Dual Immunostimulatory Pathway Agonism through a Synthetic Nanocarrier Triggers Robust Anti-Tumor Immunity in Murine Glioblastoma

Breaking the barriers in effective and safe Toll-like receptor stimulation via nano-immunomodulators for potent cancer immunotherapy

Immunotherapy is an emerging strategy that awakens the intrinsic immune system for cancer treatment. Generally, successful immunotherapy of malignant tumours relies on the effective production of tumour-associated antigens and their lymph node delivery, antigen processing and presentation for T-cell activation, and the dismantling of the immunosuppressive tumour microenvironment. Toll-like receptor (TLR) agonists are potent stimulants in cancer immunotherapy, which can directly activate antigen-presenting cells (APCs) and further induce T cell activation for antitumour immune response and convert immunosuppressive tumour microenvironment to an immunogenic one for cooperative tumour ablation. However, TLR agonists for effective cancer immunotherapy have encountered essential challenges, such as insufficient immune activation and systemic side effects. In recent years, nano-immunomodulators with TLR agonists have been employed for tumour- and/or lymph node-targeted immune activation to improve the antitumour immune response and alleviate their systemic toxicities, providing a promising strategy for enhanced cancer immunotherapy. Herein, we introduce the recent progress in developing various TLR nano-immunomodulators for cancer immunotherapy via APC activation and tumour microenvironment remodelling. Upon elucidating the rational design principles of nano-immunomodulators, we elucidate the advancement of TLR nanoagonists to break the barriers in effective and safe Toll-like receptor stimulation for potent cancer immunotherapy.

Genetically Engineered IL12/CSF1R-Macrophage Membrane-Liposome Hybrid Nanovesicles for NIR-II Fluorescence Imaging-Guided and Membrane-Targeted Mild Photothermal-Immunotherapy of Glioblastoma

It is a big challenge for precision therapy of glioblastoma, mainly due to the existence of blood-brain barrier (BBB), tumor immunosuppressive microenvironment (TIM), and lack of efficient treatment paradigms. Herein, a theranostic nanoplatform for the second near-infrared window (NIR-II) fluorescence imaging-guided membrane-targeted mild photothermal-immunotherapy of glioblastoma using genetically engineered CSF1R/IL12-macrophage membrane (MM)-liposome hybrid nanovesicles, is reported. By mimicking lipophilic membrane probe (Dil) with octadecyl chains, a NIR-II emissive photothermal dye (IRC18), which realizes labeling of nanovesicle lipid bilayers for biodistribution tracing, glioblastoma diagnosis, and molecular imaging of tumoral microenvironment, is synthesized. Importantly, MM and c-RGD-decorated liposome together offer BBB crossing, tumor targeting, and long-term circulation; while, the genetically overexpressed CSF1R and IL12 on MM surface contribute to effective modulation of M2-to-M1 macrophage repolarization and local promotion of T cell cytotoxicity in glioblastoma microenvironment, respectively. Notably, through membrane fusion, IRC18 dyes translocate from nanovesicle lipid bilayers to glioblastoma membranes, which achieve membrane-targeted mild photothermal therapy to ablate primary tumor and induce immunogenic cell death to promote antigen presentation. More importantly, the combined blockade of the CSF1-CSF1R axis and IL-12 enrichment not only reprograms the tumor microenvironment through macrophage M1 repolarization but also activates cytotoxic T cells, ultimately achieving complete glioblastoma eradication. This research provides an efficient theranostic paradigm for glioblastoma treatment.

Fluorinated Ribonucleocarbohydrate Nanoparticles Allow Ultraefficient mRNA Delivery and Protein Expression in Tumor-Associated Myeloid Cells

Ribonucleic acids (RNA) are commonly formulated into lipid nanoparticles (LNP) for in vivo use, but challenges exist with systemic delivery and low in vivo expression efficiency. Inspired by ribonucleoprotein complexes in cells, we created synthetic ribonucleocarbohydrate (RNC) complexes based on cyclodextrin nanoparticles with ferrocenyl fluorocarbons capable of carrying mRNA and additional small-molecule drug payloads, facilitating lysosomal escape and immune stimulation all in the same nanoparticle. We show that this strategy results in highly efficient myeloid cell targeting (dendritic cells and MHC expressing macrophages) and protein expression following systemic administration. The RNC platform should have broad applications in vaccine development, immunosuppression, and immunostimulation for various diseases.

For and against tumor microenvironment: Nanoparticle-based strategies for active cancer therapy

Cancer treatment is challenged by the tumor microenvironment (TME), which promotes drug resistance and cancer cell growth. This review offers a comprehensive and innovative perspective on how nanomedicine can modify the TME to enhance therapy. Strategies include using nanoparticles to improve oxygenation, adjust acidity, and alter the extracellular matrix, making treatments more effective. Additionally, nanoparticles can enhance immune responses by activating immune cells and reducing suppression within tumors. By integrating these approaches with existing therapies, such as chemotherapy and radiotherapy, nanoparticles show promise in overcoming traditional treatment barriers. The review discusses how changes in the TME can enhance the effectiveness of nanomedicine itself, creating a reciprocal relationship that boosts overall efficacy. We also highlight novel strategies aimed at exploiting and overcoming the TME, leveraging nanoparticle-based approaches for targeted cancer therapy through precise TME modulation.

Recent developments in myeloid immune modulation in cancer therapy

Myeloid cells play a crucial dual role in cancer progression and response to therapy, promoting tumor growth, enabling immune suppression, and contributing to metastatic spread. The ability of these cells to modulate the immune system has made them attractive targets for therapeutic strategies aimed at shifting their function from tumor promotion to fostering antitumor immunity. Therapeutic approaches targeting myeloid cells focus on modifying their numbers, genetics, metabolism, and interactions within the tumor microenvironment. These strategies aim to reverse their suppressive functions and redirect them to support antitumor immune responses by inhibiting immunosuppressive pathways, targeting specific receptors, and promoting their differentiation into less immunosuppressive phenotypes. Here, we discuss recent approaches to clinically target tumor myeloid cells, focusing on reprogramming myeloid cells to promote antitumor immunity.

NetSDR: Drug repurposing for cancers based on subtype-specific network modularization and perturbation analysis

Cancer, a heterogeneous disease, presents significant challenges for drug development due to its complex etiology. Drug repurposing, particularly through network medicine approaches, offers a promising avenue for cancer treatment by analyzing how drugs influence cellular networks on a systemic scale. The advent of large-scale proteomics data provides new opportunities to elucidate regulatory mechanisms specific to cancer subtypes. Herein, we present NetSDR, a Network-based Subtype-specific Drug Repurposing framework for prioritizing repurposed drugs specific to certain cancer subtypes, guided by subtype-specific proteomic signatures and network perturbations. First, by integrating cancer subtype information into a network-based method, we developed a pipeline to recognize subtype-specific functional modules. Next, we conducted drug response analysis for each module to identify the "therapeutic module" and then used deep learning to construct weighted drug response network for the particular subtype. Finally, we employed a perturbation response scanning-based drug repurposing method, which incorporates dynamic information, to facilitate the prioritization of candidate drugs. Applying the framework to gastric cancer, we attested the significance of the extracellular matrix module in treatment strategies and discovered a promising potential drug target, LAMB2, as well as a series of possible repurposed drugs. This study demonstrates a systems biology framework for precise drug repurposing in cancer and other complex diseases.

Exosomes in the Chemoresistance of Glioma: Key Point in Chemoresistance

Gliomas are the most ordinary primary virulent brain tumours and commonly used clinical treatments include tumour resection, radiation therapy and chemotherapy. Although significant progress has been made in recent years in progression-free survival (PFS) and overall survival (OS) for patients with high-grade gliomas, the prognosis for patients remains poor. Chemoresistance refers to the phenomenon of decreased sensitivity of tumour cells to drugs, resulting in reduced or ineffective drug efficacy, and is an important cause of failure of tumour chemotherapy. Exosomes, a type of extracellular vesicle, are secreted by cancer cells and various stromal cells in the tumour microenvironment (TME) and transfer their inclusions to cancer cells, increasing chemoresistance. Furthermore, depletion of exosomes reverses certain detrimental effects on tumour metabolism and restores sensitivity to chemotherapeutic agents. Here, we summarised the correlation between exosomes and resistance to chemotherapeutic agents in glioma patients, the mechanisms of action of exosomes involved in resistance and their clinical value. We aimed to afford new thoughts for research, clinical diagnosis and intervention in the mechanisms of chemoresistance in glioma patients.

Peptide-drug conjugates repolarize glioblastoma-associated macrophages to resensitize chemo-immunotherapy of glioblastoma

The prevalent tumor-supporting glioblastoma-associated macrophages (GAMs) promote glioblastoma multiforme (GBM) progression and resistance to multiple therapies. Repolarizing GAMs from tumor-supporting to tumor-inhibiting phenotype may troubleshoot. However, sufficient accumulation of drugs at the GBM site is restricted by blood-brain barrier (BBB). Herein, we designed peptide-drug conjugates (PDCs) by conjugating camptothecin or resiquimod to a tandem peptide composed of matrix metalloproteinase 2-responsive peptide and angiopep-2 via disulfonyl-ethyl carbonate/carbamate (MAPDCs). The mixed self-assembly MAPDCs could recognize low-density lipoprotein receptor-related protein 1 (LRP1) to facilitate BBB transport. Once reaching the GBM site, the responsive peptide would be cleaved to shed the angiopep-2, blocking abluminal LRP1-mediated brain-to-blood efflux and enhancing drug retention. Sequentially, drugs are released under the high level of intracellular glutathione. In vivo studies demonstrated that MAPDCs repolarized GAMs, boosted immune response, and resensitized chemotherapeutic toxicity, offering a much-improved anti-GBM effect. The effectiveness of MAPDCs validates GAMs as therapeutic target and PDCs as versatile brain delivery system with high design flexibility.

Long non-coding RNA OIP5-AS1 protects neurons from ischemia-reperfusion injury and inhibits neuronal apoptosis through TAB-2

Ischemic stroke represents a highly perilous cerebrovascular disorder, involving a variety of complex pathophysiological mechanisms. OIP5 antisense RNA 1 (OIP5-AS1) is a long non-coding RNA (LncRNA) that has been shown to play a pivotal role in a variety of disease systems. However, there are relatively few studies on ischemic stroke. This research aimed to elucidate the direct impact of OIP5-AS1 on neuronal cells following cerebral ischemia-reperfusion. Our study revealed a significant reduction in OIP5-AS1 expression in mouse neurons following middle cerebral artery occlusion/reperfusion (MCAO/R). Overexpression of OIP5-AS1 in neurons inhibits neuronal apoptosis induced by cerebral ischemia-reperfusion injury (CIRI) and exerts a neuroprotective role. Mechanistically, OIP5-AS1 may play a neuroprotective role after CIRI by up-regulating the expression of TAK1 binding protein 2 (TAB-2), reducing neuronal mitochondrial damage, and inhibiting apoptosis. OIP5-AS1 may become a novel therapeutic target for ischemic stroke.

Targeted SPP1 Inhibition of Tumor-Associated Myeloid Cells Effectively Decreases Tumor Sizes

Secreted phosphosprotein 1 (SPP1)High tumor-associated macrophages (TAM) are abundant tumor myeloid cells that are immunosuppressive, pro-tumorigenic, and have a highly negative prognostic factor. Despite this, there is a lack of efficient TAM-specific therapeutics capable of reducing SPP1 expression. Here, on a phenotypic screen is reported to identify small molecule SPP1 modulators in macrophages. Several hits and incorporated them into a TAM-avid systemic nanoformulation are identified. It is shown that the lead compound (CANDI460) can down-regulate SPP1 in vitro and in vivo and lead to tumor remissions in different murine models. These findings are important as they offer a promising avenue for developing novel therapeutic strategies targeting TAM.

Reshaped Local and Systemic Immune Responses Triggered by a Biomimetic Multifunctional Nanoplatform Coordinating Multi-Pathways for Cancer Therapy

Immunotherapy has fundamentally transformed the clinical cancer treatment landscape; however, achieving intricate and multifaceted modulation of the immune systems remains challenging. Here, a multipathway coordination of immunogenic cell death (ICD), autophagy, and indoleamine 2,3-dioxygenase-1 (IDO1) was achieved by a biomimetic nano-immunomodulator assembled from a chemotherapeutic agent (doxorubicin, DOX), small interfering RNA (siRNA) molecules targeting IDO1 (siIDO1), and the zeolitic imidazolate framework-8 (ZIF-8). After being camouflaged with a macrophage membrane, the biomimetic nanosystem, named mRDZ, enriched in tumors, which allowed synergistic actions of its components within tumor cells. The chemotherapeutic intervention led to a compensatory upregulation in the expression of IDO1, consequently exerting an inhibitory effect on the reactive oxygen species (ROS) and autophagic responses triggered by DOX and ZIF-8. Precise gene silencing of IDO1 by siIDO1 alleviated its suppressive influence, thereby facilitating increased ROS production and improved autophagy, ultimately bolstering tumor immunogenicity. mRDZ exhibited strong capability to boost potent local and systemic antitumor immune responses with a feature of memory, which led to the effective suppression of the growth, lung metastasis, and recurrence of the tumor. Serving as an exemplary model for the straightforward and potent reshaping of the immune system against tumors, mRDZ offers valuable insights into the development of immunomodulatory nanomaterials for cancer therapy.

Applications of nanotechnology in remodeling the tumour microenvironment for glioblastoma treatment

With the increasing research and deepening understanding of the glioblastoma (GBM) tumour microenvironment (TME), novel and more effective therapeutic strategies have been proposed. The GBM TME involves intricate interactions between tumour and non-tumour cells, promoting tumour progression. Key therapeutic goals for GBM treatment include improving the immunosuppressive microenvironment, enhancing the cytotoxicity of immune cells against tumours, and inhibiting tumour growth and proliferation. Consequently, remodeling the GBM TME using nanotechnology has emerged as a promising approach. Nanoparticle-based drug delivery enables targeted delivery, thereby improving treatment specificity, facilitating combination therapies, and optimizing drug metabolism. This review provides an overview of the GBM TME and discusses the methods of remodeling the GBM TME using nanotechnology. Specifically, it explores the application of nanotechnology in ameliorating immune cell immunosuppression, inducing immunogenic cell death, stimulating, and recruiting immune cells, regulating tumour metabolism, and modulating the crosstalk between tumours and other cells.

Stemness, invasion, and immunosuppression modulation in recurrent glioblastoma using nanotherapy

The recurrent nature of glioblastoma negatively impacts conventional treatment strategies leading to a growing need for nanomedicine. Nanotherapeutics, an approach designed to deliver drugs to specific sites, is experiencing rapid growth and gaining immense popularity. Having potential in reaching the hard-to-reach disease sites, this field has the potential to show high efficacy in combatting glioblastoma progression. The presence of glioblastoma stem cells (GSCs) is a major factor behind the poor prognosis of glioblastoma multiforme (GBM). Stemness potential, heterogeneity, and self-renewal capacity, are some of the properties that make GSCs invade across the distant regions of the brain. Despite advances in medical technology and MRI-guided maximal surgical resection, not all GSCs residing in the brain can be removed, leading to recurrent disease. The aggressiveness of GBM is often correlated with immune suppression, where the T-cells are unable to infiltrate the cancer initiating GSCs. Standard of care therapies, including surgery and chemotherapy in combination with radiation therapy, have failed to tackle all the challenges of the GSCs, making it increasingly important for researchers to develop strategies to tackle their growth and proliferation and reduce the recurrence of GBM. Here, we will focus on the advancements in the field of nanomedicine that has the potential to show positive impact in managing glioblastoma tumor microenvironment. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

A non-lipid nucleic acid delivery vector with dendritic cell tropism and stimulation

Rationale: Nucleic acid constructs are commonly used for vaccination, immune stimulation, and gene therapy, but their use in cancer still remains limited. One of the reasons is that systemic delivery to tumor-associated antigen-presenting cells (dendritic cells and macrophages) is often inefficient, while off-target nucleic acid-sensing immune pathways can stimulate systemic immune responses. Conversely, certain carbohydrate nanoparticles with small molecule payloads have been shown to target these cells efficiently in the tumor microenvironment. Yet, nucleic acid incorporation into such carbohydrate-based nanoparticles has proven challenging. Methods: We developed a novel approach using cross-linked bis succinyl-cyclodextrin (b-s-CD) nanoparticles to efficiently deliver nucleic acids and small-molecule immune enhancer to phagocytic cells in tumor environments and lymph nodes. Our study involved incorporating these components into the nanoparticles and assessing their efficacy in activating antigen-presenting cells. Results: The multi-modality immune stimulators effectively activated antigen-presenting cells and promoted anti-tumor immunity in vivo. This was evidenced by enhanced delivery to phagocytic cells and subsequent immune response activation in tumor environments and lymph nodes. Conclusion: Here, we describe a new approach to incorporating both nucleic acids and small-molecule immune enhancers into cross-linked bis succinyl-cyclodextrin (b-s-CD) nanoparticles for efficient delivery to phagocytic cells in tumor environments and lymph nodes in vivo. These multi-modality immune stimulators can activate antigen-presenting cells and foster anti-tumor immunity. We argue that this strategy can potentially be used to enhance anti-tumor efficacy.

Pharmacological Polarization of Tumor-Associated Macrophages Toward a CXCL9 Antitumor Phenotype

Tumor-associated macrophages (TAM) are a diverse population of myeloid cells that are often abundant and immunosuppressive in human cancers. CXCL9Hi TAM has recently been described to have an antitumor phenotype and is linked to immune checkpoint response. Despite the emerging understanding of the unique antitumor TAM phenotype, there is a lack of TAM-specific therapeutics to exploit this new biological understanding. Here, the discovery and characterization of multiple small-molecule enhancers of chemokine ligand 9 (CXCL9) and their targeted delivery in a TAM-avid systemic nanoformulation is reported. With this strategy, it is efficient encapsulation and release of multiple drug loads that can efficiently induce CXCL9 expression in macrophages, both in vitro and in vivo in a mouse tumor model. These observations provide a window into the molecular features that define TAM-specific states, an insight a novel therapeutic anticancer approach is used to discover.

Host-functionalization of macrin nanoparticles to enable drug loading and control tumor-associated macrophage phenotype

Macrophages are critical regulators of the tumor microenvironment and often present an immuno-suppressive phenotype, supporting tumor growth and immune evasion. Promoting a robust pro-inflammatory macrophage phenotype has emerged as a therapeutic modality that supports tumor clearance, including through synergy with immune checkpoint therapies. Polyglucose nanoparticles (macrins), which possess high macrophage affinity, are useful vehicles for delivering drugs to macrophages, potentially altering their phenotype. Here, we examine the potential of functionalized macrins, synthesized by crosslinking carboxymethyl dextran with L-lysine, as effective carriers of immuno-stimulatory drugs to tumor-associated macrophages (TAMs). Azide groups incorporated during particle synthesis provided a handle for click-coupling of propargyl-modified β-cyclodextrin to macrins under mild conditions. Fluorescence-based competitive binding assays revealed the ability of β-cyclodextrin to non-covalently bind to hydrophobic immuno-stimulatory drug candidates (Keq ~ 103 M-1), enabling drug loading within nanoparticles. Furthermore, transcriptional profiles of macrophages indicated robust pro-inflammatory reprogramming (elevated Nos2 and Il12; suppressed Arg1 and Mrc1 expression levels) for a subset of these immuno-stimulatory agents (UNC2025 and R848). Loading of R848 into the modified macrins improved the drug's effect on primary murine macrophages by three-fold in vitro. Intravital microscopy in IL-12-eYFP reporter mice (24 h post-injection) revealed a two-fold enhancement in mean YFP fluorescence intensity in macrophages targeted with R848-loaded macrins, relative to vehicle controls, validating the desired pro-inflammatory reprogramming of TAMs in vivo by cell-targeted drug delivery. Finally, in an intradermal MC38 tumor model, cyclodextrin-modified macrin NPs loaded with immunostimulatory drugs significantly reduced tumor growth. Therefore, efficient and effective repolarization of tumor-associated macrophages to an M1-like phenotype-via drug-loaded macrins-inhibits tumor growth and may be useful as an adjuvant to existing immune checkpoint therapies.

Cellular Components of the Tumor Environment in Gliomas-What Do We Know Today?

A generation ago, the molecular properties of tumor cells were the focus of scientific interest in oncology research. Since then, it has become increasingly apparent that the tumor environment (TEM), whose major components are non-neoplastic cell types, is also of utmost importance for our understanding of tumor growth, maintenance and resistance. In this review, we present the current knowledge concerning all cellular components within the TEM in gliomas, focusing on their molecular properties, expression patterns and influence on the biological behavior of gliomas. Insight into the TEM of gliomas has expanded considerably in recent years, including many aspects that previously received only marginal attention, such as the phenomenon of phagocytosis of glioma cells by macrophages and the role of the thyroid-stimulating hormone on glioma growth. We also discuss other topics such as the migration of lymphocytes into the tumor, phenotypic similarities between chemoresistant glioma cells and stem cells, and new clinical approaches with immunotherapies involving the cells of TEM.

Perfusion Window Chambers Enable Interventional Analyses of Tumor Microenvironments

Intravital microscopy (IVM) allows spatial and temporal imaging of different cell types in intact live tissue microenvironments. IVM has played a critical role in understanding cancer biology, invasion, metastases, and drug development. One considerable impediment to the field is the inability to interrogate the tumor microenvironment and its communication cascades during disease progression and therapeutic interventions. Here, a new implantable perfusion window chamber (PWC) is described that allows high-fidelity in vivo microscopy, local administration of stains and drugs, and longitudinal sampling of tumor interstitial fluid. This study shows that the new PWC design allows cyclic multiplexed imaging in vivo, imaging of drug action, and sampling of tumor-shed materials. The PWC will be broadly useful as a novel perturbable in vivo system for deciphering biology in complex microenvironments.

Hybrid LNP Prime Dendritic Cells for Nucleotide Delivery

The efficient activation of professional antigen-presenting cells-such as dendritic cells (DC)-in tumors and lymph nodes is critical for the design of next-generation cancer vaccines and may be able to provide anti-tumor effects by itself through immune stimulation. The challenge is to stimulate these cells without causing excessive toxicity. It is hypothesized that a multi-pronged combinatorial approach to DC stimulation would allow dose reductions of innate immune receptor-stimulating TLR3 agonists while enhancing drug efficacy. Here, a hybrid lipid nanoparticle (LNP) platform is developed and tested for double-stranded RNA (polyinosinic:polycytidylic acid for TLR3 agonism) and immune modulator (L-CANDI) delivery. This study shows that the ≈120 nm hybrid nanoparticles-in-nanoparticles effectively eradicate tumors by themselves and generate long-lasting, durable anti-tumor immunity in mouse models.

Highly Active Myeloid Therapy for Cancer

Tumor-associated macrophages (TAM) interact with cancer and stromal cells and are integral to sustaining many cancer-promoting features. Therapeutic manipulation of TAM could therefore improve clinical outcomes and synergize with immunotherapy and other cancer therapies. While different nanocarriers have been used to target TAM, a knowledge gap exists on which TAM pathways to target and what payloads to deliver for optimal antitumor effects. We hypothesized that a multipart combination involving the Janus tyrosine kinase (JAK), noncanonical nuclear factor kappa light chain enhancer of activated B cells (NF-κB), and toll-like receptor (TLR) pathways could lead to a highly active myeloid therapy (HAMT). Thus, we devised a screen to determine drug combinations that yield maximum IL-12 production from myeloid cells to treat the otherwise highly immunosuppressive myeloid environments in tumors. Here we show the extraordinary efficacy of a triple small-molecule combination in a TAM-targeted nanoparticle for eradicating murine tumors, jumpstarting a highly efficient antitumor response by adopting a distinctive antitumor TAM phenotype and synergizing with other immunotherapies. The HAMT therapy represents a recently developed approach in immunotherapy and leads to durable responses in murine cancer models.

Dendritic cells as shepherds of T cell immunity in cancer

In cancer patients, dendritic cells (DCs) in tumor-draining lymph nodes can present antigens to naive T cells in ways that break immunological tolerance. The clonally expanded progeny of primed T cells are further regulated by DCs at tumor sites. Intratumoral DCs can both provide survival signals to and drive effector differentiation of incoming T cells, thereby locally enhancing antitumor immunity; however, the paucity of intratumoral DCs or their expression of immunoregulatory molecules often limits antitumor T cell responses. Here, we review the current understanding of DC-T cell interactions at both priming and effector sites of immune responses. We place emerging insights into DC functions in tumor immunity in the context of DC development, ontogeny, and functions in other settings and propose that DCs control at least two T cell-associated checkpoints of the cancer immunity cycle. Our understanding of both checkpoints has implications for the development of new approaches to cancer immunotherapy.