Low molecular weight hyaluronan inhibits colorectal carcinoma growth by decreasing tumor cell proliferation and stimulating immune response

Marine polysaccharides: Biological activities and applications in drug delivery systems

The ocean is the common home of a large number of marine organisms, including plants, animals, and microorganisms. Researchers can extract thousands of important bioactive components from the oceans and use them extensively to treat and prevent diseases. In contrast, marine polysaccharide macromolecules such as alginate, carrageenan, Laminarin, fucoidan, chitosan, and hyaluronic acid have excellent physicochemical properties, good biocompatibility, and high bioactivity, which ensures their wide applications and strong therapeutic potentials in drug delivery. Drug delivery systems (DDS) based on marine polysaccharides and modified marine polysaccharide molecules have emerged as an innovative technology for controlling drug distribution on temporal, spatial, and dosage scales. They can detect and respond to external stimuli such as pH, temperature, and electric fields. These properties have led to their wide application in the design of novel drug delivery systems such as hydrogels, polymeric micelles, liposomes, microneedles, microspheres, etc. In addition, marine polysaccharide-based DDS not only have smart response properties but also can combine with the unique biological properties of the marine polysaccharide base to exert synergistic therapeutic effects. The biological activities of marine polysaccharides and the design of marine polysaccharide-based DDS are reviewed. Marine polysaccharide-based responsive DDS are expected to provide new strategies and solutions for disease treatment.

Exploiting ECM remodelling to promote immune-mediated tumour destruction

Cancer immunotherapy represents a significant breakthrough in cancer treatment mainly due to the ability to harness the activities of cancer-specific T cells. Despite this, most cancers remain resistant to T cell attack. Many reasons have been proposed to explain this, ranging from a lack of antigenicity through to the immunosuppressive effects of the tumour microenvironment. In this review, we examine the relationship between the immune system and a key component of the tumour microenvironment, namely the extracellular matrix (ECM). Specifically, we explore the reciprocal effects of immune cells and the tumour ECM and how the processes underpinning this relationship act to either promote or restrain tumour progression.

Effects of Eye Drops Containing Hyaluronic Acid-Nimesulide Conjugates in a Benzalkonium Chloride-Induced Experimental Dry Eye Rabbit Model

Dry eye syndrome (DES) is a common ocular disease worldwide. Currently, anti-inflammatory agents and immunosuppressive drugs, such as cyclosporine A, have been widely used to treat this chronic condition. However, the multifactorial etiology of DES, poor tolerance, low bioavailability, and prolonged treatment to response time have limited their usage. In this study, nimesulide, a cyclooxygenase (COX)-2 selective inhibitor, was conjugated with hyaluronic acid (HA), and the HA-nimesulide conjugates were expected to increase the solubility and biocompatibility for alleviating the DES in the benzalkonium chloride (BAC)-induced goblet cell-loss dry eye model. The therapeutic efficacy of HA-nimesulide was assessed using fluorescein staining, goblet cell density by conjunctival impression cytology, and histology and immunohistochemistry of corneal tissues. Compared to commercial artificial tears and Restasis®, the HA-nimesulide conjugates could promote goblet cell recovery and enhance the regeneration of the corneal epithelium. Importantly, immunofluorescent staining studies demonstrated that the HA-nimesulide conjugates could decrease the number of infiltrating CD11b-positive cells after two weeks of topical application. In the anti-inflammatory test, the HA-nimesulide conjugates could inhibit the production of pro-inflammatory cytokines and prostaglandin E2 (PGE2) in the lipopolysaccharide (LPS)-stimulated Raw 264.7 cell model. In conclusion, we demonstrated that HA-nimesulide conjugates had anti-inflammatory activity, and promoted goblet cell recovery and corneal epithelium regeneration when used as topical eye drops; accordingly, the HA-nimesulide conjugates could potentially be effective for the treatment of DES.

The action of hyaluronan in functional properties, morphology and expression of matrix effectors in mammary cancer cells depends on its molecular size

Breast cancer constitutes a heterogeneous disease. The expression profiles of estrogen receptors (ERs), as well as the expression patterns of extracellular matrix (ECM) macromolecules, determine its development and progression. Hyaluronan (HA) is an ECM molecule that regulates breast cancer cells' properties in a molecular size-dependent way. Previous studies have shown that 200-kDa HA fragments modulate the functional properties, morphology, and expression of several matrix mediators of the highly metastatic ERα^- /ERβ⁺ MDA-MB-231 cells. In order to evaluate the effects of HA fragments (< 10, 30 and 200-kDa) in ERβ-suppressed breast cancer cells, the shERβ MDA-MB-231 cells were used. These cells are less aggressive when compared with MDA-MB-231 cells. To this end, the functional properties, the morphology, and the expression of the molecules associated with breast cancer cells metastatic potential were studied. Notably, both cell proliferation and invasion were significantly reduced after treatment with 200-kDa HA. Moreover, as assessed by scanning electron microscopy, 200-kDa HA affected cellular morphology, and as assessed by qPCR, upregulated the epithelial marker Ε-cadherin. The expression profiles of ECM mediators, such as HAS2, CD44, and MMP7, were also altered. On the other hand, cellular migration and the expression levels of syndecan-4 (SDC-4) were not significantly affected in contrast to our observations regarding MDA-MB-231 cells. These novel data demonstrate that the molecular size of the HA determines its effects on ERβ-suppressed breast cancer cells and that 200-kDa HA exhibits antiproliferative effects on these cells. A deeper understanding of this mechanism may contribute to the development of therapeutic strategies against breast cancer.

Expression and characterization of a thermotolerant and pH-stable hyaluronate lyase from Thermasporomyces composti DSM22891

Hyaluronate lyases have received extensive attention due to their applications in medical science, drug and biochemical engineering. However, few thermotolerant and pH-stable hyaluronate lyases have been found. In this study, hyaluronate lyase TcHly8B from Thermasporomyces composti DSM22891 was expressed in Escherichia coli BL21(DE3), purified, and characterized. Phylogenetic analysis revealed that TcHly8B belonged to a new subfamily in PL8. The molecular mass of recombinant TcHly8B determined by SDS-PAGE was approximately 86 kDa. The optimal temperature of TcHly8B was 70 °C, which was higher than that of previously reported hyaluronate lyases. TcHly8B was very stable at temperatures from 0 to 60 °C. The optimal pH of TcHly8B was 6.6. It could retain more than 80% of its original enzyme activity after incubation for 12 h in the pH range of 3.0-10.6. TcHly8B degraded hyaluronic acid into unsaturated disaccharides as the end products. The amino acid sequence and structure analysis of TcHly8B demonstrated that the amino acid composition and salt bridges might contribute to the thermostability of TcHly8B. Overall, this study provides an excellent example for the discovery of thermotolerant hyaluronate lyases and can be applied to the industrialized production and basic research of hyaluronate oligosaccharides.

Construction and evaluation of hyaluronic acid-based copolymers as a targeted chemotherapy drug carrier for cancer therapy

Melanoma (MM) is a highly aggressive skin cancer with limited treatment options. Although chemotherapy has been using for advanced melanoma treatment, the lack of targetability, the poor biocompatibility and the severe side effects still hamper the wide applications of chemotherapy agents in MM management. Herein, a biocompatible and biodegradable polymeric hyaluronic acid nanoparticle (HANP) encapsulated with Paclitaxel (PTX) was developed for MM targeted therapy. Our results showed that PTX at 37 ± 2.1% (w/w) was able to be loaded into HANP with over 5 d of stability under physiological conditions. In vitro, HANP/PTX presented hyaluronidase-dependent drug release. Compared to free PTX, HANP/PTX demonstrated a 6-75 times higher growth inhibition in five different cancer cells, while only presenting minimum toxicity to normal cells. After intravenous administration at a 10 mg kg^-1 equivalent dose of PTX, HANP/PTX significantly ablated MM tumor growth in a mouse model. As confirmed by ¹⁸F-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) imaging, the tumors started to respond to the HANP/PTX as early as 7 d after the initial treatment, which will significantly benefit for personalized treatment. In conclusion, the HANP/PTX nanocomplex demonstrated great promise as a translational nanomedicine for cancer chemotherapy.

Anti-CD44 DNA Aptamers Selectively Target Cancer Cells

CD44 is a type I transmembrane glycoprotein interacting with a number of extracellular components, including hyaluronic acid (HA). CD44-HA axis is involved in a variety of processes, including adhesion, migration, differentiation, trafficking, and others. CD44 is overexpressed in several cancers where binding of HA induces signal transduction leading to activation of antiapoptotic proteins and factors linked to drug resistance. As such, CD44 has been implicated in cancer growth, progression, and metastasis. It has been convincingly demonstrated that blocking CD44-HA interaction decreases cancer cell survival and metastasis. In this study, using in vitro selection, we have developed DNA aptamers recognizing a HA-binding domain of CD44 with high affinity and specificity. The aptamers bind to CD44 with nanomolar affinities and efficiently inhibit the growth of leukemic cancer cells characterized by high expression of CD44. The selectivity is demonstrated by an irrelevant effect on cells characterized by low CD44 levels. The obtained aptamers broaden the existing landscape of potential approaches to the development of antitumor strategies based on inhibition of the CD44 axis.

Cellular hyaluronan is associated with a poor prognosis in renal cell carcinoma

PURPOSE

Hyaluronan, a major glycosaminoglycan of the extracellular matrix, can act as an oncogenic component of the tumor microenvironment in many human malignancies. We characterized the hyaluronan content of renal cell carcinomas (RCCs) and investigated its correlations with clinicopathological parameters and patient survival.

PATIENTS AND METHODS

This retrospective study included data from 316 patients that had undergone surgery for RCC in Kuopio University Hospital in 2000 to 2013. The hyaluronan content of surgical tumor samples were histochemically stained with a biotinylated hyaluronan-specific affinity probe. The amount of tumor infiltrating lymphocytes was evaluated in each tumor. Kaplan-Meier and univariate and multivariate Cox-regression analyses were performed to estimate the impact of hyaluronan content on overall survival, disease-specific survival, and metastasis-free survival.

RESULTS

Detectable cellular hyaluronan was associated with higher tumor grades and the presence of tumor infiltrating lymphocytes. Cellular hyaluronan identified a prognostically unfavourable subgroup among low-grade carcinomas. Multivariate analyses showed that measurable cellular hyaluronan was an independent negative prognostic factor for overall survival (hazard ratio [HR] 1.4; 95% confidence interval [CI]: 1.02-2.0; P = 0.039), Disease-specific survival (HR 2.07; 95% CI: 1.2-3.3; P = 0.002), and metastasis-free survival (HR 2.45; 95% CI: 1.37-4.4; P = 0.003).

CONCLUSIONS

Cellular hyaluronan was significantly associated with unfavourable features and a poor prognosis in RCC. Further studies are needed to investigate the biological mechanism underlying hyaluronan accumulation in RCC.

Hyaluronan in the Tumor Microenvironment

The extracellular matrix is part of the microenvironment and its functions are associated with the physical and chemical properties of the tissue. Among the extracellular components, the glycosaminoglycan hyaluronan is a key component, defining both the physical and biochemical characteristics of the healthy matrices. The hyaluronan metabolism is strictly regulated in physiological conditions, but in the tumoral tissues, its expression, size and binding proteins interaction are dysregulated. Hyaluronan from the tumor microenvironment promotes tumor cell proliferation, invasion, immune evasion, stemness alterations as well as drug resistance. This chapter describes data regarding novel concepts of hyaluronan functions in the tumor. Additionally, we discuss potential clinical applications of targeting HA metabolism in cancer therapy.

Molecular size-dependent specificity of hyaluronan on functional properties, morphology and matrix composition of mammary cancer cells

High levels of hyaluronan (ΗΑ), a major extracellular matrix (ECM) glycosaminoglycan, have been correlated with poor clinical outcome in several malignancies, including breast cancer. The high and low molecular weight HΑ forms exert diverse biological functions. Depending on their molecular size, ΗΑ forms either promote or attenuate signaling cascades that regulate cancer progression. In order to evaluate the effects of different ΗΑ forms on breast cancer cells' behavior, ΗΑ fragments of defined molecular size were synthesized. Breast cancer cells of different estrogen receptor (ER) status - the low metastatic, ERα-positive MCF-7 epithelial cells and the highly aggressive, ERβ-positive MDA-MB-231 mesenchymal cells - were evaluated following treatment with HA fragments. Scanning electron microscopy revealed that HA fragments critically affect the morphology of breast cancer cells in a molecular-size dependent mode. Moreover, the ΗΑ fragments affect cell functional properties, the expression of major ECM mediators and epithelial-to-mesenchymal transition (ΕΜΤ) markers. Notably, treatment with 200 kDa ΗΑ increased the expression levels of the epithelial marker Ε-cadherin and reduced the expression levels of HA synthase 2 and mesenchymal markers, like fibronectin and snail2/slug. These novel data suggest that the effects of HA in breast cancer cells depend on the molecular size and the ER status. An in-depth understanding on the mechanistic basis of these effects may contribute on the development of novel therapeutic strategies for the pharmacological targeting of aggressive breast cancer.

The CD147-HYALURONAN Axis in Cancer

CD147 (basigin; EMMPRIN), hyaluronan, and hyaluronan receptors (e.g., CD44) are intimately involved in several phenomena that underlie malignancy. A major avenue whereby they influence tumor progression is most likely their role in the characteristics of cancer stem cells (CSCs), subpopulations of tumor cells that exhibit chemoresistance, invasiveness, and potent tumorigenicity. Both CD147 and hyaluronan have been strongly implicated in chemoresistance and invasiveness, and may be drivers of CSC characteristics, since current evidence indicates that both are involved in epithelial-mesenchymal transition, a crucial process in the acquisition of CSC properties. Hyaluronan is a prominent constituent of the tumor microenvironment whose interactions with cell surface receptors influence several signaling pathways that lead to chemoresistance and invasiveness. CD147 is an integral plasma membrane glycoprotein of the Ig superfamily and cofactor in assembly and activity of monocarboxylate transporters (MCTs). CD147 stimulates hyaluronan synthesis and interaction of hyaluronan with its receptors, in particular CD44 and LYVE-1, which in turn result in activation of multiprotein complexes containing members of the membrane-type matrix metalloproteinase, receptor tyrosine kinase, ABC drug transporter, or MCT families within lipid raft domains. Multivalent hyaluronan-receptor interactions are essential for formation or stabilization of these lipid raft complexes and for downstream signaling pathways or transporter activities. We conclude that stimulation of hyaluronan-receptor interactions by CD147 and the consequent activities of these complexes may be critical to the properties of CSCs and their role in malignancy. Anat Rec, 2019. © 2019 Wiley Periodicals, Inc.

Hyaluronan: molecular size-dependent signaling and biological functions in inflammation and cancer

Hyaluronan (HA) is a linear nonsulfated glycosaminoglycan of the extracellular matrix that plays a pivotal role in a variety of biological processes. High-molecular weight HA exhibits different biological properties than oligomers and low-molecular weight HA. Depending on their molecular size, HA fragments can influence cellular behavior in a different mode of action. This phenomenon is attributed to the different manner of interaction with the HA receptors, especially CD44 and RHAMM. Both receptors can trigger signaling cascades that regulate cell functional properties, such as proliferation migration, angiogenesis, and wound healing. HA fragments are able to enhance or attenuate the HA receptor-mediated signaling pathways, as they compete with the endogenous HA for binding to the receptors. The modulation of these pathways could be crucial for the development of pathological conditions, such as inflammation and cancer. The primary goal of this review is to critically present the importance of HA molecular size on cellular signaling, functional cell properties, and morphology in normal and pathological conditions, including inflammation and cancer. A deeper understanding of these mechanisms could contribute to the development of novel therapeutic strategies.

Co-treatment of tumor cells with hyaluronan plus doxorubicin affects endothelial cell behavior independently of VEGF expression

Hyaluronan, the main glycosaminoglycan of extracellular matrices, is concentrated in tissues with high cell proliferation and migration rates. In cancer, hyaluronan expression is altered and it becomes fragmented into low-molecular-weight forms, affecting mechanisms associated with cell proliferation, invasion, angiogenesis and multidrug resistance. Here, we analyzed the effect of low-molecular-weight hyaluronan on the response of T lymphoma, osteosarcoma, and mammary adenocarcinoma cell lines to the antineoplastic drug doxorubicin, and whether co-treatment with hyaluronan and doxorubicin modified the behavior of endothelial cells. Our aim was to associate the hyaluronan-doxorubicin response with angiogenic alterations in these tumors. After hyaluronan and doxorubicin co-treatment, hyaluronan altered drug accumulation and modulated the expression of ATP-binding cassette transporters in T-cell lymphoma cells. In contrast, no changes in drug accumulation were observed in cells from solid tumors, indicating that hyaluronan might not affect drug efflux. However, when we evaluated the effect on angiogenic mechanisms, the supernatant from tumor cells treated with doxorubicin exhibited a pro-angiogenic effect on endothelial cells. Hyaluronan-doxorubicin co-treatment increased migration and vessel formation in endothelial cells. This effect was independent of vascular endothelial growth factor but related to fibroblast growth factor-2 expression. Besides, we observed a pro-angiogenic effect on endothelial cells during hyaluronan and doxorubicin co-treatment in the in vivo murine model of T-cell lymphoma. Our results demonstrate for the first time that hyaluronan is a potential modulator of doxorubicin response by mechanisms that involve not only drug efflux but also angiogenic processes, providing an adverse tumor stroma during chemotherapy.

Tumor matrix remodeling and novel immunotherapies: the promise of matrix-derived immune biomarkers

Recent advances in our understanding of the dynamics of cellular cross-talk have highlighted the significance of host-versus-tumor effect that can be harnessed with immune therapies. Tumors exploit immune checkpoints to evade adaptive immune responses. Cancer immunotherapy has witnessed a revolution in the past decade with the development of immune checkpoint inhibitors (ICIs), monoclonal antibodies against cytotoxic T lymphocyte antigen 4 (CTLA-4) and programmed cell death protein 1 (PD-1) or their ligands, such as PD1 ligand 1 (PD-L1). ICIs have been reported to have activity against a broad range of tumor types, in both solid organ and hematologic malignancy contexts. However, less than one-third of the patients achieve a durable and meaningful treatment response. Expression of immune checkpoint ligands (e.g., PD-L1), mutational burden and tumor-infiltrating lymphocytes are currently used as biomarkers for predicting response to ICIs. However, they do not reliably predict which patients will benefit from these therapies. There is dire need to discover novel biomarkers to predict treatment efficacy and to identify areas for development of combination strategies to improve response rates. Emerging evidence suggests key roles of tumor extracellular matrix (ECM) components and their proteolytic remodeling products in regulating each step of the cancer-immunity cycle. Here we review tumor matrix dynamics and matrix remodeling in context of anti-tumor immune responses and immunotherapy and propose the exploration of matrix-based biomarkers to identify candidates for immune therapy.

A Trickster in Disguise: Hyaluronan's Ambivalent Roles in the Matrix

Hyaluronan (HA) is a simple but diverse glycosaminoglycan. It plays a major role in aging, cellular senescence, cancer, and tissue homeostasis. In which way HA affects the surrounding tissues greatly depends on the molecular weight of HA. Whereas high molecular weight HA is associated with homeostasis and protective effects, HA fragments tend to be linked to the pathologic state. Furthermore, the interaction of HA with its binding partners, the hyaladherins, such as CD44, is essential for sustaining tissue integrity and is likewise related to cancer. The naked mole rat, a rodent species, possesses a special form of very high molecular weight (vHMW) HA, which is associated with the extraordinary cancer resistance and longevity of those animals. This review addresses HA and its diverse facets: from HA synthesis to degradation, from oligomeric HA to vHMW-HA and from its beneficial properties to the involvement in pathologies. We further discuss the functions of HA in the naked mole rat and compare them to human conditions. Though intensively researched, this simple polymer bears some secrets that may hold the key for a better understanding of cellular processes and the development of diseases, such as cancer.

Hydrogels bearing bioengineered mimetic embryonic microenvironments for tumor reversion

Embryonic microenvironments can reverse the metastatic phenotype of aggressive tumors by inhibiting the Nodal signaling pathway. Here, we hypothesize that embryonic microenvironments can be transplanted for the purpose of oncotherapy. We report the development of an injectable bioactive hydrogel system containing the key antagonists of Nodal signaling-Cripto-1 receptor antibodies (2B11)-for the creation of embryonic microenvironments and the examination of their effect on tumor reversion treatment using a mouse model. Our in vitro results show that the hydrogel system can reduce the mitochondrial membrane potential of MDA-MB-231 and MCF-7, promote cell apoptosis, and reduce the invasive ability of cells. Our in vivo results illustrate that the hydrogel system can significantly inhibit tumor growth in both breast cancer and melanoma tumor-bearing mouse models, as well as transform the cell morphology of melanoma B16 cells to melanin-like cells. Furthermore, the results of the up-regulation of tumor suppressor genes and the down-regulation of oncogenes by high-throughput sequencing confirm that the developed system can also selectively turn on some tumor suppressor genes and turn off certain oncogenes so as to prompt the benign reversion of the tumor phenotype. Taken together, our results demonstrate the injectable biomaterial system is able to create an effective microenvironment for melanoma and breast tumor therapy.

Esophageal Squamous Cell Carcinoma Cells Modulate Chemokine Expression and Hyaluronan Synthesis in Fibroblasts

The aim of this study was to characterize the interaction of KYSE-410, an esophageal squamous cell carcinoma cell line, and fibroblasts with respect to the extracellular matrix component hyaluronan (HA) and chemokine expression. KYSE-410 cells induced the mRNA expression of HA synthase 2 (Has2) in normal skin fibroblasts (SF) only in direct co-cultures. Parallel to Has2 mRNA, Has2 antisense RNA (Has2os2) was up-regulated in co-cultures. Knockdown of LEF1, a downstream target of Wnt signaling, abrogated Has2 and Has2os2 induction. After knockdown of Has2 in SF, significantly less α-smooth muscle actin expression was detected in co-cultures. Moreover, it was investigated whether the phenotype of KYSE-410 was affected in co-culture with SF and whether Has2 knockdown in SF had an impact on KYSE-410 cells in co-culture. However, no effects on epithelial-mesenchymal transition markers, proliferation, and migration were detected. In addition to Has2 mRNA, the chemokine CCL5 was up-regulated and CCL11 was down-regulated in SF in co-culture. Furthermore, co-cultures of KYSE-410 cells and cancer-associated fibroblasts (CAF) were investigated. Similar to SF, Has2 and Ccl5 were up-regulated and Ccl11 was down-regulated in CAF in co-culture. Importantly and in contrast to SF, inhibiting HA synthesis by 4-methylumbelliferone abrogated the effect of co-culture on Ccl5 in CAF. Moreover, HA was found to promote adhesion of CD4(+) but not CD8(+) cells to xenogaft tumor tissues. In conclusion, direct co-culture of esophageal squamous cell carcinoma and fibroblasts induced stromal HA synthesis via Wnt/LEF1 and altered the chemokine profile of stromal fibroblasts, which in turn may affect the tumor immune response.

The immunological effect of hyaluronan in tumor angiogenesis

The relationship between the immune system and angiogenesis has been described in several contexts, both in physiological and pathological conditions, as pregnancy and cancer. In fact, different types of immune cells, such as myeloid, macrophages and denditric cells, are able to modulate tumor neovascularization. On the other hand, tumor microenvironment also includes extracellular matrix components like hyaluronan, which has a deregulated synthesis in different tumors. Hyaluronan is a glycosaminoglycan, normally present in the extracellular matrix of tissues in continuous remodeling (embryogenesis or wound healing processes) and acts as an important modulator of cell behavior by different mechanisms, including angiogenesis. In this review, we discuss hyaluronan as a modulator of tumor angiogenesis, focusing in intracellular signaling mediated by its receptors expressed on different immune cells. Recent observations suggest that the immune system is an important component in tumoural angiogenesis. Therefore, immune modulation could have an impact in anti-angiogenic therapy as a new therapeutic strategy, which in turn might improve effectiveness of treatment in cancer patients.

Sugars in the microenvironment: the sticky problem of HA turnover in tumors

The properties and behavior of tumor cells are closely regulated by their microenvironment. Accordingly, stromal cells and extracellular matrix components can have a pronounced effect on cancer initiation, growth, and progression. The linear glycosaminoglycan hyaluronan (HA) is a major component of the extracellular matrix. Altered synthesis and degradation of HA in the tumor context has been implicated in many aspects of tumor biology. In particular, the accumulation of small HA oligosaccharides (sHA) in the tumor interstitial space may play a decisive role, due to the ability of sHA to activate a number of biological processes that are not modulated by high molecular weight (HMW)-HA. In this article, we review the normal physiological role and metabolism of HA and then survey the evidence implicating HA in tumor growth and progression, focusing in particular on the potential contribution of sHA to these processes.

Hyaluronan - a functional and structural sweet spot in the tissue microenvironment

Transition from homeostatic to reactive matrix remodeling is a fundamental adaptive tissue response to injury, inflammatory disease, fibrosis, and cancer. Alterations in architecture, physical properties, and matrix composition result in changes in biomechanical and biochemical cellular signaling. The dynamics of pericellular and extracellular matrices, including matrix protein, proteoglycan, and glycosaminoglycan modification are continually emerging as essential regulatory mechanisms underlying cellular and tissue function. Nevertheless, the impact of matrix organization on inflammation and immunity in particular and the consequent effects on tissue healing and disease outcome are arguably under-studied aspects of adaptive stress responses. Herein, we review how the predominant glycosaminoglycan hyaluronan (HA) contributes to the structure and function of the tissue microenvironment. Specifically, we examine the evidence of HA degradation and the generation of biologically active smaller HA fragments in pathological settings in vivo. We discuss how HA fragments versus nascent HA via alternate receptor-mediated signaling influence inflammatory cell recruitment and differentiation, resident cell activation, as well as tumor growth, survival, and metastasis. Finally, we discuss how HA fragmentation impacts restoration of normal tissue function and pathological outcomes in disease.

Cancer microenvironment and inflammation: role of hyaluronan

The role of inflammation in the development of cancer was described as early as the nineteenth century. Abundant evidence supports the preposition that various cancers are triggered by infection and chronic inflammatory disease whereas, evading immune destruction has been proposed as one of the new “hallmarks of cancer.” Changes of the tumor microenvironment have been closely correlated to cancer-mediated inflammation. Hyaluronan (HA), an important extracellular matrices component, has become recognized as an active participant in inflammatory, angiogenic, fibrotic, and cancer promoting processes. This review discusses how HA and specific HA-binding proteins participate in and regulate cancer-related inflammatory processes.

Tunable aggregation by competing biomolecular interactions

Measurements and models are reported for Concanavalin A (ConA) mediated aggregation of dextran coated colloids that is tunable via a competing ConA-glucose interaction. Video and confocal scanning laser microscopy were used to characterize ConA adsorption to dextran colloids and quasi-2D dextran coated colloid aggregation kinetics vs [ConA] and [glucose]. ConA adsorption to, and aggregation rates of, dextran coated colloids increased from negligible values to high coverage and rapid rates for increasing [ConA] in the range 0.1-10 mM and decreasing [glucose] in the range 1-100 mM, consistent with dissociation constant estimates. Analysis of colloidal aggregation kinetics indicates ConA bridge formation is the rate-limiting step controlling the transition from slow to rapid aggregation. Our findings reveal a mechanism for tuning colloidal interactions and aggregation kinetics through specific, competitive biomolecular interactions, which lends insights into aggregation phenomena in mixed synthetic-biomaterial and biological systems.

Single low-dose cyclophosphamide combined with interleukin-12 gene therapy is superior to a metronomic schedule in inducing immunity against colorectal carcinoma in mice

The use of conventional cytotoxic agents at metronomic schedules, alone or in combination with targeted agents or immunotherapy, is being explored as a promising anticancer strategy. We previously reported a potent antitumor effect of a single low-dose cyclophosphamide and interleukin-12 (IL-12) gene therapy against advanced gastrointestinal carcinoma, in mice. Here, we assessed whether the delivery of IL-12 by gene therapy together with metronomic cyclophosphamide exerts antitumor effects in a murine model of colorectal carcinoma. This combination therapy was able, at least in part, to reverse immunosuppression, by decreasing the number of regulatory T cells (Tregs) as well as of splenic myeloid-derived suppressor cells (MDSCs). However, metronomic cyclophosphamide plus IL-12 gene therapy failed to increase the number of tumor-infiltrating T lymphocytes and, more importantly, to induce a specific antitumor immune response. With respect to this, cyclophosphamide at a single low dose displayed a superior anticancer profile than the same drug given at a metronomic schedule. Our results may have important implications in the design of new therapeutic strategies against colorectal carcinoma using cyclophosphamide in combination with immunotherapy.

Determination of the presence of hyaluronic acid in preparations containing amino acids: the molecular weight characterization

Several pharmaceutical preparations contain hyaluronic acid in the presence of a large variety of low molecular weight charged molecules like amino acids. In these mixtures, it is particularly difficult to determine the concentration and the molecular weight of the hyaluronic acid fragments. In fact zwitterionic compounds in high concentration behave by masking the hyaluronic acid due to the electrostatic interactions between amino acids and hyaluronic acid. In such conditions the common colorimetric test of the hyaluronic acid determination appears ineffective and in the (1)H NMR spectra the peaks of the polymer disappear completely. By a simple separation procedure the presence of hyaluronic acid was revealed by the DMAB test and (1)H NMR while its average molecular weight in the final product was determined by DOSY NMR spectroscopy alone. The latter determination is very important due to the healthy effects of some sizes of this polymer's fragments.

Biomaterials for nanoparticle vaccine delivery systems

Subunit vaccination benefits from improved safety over attenuated or inactivated vaccines, but their limited capability to elicit long-lasting, concerted cellular and humoral immune responses is a major challenge. Recent studies have demonstrated that antigen delivery via nanoparticle formulations can significantly improve immunogenicity of vaccines due to either intrinsic immunostimulatory properties of the materials or by co-entrapment of molecular adjuvants such as Toll-like receptor agonists. These studies have collectively shown that nanoparticles designed to mimic biophysical and biochemical cues of pathogens offer new exciting opportunities to enhance activation of innate immunity and elicit potent cellular and humoral immune responses with minimal cytotoxicity. In this review, we present key research advances that were made within the last 5 years in the field of nanoparticle vaccine delivery systems. In particular, we focus on the impact of biomaterials composition, size, and surface charge of nanoparticles on modulation of particle biodistribution, delivery of antigens and immunostimulatory molecules, trafficking and targeting of antigen presenting cells, and overall immune responses in systemic and mucosal tissues. This review describes recent progresses in the design of nanoparticle vaccine delivery carriers, including liposomes, lipid-based particles, micelles and nanostructures composed of natural or synthetic polymers, and lipid-polymer hybrid nanoparticles.

Stimulation of TLR4 by LMW-HA induces metastasis in human papillary thyroid carcinoma through CXCR7

In inflammatory sites, high molecular weight hyaluronan fragments are degraded into lower molecular weight hyaluronan fragments (LMW-HA) to regulate immune responses. However, the function of LMW-HA in PTC progression remains to be elucidated. In this study, we found that receptor of LMW-HA, TLR4, was aberrantly overexpressed in PTC tissues and cell line W3. Exposure of W3 cells to LMW-HA promoted cell proliferation and migration via TLR4. Knockdown of TLR4 has provided evidence that TLR4 is essential for LMW-HA-induced CXCR7 expression, which is responsible for LMW-HA-induced proliferation and migration of W3 cells. In tumor-bearing adult nude mice, stimulation of LMW-HA on W3 cells promotes CXCR7 expression in tumor masses (P = 0.002) and tumor growth (P < 0.001). To further confirm our findings, we investigated the clinicopathologic significance of TLR4 and CXCR7 expression using immumohistochemistry in 135 human PTC tissues and 56 normal thyroid tissue samples. Higher rates of TLR4 (53%) and CXCR7 (24%) expression were found in PTC tissues than in normal tissues. Expression of TLR4 or CXCR7 is associated with tumor size and lymph node metastasis. Therefore, LMW-HA may contribute to the development of PTC via TLR4/CXCR7 pathway, which may be a novel target for PTC immunomodulatory therapy.

Dendritic cells regulate angiogenesis associated with liver fibrogenesis

During liver fibrogenesis the immune response and angiogenesis process are fine-tuned resulting in activation of hepatic stellate cells that produce an excess of extracellular matrix proteins. Dendritic cells (DC) play a central role modulating the liver immunity and have recently been implicated to favour fibrosis regression; although their ability to influence the development of fibrogenesis is unknown. Therefore, we explored whether the depletion of DC during early stages of liver injury has an impact in the development of fibrogenesis. Using the CD11c.DTR transgenic mice, DC were depleted in two experimental models of fibrosis in vivo. The effect of anti-angiogenic therapy was tested during early stages of liver fibrogenesis. DC depletion accelerates the development of fibrosis and as a consequence, the angiogenesis process is boosted. We observed up-regulation of pro-angiogenic factors together with an enhanced vascular endothelial growth factor (VEGF) bioavailability, mainly evidenced by the decrease of anti-angiogenic VEGF receptor 1 (also known as sFlt-1) levels. Interestingly, fibrogenesis process enhanced the expression of Flt-1 on hepatic DC and administration of sFlt-1 was sufficient to abrogate the acceleration of fibrogenesis upon DC depletion. Thus, DC emerge as novel players during the development of liver fibrosis regulating the angiogenesis process and thereby influencing fibrogenesis.

Different molecular weight hyaluronic acid effects on human macrophage interleukin 1β production

This study examined the effect of hyaluronan (HA) molecular weight on immune response. HA with molecular weights ranging from the unitary disaccharide unit (400 Da) up to 1.7 × 10(6) Da and with very low endotoxin contamination level (less than 0.03 EU/mg) was used. Primary human monocyte/macrophage cultures were assayed for IL-1β production under a variety of inflammatory conditions with or without HA. Under the highest inflammatory states, production of interleukin 1β (IL-1β) was suppressed in the presence of high molecular weight hyaluronan (HMW-HA) and in the presence of low molecular weight hyaluronan (LMW-HA) at mg/mL concentrations. There was variability in the sensitivity of the response to HA fragments with MW below 5000 Da at micromolar concentrations. There was variability in IL-1β cytokine productions from donor to donor in unstimulated human cell cultures. This study supplements our previous published study that investigated the immunogenic effect of HA molecular weights using murine cell line RAW264.6, rat splenocytes, and rat adherent differentiated primary macrophages. These data support the hypothesis that if the amount of endotoxin is reduced to an extremely low level, LMW-HA may not directly provoke normal tissue macrophage-mediated inflammatory reactions.

Inhibition of hyaluronan synthase-3 decreases subcutaneous colon cancer growth by increasing apoptosis

Hyaluronan (HA) and hyaluronan synthases (HAS) have been implicated in cancer growth and progression. We previously have shown that HAS3 and HA mediate tumor growth in SW620 colon cancer cells, but the mechanism remains poorly understood. In addition, the effect of HAS3 inhibition on tumor growth with other cells lines has not been explored. We therefore hypothesized that inhibition of HAS3 in highly tumorigenic HCT116 colon cancer cells would decrease tumor growth and that the underlying mechanism would involve altering proliferation and/or apoptosis. HAS3 expression was inhibited by transfection with siRNA; a scrambled sequence served as a control. Stable transfectants were injected into the flanks of nude mice and tumor growth followed for 30 days. Proliferation and apoptosis were then assessed in the harvested tumors. Results were compared using the Students' t-test and ANOVA where appropriate. siRNA transfection decreased HAS3 expression, protein production, and pericellular HA retention, and decreased in vivo tumor growth. Proliferation was unaffected in the HCT116 tumors, but increased slightly in the SW620 tumors. In contrast, HAS3 inhibition significantly increased apoptosis in all tumors. HAS3 inhibition decreases subcutaneous tumor growth by colon cancer cells and significantly increases apoptosis with less effect on proliferation. These data show that HAS3 and HA mediate colon cancer growth by inhibiting apoptosis.

Glycosaminoglycans and neuroprotection

Glycosaminoglycans (GAGs) are basic building blocks of the ground substance of the extracellular matrix and present at the cellular level as an important component of the glycocalyx covering the cell membrane. In addition to the general role of GAGs in maintaining the integrity of the cell and extracellular matrix by retaining water, certain GAGs exhibit anticoagulant and neuroprotective properties and serve as cell-surface receptors for various molecules. Although heparin, a highly sulfated GAG, has been used as a drug for more than 70 years due to its anticoagulant attributes, the neuroprotective properties of GAGs came into focus only in recent years. The discovery of some of the roles GAGs play in the pathomechanism of numerous neurodegenerative disorders as well as shedding light on the neuroprotective properties of these compounds in animal studies raised the possibility that GAGs may provide an entirely new avenue in the treatment of neurodegenerative diseases. Indeed, some GAGs were successfully used to improve the cognitive function of patients with various neurodegenerative conditions (Ban et al. (1991, 1992); Conti et al. (1989a, b); Passeri and Cucinotta, (1989); Santini (1989). Although the mechanism by which the GAGs exhibit neuroprotective properties is not entirely clear, there is a general consensus that the major factors of the neuroprotective attributes of GAGs include the impact of GAGs on amyloidogenesis and the regulatory action of GAGs in the apoptotic pathway.

Increased hyaluronan levels and decreased dendritic cell activation are associated with tumor invasion in murine lymphoma cell lines

Hyaluronan (HA), a component of the extracellular matrix surrounding tumors, modulates tumor progression and the immune response. Dendritic cells (DC) may tolerize or stimulate immunity against cancer. In this report, we study the association between tumor progression, HA levels and DC activation in a lymphoma model. Mice injected with the cells with highest invasive capacity (LBR-) presented increased HA in serum and lymph nodes, and decreased DC activation in infiltrated lymph nodes and liver. These findings could be related to lack of an effective antitumor immune response and suggest that serum HA levels could have a prognostic value in hematological malignancies.

Low molecular weight hyaluronan preconditioning of tumor-pulsed dendritic cells increases their migratory ability and induces immunity against murine colorectal carcinoma

We have recently shown that systemic administration of low molecular weight hyaluronan (LMW HA) significantly reduces colorectal carcinoma (CRC) growth in vivo. The elicited response is partially mediated by activated dendritic cells (DC). To potentiate the ability of DC loaded with whole tumor lysate (DC/TL) to induce immunity against CRC in mice, we aimed to study the effects of preconditioning DC with LMW HA for therapeutic vaccination. LMW HA improved maturation of ex vivo generated DC, increased IL-12, decreased IL-10 production, and enhanced a MLR activity in vitro. Although TNF-α showed a similar capacity to mature DC, preconditioning of DC/TL with LMW HA increased their ability to migrate in vitro toward CCL19 and CCL-21 in a CD44- and a TLR4-independent manner; this effect was superior to Poly(I:C), LPS, or TNF-α and partially associated with an increase in the expression of CCR7. Importantly, LMW HA dramatically enhanced the in vivo DC recruitment to tumor-regional lymph nodes. When these LMW HA-treated CRC tumor lysate-pulsed DC (DC/TL/LMW HA) were administered to tumor-bearing mice, a potent antitumor response was observed when compared to DC pulsed with tumor lysate alone and matured with TNF-α. Then, we showed that splenocytes isolated from animals treated with DC/TL/LMW HA presented a higher proliferative capacity, increased IFN-γ production, and secreted lower levels of the immunosuppressive IL-10. Besides, increased specific CTL response was observed in DC/TL/LMW HA-treated animals and induced long-term protection against tumor recurrence. Our data show that LMW HA is superior to other agents at inducing DC migration; therefore, LMW HA could be considered a new adjuvant candidate in the preparation of DC-based anticancer vaccines with potent immunostimulatory properties.

Reversal of gastrointestinal carcinoma-induced immunosuppression and induction of antitumoural immunity by a combination of cyclophosphamide and gene transfer of IL-12

Immunotherapy-based strategies for gastrointestinal carcinomas (GIC) have been exploited so far, but these approaches have to face strong mechanisms of immune escape induced by tumours. We previously demonstrated that sub-therapeutic doses of an adenovirus expressing IL-12 genes (AdIL-12) mediated a potent antitumour effect against subcutaneous (s.c.) colorectal carcinomas (CRC) in mice pre-treated with low doses of cyclophosphamide (Cy). In our study we used this combination to assess its impact on the immunosuppressive microenvironment. In s.c. CRC model we demonstrated that non-responder mice failed to decrease Tregs in tumour, spleen and peripheral blood. Reconstitution of Tregs into tumour-bearing mice treated with combined therapy abolished the antitumoural effect. In addition, Cy + AdIL-12 modified Tregs functionality by inhibiting the in vitro secretion of IL-10 and TGF-β and their ability to inhibit dendritic cells activation. Combined treatment decreased the number of myeloid-derived suppressor cells (MDSCs) in comparison to non-treated mice and, interestingly, administration of Tregs restored splenic MDSCs population. Furthermore, combined therapy potently generated specific cytotoxic IFN-γ-secreting CD4+ T cells able to eradicate established CRC tumours after adoptive transfer. Finally, we evaluated the combination on disseminated CRC and pancreatic carcinoma (PC). Cy + AdIL-12 were able to eradicate liver metastatic CRC (47%) and PC tumour nodules (40%) and to prolong animal survival. The results of this study support the hypothesis that Cy + AdIL-12 might be a valid immunotherapeutic strategy for advanced GIC.

Role of versican, hyaluronan and CD44 in ovarian cancer metastasis

There is increasing evidence to suggest that extracellular matrix (ECM) components play an active role in tumor progression and are an important determinant for the growth and progression of solid tumors. Tumor cells interfere with the normal programming of ECM biosynthesis and can extensively modify the structure and composition of the matrix. In ovarian cancer alterations in the extracellular environment are critical for tumor initiation and progression and intra-peritoneal dissemination. ECM molecules including versican and hyaluronan (HA) which interacts with the HA receptor, CD44, have been shown to play critical roles in ovarian cancer metastasis. This review focuses on versican, HA, and CD44 and their potential as therapeutic targets for ovarian cancer.

Combinatorial selection of DNA thioaptamers targeted to the HA binding domain of human CD44

CD44, the primary receptor for hyaluronic acid, plays an important role in tumor growth and metastasis. CD44-hyaluronic acid interactions can be exploited for targeted delivery of anticancer agents specifically to cancer cells. Although various splicing variants of CD44 are expressed on the plasma membrane of cancer cells, the hyaluronic acid binding domain (HABD) is highly conserved among the CD44 splicing variants. Using a novel two-step process, we have identified monothiophosphate-modified aptamers (thioaptamers) that specifically bind to the CD44's HABD with high affinities. Binding affinities of the selected thioaptamers for the HABD were in the range of 180-295 nM, an affinity significantly higher than that of hyaluronic acid (K(d) above the micromolar range). The selected thioaptamers bound to CD44 positive human ovarian cancer cell lines (SKOV3, IGROV, and A2780) but failed to bind the CD44 negative NIH3T3 cell line. Our results indicated that thio substitution at specific positions of the DNA phosphate backbone results in specific and high-affinity binding of thioaptamers to CD44. The selected thioaptamers will be of great interest for further development as a targeting or imaging agent for the delivery of therapeutic payloads for cancer tissues.

Hyaluronan (HA) content, the ratio of HA fragments and the expression of CD44 in the ovine cervix vary with the stage of the oestrous cycle

The complex anatomy of the ovine cervix limits the success of trans-cervical artificial insemination in sheep. However, there is a degree of natural relaxation of cervix at oestrus that is accompanied by an increase in the water content. As hyaluronan (HA) has a high affinity for water molecules, in this study, we tested the hypothesis that the HA content of the cervix, the proportion of different size fragments of HA and expression of its receptor CD44 vary with the stage of the oestrous cycle. Oestrous was synchronized in 25 Welsh mountain ewes, and their cervices were collected either during luteal phase (n=8) or pre-LH (n=8) or post-LH (n=9) surge stage of the oestrous cycle. The pre-LH surge group had the highest HA content (2.96 ng/mg of cervical tissue), which was significantly (P≤0.05) higher than that observed for the post-LH surge (2.04 ng/mg) group. The luteal phase group had a mean HA content intermediate between the pre- and post-LH surge groups, and was significantly different from either. The frequency of cervical samples containing both sizes of HA fragments (small and large) was significantly higher (P≤0.05) in the pre-LH surge group compared with the luteal and the post-LH surge groups, whereas that in post-LH surge group was significantly (P≤0.05) higher than that in the luteal group. The number of cervical samples that contained only small HA fragments was significantly (P≤0.05) higher in the luteal group compared with both the pre- and post-LH surge groups, whereas the number of samples containing only large HA fragments was significantly (P≤0.05) higher in the post-LH surge group compared with the luteal or pre-LH surge groups. Overall mean expression of CD44 in the vaginal and mid regions was significantly (P≤0.001) higher than that in the uterine region, with no difference between the vaginal and mid regions of the cervix. Pattern of CD44 expression depended on the stage of the oestrous cycle. At the luteal stage, CD44 expression did not vary among epithelial, sub-epithelial, circular and longitudinal smooth muscle layers, whereas at the pre- and post-LH surge stages, the expression in the epithelial layer was significantly (P≤0.001) higher than that in the other three layers. In general, CD44 expression in the transverse smooth muscle layer was significantly (P≤0.05) lower than the expression in all the other layers at all the stages of the oestrous cycle. The results indicated that the HA varied with the steroid status. Higher HA values at a time when cervical relaxation is naturally higher may indicate its involvement in remodelling of the cervix at oestrus.

Target specific tumor treatment by VEGF siRNA complexed with reducible polyethyleneimine-hyaluronic acid conjugate

Target specific delivery of small interfering RNA (siRNA) has been regarded as one of the most important technologies for the development of siRNA therapeutics. In this work, non-toxic low molecular weight (MW) polyethyleneimine (PEI, 2000 Da) was cross-linked with cystamine bisacrylamide (CBA) to prepare reducible PEI-SS in the body. Then, PEI-SS was conjugated with hyaluronic acid (HA) in the form of block-copolymer to enhance serum stability and facilitate target specific cellular uptake of siRNA by HA receptor mediated endocytosis. The cytotoxicity of (PEI-SS)-b-HA conjugate appeared to be negligible likely due to the degradation of PEI-SS to low MW PEI in the cytosol. Flow cytometric and confocal microscopic analyses confirmed the HA receptor mediated endocytosis of siRNA/(PEI-SS)-b-HA complex. The siRNA/(PEI-SS)-b-HA complex demonstrated an excellent in vitro gene silencing efficiency in the range of 50-80% reducing the mRNA expression level in the absence and presence of 50 vol% serum. Moreover, intra-tumoral injection of vascular endothelial growth factor (VEGF) siRNA/(PEI-SS)-b-HA complex resulted in dramatically inhibited tumor growth with reduced VEGF mRNA and VEGF levels in the tumors.