Elevated serum heparanase-1 levels in patients with pancreatic carcinoma are associated with poor survival

Design of an Ultralow Molecular Weight Heparin That Resists Heparanase Biodegradation

Heparanase, an endo-β-d-glucuronidase produced by a variety of cells and tissues, cleaves the glycosidic linkage between glucuronic acid (GlcA) and a 3-O- or 6-O-sulfated glucosamine, typified by the disaccharide -[GlcA-GlcNS3S6S]-, which is found within the antithrombin-binding domain of heparan sulfate or heparin. As such, all current forms of heparin are susceptible to degradation by heparanase with neutralization of anticoagulant properties. Here, we have designed a heparanase-resistant, ultralow molecular weight heparin as the structural analogue of fondaparinux that does not contain an internal GlcA residue but otherwise displays potent anticoagulant activity. This heparin oligosaccharide was synthesized following a chemoenzymatic scheme and displays nanomolar anti-FXa activity yet is resistant to heparanase digestion. Inhibition of thrombus formation was further demonstrated after subcutaneous administration of this compound in a murine model of venous thrombosis. Thrombus inhibition was comparable to that observed for enoxaparin with a similar effect on bleeding time.

Osteochondroma formation is independent of heparanase expression as revealed in a mouse model of hereditary multiple exostoses

Hereditary multiple exostoses (HME) is a rare, pediatric disorder characterized by osteochondromas that form along growth plates and provoke significant musculoskeletal problems. HME is caused by mutations in heparan sulfate (HS)-synthesizing enzymes EXT1 or EXT2. Seemingly paradoxically, osteochondromas were found to contain excessive extracellular heparanase (Hpse) that could further reduce HS levels and exacerbate pathogenesis. To test Hpse roles, we asked whether its ablation would protect against osteochondroma formation in a conditional HME model consisting of mice bearing floxed Ext1 alleles in Agr-CreER background (Ext1f/f ;Agr-CreER mice). Mice were crossed with a new global Hpse-null (Hpse-/- ) mice to produce compound Hpse-/- ;Ext1f/f ;Agr-CreER mice. Tamoxifen injection of standard juvenile Ext1f/f ;Agr-CreER mice elicited stochastic Ext1 ablation in growth plate and perichondrium, followed by osteochondroma formation, as revealed by microcomputed tomography and histochemistry. When we examined companion conditional Ext1-deficient mice lacking Hpse also, we detected no major decreases in osteochondroma number, skeletal distribution, and overall structure by the analytical criteria above. The Ext1 mutants used here closely mimic human HME pathogenesis, but have not been previously tested for responsiveness to treatments. To exclude some innate therapeutic resistance in this stochastic model, tamoxifen-injected Ext1f/f ;Agr-CreER mice were administered daily doses of the retinoid Palovarotene, previously shown to prevent ectopic cartilage and bone formation in other mouse disease models. This treatment did inhibit osteochondroma formation compared with vehicle-treated mice. Our data indicate that heparanase is not a major factor in osteochondroma initiation and accumulation in mice. Possible roles of heparanase upregulation in disease severity in patients are discussed.

Heparanase 1 Upregulation Promotes Tumor Progression and Is a Predictor of Low Survival for Oral Cancer

Background: Oral cavity cancer is still an important public health problem throughout the world. Oral squamous cell carcinomas (OSCCs) can be quite aggressive and metastatic, with a low survival rate and poor prognosis. However, this is usually related to the clinical stage and histological grade, and molecular prognostic markers for clinical practice are yet to be defined. Heparanase (HPSE1) is an endoglycosidase associated with extracellular matrix remodeling, and although involved in several malignancies, the clinical implications of HPSE1 expression in OSCCs are still unknown.

Methods: We sought to investigate HPSE1 expression in a series of primary OSCCs and further explore whether its overexpression plays a relevant role in OSCC tumorigenesis. mRNA and protein expression analyses were performed in OSCC tissue samples and cell lines. A loss-of-function strategy using shRNA and a gain-of-function strategy using an ORF vector targeting HPSE1 were employed to investigate the endogenous modulation of HPSE1 and its effects on proliferation, apoptosis, adhesion, epithelial–mesenchymal transition (EMT), angiogenesis, migration, and invasion of oral cancer in vitro.

Results: We demonstrated that HPSE1 is frequently upregulated in OSCC samples and cell lines and is an unfavorable prognostic indicator of disease-specific survival when combined with advanced pT stages. Moreover, abrogation of HPSE1 in OSCC cells significantly promoted apoptosis and inhibited proliferation, migration, invasion, and epithelial–mesenchymal transition by significantly decreasing the expression of N-cadherin and vimentin. Furthermore, a conditioned medium of HPSE1-downregulated cells resulted in reduced vascular endothelial growth.

Conclusion: Our results confirm the overexpression of HPSE1 in OSCCs, suggest that HPSE1 expression correlates with disease progression as it is associated with several important biological processes for oral tumorigenesis, and can be managed as a prognostic marker for patients with OSCC.

Key Matrix Remodeling Enzymes: Functions and Targeting in Cancer

Tissue functionality and integrity demand continuous changes in distribution of major components in the extracellular matrices (ECMs) under normal conditions aiming tissue homeostasis. Major matrix degrading proteolytic enzymes are matrix metalloproteinases (MMPs), plasminogen activators, atypical proteases such as intracellular cathepsins and glycolytic enzymes including heparanase and hyaluronidases. Matrix proteases evoke epithelial-to-mesenchymal transition (EMT) and regulate ECM turnover under normal procedures as well as cancer cell phenotype, motility, invasion, autophagy, angiogenesis and exosome formation through vital signaling cascades. ECM remodeling is also achieved by glycolytic enzymes that are essential for cancer cell survival, proliferation and tumor progression. In this article, the types of major matrix remodeling enzymes, their effects in cancer initiation, propagation and progression as well as their pharmacological targeting and ongoing clinical trials are presented and critically discussed.

PI-88 and Related Heparan Sulfate Mimetics

The heparan sulfate mimetic PI-88 (muparfostat) is a complex mixture of sulfated oligosaccharides that was identified in the late 1990s as a potent inhibitor of heparanase. In preclinical animal models it was shown to block angiogenesis, metastasis and tumor growth, and subsequently became the first heparanase inhibitor to enter clinical trials for cancer. It progressed to Phase III trials but ultimately was not approved for use. Herein we summarize the preparation, physicochemical and biological properties of PI-88, and discuss preclinical/clinical and structure-activity relationship studies. In addition, we discuss the PI-88-inspired development of related HS mimetic heparanase inhibitors with improved properties, ultimately leading to the discovery of PG545 (pixatimod) which is currently in clinical trials.

Involvement of Syndecan-1 and Heparanase in Cancer and Inflammation

The cell surface heparan sulfate proteoglycan Syndecan-1 acts as an important co-receptor for receptor tyrosine kinases and chemokine receptors, and as an adhesion receptor for structural glycoproteins of the extracellular matrix. It serves as a substrate for heparanase, an endo-β-glucuronidase that degrades specific domains of heparan sulfate carbohydrate chains and thereby alters the functional status of the proteoglycan and of Syndecan-1-bound ligands. Syndecan-1 and heparanase show multiple levels of functional interactions, resulting in mutual regulation of their expression, processing, and activity. These interactions are of particular relevance in the context of inflammation and malignant disease. Studies in animal models have revealed a mechanistic role of Syndecan-1 and heparanase in the regulation of contact allergies, kidney inflammation, multiple sclerosis, inflammatory bowel disease, and inflammation-associated tumorigenesis. Moreover, functional interactions between Syndecan-1 and heparanase modulate virtually all steps of tumor progression as defined in the Hallmarks of Cancer. Due to their prognostic value in cancer, and their mechanistic involvement in tumor progression, Syndecan-1 and heparanase have emerged as important drug targets. Data in preclinical models and preclinical phase I/II studies have already yielded promising results that provide a translational perspective.

The HPA/SDC1 axis promotes invasion and metastasis of pancreatic cancer cells by activating EMT via FGF2 upregulation

Pancreatic cancer is characterized by the absence of early specific clinical symptoms, accompanied with rapid metastasis and invasion. It is one of the most prevalent types of cancer and more importantly, one of the most common types of malignant cancer with the highest mortality rate of all cancer types. The heparanase (HPA)/syndecan-1 (SDC1) axis has been reported to promote tumor growth, invasion, metastasis and angiogenesis in a variety of cancer types; however, studies into the role and mechanism of the HPA/SDC1 axis in pancreatic cancer are limited. The present study aimed to investigate the biological function and clinical significance of the HPA/SDC1 axis in pancreatic cancer. The results demonstrated that HPA is elevated in pancreatic cancer tissues and cell lines, and that its high expression was associated with poor prognosis. HPA was revealed to mediate an increase in fibroblast growth factor 2 (FGF2) expression by upregulating the expression of SDC1. Conversely, silencing HPA mediated the suppression of FGF2 expression. Furthermore, upregulated FGF2 was observed to increase the expression of downstream Palladin proteins by activating the PI3K/Akt signaling pathway and also lead to the activation of epithelial-mesenchymal transition (EMT). Subsequently, EMT was found to promote the migration and invasion of pancreatic cancer cells. In summary, the HPA/SDC1 axis was revealed to serve an important role in the regulation of FGF2, and was found to promote the invasion and metastasis of pancreatic cancer cells. These findings indicated that the HPA/SDC1 axis may be used as an effective therapeutic target for pancreatic cancer.

Role of Heparanase in Macrophage Activation

Macrophages represent one of the most diverse immunocyte populations, constantly shifting between various phenotypes/functional states. In addition to execution of vital functions in normal physiological conditions, macrophages represent a key contributing factor in the pathogenesis of some of the most challenging diseases, such as chronic inflammatory disorders, diabetes and its complications, and cancer. Macrophage polarization studies focus primarily on cytokine-mediated mechanisms. However, to explore the full spectrum of macrophage action, additional, non-cytokine pathways responsible for altering macrophage phenotype have to be taken into consideration as well. Heparanase, the only known mammalian endoglycosidase that cleaves heparan sulfate glycosaminoglycans, has been shown to contribute to the altered macrophage phenotypes in vitro and in numerous animal models of inflammatory conditions, occurring either in the presence of microbial products or in the setting of non-infectious "aseptic" inflammation. Here we discuss the involvement of heparanase in shaping macrophage responses and provide information that may help to establish the rationale for heparanase-targeting interventions aimed at preventing abnormal macrophage activation in various disorders.

Regulation of Heparanase in Diabetes-Associated Pancreatic Carcinoma

While at least six types of cancer have been associated with diabetes, pancreatic ductal adenocarcinoma (PDAC) and diabetes exhibit a unique bidirectional relationship. Recent reports indicate that majority of PDAC patients display hyperglycemia, and ~50% have concurrent diabetes. In turn, hyperglycemic/diabetic state in PDAC patients fosters enhanced growth and dissemination of the tumor. Heparanase enzyme (the sole mammalian endoglycosidase degrading glycosaminoglycan heparan sulfate) is tightly implicated in PDAC progression, aggressiveness, and therapy resistance. Overexpression of heparanase is a characteristic feature of PDAC, correlating with poor prognosis. However, given the lack of heparanase expression in normal pancreatic tissue, the regulatory mechanisms responsible for induction of the enzyme in PDAC have remained largely unknown. Previously reported inducibility of heparanase gene by diabetic milieu components in several non-cancerous cell types prompted us to hypothesize that in the setting of diabetes-associated PDAC, hyperglycemic state may induce heparanase overexpression. Here, utilizing a mouse model of diet-induced metabolic syndrome/diabetes, we found accelerated PDAC progression in hyperglycemic mice, occurring along with induction of heparanase in PDAC. In vitro, we demonstrated that advanced glycation end-products (AGE), which are largely thought as oxidative derivatives resulting from chronic hyperglycemia, and the receptor for AGE (RAGE) are responsible for heparanase induction in PDAC cells. These findings underscore the new mechanism underlying preferential expression of heparanase in pancreatic cancer. Moreover, taken together with the well-established causal role of the enzyme in PDAC progression, our findings indicate that heparanase may sustain (at least in part) reciprocal causality between diabetes and pancreatic tumorigenesis.

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.

Prophylactic Antiheparanase Activity by PG545 Is Antiviral In Vitro and Protects against Ross River Virus Disease in Mice

Recently we reported on the efficacy of pentosan polysulfate (PPS), a heparan sulfate mimetic, to reduce the recruitment of inflammatory infiltrates and protect the cartilage matrix from degradation in Ross River virus (RRV)-infected PPS-treated mice. Here, we describe both prophylactic and therapeutic treatment with PG545, a low-molecular-weight heparan sulfate mimetic, for arthritogenic alphaviral infection. We first assessed antiviral activity in vitro through a 50% plaque reduction assay. Increasing concentrations of PG545 inhibited plaque formation prior to viral adsorption in viral strains RRV T48, Barmah Forest virus 2193, East/Central/South African chikungunya virus (CHIKV), and Asian CHIKV, suggesting a strong antiviral mode of action. The viral particle-compound dissociation constant was then evaluated through isothermal titration calorimetry. Furthermore, prophylactic RRV-infected PG545-treated mice had reduced viral titers in target organs corresponding to lower clinical scores of limb weakness and immune infiltrate recruitment. At peak disease, PG545-treated RRV-infected mice had lower concentrations of the matrix-degrading enzyme heparanase in conjunction with a protective effect on tissue morphology, as seen in the histopathology of skeletal muscle. Enzyme-linked immunosorbent assay quantification of cartilage oligomeric matrix protein and cross-linked C-telopeptides of type II collagen as well as knee histopathology showed increased matrix protein degradation and cartilage erosion in RRV-infected phosphate-buffered saline-treated mice compared to their PG545-treated RRV-infected counterparts. Taken together, these findings suggest that PG545 has a direct antiviral effect on arthritogenic alphaviral infection and curtails RRV-induced inflammatory disease when administered as a prophylaxis.

Heparanase expression in blood is sensitive to monitor response to anticancer treatment in pancreatic cancer, a pilot study

BACKGROUND

/Objectives: High heparanase level was shown in maliganant tumor; however, whether or not heparanase may serve as a sensitive marker to monitor response to anticancer treatment is still unknown.

METHODS

In the pilot study, heparanase mRNA expression in peripheral blood mononuclear cell fraction (PBMC) and activity in plasma and urine were detected by quantitative real time RT-PCR and heparan-degrading enzyme assay in 31 pancreatic cancer patients.

RESULTS

Heparanase mRNA and activity in samples from cancer patients were significantly higher than that in healthy donors. Both heparanase mRNA and activity in plasma and urine decreased significantly in 17 patients who underwent R₀ resection, but increased remarkably in 6 patients when recurrence or metastasis occurred (P < 0.05). However, those who underwent R₁ or R₂ resection in 6 patients kept stable. For 8 patients who received chemotherapy, heparanase mRNA and activity in plasma and urine decreased in each of the samples (P < 0.05). Patients with high heparanase mRNA (≥a cutoff value of 1.84) in PBMC and activity in plasma (≥1.30U/ml) were associated with a poor postoperative survival (P = 0.02 and P = 0.04).

CONCLUSIONS

Heparanase mRNA in PBMC and activity in plasma are closely correlated with therapeutic responsiveness and survival time, indicating that heparanase level in blood might be a sensitive but non-specific marker to monitor patients' response to anticancer treatment and to predict survival.

The pathogenic roles of heparan sulfate deficiency in hereditary multiple exostoses

Heparan sulfate (HS) is an essential component of cell surface and matrix proteoglycans (HS-PGs) that include syndecans and perlecan. Because of their unique structural features, the HS chains are able to specifically interact with signaling proteins -including bone morphogenetic proteins (BMPs)- via their HS-binding domain, regulating protein availability, distribution and action on target cells. Hereditary Multiple Exostoses (HME) is a rare pediatric disorder linked to germline heterozygous loss-of-function mutations in EXT1 or EXT2 that encode Golgi-resident glycosyltransferases responsible for HS synthesis, resulting in a systemic HS deficiency. HME is characterized by cartilaginous/bony tumors -called osteochondromas or exostoses- that form within perichondrium in long bones, ribs and other elements. This review examines most recent studies in HME, framing them in the context of classic studies. New findings show that the spectrum of EXT mutations is larger than previously realized and the clinical complications of HME extend beyond the skeleton. Osteochondroma development requires a somatic "second hit" that would complement the germline EXT mutation to further decrease HS production and/levels at perichondrial sites of osteochondroma induction. Cellular studies have shown that the steep decreases in local HS levels: derange the normal homeostatic signaling pathways keeping perichondrium mesenchymal; cause excessive BMP signaling; and provoke ectopic chondrogenesis and osteochondroma formation. Data from HME mouse models have revealed that systemic treatment with a BMP signaling antagonist markedly reduces osteochondroma formation. In sum, recent studies have provided major new insights into the molecular and cellular pathogenesis of HME and the roles played by HS deficiency. These new insights have led to the first ever proof-of-principle demonstration that osteochondroma formation is a druggable process, paving the way toward the creation of a clinically-relevant treatment.

3D-spheroids: What can they tell us about pancreatic ductal adenocarcinoma cell phenotype?

We aimed at analyzing the effect of the 3D-arrangement on the expression of some genes and proteins which play a key role in pancreatic adenocarcinoma (PDAC) progression in HPAF-II, HPAC and PL45 PDAC cells cultured in either 2D-monolayers or 3D-spheroids. Cytokeratins 7, 8, 18, 19 were differently expressed in 3D-spheroids compared to 2D-monolayers. Syndecan 1 was upregulated in HPAF-II and PL45 3D-spheroids, and downregulated in HPAC. Heparanase mRNA levels were almost unchanged in HPAF-II, and increased in HPAC and PL45 3D-spheroids. Hyaluronan synthase (HAS) 2 and 3 mRNA increased in all 3D-spheroids compared to 2D-monolayers. CD44 and CD44s were expressed to a lower extent in HPAF-II and HPAC 3D-spheroids. By contrast, the CD44s/v3 and the CD44s/v6 ratio increased in HPAC and PL45 3D-spheroids, compared to 2D-monolayers. The expression of MMP-7 was strongly upregulated in 3D-spheroids. STAT3 was similarly expressed 3D-spheroids or 2D-monolayers, while pSTAT3 was almost undetectable in 2D-monolayers and strongly upregulated in 3D-spheroids. These results suggest that 3D-spheroids represent a cell culture model that allows the characterization of PDAC cell phenotype, adding new information that contributes to a better understanding of the biology and behavior of PDAC cells.

Hereditary Multiple Exostoses: New Insights into Pathogenesis, Clinical Complications, and Potential Treatments

PURPOSE OF REVIEW

Hereditary multiple exostoses (HME) is a complex musculoskeletal pediatric disorder characterized by osteochondromas that form next to the growth plates of many skeletal elements, including long bones, ribs, and vertebrae. Due to its intricacies and unresolved issues, HME continues to pose major challenges to both clinicians and biomedical researchers. The purpose of this review is to describe and analyze recent advances in this field and point to possible targets and strategies for future biologically based therapeutic intervention.

RECENT FINDINGS

Most HME cases are linked to loss-of-function mutations in EXT1 or EXT2 that encode glycosyltransferases responsible for heparan sulfate (HS) synthesis, leading to HS deficiency. Recent genomic inquiries have extended those findings but have yet to provide a definitive genotype-phenotype correlation. Clinical studies emphasize that in addition to the well-known skeletal problems caused by osteochondromas, HME patients can experience, and suffer from, other symptoms and health complications such as chronic pain and nerve impingement. Laboratory work has produced novel insights into alterations in cellular and molecular mechanisms instigated by HS deficiency and subtending onset and growth of osteochondroma and how such changes could be targeted toward therapeutic ends. HME is a rare and orphan disease and, as such, is being studied only by a handful of clinical and basic investigators. Despite this limitation, significant advances have been made in the last few years, and the future bodes well for deciphering more thoroughly its pathogenesis and, in turn, identifying the most effective treatment for osteochondroma prevention.

Heparanase stimulates chondrogenesis and is up-regulated in human ectopic cartilage: a mechanism possibly involved in hereditary multiple exostoses

Hereditary multiple exostoses is a pediatric skeletal disorder characterized by benign cartilaginous tumors called exostoses that form next to growing skeletal elements. Hereditary multiple exostoses patients carry heterozygous mutations in the heparan sulfate (HS)-synthesizing enzymes EXT1 or EXT2, but studies suggest that EXT haploinsufficiency and ensuing partial HS deficiency are insufficient for exostosis formation. Searching for additional pathways, we analyzed presence and distribution of heparanase in human exostoses. Heparanase was readily detectable in most chondrocytes, particularly in cell clusters. In control growth plates from unaffected persons, however, heparanase was detectable only in hypertrophic zone. Treatment of mouse embryo limb mesenchymal micromass cultures with exogenous heparanase greatly stimulated chondrogenesis and bone morphogenetic protein signaling as revealed by Smad1/5/8 phosphorylation. It also stimulated cell migration and proliferation. Interfering with HS function both with the chemical antagonist Surfen or treatment with bacterial heparitinase up-regulated endogenous heparanase gene expression, suggesting a counterintuitive feedback mechanism that would result in further HS reduction and increased signaling. Thus, we tested a potent heparanase inhibitor (SST0001), which strongly inhibited chondrogenesis. Our data clearly indicate that heparanase is able to stimulate chondrogenesis, bone morphogenetic protein signaling, cell migration, and cell proliferation in chondrogenic cells. These properties may allow heparanase to play a role in exostosis genesis and pathogenesis, thus making it a conceivable therapeutic target in hereditary multiple exostoses.

Influence of Heparanase and VEGF-C mRNA Expressions in Lung Cancer

The objective of this study is to investigate relationship between the expressions of heparanase and vascular endothelial growth factor-C (VEGF-C) mRNA and tumorigenesis, progression in human lung cancer. The expressions of heparanase and VEGF-C mRNA in 65 cases of lung cancer (31 cases of squamous cell carcinoma, 25 adenocarcinoma, 3 large cell carcinoma, and 6 small cell carcinoma), adjacent tissues of cancer, and normal tissues were tested by reverse transcription-polymerase chain reaction (RT-PCR) and analyzed by clinico-pathological characteristics and prognosis of lung cancer. The rate of expressions of heparanase and VEGF-C mRNA in tumor tissues (55.4, 61.5 %) was significantly higher than that in adjacent tissues of cancer (12.3, 15.4 %) and normal tissues (3.1, 4.6 %) (P < 0.05). It was shown that heparanase and VEGF-C mRNA expressions did not correlate with the pathological type and grade of the tumor (P > 0.05), but they correlated with the clinical stage and survival time of the patients (P < 0.05). Overexpression of heparanase and VEGF-C mRNA in lung cancer tissues perhaps participates in regulation of tumorigenesis and progression. The expressions of heparanase and VEGF-C mRNA should be used as a useful marker of the biological behavior of lung cancer and as an independent prognosis factor for the patient's survival.

Macrophage polarization in pancreatic carcinoma: role of heparanase enzyme

BACKGROUND

Tumor microenvironment, and particularly tumor-associated macrophages (TAMs), represent a key contributing factor in pancreatic ductal adenocarcinoma (PDAC) pathogenesis. Here we report that heparanase (predominant enzyme degrading heparan sulfate, the main polysaccharide found at the cell surface and extracellular matrix) directs tumor-promoting behavior of TAM in PDAC.

METHODS

A mouse model of heparanase-overexpressing pancreatic carcinoma (n = 5 mice/group), tumor-associated macrophages ex vivo, primary wild-type and heparanase-null macrophages, and histological specimens from PDAC patients (n = 16), were analyzed, applying immunostaining, enzyme-linked immunosorbent assay, real-time reverse transcription-polymerase chain reaction, cell proliferation, and heparanase activity assays. All statistical tests are two-sided.

RESULTS

We found that overexpression of heparanase is associated with increased TAM infiltration in both experimental (P = .002) and human (P = .01) PDAC. Moreover, macrophages derived from heparanase-rich tumors (which grew faster in mouse hosts), display pronounced procancerous phenotype, evidenced by overexpression of MSR-2, IL-10, CCL2, VEGF, and increased production of IL-6, an important player in PDAC pathogenesis. Furthermore, in vitro heparanase enzyme-rendered macrophages (stimulated by necrotic cells which are often present in PDAC tissue) procancerous, as exemplified by their enhanced production of key cytokines implicated in PDAC (including IL-6), as well as by their ability to induce STAT3 signaling and to augment pancreatic carcinoma cell proliferation. In agreement, we observed activation of STAT3 in experimental and clinical specimens of heparanase-overexpressing PDAC.

CONCLUSIONS

Our findings underscore a novel function of heparanase in molecular decision-making that guides cancer-promoting action of TAM and imply that heparanase expression status may become highly relevant in defining a target patient subgroup that is likely to benefit the most from treatment modalities targeting TAM/IL-6/STAT3.

The Role of Heparanase and Sulfatases in the Modification of Heparan Sulfate Proteoglycans within the Tumor Microenvironment and Opportunities for Novel Cancer Therapeutics

Heparan sulfate proteoglycans (HSPGs) are an integral and dynamic part of normal tissue architecture at the cell surface and within the extracellular matrix. The modification of HSPGs in the tumor microenvironment is known to result not just in structural but also functional consequences, which significantly impact cancer progression. As substrates for the key enzymes sulfatases and heparanase, the modification of HSPGs is typically characterized by the degradation of heparan sulfate (HS) chains/sulfation patterns via the endo-6-O-sulfatases (Sulf1 and Sulf2) or by heparanase, an endo-glycosidase that cleaves the HS polymers releasing smaller fragments from HSPG complexes. Numerous studies have demonstrated how these enzymes actively influence cancer cell proliferation, signaling, invasion, and metastasis. The activity or expression of these enzymes has been reported to be modified in a variety of cancers. Such observations are consistent with the degradation of normal architecture and basement membranes, which are typically compromised in metastatic disease. Moreover, recent studies elucidating the requirements for these proteins in tumor initiation and progression exemplify their importance in the development and progression of cancer. Thus, as the influence of the tumor microenvironment in cancer progression becomes more apparent, the focus on targeting enzymes that degrade HSPGs highlights one approach to maintain normal tissue architecture, inhibit tumor progression, and block metastasis. This review discusses the role of these enzymes in the context of the tumor microenvironment and their promise as therapeutic targets for the treatment of cancer.

Overexpression of heparanase in ovarian cancer and its clinical significance

It has been reported that heparanase (HPSE) is overexpressed in ovarian cancer and is associated with tumor invasion and metastasis. However, a systematic study on the contribution of HPSE to tumor metastasis is rarely reported. In this study, based on the measurement of HPSE serum concentration, the expression of HPSE at both the mRNA and protein levels in tumors and its effects on the biological behaviors of cancer cells, we elucidated the role of HPSE in tumor invasion and metastasis in ovarian cancer and concluded that either the expression of HPSE in cancer and/or the serum concentration of HPSE may be a useful biomarker for the evaluation of surgery effects and prognosis prediction.

Heparanase-1 and components of the hedgehog signalling pathway are increased in untreated alveolar orbital rhabdomyosarcoma

BACKGROUND

To assess the activities of heparanase-1 and elements of the hedgehog signalling pathway in alveolar orbital rhabdomyosarcoma.

METHODS

Specimens (n = 23) were divided into two groups, those from patients with preoperative chemoradiotherapy or untreated patients; six samples of normal extraocular muscle were used as a normal muscle group. The presence of heparanase-1, patched, smoothened and glioma-associated oncogene homologue-1 protein expression was determined in 23 cases of archival paraffin-embedded alveolar orbital rhabdomyosarcoma after immunohistochemistry. RNA was extracted from three groups of paraffin-embedded specimens and messenger RNA expressions of heparanase-1, smoothened and glioma-associated oncogene homologue-1 compared using nested reverse transcriptase polymerase chain reaction and a limiting dilution analysis.

RESULTS

The heparanase-1, patched, smoothened and glioma-associated oncogene homologue-1 protein was expressed in 91.3%, 87.0%, 91.3% and 78.3%, respectively, of the alveolar orbital rhabdomyosarcoma specimens. Untreated rhabdomyosarcoma samples tended to stain intensely, but staining was relatively weak in tissue obtained from the chemoradiotherapy group. The expression levels of heparanase-1, smoothened and glioma-associated oncogene homologue-1 messenger RNA in untreated and chemoradiotherapy groups paralleled that seen with immunology, and there were no significant differences in heparanase-1, smoothened and glioma-associated oncogene homologue-1 messenger RNA levels between the chemoradiotherapy group and the normal muscle group (P > 0.05). However, the messenger RNA in the untreated group were all significantly higher than those in the chemoradiotherapy and normal muscle groups (P < 0.01).

CONCLUSIONS

Both heparanase-1 and hedgehog signalling pathway are involved in the pathogenesis of alveolar orbital rhabdomyosarcoma; however, chemotherapy and/or radiotherapy appears to significantly inhibit their upregulation.

PG545, an angiogenesis and heparanase inhibitor, reduces primary tumor growth and metastasis in experimental pancreatic cancer

Aggressive tumor progression, metastasis, and resistance to conventional therapies lead to an extremely poor prognosis for pancreatic ductal adenocarcinoma (PDAC). Heparanase, an enzyme expressed by multiple cell types, including tumor cells in the tumor microenvironment, has been implicated in angiogenesis and metastasis, and its expression correlates with decreased overall survival in PDAC. We evaluated the therapeutic potential of PG545, an angiogenesis and heparanase inhibitor, in experimental PDAC. PG545 inhibited the proliferation, migration, and colony formation of pancreatic cancer cells in vitro at pharmacologically relevant concentrations. Heparanase inhibition also reduced the proliferation of fibroblasts but had only modest effects on endothelial cells in vitro. Furthermore, PG545 significantly prolonged animal survival in intraperitoneal and genetic models (mPDAC: LSL-Kras(G12D); Cdkn2a(lox/lox); p48(Cre)) of PDAC. PG545 also inhibited primary tumor growth and metastasis in orthotopic and genetic endpoint studies. Analysis of tumor tissue revealed that PG545 significantly decreased cell proliferation, increased apoptosis, reduced microvessel density, disrupted vascular function, and elevated intratumoral hypoxia. Elevated hypoxia is a known driver of collagen deposition and tumor progression; however, tumors from PG545-treated animals displayed reduced collagen deposition and a greater degree of differentiation compared with control or gemcitabine-treated tumors. These results highlight the potent antitumor activity of PG545 and support the further exploration of heparanase inhibitors as a potential clinical strategy for the treatment of PDAC.

Cancer-associated lysosomal changes: friends or foes?

Rapidly dividing and invasive cancer cells are strongly dependent on effective lysosomal function. Accordingly, transformation and cancer progression are characterized by dramatic changes in lysosomal volume, composition and cellular distribution. Depending on one's point of view, the cancer-associated changes in the lysosomal compartment can be regarded as friends or foes. Most of them are clearly transforming as they promote invasive growth, angiogenesis and drug resistance. The same changes can, however, strongly sensitize cells to lysosomal membrane permeabilization and thereby to lysosome-targeting anti-cancer drugs. In this review we compile our current knowledge on cancer-associated changes in lysosomal composition and discuss the consequences of these alterations to cancer progression and the possibilities they can bring to cancer therapy.

Development of a biosensor for detection of pleural mesothelioma cancer biomarker using surface imprinting

Hyaluronan-linked protein 1 (HAPLN1) which has been shown to be highly expressed in malignant pleural mesotheliomas (MPM), was detected in serum using an electrochemical surface-imprinting method. First, the detection method was optimized using Bovine serum albumin (BSA) as a model protein to mimic the optimal conditions required to imprint the similar molecular weight protein HAPLN1. BSA was imprinted on the gold electrode with hydroxyl terminated alkane thiols, which formed a self-assembled monolayer (SAM) around BSA. The analyte (BSA) was then washed away and its imprint (empty cavity with shape-memory) was used for detection of BSA in a solution, using electrochemical open-circuit potential method, namely potentiometry. Factors considered to optimize the conditions include incubation time, protein concentration, limit of detection and size of electrode. Matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) was used to confirm selectivity of imprints. With the obtained imprinting control parameters, HAPLN1 was imprinted in duplicate and the detection of spiked HAPLN1 was successfully conducted in serum.

Heparanase is involved in the proliferation and invasion of nasopharyngeal carcinoma cells

Heparanase (HPSE), an endo-β-D-glucuronidase, is overexpressed in nasopharyngeal carcinoma (NPC). The purpose of our study was to investigate the possible role of HPSE in the development of NPC. RNA interference (RNAi) using an HPSE small hairpin RNA (HPSE shRNA) was used to identify the effects of HPSE on the regulation of the malignant behaviors of NPC. CNE-2, a highly metastatic human NPC cell line in which HPSE mRNA and protein levels were detected to be the highest in three NPC cell lines involved in the research, was selected as a cell model in vitro and in vivo. The results showed that downregulation of HPSE significantly inhibited the proliferative and invasive abilities of CNE-2 cells partially through MAPK signaling. Compared with the parental NPC cells, HPSE-silenced cells exhibited attenuated capacity for developing tumors in nude mice, while the growth of tumor xenografts derived from these cells was dramatically suppressed. In conclusion, our results suggest that HPSE contributes to the proliferation and metastasis of NPC, and HPSE may be a potent molecular target for NPC treatment.

The expression and clinical significance of microRNA-1258 and heparanase in human breast cancer

OBJECTIVES

To investigate the expression profile of miR-1258 and heparanase (HPSE) in breast cancer and to assess their clinicopathological significance.

DESIGN AND METHODS

The expression levels of miR-1258 and HPSE were analyzed in normal, benign and malignant breast tissues. Their serum levels were evaluated in healthy women and in patients with benign and malignant breast disease. We studied the correlation between the expression of miR-1258 and HPSE and the clinical features presented by the patients.

RESULTS

MiR-1258 was down-regulated and HPSE was up-regulated in breast cancer, with a significant inverse correlation. A reduced miR-1258 expression and an elevated HPSE expression were associated with the lymph node status, late clinical stages, a short overall survival and a short relapse-free survival. In frozen fresh tissue samples, the miR-1258 levels in breast cancer with lymph node metastasis were significantly lower than that of breast cancer without lymph node metastasis and benign disease (BD). In contrast, the HPSE levels in breast cancer with lymph node metastasis were the highest. In serum samples, the miR-1258 levels in metastatic breast cancer (M1) were lower than that of primary breast cancer (M0) and BD. However, serum HPSE levels of M1 patients were significantly higher than that of M0 patients and BD patients.

CONCLUSIONS

MiR-1258 may play an important role in breast cancer development and progression by regulating the expression of HPSE, and they might be potential prognostic biomarkers for breast cancer.

Significance of heparanase in cancer and inflammation

Heparan sulfate proteoglycans (HSPGs) are primary components at the interface between virtually every eukaryotic cell and its extracellular matrix. HSPGs not only provide a storage depot for heparin-binding molecules in the cell microenvironment, but also decisively regulate their accessibility, function and mode of action. As such, they are intimately involved in modulating cell invasion and signaling loops that are critical for tumor growth, inflammation and kidney function. In a series of studies performed since the cloning of the human heparanase gene, we and others have demonstrated that heparanase, the sole heparan sulfate degrading endoglycosidase, is causally involved in cancer progression, inflammation and diabetic nephropathy and hence is a valid target for drug development. Heparanase is causally involved in inflammation and accelerates colon tumorigenesis associated with inflammatory bowel disease. Notably, heparanase stimulates macrophage activation, while macrophages induce production and activation of latent heparanase contributed by the colon epithelium, together generating a vicious cycle that powers colitis and the associated tumorigenesis. Heparanase also plays a decisive role in the pathogenesis of diabetic nephropathy, degrading heparan sulfate in the glomerular basement membrane and ultimately leading to proteinuria and kidney dysfunction. Notably, clinically relevant doses of ionizing radiation (IR) upregulate heparanase expression and thereby augment the metastatic potential of pancreatic carcinoma. Thus, combining radiotherapy with heparanase inhibition is an effective strategy to prevent tumor resistance and dissemination in IR-treated pancreatic cancer patients. Also, accumulating evidence indicate that peptides derived from human heparanase elicit a potent anti-tumor immune response, suggesting that heparanase represents a promising target antigen for immunotherapeutic approaches against a broad variety of tumours. Oligosaccharide-based compounds that inhibit heparanase enzymatic activity were developed, aiming primarily at halting tumor growth, metastasis and angiogenesis. Some of these compounds are being evaluated in clinical trials, targeting both the tumor and tumor microenvironment.

Heparanase and cyclooxygenase-2 gene and protein expressions during progression of oral epithelial dysplasia to carcinoma

Heparanase and cyclooxygenase-2 (COX-2) are 2 key enzymes that modulate diverse physiological processes during embryonic development and in adult life. Their deregulations have been implicated in the growth and progression of many cancer types. To date, comparatively little is known about the roles of these molecules during oral carcinogenesis. The aim of this study was to investigate the expression patterns of heparanase and COX-2 during progression of oral epithelial dysplasia (OED) to carcinoma. In situ hybridization and immunohistochemistry were performed on 5 cases of normal mucosa, 15 cases of OED, 5 cases of carcinoma in situ and/or microinvasive carcinoma, and 40 cases of oral squamous cell carcinoma (OSCC). Results demonstrated that heparanase and COX-2 messenger RNA and protein were absent in normal oral mucosa but were coexpressed in increasing intensity as OED progressed to OSCC. Concomitant heparanase- and COX-2-positive staining in the stromal cells suggests that OED/OSCC progression may be modulated by stromal-cancer cell interactions. Diffuse intense staining of poorly differentiated OSCC compared with staining localized to tumor nest periphery in well- and moderately differentiated OSCC suggests that heparanase and COX-2 overexpressions correlated with tumor grade. Strong expression of these enzymes in tumor cells at the advancing front suggests a role in local tumor spread. These results, taken together, suggest that heparanase and COX-2 might play complementary roles in the stepwise progression of OED to carcinoma.

The expression of heparanase and microRNA-1258 in human non-small cell lung cancer

This study aims to discuss the correlation between miR-1258 and the expression of heparanase (HPSE) in the cancer cells of the patients with non-small cell lung cancer (NSCLC) and the inhibition mechanism of miR-1258 on the invasion of lung cancer cell. The expression level of miR-1258 was detected by TaqMan real-time PCR assay, the expression of HPSE was detected by immunohistochemistry, and the expression level of HPSE in the cancer tissue of each case was detected by western blot and in its adjacent tissue of 53 patients with NSCLC. The influence of miR-1258 on the invasion potential of the lung cancer cell line A549 was studied with lentivirus system including cloned miR-1258 fragments subsequently. The expression of HPSE and miR-1258 in NSCLC tissue was not obviously related to patient's gender, age, differentiation extent of cancer tissue, cancer types, etc., but also staging and lymph node metastasis, and the difference was significant. Further studies showed that the relationship between the expression level of miR-1258 and the expression of HPSE was closer. The relative expression level of miR-1258 was 0.58 ± 0.07 in HPSE positive sample and 1.58 ± 0.11 in HPSE negative sample, and the difference of which was notably significant (P < 0.0001). Western blot showed that the expression level of HPSE was highly negatively related to the expression level of miR-1258. The invasion potential of A549 was notably lowered when transfected by miR-1258. The miR-1258 regulates the expression level of HPSE to influence the morbidity and metastasis of NSCLC. The miR-1258 is likely to become the key to the treatment of lung cancer metastasis.

Heparanase expression in head and neck squamous cell carcinomas is associated with reduced proliferation and improved survival

AIMS

Cellular expression of heparanase, a degrading enzyme of the extracellular matrix, is associated with poorer prognosis in several cancers. The present analysis, has studied the role of heparanase in tumour growth and clinical outcome in patients with head and neck squamous cell carcinoma (HNSCC).

METHODS AND RESULTS

We analysed the cellular expression of the active form of heparanase in 71 human HNSCCs, using immunohistochemistry. The results were compared with clinicopathological data and, in 65 cases with immunoreactivity for the proliferation marker, MIB1. Cellular heparanase expression was detected in 41 of 71 (57.74%) cases; in particular, UICC IV-stage tumours showed high heparanase levels. Heparanase was localized mainly in the cytoplasm and, to a lesser extent, at the cell membrane. High levels of heparanase were significantly correlated with an almost four-fold decrease in MIB1 labelling (P = 0.006). Comparison with clinical outcome by multivariate analysis revealed that patients with high-level heparanase expression had prolonged overall survival (P = 0.029).

CONCLUSIONS

Although heparanase was mainly found in late-stage HNSCCs, cellular heparanase expression in HNSCCs was associated with prolonged overall survival. We propose that the proliferation-reducing effect of high heparanase levels might outweigh the tumour-promoting effects of heparanase, especially in advanced tumours.

Reactive oxygen species mediate high glucose-induced heparanase-1 production and heparan sulphate proteoglycan degradation in human and rat endothelial cells: a potential role in the pathogenesis of atherosclerosis

AIMS/HYPOTHESIS

The content of heparan sulphate is reduced in the endothelium under hyperglycaemic conditions and may contribute to the pathogenesis of atherosclerosis. Heparanase-1 (HPR1) specifically degrades heparan sulphate proteoglycans. We therefore sought to determine whether: (1) heparan sulphate reduction in endothelial cells is due to increased HPR1 production through increased reactive oxygen species (ROS) production; and (2) HPR1 production is increased in vivo in endothelial cells under hyperglycaemic and/or atherosclerotic conditions.

METHODS

HPR1 mRNA and protein levels in endothelial cells were analysed by RT-PCR and Western blot or HPR1 enzymatic activity assay, respectively. Cell surface heparan sulphate levels were analysed by FACS. HPR1 in the artery from control rats and a rat model of diabetes, and from patients under hyperglycaemic and/or atherosclerotic conditions was immunohistochemically examined.

RESULTS

High-glucose-induced HPR1 production and heparan sulphate degradation in three human endothelial cell lines, both of which were blocked by ROS scavengers, glutathione and N-acetylcysteine. Exogenous H(2)O(2) induced HPR1 production, subsequently leading to decreased cell surface heparan sulphate levels. HPR1 content was significantly increased in endothelial cells in the arterial walls of a rat model of diabetes. Clinical studies revealed that HPR1 production was increased in endothelial cells under hyperglycaemic conditions, and in endothelial cells and macrophages in atherosclerotic lesions.

CONCLUSIONS/INTERPRETATION

Hyperglycaemia induces HPR1 production and heparan sulphate degradation in endothelial cells through ROS. HPR1 production is increased in endothelial cells from a rat model of diabetes, and in macrophages in the atherosclerotic lesions of diabetic and non-diabetic patients. Increased HPR1 production may contribute to the pathogenesis and progression of atherosclerosis.

Role of heparanase in radiation-enhanced invasiveness of pancreatic carcinoma

Pancreatic cancer is characterized by very low survival rates because of high intrinsic resistance to conventional therapies. Ionizing radiation (IR)-enhanced tumor invasiveness is emerging as one mechanism responsible for the limited benefit of radiotherapy in pancreatic cancer. In this study, we establish the role of heparanase-the only known mammalian endoglycosidase that cleaves heparan sulfate-in modulating the response of pancreatic cancer to radiotherapy. We found that clinically relevant doses of IR augment the invasive capability of pancreatic carcinoma cells in vitro and in vivo by upregulating heparanase. Changes in the levels of the transcription factor Egr-1 occurred in pancreatic cancer cells following radiation, underlying the stimulatory effect of IR on heparanase expression. Importantly, the specific heparanase inhibitor SST0001 abolished IR-enhanced invasiveness of pancreatic carcinoma cells in vitro, whereas combined treatment with SST0001 and IR, but not IR alone, attenuated the spread of orthotopic pancreatic tumors in vivo. Taken together, our results suggest that combining radiotherapy with heparanase inhibition is an effective strategy to prevent tumor resistance and dissemination, observed in many IR-treated pancreatic cancer patients. Further, the molecular mechanism underlying heparanase upregulation in pancreatic cancer that we identified in response to IR may help identify patients in which radiotherapeutic intervention may confer increased risk of metastatic spread, where antiheparanase therapy may be particularly beneficial.

Induction of heparanase-1 expression by mutant B-Raf kinase: role of GA binding protein in heparanase-1 promoter activation

Heparanase-1 (HPR1), an endoglycosidase that specifically degrades heparan sulfate (HS) proteoglycans, is overexpressed in a variety of malignancies. Our present study sought to determine whether oncogene BRAF and RAS mutations lead to increased HPR1 expression. Reverse transcription-polymerase chain reaction analysis revealed that HPR1 gene expression was increased in HEK293 cells transiently transfected with a mutant BRAF or RAS gene. Flow cytometric analysis revealed that B-Raf activation led to loss of the cell surface HS, which could be blocked by two HPR1 inhibitors: heparin and PI-88. Cotransfection of a BRAF or RAS mutant gene with HPR1 promoter-driven luciferase reporters increased luciferase reporter gene expression in HEK293 cells. Knockdown of BRAF expression in a BRAF-mutated KAT-10 tumor cell line led to the suppression of HPR1 gene expression, subsequently leading to increased cell surface HS levels. Truncational and mutational analyses of the HPR1 promoter revealed that the Ets-relevant elements in the HPR1 promoter were critical for BRAF activation-induced HPR1 expression. Luciferase reporter gene expression driven by a four-copy GA binding protein (GABP) binding site was significantly lower in BRAF siRNA-transfected KAT-10 cells than in the control siRNA-transfected cells. We further showed that BRAF knockdown led to suppression of the expression of the GABPβ, an Ets family transcription factor involved in regulating HPR1 promoter activity. Taken together, our study suggests that B-Raf kinase activation plays an important role in regulating HPR1 expression. Increased HPR1 expression may contribute to the aggressive behavior of BRAF-mutated cancer.

Unraveling the specificity of heparanase utilizing synthetic substrates

Heparanase is a promising anticancer target because of its involvement in cancer invasion and metastasis. Heparanase cleaves heparan sulfate (HS), a sulfated polysaccharide, and activates a series of HS-mediated cell proliferation and angiogenesis processes. Understanding the substrate specificity of heparanase will aid the discovery of heparanase inhibitors. Here, we sought to determine the specificity of heparanase using synthetic polysaccharide substrates. The substrates were prepared using purified HS biosynthetic enzymes. Using these substrates, we were able to dissect the structural moieties required for heparanase. Our data suggest that heparanase cleaves the linkage between a GlcA unit and an N-sulfo glucosamine unit carrying either a 3-O-sulfo or a 6-O-sulfo group. In addition, heparanase cleaves the linkage of a GlcA unit and N-sulfo glucosamine unit with a 2-O-sulfated GlcA residue, not a 2-O-sulfated IdoA residue, in proximity. We also discovered that the polysaccharide with repeating disaccharide units of IdoA2S-GlcNS inhibits the activity of heparanase. Our findings advance the understanding of the substrate specificity of heparanase and identify a lead compound for developing polysaccharide-based heparanase inhibitors.

Heparanase activity in alveolar and embryonal rhabdomyosarcoma: implications for tumor invasion

Background

Rhabdomyosarcoma (RMS) is a malignant soft tissue sarcoma of childhood including two major histological subtypes, alveolar (ARMS) and embryonal (ERMS) RMS. Like other human malignancies RMS possesses high metastatic potential, more pronounced in ARMS than in ERMS. This feature is influenced by several biological molecules, including soluble factors secreted by tumor cells, such as heparanase (HPSE). HPSE is an endo-β-D-glucuronidase that cleaves heparan sulphate proteoglycans.

Methods

We determined HPSE expression by Western blot analysis in ARMS and ERMS cells lines and activity in supernatants by an ELISA assay. Stable HPSE silencing has been performed by shRNA technique in RH30 and RD cell lines and their invasiveness has been evaluated by Matrigel-invasion assay. HPSE activity and mRNA expression have also been quantified in plasma and biopsies from RMS patients.

Results

HPSE expression and activity have been detected in all RMS cell lines. Stable HPSE silencing by shRNA technique determined a significant knockdown of gene expression equal to 76% and 58% in RH30 and RD cell lines respectively and induced a less invasive behaviour compared to untreated cells. Finally, we observed that HPSE mRNA expression in biopsies was higher than in foetal skeletal muscle and that plasma from RMS patients displayed significantly more elevated HPSE levels than healthy subjects with a trend to higher levels in ARMS.

Conclusion

In conclusion, our data demonstrate for the first time HPSE expression and activity in RMS and highlight its involvement in tumor cell invasion as revealed by shRNA silencing. Moreover, HPSE expression in RMS patients is significantly higher with respect to healthy subjects. Further studies are warranted to assess possible relationships between HPSE and clinical behaviour in RMS.

High expression of heparanase is significantly associated with dedifferentiation and lymph node metastasis in patients with pancreatic ductal adenocarcinomas and correlated to PDGFA and via HIF1a to HB-EGF and bFGF

BACKGROUND

Pancreatic cancer still has one of the worst prognoses of all cancers with a 5-year survival rate of 5%, making it necessary to find markers or gene sets that would further classify patients into different risk categories and thus allow more individually adapted multimodality treatment regimens. Especially heparanase (HPSE) has recently been discussed as a key factor in pancreatic cancer.

MATERIALS AND METHODS

Paraffin-embedded tissue samples were obtained from 41 patients with pancreatic adenocarcinoma who were scheduled for primary surgical resection. Direct quantitative real-time reverse transcriptase polymerase chain reaction (TaqMan) assays were performed in triplicates to determine HPSE, hypoxia inducible factor-1 alpha (HIF1a), platelet-derived growth factor alpha (PDGFA), heparin-binding EGF-like growth factor (HB-EGF), and basic fibroblast growth factor (bFGF) gene expression levels.

RESULTS

HPSE was significantly correlated to PDGFA (p = 0.04) and HIF1a (p = 0.04). The correlation of HIF1a to bFGF and HB-EGF was significant (p = 0.04, p = 0.02). Stepwise multiple linear regression models showed a significant independent association of HPSE with lymph node metastasis (p = 0.025) and with dedifferentiation (p = 0.042).

CONCLUSIONS

Heparanase seems to be significantly associated with lymph node metastasis (p = 0.025) as well as dedifferentiation (p = 0.042). We assume that HPSE plays a crucial role for the aggressiveness of pancreatic cancer. Larger studies including more patients seem to be warranted.

Function of heparanase in prostate tumorigenesis: potential for therapy

PURPOSE

Heparanase is the predominant enzyme that cleaves heparan sulfate, the main polysaccharide in the extracellular matrix. Whereas the role of heparanase in sustaining the pathology of human cancer is well documented, its association with prostate carcinoma remains uncertain. Our research was undertaken to elucidate the significance of heparanase in prostate tumorigenesis and bone metastasis.

EXPERIMENTAL DESIGN

We applied immunohistochemical analysis of tissue microarray, in vitro adhesion and invasion assays, as well as mouse models of intraosseous growth and spontaneous metastasis of prostate cancer, monitored by whole-body bioluminescent imaging. Electroporation-assisted administration of anti-heparanase small interfering RNA in vivo was applied as a therapeutic approach.

RESULTS

We report a highly statistically significant (P < 0.0001) prevalence of heparanase overexpression in prostate carcinomas versus noncancerous tissue, as well as strong correlation between tumor grade and the extent of heparanase expression. We observed >5-fold increase in the metastatic potential of PC-3 prostate carcinoma cells engineered to overexpress heparanase. Notably, overexpression of a secreted form of the enzyme also led to a dramatic increase in intraosseous prostate tumor growth. Local in vivo silencing of heparanase resulted in a 4-fold inhibition of prostate tumor growth, representing the first successful application of anticancer therapy based on heparanase small interfering RNA and validating the potential of heparanase as a target for prostate cancer treatment.

CONCLUSIONS

Heparanase directly contributes to prostate tumor growth in bone and its ability to metastasize to distant organs. Thus, anti-heparanase strategy may become an important modality in the treatment of prostate cancer patients, particularly those with bone metastases.

Mammalian heparanase: what is the message?

Heparan sulphate proteoglycans are ubiquitous macromolecules of cell surfaces and extracellular matrices. Numerous extracellular matrix proteins, growth factors, morphogens, cytokines, chemokines and coagulation factors are bound and regulated by heparan sulphate. Degradation of heparan sulphate thus potentially profoundly affects cell and tissue function. Although there is evidence that several heparan sulphate-degrading endoglucuronidases (heparanases) might exist, so far only one transcript encoding a functional heparanase has been identified: heparanase-1. In the first part of this review, we discuss the current knowledge about heparan sulphate proteoglycans and the functional importance of their versatile interactions. In the second part, we summarize recent findings that have contributed to the characterization of heparanase-1, focusing on the molecular properties, working mechanism, substrate specificity, expression pattern, cellular activation and localization of this enzyme. Additionally, we review data implicating heparanase-1 in several normal and pathological processes, focusing on tumour metastasis and angiogenesis, and on evidence for a potentially direct signalling function of the molecule. In that context, we also briefly discuss heparanase-2, an intriguing close homologue of heparanase-1, for which, so far, no heparan sulphate-degrading activity could be demonstrated.

Estradiol induces heparanase-1 expression and heparan sulphate proteoglycan degradation in human endometrium

BACKGROUND

This study seeks to determine whether estrogen is able to regulate the expression of heparanase-1 (HPR1) in human endometrium.

METHODS

HPR1 expression and heparan sulphate (HS) deposition in the endometrium collected in various menstrual phases were analysed by immunohistochemical and immunofluorescence staining, respectively. HPR1 expression in the endometrial cells unexposed or exposed to estradiol was analysed by using RT-PCR and luciferase reporter assay. HPR1 activity was analysed by using a novel enzyme-linked immunosorbent assay (ELISA). Cell surface HS levels were analysed by flow cytometry. Serum HPR1 activity in women receiving follicle-stimulating hormone (FSH) for IVF was measured by ELISA.

RESULTS

HPR1 expression was rarely detected in the endometrium in the early and mid-proliferative phases but was increased in the late proliferative phase and in the secretory phases. HPR1 expression was negatively associated with HS in the basement membrane (BM) of the endometrial glands. HPR1 gene expression, HPR1 promoter activity and HPR1 enzymatic activity were increased in the endometrial cells when exposed to 17beta-estradiol (E(2)), whereas cell surface HS levels showed a decrease which could be blocked by PI-88, an HPR1 inhibitor. Serum HPR1 levels were increased in women with moderately elevated blood estrogen levels after receiving FSH.

CONCLUSIONS

HPR1 is differentially expressed in the endometrium in different menstrual phases. Estrogen plays an important role in inducing HPR1 expression, subsequently leading to HS degradation on the endometrial cell surface and in the BM of the endometrium.

In vivo and in vitro degradation of heparan sulfate (HS) proteoglycans by HPR1 in pancreatic adenocarcinomas. Loss of cell surface HS suppresses fibroblast growth factor 2-mediated cell signaling and proliferation

Heparan sulfate proteoglycans (HSPGs) function as a co-receptor for heparin-binding growth factors, such as fibroblast growth factors (FGFs) and heparin-bound epidermal growth factor (HB-EGF). The HS side chain of HSPGs can be cleaved by HPR1 (heparanase-1), an endoglycosidase that is overexpressed in many types of malignancies. In the present study, we demonstrated that HPR1 expression in pancreatic adenocarcinomas inversely correlated with the presence of heparan sulfate (HS) in the basement membrane. In vitro cell culture study revealed that cell surface HS levels inversely correlated with HPR1 activity in five pancreatic cancer cell lysates and their conditioned media. Heparin and PI-88, two HPR1 inhibitors, were able to increase cell surface HS levels in PANC-1 cells in a dose-dependent manner. The ability of HPR1 to degrade cell surface HS was confirmed by showing that cell surface HS levels were increased in HT1080 cells stably transfected with the HPR1 antisense gene but was decreased in the cells overexpressing HPR1. Further studies showed that PI-88 and heparin were able to stimulate PANC-1 cell proliferation in the absence or presence of exogenous FGF2, whereas exogenous HPR1 was able to inhibit PANC-1 cell proliferation in a dose-dependent manner. Modulation of PANC-1 cell proliferation by HPR1 or HPR1 inhibitors corresponded with the inhibition or activation of the mitogen-activated protein kinase. Our results suggest that HPR1 expressed in pancreatic adenocarcinomas can suppress the proliferation of pancreatic tumor cells in response to the growth factors that require HSPGs as their co-receptors.