Heparanase-induced shedding of syndecan-1/CD138 in myeloma and endothelial cells activates VEGFR2 and an invasive phenotype: prevention by novel synstatins

Zhu

et al. 2017

J Virol

Porcine reproductive and respiratory syndrome virus (PRRSV) continues to cause substantial economic losses to the pig industry worldwide. Heparan sulfate (HS) is used by PRRSV for initial attachment to target cells. However, the role of HS in the late phase of PRRSV infection and the mechanism of virus release from host cells remain largely unknown. In this study, we showed that PRRSV infection caused a decrease in HS expression and upregulated heparanase, the only known enzyme capable of degrading HS. We subsequently demonstrated that the NF-B signaling pathway and cathepsin L protease were involved in regulation of PRRSV infectioninduced heparanase. In addition, we found that ablation of heparanase expression using small interfering RNA duplexes increased cell surface expression of HS and suppressed PRRSV replication and release, whereas overexpression of heparanase reduced HS surface expression and enhanced PRRSV replication and release. These data suggest that PRRSV activates NF-B and cathepsin L to upregulate and process heparanase, and then the active heparanase cleaves HS, resulting in viral release. Our findings provide new insight into the molecular mechanism of PRRSV egress from host cells, which might help us to further understand PRRSV pathogenesis.IMPORTANCE Porcine reproductive and respiratory syndrome virus (PRRSV) causes great economic losses each year to the pig industry worldwide. The molecular mechanism of PRRSV release from host cells largely remains a mystery. In this study, we demonstrate that PRRSV activates NF-B and cathepsin L to upregulate and process heparanase, and then the active heparanase is released to the extracellular space and exerts enzymatic activity to cleave heparan sulfate, resulting in viral release. Our findings provide new insight into the molecular mechanism of PRRSV egress from host cells, which might help us to further understand PRRSV pathogenesis.KEYWORDS PRRSV, heparan sulfate, heparanase, viral release, porcine reproductive and respiratory syndrome virus P orcine reproductive and respiratory syndrome (PRRS) has become one of the most important diseases of intensive pig production worldwide since its emergence in the late 1980s (1, 2). This disease is characterized by respiratory disease, weight loss, and poor growth performance, as well as by late-term abortions (3). The causative agent, PRRS virus (PRRSV), is a small, enveloped, positive-sense, single-stranded RNA virus of the genus Arterivirus, in the family Arteriviridae within the order Nidovirales (4, 5). The PRRSV genome is approximately 15 kb in length and consists of at least 12 overlapping open reading frames (6, 7). Due to the genetic and antigenic differences, PRRSV can be divided into European genotype 1 and North American genotype 2, with Lelystad and VR-2332 as prototypical strains, respectively, which share about 60% nucleotide sequence identity (8). In 2006, highly pathogenic PRRSV (HP-PRRSV)

Section: Discussionmentioning

confidence: 99%

Heparanase Upregulation Contributes to Porcine Reproductive and Respiratory Syndrome Virus Release

Zhu

et al. 2017

J Virol

Molecular Cancer Research

“…HPSE can promote tumor cell invasion in several ways, including actions on HSPGs on the cell surface and in the extracellular matrix (10,26,27,52,53). In multiple myeloma HPSE promotes tumor cell adhesion and invasion via SDC1 ectodomain shedding and subsequent alterations in receptor tyrosine kinase signaling and integrin binding (10,23,54). Few studies have investigated the role for HPSE in primary brain tumors (28–31,46), but the data suggest HPSE can promote tumor growth and progression in vivo.…”

Section: Discussionmentioning

confidence: 99%

“…HSPGs consist of a core protein and covalently attached heparan sulfate (HS) glycosaminoglycan chains comprised of repeating disaccharide units. Extensive co- and post-translational enzymatic modifications, particularly involving the HS chains, generate the structural diversity important for their many functions, including their ability to bind and sequester soluble ligands, act as a co-receptor on the cell surface (9), and influence cell adhesion and migration, one mechanism being the regulation of integrin activity (8,10). …”

Section: Introductionmentioning

confidence: 99%

“…Increased HPSE activity is associated with increased tumorigenesis, angiogenesis and invasiveness in diverse cancers including multiple myeloma, melanoma, breast, and pancreatic cancer (22). In multiple myeloma, a number of oncogenic functions for HPSE have been identified including direct effects on tumor cells and indirect effects on tumor-associated endothelial cells (10,23,23–25). In the brain, HPSE has been implicated in metastatic tumor cell invasion and medulloblastoma cell signaling (26–28), but its role in GBM is less established (29,30) although recent studies suggest its importance in tumor progression (31).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Heparan Sulfate Glycosaminoglycans in Glioblastoma Promote Tumor Invasion

Tran

Wade

McKinney

et al. 2017

Glioblastoma (GBM) is the most common primary malignant brain tumor of adults and confers a poor prognosis due, in part, to diffuse invasion of tumor cells. Heparan sulfate (HS) glycosaminoglycans, present on the cell surface and in the extracellular matrix, regulate cell signaling pathways and cell-microenvironment interactions. In GBM, the expression of HS glycosaminoglycans and the enzymes that regulate their function are altered but the actual HS content and structure are unknown. However, inhibition of HS glycosaminoglycan function is emerging as a promising therapeutic strategy for some cancers. In this study, we use liquid chromatography-mass spectrometry (LC/MS) analysis to demonstrate differences in HS disaccharide content and structure across four patient-derived tumorsphere lines (GBM1, 5, 6, 43) and between two murine tumorsphere lines derived from murine GBM with enrichment of mesenchymal and proneural gene expression (mMES and mPN, respectively) markers. In GBM, the heterogeneous HS content and structure across patient-derived tumorsphere lines suggested diverse functions in the GBM tumor microenvironment (TME). In GBM5 and mPN, elevated expression of sulfatase 2 (SULF2), an extracellular enzyme that alters ligand binding to HS, was associated with low trisulfated HS disaccharides, a substrate of SULF2. In contrast, other primary tumorsphere lines had elevated expression of the HS-modifying enzyme heparanase (HPSE). Using gene editing strategies to inhibit HPSE a role for HPSE in promoting tumor cell adhesion and invasion was identified. These studies characterize the heterogeneity in HS glycosaminoglycan content and structure across GBM and reveal their role in tumor cell invasion.

“…In the hematological malignancy multiple myeloma, data from our lab and others has demonstrated that heparanase drives angiogenesis, tumor growth, and metastasis [6–12], establishing it as a master regulator of aggressive tumor behavior. Soluble heparanase is present in the peripheral blood and plasma from bone marrow aspirates of myeloma patients, and high heparanase activity in the bone marrow strongly correlates with high microvessel density, consistent with the known role of heparanase in angiogenesis [9].…”

Section: Introductionmentioning

confidence: 99%

Chemotherapy induces expression and release of heparanase leading to changes associated with an aggressive tumor phenotype

Ramani

Vlodavsky²,

et al. 2016

Matrix Biology

104

High heparanase expression is associated with enhanced tumor growth, angiogenesis, and metastasis in many types of cancer. However, the mechanisms driving high heparanase expression are not fully understood. In the present study, we discovered that drugs used in the treatment of myeloma upregulate heparanase expression. Frontline anti-myeloma drugs, bortezomib and carfilzomib activate the nuclear factor-kappa B (NF-κB) pathway to trigger heparanase expression in tumor cells. Blocking the NF-κB pathway diminished this chemotherapy-induced upregulation of heparanase expression. Activated NF-κB signaling was also found to drive high heparanase expression in drug resistant myeloma cell lines. In addition to enhancing heparanase expression, chemotherapy also caused release of heparanase by tumor cells into the conditioned medium. This soluble heparanase was taken up by macrophages and triggered an increase in TNF-α production. Heparanase is also taken up by tumor cells where it induced expression of HGF, VEGF and MMP-9 and activated ERK and Akt signaling pathways. These changes induced by heparanase are known to be associated with the promotion of an aggressive tumor phenotype. Importantly, the heparanase inhibitor Roneparstat diminished the uptake and the downstream effects of soluble heparanase. Together, these discoveries reveal a novel mechanism whereby chemotherapy upregulates heparanase, a known promoter of myeloma growth, and suggest that therapeutic targeting of heparanase during anti-cancer therapy may improve patient outcome.