fondaparinux and Neoplasm-Metastasis

Heparin has been used as an anticoagulant for decades. Recently, attention has been drawn to the non-anticoagulant activities of heparin. Experimentally and clinically those non-anticoagulant properties of heparin inhibit inflammation and metastatic spread of tumor cells. On the molecular level, heparin inhibits the function, expression and/or synthesis of adhesion molecules, cytokines, angiogenic factors and complement. However, despite a similar anticoagulant activity, those non-anticoagulant effects of heparin differ greatly among the different heparin preparations. The same holds true for the most common adverse events of heparin treatment. The incidence of immune mediated heparin-induced thrombocytopenia and cutaneous hypersensitivity responses is greatly, but not exclusively, influenced by the heparin preparation used. As the structure-function relationship of the anti-inflammatory and anti-metastatic effects of heparins are understood in more detail, and as the risk profile of different heparin preparations regarding the induction of adverse events have been identified, we propose to use the different heparin preparations according to the individual needs of each patient.

Topics: Angiogenesis Inhibitors; Anti-Inflammatory Agents, Non-Steroidal; Anticoagulants; Cell Adhesion Molecules; Clinical Trials as Topic; Complement Activation; Cytokines; Fondaparinux; Glucans; Heparin; Humans; Inflammation; Neoplasm Metastasis; Polysaccharides

The integrin VLA-4 is important for the metastatic dissemination of melanoma cells. We could recently show that heparin can block VLA-4 binding, which contributes, next to blocking P- and L-selectin, to the understanding of antimetastatic activities of heparin. The matricellular ligand Cyr61, secreted by numerous tumours, is responsible for increased tumourigenicity and metastasis. This has been attributed to Cyr61 binding to, and thus activating integrins. However, a VLA-4/Cyr61 axis has not yet been reported. Since Cyr61 possesses heparin binding capabilities, Cyr61 can be supposed as potential target for heparin to indirectly interfere with integrin functions. The present in vitro studies address (i) the existence of a Cyr61/VLA-4 axis and (ii) the functional relevance of heparin interference via Cyr61. The C-terminal module III of Cyr61 could be exposed as nanomolar affine binding site for VLA-4. A shRNA-based knockdown of Cyr61 in MV3 human melanoma cells reduced VLA-4-mediated cell binding to VCAM-1, migration on fibronectin, and integrin signalling functions significantly. Using a biosensor approach we provide insight into heparin interference with this process. The low-molecular-weight heparin tinzaparin, but not the pentasaccharide fondaparinux, binds module IV of Cyr61 with micromolar affinity. But tinzaparin cannot interfere with Cyr61 accumulation onto syndecan-4, indicating different Cyr61 binding sites for heparin and other GAGs. Nonetheless, tinzaparin affects the VLA-4 binding and signalling functions selectively via Cyr61 already at very low concentration most likely by blocking the cellular secreted free Cyr61. This study emphasises Cyr61 as promising, and hitherto not considered target for heparin to selectively influence integrin functions.

Topics: Anticoagulants; Carcinogenesis; Cell Adhesion; Cell Line, Tumor; Cell Movement; Cysteine-Rich Protein 61; Extracellular Matrix; Fondaparinux; Heparin; Heparin, Low-Molecular-Weight; Humans; Integrin alpha4beta1; Melanoma; Molecular Targeted Therapy; Neoplasm Metastasis; Polysaccharides; Protein Binding; RNA, Small Interfering; Syndecan-4; Tinzaparin

Long term anticoagulant therapy is recommended for treatment and secondary prevention of venous thromboembolism in cancer patients. We assessed outpatient anticoagulants [warfarin, low molecular weight heparins (LMWHs), fondaparinux and unfractionated heparin (UFH)] use in adult, cancer patients, 20years of age or older, who incurred a venous thromboembolism (primary or secondary in-hospital diagnosis) in Quebec, Canada between 2007 and 2009.. Data were obtained from the Quebec Health Insurance Agency. Patients with an in-hospital cancer diagnosis between April 2007 and June 2009 and an in-hospital venous thromboembolism diagnosis either concurrently or consequently were eligible at the date of discharge (index date). Those patients registered with the provincial drug plan and discharged to the community were included in the study and followed for 6months.. Among 2,070 study patients, 72.4% received anticoagulant therapy at index date, 60% of whom were persistent with therapy and received it for ≥80% of follow-up days. Outpatient anticoagulant use was more likely in those with primary versus secondary diagnosis of venous thromboembolism and less likely in patients with cerebrovascular disease, peptic ulcer disease or previous anticoagulant use. The small number of patients who used either UFH (n=11) or fondaparinux (n=5) at index date were included in the LMWH group. Warfarin use was less likely than LMWH use in corticosteroid users, previous anticoagulant users, patients with metastatic cancer and those with catheter or chemotherapy in the previous three months. Warfarin use was more likely than LMWH use in: older patients, those residing in rural areas, those with lower income and those suffering from ischemic heart disease, atrial fibrillation or chronic kidney disease. Patients with ischemic heart disease were more likely to have used a non-dalteparin LMWH versus dalteparin (currently, the only LMWH approved by health Canada for chronic treatment of VTE), while those residing in rural areas and those with catheter/chemotherapy were less likely to have used them. A primary (versus secondary) discharge diagnosis of venous thromboembolism [Odds Ratio 1.42; 95% confidence interval (1.14, 1.76)], and metastatic cancer 1.27 (1.00, 1.60) were associated with persistence on anticoagulant treatment.. Guideline recommended outpatient use of anticoagulant in cancer patients hospitalized with venous thromboembolism was influenced by cancer status, old age and low income. Risk factors for bleeding prevented outpatient anticoagulant use in some patients.

Topics: Adult; Aged; Anticoagulants; Cohort Studies; Female; Fondaparinux; Heparin; Heparin, Low-Molecular-Weight; Humans; Male; Middle Aged; Neoplasm Metastasis; Neoplasms; Odds Ratio; Polysaccharides; Retrospective Studies; Time Factors; Venous Thromboembolism; Warfarin

Heparin possesses antimetastatic effects that were related to various molecular mechanisms beyond anticoagulant activities. The ability of heparin to interfere with the function of adhesion receptors in the metastatic course appears as a promising therapeutic approach. This refers to numerous findings that heparin attenuates metastasis in a selectin-dependent manner. We recently demonstrated that heparin interferes with the integrin VLA-4 on murine melanoma cells binding to VCAM-1. To confirm this activity and to obtain further insight into molecular recognition of heparin by VLA-4, we investigated the inhibition of VLA-4 mediated binding of human melanoma MV3 cells to immobilised VCAM-1 by different heparins. The size of heparin has an important impact on inhibition. Unfractionated heparin (UFH) and tinzaparin, a low-molecular-weight heparin (LMWH) representing a mean of about 18-20 monomers, displayed high inhibitory activity. Fractionating tinzaparin to 14-18 monomers reduced inhibition slightly, while the pentasaccharide fondaparinux was without effects. To confirm molecular recognition of tinzaparin by VLA-4, a surface acoustic wave-biosensor was applied. A VLA-4 containing membrane preparation of MV3 cells was immobilised at the sensors to allow for detection of kinetic binding constants of tinzaparin compared to VCAM-1. Tinzaparin binds to VLA-4 with affinity in the low micromolar range (4.61 x 10(-6) M), which clearly indicates specific molecular recognition. Furthermore, tinzaparin displays a nearly identical k(off) compared to VCAM-1 (5.13 x 10(-3) s(-1) versus 3.44 x 10(-3) s(-1)) which is evident for interference with the ligand binding. The data provide evidence for a direct confirmation of heparin binding to VLA-4 and thus, contribute to understand the antimetastatic activity of heparin.

Topics: Acoustics; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Biosensing Techniques; Cell Adhesion; Cell Line; Cell Line, Tumor; Drug Screening Assays, Antitumor; Endothelial Cells; Fondaparinux; Heparin; Heparin, Low-Molecular-Weight; Humans; In Vitro Techniques; Integrin alpha4beta1; Melanoma; Natalizumab; Neoplasm Metastasis; P-Selectin; Polysaccharides; Recombinant Fusion Proteins; Rheology; Tinzaparin; Tumor Necrosis Factor-alpha; Vascular Cell Adhesion Molecule-1

Unfractionated heparin reduces metastasis in many murine models. Multiple mechanisms are proposed, particularly anticoagulation and/or inhibition of P-selectin and L-selectin. However, the doses used are not clinically tolerable and other heparins are now commonly used. We studied metastasis inhibition by clinically relevant levels of various heparins and investigated the structural basis for selectin inhibition differences.. Five clinically approved heparins were evaluated for inhibition of P-selectin and L-selectin binding to carcinoma cells. Pharmacokinetic studies determined optimal dosing for clinically relevant anticoagulant levels in mice. Experimental metastasis assays using carcinoma and melanoma cells investigated effects of a single injection of various heparins. Heparins were compared for structural relationships to selectin inhibition.. One (Tinzaparin) of three low molecular weight heparins showed increased selectin inhibitory activity, and the synthetic pentasaccharide, Fondaparinux, showed none when normalized to anticoagulant activity. Experimental metastasis models showed attenuation with unfractionated heparin and Tinzaparin, but not Fondaparinux, at clinically relevant anticoagulation levels. Tinzaparin has a small population of high molecular weight fragments not present in other low molecular weight heparins, enriched for selectin inhibitory activity.. Heparin can attenuate metastasis at clinically relevant doses, likely by inhibiting selectins. Equivalent anticoagulation alone with Fondaparinux is ineffective. Clinically approved heparins have differing abilities to inhibit selectins, likely explained by size distribution. It should be possible to size fractionate heparins and inhibit selectins at concentrations that do not have a large effect on coagulation. Caution is also raised about the current preference for smaller heparins. Despite equivalent anticoagulation, hitherto unsuspected benefits of selectin inhibition in various clinical circumstances may be unwittingly discarded.

Topics: Animals; Anticoagulants; Cell Line, Tumor; Disaccharides; Factor Xa; Fibrinolytic Agents; Fondaparinux; Heparin; Heparin, Low-Molecular-Weight; Kinetics; L-Selectin; Melanoma; Mice; Mice, Inbred C57BL; Neoplasm Metastasis; Oligosaccharides; P-Selectin; Polysaccharides; Protein Binding; Selectins; Sialyl Lewis X Antigen; Temperature; Thrombosis; Time Factors; Tinzaparin