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

Potential roles of heparanase in cancer therapy: Current trends and future direction

Heparanase (HPSE; heparanase-1) is an endo-β-glucuronidase capable of degrading the carbohydrate moiety of heparan sulfate proteoglycans, thus modulating and facilitating the remodeling of the extracellular matrix and basement membrane. HPSE activity is strongly associated with major human pathological complications, including but not limited to tumor progress and angiogenesis. Several lines of literature have shown that overexpression of HPSE leads to enhanced tumor growth and metastatic transmission, as well as poor prognosis. Gene silencing of HPSE or treatment of tumor with compounds that block HPSE activity are shown to remarkably attenuate tumor progression. Therefore, targeting HPSE is considered as a potential therapeutical strategy for the treatment of cancer. Intriguingly, recent findings disclose that heparanase-2 (HPSE-2), a close homolog of HPSE but lacking enzymatic activity, can also regulate antitumor mechanisms. Given the pleiotropic roles of HPSE, further investigation is in demand to determine the precise mechanism of regulating action of HPSE in different cancer settings. In this review, we first summarize the current understanding of HPSE, such as its structure, subcellular localization, and tissue distribution. Furthermore, we systematically review the pro- and antitumorigenic roles and mechanisms of HPSE in cancer progress. In addition, we delineate HPSE inhibitors that have entered clinical trials and their therapeutic potential.

Targeting syndecan-1: new opportunities in cancer therapy

Syndecan-1 (SDC1, CD138) is one of the heparan sulfate proteoglycans and is essential for maintaining normal cell morphology, interacting with the extracellular and intracellular protein repertoire, as well as mediating signaling transduction upon environmental stimuli. The critical role of SDC1 in promoting tumorigenesis and metastasis has been increasingly recognized in various cancer types, implying a promising potential of utilizing SDC1 as a novel target for cancer therapy. This review summarizes the current knowledge on SDC1 structure and functions, including its role in tumor biology. We also discuss the highlights and limitations of current SDC1-targeted therapies as well as the obstacles in developing new therapeutic methods, offering our perspective on the future directions to target SDC1 for cancer treatment.

Pancreatic Cancer and Platelets Crosstalk: A Potential Biomarker and Target

Platelets have been recognized as key players in hemostasis, thrombosis, and cancer. Preclinical and clinical researches evidenced that tumorigenesis and metastasis can be promoted by platelets through a wide variety of crosstalk between cancer cells and platelets. Pancreatic cancer is a devastating disease with high morbidity and mortality worldwide. Although the relationship between pancreatic cancer and platelets in clinical diagnosis is described, the interplay between pancreatic cancer and platelets, the underlying pathological mechanism and pathways remain a matter of intensive study. This review summaries recent researches in connections between platelets and pancreatic cancer. The existing data showed different underlying mechanisms were involved in their complex crosstalk. Typically, pancreatic tumor accelerates platelet aggregation which forms thrombosis. Furthermore, extracellular vesicles released by platelets promote communication in a neoplastic microenvironment and illustrate how these interactions drive disease progression. We also discuss the advantages of novel model organoids in pancreatic cancer research. A more in-depth understanding of tumor and platelets crosstalk which is based on organoids and translational therapies may provide potential diagnostic and therapeutic strategies for pancreatic cancer progression.

A Marine λ-Oligocarrageenan Inhibits Migratory and Invasive Ability of MDA-MB-231 Human Breast Cancer Cells through Actions on Heparanase Metabolism and MMP-14/MMP-2 Axis

Sugar-based molecules such as heparins or natural heparan sulfate polysaccharides have been developed and widely studied for controlling heparanase (HPSE) enzymatic activity, a key player in extracellular matrix remodelling during cancer pathogenesis. However, non-enzymatic functions of HPSE have also been described in tumour mechanisms. Given their versatile properties, we hypothesized that sugar-based inhibitors may interfere with enzymatic but also non-enzymatic HPSE activities. In this work, we assessed the effects of an original marine λ-carrageenan derived oligosaccharide (λ-CO) we previously described, along with those of its native counterpart and heparins, on cell viability, proliferation, migration, and invasion of MDA-MB-231 breast cancer cells but also of sh-MDA-MB-231 cells, in which the expression of HPSE was selectively downregulated. We observed no cytotoxic and no anti-proliferative effects of our compounds but surprisingly λ-CO was the most efficient to reduce cell migration and invasion compared with heparins, and in a HPSE-dependent manner. We provided evidence that λ-CO tightly controlled a HPSE/MMP-14/MMP-2 axis, leading to reduced MMP-2 activity. Altogether, this study highlights λ-CO as a potent HPSE “modulator” capable of reducing not only the enzymatic activity of HPSE but also the functions controlled by the HPSE levels.

Syndecans and Pancreatic Ductal Adenocarcinoma

Pancreatic Ductal Adenocarcinoma (PDAC) is a fatal disease with poor prognosis because patients rarely express symptoms in initial stages, which prevents early detection and diagnosis. Syndecans, a subfamily of proteoglycans, are involved in many physiological processes including cell proliferation, adhesion, and migration. Syndecans are physiologically found in many cell types and their interactions with other macromolecules enhance many pathways. In particular, extracellular matrix components, growth factors, and integrins collect the majority of syndecans associations acting as biochemical, physical, and mechanical transducers. Syndecans are transmembrane glycoproteins, but occasionally their extracellular domain can be released from the cell surface by the action of matrix metalloproteinases, converting them into soluble molecules that are capable of binding distant molecules such as extracellular matrix (ECM) components, growth factor receptors, and integrins from other cells. In this review, we explore the role of syndecans in tumorigenesis as well as their potential as therapeutic targets. Finally, this work reviews the contribution of syndecan-1 and syndecan-2 in PDAC progression and illustrates its potential to be targeted in future treatments for this devastating disease.

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.

Immunomodulatory activities of pixatimod: emerging nonclinical and clinical data, and its potential utility in combination with PD-1 inhibitors

BACKGROUND

Pixatimod (PG545) is a novel clinical-stage immunomodulatory agent capable of inhibiting the infiltration of tumor-associated macrophages (TAMs) yet also stimulate dendritic cells (DCs), leading to activation of natural killer (NK) cells. Preclinically, pixatimod inhibits heparanase (HPSE) which may be associated with its inhibitory effect on TAMs whereas its immunostimulatory activity on DCs is through the MyD88-dependent TLR9 pathway. Pixatimod recently completed a Phase Ia monotherapy trial in advanced cancer patients.

METHODS

To characterize the safety of pixatimod administered by intravenous (IV) infusion, a one month toxicology study was conducted to support a Phase Ia monotherapy clinical trial. The relative exposure (AUC) of pixatimod across relevant species was determined and the influence of route of administration on the immunomodulatory activity was also evaluated. Finally, the potential utility of pixatimod in combination with PD-1 inhibition was also investigated using the syngeneic 4T1.2 breast cancer model.

RESULTS

The nonclinical safety profile revealed that the main toxicities associated with pixatimod are elevated cholesterol, triglycerides, APTT, decreased platelets and other changes symptomatic of modulating the immune system such as pyrexia, changes in WBC subsets, inflammatory changes in liver, spleen and kidney. Though adverse events such as fever, elevated cholesterol and triglycerides were reported in the Phase Ia trial, none were considered dose limiting toxicities and the compound was well tolerated up to 100 mg via IV infusion. Exposure (AUC) up to 100 mg was considered proportional with some accumulation upon repeated dosing, a phenomenon also noted in the toxicology study. The immunomodulatory activity of pixatimod was independent of the route of administration and it enhanced the effectiveness of PD-1 inhibition in a poorly immunogenic tumor model.

CONCLUSIONS

Pixatimod modulates innate immune cells but also enhances T cell infiltration in combination with anti-PD-1 therapy. The safety and PK profile of the compound supports its ongoing development in a Phase Ib study for advanced cancer/pancreatic adenocarcinoma with the checkpoint inhibitor nivolumab (Opdivo®).

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02042781 . First posted: 23 January, 2014 - Retrospectively registered.

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.

Gemcitabine-induced heparanase promotes aggressiveness of pancreatic cancer cells via activating EGFR signaling

Pancreatic cancer (PC), characterized by aggressive local invasion and metastasis, is one of the most malignant cancers. Gemcitabine is currently used as the standard drug for the treatment of advanced and metastatic PC, but with limited efficacy. In this study, we demonstrated that gemcitabine increased the expression of heparanase (HPA1), the only known mammalian endoglycosidase capable of cleaving heparan sulfate, both in vitro and in vivo. Furthermore, overexpression of HPA1 in PC cell lines enhanced proliferation and invasion, accompanied with elevated phosphorylation of EGFR. In addition, we showed that the NF-κB pathway mediated the gemcitabine-induced HPA1 expression. Importantly, we found that an HPA1 inhibitor attenuated gemcitabine-induced invasion of PC cells. Finally, we showed that HPA1 was of negative prognostic value for PC patients. Taken together, our results demonstrated that gemcitabine-induced HPA1 promotes proliferation and invasion of PC cells through activating EGFR, implying that HPA1 may serve as promising therapeutic target in the treatment of PC.

Arctigenin, a lignan from Arctium lappa L., inhibits metastasis of human breast cancer cells through the downregulation of MMP-2/-9 and heparanase in MDA-MB-231 cells

Arctigenin is a bioactive lignan isolated from the seeds of Arctium lappa L. which has been widely used as a diuretic and a diaphoretic in Traditional Chinese Medicine. In the present study, the authors investigated the effects of arctigenin on tumor migration and invasion in aggressive human breast cancer cells. The MTT assay results showed that arctigenin did not show a significant cytotoxic effect on the cell viability of MDA-MB-231 cells. However, wound healing migration and Boyden chamber invasion assays demonstrated that arctigenin significantly inhibited in vitro migration and invasion of the MDA-MB-231 cells. Furthermore, gelatin zymography results showed that arctigenin reduced the activity of MMP-2 and MMP-9. Western blot analysis results demonstrated that the expression of MMP-2, MMP-9 and heparanase proteins was significantly downregulated following the treatment of arctigenin. Finally, the antiangiogenic activity of arctigenin was also examined by the chick embryo chorioallantoic membrane (CAM) assay. Arctigenin treatment significantly inhibited angiogenesis in the CAM. In conclusion, the results revealed that arctigenin significantly inhibited the migration and invasion of MDA-MB-231 cells by downregulating MMP-2, MMP-9 and heparanase expression. However, further studies are still necessary to investigate the exact mechanisms involved and to explore signal transduction pathways to better understand the biological mechanisms.

Heparanase: From basic research to therapeutic applications in cancer and inflammation

Heparanase, the sole heparan sulfate degrading endoglycosidase, regulates multiple biological activities that enhance tumor growth, angiogenesis and metastasis. Heparanase expression is enhanced in almost all cancers examined including various carcinomas, sarcomas and hematological malignancies. Numerous clinical association studies have consistently demonstrated that upregulation of heparanase expression correlates with increased tumor size, tumor angiogenesis, enhanced metastasis and poor prognosis. In contrast, knockdown of heparanase or treatments of tumor-bearing mice with heparanase-inhibiting compounds, markedly attenuate tumor progression further underscoring the potential of anti-heparanase therapy for multiple types of cancer. Heparanase neutralizing monoclonal antibodies block myeloma and lymphoma tumor growth and dissemination; this is attributable to a combined effect on the tumor cells and/or cells of the tumor microenvironment. In fact, much of the impact of heparanase on tumor progression is related to its function in mediating tumor-host crosstalk, priming the tumor microenvironment to better support tumor growth, metastasis and chemoresistance. The repertoire of the physio-pathological activities of heparanase is expanding. Specifically, heparanase regulates gene expression, activates cells of the innate immune system, promotes the formation of exosomes and autophagosomes, and stimulates signal transduction pathways via enzymatic and non-enzymatic activities. These effects dynamically impact multiple regulatory pathways that together drive inflammatory responses, tumor survival, growth, dissemination and drug resistance; but in the same time, may fulfill some normal functions associated, for example, with vesicular traffic, lysosomal-based secretion, stress response, and heparan sulfate turnover. Heparanase is upregulated in response to chemotherapy in cancer patients and the surviving cells acquire chemoresistance, attributed, at least in part, to autophagy. Consequently, heparanase inhibitors used in tandem with chemotherapeutic drugs overcome initial chemoresistance, providing a strong rationale for applying anti-heparanase therapy in combination with conventional anti-cancer drugs. Heparin-like compounds that inhibit heparanase activity are being evaluated in clinical trials for various types of cancer. Heparanase neutralizing monoclonal antibodies are being evaluated in pre-clinical studies, and heparanase-inhibiting small molecules are being developed based on the recently resolved crystal structure of the heparanase protein. Collectively, the emerging premise is that heparanase expressed by tumor cells, innate immune cells, activated endothelial cells as well as other cells of the tumor microenvironment is a master regulator of the aggressive phenotype of cancer, an important contributor to the poor outcome of cancer patients and a prime target for therapy.

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.

Heparanase inhibits osteoblastogenesis and shifts bone marrow progenitor cell fate in myeloma bone disease

A major cause of morbidity in patients with multiple myeloma is the development and progression of bone disease. Myeloma bone disease is characterized by rampant osteolysis in the presence of absent or diminished bone formation. Heparanase, an enzyme that acts both at the cell-surface and within the extracellular matrix to degrade polymeric heparan sulfate chains, is upregulated in a variety of human cancers including multiple myeloma. We and others have shown that heparanase enhances osteoclastogenesis and bone loss. However, increased osteolysis is only one element of the spectrum of myeloma bone disease. In the present study, we hypothesized that heparanase would also affect mesenchymal cells in the bone microenvironment and investigated the effect of heparanase on the differentiation of osteoblast/stromal lineage cells. Using a combination of molecular, biochemical, cellular and in vivo approaches, we demonstrated that heparanase significantly inhibited osteoblast differentiation and mineralization, and reduced bone formation in vivo. In addition, heparanase shifts the differentiation potential of osteoblast progenitors from osteoblastogenesis to adipogenesis. Mechanistically, this shift in cell fate is due, at least in part, to heparanase-enhanced production and secretion of the Wnt signaling pathway inhibitor DKK1 by both osteoblast progenitors and myeloma cells. Collectively, these data provide important new insights into the role of heparanase in all aspects of myeloma bone disease and strongly support the use of heparanase inhibitors in the treatment of multiple myeloma.

EGFR, FLT1 and heparanase as markers identifying patients at risk of short survival in cholangiocarcinoma

Background

Cholangiocarcinoma remains to be a tumor with very few treatment choices and limited prognosis. In this study, we sought to determine the prognostic role of fms-related tyrosine kinase 1/vascular endothelial growth factor receptor 1 (FLT1/VEGFR1), heparanase (HPSE) and epidermal growth factor receptor (EGFR) gene expression in patients with resected CCC.

Methods

47 formalin-fixed paraffin embedded FFPE tumor samples from patients with resected CCC were analyzed. FFPE tissues were dissected using laser-captured microdissection and analyzed for FLT1, FLT4, HPSE, Hif1a, VEGFA/C, HB-EGF, PDGFA, PDGF-RA and EGFR mRNA expression using a quantitative real-time RT-PCR method. Gene expression values (relative mRNA levels) are expressed as ratios between the target gene and internal reference genes (beta-actin, b2mg, rplp2, sdha).

Results

EGFR, FLT1 and HPSE expression levels were significantly associated with overall survival (OS). FLT1 showed the strongest significant independent association with overall survival in a multivariate cox regression analysis when compared to the other genes and clinicopathological factors with a nearly 5 times higher relative risk (4.74) of dying earlier when expressed in low levels (p = 0.04). ROC Curve Analysis revealed that measuring EGFR potentially identifies patients at risk of a worsened outcome with a sensitivity of 80% and a specificity of 75% (p = 0.01).

Conclusions

EGFR and FLT1 seem to be potential markers to identify those patients at high risk of dying from cholangiocarcinoma. Therefore these markers may help to identify patient subgroups in need for a more aggressive approach in a disease that is in desperate need for new approaches.

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.

Heparanase in inflammation and inflammation-associated cancer

Recent years have seen a growing body of evidence that enzymatic remodeling of heparan sulfate proteoglycans profoundly affects a variety of physiological and pathological processes, including inflammation, neovascularization, and tumor development. Heparanase is the sole mammalian endoglycosidase that cleaves heparan sulfate. Extensively studied in cancer progression and aggressiveness, heparanase was recently implicated in several inflammatory disorders as well. Although the precise mode of heparanase action in inflammatory reactions is still not completely understood, the fact that heparanase activity is mechanistically important both in malignancy and in inflammation argues that this enzyme is a candidate molecule linking inflammation and tumorigenesis in inflammation-associated cancers. Elucidation of the specific effects of heparanase in cancer development, particularly when inflammation is a causal factor, will accelerate the development of novel therapeutic/chemopreventive interventions and help to better define target patient populations in which heparanase-targeting therapies could be particularly beneficial.

Versatile role of heparanase in inflammation

Heparanase is the only known mammalian endoglycosidase capable of degrading heparan sulfate glycosaminoglycan, both in extracellular space and within the cells. It is tightly implicated in cancer progression and over the past few decades significant progress has been made in elucidating the multiple functions of heparanase in malignant tumor development, neovascularization and aggressive behavior. Notably, current data show that in addition to its well characterized role in cancer, heparanase activity may represent an important determinant in the pathogenesis of several inflammatory disorders, such as inflammatory lung injury, rheumatoid arthritis and chronic colitis. Nevertheless, the precise mode of heparanase action in inflammatory reactions remains largely unclear and recent observations suggest that heparanase can either facilitate or limit inflammatory responses, when tissue/cell-specific contextual cues may dictate an outcome of heparanase action in inflammation. In this review the involvement of heparanase in modulation of inflammatory reactions is discussed through a few illustrative examples, including neuroinflammation, sepsis-associated lung injury and inflammatory bowel disease. We also discuss possible action of the enzyme in coupling inflammation and tumorigenesis in the setting of inflammation-triggered 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.

Pancreatic endocrine neoplasms: a current update on genetics and imaging

Pancreatic endocrine neoplasms are rare pancreatic tumours that may occur sporadically or as part of inherited syndromes such as multiple endocrine neoplasia-1 syndrome, von Recklinghausen disease, von Hippel-Lindau syndrome and tuberous sclerosis complex. Recent advances in the genetics and pathology of hereditary syndromes have provided valuable insights into the pathophysiology and biology of sporadic pancreatic endocrine neoplasms. Evolving molecular data on the biology of these neoplasms have the potential for diagnostic, therapeutic and prognostic use.

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.

Heparanase enhances local and systemic osteolysis in multiple myeloma by upregulating the expression and secretion of RANKL

Excessive bone destruction is a major cause of morbidity in myeloma patients. However, the biological mechanisms involved in the pathogenesis of myeloma-induced bone disease are not fully understood. Heparanase, an enzyme that cleaves the heparan sulfate chains of proteoglycans, is upregulated in a variety of human tumors, including multiple myeloma. We previously showed that heparanase promotes robust myeloma tumor growth and supports spontaneous metastasis of tumor cells to bone. In the present study, we show, for the first time, that the expression of heparanase by myeloma tumor cells remarkably enhances bone destruction locally within the tumor microenvironment. In addition, enhanced heparanase expression in the primary tumor also stimulated systemic osteoclastogenesis and osteolysis, thus mimicking the systemic osteoporosis often seen in myeloma patients. These effects occur, at least in part, as the result of a significant elevation in the expression and secretion of receptor activator of NF-κB ligand (RANKL) by heparanase-expressing myeloma cells. Moreover, analysis of bone marrow biopsies from myeloma patients reveals a positive correlation between the level of expression of heparanase and RANKL. Together, these discoveries reveal a novel and key role for heparanase in promoting tumor osteolysis and show that RANKL is central to the mechanism of heparanase-mediated osteolysis in myeloma.

Clinicopathological significance of cell cycle regulatory factors and differentiation-related factors in pancreatic neoplasms

OBJECTIVES

The aim of the present study was to compare the expression levels of the cyclins and the differentiation-related factors in pancreatic neoplasms.

METHODS

The expression levels of cyclins A and B1, E1A-like inhibitor of differentiation 1 (EID-1), p300, 3'-5'-cyclic sdenosine monophosphate response element binding protein (CREB) binding protein (CBP), and acetylated histone H3 (AcH3) in ordinary ductal carcinoma (ODC) and intraductal papillary mucinous neoplasms (IPMNs) of the pancreas were investigated.

RESULTS

More cells positive for cyclin A and EID-1 were present in the ODC than in the IPMNs. Cells positive for both cyclins and EID-1 were observed more frequently in invasive carcinoma derived from the IPMN than from the IP mucinous carcinoma. Multivariate regression analysis revealed that EID-1 and cyclin A overexpressions were independent factors associated with poor prognosis. Overall survival was significantly lower in ODC patients with overexpressions of cyclin A, EID-1, and AcH3 than in those without such overexpressions. There were significant differences in the survival curves between patients with ODC and invasive carcinoma derived from IPMN, regarding high frequency for cyclin A or B1.

CONCLUSIONS

These results indicated that the expressions of cyclins A and B1, EID-1, and AcH3 may be correlated with a malignant potential in IPMNs. Invasive carcinoma derived from IPMN may be slow growing as compared with ODC.