Heparanase, a potential regulator of cell-matrix interactions

Unraveling neurovascular mysteries: the role of endothelial glycocalyx dysfunction in Alzheimer's disease pathogenesis

While cardiovascular disease, cancer, and human immunodeficiency virus (HIV) mortality rates have decreased over the past 20 years, Alzheimer's Disease (AD) deaths have risen by 145% since 2010. Despite significant research efforts, effective AD treatments remain elusive due to a poorly defined etiology and difficulty in targeting events that occur too downstream of disease onset. In hopes of elucidating alternative treatment pathways, now, AD is commonly being more broadly defined not only as a neurological disorder but also as a progression of a variety of cerebrovascular pathologies highlighted by the breakdown of the blood-brain barrier. The endothelial glycocalyx (GCX), which is an essential regulator of vascular physiology, plays a crucial role in the function of the neurovascular system, acting as an essential vascular mechanotransducer to facilitate ultimate blood-brain homeostasis. Shedding of the cerebrovascular GCX could be an early indication of neurovascular dysfunction and may subsequently progress neurodegenerative diseases like AD. Recent advances in in vitro modeling, gene/protein silencing, and imaging techniques offer new avenues of scrutinizing the GCX's effects on AD-related neurovascular pathology. Initial studies indicate GCX degradation in AD and other neurodegenerative diseases and have begun to demonstrate a possible link to GCX loss and cerebrovascular dysfunction. This review will scrutinize the GCX's contribution to known vascular etiologies of AD and propose future work aimed at continuing to uncover the relationship between GCX dysfunction and eventual AD-associated neurological deterioration.

The novel HS-mimetic, Tet-29, regulates immune cell trafficking across barriers of the CNS during inflammation

BACKGROUND

Disruption of the extracellular matrix at the blood-brain barrier (BBB) underpins neuroinflammation in multiple sclerosis (MS). The degradation of extracellular matrix components, such as heparan sulfate (HS) proteoglycans, can be prevented by treatment with HS-mimetics through their ability to inhibit the enzyme heparanase. The heparanase-inhibiting ability of our small dendrimer HS-mimetics has been investigated in various cancers but their efficacy in neuroinflammatory models has not been evaluated. This study investigates the use of a novel HS-mimetic, Tet-29, in an animal model of MS.

METHODS

Neuroinflammation was induced in mice by experimental autoimmune encephalomyelitis, a murine model of MS. In addition, the BBB and choroid plexus were modelled in vitro using transmigration assays, and migration of immune cells in vivo and in vitro was quantified by flow cytometry.

RESULTS

We found that Tet-29 significantly reduced lymphocyte accumulation in the central nervous system which, in turn, decreased disease severity in experimental autoimmune encephalomyelitis. The disease-modifying effect of Tet-29 was associated with a rescue of BBB integrity, as well as inhibition of activated lymphocyte migration across the BBB and choroid plexus in transwell models. In contrast, Tet-29 did not significantly impair in vivo or in vitro steady state-trafficking under homeostatic conditions.

CONCLUSIONS

Together these results suggest that Tet-29 modulates, rather than abolishes, trafficking across central nervous system barriers.

Accommodation in allogeneic and xenogeneic organ transplantation: Prevalence, impact, and implications for monitoring and for therapeutics

Accommodation refers to acquired resistance of organs or tissues to immune or inflammatory reactions that might otherwise cause severe injury or rejection. As first observed in ABO-incompatible kidney transplants and heterotopic cardiac xenografts, accommodation was identified when organ transplants continued to function despite the presence of anti-graft antibodies and/or other reactants in the blood of recipients. Recent evidence suggests many and perhaps most organ transplants have accommodation, as most recipients mount B cell responses specific for the graft. Wide interest in the impact of graft-specific antibodies on the outcomes of transplants prompts questions about which mechanisms confer protection against such antibodies, how accommodation might be detected and whether and how rejection could be superimposed on accommodation. Xenotransplantation offers a unique opportunity to address these questions because immune responses to xenografts are easily detected and the pathogenic impact of immune responses is so severe. Xenotransplantation also provides a compelling need to apply these and other insights to decrease the intensity and toxicity of immunosuppression that otherwise could limit clinical application.

Alterations of the Extracellular Matrix in Colorectal Carcinoma

Background: The process of proliferation and invasion of tumor cells depends on changes in the extracellular matrix (ECM) through the activation of enzymes and alterations in the profile of ECM components. Our aims are to investigate the mRNA and protein expression profiles of the ECM components, heparanase-1 (HPSE), heparanase-2 (HPSE2), matrix metalloproteinase-9 (MMP-9), and syndecan-1 (SDC1) in neoplastic and nonneoplastic tissues of 24 patients with colorectal carcinoma (CRC) and to test for associations between these expression patterns with the presence or absence of lymph node metastasis. Materials and Methods: This was a cross-sectional study in which 24 adult patients with CRC were admitted for resectional surgery. We analyzed the mRNA and protein expression patterns of the HPSE, HPSE2, MMP-9, and SDC1 genes by quantitative reverse transcription PCR and immunohistochemistry, respectively. Additionally, we investigated whether variations exist in the expression of the ECM components between the affected tissue and nontumoral tissue collected from the same patient. Tissue samples were collected immediately after the surgical resection. Results and Conclusion: The data showed higher mRNA and protein expression levels of HPSE2 (p = 0.0058), MMP-9 (p = 0.0268), and SDC1 (p = 0.0002) in tumor samples when compared with the nonneoplastic tissues. There was, however, only an increase in the level of the HPSE protein in the tumoral tissues. Increased expression of HPSE2 was observed in patients with lymph node metastasis (p = 0.031). This elevation in HPSE2 mRNA expression in patients with lymph node metastasis potentially indicates that it may participate in driving colorectal carcinoma progression.

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.

Enhanced anti-metastatic therapy with down-regulation of heparinase expression by ROS-responsive micellar nanoparticles

Metastasis is a major sign of malignant tumors which plays a vital role in cancer-related death. Suppressing metastasis is an important way to improve the survival rate of cancer patients. Herein, multifunctional PEG-LAM-PPS nanoparticles (nPLPs) are fabricated as both nanocarriers and anti-metastatic agents for tumor treatment. In this system, laminarin sulfate (LAM) suppresses metastasis by reducing heparinase and protecting the extracellular matrix; the ROS-sensitive polypropylene sulfide (PPS) improves the release of the loaded drug in the tumor microenvironment. This is the first time that laminarin sulfate has been used as a carrier to inhibit the expression of heparinase and treat melanoma lung metastasis. The blank nanoparticles are excellently safe and showed high anti-metastatic efficacy in melanoma lung metastatic mouse models, reducing metastatic nodules by 60%. They significantly improved the anti-tumor efficacy of the loaded drug doxorubicin, provided ∼33% further reduction of the tumor volume and 50% further reduction of the metastatic nodule number compared with free doxorubicin. Thus, these simple and versatile micellar nanoparticles composed of biocompatible materials offer a promising vehicle for treating invasive solid tumors and metastases.

The Heparan Sulfate Mimetic PG545 Modulates T Cell Responses and Prevents Delayed-Type Hypersensitivity

The heparan sulfate mimetic PG545 (pixatimod) is under evaluation as an inhibitor of angiogenesis and metastasis including in human clinical trials. We have examined the effects of PG545 on lymphocyte phenotypes and function. We report that PG545 treatment suppresses effector T cell activation and polarizes T cells away from Th17 and Th1 and toward Foxp3+ regulatory T cell subsets in vitro and in vivo. Mechanistically, PG545 inhibits Erk1/2 signaling, a pathway known to affect both T cell activation and subset polarization. Interestingly, these effects are also observed in heparanase-deficient T cells, indicating that PG545 has effects that are independent of its role in heparanase inhibition. Consistent with these findings, administration of PG545 in a Th1/Th17-dependent mouse model of a delayed-type hypersensitivity led to reduced footpad inflammation, reduced Th17 memory cells, and an increase in FoxP3+ Treg proliferation. PG545 also promoted Foxp3+ Treg induction by human T cells. Finally, we examined the effects of other heparan sulfate mimetics PI-88 and PG562 on lymphocyte polarization and found that these likewise induced Foxp3+ Treg in vitro but did not reduce Th17 numbers or improve delayed-type hypersensitivity in this model. Together, these data indicate that PG545 is a potent inhibitor of Th1/Th17 effector functions and inducer of FoxP3+ Treg. These findings may inform the adaptation of PG545 for clinical applications including in inflammatory pathologies associated with type IV hypersensitivity responses.

A Robust, One-step FRET Assay for Human Heparanase

Heparanase, an endo-β-D-glucuronidase, cleaves cell surface and extracellular matrix heparan sulfate (HS) chains at distinct sites and plays important biological roles including modulation of cell growth and metastasis. Although a number of different types of heparanase assays have been reported to date, most are labor intensive, complex and/or expensive to carry out. We reasoned that a simpler heparanase assay could be developed using heparin labeled with Dabcyl and EDANS as donor and acceptor fluorophores so as to generate a FRET signal. Our results show that a more robust heparanase assay could be developed based on the principle studied herein and more homogeneous preparation of heparin. Yet, the assay in its current form could be used for routine screening of potential inhibitors in a high-throughput manner as well as for studying heparanase activity expressed in tumors as well as biological fluids like plasma.

Graft glycocalyx degradation in human liver transplantation

OBJECTIVE

Ischaemia/reperfusion-injury degrades endothelial glycocalyx. Graft glycocalyx degradation was studied in human liver transplantation.

METHODS

To assess changes within the graft, blood was drawn from portal and hepatic veins in addition to systemic samples in 10 patients. Plasma syndecan-1, heparan sulfate and chondroitin sulfate, were measured with enzyme-linked immunosorbent assay.

RESULTS

During reperfusion, syndecan-1 levels were higher in graft caval effluent [3118 (934-6141) ng/ml, P = 0.005] than in portal venous blood [101 (75-121) ng/ml], indicating syndecan-1 release from the graft. Concomitantly, heparan sulfate levels were lower in graft caval effluent [96 (32-129) ng/ml, P = 0.037] than in portal venous blood [112 (98-128) ng/ml], indicating heparan sulfate uptake within the graft. Chondroitin sulfate levels were equal in portal and hepatic venous blood. After reperfusion arterial syndecan-1 levels increased 17-fold (P < 0.001) and heparan sulfate decreased to a third (P < 0.001) towards the end of surgery.

CONCLUSION

Syndecan-1 washout from the liver indicates extensive glycocalyx degradation within the graft during reperfusion. Surprisingly, heparan sulfate was taken up by the graft during reperfusion. Corroborating previous experimental reports, this suggests that endogenous heparan sulfate might be utilized within the graft in the repair of damaged glycocalyx.

Venous Thromboembolism Is an Independent Predictor of Mortality Among Patients with Gastric Cancer

BACKGROUND

Venous thromboembolism (VTE) is an independent predictor of death among patients with cancer. Patients with gastric cancer (GC) are at higher risk for VTE when compared to other solid tumors, and if one considers its prevalence, GC may be responsible for one of the highest incidences of cancer-associated thrombosis. The impact of VTE on mortality is not well defined among patients with GC.

AIM

The aim of this study is to measure the impact of VTE as independent predictor of GC mortality.

METHODS

Chart review of patients with GC treated in the Department of Oncology at John Stroger Hospital between the years of 2010 and 2015. VTE events were objectively confirmed with imaging in all cases. Active GC was defined as biopsy-proven metastatic disease or on active chemotherapy. Along with cancer-specific data, we abstracted risk assessments tools, non-GC-specific, validated for VTE and mortality prediction cancer, including the Khorana score (KRS), platelet lymphocyte ratio (PLR), and neutrophil lymphocyte ratio (NLR). Continuous variables are expressed by the median as appropriate according to normality. Categorical variables are expressed as percentages. SPSS version 22 was used and chi-square, Mann-Whitney U, Kaplan-Meier curve, and Cox proportional hazard with forward modeling were applied.

RESULTS

We included 112 patients in the analysis. The patients were predominantly men (66%), 58-year-old, with adenocarcinoma (84%) and advanced disease (59%). The median follow-up was 21.3 months (IQR 8.9-42.4). Cumulative incidence of VTE at 1 year was 9%. The median time from diagnosis to VTE occurrence was 59 days (IQR 36 to 258). Patients with VTE had worse OS when compared to the non-VTE group (medians 11.87 vs 29.97 months, p = 0.02). Patients stratified as high risk by the PLR had worse OS (medians 22.6 vs 42.77 months, p = 0.02). There was no statistical difference in OS among patients stratified as high risk by the KRS (medians 23.7 vs 42.5, p = 0.16) and NLR (medians 24.1 vs 42.7 months, p = 0.21). In multivariate analysis, the independent predictors of mortality were VTE (hazard ratio (HR), 2.9; 95% CI, 1.4 to 6.6; p < 0.01), adenocarcinoma (HR, 3.1; 95% CI, 1.1 to 9.0; p = 0.03), advanced disease (HR, 2.8; 95% CI, 1.4 to 5.8; p < 0.01), and PLR (HR, 2.2; 95% CI, 1.3 to 3.8; p < 0.01).

CONCLUSION

VTE is associated with worse survival among patients with GC along with adenocarcinoma, advanced disease, and PLR. Moreover, these findings were independent of other cancer- and treatment-specific variables. Although potentially predictive in other cancer types, NLR and KRS were not associated with worse survival in this cohort.

Progress of malignant mesothelioma research in basic science: A review of the 14th international conference of the international mesothelioma interest group (iMig2018)

Here we summarize the most recent update of mesothelioma research in basic science presented at the 14^th iMig2018 international conference. The symposium of basic science track mainly focused on the drivers of mesothelioma initiation and progression, molecular pathogenesis, and perspectives on potential therapeutic approaches. This review covers several promising fields including strategies efficiently inhibiting YAP/TAZ functions or their critical downstream targets, heparanase inhibitors, RAN depletion, and MIF/CD74 inhibitors that may be developed as novel therapeutic approaches. In addition, targeting mesothelioma stem cells by depleting M2-polarized macrophages in tumor microenvironment or blocking Tnfsf18 (GITRL)-GITR signalling might be translated into therapeutic modalities in mesothelioma treatment.

Polymeric fluorescent heparin as one-step FRET substrate of human heparanase

Heparanase, an endo-β-D-glucuronidase, cleaves cell surface and extracellular matrix heparan sulfate (HS) chains and plays important roles in cellular growth and metastasis. Heparanase assays reported to-date are labor intensive, complex and/or expensive. A simpler assay is critically needed to understand the myriad roles of heparanase. We reasoned that fluorescent heparin could serve as an effective probe of heparanase levels. Following synthesis and screening, a heparin preparation labeled with DABCYL and EDANS was identified, which exhibited a characteristic increase in signal following cleavage by human heparanase. This work describes the synthesis of this heparin substrate, its kinetic and spectrofluorometric properties, optimization of the heparanase assay, use of the assay in inhibitor screening, and elucidation of the state of heparanase in different cell lines. Our FRET-based assay is much simpler and more robust than all assays reported in the literature as well as a commercially available kit.

Cancer and Thrombosis-New Insights

Cancer patients have a pro-thrombotic state attributed to the ability of cancer cells to activate the coagulation system and interact with hemostatic cells, thus tilting the balance between pro- and anticoagulants. Mechanisms underlying the coagulation system activation involve tumor cells, endothelial cells, platelets, and white blood cells. Anti-cancer therapies, including anti-angiogenic drugs, significantly increase the risk of thrombosis during treatment. Along with the role of coagulation proteins in the hemostatic system, these proteins also serve as growth factors to the tumor. Heparanase is a pro-angiogenic and pro-metastatic protein. Our previous studies have demonstrated that it enhances tissue factor (TF) activity and is present at high levels in tumor cells and patients' blood. Strategies to attenuate heparanase effects by heparin mimetics or peptides interrupting the TF-heparanase interaction are good candidates to attenuate tumor growth and thrombotic manifestations.

Plasma heparanase is associated with blood glucose levels but not urinary microalbumin excretion in type 2 diabetic nephropathy at the early stage

Aim: To explore the possible correlations between plasma heparanase and albuminuria, glucose and lipid metabolism in the type 2 diabetic nephropathy patients at the early stage.

Methods: One hundred and forty patients with type 2 diabetic nephropathy at early stage were recruited into the study. Plasma heparanase and the characterized advanced glycation end products (AGEs), carboxymethyllysine (CML) were measured by enzyme-linked immunosorbent assay.

Results: Plasma heparanase was positively associated with fasting blood glucose (R = 0.24, p = .01) while heparanase was not significantly correlated with the urinary microalbumin to creatinine ratio (urinary mAlb/Cr) (R = 0.05, p = .58) and CML (R = 0.16, p = .26). On stepwise linear regression analysis, fasting blood glucose was the main independent determinants of plasma heparanase concentration.

Conclusion: Plasma heparanase is not significantly associated with urinary mAlb/Cr while it is correlated positively with blood glucose levels in the early stage of diabetic nephropathy. Plasma heparnase might be regarded as a marker for vascular endothelial cells injury in diabetic patients.

Patient derived xenografts (PDX) predict an effective heparanase-based therapy for lung cancer

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 facilitating cell invasion and regulating the bioavailability of heparin-binding proteins. HS mimicking compounds that inhibit heparanase enzymatic activity were examined in numerous preclinical cancer models. While these studies utilized established tumor cell lines, the current study utilized, for the first time, patient-derived xenografts (PDX) which better resemble the behavior and drug responsiveness of a given cancer patient. We have previously shown that heparanase levels are substantially elevated in lung cancer, correlating with reduced patients survival. Applying patient-derived lung cancer xenografts and a potent inhibitor of heparanase enzymatic activity (PG545) we investigated the significance of heparanase in the pathogenesis of lung cancer. PG545 was highly effective in lung cancer PDX, inhibiting tumor growth in >85% of the cases. Importantly, we show that PG545 was highly effective in PDX that did not respond to conventional chemotherapy (cisplatin) and vice versa. Moreover, we show that spontaneous metastasis to lymph nodes is markedly inhibited by PG545 but not by cisplatin. These results reflect the variability among patients and strongly imply that PG545 can be applied for lung cancer therapy in a personalized manner where conventional chemotherapy fails, thus highlighting the potential benefits of developing anti-heparanase treatment modalities for oncology.

Heparanase Activates Antithrombin through the Binding to Its Heparin Binding Site

Heparanase is an endoglycosidase that participates in morphogenesis, tissue repair, heparan sulphates turnover and immune response processes. It is over-expressed in tumor cells favoring the metastasis as it penetrates the endothelial layer that lines blood vessels and facilitates the metastasis by degradation of heparan sulphate proteoglycans of the extracellular matrix. Heparanase may also affect the hemostatic system in a non-enzymatic manner, up-regulating the expression of tissue factor, which is the initiator of blood coagulation, and dissociating tissue factor pathway inhibitor on the cell surface membrane of endothelial and tumor cells, thus resulting in a procoagulant state. Trying to check the effect of heparanase on heparin, a highly sulphated glycosaminoglycan, when it activates antithrombin, our results demonstrated that heparanase, but not proheparanase, interacted directly with antithrombin in a non-covalent manner. This interaction resulted in the activation of antithrombin, which is the most important endogenous anticoagulant. This activation mainly accelerated FXa inhibition, supporting an allosteric activation effect. Heparanase bound to the heparin binding site of antithrombin as the activation of Pro41Leu, Arg47Cys, Lys114Ala and Lys125Alaantithrombin mutants was impaired when it was compared to wild type antithrombin. Intrinsic fluorescence analysis showed that heparanase induced an activating conformational change in antithrombin similar to that induced by heparin and with a KD of 18.81 pM. In conclusion, under physiological pH and low levels of tissue factor, heparanase may exert a non-enzymatic function interacting and activating the inhibitory function of antithrombin.

Heparanase 2 Attenuates Head and Neck Tumor Vascularity and Growth

The endoglycosidase heparanase specifically cleaves the heparan sulfate (HS) side chains on proteoglycans, an activity that has been implicated strongly in tumor metastasis and angiogenesis. Heparanase-2 (Hpa2) is a close homolog of heparanase that lacks intrinsic HS-degrading activity but retains the capacity to bind HS with high affinity. In head and neck cancer patients, Hpa2 expression was markedly elevated, correlating with prolonged time to disease recurrence and inversely correlating with tumor cell dissemination to regional lymph nodes, suggesting that Hpa2 functions as a tumor suppressor. The molecular mechanism associated with favorable prognosis following Hpa2 induction is unclear. Here we provide evidence that Hpa2 overexpression in head and neck cancer cells markedly reduces tumor growth. Restrained tumor growth was associated with a prominent decrease in tumor vascularity (blood and lymph vessels), likely due to reduced Id1 expression, a transcription factor highly implicated in VEGF-A and VEGF-C gene regulation. We also noted that tumors produced by Hpa2-overexpressing cells are abundantly decorated with stromal cells and collagen deposition, correlating with a marked increase in lysyl oxidase expression. Notably, heparanase enzymatic activity was unimpaired in cells overexpressing Hpa2, suggesting that reduced tumor growth is not caused by heparanase regulation. Moreover, growth of tumor xenografts by Hpa2-overexpressing cells was unaffected by administration of a mAb that targets the heparin-binding domain of Hpa2, implying that Hpa2 function does not rely on heparanase or heparan sulfate. Cancer Res; 76(9); 2791-801. ©2016 AACR.

Heparan sulfate mimetic PG545-mediated antilymphoma effects require TLR9-dependent NK cell activation

Heparan sulfate (HS) is an essential component of the extracellular matrix (ECM), which serves as a barrier to tumor invasion and metastasis. Heparanase promotes tumor growth by cleaving HS chains of proteoglycan and releasing HS-bound angiogenic growth factors and facilitates tumor invasion and metastasis by degrading the ECM. HS mimetics, such as PG545, have been developed as antitumor agents and are designed to suppress angiogenesis and metastasis by inhibiting heparanase and competing for the HS-binding domain of angiogenic growth factors. However, how PG545 exerts its antitumor effect remains incompletely defined. Here, using murine models of lymphoma, we determined that the antitumor effects of PG545 are critically dependent on NK cell activation and that NK cell activation by PG545 requires TLR9. We demonstrate that PG545 does not activate TLR9 directly but instead enhances TLR9 activation through the elevation of the TLR9 ligand CpG in DCs. Specifically, PG545 treatment resulted in CpG accumulation in the lysosomal compartment of DCs, leading to enhanced production of IL-12, which is essential for PG545-mediated NK cell activation. Overall, these results reveal that PG545 activates NK cells and that this activation is critical for the antitumor effect of PG545. Moreover, our findings may have important implications for improving NK cell-based antitumor therapies.

The Profile of Heparanase Expression Distinguishes Differentiated Thyroid Carcinoma from Benign Neoplasms

Introduction

The search for a specific marker that could help to distinguish between differentiated thyroid carcinoma and benign lesions remains elusive in clinical practice. Heparanase (HPSE) is an endo-beta-glucoronidase implicated in the process of tumor invasion, and the heparanase-2 (HPSE2) modulates HPSE activity. The aim of this study was to evaluate the role of heparanases in the development and differential diagnosis of follicular pattern thyroid lesions.

Methods

HPSE and HPSE2 expression by qRT-PCR, immunohistochemistry evaluation, western blot analysis and HPSE enzymatic activity were evaluated.

Results

The expression of heparanases by qRT-PCR showed an increase of HPSE2 in thyroid carcinoma (P = 0.001). HPSE activity was found to be higher in the malignant neoplasms than in the benign tumors (P<0.0001). On Western blot analysis, HPSE2 isoforms were detected only in malignant tumors. The immunohistochemical assay allowed us to establish a distinct pattern for malignant and benign tumors. Carcinomas showed a typical combination of positive labeling for neoplastic cells and negative immunostaining in colloid, when compared to benign tumors (P<0.0001). The proposed diagnostic test presents sensitivity and negative predictive value of around 100%, showing itself to be an accurate test for distinguishing between malignant and benign lesions.

Conclusions

This study shows, for the first time, a distinct profile of HPSE expression in thyroid carcinoma suggesting its role in carcinogenesis.

Analysis of heparanase isoforms and cathepsin B in the plasma of patients with gastrointestinal carcinomas: analytical cross-sectional study

CONTEXT AND OBJECTIVE

Heparanase-1 degrades heparan sulfate and has been correlated with tumor progression. Although the isoform heparanase-2 has no catalytic activity, it seems to be important for modulating heparanase-1 activity. Cathepsin B is a proteinase involved in tumor metastasis. The aim of this study was to analyze heparanase isoform expression and cathepsin B activity in plasma samples from patients with gastrointestinal carcinomas, compared with healthy individuals (control group).

DESIGN AND SETTING

This was an analytical cross-sectional study. Peripheral blood samples were collected at a Brazilian public hospital, from 21 patients with histopathological diagnoses of gastrointestinal carcinomas and from 43 healthy individuals. The analyses were performed in two Brazilian medical schools.

METHODS

Heparanase isoforms were identified and quantified in plasma samples by means of Western blot. The enzymatic activities of heparanase-1 and cathepsin B were also measured.

RESULTS

The results demonstrated that the expression of both heparanase isoforms was significantly greater in plasma samples from gastrointestinal carcinoma patients, compared with the control group. Logistic regression analysis showed that increased heparanase-1 and heparanase-2 expression was exclusively dependent on the tumor. There was a significant increase in heparanase-1 and cathepsin B activity in the patients' plasma.

CONCLUSION

Overexpression of heparanase-1 and heparanase-2, along with increased heparanase-1 and cathepsin B activity in plasma, is associated with the diagnosis of gastrointestinal carcinoma. These findings provide support for using non-invasive assays (plasma samples) as an auxiliary method for diagnosing gastrointestinal tumors.

Processing of heparanase is mediated by syndecan-1 cytoplasmic domain and involves syntenin and α-actinin

Heparanase activity plays a decisive role in cell dissemination associated with cancer metastasis. Cellular uptake of heparanase is considered a pre-requisite for the delivery of latent 65-kDa heparanase to lysosomes and its subsequent proteolytic processing and activation into 8- and 50-kDa protein subunits by cathepsin L. Heparan sulfate proteoglycans, and particularly syndecan, are instrumental for heparanase uptake and activation, through a process that has been shown to occur independent of rafts. Nevertheless, the molecular mechanism underlying syndecan-mediated internalization outside of rafts is unclear. Here, we examined the role of syndecan-1 cytoplasmic domain in heparanase processing, utilizing deletion constructs lacking the entire cytoplasmic domain (Delta), the conserved (C1 or C2), or variable (V) regions. Heparanase processing was markedly increased following syndecan-1 over-expression; in contrast, heparanase was retained at the cell membrane and its processing was impaired in cells over-expressing syndecan-1 deleted for the entire cytoplasmic tail. We have next revealed that conserved domain 2 (C2) and variable (V) regions of syndecan-1 cytoplasmic tail mediate heparanase processing. Furthermore, we found that syntenin, known to interact with syndecan C2 domain, and α actinin are essential for heparanase processing.

Heparanase and coagulation-new insights

Heparanase, a β-D-endoglucuronidase abundant in platelets that was discovered 30 years ago, is an enzyme that cleaves heparan sulfate side chains on the cell surface and in the extracellular matrix. It was later recognized as being a pro-inflammatory and pro-metastatic protein. We had earlier demonstrated that heparanase may also affect the hemostatic system in a non-enzymatic manner. We had shown that heparanase up-regulated the expression of the blood coagulation initiator tissue factor (TF) and interacted with the tissue factor pathway inhibitor (TFPI) on the cell surface membrane of endothelial and tumor cells, leading to dissociation of TFPI and resulting in increased cell surface coagulation activity. Moreover, we have demonstrated that heparanase directly enhanced TF activity which led to increased factor Xa production and subsequent activation of the coagulation system. Recently, heparanase inhibitory peptides derived of TFPI-2 were demonstrated by us to inhibit heparanase procoagulant activity and attenuate sepsis in mouse models.

The mechanisms and physiological relevance of glycocalyx degradation in hepatic ischemia/reperfusion injury

SIGNIFICANCE

Hepatic ischemia/reperfusion (I/R) injury is an inevitable side effect of major liver surgery that can culminate in liver failure. The bulk of I/R-induced liver injury results from an overproduction of reactive oxygen and nitrogen species (ROS/RNS), which inflict both parenchymal and microcirculatory damage. A structure that is particularly prone to oxidative attack and modification is the glycocalyx (GCX), a meshwork of proteoglycans and glycosaminoglycans (GAGs) that covers the lumenal endothelial surface and safeguards microvascular homeostasis. ROS/RNS-mediated degradation of the GCX may exacerbate I/R injury by, for example, inducing vasoconstriction, facilitating leukocyte adherence, and directly activating innate immune cells.

RECENT ADVANCES

Preliminary experiments revealed that hepatic sinusoids contain a functional GCX that is damaged during murine hepatic I/R and major liver surgery in patients. There are three ROS that mediate GCX degradation: hydroxyl radicals, carbonate radical anions, and hypochlorous acid (HOCl). HOCl converts GAGs in the GCX to GAG chloramides that become site-specific targets for oxidizing and reducing species and are more efficiently fragmented than the parent molecules. In addition to ROS/RNS, the GAG-degrading enzyme heparanase acts at the endothelial surface to shed the GCX.

CRITICAL ISSUES

The GCX seems to be degraded during major liver surgery, but the underlying cause remains ill-defined.

FUTURE DIRECTIONS

The relative contribution of the different ROS and RNS intermediates to GCX degradation in vivo, the immunogenic potential of the shed GCX fragments, and the role of heparanase in liver I/R injury all warrant further investigation.

Alterations of plasma glycosaminoglycan profile in patients with rheumatoid arthritis in relation to disease activity

BACKGROUND

Qualitative and quantitative evaluation of plasma glycosaminoglycans (GAGs) of rheumatoid arthritis (RA) patients in relation to disease activity estimated by DAS28 score was evaluated.

METHODS

GAGs were quantified by hexuronic acid assay and electrophoretic fractionation. Keratan sulfate (KS) and hyaluronic acid (HA) were measured by immunoassay.

RESULTS

Chondroitin/dermatan sulfate (CS/DS) and heparan sulfate/heparin (HS/H) in plasma of healthy subjects and RA patients were stated. Total GAGs, CS, HS/H and HA levels were higher in patients with high and moderate disease activity than in controls. Total GAGs and CS levels in patients with high disease activity were elevated in comparison to patients with low disease activity. HS/H levels in patients with high and moderate activity were elevated in comparison to those with low disease activity. KS levels were increased in all patient groups in comparison to controls. Total GAGs, CS, HS/H and HA levels were positively correlated with DAS28 and CRP.

CONCLUSIONS

Structural tissue damage/remodeling of the extracellular matrix occurs in RA, which is reflected in the qualitative and quantitative changes of plasma GAGs. The above changes depend on DAS28 and may contribute to systemic changes in the properties of the extracellular matrix.

Dialysis-related transcriptomic profiling: the pivotal role of heparanase

Peritoneal (PD) and hemodialysis (HD) represent the leading renal replacement therapies in advanced chronic kidney disease (CKD). Although absolutely necessary to ensure patient survival, these treatments are responsible for considerable biological alterations primarily due to the un-physiological contact of blood and tissues with bioincompatible devices or plastificants. Although extensively described, this complex dialysis-related deregulated bio-molecular machinery is still not completely known. Therefore, to select a set of genes deregulated in patients on dialysis treatment and to assess the possible differences between dialysis modalities, we measured the expression level of 132 genes involved in proteoglycans (PGs) biosynthesis/metabolism by microarray in peripheral blood mononuclear cells (PBMCs), biological elements involved in the inflammatory/immune response, from 5 healthy subjects (HS), 9 CKD, 10 PD, and 17 HD patients. We focused on PGs biosynthesis/metabolism pathways because of their involvement in the onset and development of several CKD-related clinical complications. Statistical analysis/bioinformatics identified 70 genes discriminating HD/PD patients from HS/CKD subjects (P < 0.009, FDR < 5%). Twenty-five genes were up-regulated (e.g. HPSE, VCAN, and VEGFA) and 45 down-regulated (e.g. IDS and HEXA) in PD/HD compared to HS/CKD. Gene expression and plasma activity of Heparanase (HPSE), one of the top selected up-regulated genes in PD/HD, validated microarray results. In addition, for the second part of the study, HPSE plasmatic activities were first assessed in an independent testing-group (7 HS, 10 CKD, 17 PD, and 11 HD), and then correlated with high-sensitive C reactive protein (HS-CRP) measurements. HPSE activity was higher in PD and HD versus CKD/HS and it correlated with HS-CRP levels (R (2 )= 0.37, P = 0.007). Lipopolysaccharide (LPS)-stimulated PBMCs showed a significant up-regulation of HPSE mRNA level (P = 0.04). Our results revealed that dialysis treatments induce change in the transcriptomic pattern of biosynthetic proteoglycans in PBMCs with an up-regulation of HPSE. Our selected genes could be useful in the future as potential biomarkers and new therapeutic targets.

PG545, a heparan sulfate mimetic, reduces heparanase expression in vivo, blocks spontaneous metastases and enhances overall survival in the 4T1 breast carcinoma model

PG545 is a clinically relevant heparan sulfate (HS) mimetic which, in addition to possessing anti-angiogenic properties, also acts as a heparanase inhibitor which may differentiate its mechanism(s) of action from approved angiogenesis inhibitors. The degradation of HS by heparanase has been strongly implicated in cell dissemination and the metastatic process. Thus, the anti-metastatic activity of PG545 has been linked to the enzymatic function of heparanase - the only endoglycosidase known to cleave HS, an important component of the extracellular matrix (ECM) which represents a potential avenue for therapeutic intervention for certain metastatic cancer indications. Recent concerns raised about the paucity of overall survival as an endpoint in mouse models of clinically relevant metastasis led us to examine the effect of PG545 on the progression of both primary tumor growth and the spontaneously metastasizing disease in the 4T1 syngeneic breast carcinoma model in a non-surgical and surgical (mastectomy) setting. PG545 significantly inhibited primary tumor growth but importantly also inhibited lung metastasis in treated mice, an effect not observed with the tyrosine kinase inhibitor sorafenib. Importantly, PG545 significantly enhanced overall survival compared to vehicle control and the sorafenib group, suggesting PG545's inhibitory effect on heparanase is indeed a critical attribute to induce anti-metastatic activity. In addition to blocking a common angiogenic signalling pathway in tumor cells, the expression of heparanase in the primary tumor and lung was also significantly reduced by PG545 treatment. These results support the ongoing development of PG545 and highlight the potential utility in metastatic disease settings.

Clinical significance of heparanase splice variant (t5) in renal cell carcinoma: evaluation by a novel t5-specific monoclonal antibody

T5 is a novel splice variant of heparanase, an endo-β-D-glucuronidase capable of cleaving heparan sulfate side chains at a limited number of sites. T5 splice variant is endowed with pro-tumorigenic properties, enhancing cell proliferation, anchorage independent growth and tumor xenograft development despite lack of heparan sulfate-degrading activity typical of heparanase. T5 is over expressed in the majority of human renal cell carcinoma biopsies examined, suggesting that this splice variant is clinically relevant. T5 is thought to assume a distinct three-dimensional conformation compared with the wild type heparanase protein. We sought to exploit this presumed feature by generating monoclonal antibodies that will recognize the unique structure of T5 without, or with minimal recognition of heparanase, thus enabling more accurate assessment of the clinical relevance of T5. We provide evidence that such a monoclonal antibody, 9c9, preferentially recognizes T5 compared with heparanase by ELISA, immunoblotting and immunohistochemistry. In order to uncover the clinical significance of T5, a cohort of renal cell carcinoma specimens was subjected to immunostaining applying the 9c9 antibody. Notably, T5 staining intensity was significantly associated with tumor size (p = 0.004) and tumor grade (p = 0.02). Our results suggest that T5 is a functional, pro-tumorigenic entity.

Heparanase procoagulant activity

Heparanase that was cloned from and is abundant in the placenta is implicated in cell invasion, tumor metastasis and angiogenesis. We have recently demonstrated that heparanase may also affect the hemostatic system in a non-enzymatic manner. Heparanase was shown to up-regulate tissue factor (TF) expression and interact with tissue factor pathway inhibitor (TFPI) on cell surface, leading to dissociation of TFPI from cell membrane of endothelial and tumor cells, resulting in increased cell surface coagulation activity. We have lately shown that heparanase directly enhances TF activity resulting in increased factor Xa production and activation of the coagulation system. Data indicate increased plasma levels of heparanase suggesting its possible involvement in pregnancy vascular complications. Elevation in heparanase levels and procoagulant activity was also documented in orthopedic surgery patients receiving prophylactic doses of enoxaparin. Taking into account the pro-metastatic and pro-angiogenic functions of heparanase, with over-expression in human malignancies and abundance in platelets and placenta, its involvement in the coagulation machinery is an intriguing novel platform for further research.

Allele loss and down-regulation of heparanase gene are associated with the progression and poor prognosis of hepatocellular carcinoma

Objectives

The role of heparanase (HPSE) gene in cancers including hepatocellular carcinoma (HCC) is currently controversial. This study was aimed at investigating the impact of genetic alteration and expression change of HPSE on the progression and prognosis of HCC.

Methods

The HPSE gene was studied in three different aspects: (1) loss of heterozygosity (LOH) by a custom SNP microarray and DNA copy number by real-time PCR; (2) mRNA level by qRT-PCR; and (3) protein expression by immunohistochemistry. The clinical significances of allele loss and expression change of HPSE were analyzed.

Results

Microarray analysis showed that the average LOH frequency for 10 SNPs located within HPSE gene was 31.6%, three of which were significantly correlated with tumor grade, serum HBV-DNA level, and AFP concentration. In agreement with SNP LOH data, DNA copy number loss of HPSE was observed in 38.74% (43/111) of HCC cases. HPSE mRNA level was notably reduced in 74.1% (83/112) of tumor tissues compared with non-tumor liver tissues, which was significantly associated with DNA copy number loss, increased tumor size, and post-operative metastasis. HPSE protein level was also remarkably reduced in 66.3% (53/80) of tumor tissues, which was correlated with tumor grade. Patients with lower expression level of HPSE mRNA or protein had a significantly lower survival rate than those with higher expression. Cox regression analysis suggested that HPSE protein was an independent predictor of overall survival in HCC patients.

Conclusions

The results in this study demonstrate that genetic alteration and reduction of HPSE expression are associated with tumor progression and poor prognosis of HCCs, suggesting that HPSE behaves like a tumor suppressor gene and is a potential prognostic marker for HCC patients.

A Phylogenetic analysis of Heparanase (HPSE) gene

The Current Study aimed to investigate the possible role of Heparanase protein (HPSE-1, [Entrez Pubmed ref|NP_001092010.1|, heparanase isoform 1 preproprotein [Homo sapiens]) in evolution by studying the phylogenetic relationship and divergence of HPSE-1 gene using computational methods. The Human HPSE protein sequences from various species were retrieved from GenBank database and were compared using sequence alignment. Multiple sequence alignment was done using Clustal-W with defaults and phylogenetic trees for the gene were built using neighbor-joining method as in BLAST 2.2.26+ version. A total of 112 BLAST hits were found for the heparanase query sequence and these hits showed putative conserved domain, Glyco_hydro_79n superfamily. We then narrowed down the search by manually deleting the proteins which were not HPSE-1. These sequences were then subjected to phylogenetic analyses using the PhyML and TreeDyn software. Our study indicated that HPSE-1 is a conserved protein in classes Mammalia, Aves, Amphibia, Actinopterygii and Insecta emphasizing its importance in the physiology of cell membranes. Occurrence of this gene in evolution with conserved sites strengthens the role of HPSE-1 gene and helps in better understanding the biochemical processes that may lead to cancer.

Pre-clinical and clinical significance of heparanase in Ewing's sarcoma

Heparanase is an endoglycosidase that specifically cleaves heparan sulphate side chains of heparan sulphate proteoglycans, activity that is strongly implicated in cell migration and invasion associated with tumour metastasis, angiogenesis and inflammation. Heparanase up-regulation was documented in an increasing number of human carcinomas, correlating with reduced post-operative survival rate and enhanced tumour angiogenesis. Expression and significance of heparanase in human sarcomas has not been so far reported. Here, we applied the Ewing's sarcoma cell line TC71 and demonstrated a potent inhibition of cell invasion in vitro and tumour xenograft growth in vivo upon treatment with a specific inhibitor of heparanase enzymatic activity (compound SST0001, non-anticoagulant N-acetylated, glycol split heparin). Next, we examined heparanase expression and cellular localization by immunostaining of a cohort of 69 patients diagnosed with Ewing's sarcoma. Heparanase staining was noted in all patients. Notably, heparanase staining intensity correlated with increased tumour size (P = 0.04) and with patients' age (P = 0.03), two prognostic factors associated with a worse outcome. Our study indicates that heparanase expression is induced in Ewing's sarcoma and associates with poor prognosis. Moreover, it encourages the inclusion of heparanase inhibitors (i.e. SST0001) in newly developed therapeutic modalities directed against Ewing's sarcoma and likely other malignancies.

Heparanase-A Link between Coagulation, Angiogenesis, and Cancer

Heparanase that was cloned from and is abundant in the placenta is implicated in cell invasion, tumor metastasis, and angiogenesis. Recently we have demonstrated that heparanase may also affect the hemostatic system in a non-enzymatic manner. Heparanase was shown to up-regulate tissue factor (TF) expression and interact with tissue factor pathway inhibitor (TFPI) on the cell surface, leading to dissociation of TFPI from the cell membrane of endothelial and tumor cells, resulting in increased cell surface coagulation activity. More recently, we have shown that heparanase directly enhances TF activity, resulting in increased factor Xa production and activation of the coagulation system. Data indicate increased levels and possible involvement of heparanase in vascular complications in pregnancy. Taking into account the prometastatic and proangiogenic functions of heparanase, overexpression in human malignancies, and abundance in platelets and placenta, its involvement in the coagulation machinery is an intriguing novel arena for further research.

Heparanase induces signal transducer and activator of transcription (STAT) protein phosphorylation: preclinical and clinical significance in head and neck cancer

Activity of heparanase is implicated strongly in dissemination of metastatic tumor cells and cells of the immune system. In addition, heparanase enhances the phosphorylation of selected signaling molecules, including SRC and EGFR, in a manner that requires secretion but not enzymatic activity of heparanase and is mediated by its C-terminal domain. Clinically, heparanase staining is associated with larger tumors and increased EGFR phosphorylation in head and neck carcinoma. We hypothesized that signal transducer and activator of transcription (STAT) proteins mediate the protumorigenic function of heparanase downstream of the EGFR. We provide evidence that heparanase enhances the phosphorylation of STAT3 and STAT5b but not STAT5a. Moreover, enhanced proliferation of heparanase transfected cells was attenuated by STAT3 and STAT5b siRNA, but not STAT5a or STAT1 siRNA. Clinically, STAT3 phosphorylation was associated with head and neck cancer progression, EGFR phosphorylation, and heparanase expression and cellular localization. Notably, cytoplasmic rather than nuclear phospho-STAT3 correlated with increased tumor size (T-stage; p = 0.007), number of metastatic neck lymph nodes (p = 0.05), and reduced survival of patients (p = 0.04).

Evaluation of heparanase and matrix metalloproteinase-9 in patients with cutaneous malignant melanoma

Elevated heparanase and matrix metalloproteinase (MMP)-9, frequently found in human cancer, is a major cause of degradation of the extracellular matrix (ECM) and basement membrane (BM), thus facilitating tumor cell migration and invasion. Although a lot of work has been done, the role of heparanase and MMP-9 has not been delineated in skin cancer progression. The purpose of this study was to do such an exploration. To investigate the role of heparanase and MMP-9 in cutaneous malignant melanoma (CMM) development, we performed immunohistochemical analysis to detect the alternation of these two factors in paraffin-embedded biopsy specimens of normal skin, junctional nevi and CMM. It is interesting to note that the expression profile of heparanase and MMP-9 was similar. Contrary to negative staining in normal skin, overexpression of heparanase and cytoplasmic MMP-9 was observed in as many as 70% of CMM, whereas only 10% of the junctional nevi exhibited faint staining (P = 0.0005, P = 0.0000). Considering the lymph node (LN) metastasis, the expression of the two factors is significantly higher in LN-positive lesions than that in LN-negative lesions (P = 0.0295, P = 0.0013). Meanwhile, there was positive correlation between the expression of MMP-9 and heparanase (r = 0.689, P = 0.003). The first expression of MMP-9 and heparanase occurs at benign lesions. However, the significantly increased expression in advanced CMM stages, particularly in LN-positive metastasis lesions, might synergistically contribute to degradation of ECM and BM, therefore promoting carcinogenesis and metastasis.

Heparanase expression in periapical granulomas and radicular cysts

Heparanase is an endo-β-D-glucuronidase enzyme which degrades heparan sulfate glycosaminoglycan side chains of proteoglycans in the extracellular matrix and in basement membranes. The aim of this study was to evaluate the expression of heparanase in periapical granulomas (PGs) and radicular cysts (RCs). Immunohistochemistry was used to assess heparanase expression in PGs and RCs. Parameters including stain intensity, location and cell type were used to characterize heparanase expression in the periapical lesions. Ordered categories (from weak to strong) were used to compare the level of heparanase staining in the PG and RC groups. Both epithelial cells and inflammatory cells were positive for heparanase. The relative staining of the epithelial cells was strong, whereas the relative staining of the inflammatory cells was weak. Significant differences in immunohistochemical staining of epithelial cells were observed between RCs and PGs (p = 0.002). The relative expression of heparanase in epithelial cells in RCs was strong. In PGs, lesions with few or no epithelial cells, heparanase was predominantly expressed weakly by inflammatory cells. PGs and RCs have the same infectious origin. Therefore, the different cellular sources of heparanase in these periapical lesions may imply that this enzyme has specific pathogenetic functions in RCs and PGs.

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.

Heparanase modulation of early growth response gene expression

Heparan sulfate (HS), a polysaccharide ubiquitously expressed in animals, is essential for development and homeostasis. Degradation of HS by heparanase, an endoglucuronidase, may affect pathophysiological function. Expression of the heparanase gene has been found elevated in a number of pathological conditions. The goal of this work was to investigate the impact of heparanase on expression of other genes. DNA microarray analysis revealed that 1, 042 genes in the cortex and 1,039 genes in the thalamus are up- or down-regulated more than 2-fold in mouse brain overexpresssing human heparanase. Of these genes, two of the early growth response genes, Egr1 and Egr2, are substantially upregulated in the cortex, but essentially unchanged in the thalamus. RT-PCR analysis demonstrated a significant increase of Egr2, but a minor increase of Egr1, in human embryonic kidney cells stably overexpressing heparanase. The upregulated expression of Egr genes is also observed in hepatoma cells with upregulated expression of heparanase. Earlier studies reported that Egr1 induced heparanase expression; our findings suggest a possible reciprocal regulation of Egr and heparanase expression. Furthermore, overexpression of heparanase influenced expression of most genes involved in heparan sulfate proteoglycan biosynthesis, albeit to a different degree in the cortex and thalamus of the transgenic mice.

Heparanase: a universal immunotherapeutic target in human cancers

Heparanase has been identified as a particularly important player in metastasis, and its expression directly correlates with the metastatic spread of various tumors. Ideal targets for immunotherapy are gene products that are silenced in normal tissues but overexpressed in cancer, and that are directly involved in tumor cell survival and progression. Metastasis is the culmination of neoplastic progression. The importance of the role of heparanase in metastasis implies that immune escape by downregulation of heparanase expression could reduce the mortality of the cancer. These characteristics of heparanase make it an attractive universal target for cancer immunotherapy. Here, we review current knowledge about heparanase and its involvement in tumor metastasis, with an emphasis on recent results from heparanase-targeted cancer immunotherapy studies.

Heparanase levels are elevated in the urine and plasma of type 2 diabetes patients and associate with blood glucose levels

Heparanase is an endoglycosidase that specifically cleaves heparan sulfate side chains of heparan sulfate proteoglycans. Utilizing an ELISA method capable of detection and quantification of heparanase, we examined heparanase levels in the plasma and urine of a cohort of 29 patients diagnosed with type 2 diabetes mellitus (T2DM), 14 T2DM patients who underwent kidney transplantation, and 47 healthy volunteers. We provide evidence that heparanase levels in the urine of T2DM patients are markedly elevated compared to healthy controls (1162 ± 181 vs. 156 ± 29.6 pg/ml for T2DM and healthy controls, respectively), increase that is statistically highly significant (P<0.0001). Notably, heparanase levels were appreciably decreased in the urine of T2DM patients who underwent kidney transplantation, albeit remained still higher than healthy individuals (P<0.0001). Increased heparanase levels were also found in the plasma of T2DM patients. Importantly, urine heparanase was associated with elevated blood glucose levels, implying that glucose mediates heparanase upregulation and secretion into the urine and blood. Utilizing an in vitro system, we show that insulin stimulates heparanase secretion by kidney 293 cells, and even higher secretion is observed when insulin is added to cells maintained under high glucose conditions. These results provide evidence for a significant involvement of heparanase in diabetic complications.

IFN-beta pharmacogenomics in multiple sclerosis

Multiple sclerosis (MS) is a condition of the CNS marked by inflammation and neurodegeneration. Interferon (IFN)-beta was the first, and still is the main, immunomodulatory treatment for MS. Its clinical efficacy is limited, and a proportion of patients, ranging between 20-55%, do not respond to the therapy. Identification and subsequently, implementation in the clinic of biomarkers predictive for individual therapeutic response would facilitate improved patient care in addition to ensuring a more rational provision of this therapy. In this article, we summarize the main findings from studies addressing the pharmacogenomics of clinical response to IFN-beta in MS by either whole-genome association scans, candidate gene or transcriptomics studies. Whole-genome DNA association screens have revealed a high representation of brain-specific genes, and have hinted toward both extracellular ligand-gated ion channels and type I IFNs pathway genes as important categories of genetic IFN-beta response modifiers. One hit, glypican 5 (GPC5), was recently replicated in an independent study of IFN-beta responsiveness. Recent RNA transcriptomics studies have revealed the occurrence of a pre-existing type I IFN gene-expression signature, composed of genes that are predominantly induced by type I IFNs, as a potential contributing feature of poor response to therapy. Thus, while the outlines of a complex polygenic mechanism are gradually being uncovered, the main challenges for the near future will reside in the robust validation of identified response-modifying genes as well as in the decipherment of the mechanistic relationships between these genes and clinical response to IFN-beta.