Natural Products for the Immunotherapy of Glioma

Immunosuppressive MDSC and Treg signatures predict prognosis and therapeutic response in glioma

Glioma, a complex and aggressive brain tumor, is characterized by dysregulated immune responses within the tumor microenvironment (TME). We conducted a comprehensive analysis to elucidate the roles of myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs) in glioma progression and their impact on the immune landscape. Using transcriptome data, we stratified glioma samples based on MDSC and Treg levels, revealing significant differences in patient survival probabilities. LASSO regression identified a gene panel associated with glioma prognosis, yielding a patient-specific risk score. Multivariate Cox regression confirmed the risk score's correlation with overall survival. An ISS (immune suppressive score) system assessed the immune landscape's impact on glioma progression and therapeutic response. Functional validation showed MDSC and Treg infiltration's relevance in glioma progression and immune modulation. Hub genes in the black module, including CCL2, LINC01503, CXCL8, CLEC2B, TIMP1, and RGS2, were identified through MCODE analysis. RGS2 expression correlated with immune cell populations and varied in glioma cells. This study sheds light on MDSCs' and Tregs' roles in glioma pathogenesis, suggesting their potential as prognostic biomarkers and therapeutic targets for personalized immunotherapeutic strategies in glioma treatment.

Natural Products from Herbal Medicine Self-Assemble into Advanced Bioactive Materials

Novel biomaterials are becoming more crucial in treating human diseases. However, many materials require complex artificial modifications and synthesis, leading to potential difficulties in preparation, side effects, and clinical translation. Recently, significant progress has been achieved in terms of direct self-assembly of natural products from herbal medicine (NPHM), an important source for novel medications, resulting in a wide range of bioactive supramolecular materials including gels, and nanoparticles. The NPHM-based supramolecular bioactive materials are produced from renewable resources, are simple to prepare, and have demonstrated multi-functionality including slow-release, smart-responsive release, and especially possess powerful biological effects to treat various diseases. In this review, NPHM-based supramolecular bioactive materials have been revealed as an emerging, revolutionary, and promising strategy. The development, advantages, and limitations of NPHM, as well as the advantageous position of NPHM-based materials, are first reviewed. Subsequently, a systematic and comprehensive analysis of the self-assembly strategies specific to seven major classes of NPHM is highlighted. Insights into the influence of NPHM structural features on the formation of supramolecular materials are also provided. Finally, the drivers and preparations are summarized, emphasizing the biomedical applications, future scientific challenges, and opportunities, with the hope of igniting inspiration for future research and applications.

Insights of immune cell heterogeneity, tumor-initiated subtype transformation, drug resistance, treatment and detecting technologies in glioma microenvironment

BACKGROUND

With the gradual understanding of glioma development and the immune microenvironment, many immune cells have been discovered. Despite the growing comprehension of immune cell functions and the clinical application of immunotherapy, the precise roles and characteristics of immune cell subtypes, how glioma induces subtype transformation of immune cells and its impact on glioma progression have yet to be understood.

AIM OF THE REVIEW

In this review, we comprehensively center on the four major immune cells within the glioma microenvironment, particularly neutrophils, macrophages, lymphocytes, myeloid-derived suppressor cells (MDSCs), and other significant immune cells. We discuss (1) immune cell subtype markers, (2) glioma-induced immune cell subtype transformation, (3) the mechanisms of each subtype influencing chemotherapy resistance, (4) therapies targeting immune cells, and (5) immune cell-associated single-cell sequencing. Eventually, we identified the characteristics of immune cell subtypes in glioma, comprehensively summarized the exact mechanism of glioma-induced immune cell subtype transformation, and concluded the progress of single-cell sequencing in exploring immune cell subtypes in glioma.

KEY SCIENTIFIC CONCEPTS OF REVIEW

In conclusion, we have analyzed the mechanism of chemotherapy resistance detailly, and have discovered prospective immunotherapy targets, excavating the potential of novel immunotherapies approach that synergistically combines radiotherapy, chemotherapy, and surgery, thereby paving the way for improved immunotherapeutic strategies against glioma and enhanced patient outcomes.

Targeting MS4A4A: A novel pathway to improve immunotherapy responses in glioblastoma

INTRODUCTION

Glioblastoma (GBM) remains a challenging brain tumor to treat, with limited response to PD-1 immunotherapy due to tumor-associated macrophages (TAMs), specifically the M2 phenotype. This study explores the potential of MS4A4A (membrane spanning four domains, subfamily A, member 4A) inhibition in driving M2 macrophage polarization toward the M1 phenotype via the ferroptosis pathway to enhance the effectiveness of immunotherapy in GBM.

METHODS

Single-cell RNA sequencing and spatial transcriptomic analyses were employed to characterize M2 macrophages and MS4A4A expression in GBM. In vitro studies utilizing TAM cultures, flow cytometry, and western blot validations were conducted to assess the impact of MS4A4A on the tumor immune microenvironment and M2 macrophage polarization. In vivo models, including subcutaneous and orthotopic transplantation in mice, were utilized to evaluate the effects of MS4A4A knockout and combined immune checkpoint blockade (ICB) therapy on tumor growth and response to PD-1 immunotherapy.

RESULTS

Distinct subsets of GBM-associated macrophages were identified, with spatial distribution in tumor tissue elucidated. In vivo experiments demonstrated that inhibiting MS4A4A and combining ICB therapy effectively inhibited tumor growth, reshaped the tumor immune microenvironment by reducing M2 TAM infiltration and enhancing CD8+ T-cell infiltration, ultimately leading to complete tumor eradication.

CONCLUSION

MS4A4A inhibition shows promise in converting M2 macrophages to M1 phenotype via ferroptosis, decreasing M2-TAM infiltration, and enhancing GBM response to PD-1 immunotherapy. These findings offer a novel approach to developing more effective immunotherapeutic strategies for GBM.

Nanoparticles for efficient drug delivery and drug resistance in glioma: New perspectives

Gliomas are the most common primary tumors of the central nervous system, with glioblastoma multiforme (GBM) having the highest incidence, and their therapeutic efficacy depends primarily on the extent of surgical resection and the efficacy of postoperative chemotherapy. The role of the intracranial blood-brain barrier and the occurrence of the drug-resistant gene O6-methylguanine-DNA methyltransferase have greatly limited the efficacy of chemotherapeutic agents in patients with GBM and made it difficult to achieve the expected clinical response. In recent years, the rapid development of nanotechnology has brought new hope for the treatment of tumors. Nanoparticles (NPs) have shown great potential in tumor therapy due to their unique properties such as light, heat, electromagnetic effects, and passive targeting. Furthermore, NPs can effectively load chemotherapeutic drugs, significantly reduce the side effects of chemotherapeutic drugs, and improve chemotherapeutic efficacy, showing great potential in the chemotherapy of glioma. In this article, we reviewed the mechanisms of glioma drug resistance, the physicochemical properties of NPs, and recent advances in NPs in glioma chemotherapy resistance. We aimed to provide new perspectives on the clinical treatment of glioma.

Metabolism/Immunity Dual-Regulation Thermogels Potentiating Immunotherapy of Glioblastoma Through Lactate-Excretion Inhibition and PD-1/PD-L1 Blockade

Intrinsic immunosuppressive tumor microenvironment (ITM) and insufficient tumor infiltration of T cells severely impede the progress of glioblastoma (GBM) immunotherapy. In this study, it is identify that inhibiting the expression of glucose transporter 1 (GLUT1) can facilitate the prevention of lactate excretion from tumor glycolysis, which significantly alleviates the lactate-driven ITM by reducing immunosuppressive tumor-associated macrophages (TAMs) and regulatory T cells (Tregs). Simultaneously, the findings show that the generated inflammatory cytokine IFN-γ during immune activation aggravates the immune escape by upregulating immune checkpoint programmed death-ligand 1 (PD-L1) in tumor cells and TAMs. Therefore, an injectable thermogel loaded with a GLUT1 inhibitor BAY-876 and a PD-1/PD-L1 blocker BMS-1 (Gel@B-B) for dual-regulation of metabolism and immunity of GBM is developed. Consequently, in situ injection of Gel@B-B significantly delays tumor growth and prolongs the survival of the orthotopic GBM mouse model. By actively exposing tumor antigens to antigen-presenting cells, the GBM vaccine combined with Gel@B-B is found to significantly increase the fraction of effector T cells (Th1/CTLs) in the tumor microenvironment, thereby remarkably mitigating tumor recurrence long-term. This study may provide a promising strategy for GBM immunotherapy.

New Avenues and Major Achievements in Phytocompounds Research for Glioblastoma Therapy

Phytocompounds have been evaluated for their anti-glioblastoma actions for decades, with promising results from preclinical studies but only limited translation into clinics. Indeed, by targeting multiple signaling pathways deregulated in cancer, they often show high efficacy in the in vitro studies, but their poor bioavailability, low tumor accumulation, and rapid clearance compromise their efficacy in vivo. Here, we present the new avenues in phytocompound research for the improvement of glioblastoma therapy, including the ways to enhance the response to temozolomide using phytochemicals, the current focus on phytocompound-based immunotherapy, or the use of phytocompounds as photosensitizers in photodynamic therapy. Moreover, we present new, intensively evaluated approaches, such as chemical modifications of phytochemicals or encapsulation into numerous types of nanoformulations, to improve their bioavailability and delivery to the brain. Finally, we present the clinical trials evaluating the role of phytocompounds or phytocompound-derived drugs in glioblastoma therapy and the less studied phytocompounds or plant extracts that have only recently been found to possess promising anti-glioblastoma properties. Overall, recent advancements in phytocompound research are encouraging; however, only with more 3D glioblastoma models, in vivo studies, and clinical trials it is possible to upgrade the role of phytocompounds in glioblastoma treatment to a satisfactory level.

The Phytochemical Agathisflavone Modulates miR146a and miR155 in Activated Microglia Involving STAT3 Signaling

MicroRNAs (miRs) act as important post-transcriptional regulators of gene expression in glial cells and have been shown to be involved in the pathogenesis of neurodegenerative diseases, including Alzheimer's disease (AD). Here, we investigated the effects of agathisflavone, a biflavonoid purified from the leaves of Cenostigma pyramidale (Tul.), on modulating the expression of miRs and inflammatory mediators in activated microglia. C20 human microglia were exposed to oligomers of the β-amyloid peptide (Aβ, 500 nM) for 4 h or to lipopolysaccharide (LPS, 1 µg/mL) for 24 h and then treated or not with agathisflavone (1 µM) for 24 h. We observed that β-amyloid and LPS activated microglia to an inflammatory state, with increased expression of miR-146a, miR-155, IL1-β, IL-6, and NOS2. Treatment with agathisflavone resulted in a significant reduction in miR146a and miR-155 induced by LPS or Aβ, as well as inflammatory cytokines IL1-β, IL-6, and NOS2. In cells stimulated with Aβ, there was an increase in p-STAT3 expression that was reduced by agathisflavone treatment. These data identify a role for miRs in the anti-inflammatory effect of agathisflavone on microglia in models of neuroinflammation and AD.

DENDRITIC CELLS IN GLIOBLASTOMA TREATMENT: A MODERN VIEW OF THE PROBLEM AND OWN EXPERIENCE

Glioblastoma (GBM) is the most aggressive primary malignant brain tumor in adults. The improvement of the efficacy of GBM treatment is an urgent problem encouraging the development of novel therapeutic strategies, in particular, immunotherapeutic modalities. With more understanding of the intimate interrelationships between the immune system and the mechanisms involved in cancer origin and progression, the skepticism related to the relevance of the immunotherapeutic approaches in the treatment of brain tumors is gradually decreasing. The review discloses the modern concepts on the association between CNS and the immune system. For a long time, CNS was considered as the immunoprivileged site that prevents the effects of immunotherapy in the treatment of brain tumors. Nowadays, these views are reconsidered, which opens the way to the use of immunotherapeutic approaches in GBM treatment. The results of the recent clinical trials on immunotherapy as a supplement to the conventional GBM treatment are considered. Vaccines based on the dendritic cell (DC) technology are regarded as the most promising for this purpose. The preliminary results of the Ukrainian clinical study are also presented and discussed. The results of the international clinical trials as well as our own experience give evidence of the relevance for using DC vaccines in the complex treatment of GBM, which is supported by the increased survival of patients and the safety of vaccine application. It is of high importance that GBM patients with the most unfavorable prognosis can benefit from DC vaccines as a component of the complex treatment. The prospects for immunotherapy in neurooncology are discussed.

EIF4A3 induced circGRIK2 promotes the malignancy of glioma by regulating the miR-1303/HOXA10 axis

In recent years, the role of circular RNAs (circRNAs) in glioma has become increasingly important. However, there are still many newly discovered circRNAs with unknown functions that require further study. In this study, circRNA sequencing, qPCR, MTS, EdU, Transwell, and other assays were conducted to detect the expression and malignant effects of a novel circRNA molecule, circGRIK2, in glioma. qPCR, western blotting, RIP, and luciferase reporter gene experiments were used to investigate the downstream molecular mechanisms of circGRIK2. Our study found that circGRIK2 was highly expressed in glioma and promoted glioma cell viability, proliferation, invasion, and migration. Mechanistically, circGRIK2 acted as a competitive sponge for miR-1303, upregulating the expression of HOXA10 to exert its oncogenic effects. Additionally, the RNA-binding protein EIF4A3 could bind to and stabilize circGRIK2, leading to its high expression in glioblastoma. The discovery of circGRIK2 in this study not only contributes to a better understanding of the biological mechanisms of circGRIK2 in glioma but also provides a new target for molecular targeted therapy.

A Network Pharmacology Prediction and Molecular Docking-Based Strategy to Explore the Potential Pharmacological Mechanism of Astragalus membranaceus for Glioma

Glioma treatment in traditional Chinese medicine has a lengthy history. Astragalus membranaceus, a traditional Chinese herb that is frequently utilized in therapeutic practice, is a component of many Traditional Chinese Medicine formulas that have been documented to have anti-glioma properties. Uncertainty persists regarding the molecular mechanism behind the therapeutic effects. Based on results from network pharmacology and molecular docking, we thoroughly identified the molecular pathways of Astragalus membranaceus' anti-glioma activities in this study. According to the findings of the enrichment analysis, 14 active compounds and 343 targets were eliminated from the screening process. These targets were mainly found in the pathways in cancer, neuroactive ligand-receptor interaction, protein phosphorylation, inflammatory response, positive regulation of phosphorylation, and inflammatory mediator regulation of Transient Receptor Potential (TRP) channels. The results of molecular docking showed that the active substances isoflavanone and 1,7-Dihydroxy-3,9-dimethoxy pterocarpene have strong binding affinities for the respective targets ESR2 and PTGS2. In accordance with the findings of our investigation, Astragalus membranaceus active compounds exhibit a multicomponent and multitarget synergistic therapeutic impact on glioma by actively targeting several targets in various pathways. Additionally, we propose that 1,7-Dihydroxy-3,9-dimethoxy pterocarpene and isoflavanone may be the main active ingredients in the therapy of glioma.

mRNA vaccine in gastrointestinal tumors: Immunomodulatory effects and immunotherapy

Gastrointestinal tumors remain a significant healthcare burden worldwide, necessitating the development of innovative therapeutic strategies. mRNA vaccines have emerged as a promising approach in cancer immunotherapy, harnessing the immune system's potential to recognize and eliminate tumor cells. mRNA vaccines offer several advantages, including their ability to elicit both innate and adaptive immune responses, ease of production, and adaptability to different tumor types. In the context of gastrointestinal tumors, mRNA vaccines hold great potential as a therapeutic strategy. In this review, we will delve into the immunomodulatory mechanisms and immunotherapy strategies of mRNA vaccines in gastrointestinal tumors. Additionally, we will discuss the challenges and ongoing research efforts in optimizing mRNA vaccine development, delivery, and stability. By understanding the potential of mRNA vaccines in addressing the unmet medical need of gastrointestinal tumors, we aim to pave the way for improved treatment strategies and better patient outcomes.