Regulation, function and clinical significance of heparanase in cancer metastasis and angiogenesis

Endothelial cell dynamics in sepsis-induced acute lung injury and acute respiratory distress syndrome: pathogenesis and therapeutic implications

Sepsis, a prevalent critical condition in clinics, continues to be the leading cause of death from infections and a global healthcare issue. Among the organs susceptible to the harmful effects of sepsis, the lungs are notably the most frequently affected. Consequently, patients with sepsis are predisposed to developing acute lung injury (ALI), and in severe cases, acute respiratory distress syndrome (ARDS). Nevertheless, the precise mechanisms associated with the onset of ALI/ARDS remain elusive. In recent years, there has been a growing emphasis on the role of endothelial cells (ECs), a cell type integral to lung barrier function, and their interactions with various stromal cells in sepsis-induced ALI/ARDS. In this comprehensive review, we summarize the involvement of endothelial cells and their intricate interplay with immune cells and stromal cells, including pulmonary epithelial cells and fibroblasts, in the pathogenesis of sepsis-induced ALI/ARDS, with particular emphasis placed on discussing the several pivotal pathways implicated in this process. Furthermore, we discuss the potential therapeutic interventions for modulating the functions of endothelial cells, their interactions with immune cells and stromal cells, and relevant pathways associated with ALI/ARDS to present a potential therapeutic strategy for managing sepsis and sepsis-induced ALI/ARDS.

Chemical toolbox to interrogate Heparanase-1 activity

The development of a robust chemical toolbox to interrogate the activity of heparanase-1 (HPSE-1), an endo-β-d-glucuronidase and the only known enzyme that cleaves heparan sulfate (HS), has become critically important. The primary function of HPSE-1, cleaving HS side chains from heparan sulfate proteoglycans (HSPGs), regulates the integrity of the extracellular matrix (ECM) and the bioavailability of active, heparan sulfate-binding partners such as enzymes, growth factors, chemokines, and cytokines. HPSE-1 enzymatic activity is strictly regulated and has been found to play fundamental roles in pathophysiological processes. HPSE-1 is significantly overexpressed under various conditions including cancer, metastasis, angiogenesis, and inflammation, making HPSE-1 a promising therapeutic and diagnostic target. Chemical tools that can detect and image HPSE-1 activity in vitro and/or in vivo can help drive the discovery of novel and efficacious anti-HPSE-1 drugs, investigate the basic biology of HPSE-1, and help serve as a diagnostic tool in clinical applications. Here, we will give an overview of the common chemical tools to detect HPSE-1 activity and highlight the novel heparanase probes recently developed in our lab.

Heparanase interacting BCLAF1 to promote the development and drug resistance of ICC through the PERK/eIF2α pathway

Intrahepatic cholangiocarcinoma (ICC) is a primary epithelial carcinoma known for its aggressive nature, high metastatic potential, frequent recurrence, and poor prognosis. Heparanase (HPSE) is the only known endogenous β-glucuronidase in mammals. In addition to its well-established enzymatic roles, HPSE critically exerts non-catalytic function in tumor biology. This study herein aimed to investigate the non-enzymatic roles of HPSE as well as relevant regulatory mechanisms in ICC. Our results demonstrated that HPSE was highly expressed in ICC and promoted the proliferation of ICC cells, with elevated HPSE levels implicating a poor overall survival of ICC patients. Notably, HPSE interacted with Bcl-2-associated factor 1 (BCLAF1) to upregulate the expression of Bcl-2, which subsequently activated the PERK/eIF2α-mediated endoplasmic reticulum (ER) stress pathway to promote anti-apoptotic effect of ICC. Moreover, our in vivo experiments revealed that concomitant administration of gemcitabine and the Bcl-2 inhibitor navitoclax enhanced the sensitivity of ICC cells with highly expressed HPSE to chemotherapy. In summary, our findings revealed that HPSE promoted the development and drug resistance of ICC via its non-enzymatic function. Bcl-2 may be considered as an effective target with therapeutic potential to overcome ICC chemotherapy resistance induced by HPSE, presenting valuable insights into the development of novel therapeutic strategies against ICC.

Investigation of inhibitory effect of sulfated chitosan oligomer on human heparanase enzyme: in silico and in vitro studies

Deaths from cancer are widespread worldwide and the numbers continue to increase day by day. During the disease progression of cancer in cells, many of its metabolic activities change. Increased heparanase enzyme release is just one example. Following heparanase enzyme activity, many molecules interact with the remodeling of glycosaminoglycan structures, which triggers the release of different enzymes, cytokines, and growth factors, including fibroblast growth factors (FGF1 and FGF2), vascular endothelial growth factor (VEGF), hepatocyte growth factor, transforming growth factor β and platelet-derived growth factor. These are the most important factors in metastasis due to the formation of new vascular structures caused by those elements. To reduce tumor growth and metastasis, various drugs have been designed by modifying chitosan and its derivatives. In this study, we used chitosan oligomer (A), sulfated chitosan oligomer (ShCsO) (B), heparin (C), phosphate monomer (D1) of PI-88 and sulfate monomer (D2) of PI-88 as heparanase inhibitors. We modified the chitosan oligomer with chlorosulfonic acid to synthesize ShCsO to investigate its inhibitory effects on human serum heparanase. Also examined were molecular docking; molecular dynamics (MD); adsorption, distribution, metabolism, elimination and toxicity (ADMET); and target prediction. ShCsO decreased enzyme activity at a concentration of 0.0001 mg/mL. The docking scores of A, B and C from in silico studies were -6.254, -6.936 and -6.980 kcal/mol, respectively, and the scores for the two different PI-88 monomers were -5.741 and -5.824 kcal/mol. These results show that ShCsO may be a potential drug candidate for treating cancer.Communicated by Ramaswamy H. Sarma.

Discrepancy between recipient and donor rs4364254 heparanase single nucleotide polymorphism impacts graft-versus-host disease after allogeneic stem cell transplant

INTRODUCTION

The heparanase (HPSE) gene is highly polymorphic, but only a minority of its single nucleotide polymorphisms (SNPs) have been studied. Among these, rs4693608 and rs4364254 SNPs are closely associated with mRNA expression and HPSE protein levels in healthy subjects. Given the association between HPSE and inflammatory response, we aimed to evaluate whether HPSE rs4693608 and rs4364254 SNPs could have an impact on graft-versus-host disease after allogeneic stem cell transplants (HSCT).

METHODS

A total of 228 consecutive patients who underwent HSCT at our center between 2005 and 2018 were included. The rs4693608 SNP was identified by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis, while the rs4364254 was detected by allele-specific amplification.

RESULTS

The recipient-donor discrepancy for rs4364254 HPSE SNP was significantly associated with grade II-IV aGvHD (HR 1.75, p = 0.03). Patients were stratified into risk groups as follows: low-risk group (LDR) including TT-TT, TT-CT, CT-TT, CC-CC; high-risk group (HDR) including CC-CT, CC-TT, CT-CC, CT-CT, TT-CC. Day 100 cumulative incidence of grade II-IV aGvHD was 23.4% in the LDR group and 41.4% in the HDR group (p = 0.01). One-year cumulative incidence of moderate/severe cGvHD was 42.6% in the LDR group and 58.6% in the HDR group (p = 0.04). Independent variables for moderate/severe cGvHD in patients who received myeloablative conditioning included donor rs4693608 SNP (GA/AA vs. GG: HR 6.86, p = 0.008), rs4693608-rs4364254 SNP combination in recipient (HR/MR vs. LR: HR 3.67, p = 0.01), and previous grade II-IV aGvHD (HR 3.28, p = 0.0005). Finally, donors with rs4364254 SNP CC conferred increased transplant-related mortality (TRM) (39.1% vs. 25%, p = 0.03) and decreased graft-relapse free survival (GRFS) (23.5% vs. 34.4%, p = 0.04) compared with CT or TT genotypes.

CONCLUSION

The differences in incidence of GvHD according to recipient-donor genotype combinations suggests a possible role for rs4364254 HPSE SNP in predicting GvHD. A high level of HPSE, particularly linked to CC genotype of rs4364254 SNP may promote alloreactive T lymphocytes activation and migration toward target organs.

Synthetic Heparanase Inhibitors Can Prevent Herpes Simplex Viral Spread

Herpes simplex virus (HSV-1) employs heparan sulfate (HS) as receptor for cell attachment and entry. During late-stage infection, the virus induces the upregulation of human heparanase (Hpse) to remove cell surface HS allowing viral spread. We hypothesized that inhibition of Hpse will prevent viral release thereby representing a new therapeutic strategy for HSV-1. A range of HS-oligosaccharides was prepared to examine the importance of chain length and 2-O-sulfation of iduronic moieties for Hpse inhibition. It was found that hexa- and octasaccharides potently inhibited the enzyme and that 2-O-sulfation of iduronic acid is tolerated. Computational studies provided a rationale for the observed structure-activity relationship. Treatment of human corneal epithelial cells (HCEs) infected with HSV-1 with the hexa- and octasaccharide blocked viral induced shedding of HS which significantly reduced spread of virions. The compounds also inhibited migration and proliferation of immortalized HCEs thereby providing additional therapeutic properties.

Anti-Inflammatory and Anticancer Effects of Anticoagulant Therapy in Patients with Malignancy

Optimizing the anticoagulation therapy is of pivotal importance in patients with a malignant tumor, as venous thromboembolism (VTE) has become the second-leading cause of death in this population. Cancer can highly increase the risk of thrombosis and bleeding. Consequently, the management of cancer-associated VTE is complex. In recent years, translational research has intensified, and several studies have highlighted the role of inflammatory cytokines in cancer growth and progression. Simultaneously, the pleiotropic effects of anticoagulants currently recommended for VTE have emerged. In this review, we describe the anti-inflammatory and anticancer effects of both direct oral anticoagulants (DOACs) and low-molecular-weight heparins (LWMHs).

The origin of brain malignancies at the blood-brain barrier

Despite improvements in extracranial therapy, survival rate for patients suffering from brain metastases remains very poor. This is coupled with the incidence of brain metastases continuing to rise. In this review, we focus on core contributions of the blood-brain barrier to the origin of brain metastases. We first provide an overview of the structure and function of the blood-brain barrier under physiological conditions. Next, we discuss the emerging idea of a pre-metastatic niche, namely that secreted factors and extracellular vesicles from a primary tumor site are able to travel through the circulation and prime the neurovasculature for metastatic invasion. We then consider the neurotropic mechanisms that circulating tumor cells possess or develop that facilitate disruption of the blood-brain barrier and survival in the brain's parenchyma. Finally, we compare and contrast brain metastases at the blood-brain barrier to the primary brain tumor, glioma, examining the process of vessel co-option that favors the survival and outgrowth of brain malignancies.

Role of heparanase in sepsis‑related acute kidney injury (Review)

Sepsis-related acute kidney injury (S-AKI) is a common and significant complication of sepsis in critically ill patients, which can often only be treated with antibiotics and medications that reduce S-AKI symptoms. The precise mechanism underlying the onset of S-AKI is still unclear, thus hindering the development of new strategies for its treatment. Therefore, it is necessary to explore the pathogenesis of S-AKI to identify biomarkers and therapeutic targets for its early diagnosis and treatment. Heparanase (HPA), the only known enzyme that cleaves the side chain of heparan sulfate, has been widely studied in relation to tumor metabolism, procoagulant activity, angiogenesis, inflammation and sepsis. It has been reported that HPA plays an important role in the progression of S-AKI. The aim of the present review was to provide an overview of the function of HPA in S-AKI and to summarize its underlying molecular mechanisms, including mediating inflammatory response, immune response, autophagy and exosome biogenesis. It is anticipated that emerging discoveries about HPA in S-AKI will support HPA as a potential biomarker and therapeutic target to combat S-AKI.

Discovery and development of small-molecule heparanase inhibitors

Heparanase-1 (HPSE) is a promising yet challenging therapeutic target. It is the only known enzyme that is responsible for cleavage of heparan sulfate (HS) side chains from heparan sulfate proteoglycans (HSPGs), and is the key enzyme involved in the remodeling and degradation of the extracellular matrix (ECM). Overexpression of HPSE is found in various types of diseases, including cancers, inflammations, diabetes, and viral infections. Inhibiting HPSE can restore ECM functions and integrity, making the development of HPSE inhibitors a highly sought-after topic. So far, all HPSE inhibitors that have entered clinical trials belong to the category of HS mimetics, and no small-molecule or drug-like HPSE inhibitors have made similar progress. None of the HS mimetics have been approved as drugs, with some clinical trials discontinued due to poor bioavailability, side effects, and unfavorable pharmacokinetics characteristics. Small-molecule HPSE inhibitors are, therefore, particularly appealing due to their drug-like characteristics. Advances in the chemical spaces and drug design technologies, including the increasing use of in vitro and in silico screening methods, have provided new opportunities in drug discovery. This article aims to review the discovery and development of small-molecule HPSE inhibitors via screening strategies to shed light on the future endeavors in the development of novel HPSE inhibitors.

Heparanase-A single protein with multiple enzymatic and nonenzymatic functions

Heparanase (Hpa1) is expressed by tumor cells and cells of the tumor microenvironment and functions extracellularly to remodel the extracellular matrix (ECM) and regulate the bioavailability of ECM-bound factors, augmenting, among other effects, gene transcription, autophagy, exosome formation, and heparan sulfate (HS) turnover. 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 enzyme appears to fulfill some normal functions associated, for example, with vesicular traffic, lysosomal-based secretion, autophagy, HS turnover, and gene transcription. It activates cells of the innate immune system, promotes the formation of exosomes and autophagosomes, and stimulates signal transduction pathways via enzymatic and nonenzymatic activities. These effects dynamically impact multiple regulatory pathways that together drive tumor growth, dissemination, and drug resistance as well as inflammatory responses. The emerging premise is that heparanase expressed by tumor cells, immune cells, endothelial cells, and other cells of the tumor microenvironment is a key regulator of the aggressive phenotype of cancer, an important contributor to the poor outcome of cancer patients and a valid target for therapy. So far, however, antiheparanase-based therapy has not been implemented in the clinic. Unlike heparanase, heparanase-2 (Hpa2), a close homolog of heparanase (Hpa1), does not undergo proteolytic processing and hence lacks intrinsic HS-degrading activity, the hallmark of heparanase. Hpa2 retains the capacity to bind heparin/HS and exhibits an even higher affinity towards HS than heparanase, thus competing for HS binding and inhibiting heparanase enzymatic activity. It appears that Hpa2 functions as a natural inhibitor of Hpa1 regulates the expression of selected genes that maintain tissue hemostasis and normal function, and plays a protective role against cancer and inflammation, together emphasizing the significance of maintaining a proper balance between Hpa1 and Hpa2.

Role of heparanase in ARDS through autophagy and exosome pathway (review)

Acute respiratory distress syndrome (ARDS) is the most common respiratory disease in ICU. Although there are many treatment and support methods, the mortality rate is still high. The main pathological feature of ARDS is the damage of pulmonary microvascular endothelium and alveolar epithelium caused by inflammatory reaction, which may lead to coagulation system disorder and pulmonary fibrosis. Heparanase (HPA) plays an significant role in inflammation, coagulation, fibrosis. It is reported that HPA degrades a large amount of HS in ARDS, leading to the damage of endothelial glycocalyx and inflammatory factors are released in large quantities. HPA can aggrandize the release of exosomes through syndecan-syntenin-Alix pathway, leading to a series of pathological reactions; at the same time, HPA can cause abnormal expression of autophagy. Therefore, we speculate that HPA promotes the occurrence and development of ARDS through exosomes and autophagy, which leads to a large amount of release of inflammatory factors, coagulation disorder and pulmonary fibrosis. This article mainly describes the mechanism of HPA on ARDS.

Insights into the Molecular Mechanisms Mediating Extravasation in Brain Metastasis of Breast Cancer, Melanoma, and Lung Cancer

Brain metastasis is an incurable end-stage of systemic cancer associated with poor prognosis, and its incidence is increasing. Brain metastasis occurs through a multi-step cascade where cancer cells spread from the primary tumor site to the brain. The extravasation of tumor cells through the blood-brain barrier (BBB) is a critical step in brain metastasis. During extravasation, circulating cancer cells roll along the brain endothelium (BE), adhere to it, then induce alterations in the endothelial barrier to transmigrate through the BBB and enter the brain. Rolling and adhesion are generally mediated by selectins and adhesion molecules induced by inflammatory mediators, while alterations in the endothelial barrier are mediated by proteolytic enzymes, including matrix metalloproteinase, and the transmigration step mediated by factors, including chemokines. However, the molecular mechanisms mediating extravasation are not yet fully understood. A better understanding of these mechanisms is essential as it may serve as the basis for the development of therapeutic strategies for the prevention or treatment of brain metastases. In this review, we summarize the molecular events that occur during the extravasation of cancer cells through the blood-brain barrier in three types of cancer most likely to develop brain metastasis: breast cancer, melanoma, and lung cancer. Common molecular mechanisms driving extravasation in these different tumors are discussed.

Heparin, Heparan Sulphate and Sepsis: Potential New Options for Treatment

Sepsis is a life-threatening hyperreaction to infection in which excessive inflammatory and immune responses cause damage to host tissues and organs. The glycosaminoglycan heparan sulphate (HS) is a major component of the cell surface glycocalyx. Cell surface HS modulates several of the mechanisms involved in sepsis such as pathogen interactions with the host cell and neutrophil recruitment and is a target for the pro-inflammatory enzyme heparanase. Heparin, a close structural relative of HS, is used in medicine as a powerful anticoagulant and antithrombotic. Many studies have shown that heparin can influence the course of sepsis-related processes as a result of its structural similarity to HS, including its strong negative charge. The anticoagulant activity of heparin, however, limits its potential in treatment of inflammatory conditions by introducing the risk of bleeding and other adverse side-effects. As the anticoagulant potency of heparin is largely determined by a single well-defined structural feature, it has been possible to develop heparin derivatives and mimetic compounds with reduced anticoagulant activity. Such heparin mimetics may have potential for use as therapeutic agents in the context of sepsis.

A Universal and Modular Scaffold for Heparanase Activatable Probes and Drugs

Heparanase (HPSE) is an endo-β-glucuronidase involved in extracellular matrix remodeling in rapidly healing tissues, most cancers and inflammation, and viral infection. Its importance as a therapeutic target warrants further study, but such is hampered by a lack of research tools. To expand the toolkits for probing HPSE enzymatic activity, we report the design of a substrate scaffold for HPSE comprised of a disaccharide substrate appended with a linker, capable of carrying cargo until being cleaved by HPSE. Here exemplified as a fluorogenic, coumarin-based imaging probe, this scaffold can potentially expand the availability of HPSE-responsive imaging or drug delivery tools using a variety of imaging moieties or other cargo. We show that electronic tuning of the scaffold provides a robust response to HPSE while simplifying the structural requirements of the attached cargo. Molecular docking and modeling suggest a productive probe/HPSE binding mode. These results further support the hypothesis that the reactivity of these HPSE-responsive probes is predominantly influenced by the electron density of the aglycone. This universal HPSE-activatable scaffold will greatly facilitate future development of HPSE-responsive probes and drugs.

Enzymatic Digestion of Cell-surface Heparan Sulfate Alters the Radiation Response in Triple-negative Breast Cancer Cells

BACKGROUND AND AIM

Radiation resistance represents a major challenge in the treatment of breast cancer. As heparan sulfate (HS) chains are known to contribute to tumorigenesis, we aimed to investigate the interplay between HS degradation and radiation response in triple-negative breast cancer (TNBC) cells.

METHODS

HS chains were degraded in vitro as TNBC cells MDA-MB-231 and HCC1806 were treated with heparinase I and III. Subsequently, radioresistance was determined via colony formation assay after doses of 2, 4 and 6 Gy. Cell cycle profile, stem cell characteristics, expression of HS, activation of beta integrins, and apoptosis were determined by flow cytometry. Additionally, cell motility was analyzed via wound-healing assays, and expression and activation of FAK, CDK-6, Src, and Erk1/2 were quantified by western blot pre- and post-irradiation. Finally, the expression of cytokines was analyzed using a cytokine array.

RESULTS

Radiation promoted cell cycle changes, while heparinase treatment induced apoptosis in both cell lines. Colony formation assays showed significantly increased radio-resistance for both cell lines after degradation of HS. Cell migration was similarly upregulated after degradation of HS compared to controls. This effect was even more prominent after irradiation. Interestingly, FAK, a marker of radioresistance, was significantly activated in the heparinase-treated group. Additionally, we found Src to be dysregulated in MDA-MB-231 cells. Finally, we observed differential secretion of GRO, CXCL1, IGFBP1, IL8, Angiogenin, and Osteoprotegerin after HS degradation and radiotherapy.

CONCLUSION

Our results suggest an influence of HS chains on the development of radioresistance in TNBC.

Mixed computational-experimental study to reveal the anti-metastasis and anti-angiogenesis effects of Astragalin in human breast cancer

BACKGROUND

Breast cancer is the most aggressive malignant tumor with high morbidity and mortality. Astragalin, a flavonoid widely found in a variety of edible and medicinal plants, is recorded to possess multiple biological and pharmacological activities. However, its effect of anti-breast cancer has been unknown.

METHODS

Computational pharmacology was employed to explore the potential mechanism of anti-metastasis and anti-angiogenesis effects of Astragalin on breast cancer. The targets of Astragalin were obtained from TCMSP, Swiss Target Prediction, SEA, BATMAN-TCM, ChemMapper and STITCH databases, and targets of breast cancer were got from OMIM, GeneCards, and DisGeNET databases. Protein-protein interaction network (PPI), Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed to elucidate the interactions of these two groups of targets. Moreover, the anti-metastasis and anti-angiogenesis effects of Astragalin were validated by in vitro and in vivo experiments using wound healing assay, transwell migration and invasion assay, gelatin zymography assay, tube formation assay, and chick embryo chorioallantoic membrane model.

RESULTS

Computational pharmacology analysis indicated that the effects of Astragalin against breast cancer were mainly related to the regulation of the cell movement, migration, and angiogenesis, and taking AKT, ZEB1, VEGF, and MMP9 as the promising targets. Further experimental pharmacology indicated that Astragalin exerted anti-metastasis and anti-angiogenesis activities on breast cancer, and verified AKT, ZEB1, VEGF, and MMP9 as the key targets.

CONCLUSION

Astragalin suppresses the metastasis and angiogenesis of breast cancer, and AKT, ZEB1, VEGF, and MMP9 are the promising targets for Astragalin against breast cancer. Thus, Astragalin is a potential therapeutic agent for breast cancer.

Heparanase: A Novel Therapeutic Target for the Treatment of Atherosclerosis

Cardiovascular disease (CVD) is the leading cause of death and disability worldwide, and its management places a huge burden on healthcare systems through hospitalisation and treatment. Atherosclerosis is a chronic inflammatory disease of the arterial wall resulting in the formation of lipid-rich, fibrotic plaques under the subendothelium and is a key contributor to the development of CVD. As such, a detailed understanding of the mechanisms involved in the development of atherosclerosis is urgently required for more effective disease treatment and prevention strategies. Heparanase is the only mammalian enzyme known to cleave heparan sulfate of heparan sulfate proteoglycans, which is a key component of the extracellular matrix and basement membrane. By cleaving heparan sulfate, heparanase contributes to the regulation of numerous physiological and pathological processes such as wound healing, inflammation, tumour angiogenesis, and cell migration. Recent evidence suggests a multifactorial role for heparanase in atherosclerosis by promoting underlying inflammatory processes giving rise to plaque formation, as well as regulating lesion stability. This review provides an up-to-date overview of the role of heparanase in physiological and pathological processes with a focus on the emerging role of the enzyme in atherosclerosis.

Importance of Heparan Sulfate Proteoglycans in Pancreatic Islets and β-Cells

β-cells in the islets of Langerhans of the pancreas secrete insulin in response to the glucose concentration in the blood. When these pancreatic β-cells are damaged, diabetes develops through glucose intolerance caused by insufficient insulin secretion. High molecular weight polysaccharides, such as heparin and heparan sulfate (HS) proteoglycans, and HS-degrading enzymes, such as heparinase, participate in the protection, maintenance, and enhancement of the functions of pancreatic islets and β-cells, and the demand for studies on glycobiology within the field of diabetes research has increased. This review introduces the roles of complex glycoconjugates containing high molecular weight polysaccharides and their degrading enzymes in pancreatic islets and β-cells, including those obtained in studies conducted by us earlier. In addition, from the perspective of glycobiology, this study proposes the possibility of application to diabetes medicine.

Exosomes, autophagy and ER stress pathways in human diseases: Cross-regulation and therapeutic approaches

Exosomal release pathway and autophagy together maintain homeostasis and survival of cells under stressful conditions. Autophagy is a catabolic process through which cell entities, such as malformed biomacromolecules and damaged organelles, are degraded and recycled via the lysosomal-dependent pathway. Exosomes, a sub-type of extracellular vesicles (EVs) formed by the inward budding of multivesicular bodies (MVBs), are mostly involved in mediating communication between cells. The unfolded protein response (UPR) is an adaptive response that is activated to sustain survival in the cells faced with the endoplasmic reticulum (ER) stress through a complex network that involves protein synthesis, exosomes secretion and autophagy. Disruption of the critical crosstalk between EVs, UPR and autophagy may be implicated in various human diseases, including cancers and neurodegenerative diseases, yet the molecular mechanism(s) behind the coordination of these communication pathways remains obscure. Here, we review the available information on the mechanisms that control autophagy, ER stress and EV pathways, with the view that a better understanding of their crosstalk and balance may improve our knowledge on the pathogenesis and treatment of human diseases, where these pathways are dysregulated.

Role of Heparanase and Syndecan-1 in HSV-1 Release from Infected Cells

Herpes Simplex Virus 1 (HSV-1) is a neurotropic human virus that belongs to the Alphaherpesvirinae subfamily of Herpesviridae. Establishment of its productive infection and progression of disease pathologies depend largely on successful release of virions from the virus-producing cells. HSV-1 is known to exploit many host factors for its release. Recent studies have shown that heparanase (HPSE) is one such host enzyme that is recruited for this purpose. It is an endoglycosidase that cleaves heparan sulfate (HS) from the surface of infected cells. HS is a virus attachment coreceptor that is commonly found on cell surfaces as HS proteoglycans e.g., syndecan-1 (SDC-1). The current model suggests that HSV-1 during the late stage of infection upregulates HPSE, which in turn enhances viral release by removing the virus-trapping HS moieties. In addition to its role in directly enabling viral release, HPSE accelerates the shedding of HS-containing ectodomains of SDC-1, which enhances HSV-1 release via a similar mechanism by upregulating CREB3 and COPII proteins. This review outlines the role of HPSE and SDC-1 as newly assigned host factors that facilitate HSV-1 release during a lytic infection cycle.

Heparanase 2 (Hpa2) attenuates the growth of human sarcoma

The pro-tumorigenic properties of heparanase are well documented and established. In contrast, the role of heparanase 2 (Hpa2), a close homolog of heparanase, in cancer is not entirely clear. In carcinomas, Hpa2 is thought to attenuate tumor growth, possibly by inhibiting heparanase enzymatic activity. Here, we examine the role of Hpa2 in sarcoma, a group of rare tumors of mesenchymal origin, accounting for approximately 1% of all malignant tumors. Consistently, we found that overexpression of Hpa2 attenuates tumor growth while Hpa2 gene silencing results in bigger tumors. Mechanistically, attenuation of tumor growth by Hpa2 was associated with increased tumor stress conditions, involving ER stress, hypoxia, and JNK phosphorylation, leading to increased apoptotic cell death. In addition, overexpression of Hpa2 induces the expression of the p53 family member, p63 which, in sarcoma, functions to attenuate tumor growth. Moreover, we show that Hpa2 profoundly reduces stem cell characteristics of the sarcoma cells (stemness), most evident by failure of Hpa2 cells to grow as spheroids typical of stem cells. Likewise, expression of CD44, a well-established stem cell marker, was prominently decreased in Hpa2 cells. CD44 is also a cell surface receptor for hyaluronic acid (HA), a nonsulfated glycosaminoglycan that is enriched in connective tissues. Reduced expression of CD44 by Hpa2 may thus represent impaired cross-talk between Hpa2 and the extracellular matrix. Clinically, we found that Hpa2 is expressed by leiomyosarcoma tumor biopsies. Interestingly, nuclear localization of Hpa2 was associated with low-stage tumors. This finding opens a new direction in Hpa2 research.

Heparanase regulates EMT and cancer stem cell properties in prostate tumors

Prostate cancer displays a certain phenotypic plasticity that allows for the transition of cells from the epithelial to the mesenchymal state. This process, known as epithelial–mesenchymal transition (EMT), is one of the factors that give the tumor cells greater invasive and migratory capacity with subsequent formation of metastases. In addition, many cancers, including prostate cancer, are derived from a cell population that shows the properties of stem cells. These cells, called cancer stem cells (CSCs) or tumor-initiating cells, not only initiate the tumor process and growth but are also able to mediate metastasis and drug resistance. However, the impact of EMT and CSCs in prostate cancer progression and patient survival is still far from fully understood. Heparanase (HPSE), the sole mammalian endoglycosidase capable of degrading heparan sulfate (HS), is also involved in prostate cancer progression. We had previously proved that HPSE regulates EMT in non-cancerous pathologies. Two prostate cancer cell lines (DU145 and PC3) were silenced and overexpressed for HPSE. Expression of EMT and stemness markers was evaluated. Results showed that the expression of several EMT markers are modified by HPSE expression in both the prostate cancer cell lines analyzed. In the same way, the stemness markers and features are also modulated by HPSE expression. Taken together, the present findings seem to prove a new mechanism of action of HPSE in sustaining prostate cancer growth and diffusion. As for other tumors, these results highlight the importance of HPSE as a potential pharmacological target in prostate cancer treatment.

miR-429 negatively regulates the progression of hypoxia-induced retinal neovascularization by the HPSE-VEGF pathway

Heparanase (HPSE) and vascular endothelial growth factor (VEGF) are believed to play a vital role in hypoxia-induced retinal neovascularization (RNV). HPSE is a target gene of miR-429. Our study aimed to investigate the effect of the miR-429-HPSE-VEGF pathway on hypoxia-induced RNV. The gene and protein expression of miR-429, HPSE and VEGF in human retinal endothelial cells and retinas was determined by real-time PCR and Western blot assays. The effects of miR-429 on human retinal endothelial cells and retinal neovascularization under hypoxia condition were verified by in vitro and in vivo experiments. First, we studied the effect of the miR-429-HPSE-VEGF pathway in HRECs under hypoxic conditions. HREC functions such as migration and tube formation were enhanced under hypoxic conditions. Overexpression of miR-429 in HRECs reversed these changes. Then, we investigated the effect of miR-429 on hypoxia-induced RNV in vivo. When miR-429 agomirs were injected into the vitreous cavity of mice with oxygen-induced retinopathy to overexpress miR-429, the mRNA and protein expression of VEGF was significantly reduced. In addition, indicators of retinal neovascularization, such as the retinal avascular area, and morphology of vessels, were reduced significantly in the miR-429 overexpression group. In this study, our data showed that miR-429 plays an important role by inhibiting the HPSE-VEGF pathway in hypoxia-induced retinopathy.

Heparanase is a prognostic biomarker independent of tumor purity and hypoxia based on bioinformatics and immunohistochemistry analysis of esophageal squamous cell carcinoma

Background

Esophageal squamous cell carcinoma (ESCC) is a common malignant tumor of the digestive tract with a poor prognosis. The tumor microenvironment (TME) is mainly composed of tumor cells, stromal cells, and immune cells and plays an important role in ESCC development. There are substantial differences in tumor purity among different parts of ESCC tissues, consisting of distinct immune and stromal cells and variations in the status of hypoxia. Thus, prognostic models of ESCC based on bioinformatic analysis of tumor tissues are unreliable.

Method

Differentially expressed genes (DEGs) independent of tumor purity and hypoxia were screened by Spearman correlation analysis of public ESCC cohorts. Subsequently, the DEGs were subjected to Cox regression analysis. Then, we constructed a protein–protein interaction (PPI) network of the DEGs using Cytoscape. Intersection analysis of the univariate Cox and PPI results indicated that heparanase (HPSE), an endo-β-D-glucuronidase capable of cleaving heparan sulfate side chains, was a predictive factor. Gene set enrichment analysis (GSEA) was used to reveal the potential function of HPSE, and single-cell sequencing data were analyzed to evaluate the distribution of HPSE in immune cells. Furthermore, a human ESCC tissue microarray was used to validate the expression and prognostic value of HPSE.

Result

We found that HPSE was downregulated in ESCC tissues and was not correlated with tumor purity or hypoxia status. HPSE is involved in multiple biological processes. ESCC patients with low HPSE expression in cancerous tissues exhibited poor prognosis.

Conclusions

These results indicate that low HPSE expression in cancerous tissues correlates with poor prognosis in patients with ESCC. HPSE is a novel prognostic biomarker independent of tumor purity and hypoxia status in ESCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-022-02698-9.

Circulating Exosome Cargoes Contain Functionally Diverse Cancer Biomarkers: From Biogenesis and Function to Purification and Potential Translational Utility

Although diagnostic and therapeutic treatments of cancer have tremendously improved over the past two decades, the indolent nature of its symptoms has made early detection challenging. Thus, inter-disciplinary (genomic, transcriptomic, proteomic, and lipidomic) research efforts have been focused on the non-invasive identification of unique "silver bullet" cancer biomarkers for the design of ultra-sensitive molecular diagnostic assays. Circulating tumor biomarkers, such as CTCs and ctDNAs, which are released by tumors in the circulation, have already demonstrated their clinical utility for the non-invasive detection of certain solid tumors. Considering that exosomes are actively produced by all cells, including tumor cells, and can be found in the circulation, they have been extensively assessed for their potential as a source of circulating cell-specific biomarkers. Exosomes are particularly appealing because they represent a stable and encapsulated reservoir of active biological compounds that may be useful for the non-invasive detection of cancer. T biogenesis of these extracellular vesicles is profoundly altered during carcinogenesis, but because they harbor unique or uniquely combined surface proteins, cancer biomarker studies have been focused on their purification from biofluids, for the analysis of their RNA, DNA, protein, and lipid cargoes. In this review, we evaluate the biogenesis of normal and cancer exosomes, provide extensive information on the state of the art, the current purification methods, and the technologies employed for genomic, transcriptomic, proteomic, and lipidomic evaluation of their cargoes. Our thorough examination of the literature highlights the current limitations and promising future of exosomes as a liquid biopsy for the identification of circulating tumor biomarkers.

Heparanase-1 is upregulated by hepatitis C virus and favors its replication

BACKGROUND & AIMS

Over time, chronic HCV infection can lead to hepatocellular carcinoma (HCC), a process that involves changes to the liver extracellular matrix (ECM). However, the exact mechanisms by which HCV induces HCC remain unclear. Therefore, we sought to investigate the impact of HCV on the liver ECM, with a focus on heparanase-1 (HPSE).

METHODS

HPSE expression was assessed by quantitative reverse-transcription PCR, immunoblotting and immunofluorescence in liver biopsies infected or not with HCV, and in 10-day-infected hepatoma Huh7.5 cells. Cell lines deficient for or overexpressing HPSE were established to study its role during infection.

RESULTS

HCV propagation led to significant HPSE induction, in vivo and in vitro. HPSE enhanced infection when exogenously expressed or supplemented as a recombinant protein. Conversely, when HPSE expression was downregulated or its activity blocked, HCV infection dropped, suggesting a role of HPSE in the HCV life cycle. We further studied the underlying mechanisms of such observations and found that HPSE favored HCV release by enhancing CD63 synthesis and exosome secretion, but not by stimulating HCV entry or genome replication. We also showed that virus-induced oxidative stress was involved in HPSE induction, most likely through NF-κB activation.

CONCLUSIONS

We report for the first time that HCV infection is favored by HPSE, and upregulates HPSE expression and secretion, which may result in pathogenic alterations of the ECM.

LAY SUMMARY

Chronic hepatitis C virus (HCV) infection can lead to hepatocellular carcinoma development in a process that involves derangement of the extracellular matrix (ECM). Herein, we show that heparanase-1, a protein involved in ECM degradation and remodeling, favors HCV infection and is upregulated by HCV infection; this upregulation may result in pathogenic alterations of the ECM.

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.

Molecular characterization and expression of RPS23 and HPSE and their association with hematologic parameters in sheep

Ribosomal protein S23 (RPS23) and Heparanase (HPSE) were located on chromosome 5 and chromosome 6, respectively, which play vital roles in protein synthesis and immunity. The objective of this study was to clone RPS23 and HPSE and to detect the expression levels of RPS23 and HPSE and the polymorphisms of RPS23 and HPSE associated with the hematologic parameters by using qRT-PCR, DNA sequencing and KASPar assay. The quantitative real-time PCR (RT-qPCR) showed that the two genes were expressed widely in the ten tissues of sheep. The expression levels of RPS23 and HPSE were the highest in lung and liver, respectively. The expression levels of RPS23 and HPSE in lung and liver increased from 0 to 3 months, decreased from 3 to 6 months, respectively. Furthermore, two mutations g.720 A > G and g.1077 G > A were detected in the RPS23 and HPSE, respectively, which were confirmed to be significantly associated with hematologic parameters. These results supported RPS23 g.720 A > G and HPSE g.1077 G > A as genetic markers of sheep.

Acute T-Cell-Driven Inflammation Requires the Endoglycosidase Heparanase-1 from Multiple Cell Types

It has been accepted for decades that T lymphocytes and metastasising tumour cells traverse basement membranes (BM) by deploying a battery of degradative enzymes, particularly proteases. However, since many redundant proteases can solubilise BM it has been difficult to prove that proteases aid cell migration, particularly in vivo. Recent studies also suggest that other mechanisms allow BM passage of cells. To resolve this issue we exploited heparanase-1 (HPSE-1), the only endoglycosidase in mammals that digests heparan sulfate (HS), a major constituent of BM. Initially we examined the effect of HPSE-1 deficiency on a well-characterised adoptive transfer model of T-cell-mediated inflammation. We found that total elimination of HPSE-1 from this system resulted in a drastic reduction in tissue injury and loss of target HS. Subsequent studies showed that the source of HPSE-1 in the transferred T cells was predominantly activated CD4⁺ T cells. Based on bone marrow chimeras, two cellular sources of HPSE-1 were identified in T cell recipients, one being haematopoiesis dependent and the other radiation resistant. Collectively our findings unequivocally demonstrate that an acute T-cell-initiated inflammatory response is HPSE-1 dependent and is reliant on HPSE-1 from at least three different cell types.

Transcription factor Runx2 changes the expression of some matricellular proteins in metastatic breast cancer cells

BACKGROUND

Runx2 is one of the runt-related genes that are overexpressed in human cancers and contribute to metastasis. The cancer cell metastasis requires modifications of the extracellular matrix (ECM) and reduction in ECM-cell interaction. This process is performed by various enzymes and proteins secreted by cancer and surrounding cells. This study aimed to investigate the effect of the Runx2 transcription factor on the expression of matricellular proteins such as HPA1, LOX, SPARC, and OPN, which have important roles in ECM modification and ECM-cell interaction in human breast cancer. Also, the changes in their associated oncogenic pathways including Akt, Erk, FAK activities, and c-jun protein expression were investigated.

METHODS AND RESULTS

Runx2 knockdown model was created using runx2 siRNA in MDA-MB-231 human metastatic breast cancer cells. The changes in the mRNA and protein expressions of ECM proteins were shown by the qPCR and Western blotting, respectively. The results showed that there was a decrease in both mRNA and protein expressions of HPA1, SPARC, and LOX, whereas there was no change in those of OPN. Phosphorylated Akt, Erk, FAK levels, and protein expression of c-jun, however, decreased in the cells.

CONCLUSION

Our results revealed that Runx2 affected matricellular protein expression, which is important for metastasis and invasion of breast cancer. Hence, we have concluded that runx2 appears to be efficient for regulating breast cancer metastasis through an expression of matricellular proteins.

Synthesis of novel glycolipid mimetics of heparan sulfate and their application in colorectal cancer treatment in a mouse model

Heparan sulfate (HS) is a highly sulfated natural carbohydrate that plays crucial roles in cancer, inflammation, and angiogenesis. Heparanase (HPSE) is the sole HS degrading endoglycosidase that cleaves HS at structure‐dependent sites along the polysaccharide chain. Overexpression of HPSE by cancer cells correlates with increased tumor size and enhanced metastasis. Previously we have shown that a tetramer HS mimetic is a potent HPSE inhibitor displaying remarkable anticancer activity in vivo. Building on that work, we report the synthesis and testing of a novel library of single entity trimer glycolipid mimetics that effectively inhibit HPSE at low nanomolar concentrations. A lipophilic arm was introduced to assess whether an improvement of pharmacokinetics and plasma residence time would offset the reduction in charge and multivalency. Preclinical tests in a mouse syngeneic model showed effective tumor growth inhibition by the tetramer but not the trimer glycomimetic.

Pharmacological Inhibition of Exosome Machinery: An Emerging Prospect in Cancer Therapeutics

Abstract:

Exosomes are nanocarriers that mediate intercellular communication, crucial for normal physiological functions. However, exponentially emerging reports have correlated their dysregulated release with various pathologies, including cancer. In cancer, from stromal remodeling to metastasis, where tumor cells bypass the immune surveillance and show drug resistivity, it has been established to be mediated via tumor-derived exosomes. Owing to their role in cancer pathogenicity, exosome-based strategies offer enormous potential in treatment regimens. These strategies include the use of exosomes as a drug carrier or as an immunotherapeutic agent, which requires advanced nanotechnologies for exosome isolation and characterization. In contrast, pharmacological inhibition of exosome machinery surpasses the requisites of nanotechnology and thus emerges as an essential prospect in cancer therapeutics. In this line, researchers are currently trying to dissect the molecular pathways to reveal the involvement of key regulatory proteins that facilitate the release of tumor-derived exosomes. Subsequently, screening of various molecules in targeting these proteins, with eventual abatement of exosome-induced cancer pathogenicity, is being done. However, their clinical translation requires more extensive studies. Here we comprehensively review the molecular mechanisms regulating exosome release in cancer. Moreover, we give insight into the key findings that highlight the effect of various drugs as exosome blockers, which will add to the route of drug development in cancer management.

Heparanase as active player in endothelial glycocalyx remodeling

The surface of all animal cells is coated with a layer of carbohydrates linked in various ways to the outer side of the plasma membrane. These carbohydrates are mainly bound to proteins in the form of glycoproteins and proteoglycans and together with the glycolipids constitute the so-called glycocalyx. In particular, the endothelial glycocalyx that covers the luminal layer of the endothelium is composed of glycosaminoglycans (heparan sulphate -HS and hyaluronic acid -HA), proteoglycans (syndecans and glypicans) and adsorbed plasma proteins. Thanks to its ability to absorb water, this structure contributes to making the surface of the vessels slippery but at the same time acts by modulating the mechano-transduction of the vessels, the vascular permeability and the adhesion of leukocytes in thus regulating several physiological and pathological events. Among the various enzymes involved in the degradation of the glycocalyx, heparanase (HPSE) has been shown to be particularly involved. This enzyme is responsible for the cutting of heparan sulfate (HS) chains at the level of the proteoglycans of the endothelial glycocalyx whose dysfunction appears to have a role in organ fibrosis, sepsis and viral infection. In this mini-review, we describe the mechanisms by which HPSE contributes to glycocalyx remodeling and then examine the role of glycocalyx degradation in the development of pathological conditions and pharmacological strategies to preserve glycocalyx during disease pathogenesis.

Role of heparinase in the gastrointestinal dysfunction of sepsis (Review)

Heparinase (HPA) is a β-D glucuronidase that belongs to the endoglycosidase enzyme family, and plays an important role in numerous pathological and physiological processes, including inflammation, angiogenesis and tumor metastasis. When the expression of HPA is abnormally high, the side chain of heparin sulfate proteoglycans degrades, destroying the cell barrier and leading to the occurrence and development of inflammation, with systemic inflammation occurring in severe cases. Sepsis is a major cause of mortality in critically ill patients. In sepsis, the gastrointestinal tract is the first and most frequently involved target organ, which often leads to gastrointestinal dysfunction. HPA overexpression has been determined to accelerate sepsis progression and gastrointestinal dysfunction; thus, it was hypothesized that HPA may play an important role and may serve as an index for the diagnosis of gastrointestinal dysfunction in sepsis. HPA inhibitors may therefore become applicable as targeted drugs for the treatment of gastrointestinal dysfunction in patients with sepsis. The present review mainly discussed the role of HPA in gastrointestinal dysfunction of sepsis.

Cancer and Apoptosis

Cancer is an uncontrolled growth of normal cells due to unchecked regulatory mechanisms working inside the rapidly dividing cells. In this complex cancer disease treatment, various strategies are utilized to get rid of cancer cells effectively. The different methods combine approaches used to treat cancer, such as radiotherapy, surgery, and chemotherapy. Chemotherapy is among the most effective ways, along with radiotherapy and surgical removal of cancer tissue. Effective chemotherapy based on modification of conventional drugs along with various molecular therapeutic targets, which involve different inhibitors that work in a specific manner in inhibiting particular events activated in cancer cells-the understanding of molecular signaling pathways holds key in the development of targeted therapeutics. After the fundamental signaling pathway studies, a single signaling pathway targeting approach or multiple targeting could display remarkable results in cancer therapeutics. The signal approach includes the signal pathway target. However, a double targeted pathway could effectively aid in inhibiting cell growth or metastasis either due to triggering natural suicidal mechanism (apoptosis) activation. The particular environment of cells regulates cell growth and differentiation. Various proteins in the extracellular matrix (ECM) regulate the process of cancer initiation or progression. The ECM collagens, elastins proteins, fibronectins, and laminins might reduce the effectiveness of treatment therapy, reflecting them as an essential target. Any dysregulation in the composition of ECM reflects the regulatory ineffectiveness in a particular area. These have an association with poor prognosis, cell propagation, and metastasis, along drug resistance.Regulation in physiological processes associated with developmental process and maintaining the homeostasis. The pathogenesis of cancer might be connected to dysregulation in cell death programs, including autophagy, necrosis, and the most desirable cell death mechanism called apoptosis: programmed cell death, the highly regulatory mechanism of natural cell death involved in tissue development. The apoptosis involves characteristic feather of cell death which includes specific morphological change along with biochemical alteration. It includes tightly regulated irreversible events, i.e., phosphatidylserine externalization and DNA fragmentation, mainly via the intrinsic and extrinsic pathways. Targeting apoptosis in the development of therapeutics could be the ultimate process in treating cancer via chemotherapy. During apoptosis, cell death occurs without causing much damage or inflammation in neighboring cells. Various pro-apoptosis and anti-apoptosis proteins involved in the regulation of apoptosis could act as a remarkable target. The apoptosis inactivation is the critical dysregulatory process in the majority of cancer types. There is an increase in research development regarding apoptosis-targeted therapeutics. A understanding of apoptotic signaling pathways, a fundamental knowledge, aids in developing particular inhibitors for anti-apoptotic and activator of pro-apoptotic proteins.In both apoptosis pathways (extrinsic and intrinsic), pro-apoptotic and anti-apoptotic proteins act as potential regulators in cell division and growth. The pro-apoptotic proteins Bax trigger the activation of the intrinsic pathway, an excellent target for developing therapeutics, and are currently in clinical trials. Similarly, the inhibitor of the anti-apoptotic proteins is also on track in the drug development process. The considerable importance of apoptosis-based anticancer drugs is also due to improving the drug sensitivity via reversing the resistive mechanisms in cancer cells. The dysregulatory or inactivated apoptosis mechanism involve Bcl-2 family proteins which include both pro-apoptotic members downregulation and anti-apoptotic upregulation, various inhibitors of apoptosis as inhibitory proteins (IAPs), cell cycle dysregulation, dysregulatory repair system, cell progression pathway activation of NF-κB, tumor suppressor (p53) regulation, and death receptors (DRs) of the extrinsic pathway.

Heparanase-Induced Activation of AKT Stabilizes β-Catenin and Modulates Wnt/β-Catenin Signaling during Herpes Simplex Virus 1 Infection

Under pathological conditions like herpes simplex virus 1 (HSV-1) infection, host-pathogen interactions lead to major reconstruction of the host protein network, which contributes to the dysregulation of signaling pathways and disease onset. Of note is the upregulation of a multifunctional host protein, heparanase (HPSE), following infection, which serves as a mediator in HSV-1 replication. In this study, we identify a novel function of HPSE and highlight it as a key regulator of β-catenin signal transduction. The regulatory role of HPSE on the activation, nuclear translocation, and signal transduction of β-catenin disrupts cellular homeostasis and establishes a pathogenic environment that promotes viral replication. Under normal physiological conditions, β-catenin is bound to a group of proteins, referred to as the destruction complex, and targeted for ubiquitination and, ultimately, degradation. We show that virus-induced upregulation of HPSE leads to the activation of Akt and subsequent stabilization and activation of β-catenin through (i) the release of β-catenin from the destruction complex, and (ii) direct phosphorylation of β-catenin at Ser552. This study also provides an in-depth characterization of the proviral role of β-catenin signaling during HSV-1 replication using physiologically relevant cell lines and in vivo models of ocular infection. Furthermore, pharmacological inhibitors of this pathway generated a robust antiviral state against multiple laboratory and clinical strains of HSV-1. Collectively, our findings assign a novel regulatory role to HPSE as a driver of β-catenin signaling in HSV-1 infection. IMPORTANCE Heparanase (HPSE) and β-catenin have independently been implicated in regulating key pathophysiological processes, including neovascularization, angiogenesis, and inflammation; however, the relationship between the two proteins has remained elusive thus far. For that reason, characterizing this relationship is crucial and can lead to the development of novel therapeutics. For HSV-1 specifically, current antivirals are not able to abolish the virus from the host, leaving patients susceptible to episodes of viral reactivation. Identifying a host-based intervention can provide a better alternative with enhanced efficacy and sustained relief.

T cells promote metastasis by regulating extracellular matrix remodeling following chemotherapy

Metastasis is the main cause of cancer-related mortality. Despite intense efforts to understand the mechanisms underlying the metastatic process, treatment of metastatic cancer is still challenging. Here we describe a chemotherapy-induced, host-mediated mechanism that promotes remodeling of the extracellular matrix (ECM), ultimately facilitating cancer cell seeding and metastasis. Paclitaxel (PTX) chemotherapy enhanced rapid ECM remodeling and mechano-structural changes in the lungs of tumor-free mice, and the protein expression and activity of the ECM remodeling enzyme lysyl oxidase (LOX) increased in response to PTX. A chimeric mouse mode harboring genetic LOX depletion revealed chemotherapy-induced ECM remodeling was mediated by CD8+ T cells expressing LOX. Consistently, adoptive transfer of CD8+ T cells, but not CD4+ T cells or B cells, from PTX-treated mice to naïve immuno-deprived mice induced pulmonary ECM remodeling. Lastly, in a clinically relevant metastatic breast carcinoma model, LOX inhibition counteracted the metastasis-promoting, ECM-related effects of PTX. This study highlights the role of immune cells in regulating ECM and metastasis following chemotherapy, suggesting that inhibiting chemotherapy-induced ECM remodeling represents a potential therapeutic strategy for metastatic cancer.

DAL-1/4.1B promotes the uptake of exosomes in lung cancer cells via Heparan Sulfate Proteoglycan 2 (HSPG2)

DAL-1/4.1B is frequently absent in lung cancer tissues, which is significantly related to the occurrence and development of lung cancer. In this research, we found that DAL-1/4.1B affected the uptake of exosomes by lung cancer cells. When the expression of DAL-1/4.1B increased and decreased, the ability of exosome uptake enhanced and attenuated correspondingly. And we found that when cells were treated with different vesicles uptake inhibitors (chlorpromazine, methyl-β-cyclodextrin (MβCD), cytochalasin D, chloroquine and heparin) and heparinase (HSPE), only heparin and HSPE counteracted the uptake enhancement effect caused by DAL-1/4.1B. Therefore, we speculated that DAL-1/4.1B might promote the uptake of exosomes through the heparan sulfate proteoglycans (HSPGs) pathway. After screening the expression of HSPGs and HSPE in H292 cells, the expression of heparan sulfate proteoglycan 2 (HSPG2) increased with overexpression of DAL-1/4.1B and decreased with knockdown of DAL-1/4.1B. Meanwhile, exosome uptake decreased with HSPG2 knockdown in H292 and DAL-1/4.1B-overexpressing H292 cells. Moreover, knockdown of DAL-1/4.1B and HSPG2 in lung cancer A549 cells resulted in a similar decrease in exosome uptake, and the expression of HSPG2 was also decreased with DAL-1/4.1B knockdown. These results indicated that HSPG2 directly affected the uptake of exosomes, while DAL-1/4.1B positively affected the expression of HSPG2. Therefore, DAL-1/4.1B may promote cellular adhesion and inhibit migration in cancer cells.

The HPSE Gene Insulator-A Novel Regulatory Element That Affects Heparanase Expression, Stem Cell Mobilization, and the Risk of Acute Graft versus Host Disease

The HPSE gene encodes heparanase (HPSE), a key player in cancer, inflammation, and autoimmunity. We have previously identified a strong HPSE gene enhancer involved in self-regulation of heparanase by negative feedback exerted in a functional rs4693608 single-nucleotide polymorphism (SNP) dependent manner. In the present study, we analyzed the HPSE gene insulator region, located in intron 9 and containing rs4426765, rs28649799, and rs4364254 SNPs. Our results indicate that this region exhibits HPSE regulatory activity. SNP substitutions lead to modulation of a unique DNA-protein complex that affects insulator activity. Analysis of interactions between enhancer and insulator SNPs revealed that rs4693608 has a major effect on HPSE expression and the risk of post-transplantation acute graft versus host disease (GVHD). The C alleles of insulator SNPs rs4364254 and rs4426765 modify the activity of the HPSE enhancer, resulting in altered HPSE expression and increased risk of acute GVHD. Moreover, rs4426765 correlated with HPSE expression in activated mononuclear cells, as well as with CD3 levels and lymphocyte counts following G-CSF mobilization. rs4363084 and rs28649799 were found to be associated with CD34⁺ levels. Our study provides new insight into the mechanism of HPSE gene regulation and its impact on normal and pathological processes in the hematopoietic system.

Understanding Hyaluronan Receptor (CD44) Interaction, HA-CD44 Activated Potential Targets in Cancer Therapeutics

Cancer is a complex mechanism involving a series of cellular events. The glycoproteins such as hyaluronan (HA) are a significant element of extracellular matrix (ECM), involve in the onset of cancer developmental process. The pivotal roles of HA in cancer progression depend on dysregulated expression in various cancer. HA, also gain attention due to consideration as a primary ligand of CD44 receptor. The CD44, complex transmembrane receptor protein, due to alternative splicing in the transcription process, various CD44 isoforms predominantly exist. The overexpression of distinct CD44 isoforms (CD44v) standard (CD44s) depends on the tumour type and stage. The receptor proteins, CD44 engage in a variety of biological processes, including cell growth, apoptosis, migration, and angiogenesis. HA-CD44 interaction trigger survival pathways that result in cell proliferation, invasion ultimately complex metastasis. The interaction and binding of ligand-receptor HA-CD44 regulate the downstream cytoskeleton pathways involve in cell survival or cell death. Thus, targeting HA, CD44 (variant and standard) isoform, and HA-CD44 binding consider as an attractive and useful approach towards cancer therapeutics. The use of various inhibitors of HA, hyaluronidases (HYALs), and utilizing targeted Nano-delivery of anticancer agents and antibodies against CD44, peptides gives promising results in vitro and in vivo. However, they are in clinical trials with favourable and unfavourable outcomes, which reflects the need for various modifications in targeting agents and a better understanding of potential targets in tumour progression pathways.

Emerging therapeutic targets for gastric cancer from a host-Helicobacter pylori interaction perspective

INTRODUCTION

Gastric cancer (GC) has the higher genetic, cytologic, and architectural heterogeneity compared to other gastrointestinal cancers. By inducing gastric inflammation, Helicobacter pylori (HP) may lead to GC through combining bacterial factors with host factors. In this regard, identification of the major therapeutic targets against the host-HP interactions plays a critical role in GC prevention, diagnosis, and treatment.

AREAS COVERED

This study offers new insights into the promising therapeutic targets against the angiogenesis, invasion, or metastasis of GC from a host-HP interaction perspective. To this end, MEDLINE, EMBASE, LILACS, AIM, and IndMed databases were searched for relevant articles since 1992.

EXPERT OPINION

Wnt signaling and COX pathway have a well-documented history in the genesis of GC by HP and might be considered as the most promising targets for early GC treatment. Destroying HP may decrease the risk of GC, but it cannot fully hinder the GC development induced by HP infection. Therefore, targeting HP-activated pathways, especially COX-2/Wnt/beta-catenin/VEGF, TLR2/TLR9/COX-2, COX2-PGE2, and NF-κB/COX-2, as well as EPHA2, MMPs, and miR-543/SIRT1 axis, can be an effective measure in the early treatment of GC. However, different clinical trials and large, multi-center cohorts are required to validate these potentially effective targets for GC therapy.

Role of heparanase 2 (Hpa2) in gastric cancer

We report that gastric cancer patients exhibiting high levels of heparanase 2 (Hpa2) survive longer. Similarly, mice administrated with gastric carcinoma cells engineered to overexpress Hpa2 produced smaller tumors and survived longer than mice administrated with control cells. These beneficial effects were found to associate with increased phosphorylation of AMP-activated protein kinase (AMPK) that play an instrumental role in cell metabolism and is situated at the center of a tumor suppressor network. We also found that MG132, an inhibitor of the proteasome that results in proteotoxic stress, prominently enhances Hpa2 expression. Notably, Hpa2 induction by MG132 appeared to be mediated by AMPK, thus establishing a loop that feeds itself where Hpa2 enhances AMPK phosphorylation that, in turn, induces Hpa2 expression, possibly leading to attenuation of gastric tumorigenesis.

Heparanase is highly implicated in tumor metastasis due to its capacity to cleave heparan sulfate and, consequently, remodel the extracellular matrix underlying epithelial and endothelial cells. In striking contrast, only little attention was given to its close homolog, heparanase 2 (Hpa2), possibly because it lacks heparan sulfate-degrading activity typical of heparanase. We subjected sections of gastric carcinoma to immunostaining and correlated Hpa2 immunoreactivity with clinical records, including tumor grade, stage and patients' status. We over-expressed Hpa2 in gastric carcinoma cell lines and examined their tumorigenic properties in vitro and in vivo. We also evaluated the expression of Hpa2 by gastric carcinoma cells following inhibition of the proteasome, leading to proteotoxic stress, and the resulting signaling responsible for Hpa2 gene regulation. Here, we report that gastric cancer patients exhibiting high levels of Hpa2 survive longer. Similarly, mice administrated with gastric carcinoma cells engineered to over-express Hpa2 produced smaller tumors and survived longer than mice administrated with control cells. This was associated with increased phosphorylation of AMP-activated protein kinase (AMPK), a kinase that is situated at the center of a tumor suppressor network. We also found that MG132, an inhibitor of the proteasome that results in proteotoxic stress, prominently enhances Hpa2 expression. Notably, Hpa2 induction by MG132 appeared to be mediated by AMPK, and AMPK was found to induce the expression of Hpa2, thus establishing a loop that feeds itself where Hpa2 enhances AMPK phosphorylation that, in turn, induces Hpa2 expression, leading to attenuation of gastric tumorigenesis. These results indicate that high levels of Hpa2 in some tumors are due to stress conditions that tumors often experience due to their high rates of cell proliferation and high metabolic demands. This increase in Hpa2 levels by the stressed tumors appears critically important for patient outcomes.

Heparanase confers temozolomide resistance by regulation of exosome secretion and circular RNA composition in glioma

Temozolomide (TMZ) resistance is the main challenge in the management of glioma patients. Heparanase can mediate the secretion and function of exosomes, which are considered to be a promising molecular delivery system for cancer therapy. Therefore, this study aimed to investigate whether heparanase‐mediated delivery of exosomes was related to TMZ resistance of glioma. Heparanase was upregulated in TMZ‐resistant glioma cells, and overexpression of heparanase led to increased resistance of U87 cells to TMZ. Knockdown of heparanase led to increased sensitivity of TMZ‐resistant U251 cells (U251R) cells to TMZ. Heparanase promoted the secretion of exosomes from glioma cells, and coculture with exosomes derived from heparanase knockdown U251R cells partly restored the sensitivity of U251 cells to TMZ compared with exosomes derived from si‐control transfected U251R cells. It was identified by circular RNA microarrays that hsa_circ_0042003 was upregulated in exosomes derived from U251R, which could be positively regulated by heparanase. U251R cell‐derived exosomal hsa_circ_0042003 conferred the resistance of U251 cells to TMZ. In vivo studies also showed that U251R cell‐derived exosomes induced resistance of U251 cells to TMZ, and the combination of tail‐injected exosomal si‐heparanase or exosomal si‐hsa_circ_0042003 and intraperitoneal TMZ applied to nude mice abolished TMZ resistance. Heparanase mediated the transfer of exosomal hsa_circ_0042003 from TMZ‐resistant glioma cells to drug‐sensitive cells, which contributed to the chemoresistance of glioma to TMZ.

A Signaling View into the Inflammatory Tumor Microenvironment

The development of tumors requires an initiator event, usually exposure to DNA damaging agents that cause genetic alterations such as gene mutations or chromosomal abnormalities, leading to deregulated cell proliferation. Although the mere stochastic accumulation of further mutations may cause tumor progression, it is now clear that an inflammatory microenvironment has a major tumor-promoting influence on initiated cells, in particular when a chronic inflammatory reaction already existed before the initiated tumor cell was formed. Moreover, inflammatory cells become mobilized in response to signals emanating from tumor cells. In both cases, the microenvironment provides signals that initiated tumor cells perceive by membrane receptors and transduce via downstream kinase cascades to modulate multiple cellular processes and respond with changes in cell gene expression, metabolism, and morphology. Cytokines, chemokines, and growth factors are examples of major signals secreted by immune cells, fibroblast, and endothelial cells and mediate an intricate cell-cell crosstalk in an inflammatory microenvironment, which contributes to increased cancer cell survival, phenotypic plasticity and adaptation to surrounding tissue conditions. Eventually, consequent changes in extracellular matrix stiffness and architecture, coupled with additional genetic alterations, further fortify the malignant progression of tumor cells, priming them for invasion and metastasis. Here, we provide an overview of the current knowledge on the composition of the inflammatory tumor microenvironment, with an emphasis on the major signals and signal-transducing events mediating different aspects of stromal cell-tumor cell communication that ultimately lead to malignant progression.

New Heparanase-Inhibiting Triazolo-Thiadiazoles Attenuate Primary Tumor Growth and Metastasis

Simple Summary

Heparanase is an endoglycosidase that plays a critical role in tumor progression and metastasis. The expression of heparanase in the tumor microenvironment is positively correlated with the aggressiveness of the tumor and is associated with poor prognosis. In this study, we have demonstrated that a new triazole–thiadiazole-bearing small molecule showed good heparanase inhibition along with attenuation of tumor growth and metastasis. To the best of our knowledge, this is the first report showing a marked decrease in primary tumor growth in mice treated with a small molecule that inhibits heparanase enzymatic activity. Given these encouraging results, studies are underway to better elucidate the mode of action and clinical significance of triazolo–thiadiazoles.

Abstract

Compelling evidence ties heparanase, an endoglycosidase that cleaves heparan sulfate side (HS) chains of proteoglycans, with all steps of tumor development, including tumor initiation, angiogenesis, growth, metastasis, and chemoresistance. Moreover, heparanase levels correlate with shorter postoperative survival of cancer patients, encouraging the development of heparanase inhibitors as anti-cancer drugs. Heparanase-inhibiting heparin/heparan sulfate-mimicking compounds and neutralizing antibodies are highly effective in animal models of cancer progression, yet none of the compounds reached the stage of approval for clinical use. The present study focused on newly synthesized triazolo–thiadiazoles, of which compound 4-iodo-2-(3-(p-tolyl)-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazol-6-yl)phenol (4-MMI) was identified as a potent inhibitor of heparanase enzymatic activity, cell invasion, experimental metastasis, and tumor growth in mouse models. To the best of our knowledge, this is the first report showing a marked decrease in primary tumor growth in mice treated with small molecules that inhibit heparanase enzymatic activity. This result encourages the optimization of 4-MMI for preclinical and clinical studies primarily in cancer but also other indications (i.e., colitis, pancreatitis, diabetic nephropathy, tissue fibrosis) involving heparanase, including viral infection and COVID-19.

Heparanase: a potential marker of worse prognosis in estrogen receptor-positive breast cancer

Heparanase promotes tumor growth in breast tumors. We now evaluated heparanase protein and gene-expression status and investigated its impact on disease-free survival in order to gain better insight into the role of heparanase in ER-positive (ER+) breast cancer prognosis and to clarify its role in cell survival following chemotherapy. Using pooled analysis of gene-expression data, we found that heparanase was associated with a worse prognosis in estrogen receptor-positive (ER+) tumors (log-rank p < 10-10) and predictive to chemotherapy resistance (interaction p = 0.0001) but not hormonal therapy (Interaction p = 0.62). These results were confirmed by analysis of data from a phase III, prospective randomized trial which showed that heparanase protein expression is associated with increased risk of recurrence in ER+ breast tumors (log-rank p = 0.004). In vitro experiments showed that heparanase promoted tumor progression and increased cell viability via epithelial-mesenchymal transition, stemness, and anti-apoptosis pathways in luminal breast cancer. Taken together, our results demonstrated that heparanase is associated with worse outcomes and increased cell viability in ER+ BC.

Computational Investigation Identified Potential Chemical Scaffolds for Heparanase as Anticancer Therapeutics

Heparanase (Hpse) is an endo-β-D-glucuronidase capable of cleaving heparan sulfate side chains. Its upregulated expression is implicated in tumor growth, metastasis and angiogenesis, thus making it an attractive target in cancer therapeutics. Currently, a few small molecule inhibitors have been reported to inhibit Hpse, with promising oral administration and pharmacokinetic (PK) properties. In the present study, a ligand-based pharmacophore model was generated from a dataset of well-known active small molecule Hpse inhibitors which were observed to display favorable PK properties. The compounds from the InterBioScreen database of natural (69,034) and synthetic (195,469) molecules were first filtered for their drug-likeness and the pharmacophore model was used to screen the drug-like database. The compounds acquired from screening were subjected to molecular docking with Heparanase, where two molecules used in pharmacophore generation were used as reference. From the docking analysis, 33 compounds displayed higher docking scores than the reference and favorable interactions with the catalytic residues. Complex interactions were further evaluated by molecular dynamics simulations to assess their stability over a period of 50 ns. Furthermore, the binding free energies of the 33 compounds revealed 2 natural and 2 synthetic compounds, with better binding affinities than reference molecules, and were, therefore, deemed as hits. The hit compounds presented from this in silico investigation could act as potent Heparanase inhibitors and further serve as lead scaffolds to develop compounds targeting Heparanase upregulation in cancer.

New classes of potent heparanase inhibitors from ligand-based virtual screening

Heparanase is a validated target in cancer therapy and a potential target for several inflammatory pathologies. A ligand-based virtual screening of commercial libraries was performed to expand the chemical space of small-molecule inhibitors. The screening was based on similarity with known inhibitors and was performed in several runs, starting from literature compounds and progressing through newly discovered inhibitors. Among the fifty-five tested compounds, nineteen had IC₅₀ values lower than 5 µM and some showed remarkable potencies. Importantly, tere- and isophthalamides derivatives belong to new structural classes of heparanase inhibitors and some of them showed enzyme affinities (61 and 63, IC₅₀ = 0.32 and 0.12 µM, respectively) similar to those of the most potent small-molecule inhibitors reported so far. Docking studies provided a comprehensive binding hypothesis shared by compounds with significant structural diversity. The most potent inhibitors reduced cell invasiveness and inhibited the expression of proangiogenic factors in tumour cell lines.

Heparanase Inhibitors in Cancer Progression: Recent Advances

BACKGROUND

An endo-β-glucuronidase enzyme, Heparanase (HPSE), degrades the side chains of polymeric heparan sulfate (HS), a glycosaminoglycan formed by alternate repetitive units of D-glucosamine and D-glucuronic acid/L-iduronic acid. HS is a major component of the extracellular matrix and basement membranes and has been implicated in processes of the tissue's integrity and functional state. The degradation of HS by HPSE enzyme leads to conditions like inflammation, angiogenesis, and metastasis. An elevated HPSE expression with a poor prognosis and its multiple roles in tumor growth and metastasis has attracted significant interest for its inhibition as a potential anti-neoplastic target.

METHODS

We reviewed the literature from journal publication websites and electronic databases such as Bentham, Science Direct, PubMed, Scopus, USFDA, etc., about HPSE, its structure, functions, and role in cancer.

RESULTS

The present review is focused on Heparanase inhibitors (HPIns) that have been isolated from natural resources or chemically synthesized as new therapeutics for metastatic tumors and chronic inflammatory diseases in recent years. The recent developments made in the HPSE structure and function are also discussed, which can lead to the future design of HPIns with more potency and specificity for the target.

CONCLUSION

HPIns can be a better target to be explored against various cancers.