answers and approaches to these questions. There are three main ideas derived from the work: first, moonlighting proteins are not good candidates for vaccines. Second, several motifs that might be important in the adhesion to the ECM were identified. Third, an overrepresentation of GO codes related with virulence in moonlighting proteins were seen.

Inhibition of Tumor-Host Cell Interactions Using Synthetic Heparin Mimetics

Low-molecular-weight heparin (LMWH) is the guideline-based drug for antithrombotic treatment of cancer patients, while its direct antitumor effects are a matter of ongoing debate. Although therapeutically established for decades, LMWH has several drawbacks mainly associated with its origin from animal sources. Aiming to overcome these limitations, a library of synthetic heparin mimetic polymers consisting of homo- and copolymers of sulfonated and carboxylated noncarbohydrate monomers has recently been synthesized via reversible addition-fragmentation chain transfer polymerization. These heparin mimetics were investigated for their capacities to interfere with simulated steps of tumor cell metastasis. Among them, homo- and copolymers from sodium 4-styrenesulfonate (poly(SSS)) with acrylic acid (poly(SSS-co-AA)) with an MW between 5 and 50 kDa efficiently attenuated cancer cell-induced coagulation and thus platelet activation and degranulation similar to or even better than LMWH. Furthermore, independent of anticoagulant activities, these polymers affected other metastasis-relevant targets with impressive affinities. Hence, they blocked heparanase enzymatic activity outmatching commercial heparins or a glycosidic drug candidate. Furthermore, these polymers bind P-selectin and the integrin VLA-4 similar to or even better than heparin, indicated by a biosensor approach and thus efficiently blocked melanoma cell binding to endothelium under blood flow conditions. This is the first report on the prospects of synthetic heparin mimetics as promising nontoxic compounds in oncology to potentially substitute heparin as an anticoagulant and to better understand its role as an antimetastatic drug.

Review: Inhibitory potential of low molecular weight Heparin in cell adhesion; emphasis on tumor metastasis

Low molecular weight heparin is a Heparin derivative, produced from commercial-grade Heparin through Chemical or enzymatic depolymerization. LMWH has remained a favored regimen for anticoagulation in cancer patients. Evidence from several studies has suggested that LMWHs possess antitumor and antimetastatic activity aside from their anticoagulant activity. Cancer metastasis is the foremost reason for cancer-related motility rate. Studies have pointed out that adhesion molecules play a decisive role in enhancing recurrent, invasive, and distant metastasis. Therefore, it is hypothesized that Cell adhesion molecules can be determined as a potential therapeutic target group, as antibodies or small-molecule inhibitors could easily access their extracellular domains. Furthermore, data from several investigations have reported LWMH potential effects as antimetastatic agents through influencing cell adhesion molecules. This review's objective is to emphasize the evidence available for the effects of the LMWHs in cell adhesion to inhibit tumor metastasis.