A novel role of breast cancer-derived hyaluronan on inducement of M2-like tumor-associated macrophages formation

Extracellular Matrix/Glycopeptide Hybrid Hydrogel as an Immunomodulatory Niche for Endogenous Cardiac Repair after Myocardial Infarction

The treatment of myocardial infarction (MI) remains a substantial challenge due to excessive inflammation, massive cell death, and restricted regenerative potential, leading to maladaptive healing process and eventually heart failure. Current strategies of regulating inflammation or improving cardiac tissue regeneration have limited success. Herein, a hybrid hydrogel coassembled by acellular cardiac extracellular matrix (ECM) and immunomodulatory glycopeptide is developed for endogenous tissue regeneration after MI. The hydrogel constructs a niche recapitulating the architecture of native ECM for attracting host cell homing, controlling macrophage differentiation via glycopeptide unit, and promoting endotheliocyte proliferation by enhancing the macrophage-endotheliocyte crosstalk, which coordinate the innate healing mechanism for cardiac tissue regeneration. In a rodent MI model, the hybrid hydrogel successfully orchestrates a proreparative response indicated by enhanced M2 macrophage polarization, increased angiogenesis, and improved cardiomyocyte survival, which alleviates infarct size, improves wall thicknesses, and enhances cardiac contractility. Furthermore, the safety and effectiveness of the hydrogel are demonstrated in a porcine MI model, wherein proteomics verifies the regulation of immune response, proangiogenesis, and accelerated healing process. Collectively, the injectable composite hydrogel serving as an immunomodulatory niche for promoting cell homing and proliferation, inflammation modulation, tissue remodeling, and function restoration provides an effective strategy for endogenous cardiac repair.

CD44 is a potential immunotherapeutic target and affects macrophage infiltration leading to poor prognosis

CD44 plays a key role in the communication of CSCs with the microenvironment and the regulation of stem cell properties. UALCAN was used to analyze the expression of CD44 in bladder cancer (BLCA) and normal tissue. The UALCAN was utilized to analyze the prognostic value of CD44 in BLCA. The TIMER database was used to explore the relationship between CD44 and PD-L1; CD44 and tumor-infiltrating immune cells. The regulatory effect of CD44 on PD-L1 was verified by cell experiments in vitro. IHC confirmed the results of the bioinformatics analysis. GeneMania and Metascape were used to analyze protein-protein interaction (PPI) investigations and functional enrichment analysis. We found that BLCA patients with high CD44 expression had worse survival than those with low CD44 expression (P < 0.05). IHC and the TIMER database results showed that CD44 expression was positively correlated with PD-L1 expression (P < 0.05). At the cellular level, the expression of PD-L1 was significantly inhibited after CD44 expression was inhibited by siRNA. Immune infiltration analysis showed that CD44 expression levels in BLCA were significantly correlated with immune infiltration levels of different immune cells. IHC staining results further confirmed that the expression of CD44 in tumor cells was positively associated with the number of CD68⁺ macrophages and CD163⁺ macrophages (P < 0.05). Our results suggest that CD44 is a positive regulator of PD-L1 in BLCA and may be a key regulator of tumor macrophages infiltration and may be involved in M2 macrophage polarization. Our study provided new insights into the prognosis and immunotherapy of BLCA patients through macrophage infiltration and immune checkpoints.

β-Glucan produced by Lentinus edodes suppresses breast cancer progression via the inhibition of macrophage M2 polarization by integrating autophagy and inflammatory signals

BACKGROUND

β-Glucan from Lentinus edodes (LNT), an edible mushroom, possesses strong anticancer activity. However, the therapeutic effects of LNT during the occurrence and progression of breast cancer and their underlying molecular mechanisms have not been elucidated.

METHODS

Mouse mammary tumor virus-polyoma middle tumor-antigen (MMTV-PyMT) transgenic mice were used as a breast cancer mouse model. Hematoxylin and eosin, immunohistochemical, and immunofluorescence staining were performed for histopathological analysis. Moreover, we developed an inflammatory cell model using tumor necrosis factor-α (TNF-α). Macrophage polarization was assessed using western blot analysis and immunofluorescence.

RESULTS

Orphan nuclear receptor 77 (Nur77) and sequestosome-1 (p62) were highly expressed and positively correlated with each other in breast cancer tissues. LNT significantly inhibited tumor growth, ameliorated inflammatory cell infiltration, and induced tumor cell apoptosis in PyMT transgenic mice. Moreover, LNT attenuated the ability of tumors to metastasize to lung tissue. Mechanistically, LNT treatment restrained macrophage polarization from M1 to M2 phenotype and promoted autophagic cell death by inhibiting Nur77 expression, AKT/mTOR signaling, and inflammatory signals in breast tumor cells. However, LNT did not exhibit a direct pro-autophagic effect on tumor cell death, except for its inhibitory effect on Nur77 expression. LNT-mediated autophagic tumor cell death depends on M1 macrophage polarization. In in vitro experiments, LNT inhibited the upregulation of p62, autophagy activation, and inflammatory signaling pathways in Nur77 cells.

CONCLUSION

LNT inhibited macrophage M2 polarization and subsequently blocked the AKT/mTOR and inflammatory signaling axes in breast cancer cells, thereby promoting autophagic tumor cell death. Thus, LNT may be a promising therapeutic strategy for breast cancer.

The Matrix Reloaded—The Role of the Extracellular Matrix in Cancer

As the core component of all organs, the extracellular matrix (ECM) is an interlocking macromolecular meshwork of proteins, glycoproteins, and proteoglycans that provides mechanical support to cells and tissues. In cancer, the ECM can be remodelled in response to environmental cues, and it controls a plethora of cellular functions, including metabolism, cell polarity, migration, and proliferation, to sustain and support oncogenesis. The biophysical and biochemical properties of the ECM, such as its structural arrangement and being a reservoir for bioactive molecules, control several intra- and intercellular signalling pathways and induce cytoskeletal changes that alter cell shapes, behaviour, and viability. Desmoplasia is a major component of solid tumours. The abnormal deposition and composition of the tumour matrix lead to biochemical and biomechanical alterations that determine disease development and resistance to treatment. This review summarises the complex roles of ECM in cancer and highlights the possible therapeutic targets and how to potentially remodel the dysregulated ECM in the future. Furthering our understanding of the ECM in cancer is important as the modification of the ECM will probably become an important tool in the characterisation of individual tumours and personalised treatment options.

Anti-Inflammatory Effects of the 35kDa Hyaluronic Acid Fragment (B-HA/HA35)

Background

Hyaluronic acid (HA) and HA fragments interact with a variety of human body receptors and are involved in the regulation of various physiological functions and leukocyte trafficking in the body. Accordingly, the development of an injectable HA fragment with good tissue permeability, the identification of its indications, and molecular mechanisms are of great significance for its clinical application. The previous studies showed that the clinical effects of injectable 35kDa B-HA result from B-HA binding to multiple receptors in different cells, tissues, and organs. This study lays the foundation for further studies on the comprehensive clinical effects of injectable B-HA.

Methods

We elaborated on the production process, bioactivity assay, efficacy analyses, and safety evaluation of an injectable novel HA fragment with an average molecular weight of 35 kDa (35 kDa B-HA), produced by recombinant human hyaluronidase PH20 digestion.

Results

The results showed that 35 kDa B-HA induced human erythrocyte aggregation (rouleaux formation) and accelerated erythrocyte sedimentation rates through the CD44 receptor. B-HA application and injection treatment significantly promoted the removal of mononuclear cells from the site of inflammation and into the lymphatic circulation. At a low concentration, 35 kDa B-HA inhibited production of reactive oxygen species and tumor necrosis factor by neutrophils; at a higher concentration, 35 kDa B-HA promoted the migration of monocytes. Furthermore, 35 kDa B-HA significantly inhibited the migration of neutrophils with or without lipopolysaccharide treatment, suggesting that in local tissues, higher concentrations of 35 kDa B-HA have antiinflammatory effects. After 99mTc radiolabeled 35 kDa B-HA was intravenously injected into mice, it quickly entered into the spleen, liver, lungs, kidneys and other organs through the blood circulation.

Conclusion

This study demonstrated that the HA fragment B-HA has good tissue permeability and antiinflammatory effects, laying a theoretical foundation for further clinical studies.

Macrophage response mediated by extracellular matrix: recent progress

Biomaterials are one of efficient treatment options for tissue defects in regenerative medicine. Compared to synthetic materials which tend to induce chronic inflammatory response and fibrous capsule, extracellular matrix (ECM) scaffold materials composed of biopolymers are thought to be capable of inducing a pro-regenerative immune microenvironment and facilitate wound healing. Immune cells are the first line of response to implanted biomaterials. In particular, macrophages greatly affect cell behavior and the ultimate treatment outcome based on multiple cell phenotypes with various functions. The macrophage polarization status is considered as a general reflection of the characteristics of the immune microenvironment. Since numerous reports has emphasized the limitation of classical M1/M2 nomenclature, high-resolution techniques such as single-cell sequencing has been applied to recognize distinct macrophage phenotypes involved in host responses to biomaterials. After reviewing latest literatures that explored the immune microenvironment mediated by ECM scaffolds, this paper describe the behaviors of highly heterogeneous and plastic macrophages subpopulations which affect the tissue regeneration. The mechanisms by which ECM scaffolds interact with macrophages are also discussed from the perspectives of the ECM ultrastructure along with the nucleic acid, protein, and proteoglycan compositions, in order to provide targets for potential therapeutic modulation in regenerative medicine.

[Relationship between PD-L1 expression and tumor stem cell marker CD44 as a promising basis for the development of new approaches to cancer targeted therapy]

Immunotherapy of malignant tumors is a rapidly developing area of oncology. PD-1 is a receptor expressed by activated T-lymphocytes. As a result of its interaction with the ligand (PD-L1 or PD-L2), the activity of T-lymphocytes is inhibited and their apoptosis occurs. Drugs that inhibit the interaction of PD-1 with ligands have an immunostimulatory effect and are effective in the treatment of many types of neoplasms: melanoma, lung cancer, bladder cancer, stomach cancer, various lymphomas, etc. However, response to this treatment is observed only in a narrow cohort of patients. To increase the effectiveness of immunotherapy, combined preparations and nanoparticles are being developed and created to enhance the effect of PD-L1 inhibitors, and containing hyaluronic acid as a ligand for the CD44 protein, which is expressed in many human tumors. However, the issue of co-expression of CD44 and PD-L1 remains poorly understood. This review is devoted to describing the features of co-expression and the mechanisms of interaction between CD44 and PD-L1. Promising directions for the development of new approaches to the immunotherapy of malignant tumors are presented.

The glycocalyx and immune evasion in cancer

In order to establish malignant lesions, tumors must first evade their detection by immune cells. Tumors achieve this by embellishing and tailoring their glycocalyx, a network of polysaccharides and glycosylated proteins that refracts the phagocytic efforts of myeloid cells, shrouds neoantigens and other ligands from cells of the acquired immune system, and skews immune responses. The barriers imposed by the glycocalyx are biophysical and also linked to the inhibitory receptor signaling pathways of immune cells that engage tumor sialic acids as markers of healthy "self". This would explain the pressure for cancers to upregulate the synthases, transmembrane mucins, and other heavily sialylated glycoproteins involved in establishing a repulsive glycocalyx. Accordingly, individual tumor cells that are best capable of constructing a shielding glycocalyx on their surface show higher metastatic potential in immunocompetent mice. Reciprocally, therapeutics have recently been devised to edit and dismantle the glycocalyx barrier in an effort to invigorate an immune response aimed at tumor destruction. We discuss the features of the tumor-associated glycocalyx that afford immune evasion of cancers and how strategies that target this barrier may potentiate antitumor immunity.

The pleiotropic mode and molecular mechanism of macrophages in promoting tumor progression and metastasis

Macrophages are the most abundant immune cells in primary and metastatic tumor tissues. Studies have shown that macrophages mainly exhibit a tumor-promoting phenotype and play a key role in tumor progression and metastasis. Therefore, many macrophage-targeted drugs have entered clinical trials. However, compared to preclinical studies, some clinical trial results showed that macrophage-targeted therapy did not achieve the desired effect. This may be because most of what we know about macrophages comes from in vitro experiments and animal models, while macrophages in the more complex human microenvironment are still poorly understood. With the development of technologies such as single-cell RNA sequencing, we have gained a new understanding of the origin, classification and functional mechanism of tumor-associated macrophages. Therefore, this study reviewed the recent progress of macrophages in promoting tumor progression and metastasis, aiming to provide some help for the formulation of optimal strategies for macrophage-targeted therapy.

Glioblastoma extracellular vesicles influence glial cell hyaluronic acid deposition to promote invasiveness

Background

Infiltration of glioblastoma (GBM) throughout the brain leads to its inevitable recurrence following standard-of-care treatments, such as surgical resection, chemo-, and radiotherapy. A deeper understanding of the mechanisms invoked by GBM to infiltrate the brain is needed to develop approaches to contain the disease and reduce recurrence. The aim of this study was to discover mechanisms through which extracellular vesicles (EVs) released by GBM influence the brain microenvironment to facilitate infiltration, and to determine how altered extracellular matrix (ECM) deposition by glial cells might contribute to this.

Methods

CRISPR was used to delete genes, previously established to drive carcinoma invasiveness and EV production, from patient-derived primary and GBM cell lines. We purified and characterized EVs released by these cells, assessed their capacity to foster pro-migratory microenvironments in mouse brain slices, and evaluated the contribution made by astrocyte-derived ECM to this. Finally, we determined how CRISPR-mediated deletion of genes, which we had found to control EV-mediated communication between GBM cells and astrocytes, influenced GBM infiltration when orthotopically injected into CD1-nude mice.

Results

GBM cells expressing a p53 mutant (p53R273H) with established pro-invasive gain-of-function release EVs containing a sialomucin, podocalyxin (PODXL), which encourages astrocytes to deposit ECM with increased levels of hyaluronic acid (HA). This HA-rich ECM, in turn, promotes migration of GBM cells. Consistently, CRISPR-mediated deletion of PODXL opposes infiltration of GBM in vivo.

Conclusions

This work describes several key components of an EV-mediated mechanism though which GBM cells educate astrocytes to support infiltration of the surrounding healthy brain tissue.

Targeting the tumor stroma for cancer therapy

Tumors are comprised of both cancer cells and surrounding stromal components. As an essential part of the tumor microenvironment, the tumor stroma is highly dynamic, heterogeneous and commonly tumor-type specific, and it mainly includes noncellular compositions such as the extracellular matrix and the unique cancer-associated vascular system as well as a wide variety of cellular components including activated cancer-associated fibroblasts, mesenchymal stromal cells, pericytes. All these elements operate with each other in a coordinated fashion and collectively promote cancer initiation, progression, metastasis and therapeutic resistance. Over the past few decades, numerous studies have been conducted to study the interaction and crosstalk between stromal components and neoplastic cells. Meanwhile, we have also witnessed an exponential increase in the investigation and recognition of the critical roles of tumor stroma in solid tumors. A series of clinical trials targeting the tumor stroma have been launched continually. In this review, we introduce and discuss current advances in the understanding of various stromal elements and their roles in cancers. We also elaborate on potential novel approaches for tumor-stroma-based therapeutic targeting, with the aim to promote the leap from bench to bedside.

HAS2-Ezrin-ER axis plays a role in acquired antiestrogen resistance of ER-positive breast cancer

The development of endocrine resistance is a major clinical problem in estrogen receptor-positive (ER+) breast cancer (BrCa) treatment, in which how cancer cells acquire resistance remains obscure. Hyaluronan synthase 2 (HAS2) is the most critical synthase in producing hyaluronan and is well known for its involvement in cancer growth, metabolism and metastasis. Recent evidence has proved that HAS2 is involved in cellular acquired resistance to drug therapy in BrCa. In this work, we first observed that HAS2 expression was decreased in the endocrine-resistant ER+ BrCa cells. Further knocking-out experiments confirmed that the loss of HAS2 in parental ER+ BrCa cells resulted in a following antiestrogen resistance. Next, we found that the HAS2-loss could induce an upregulation of Ezrin, a member of the membrane cytoskeletal protein family who plays key roles in cellular signal transduction. Notably, we identified that the increase of Ezrin induced by HAS2-loss could inhibit the ERα expression and augment antiestrogen resistance, suggesting that a HAS2-Ezrin-ER axis may be associated with the acquirement of endocrine resistance in ER+ BrCa cells. Finally, knockdown or inhibition of Ezrin could restore the sensitivity of endocrine-resistant cells to antiestrogens treatment by activating ERα signaling. Taken together, our findings unraveled a novel HAS2-Ezrin-ER route in regulating the sensitivity of ER+ BrCa cells to antiestrogens, in which Ezrin may be a potential target in endocrine therapy.

The role of macrophage scavenger receptor 1 (MSR1) in inflammatory disorders and cancer

Macrophage scavenger receptor 1 (MSR1), also named CD204, holds key inflammatory roles in multiple pathophysiologic processes. Present primarily on the surface of various types of macrophage, this receptor variably affects processes such as atherosclerosis, innate and adaptive immunity, lung and liver disease, and more recently, cancer. As highlighted throughout this review, the role of MSR1 is often dichotomous, being either host protective or detrimental to the pathogenesis of disease. We will discuss the role of MSR1 in health and disease with a focus on the molecular mechanisms influencing MSR1 expression, how altered expression affects disease process and macrophage function, the limited cell signalling pathways discovered thus far, the emerging role of MSR1 in tumour associated macrophages as well as the therapeutic potential of targeting MSR1.

Activation of CD44 signaling in leader cells induced by tumor-associated macrophages drives collective detachment in luminal breast carcinomas

Collective detachment of cancer cells at the invading front could generate efficient metastatic spread. However, how cancer cell clusters shed from the leading front remains unknown. We previously reported that the dynamic expression of CD44 in breast cancers (BrCas) at collectively invading edges was associated with tumor-associated macrophages (TAMs). In this study, we first observed that the highly expressed CD44 (CD44^high) cancer cell clusters were located in the BrCa circulating vessels, accompanied by CD206⁺ TAMs. Next, we identified that the cancer cell clusters can be converted to an invasive CD44^high state which was induced by TAMs, thus giving rise to CD44-associated signaling mediated cohesive detachment. Then, we showed that disrupting CD44-signaling inhibited the TAMs triggered cohesive detaching using 3D organotypic culture and mouse models. Furthermore, our mechanistic study showed that the acquisition of CD44^high state was mediated by the MDM2/p53 pathway activation which was induced by CCL8 released from TAMs. Blocking of CCL8 could inhibit the signaling cascade which decreased the CD44-mediated cohesive detachment and spread. Our findings uncover a novel mechanism underlying collective metastasis in BrCas that may be helpful to seek for potential targets.

Suppression of the hyaluronic acid pathway induces M1 macrophages polarization via STAT1 in glioblastoma

Immunosuppressive tumor microenvironment is a crucial factor that impedes the success of tumor immunotherapy, and tumor-associated macrophages (TAMs) are essential for the formation of tumor immunosuppressive microenvironment. Hyaluronic acid (HA) is highly important brick for glioblastoma microenvironment, but whether it contributes to TAM polarization and glioblastoma immunosuppressive microenvironment is less well known. In our study, we observed that disrupting glioblastoma HA synthesis or blocking HA binding to its receptor CD44 on macrophages increased the proportion of M1 macrophages by upregulating SIRPα in macrophages, the underlying mechanism was elevated SIRPα enhanced STAT1 phosphorylation and suppressed STAT3 phosphorylation in macrophages. Subsequently, the induced macrophages could inhibit glioblastoma growth via a feedback effect. In addition, 4-methylumbelliferone (4MU), a cholecystitis drug, can disrupt the CD47/SIRPα axis by disturbing glioblastoma HA synthesis. Collectively, these findings indicated that HA plays a crucial role in macrophages polarization and CD47/SIRPα signaling between glioblastoma cells and macrophages, and suppressing the HA pathway may be a new immunotherapeutic approach for glioblastoma.

Hyaluronan as "Agent Smith" in cancer extracellular matrix pathobiology: Regulatory roles in immune response, cancer progression and targeting

Extracellular matrix (ECM) critically regulates cancer cell behavior by governing cell signaling and properties. Hyaluronan (HA) acts as a structural and functional ECM component that mediates critical properties of cancer cells in a molecular size-dependent manner. HA fragments secreted by cancer-associated fibroblasts (CAFs) reveal the correlation of HA to CAF-mediated matrix remodeling, a key step for the initiation of metastasis. The main goal of this article is to highlight the vital functions of HA in cancer cell initiation and progression as well as HA-mediated paracrine interactions among cancer and stromal cells. Furthermore, the HA implication in mediating immune responses to cancer progression is also discussed. Novel data on the role of HA in the formation of pre-metastatic niche may contribute towards the improvement of current theranostic approaches that benefit cancer management.

Tumor microenvironment remodeling modulates macrophage phenotype in breast cancer lymphangiogenesis

Hyaluronan (HA) is dynamically remodeled in tumor microenvironment (TME) and is reported to be closely related to tumor lymphatic metastasis by inducing lymphangiogenesis. Macrophages are known to be involved in neo-lymphatic vessels formation. However, few studies have investigated the role of HA-mediated TME remodeling on macrophages-dependent lymphangiogenesis. We previously showed that HA could drive macrophages to acquire the M2 phenotype. In this study, we attempt to study the crosstalk between HA in TME and macrophages dependent lymphangiogenesis. First, we found that the abundant assembly of HA in breast cancer tissue was accompanied by increased infiltration of macrophages featured by expressing lymphatic endothelial markers. Then, to further identify the remodeling of HA in regulating macrophage phenotype, we used HA fragments which are usually enriched in TME for this purpose. Our results showed that the reconstructed HA could induce bone marrow-derived macrophages (BMDMs) to express markers of lymphatic endothelium and form tube-like structures, suggesting a novel function of HA from TME on macrophages-dependent lymphangiogenesis. Finally, we found that inhibition of the HA-TLR4 pathway could reduce the ability of BMDMs to exhibit lymphatic endothelial phenotype. Our results provide new insight into tumor microenvironment remodeling and macrophages in breast cancer lymphangiogenesis.

Tumor Cells and the Extracellular Matrix Dictate the Pro-Tumoral Profile of Macrophages in CRC

Tumor-associated macrophages (TAMs) are major components of the tumor microenvironment. In colorectal cancer (CRC), a strong infiltration of TAMs is accompanied by a decrease in effector T cells and an increase in the metastatic potential of CRC. We investigated the functional profile of TAMs infiltrating CRC tissue by immunohistochemistry, flow cytometry, ELISA, and qRT-PCR and their involvement in impairing the activation of effector T cells. In CRC biopsies, we evidenced a high percentage of macrophages with low expression of the antigen-presenting complex MHC-II and high expression of CD206. Monocytes co-cultured with tumor cells or a decellularized tumor matrix differentiated toward a pro-tumoral macrophage phenotype characterized by decreased expression of MHC-II and CD86 and increased expression of CD206 and an abundant release of pro-tumoral cytokines and chemokines. We demonstrated that the hampered expression of MHC-II in macrophages is due to the downregulation of the MHC-II transactivator CIITA and that this effect relies on increased expression of miRNAs targeting CIITA. As a result, macrophages become unable to present antigens to CD4 T lymphocytes. Our data suggest that the tumor microenvironment contributes to defining a pro-tumoral profile of macrophages infiltrating CRC tissue with impaired capacity to activate T cell effector functions.

Coordinated regulation of immune contexture: crosstalk between STAT3 and immune cells during breast cancer progression

Recent insights into the molecular and cellular mechanisms underlying cancer development have revealed the tumor microenvironment (TME) immune cells to functionally affect the development and progression of breast cancer. However, insufficient evidence of TME immune modulators limit the clinical application of immunotherapy for advanced and metastatic breast cancers. Intercellular STAT3 activation of immune cells plays a central role in breast cancer TME immunosuppression and distant metastasis. Accumulating evidence suggests that targeting STAT3 and/or in combination with radiotherapy may enhance anti-cancer immune responses and rescue the systemic immunologic microenvironment in breast cancer. Indeed, apart from its oncogenic role in tumor cells, the functions of STAT3 in TME of breast cancer involve multiple types of immunosuppression and is associated with tumor cell metastasis. In this review, we summarize the available information on the functions of STAT3-related immune cells in TME of breast cancer, as well as the specific upstream and downstream targets. Additionally, we provide insights about the potential immunosuppression mechanisms of each type of evaluated immune cells. Video abstract.

Hyaluronan synthase 2 (HAS2) regulates cell phenotype and invadopodia formation in luminal-like breast cancer cells

Although luminal breast cancer cells are typically highly cohesive epithelial cells and have low invasive ability, many eventually develop metastasis. Until now, the underlying mechanisms remain obscure. In this work, we showed that the level of hyaluronic acid synthase 2 (HAS2) was positively correlated with the malignant phenotype of breast cancer cells. Notably, the increased expression of HAS2 promoted the invasive and migratory abilities of luminal breast cancer cells in vitro, followed by a reduced expression of E-cadherin, β-catenin, and ZO-1, and an elevated expression of N-cadherin and vimentin. Furthermore, overexpression of HAS2 promoted while knockdown of HAS2 impeded invadopodia formation, which subsequently increased or decreased the activation of cortactin, Tks5, and metalloproteinases (MMPs). Activation of these invadopodia-related proteins was prevented by inhibition of HAS2 or disruption of HA, which in turn attenuated the increased motility and invasiveness. Further, in vivo study showed that, HAS2 increased tumor growth and the rate of lung metastasis via driving transition to an invasive cell phenotype in SCID mice that were orthotopically transplanted with luminal breast cancer cells. Collectively, our results showed that HAS2 promoted cell invasion by inducing transition to an invasive phenotype and by enhancing invadopodia formation in luminal breast cancer cells, which may provide new mechanistic insights into its role in tumor metastasis.

Modification of Extracellular Matrix Enhances Oncolytic Adenovirus Immunotherapy in Glioblastoma

PURPOSE

Extracellular matrix (ECM) component hyaluronan (HA) facilitates malignant phenotypes of glioblastoma (GBM), however, whether HA impacts response to GBM immunotherapies is not known. Herein, we investigated whether degradation of HA enhances oncolytic virus immunotherapy for GBM.

EXPERIMENTAL DESIGN

Presence of HA was examined in patient and murine GBM. Hyaluronidase-expressing oncolytic adenovirus, ICOVIR17, and its parental virus, ICOVIR15, without transgene, were tested to determine if they increased animal survival and modulated the immune tumor microenvironment (TME) in orthotopic GBM. HA regulation of NF-κB signaling was examined in virus-infected murine macrophages. We combined ICOVIR17 with PD-1 checkpoint blockade and assessed efficacy and determined mechanistic contributions of tumor-infiltrating myeloid and T cells.

RESULTS

Treatment of murine orthotopic GBM with ICOVIR17 increased tumor-infiltrating CD8+ T cells and macrophages, and upregulated PD-L1 on GBM cells and macrophages, leading to prolonged animal survival, compared with control virus ICOVIR15. High molecular weight HA inhibits adenovirus-induced NF-κB signaling in macrophages in vitro, linking HA degradation to macrophage activation. Combining ICOVIR17 with anti-PD-1 antibody further extended the survival of GBM-bearing mice, achieving long-term remission in some animals. Mechanistically, CD4+ T cells, CD8+ T cells, and macrophages all contributed to the combination therapy that induced tumor-associated proinflammatory macrophages and tumor-specific T-cell cytotoxicity locally and systemically.

CONCLUSIONS

Our studies are the first to show that immune modulatory ICOVIR17 has a dual role of mediating degradation of HA within GBM ECM and subsequently modifying the immune landscape of the TME, and offers a mechanistic combination immunotherapy with PD-L1/PD-1 blockade that remodels innate and adaptive immune cells.

The scrambled story between hyaluronan and glioblastoma

Advances in cancer biology are revealing the importance of the cancer cell microenvironment on tumorigenesis and cancer progression. Hyaluronan (HA), the main glycosaminoglycan in the extracellular matrix, has been associated with the progression of glioblastoma (GBM), the most frequent and lethal primary tumor in the central nervous system, for several decades. However, the mechanisms by which HA impacts GBM properties and processes have been difficult to elucidate. In this review, we provide a comprehensive assessment of the current knowledge on HA's effects on GBM biology, introducing its primary receptors CD44 and RHAMM and the plethora of relevant downstream signaling pathways that can scramble efforts to directly link HA activity to biological outcomes. We consider the complexities of studying an extracellular polymer and the different strategies used to try to capture its function, including 2D and 3D in vitro studies, patient samples, and in vivo models. Given that HA affects not only migration and invasion, but also cell proliferation, adherence, and chemoresistance, we highlight the potential role of HA as a therapeutic target. Finally, we review the different existing approaches to diminish its protumor effects, such as the use of 4-methylumbelliferone, HA oligomers, and hyaluronidases and encourage further research along these lines in order to improve the survival and quality of life of GBM patients.

Hyaluronan: Metabolism and Function

As a major polysaccharide component of the extracellular matrix, hyaluronan plays essential roles in the organization of tissue architecture and the regulation of cellular functions, such as cell proliferation and migration, through interactions with cell-surface receptors and binding molecules. Metabolic pathways for biosynthesis and degradation tightly control the turnover rate, concentration, and molecular size of hyaluronan in tissues. Despite the relatively simple chemical composition of this polysaccharide, its wide range of molecular weights mediate diverse functions that depend on molecular size and tissue concentration. Genetic engineering and pharmacological approaches have demonstrated close associations between hyaluronan metabolism and functions in many physiological and pathological events, including morphogenesis, wound healing, and inflammation. Moreover, emerging evidence has suggested that the accumulation of hyaluronan extracellular matrix and fragments due to the altered expression of hyaluronan synthases and hyaluronidases potentiates cancer development and progression by remodeling the tumor microenvironment. In addition to the well-known functions exerted by extracellular hyaluronan, recent metabolomic approaches have also revealed that its synthesis can regulate cellular functions via the reprogramming of cellular metabolism. This review highlights the current advances in knowledge on the biosynthesis and catabolism of hyaluronan and describes the diverse functions associated with hyaluronan metabolism.

Folic acid-modified Exosome-PH20 enhances the efficiency of therapy via modulation of the tumor microenvironment and directly inhibits tumor cell metastasis

High accumulation of hyaluronan (HA) in the tumor microenvironment leads to an increase in the interstitial pressure and reduction perfusion of drugs. Furthermore, high molecular-weight (HMW)-HA suppresses M1 macrophage polarization, enhances M2 polarization, and induces immunosuppression. Hyaluronidase treatment have attempted to decrease the quantity of HA in tumors. However, hyaluronidase-driven HA degradation driven accelerates tumor cell metastasis, which is a major cause of mortality in cancer patients. Thus, we designed a novel exosome-based drug delivery system (DDS), named Exos-PH20-FA, using genetic engineering to express human hyaluronidase (PH20) and self-assembly techniques to modify the exosomes with folic acid (FA). Our results show that Exos-PH20-FA degraded HMW-HA to low-molecular-weight (LMW)-HA. Moreover, LMW-HA polarized macrophages to the M1 phenotype and reduced the number of relevant immunosuppressive immunocytes which changed the immune microenvironment from an immunosuppressive to immunosupportive phenotype. Furthermore, we demonstrated Exos-PH20-FA directly reduced hyaluronidase-induced metastasis of tumor cells. This tumor treatment also allowed an enhanced delivery of chemotherapy by tumor-targeting effect with FA modification. Our findings indicate that Exos-PH20-FA improves tumor treatment efficiency and reduces the side effects of hyaluronidase treatment, namely tumor cell metastasis. This all-in-one exosome-based HA targeting DDS maybe a promising treatment that yields more efficient and safer results.

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High molecular-weight hyaluronan is related to tumor progression.

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The degradation of hyaluronan enhance cancer cell migration and metastasis.

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Folic acid can target tumor and inhibit tumor cell migration.

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Exosomes are ideal carriers for chemotherapeutics, folic acid and hyaluronidase.

The standard form of CD44 as a marker for invasion of encapsulated papillary carcinoma of the breast

Encapsulated papillary carcinoma (EPC), a rare variant of papillary carcinoma of the breast, is regarded as a transition form between carcinoma in situ and invasive carcinoma. Here, we tried to identify differences in immunohistochemical phenotype between 10 EPCs with invasive properties (EPC with invasion) and 17 non-invasive EPCs (EPC). We immunohistochemically assessed the expression of hormone receptors, matrix metalloproteinase (MMP) 2 and MMP9, vascular endothelial growth factor (VEGF), CD31, and D2-40, markers of tumor-associated macrophages (CD163, CD206), Ki-67 and stem cell markers (CD44 and CD24). The frequency of MMP9-positive cases and the number of tumor-associated macrophages infiltrating into the fibrous capsule were significantly higher in EPC with invasion than in EPC. The expression of the standard form of CD44 (CD44s) was significantly stronger in EPC with invasion than in EPC (P = 0.0036) and was correlated with MMP2 expression and M2-like macrophage infiltration. A multivariate logistic model analysis showed that CD44s expression in tumor cell and infiltration of CD163 positive macrophage in EPC capsule showed an independent odds ratio for invasion of EPC. Thus, CD44s may be a potential marker predicting invasive potential of EPC and could play an important role in progression to the invasive phase of EPC.

Collagen Density Modulates the Immunosuppressive Functions of Macrophages

Tumor-associated macrophages (TAMs) support tumor growth by suppressing the activity of tumor-infiltrating T cells. Consistently, TAMs are considered a major limitation for the efficacy of cancer immunotherapy. However, the molecular reason behind the acquisition of an immunosuppressive TAM phenotype is not fully clarified. During tumor growth, the extracellular matrix (ECM) is degraded and substituted with a tumor-specific collagen-rich ECM. The collagen density of this tumor ECM has been associated with poor patient prognosis but the reason for this is not well understood. In this study, we investigated whether the collagen density could modulate the immunosuppressive activity of TAMs. The murine macrophage cell line RAW 264.7 was three-dimensionally cultured in collagen matrices of low and high collagen densities mimicking healthy and tumor tissue, respectively. Collagen density did not affect proliferation or viability of the macrophages. However, whole-transcriptome analysis revealed a striking response to the surrounding collagen density, including the regulation of immune regulatory genes and genes encoding chemokines. These transcriptional changes were shown to be similar in murine bone marrow-derived macrophages and TAMs isolated from murine tumors. Strikingly, coculture assays with primary T cells showed that macrophages cultured in high-density collagen were less efficient at attracting cytotoxic T cells and capable of inhibiting T cell proliferation more than macrophages cultured in low-density collagen. Our study demonstrates that a high collagen density can instruct macrophages to acquire an immunosuppressive phenotype. This mechanism could reduce the efficacy of immunotherapy and explain the link between high collagen density and poor prognosis.

Remodelling of the bone marrow microenvironment by stromal hyaluronan modulates the malignancy of breast cancer cells

Background

Hyaluronan (HA) is an abundant component of the bone marrow (BM) extracellular matrix. Here, we investigated the abnormal deposition of HA in the BM microenvironment and its remodelling in mediating the malignancy of breast cancer cells (BCCs).

Methods

BCCs were transplanted into nude mice by intracardiac injection. The BCCs were cocultured with BM-derived stromal HS5 cells. Then, the abnormal metabolism of HA and its correlation with the malignant growth and the intracellular signalling pathways of the BCCs were investigated. After knockdown/out of the HA receptor CD44 in cancer cells by shRNA and CRISPR/Cas9, the mechanism was investigated in vivo through intratibial inoculation and in vitro by coculture with HS5 cells.

Results

The malignancy of cancer cells was highly related to the degree of accumulation of HA in the BM. Further, stromal cell-derived HA, especially the mixed complex, significantly promoted the growth of BCCs and osteolysis by binding to the CD44 receptor. Additionally, the investigation of the underlying mechanism revealed that the PI3K, Cyclin D1, and CDK4 pathways were involved in the effect of bone stromal cell-derived HA on the BCC activities.

Conclusion

These data suggested that HA in abnormal BM stroma might be a therapeutic candidate for bone metastasis of breast cancer.

Wnt5a-induced M2 polarization of tumor-associated macrophages via IL-10 promotes colorectal cancer progression

Background

Tumor-associated macrophages (TAMs) in the tumor microenvironment influence tumor initiation, invasion and metastasis. Several studies have shown that Wnt5a is mainly expressed in the tumor stroma, especially in TAMs. However, whether Wnt5a regulates the polarization and biological function of TAMs in colorectal cancer (CRC) is incompletely understood.

Methods

Immunofluorescence staining was performed to detect CD68 and Wnt5a expression in colorectal tissues from patients (63 CRC specimens VS 20 normal tissues). RT-qPCR, flow cytometry, ELISA and inhibitors were carried out to explore the role of Wnt5a in the polarization of TAMs. Clone formation and transwell assays were performed to determine the effects of Wnt5a–treated macrophages on tumor proliferation, migration and invasion in vitro. Finally, a xenograft model was applied to confirm the effects of Wnt5a⁺ TAMs on CRC tumorigenesis.

Results

We found that high Wnt5a⁺CD68⁺/CD68⁺ TAMs ratio was significantly associated with poor prognosis in CRC patients and Wnt5a⁺ TAM was an M2-like TAM subtype. Subsequently, we found that Wnt5a induced macrophages to secrete IL-10, which then acted as an autocrine cytokine to induce M2 polarization of these macrophages. IL-10 neutralizing antibody completely reversed the pro-M2 effect of Wnt5a. Mechanistically, the CaKMII-ERK1/2-STAT3 pathway was required for Wnt5a-mediated IL-10 expression in macrophages. Furthermore, Wnt5a-induced M2 macrophages promoted CRC cells proliferation, migration and invasion; knockdown of Wnt5a in TAMs significantly impaired the pro-tumor functions of TAMs.

Conclusions

Our data indicate that Wnt5a could induce M2 polarization of TAMs by regulating CaKMII-ERK1/2-STAT3 pathway–mediated IL-10 secretion, ultimately promoting tumor growth and metastasis of CRC.

Hyaluronic acid-based extracellular matrix triggers spontaneous M2-like polarity of monocyte/macrophage

Hyaluronic acid (HA) is found in various tumor tissues, and is considered tumor-associated extracellular matrix (ECM). Within this tumor-associated ECM, stromal cells, especially immune cells, are involved in tumor progression. However, the effects of tumor-associated ECM on the characteristics of immune cells remain unexplored. Therefore, we studied the triggering effect of HA on spontaneous M2-like polarity of monocytes/macrophages using HA-mixed collagen (HA-COL) matrix. In the presence of HA, expression of the HA receptor (CD44) and M2 polarity-related genes was upregulated in human monocytes (THP-1 cells). We confirmed the CD44-mediated activation of STAT3 in THP-1 cells cultured in an HA-rich environment. Furthermore, when we induced the THP-1 cells to differentiate into cells with M1 or M2 polarity within an HA-rich environment, the HA-rich environment influenced the direction of induction. Our findings might improve understanding of the crosstalk between immune cells and tumor-associated ECM, and facilitate development of tumor immunotherapy strategies.

Gastric cancer-derived mesenchymal stromal cells trigger M2 macrophage polarization that promotes metastasis and EMT in gastric cancer

Resident macrophages in the tumor microenvironment exert a dual role in tumor progression. So far, the mechanism of intratumoral macrophage generation is still largely unknown. In the present study, the importance of macrophages in the pro-tumor role of gastric cancer-derived mesenchymal stromal cells (GC-MSCs) was observed in a mouse xenograft model with macrophage depletion. In gastric cancer tissues, high expression levels of Ym-1, Fizz-1, arginase-1, and CCR-2, as well as a low expression level of iNOS, were verified, and co-localization of GC-MSCs and tumor-associated macrophages (TAMs) was observed by dual immunofluorescence histochemistry. TAMs isolated from gastric cancer tissues predominantly displayed an M2 phenotype. In a co-culture system, the contribution of GC-MSCs to M2 polarization of macrophages was confirmed by the M2-related protein expression, M2-like immunophenotype and cytokine profile of GC-MSC-primed macrophages in vitro. Blockade of IL-6/IL-8 by neutralizing antibodies significantly attenuated the promoting effect of GC-MSCs on M2-like macrophage polarization via the JAK2/STAT3 signaling pathway. In addition, GC-MSC-primed macrophages promoted the migration and invasion of gastric cancer cells, and the process of EMT in gastric cancer cells was significantly enhanced by GC-MSC-primed macrophage treatment. Our study showed that tumor-promoting GC-MSCs contribute to M2 macrophage polarization within the gastric cancer niche through considerable secretion of IL-6 and IL-8. These GC-MSC-primed macrophages can subsequently prompt gastric cancer metastasis via EMT promotion in gastric cancer cells.

CD44 Promotes PD-L1 Expression and Its Tumor-Intrinsic Function in Breast and Lung Cancers

The PD-L1 (CD274) immune-checkpoint ligand is often upregulated in cancers to inhibit T cells and elicit immunosuppression. Independent of this activity, PD-L1 has recently been shown to also exert a cancer cell-intrinsic function promoting tumorigenesis. Here, we establish this tumor-intrinsic role of PD-L1 in triple-negative breast cancer (TNBC) and non-small cell lung cancer (NSCLC). Using FACS-assisted shRNA screens, we identified the cell-surface adhesion receptor CD44 as a key positive regulator of PD-L1 expression in these cancers. Mechanistically, CD44 activated PD-L1 transcription in part through its cleaved intracytoplasmic domain (ICD), which bound to a regulatory region of the PD-L1 locus containing a consensus CD44-ICD binding site. Supporting this genetic interaction, CD44 positively correlated with PD-L1 expression at the mRNA and protein levels in primary tumor samples of TNBC and NSCLC patients. These data provide a novel basis for CD44 as a critical therapeutic target to suppress PD-L1 tumor-intrinsic function. SIGNIFICANCE: CD44 is a potential target to suppress PD-L1 function in TNBC. This finding has the potential to open a new area of therapy for TNBC.

Tumor microenvironment and breast cancer survival: combined effects of breast fat, M2 macrophages and hyaluronan create a dismal prognosis

Purpose

Tumor microenvironment, including inflammatory cells, adipocytes and extracellular matrix constituents such as hyaluronan (HA), impacts on cancer progression. Systemic metabolism also influences tumor growth e.g. obesity and type 2 diabetes (T2D) are risk factors for breast cancer. Here, in 262 breast cancer cases, we explored the combined impacts on survival of M2-like tumor associated macrophages (TAMs), the abundance of breast fat visualized as low density in mammograms, and tumor HA, and their associations with T2D.

Methods

Mammographic densities were assessed visually from the diagnostic images and dichotomized into very low density (VLD, density ≤ 10%, “fatty breast”) and mixed density (MID, density > 10%). The amounts of TAMs (CD163+ and CD68+) and tumor HA were determined by immunohistochemistry. The data of T2D was collected from the patient records. Statistical differences between the parameters were calculated with Chi square or Mann–Whitney test and survival analyses with Cox’s model.

Results

A combination of fatty breasts (VLD), abundance of M2-like TAMs (CD163+) and tumor HA associated with poor survival, as survival was 88–89% in the absence of these factors but only 40–47% when all three factors were present (p < 0.001). Also, an association between T2D and fatty breasts was found (p < 0.01). Furthermore, tumors in fatty breasts contained more frequently high levels of M2-like TAMs than tumors in MID breasts (p = 0.01).

Conclusions

Our results demonstrate a dramatic effect of the tumor microenvironment on breast cancer progression. We hypothesize that T2D as well as obesity increase the fat content of the breasts, subsequently enhancing local pro-tumoral inflammation.

Electronic supplementary material

The online version of this article (10.1007/s10549-019-05491-7) contains supplementary material, which is available to authorized users.

Disruption of tumour-associated macrophage trafficking by the osteopontin-induced colony-stimulating factor-1 signalling sensitises hepatocellular carcinoma to anti-PD-L1 blockade

OBJECTIVE

In the tumour microenvironment, critical drivers of immune escape include the oncogenic activity of the tumour cell-intrinsic osteopontin (OPN), the expression of programmed death ligand 1 (PD-L1) and the expansion of tumour-associated macrophages (TAMs). We investigated the feasibility of targeting these pathways as a therapeutic option in hepatocellular carcinoma (HCC) mouse models.

DESIGN

We analysed the number of tumour-infiltrating immune cells and the inflammatory immune profiles in chemically induced liver tumour isolated from wild-type and OPNknockout (KO) mice. In vitro cell cocultures were further conducted to investigate the crosstalk between TAMs and HCC cells mediated by OPN, colony stimulating factor-1 (CSF1) and CSF1 receptor (CSF1R). The in vivo efficacy of anti-PD-L1 and CSF1/CSF1R inhibition was evaluated in OPN overexpressing subcutaneous or orthotopic mouse model of HCC.

RESULTS

The numbers of TAMs, as well as the expression levels of M2 macrophage markers and PD-L1 were significantly decreased, but the levels of cytokines produced by T-helper 1 (Th1) cells were upregulated in tumour tissues from OPN KO mice compared with that from the controls. In addition, we observed a positive association between the OPN and PD-L1 expression, and OPN expression and TAM infiltration in tumour tissues from patients with HCC. We further demonstrated that OPN facilitates chemotactic migration, and alternative activation of macrophages, and promotes the PD-L1 expression in HCC via activation of the CSF1-CSF1R pathway in macrophages. Combining anti-PD-L1 and CSF1R inhibition elicited potent antitumour activity and prolonged survival of OPN^high tumour-bearing mice. Histological, flow cytometric and ELISA revealed increased CD8⁺ T cell infiltration, reduced TAMs and enhanced Th1/Th2 cytokine balance in multiple mouse models of HCC.

CONCLUSIONS

OPN/CSF1/CSF1R axis plays a critical role in the immunosuppressive nature of the HCC microenvironment. Blocking CSF1/CSF1R prevents TAM trafficking and thereby enhances the efficacy of immune checkpoint inhibitors for the treatment of HCC.

Inducible formation of leader cells driven by CD44 switching gives rise to collective invasion and metastases in luminal breast carcinomas

Collective invasion into adjacent tissue is a hallmark of luminal breast cancer, and ~20% of these cases eventually undergo metastasis. How less aggressive luminal-like breast cancer transitions to invasive cancer remains unclear. Our study revealed that CD44^hi cancer cells are the leading subpopulation in collectively invading luminal cancer cells and efficiently promote the collective invasion of CD44^lo/follower cells. The CD44^hi/leader subpopulation showed a specific gene signature of various hybrid epithelial/mesenchymal genes and key functional coregulators of collective invasion, which was distinct from that of CD44^lo/follower cells. However, the CD44^hi/leader cells, which showed a partial epithelial-mesenchymal transition (EMT) phenotype, readily switched to the CD44^lo phenotype along with collective migration and vice versa; this phenomenon was spontaneous and sensitive to the tumor microenvironment. The CD44^lo-to-CD44^hi conversion was accompanied by a shift in CD44s to CD44v but not a conversion of non-cancer stem cells to cancer stem cells (CSCs). Therefore, the CD44^hi leader cells, as currently identified, are not a stable subpopulation in breast tumors. This plasticity and ability to generate CD44^hi carcinoma cells with enhanced migratory and invasive behavior might be responsible for the transition from in situ to invasive behavior of luminal-type breast cancer.

Revisiting the hallmarks of cancer: The role of hyaluronan

Extracellular matrix (ECM) is a complex network of macromolecules such as proteoglycans (PGs), glycosaminoglycans (GAGs) and fibrous proteins present within all tissues and organs. The main role of ECM is not only to provide an essential mechanical scaffold for the cells but also to mediate crucial biochemical cues that are required for tissue homeostasis. Dysregulations in ECM deposition alter cell microenvironment, triggering the onset or the rapid progression of several diseases, including cancer. Hyaluronan (HA) is a ubiquitous component of ECM considered as one of the main players of cancer initiation and progression. This review discusses how HA participate in and regulate several aspects of tumorigenesis, with particular attention to the hallmarks of cancer proposed by Hanahan and Weinberg such as sustaining of the proliferative signaling, evasion of apoptosis, angiogenesis, activation of invasion and metastases, reprogramming of energy metabolism and evasion of immune response.

Hyaluronan preconditioning of monocytes/macrophages affects their angiogenic behavior and regulation of TSG-6 expression in a tumor type-specific manner

Hyaluronan is a glycosaminoglycan normally present in the extracellular matrix in most tissues. Hyaluronan is a crucial player in many processes associated with cancer, such as angiogenesis, invasion, and metastasis. However, little has been reported regarding the action of hyaluronan on monocytes/macrophages (Mo/MØ) in tumor angiogenesis and its consequences on tumor development. In the present study, we investigated the effects of hyaluronan of different sizes on human Mo/MØ angiogenic behavior in colorectal and breast carcinoma. In vitro, the treatment of Mo/MØ with lysates and conditioned media from a breast but not from colorectal carcinoma cell line plus high-molecular weight hyaluronan induced: (a) an increased expression of angiogenic factors VEGF, IL-8, FGF-2, and MMP-2, (b) an increased endothelial cell migration, and (c) a differential expression of hyaluronan-binding protein TSG-6. Similar results were observed in Mo/MØ derived from breast cancer patients treated with tumor lysates. Besides, macrophages primed with high-molecular weight hyaluronan and inoculated in human breast cancer xenograft tumor increased blood vessel formation and diminished TSG-6 levels. In contrast, the effects triggered by high-molecular weight hyaluronan on Mo/MØ in breast cancer context were not observed in the context of colorectal carcinoma. Taken together, these results indicate that the effect of high-molecular weight hyaluronan as an inductor of the angiogenic behavior of macrophages in breast tumor context is in part consequence of the presence of TSG-6.

Colorectal cancer-associated ~ 6 kDa hyaluronan serves as a novel biomarker for cancer progression and metastasis

Low molecular weight hyaluronan (LMW-HA) is believed to accumulate in tumors and to exert protumor effects. This study aimed to identify colorectal cancer (CRC)-associated LMW-HA, precisely determine its MW, and elucidate its role in predicting tumor progression. The MW distribution of HA extracted from CRC and paired noncancerous tissues was evaluated. We found that the level of HA with a MW below 30 kDa was markedly elevated in CRC tissues, and we defined HA with a MW of ~ 6 kDa as CRC-associated LMW-HA. In line with this finding, ~ 6 kDa HA was significantly accumulated in cancer tissues relative to total HA, and this LMW-HA played a critical role in tumor metastasis. Moreover, serum ~ 6 kDa HA levels in CRC patients were significantly increased and positively correlated with the levels in matched cancer tissues. Elevated serum ~ 6 kDa HA levels could be used to discriminate patients with or without CRC and was associated with early relapse, advanced tumor-node-metastasis stage, lymphovascular invasion, and lymph node (LN) metastasis. Notably, serum ~ 6 kDa HA levels were significantly reduced after tumor resection. Our study suggests that ~ 6 kDa HA may serve as a new biomarker for estimating tumor progression, predicting LN metastasis, and monitoring tumor recurrence.

INT-HA induces M2-like macrophage differentiation of human monocytes via TLR4-miR-935 pathway

As a major component of the microenvironment of solid tumors, tumor-associated macrophages (TAMs) facilitate tumor progression. Intermediate-sized hyaluronan (INT-HA) fragments have an immunological function in cell differentiation; however, their role in promoting the polarization of non-activated macrophages to an M2-like TAM phenotype has not been characterized, and the underlying mechanisms remain unclear. Here, we used a miRNA microarray to find that some miRNAs (especially miR-935) were differentially regulated in INT-HA-induced M2-like macrophages. According to RT-qPCR and Western blot, there was an association between miR-935 and C/EBPβ, that control the polarization of macrophages. Moreover, we found that INT-HA induced an M2-like phenotype via the TLR4 receptor. In our study, there was a negative correlation between plasma HA and miR-935 in monocytes from the peripheral blood of patients with solid tumors. There was also a negative correlation between miR-935 and M2-like macrophage markers in monocytes. These findings suggest that HA fragments interact with TLR4 and educate macrophage polarization to an M2-like phenotype via miR-935. Therefore, this study provides new insight into the role of miR-935 in INT-HA-induced M2-like polarization, and suggests a potential therapeutic target for antitumor treatment.

Hydroxychloroquine induced lung cancer suppression by enhancing chemo-sensitization and promoting the transition of M2-TAMs to M1-like macrophages

BACKGROUND

Lysosome-associated agents have been implicated as possible chemo-sensitizers and immune regulators for cancer chemotherapy. We investigated the potential roles and mechanisms of hydroxychloroquine (HCQ) in combination with chemotherapy in lung cancer treatment.

METHODS

The effects of combined treatment on non-small cell lung cancer (NSCLC) were investigated using cell viability assays and animal models. The influence of HCQ on lysosomal pH was evaluated by lysosomal sensors and confocal microscopy. The effects of HCQ on the tumour immune microenvironment were analysed by flow cytometry.

RESULTS

HCQ elevates the lysosomal pH of cancer cells to inactivate P-gp while increasing drug release from the lysosome into the nucleus. Furthermore, single HCQ therapy inhibits lung cancer by inducing macrophage-modulated anti-tumour CD8⁺ T cell immunity. Moreover, HCQ could promote the transition of M2 tumour-associated macrophages (TAMs) into M1-like macrophages, leading to CD8⁺ T cell infiltration into the tumour microenvironment.

CONCLUSIONS

HCQ exerts anti-NSCLC cells effects by reversing the drug sequestration in lysosomes and enhancing the CD8⁺ T cell immune response. These findings suggest that HCQ could act as a promising chemo-sensitizer and immune regulator for lung cancer chemotherapy in the clinic.

Tumor-associated macrophages recruited by periostin in intrahepatic cholangiocarcinoma stem cells

Periostin (POSTN) secreted by intrahepatic cholangiocarcinoma stem cells (ICSCs) serves important roles in promoting tumor progression. The present study aimed to investigate POSTN-recruited tumor-associated macrophages (TAMs) in intrahepatic cholangiocarcinoma (ICC). A total of 50 cases were used to investigate the distribution of ICSCs and TAMs in ICC. HCCC-9810 cells were sorted by cluster of differentiation (CD)44, the expression of POSTN of CD44⁺ (cancer stem cells) and CD44^- cells (non-cancer stem cells), and medium were evaluated by western blot analysis. HCCC-9810 cells and THP-1 macrophages were used to detect the effects of POSTN on recruiting TAMs in vitro. The present study revealed that CD44⁺ cells in ICC tissues and the HCCC-9810 cell line were associated with high POSTN secretion levels. Furthermore, POSTN was associated with TAM density in primary ICC tissues. Additionally, POSTN increased the migration of TAMs derived from THP-1 cells. These findings suggested that POSTN secreted by ICSCs may serve important functions in TAM recruitment, and it may be a potential curative strategy to target the tumor microenvironment in ICC.

Combination of plasma HA and circulating M2-like monocytes may serve as a diagnostic marker for breast cancer

Background: Breast cancer (BC)-derived hyaluronan (HA) can induce the formation of M2-like tumor-associated macrophages (TAMs) in tumor context. However, little is known about the correlation between circulating M2-like monocytes and plasma HA in BC patients. This study focused on evaluating the relationship between circulating M2-like monocytes and plasma HA, and further appraised the diagnostic value of them in BC.

Methods: The expression of M2-like TAMs and HA was determined in pathological tissues by immunohistochemistry. Flow cytometry was used to detect the levels of circulating CD14⁺CD204⁺ M2-like monocytes in 81 BC patients, 45 patients with breast benign diseases, and 46 healthy subjects. The levels of HA, CEA, and CA15-3 were measured in plasma samples using chemiluminescence method.

Results: M2-like TAMs and HA expressions were elevated in BC tissues compared with benign tissues. In correspondence, the frequency of circulating CD14⁺CD204⁺ M2-like monocytes and the plasma HA levels were significantly higher in patients with BC than those in control groups. Importantly, there was a positive correlation between circulating M2-like monocytes and the plasma HA (Spearman r = 0.404, p < 0.001). Area under receiver operating characteristic curve (ROC) for the combination of circulating M2-like monocytes and HA was 0.899 (95% CI: 0.853-0.946), which was higher than the panel of CEA and CA15-3.

Conclusions: The frequency of circulating CD14⁺CD204⁺ M2-like monocytes was positively correlated to plasma HA levels. The combination of circulating CD14⁺CD204⁺ M2-like monocytes and plasma HA could provide considerable diagnostic value in BC.

High density of CD204-positive macrophages predicts worse clinical prognosis in patients with breast cancer

Recent studies have indicated the clinical significance of tumor‐associated macrophages (TAM) in several malignant tumors including breast cancer. Although recent studies have focused on CD68‐positive or CD163‐positive TAM in breast cancer, no study has investigated the significance of CD204‐positive TAM in breast cancer. We found that CD204 expression on macrophages was evaluated following stimulation with the conditioned medium (CM) of breast cancer cell lines. Paraffin sections of 149 breast cancer samples which were diagnosed as invasive ductal carcinoma were immunohistochemically analyzed for CD68, CD163 and CD204 expression. The results of analyses indicated that a high number of CD204‐positive TAM was associated with worse clinical prognoses, including relapse‐free survival, distant relapse‐free survival and breast cancer‐specific survival; however, neither the numbers of CD68‐positive or CD163‐positive TAM were associated with clinical courses. Of the clinicopathological factors investigated, estrogen receptor, Ki‐67 index, hormone subtype, and histological grade were significantly related to the increased number of CD163‐positive and CD204‐positive TAM. These data indicate the clinical significance of CD204‐positive TAM in breast cancer progression and CD204 is a marker for predicting clinical prognosis in breast cancer.

LncRNA-MALAT1 Promotes Angiogenesis of Thyroid Cancer by Modulating Tumor-Associated Macrophage FGF2 Protein Secretion

Tumor-associated macrophages (TAMs) in the tumor microenvironment have been associated with enhanced tumor progression. In this study, we investigated the role and molecular mechanisms of MALAT1 in TAMs derived from thyroid cancer. The expression of MALAT1 and FGF2 in thyroid cancer tissues and cells were measured by quantitative real-time PCR and Western blot. TAMs were transfected with indicated constructs. Then the culture medium (CM) from TAMs was harvested for assay. Secreted FGF2 protein levels and TNF-α, IL-12, and IL-10 levels were detected by ELISA. The cell proliferation, migration, and invasion of FTC133 cells were determined with a CCK-8 assay and a Transwell assay, respectively. In addition, HUVEC vasculature formation was measured by matrigel angiogenesis assay. The higher levels of MALAT-1 and FGF2 were observed in thyroid cancer tissues and in thyroid cancer cells compared to that in the control. Besides, in the presence of si-MALAT1, the levels of TNF-α and IL-12 were significantly up-regulated whereas IL-10 was down-regulated in the CM from TAMs. Moreover, down-regulation of MALAT1 in TAMs reduced proliferation, migration, and invasion of FTC133 cells and inhibited angiogenesis. However, overexpression of FGF2 blocked the effects of MALAT1 siRNAs on cell migration, invasion, and angiogenesis. Our results suggest that MALAT1-mediated FGF2 protein secretion from TAMs inhibits inflammatory cytokines release, promotes proliferation, migration, and invasion of FTC133 cells and induces vasculature formation. J. Cell. Biochem. 118: 4821-4830, 2017. © 2017 Wiley Periodicals, Inc.