Heparanase, the sole heparan sulfate (HS)-degrading endoglycosidase, regulates multiple biological activities that enhance tumor growth, metastasis, angiogenesis, and inflammation. Heparanase accomplishes this by degrading HS and thereby regulating the bioavailability of heparin-binding proteins; priming the tumor microenvironment; mediating tumor-host crosstalk; and inducing gene transcription, signaling pathways, exosome formation, and autophagy that together promote tumor cell performance and chemoresistance. By contrast, heparanase-2, a close homolog of heparanase, lacks enzymatic activity, inhibits heparanase activity, and regulates selected genes that promote normal differentiation, endoplasmic reticulum stress, tumor fibrosis, and apoptosis, together resulting in tumor suppression. The emerging premise is that heparanase is a master regulator of the aggressive phenotype of cancer, while heparanase-2 functions as a tumor suppressor.

Heparanase is an endoglycosidase that cleaves heparan sulfate side chains of proteoglycans, resulting in disassembly of the extracellular matrix underlying endothelial and epithelial cells and associating with enhanced cell invasion and metastasis. Heparanase expression is induced in carcinomas and sarcomas, often associating with enhanced tumor metastasis and poor prognosis. In contrast, the function of heparanase in hematological malignancies (except myeloma) was not investigated in depth. Here, we provide evidence that heparanase is expressed by human follicular and diffused non-Hodgkin's B-lymphomas, and that heparanase inhibitors restrain the growth of tumor xenografts produced by lymphoma cell lines. Furthermore, we describe, for the first time to our knowledge, the development and characterization of heparanaseneutralizing monoclonal antibodies that inhibit cell invasion and tumor metastasis, the hallmark of heparanase activity. Using luciferase-labeled Raji lymphoma cells, we show that the heparanase-neutralizing monoclonal antibodies profoundly inhibit tumor load in the mouse bones, associating with reduced cell proliferation and angiogenesis. Notably, we found that Raji cells lack intrinsic heparanase activity, but tumor xenografts produced by this cell line exhibit typical heparanase activity, likely contributed by host cells composing the tumor microenvironment. Thus, the neutralizing monoclonal antibodies attenuate lymphoma growth by targeting heparanase in the tumor microenvironment.heparanase | lymphoma | neutralizing antibody | tumor growth | metastasis H eparanase is an endo-β-D-glucuronidase capable of cleaving heparan sulfate (HS) side chains at a limited number of sites, releasing saccharide products with appreciable size (4-7 kDa) and biological potency. Enzymatic degradation of HS leads to disassembly of the extracellular matrix (ECM) and correlates with the metastatic potential of tumor-derived cells, attributed to enhanced cell dissemination as a consequence of HS cleavage and remodeling of the ECM and basement membrane underlying epithelial and endothelial cells (1, 2). Heparanase expression is induced in human cancer, most often associating with reduced patients' survival postoperation, increased tumor metastasis, and higher vessel density (3-5). In addition, heparanase up-regulation is associated with tumors larger in size (3, 5). Likewise, heparanase over-expression enhanced (6, 7), whereas local delivery of anti-heparanase siRNA inhibited (8), the growth of tumor xenografts. These results imply that heparanase function is not limited to tumor metastasis but is engaged in progression of the primary lesion, thus critically supporting the intimate involvement of heparanase in tumor progression and encouraging the development of heparanase inhibitors as anticancer therapeutics (9-12). As a consequence, heparanase inhibitors are currently evaluated in phase 1 clinical trials (13).Heparanase activity is similarly implicated in the progression of multiple myeloma (14-16), but its significan...

Recurrence of breast cancer disease years after treatment appears to arise from disseminated dormant tumor cells (DTC). The mechanisms underlying the outgrowth of DTC remain largely unknown. Here we demonstrate that dormant MCF-7 cells expressing LOXL2 acquire a cancer stem cell (CSC)-like phenotype, mediating their outgrowth in the 3D BME system that models tumor dormancy and outgrowth. Similarly, MCF-7-LOXL2 cells colonizing the lung transitioned from dormancy to metastatic outgrowth whereas MCF-7 cells remained dormant. Notably, epithelial to mesenchymal transition (EMT) of MCF-7-LOXL2 cells was required for their CSC-like properties and their transition to metastatic outgrowth. These findings were further supported by clinical data demonstrating that increase in LOXL2 mRNA levels correlates with increase in the mRNA levels of EMT and stem cells markers, and is also associated with decrease in relapse free survival of breast cancer patients. Notably, conditional hypoxia induced expression of endogenous LOXL2 in MCF-7 cells promoted EMT and the acquisition of a CSC-like phenotype, while knockdown of LOXL2 inhibited this transition. Overall, our results demonstrate that expression of LOXL2 endowed DTC with CSC-like phenotype driving their transition to metastatic outgrowth and this stem-like phenotype is dependent on EMT that can be driven by the tumor microenvironment.

Heparanase, the sole heparan sulfate degrading endoglycosidase, regulates multiple biological activities that enhance tumor growth, angiogenesis and metastasis. Much of the impact of heparanase on tumor progression is related to its function in mediating tumor-host crosstalk, priming the tumor microenvironment to better support tumor progression. Heparanase expression is enhanced in almost all cancers examined including various carcinomas, sarcomas and hematological malignancies. Numerous clinical association studies have consistently demonstrated that upregulated heparanase expression correlates with increased tumor size, tumor angiogenesis, enhanced metastasis and poor prognosis. Notably, heparanase is ranked among the most frequently recognized tumor antigens in patients with pancreatic, colorectal or breast cancer, favoring heparanase-based immunotherapy. Development of heparanase inhibitors focused on carbohydrate-based compounds of which 4 are being evaluated in clinical trials for various types of cancer, including myeloma, pancreatic carcinoma and hepatocellular carcinoma. Owing to their heparin-like nature, these compounds may exert off target effects. Newly generated heparanase neutralizing monoclonal antibodies profoundly attenuated myeloma and lymphoma tumor growth and dissemination in preclinical models, likely by targeting heparanase in the tumor microenvironment. KEYWORDSHeparanase; immunotherapy; lymphoma; neutralizing monoclonal antibody; tumor microenvironment Heparanase and cancerHeparan sulfate (HS) proteoglycans (HSPGs) are ubiquitous macromolecules associated with the cell surface and extracellular matrix (ECM) of a wide range of tissues.1 The HS chains bind to and assemble ECM proteins, thus playing important roles in ECM integrity, barrier function and cell-ECM interactions.1 HSPGs not only provide a storage depot for heparin-binding molecules (i.e., growth factors, chemokines, enzymes) in the tumor microenvironment, but also decisively regulate their accessibility, function and mode of action. It is therefore not surprising that a HS degrading enzyme (i.e., heparanase) is critically involved in tumor growth, angiogenesis and metastasis. Mammalian cells express a single dominant functional heparanase, an endoglycosidase that cleaves HS, leading to disassembly of the ECM and release of HS-bound bioactive molecules, thereby affecting tumor progression, angiogenesis and inflammation.2-4 The heparanase mRNA encodes a 65 kDa pro-enzyme that is cleaved by cathepsin L into 8 and 50 kDa subunits that non-covalently associate to form the active enzyme.5 Heparanase is up-regulated in essentially all human tumors examined, most often associating with reduced patients' survival post operation, increased tumor metastasis and higher vessel density.2,6,7 A causal role of heparanase in tumor metastasis was demonstrated by the increased lung, liver and bone colonization of cancer cells following over-expression of the heparanase gene, and by a marked decrease in the metastatic potential of cells s...

Heparanase is a mammalian endoglycosidase that cleaves heparan sulfate (HS) polysaccharides and contributes to remodelling of the extracellular matrix and regulation of HS-binding protein bioavailabilities. Heparanase is upregulated in malignant cancers and inflammation, aiding cell migration and the release of signaling molecules. It is established as a highly druggable extracellular target for anticancer therapy, but current compounds have limitations, because of cost, production complexity, or off-target effects. Here, we report the synthesis of a novel, targeted library of single-entity glycomimetic clusters capped with simple sulfated saccharides. Several dendrimer HS glycomimetics display low nM IC 50 potency for heparanase inhibition equivalent to comparator compounds in clinical development, and potently inhibit metastasis and growth of human myeloma tumor cells in a mouse xenograft model. Importantly, they lack anticoagulant activity and cytotoxicity, and also inhibit angiogenesis. They provide a new candidate class for anticancer and wider therapeutic applications, which could benefit from targeted heparanase inhibition.

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14One of the most frequent injury patterns leading to early death of polytraumatized 15 patients is hemorrhagic shock combined with traumatic brain injury. Currently, there 16 33 ml/kg of HTS or WB. Taken together, resuscitation with WB at 9-18ml/kg or HTS at 34 9ml/kg is optimal for treatment of combined injury. 3 35