Targeting tumor-associated macrophages to synergize tumor immunotherapy

Emerging nanomedicines for macrophage-mediated cancer therapy

Tumor-associated macrophages (TAMs) contribute to tumor progression by promoting angiogenesis, remodeling the tumor extracellular matrix, inducing tumor invasion and metastasis, as well as immune evasion. Due to the high plasticity of TAMs, they can polarize into different phenotypes with distinct functions, which are primarily categorized as the pro-inflammatory, anti-tumor M1 type, and the anti-inflammatory, pro-tumor M2 type. Notably, anti-tumor macrophages not only directly phagocytize tumor cells, but also present tumor-specific antigens and activate adaptive immunity. Therefore, targeted regulation of TAMs to unleash their potential anti-tumor capabilities is crucial for improving the efficacy of cancer immunotherapy. Nanomedicine serves as a promising vehicle and can inherently interact with TAMs, hence, emerging as a new paradigm in cancer immunotherapy. Due to their controllable structures and properties, nanomedicines offer a plethora of advantages over conventional drugs, thus enhancing the balance between efficacy and toxicity. In this review, we provide an overview of the hallmarks of TAMs and discuss nanomedicines for targeting TAMs with a focus on inhibiting recruitment, depleting and reprogramming TAMs, enhancing phagocytosis, engineering macrophages, as well as targeting TAMs for tumor imaging. We also discuss the challenges and clinical potentials of nanomedicines for targeting TAMs, aiming to advance the exploitation of nanomedicine for cancer immunotherapy.

Tissue-resident immune cells: from defining characteristics to roles in diseases

Tissue-resident immune cells (TRICs) are a highly heterogeneous and plastic subpopulation of immune cells that reside in lymphoid or peripheral tissues without recirculation. These cells are endowed with notably distinct capabilities, setting them apart from their circulating leukocyte counterparts. Many studies demonstrate their complex roles in both health and disease, involving the regulation of homeostasis, protection, and destruction. The advancement of tissue-resolution technologies, such as single-cell sequencing and spatiotemporal omics, provides deeper insights into the cell morphology, characteristic markers, and dynamic transcriptional profiles of TRICs. Currently, the reported TRIC population includes tissue-resident T cells, tissue-resident memory B (BRM) cells, tissue-resident innate lymphocytes, tissue-resident macrophages, tissue-resident neutrophils (TRNs), and tissue-resident mast cells, but unignorably the existence of TRNs is controversial. Previous studies focus on one of them in specific tissues or diseases, however, the origins, developmental trajectories, and intercellular cross-talks of every TRIC type are not fully summarized. In addition, a systemic overview of TRICs in disease progression and the development of parallel therapeutic strategies is lacking. Here, we describe the development and function characteristics of all TRIC types and their major roles in health and diseases. We shed light on how to harness TRICs to offer new therapeutic targets and present burning questions in this field.

Interactions and communications in lung tumor microenvironment: Chemo/radiotherapy resistance mechanisms and therapeutic targets

The lung tumor microenvironment is composed of various cell types, including cancer cells, stromal and immune cells, as well as extracellular matrix (ECM). These cells and surrounding ECM create a stiff, hypoxic, acidic, and immunosuppressive microenvironment that can augment the resistance of lung tumors to different forms of cell death and facilitate invasion and metastasis. This environment can induce chemo/radiotherapy resistance by inducing anti-apoptosis mediators such as phosphoinositide 3-kinase (PI3K)/Akt, signal transducer and activator of transcription 3 (STAT3), and nuclear factor of κB (NF-κB), leading to the exhaustion of antitumor immunity and further resistance to chemo/radiotherapy. In addition, lung tumor cells can resist chemo/radiotherapy by boosting multidrug resistance mechanisms and antioxidant defense systems within cancer cells and other TME components. In this review, we discuss the interactions and communications between these different components of the lung TME and also the effects of hypoxia, immune evasion, and ECM remodeling on lung cancer resistance. Finally, we review the current strategies in preclinical and clinical studies, including the inhibition of checkpoint molecules, chemoattractants, cytokines, growth factors, and immunosuppressive mediators such as programmed death 1 (PD-1), insulin-like growth factor 2 (IGF-2) for targeting the lung TME to overcome resistance to chemotherapy and radiotherapy.

Harnessing the tumor microenvironment: targeted cancer therapies through modulation of epithelial-mesenchymal transition

The tumor microenvironment (TME) is integral to cancer progression, impacting metastasis and treatment response. It consists of diverse cell types, extracellular matrix components, and signaling molecules that interact to promote tumor growth and therapeutic resistance. Elucidating the intricate interactions between cancer cells and the TME is crucial in understanding cancer progression and therapeutic challenges. A critical process induced by TME signaling is the epithelial-mesenchymal transition (EMT), wherein epithelial cells acquire mesenchymal traits, which enhance their motility and invasiveness and promote metastasis and cancer progression. By targeting various components of the TME, novel investigational strategies aim to disrupt the TME's contribution to the EMT, thereby improving treatment efficacy, addressing therapeutic resistance, and offering a nuanced approach to cancer therapy. This review scrutinizes the key players in the TME and the TME's contribution to the EMT, emphasizing avenues to therapeutically disrupt the interactions between the various TME components. Moreover, the article discusses the TME's implications for resistance mechanisms and highlights the current therapeutic strategies toward TME modulation along with potential caveats.

Dual Checkpoint Inhibition in M2 Macrophages via Anti-PD-L1 and siRNA-Loaded M1-Exosomes: Enhancing Tumor Immunity through RNA-Targeting Strategies

The interaction between a cluster of differentiation 47 (CD47) on cancer cells and signal regulatory protein alpha (SIRPα) on macrophages is thought to hinder macrophage phagocytic activity, which can be blocked by combining siRNAs targeting SIRPα (siSIRPα) with simultaneous involvement of activating receptors like FcRs (Fc receptors) anti-programmed death-ligand 1 (anti-PD-L1). For this study, M1 macrophage-derived exosomes were used to deliver the siRNAs, isolated from lipopolysaccharide (LPS)-stimulated RAW264.7 cells and electroporated with siSIRPα. The exosomes were characterized and used to treat M2 macrophages (RAW264.7 cells triggered by interleukin-4 (IL-4)), and the polarization of macrophages was evaluated using flow cytometry, real-time PCR, ELISA, and phagocytosis assays. The anti-tumor functions of treated macrophages were assessed by co-culturing them with 4T1 cells, evaluating the migration and invasion of 4T1 cells, and phagocytosis of 4T1 cells by macrophages. The results showed that siSIRPα-loaded M1-exosomes caused polarization of M2 macrophage toward M1 phenotype and enhanced anti-tumor effects by reducing migration and invasion of 4T1 cells and enhancing phagocytosis of 4T1 cells by macrophages, especially with combination of anti-PD-L1. This study suggests that blocking the SIRPα-CD47 interaction and the PD-1/PD-L1 pathway in M2 macrophages could be a promising therapeutic approach to enhance anti-tumor immune responses.

Macrophage polarization in sepsis: Emerging role and clinical application prospect

Sepsis is a severe, potentially fatal condition defined by organ dysfunction due to excessive inflammation. Its complex pathogenesis and poor therapeutic outcomes pose significant challenges in treatment. Macrophages, with their high heterogeneity and plasticity, play crucial roles in both the innate and adaptive immune systems. They can polarize into M1-like macrophages, which promote pro-inflammatory responses, or M2-like macrophages, which mediate anti-inflammatory responses, positioning them as critical mediators in the immune response during sepsis.Macrophages are the main regulators of inflammatory responses, and their polarization is also regulated by inflammatory signaling pathways. This review highlights recent advances in the inflammatory signaling pathways involved in sepsis, mechanism of macrophage polarization mediated by inflammation-related signaling pathways in sepsis, and the role of signaling pathway mediated macrophage polarization in organ dysfunction involved in sepsis. We also explore the therapeutic potential of targeting macrophage polarization for immunotherapy, offering new perspectives on macrophage-targeted treatments for sepsis.

Targeting macrophages in cancer immunotherapy: Frontiers and challenges

BACKGROUND

Cancer immunotherapy has emerged as a groundbreaking approach in cancer treatment, primarily realized through the manipulation of immune cells, notably T cell adoption and immune checkpoint blockade. Nevertheless, the manipulation of T cells encounters formidable hurdles. Macrophages, serving as the pivotal link between innate and adaptive immunity, play crucial roles in phagocytosis, cytokine secretion, and antigen presentation. Consequently, macrophage-targeted therapies have garnered significant attention.

AIM OF REVIEW

We aim to provide the most cutting-edge insights and future perspectives for macrophage-targeted therapies, fostering the development of novel and effective cancer treatments.

KEY SCIENTIFIC CONCEPTS OF REVIEW

To date, the forefront strategies for macrophage targeting encompass: altering their plasticity, harnessing CAR-macrophages, and targeting phagocytosis checkpoints. Macrophages are characterized by their remarkable diversity and plasticity, offering a unique therapeutic target. In this context, we critically analyze the innovative strategies aimed at transforming macrophages from their M2 (tumor-promoting) to M1 (tumor-suppressing) phenotype. Furthermore, we delve into the design principles, developmental progress, and advantages of CAR-macrophages. Additionally, we illuminate the challenges encountered in targeting phagocytosis checkpoints on macrophages and propose potential strategies to overcome these obstacles.

Tricomponent immunoactivating nanomedicine to downregulate PD-L1 and polarize macrophage for photodynamic immunotherapy of colorectal cancer

The unsatisfactory immunotherapeutic responses are primarily attributed to the insufficient immune recognition and the presence of an immunosuppressive tumor microenvironment (ITM). This study focuses on the development of a tricomponent immunoactivating nanomedicine called TIN that combines a photosensitizer, an inhibitor of epidermal growth factor receptor (EGFR) and a CSF-1R inhibitor to enable photodynamic immunotherapy by downregulating PD-L1 expression and repolarizing tumor-associated macrophages (TAMs). TIN is designed to facilitate the drug delivery and target specific pathways involved in tumor progression. By inhibiting the activity of EGFR and CSF-1R, TIN reduces PD-L1 expression on tumor cells and induces the TAMs polarization to M1 phenotype, restoring the immune recognition of T cells and the phagocytosis of macrophage to reshape the immunosuppressive microenvironment. Additionally, the photodynamic therapy (PDT) of TIN can greatly destroy the primary tumor and trigger immunogenic cell death (ICD). Importantly, the immune checkpoint blockade effect of TIN can enhance the immune response of PDT-induced ICD for metastatic tumor treatment. This study presents a self-assembling strategy for the development of an all-in-one nanomedicine, effectively integrating multiple therapeutic modalities to provide a comprehensive and systemic approach for tumor suppression.

STC1 encapsulated in small extracellular vesicles from laryngeal squamous cell carcinoma cells induces CD8+ T cell dysfunction by reprogramming tumor-associated macrophages into M2-like macrophages

BACKGROUND

Tumor-derived small extracellular vesicles (sEVs) play an essential role in reprogramming the tumor microenvironment. Metabolic reprogramming is an essential prerequisite for M2 polarization of tumor-associated macrophages (TAMs). This M2 phenotype is closely related to the immune dysfunction of CD8+ T cells and subsequent tumor progression. This study evaluates the role of laryngeal squamous cell carcinoma cell-derived small extracellular vesicles (LSCC-sEVs) in M2 polarization of TAMs and CD8+ T cell dysfunction, and delineates the underlying mechanisms.

METHODS

Human leukemia monocyte cell line (THP-1) was induced to differentiate into M0 macrophages using phorbol 12-myristate 13-acetate. M0 macrophages were incubated with sEVs derived from LSCC cells TU212. CD8+T cells, extracted from peripheral blood mononuclear cells of healthy volunteer donors, were co-cultured with the LSCC-sEV-treated M0 macrophages to evaluate their proliferation, and immune function. The role of LSCC-sEVs was investigated in macrophage tumor-bearing mouse models.

RESULTS

LSCC-sEVs promoted TAM M2 polarization and impaired CD8+ T cell function, attributing to PD-L1 expression upregulation. In addition, suppression of metabolic reprogramming could partially reverse LSCC-sEV-induced CD8+ T cell dysfunction. STC-1 was found highly enriched in LSCC-sEVs. Knockdown of STC1 abrogated metabolic reprogramming of TAMs into M2-like macrophages and restored CD8+ T cell function. Importantly, in vivo results showed that LSCC-sEVs transform TAMs into M2 phenotype by mediating metabolic reprogramming and induce CD8+ T cell dysfunction, ultimately accelerating tumor growth.

CONCLUSION

Our data reveal a previously undescribed role for LSCC-sEVs in the regulation of M2 polarization of TAMs and immune cell function through STC1 mediated metabolic reprogramming.

Multifunctional ICG-SB@Lip-ZA Nanosystem Focuses on Remodeling the Inflammatory-Immunosuppressive Microenvironment After Photothermal Therapy to Potentiate Cancer Photothermal Immunotherapy

Achieving full eradication of residual tumors post photothermal therapy (PTT) hinges on the immune system's activation and response. Nevertheless, the resultant local inflammation attracts a significant influx of aberrant immune cells and fibroblasts, such as tumor-associated macrophages (TAMs) and cancer-associated fibroblasts (CAFs), following tumor PTT. This phenomenon exacerbates immune evasion and the persistence of residual tumor cells, culminating in tumor recurrence and advancement. To tackle this challenge, a combined therapeutic approach utilizing multifunctional ICG-SB@Lip-ZA nanosystem has been introduced. Indocyanine green (ICG) as a photothermal-transducer ablated tumor cells, zoledronic acid (ZA) depletes TAMs recruited by the inflammatory tumor microenvironment (mostly M2-like phenotype), SB-505124 affects CAFs proliferation in the tumor microenvironment (TME) by inhibiting the transforming growth factor-β （TGF-β） pathway, thereby removing physical barriers to T cell infiltration. In a breast cancer model, these immunomodulatory nanoliposomes markedly decrease the population of M2-like TAMs in the TME, eliminate physical barriers hindering T cell infiltration, reshape the inflammatory immune-suppressive tumor microenvironment, eventually leading to a rate of tumor eradication of 94%. This multifunctional ICG-SB@Lip-ZA nanosystem (including photothermal conversion, TAM depletion, and TGF-β pathway blockade) offers a promising strategy for mitigating the deteriorating tumor microenvironment following PTT and presents a more efficient approach for clinical photothermal-immune combination therapy.

The Dual Role of Cellular Senescence in Macrophages: Unveiling the Hidden Driver of Age-Related Inflammation in Kidney Disease

Aging is a complex biological process that involves the gradual decline of cellular, tissue, and organ functions. In kidney, aging manifests as tubular atrophy, glomerulosclerosis, and progressive renal function decline. The critical role of senescence-associated macrophage in diseases, particularly kidney diseases, is increasingly recognized. During this process, macrophages exhibit a range of pro-damage response to senescent tissues and cells, while the aging of macrophages themselves also significantly influences disease progression, creating a bidirectional regulatory role between aging and macrophages. To explore this bidirectional mechanism, this review will elucidate the origin, characteristic, phenotype, and function of macrophages in response to the senescence-associated secretory phenotype (SASP), extracellular vesicles from senescent cells, and the senescence cell-engulfment suppression (SCES), particularly in the context of kidney disease. Additionally, it will discuss the characteristics of senescent macrophage, such as common markers, and changes in autophagy, metabolism, gene regulation, phagocytosis, antigen presentation, and exosome secretion, along with their physiological and pathological impacts on renal tissue cells. Furthermore, exploring therapies and drugs that modulate the function of senescent macrophages or eliminate senescent cells may help slow the progression of kidney aging and damage.

Histone lactylation in macrophage biology and disease: from plasticity regulation to therapeutic implications

Epigenetic modifications have been identified as critical molecular determinants influencing macrophage plasticity and heterogeneity. Among these, histone lactylation is a recently discovered epigenetic modification. Research examining the effects of histone lactylation on macrophage activation and polarization has grown substantially in recent years. Evidence increasingly suggests that lactate-mediated changes in histone lactylation levels within macrophages can modulate gene transcription, thereby contributing to the pathogenesis of various diseases. This review provides a comprehensive analysis of the role of histone lactylation in macrophage activation, exploring its discovery, effects, and association with macrophage diversity and phenotypic variability. Moreover, it highlights the impact of alterations in macrophage histone lactylation in diverse pathological contexts, such as inflammation, tumorigenesis, neurological disorders, and other complex conditions, and demonstrates the therapeutic potential of drugs targeting these epigenetic modifications. This mechanistic understanding provides insights into the underlying disease mechanisms and opens new avenues for therapeutic intervention.

Targeting tumor-associated macrophages: Novel insights into immunotherapy of skin cancer

BACKGROUND

The incidence of skin cancer is currently increasing, and conventional treatment options inadequately address the demands of disease management. Fortunately, the recent rapid advancement of immunotherapy, particularly immune checkpoint inhibitors (ICIs), has ushered in a new era for numerous cancer patients. However, the efficacy of immunotherapy remains suboptimal due to the impact of the tumor microenvironment (TME). Tumor-associated macrophages (TAMs), a major component of the TME, play crucial roles in tumor invasion, metastasis, angiogenesis, and immune evasion, significantly impacting tumor development. Consequently, TAMs have gained considerable attention in recent years, and their roles have been extensively studied in various tumors. However, the specific roles of TAMs and their regulatory mechanisms in skin cancer remain unclear.

AIM OF REVIEW

This paper aims to elucidate the origin and classification of TAMs, investigate the interactions between TAMs and various immune cells, comprehensively understand the precise mechanisms by which TAMs contribute to the pathogenesis of different types of skin cancer, and finally discuss current strategies for targeting TAMs in the treatment of skin cancer.

KEY SCIENTIFIC CONCEPTS OF OVERVIEW

With a specific emphasis on the interrelationship between TAMs and skin cancer, this paper posits that therapeutic modalities centered on TAMs hold promise in augmenting and harmonizing with prevailing clinical interventions for skin cancer, thereby charting a novel trajectory for advancing the landscape of immunotherapeutic approaches for skin cancer.

Capturing Hydrophilic Chemotherapeutics Agents Into siRNA-Encapsulated Vesicle-Like Nanoparticles for Convenient ICB-Chemo Combination Therapy

Clinical evidence has demonstrated that combining immune checkpoint blockade (ICB) therapy with chemotherapy significantly improves response rates to ICB therapy and therapeutic efficacy in various tumor types. However, a convenient method for achieving synergistic ICB therapy and chemotherapy with precise co-delivery of both agents is still highly desirable. In this study, a strategy for co-delivering small interfering RNA (siRNA) encapsulated in vesicle-like nanoparticles (VNPsiRNA) and chemotherapeutic drugs is aimed to develop. It is discovered that the hydrophilic chemotherapeutic drug mitoxantrone hydrochloride (MTO·2HCl) can be captured into VNPsiRNA. The resulting VNPsiRNACpMTO can simultaneously block immune checkpoints via RNA silencing and induce chemotherapeutic effects on tumor cells. The mechanism of MTO·2HCl is elucidates, captures, and demonstrates the superior therapeutic effect of VNPsiRNACpMTO through chemo-immunotherapy. This strategy can also be extended to deliver other hydrochloride anticancer drugs, such as doxorubicin hydrochloride (DOX·HCl), for achieving synergistic combination therapy. This study provides a facile strategy for enhancing combined ICB and chemotherapy via co-delivering siRNA and chemotherapeutic drugs, offering a promising approach to cancer treatment.

Macrophage subtypes inhibit breast cancer proliferation in culture

Macrophages are a highly plastic cell type that adopt distinct subtypes and functional states depending on environmental cues. These functional states can vary widely, with distinct macrophages capable of displaying opposing functions. We sought to understand how macrophage subtypes that exist on two ends of a spectrum influence the function of other cells. We used a coculture system with primary human macrophages to probe the effects of macrophage subtypes on breast cancer cell proliferation. Our studies revealed a surprising phenotype in which both macrophage subtypes inhibited cancer cell proliferation compared with cancer cells alone. Of particular interest, using two different proliferation assays with two different breast cancer cell lines, we showed that differentiating macrophages into a "protumor" subtype inhibited breast cancer cell proliferation. These findings are inconsistent with the prevailing interpretation that "protumor" macrophages promote cancer cell proliferation and suggest a re-evaluation of how these interpretations are made.

Intelligent Pyroptosis Inducer for Precise and Augmented Tumor Therapy Through Specific Activation Pyroptosis in Tumor

Pyroptosis inducer, a powerful anti-tumor agent that causes obvious programmed cell death and immune stimulation, has been challenged to trigger specific pyroptotic tumor cell death while keeping pyroptosis silence in normal cells. Here, an intelligent inducer is reported that acts as a reactive oxygen species (ROS) scavenger in normal cells to keep pyroptosis silence, while serving as ROS generator to induce obvious pyroptotic tumor cells death dependent on high hydrogen peroxide levels and near-infrared laser irradiation. This switchable activity ensures this inducer to precisely kill the tumor cells with augmented immunogenicity while causing minimal damage to normal cells. Moreover, the catalase-like activity endows this inducer to overcome limitation of tumor hypoxia on ROS generation and show significant pyroptosis activation, further initiating the immune response to inhibit the tumor metastases in vivo. This study provides valuable insights into design new pyroptosis inducer with controllable pyroptosis activity to specifically induce programmed tumor cell pyroptosis for precise and augmented tumor therapy with minimal side effects.

Modulation of Tumor-Associated Macrophages to Overcome Immune Suppression in the Hepatocellular Carcinoma Microenvironment

Hepatocellular carcinoma (HCC) is a major global health issue characterized by poor prognosis and complex tumor biology. One of the critical components of the HCC tumor microenvironment (TME) is tumor-associated macrophages (TAMs), which play a pivotal role in modulating tumor growth, immune evasion, and metastasis. Macrophages are divided into two major subtypes: pro-inflammatory M1 and anti-inflammatory M2, both of which may exist in TME with altered function and proportion. The anti-inflammatory M2 macrophages are further subdivided into four distinct immune suppressive subsets. TAMs are generally counted as M2-like macrophages with altered immune suppressive functions that exert a significant influence on both cancer progression and the ability of tumors to escape immune surveillance. Their involvement in modulating immune responses via different mechanisms at the local and systemic levels has made them a key target for therapeutic interventions seeking to enhance treatment outcomes. How TAMs' depletion influences immune responses in cancer is the primary interest in cancer immunotherapies. The purpose of this review is to delve into the recent progress made in TAM-targeting therapies. We will explore the current theories, benefits, and challenges associated with TAMs' depletion or inhibition. The manuscript concludes with future directions and potential implications for clinical practice.

The role and research progress of tumor-associated macrophages in cervical cancer

Tumor-associated macrophages (TAMs) are important immune cells in the tumor micro-environment (TME) and play a key role in the occurrence and development of cervical cancer. Besides, targeting TAMs can significantly inhibit cervical cancer tumor growth, invasion, metastasis, and angiogenesis as well as affect immune regulation. This review summarizes the correlation between TAM and tumors, the mechanism of action of TAM in cervical cancer, and the potential application of TAM in the treatment of cervical cancer. Therefore, this study may provide new ideas and targets for the development of further treatment strategies for cervical cancer patients.

Nanoplatform-based synergistic cancer Immuno-Chemodynamic therapy

Immunotherapy has made excellent breakthroughs in the field of cancer treatments, but faces challenges with low immunogenicity of tumor cells and an immunosuppressive tumor microenvironment (ITME). The emerging chemodynamic therapy (CDT) based on the Fenton/Fenton-like reaction can induce immunogenic cell death (ICD) to enhance tumor immunogenicity, facilitating the transition from immune-cold to immune-hot tumors. Synergistic CDT and immunotherapy based on advanced nanotechnology have shown immense promise for improving therapeutic efficacy while minimizing side effects in cancer treatment. This review summarizes and discusses recent advances in the field, with the goal of designing a high-quality nanoplatform to enhance synergistic CDT in combination with immunotherapy and lay the foundation for its future clinical translation.

Ubiquitin-Conjugating Enzyme Ubc13 in Macrophages Suppresses Lung Tumor Progression Through Inhibiting PD-L1 Expression

Tumor cell-intrinsic ubiquitin-conjugating enzyme Ubc13 promotes tumorigenesis, yet how Ubc13 in immune cell compartments regulates tumor progression remains elusive. Here, we show that myeloid-specific deletion of Ubc13 (Ubc13fl/flLyz2Cre) leads to accelerated transplanted lung tumor growth in mice. Compared with their littermate controls, tumor-bearing Ubc13fl/flLyz2Cre mice had lower proliferation and effector function of CD8+ T lymphocytes, accompanied by increased infiltration of myeloid-derived suppressor cells within the tumor microenvironment. Mechanistically, Ubc13 deficiency leads to upregulation of Arg1 and PD-L1, the latter is modulated by reduced Ubc13-mediated K63-linked polyubiquitination and increasing activation of Akt, thereby inducing skewness to protumoral polarization and immunosuppressive manifestation. Taken together, we reveal that macrophage-intrinsic Ubc13 restrains lung tumor progression, indicating that activating Ubc13 in macrophages could be an effective immunotherapeutic regimen for lung cancer.

The Emerging Role of Schwann Cells in the Tumor Immune Microenvironment and Its Potential Clinical Application

As the primary glial cells in the peripheral nervous system (PNS), Schwann cells (SCs) have been proven to influence the behavior of cancer cells profoundly and are involved in cancer progression through extensive interactions with cancer cells and other stromal cells. Indeed, the tumor microenvironment (TME) is a critical factor that can significantly limit the efficacy of immunotherapeutic approaches. The TME promotes tumor progression in part by reshaping an immunosuppressive state. The immunosuppressive TME is the result of the crosstalk between the tumor cells and the different immune cell subsets, including macrophages, natural killer (NK) cells, dendritic cells (DCs), lymphocytes, myeloid-derived suppressor cells (MDSCs), etc. They are closely related to the anti-tumor immune status and the clinical prognosis of cancer patients. Increasing research demonstrates that SCs influence these immune cells and reshape the formation of the immunosuppressive TME via the secretion of various cytokines, chemokines, and other effector molecules, eventually facilitating immune evasion and tumor progression. In this review, we summarize the SC reprogramming in TME, the emerging role of SCs in tumor immune microenvironment, and the underlying mechanisms involved. We also discuss the possible therapeutic strategies to selectively target SCs, providing insights and perspectives for future research and clinical studies involving SC-targeted treatment.

PD-1 interactome in osteosarcoma: identification of a novel PD-1/AXL interaction conserved between humans and dogs

The PD-1/PDL-1 immune checkpoint inhibitors revolutionized cancer treatment, yet osteosarcoma remains a therapeutic challenge. In some types of cancer, PD-1 receptor is not solely expressed by immune cells but also by cancer cells, acting either as a tumor suppressor or promoter. While well-characterized in immune cells, little is known about the role and interactome of the PD-1 pathway in cancer. We investigated PD-1 expression in human osteosarcoma cells and studied PD-1 protein-protein interactions in cancer. Using U2OS cells as a model, we confirmed PD-1 expression by western blotting and characterized its intracellular as well as surface localization through flow cytometry and immunofluorescence. High-throughput analysis of PD-1 interacting proteins was performed using a pull-down assay and quantitative mass spectrometry proteomic analysis. For validation and molecular modeling, we selected tyrosine kinase receptor AXL-a recently reported cancer therapeutic target. We confirmed the PD-1/AXL interaction by immunoblotting and proximity ligation assay (PLA). Molecular dynamics (MD) simulations uncovered binding affinities and domain-specific interactions between extracellular (ECD) and intracellular (ICD) domains of PD-1 and AXL. ECD complexes exhibited strong binding affinity, further increasing for the ICD complexes, emphasizing the role of ICDs in the interaction. PD-1 phosphorylation mutant variants (Y223F and Y248F) did not disrupt the interaction but displayed varying strengths and binding affinities. Using bemcentinib, a selective AXL inhibitor, we observed reduced binding affinity in the PD-1/AXL interaction, although it was not abrogated. To facilitate the future translation of this finding into clinical application, we sought to validate the interaction in canine osteosarcoma. Osteosarcoma spontaneously occurs at significantly higher frequency in dogs and shares close genetic and pathological similarities with humans. We confirmed endogenous expression of PD-1 and AXL in canine osteosarcoma cells, with PD-1/AXL interaction preserved in the dog cells. Also, the interacting residues remain conserved in both species, indicating an important biological function of the interaction. Our study shed light on the molecular basis of the PD-1/AXL interaction with the implication for its conservation across species, providing a foundation for future research aimed at improving immunotherapy strategies and developing novel therapeutic approaches.

PFOS and Its Commercial Alternative, 6:2 Cl-PFESA, Induce Multidrug Resistance in Pancreatic Cancer

Per- and polyfluoroalkyl substances (PFAS), specifically perfluorooctanesulfonate (PFOS) and its alternative, 2-[(6-chloro-1,1,2,2,3,3,4,4,5,5,6,6-dodecafluorohexyl)oxy]-1,1,2,2-tetrafluoroethanesulfonic acid (6:2 Cl-PFESA), are associated with environmental health concerns and potential cancer progression. However, their impact on multidrug resistance (MDR) in pancreatic cancer (PC) chemotherapy remains unclear. Here, we employed drug-sensitivity assays, including IC50 calculations, in vitro and in vivo models with various chemotherapeutics, and paclitaxel (PTX) as a representative agent, combined with transcriptomic/proteomic sequencing and clinical prognostic analysis, to identify MDR-related genes and validate their relevance, with the objective of establishing the correlation between PFOS/6:2 Cl-PFESA exposure and MDR in PC at molecular, cellular, and animal model levels. Our findings demonstrate that PFOS/6:2 Cl-PFESA exposure increases the drug IC50 in three different PC cell lines for various chemotherapeutic agents. Compared with PFOS, 6:2 Cl-PFESA demonstrated a more pro-MDR effect on PC cells in vitro. In vivo experiments further revealed that PFOS/6:2 Cl-PFESA exposures significantly reduced the efficacy of PTX in PC, with inhibition rates dropping from 78.3% to 23.8%/6.1%, respectively (p < 0.05). This effect was driven by the aberrant activation of the PI3K-ABCB1 pathway, with 6:2 Cl-PFESA demonstrating a stronger capacity to promote this signal pathway's expression and function compared with PFOS. These data suggest that exposure to PFAS may elevate the risk of MDR and subsequent disease progression. Although marketed as a safer alternative to PFOS, the notable impact of 6:2 Cl-PFESA on MDR highlights the necessity for a comprehensive assessment of its potential carcinogenic risks.

Tumor-Targeted Catalytic Immunotherapy

Cancer immunotherapy holds significant promise for improving cancer treatment efficacy; however, the low response rate remains a considerable challenge. To overcome this limitation, advanced catalytic materials offer potential in augmenting catalytic immunotherapy by modulating the immunosuppressive tumor microenvironment (TME) through precise biochemical reactions. Achieving optimal targeting precision and therapeutic efficacy necessitates a thorough understanding of the properties and underlying mechanisms of tumor-targeted catalytic materials. This review provides a comprehensive and systematic overview of recent advancements in tumor-targeted catalytic materials and their critical role in enhancing catalytic immunotherapy. It highlights the types of catalytic reactions, the construction strategies of catalytic materials, and their fundamental mechanisms for tumor targeting, including passive, bioactive, stimuli-responsive, and biomimetic targeting approaches. Furthermore, this review outlines various tumor-specific targeting strategies, encompassing tumor tissue, tumor cell, exogenous stimuli-responsive, TME-responsive, and cellular TME targeting strategies. Finally, the discussion addresses the challenges and future perspectives for transitioning catalytic materials into clinical applications, offering insights that pave the way for next-generation cancer therapies and provide substantial benefits to patients in clinical settings.

Renal cell carcinoma and macrophage research: A bibliometric analysis (2004-2023)

To analyze hotspots and trends in renal cell carcinoma (RCC)-macrophage research using bibliometric analysis, although numerous studies on macrophages in RCC have been recently reported, understanding the progressive trends in this field remains challenging. Publications focused on macrophages in RCC were extracted from the Web of Science Core Collection. VOSviewer, Citespace, and Bibliometrics online platforms were used to visualize hot topics and global trends in RCC-macrophage research. In total, 778 papers were collected. China produced the most articles; however, the United States accounted for the largest number of citations. Oncology journals published the most articles, and these were cited most frequently. Based on keyword analysis, "prognosis," "immunotherapy," "tumor microenvironment," and "immune infiltration" represented the primary research hotspots. In summary, RCC-macrophage studies have emerged as a key research focus; particularly, incorporating multiomics data and applying artificial intelligence for predictive modeling have demonstrated significant potential. Our study suggests that the resistance mechanism of immune checkpoint inhibitors and the interaction between macrophages and immune checkpoint inhibitors will be pivotal areas for future research.

Targeting caspase-8: a new strategy for combating hepatocellular carcinoma

Hepatocellular carcinoma (HCC) represents the most prevalent form of primary liver cancer and has a high mortality rate. Caspase-8 plays a pivotal role in an array of cellular signaling pathways and is essential for the governance of programmed cell death mechanisms, inflammatory responses, and the dynamics of the tumor microenvironment. Dysregulation of caspase-8 is intricately linked to the complex biological underpinnings of HCC. In this manuscript, we provide a comprehensive review of the regulatory roles of caspase-8 in apoptosis, necroptosis, pyroptosis, and PANoptosis, as well as its impact on inflammatory reactions and the intricate interplay with critical immune cells within the tumor microenvironment, such as tumor-associated macrophages, T cells, natural killer cells, and dendritic cells. Furthermore, we emphasize how caspase-8 plays pivotal roles in the development, progression, and drug resistance observed in HCC, and explore the potential of targeting caspase-8 as a promising strategy for HCC treatment.

Critical Role of Extracellular Vesicles in Diffuse Large B-Cell Lymphoma; Pathogenesis, Potential Biomarkers, and Targeted Therapy-A Narrative Review

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin's lymphoma, characterized by its aggressive nature and heterogeneity. Despite significant advances in understanding DLBCL pathogenesis, there is still a need to elucidate the intricate mechanisms involved in disease progression and identify novel therapeutic targets. Extracellular vesicles (EVs), including exosomes and microvesicles, have emerged as crucial mediators of intercellular communication in various physiological and pathological processes, including cancer. In recent years, evidence has suggested that EVs play a vital role in DLBCL biology by facilitating the exchange of genetic material, especially miRNAs, and proteins and lipids between tumor cells, immune cells, and the tumor microenvironment. We summarize and discuss the biological functions of EVs in DLBCL and their effects on the tumor microenvironment, highlighting their influence on DLBCL pathobiology, immune evasion, angiogenesis, and drug resistance. We also investigated EVs' diagnostic and prognostic potential as circulating biomarkers in DLBCL, emphasizing their utility in the non-invasive monitoring of the disease status and treatment response. Understanding the complex interplay between EVs and DLBCL may open up new avenues for personalized medicine, improve patient stratification, and facilitate the development of innovative therapeutic interventions in this devastating hematological malignancy.

Advances in tumor immunotherapy targeting macrophages

INTRODUCTION

In recent years, immunotherapy has shown significant therapeutic potential in patients with advanced tumors. However, only a small number of individuals benefit, mainly due to the tumor microenvironment (TME), which provides conditions for the development of tumors. Macrophages in TME, known as tumor-associated macrophages (TAM), are mainly divided into M1 anti-tumor and M2 pro-tumor phenotypes, which play a regulatory role in various stages of tumorigenesis, promote tumorigenesis and metastasis, and cause immunotherapy resistance.

AREAS COVERED

This review focuses on research strategies and preclinical/clinical research progress in translating TAM into antitumor phenotype by referring to the PubMed database for five years. These include small molecule chemotherapy drug development, metabolic regulation, gene editing, physical stimulation, nanotechnology-mediated combination therapy strategies, and chimeric antigen receptor-based immunotherapy.

EXPERT OPINION

It is necessary to explore the surface-specific receptors and cell signaling pathways of TAM further to improve the specificity and targeting of drugs and to strengthen research in the field of probes that can monitor changes in TAM in real time. In addition, the physical stimulation polarization strategy has the advantages of being noninvasive, economical, and stable and will have excellent clinical transformation value in the future.

Development of anti-cancer drugs for tumor-associated macrophages: a comprehensive review and mechanistic insights

This review provides an in-depth summary of the development of anti-cancer drugs for tumor-associated macrophages (TAMs), with a particular focus on the development and tissue specialization of macrophages, and factors influencing the polarization of M1 and M2 macrophages, and mechanistic insights underlying the targeting therapeutic approaches. TAMs, pivotal in the tumor microenvironment, exhibit notable plasticity and diverse functional roles. Influenced by the complex milieu, TAMs polarize into M1-type, which suppresses tumors, and M2-type, which promotes metastasis. Notably, targeting M2-TAMs is a promising strategy for tumor therapy. By emphasizing the importance of macrophages as a therapeutic target of anti-cancer drugs, this review aims to provide valuable insights and research directions for clinicians and researchers.

From tumor microenvironment to emerging biomarkers: the reshaping of the esophageal squamous cell carcinoma tumor microenvironment by neoadjuvant chemotherapy combined with immunotherapy

Esophageal squamous cell carcinoma is a cancer with high morbidity and mortality. The advent of immune checkpoint inhibitors has significantly increased complete response rates and postoperative R0 resection rates after neoadjuvant therapy. These drugs can largely reverse the suppression of the immune system caused by the tumor microenvironment, allowing the reactivation of anti-tumor immune infiltrating cells, significantly improving the patient's tumor microenvironment, and thus preventing tumor development. However, there are still some patients who respond poorly to neoadjuvant combined immunotherapy and cannot achieve the expected results. It is now found that exploring changes in the tumor microenvironment not only elucidates patient responsiveness to immunotherapy and identifies more reliable biomarkers, but also addresses the limitations of prediction with imaging examination such as CT and the instability of existing biomarkers. In light of these considerations, this review aims to delve into the alterations within the tumor microenvironment and identify potential predictive biomarkers ensuing from neoadjuvant immunotherapy in the context of esophageal squamous cell carcinoma.

YAP1 induces bladder cancer progression and promotes immune evasion through IL-6/STAT3 pathway and CXCL deregulation

The Hippo signaling pathway plays a key role in tumorigenesis in different cancer types. We investigated the role of the Hippo effector YAP1 in the tumor immune microenvironment (TIME) of urothelial carcinoma of the bladder (UCB) and evaluated the efficacy of immunotherapy in the context of YAP1 signaling. We performed numerous in vitro and in vivo experiments to determine the role of YAP1 using genetic and pharmacological attenuation of YAP1 activity. Briefly, RNA sequencing was carried out with mouse and human cell lines to identify novel YAP1-regulated downstream targets unbiasedly. We then experimentally confirmed that YAP1 regulates the TIME through the IL-6/STAT3 signaling pathway and varied C-X-C motif chemokine regulation. We analyzed several human sample sets to explore the TIME status in the context of YAP1 expression. Our data indicate that YAP1 attenuation decreases M2 macrophages and myeloid-derived suppressor cells in the TIME compared with YAP1-expressing cells. In summary, this study provides insights into YAP1 signaling as a driver for cancer stemness and an inducer of immunosuppressive TIME. Moreover, the therapeutic efficacy of YAP1 attenuation indicates that combined blockade of YAP1 and immune checkpoints may yield clinical value for treating patients with UCB.

Prognostic value of tumor-infiltrating lymphocyte subtypes and microorganisms in triple-negative breast cancer

ABSTRACT

Tumor-infiltrating lymphocytes (TILs) are key components of the tumor microenvironment (TME) and serve as prognostic markers for breast cancer. Patients with high TIL infiltration generally experience better clinical outcomes and extended survival compared to those with low TIL infiltration. However, as the TME is highly complex and TIL subtypes perform distinct biological functions, TILs may only provide an approximate indication of tumor immune status, potentially leading to biased prognostic results. Therefore, we reviewed the interactions between immune-infiltrating subtypes and tumor cells throughout the entire TME. By examining the antitumor or protumor effects of each TIL subtype, we aimed to better characterize the tumor immune landscape, offering more accurate and comprehensive insights for guiding triple-negative breast cancer (TNBC) treatment. In addition, this approach could lead to the development of new therapeutic targets, enabling tailored treatment strategies and precision medicine. Accumulating evidence suggests that the intestinal microbiome and its metabolites influence antitumor responses by modulating innate and adaptive immunity, with specific bacteria potentially serving as biomarkers for predicting clinical responses. Various studies have identified microorganisms in breast tissue, previously considered sterile, revealing differences in breast microbial composition between patients with breast cancer and controls, as well as associations between specific breast microorganisms and clinicopathologic features, including immune correlations. The aim of this review was to provide a more comprehensive set of prognostic markers for TNBC and to tap into potential-specific therapeutic targets.

CKAP2 Regulated by TFDP1 Promotes Metastasis and Proliferation of Colorectal Cancer through Affecting the Tumor Microenvironment

The current pathological and physiological evaluation system for colorectal cancer (CRC) is limited; thus, effective biological targets to diagnose and treat this disease are urgently needed. In this study, we used qRT-PCR for detecting mRNA levels of genes. The levels of protein were identified by western blot, immunohistochemistry, and immunofluorescence assays. In addition, functional experiments were used to evaluate the role of cytoskeleton associated protein (CKAP) 2 in CRC cells and human umbilical vein endothelial cells (HUVECs). Bioinformatics analysis was employed to predict the binding relationship of CKAP2 and TFDP1, which was confirmed through dual luciferase reporter assay and immunoprecipitation assay. Furthermore, we injected human colorectal carcinoma HCT116 cells into mice flanks, and we injected Luciferase-labeled HCT116 cells into mice tail vein. HE staining was used to detect tumor nodules. As a result, high CKAP2 expression was found in CRC cells and tissues. CKAP2 silencing reduced CRC cell migration, invasion, proliferation, and epithelial-mesenchymal transition. Moreover, CKAP2 expression was positively associated with M2 macrophage levels. CKAP2 promoted protein expression of CD86, CD206, IL-1β, and CCL17. Moreover, CKAP2 promoted the proliferation of HUVECs and angiogenesis via affecting the tumor microenvironment (TME). We also found that CKAP2 could interact with TFDP1. The inhibitory impacts of TFDP1 downregulation on CRC cell' proliferation, migration, and invasion were reversed via CKAP2 overexpression. In vivo silencing of CKAP2 repressed tumor growth and metastasis. Overall, CKAP2 was positively regulated by TFDP1, which promoted tumorigenesis and metastasis in CRC.

BAMBI Is a Prognostic Biomarker Associated with Macrophage Polarization, Glycolysis, and Lipid Metabolism in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common types of cancer worldwide. Affected patients have poor prognoses due to high rates of post-surgical recurrence and metastasis. Bone morphogenetic protein and activin membrane-bound inhibitor (BAMBI) reportedly contributes to the development and progression of various human cancers. Thus far, there have been no comprehensive studies regarding the expression of BAMBI in HCC; similarly, no studies have investigated the prognostic significance of BAMBI and its associated mechanisms in HCC. In this study, we analyzed the expression profiles of BAMBI, along with its contributions to pathological findings, metastasis characteristics, and prognosis, in multiple human cancers. We found that upregulation of BAMBI was associated with poor prognosis in HCC. Next, we explored the associations of BAMBI with multiple cell signaling pathways, immune cells, and immune checkpoints in HCC. The results showed that BAMBI was associated with tumor proliferation, epithelial-mesenchymal transition (EMT) markers, glycolysis, fatty acid biosynthesis and degradation pathways, and immune checkpoint regulation in HCC. In vitro and in vivo experiments showed that BAMBI promoted polarization of M1 macrophages and is linked to the expression of key genes involved in glycolipid metabolism. Furthermore, protein-protein interaction analysis suggested that BAMBI plays multiple roles in HCC by regulating genes in the transforming growth factor (TGF)-β and Wnt signaling pathways. Our findings elucidated that BAMBI is a prognostic biomarker and is associated with macrophage polarization, glycolysis, and lipid metabolism in HCC.

IL-33 in cancer immunotherapy: Pleiotropic functions and biological strategies

Interleukin-33 (IL-33) belongs to the IL-1 cytokine superfamily and plays a critical role in regulating immune responses and maintaining host homeostasis. IL-33 is essential for driving and enhancing type 2 immune responses and is closely associated with the pathogenesis of various inflammatory diseases, infections, and the progression and metastasis of cancers. This study aimed to provide an overview of the anti-tumor effects of IL-33 by examining its complex immunomodulatory functions within the tumor microenvironment and how it regulates immune cells to mediate these effects. We also provided perspectives on the pleiotropic roles of IL-33 in immunomodulation, its potential use in cancer immunotherapies, and possible adverse effects associated with its therapeutic application. Understanding these mechanisms is crucial for developing more effective IL-33-based diagnostic and therapeutic strategies.

GLN2 as a key biomarker and therapeutic target: evidence from a comprehensive pan-cancer study using molecular, functional, and bioinformatic analyses

BACKGROUND

GNL2, a nuclear protein, is involved in ribosome production and cell cycle regulation. However, its expression and function in different types of tumors are not well understood. Comprehensive studies across multiple cancer types are needed to assess the potential of GNL2 as a diagnostic, prognostic, and immunological marker.

METHODS

mRNA expression data, copy number alteration threshold data, masked copy number segmentation data, and DNA methylation 450 K data from The Cancer Genome Atlas (TCGA) pan-cancer cohort were obtained from the Firehose database. Additional data, including miRNA, The Cancer Proteome Atlas (TCPA), mutation data, and clinical information, were sourced from the University of California Santa Cruz (UCSC) Xena database. The cBioPortal database facilitates the examination of GNL2 mutation frequency, location, and 3D structure in the TCGA database. Gene Expression Omnibus (GEO) data verified the transcriptome level expression in the TCGA cohort. Protein expression levels were analyzed via the Human Protein Atlas (HPA) database and the Clinical Proteomic Tumor Analysis Consortium (CPTAC) database. Gene set enrichment analysis (GSEA) was employed to investigate the biological role of GNL2 across cancers. Multiple immune infiltration algorithms from the TIMER2.0 database were utilized to examine the correlation between GNL2 expression and the tumor immune microenvironment. The transcriptome-wide immune infiltration results were validated using 72 single-cell datasets from the Tumor Immune Single-cell Hub (TISCH) database. Pan-cancer survival maps were constructed, and GNL2 expression in different molecular subtypes across cancers was examined. The relationship between GNL2 and drug resistance was investigated using data from CellMiner, GDSC, and CTRP. The Comparative Toxicogenomics Database (CTD) was used to identify chemicals affecting GNL2 expression.

RESULTS

GNL2 is located primarily in the nucleus, and its expression is regulated mainly through somatic copy number alteration (SCNA) and aberrant DNA methylation, according to TCGA data. Database analysis and immunohistochemical results from clinical samples revealed high GNL2 expression in most tumors, which was correlated with diagnostic significance. High GNL2 expression often indicates a poor prognosis with pan-cancer prognostic value. Gene set enrichment analysis (GSEA) suggested that GNL2 is involved in tumor development through cell proliferation-related pathways. GNL2 expression is correlated with the expression of immune-related genes and the infiltration levels of multiple immune cells. The relationships between GNL2 and various drugs and chemicals were examined, revealing its influence on drug sensitivity and identifying five chemicals countering GNL2-mediated pro-cancer effects.

CONCLUSION

Comprehensive bioinformatics analysis of GNL2 in pan-cancer tissues, combined with experimental validation, elucidated the pan-cancer expression pattern of GNL2, determined its diagnostic and prognostic value, and explored the biological functions of GNL2. GNL2 may be involved in the regulation of cell cycle progression and remodeling of the tumor microenvironment and is associated with poor prognosis as a risk factor in most tumors. The potential of GNL2-based cancer therapies is emphasized, assisting in predicting the response to chemotherapy.

Tumor microenvironment remodeling after neoadjuvant chemoradiotherapy in local advanced rectal cancer revealed by single-cell RNA sequencing

BACKGROUND

The use of neoadjuvant chemoradiotherapy (neoCRT) followed by surgery has markedly enhanced the quality of survival in patients suffering from local advanced rectal cancer (LARC). Enhancing this treatment requires a deep understanding of its underlying mechanism. The heterogeneous nature of the tumor microenvironment (TME) significantly impacts therapeutic responses, presenting complex therapeutic challenges.

METHODS

In this comprehensive study, we explored the intricate cellular and molecular shifts within the TME of LARC after neoCRT administration. Using single-cell transcriptomic analysis, we meticulously examined 32,417 cells sourced from six samples, each representing different tumor regression grades (TRG: 0 versus 2). This detailed analysis enabled us to characterize the various cell subpopulations, encompassing epithelial cells, lymphocytes, myeloid cells, endothelial cells, and fibroblasts. Additionally, we identified their marker genes for deconvolution calculation in the READ cohort of the TCGA project. And we obtain their marker genes for deconvolution calculation in the READ cohort of the TCGA project.

RESULTS

Through cluster analysis and pathway comparisons of malignant tumor cells, we discerned that samples with poor tumor regression exhibit enhanced metabolic versatility and adaptability, enabling them to counteract the impacts of both radiotherapy and chemotherapy. Interestingly, within the TRG2 cohort, we observed a predominant immunosuppressive state in the TME, characterized by the activation of CD4 + regulatory T cells, maintained CD8 + T cell functionality, and a heightened M1 to M2 macrophage ratio. Moreover, the differing outcomes of neoCRT were reflected in the varying interaction dynamics between macrophages (M1 and M2) and CD4+/CD8 + T cells. Furthermore, our data reveal that neoCRT intricately modulates fibroblasts and endothelial cells, primarily through the extracellular matrix remodeling pathway, which orchestrates tumor angiogenesis. All changes were validated through immunofluorescence staining on intraoperative samples before and after treatment. To summarize, our investigation presents a comprehensive exploration of the cellular and molecular metamorphoses within the TME post-neoCRT.

CONCLUSIONS

By unveiling the sophisticated interaction between the multifaceted cells within the TME and their respective reactions to neoCRT, we establish a robust platform for ensuing future investigations. This study paves the way for novel therapeutic strategies that leverage these insights to bolster the efficacy of neoCRT in managing LARC.

Myc-mediated inhibition of HIF1a degradation promotes M2 macrophage polarization and impairs CD8 T cell function through lactic acid secretion in ovarian cancer

Ovarian cancer, the eleventh most prevalent cancer among women and a significant cause of cancer-related mortality, poses considerable challenges. While the Myc oncogene is implicated in diverse cancers, its impact on tumours expressing Myc during immune therapy processes remains enigmatic. Our study investigated Myc overexpression in a murine ovarian cancer cell line, focusing on alterations in HIF1a function. Seahorse experiments were utilized to validate metabolic shifts post-Myc overexpression. Moreover, we explored macrophage polarization and immunosuppressive potential following coculture with Myc-overexpressing tumour cells by employing Gpr132-/- mice to obtain mechanistic insights. In vivo experiments established an immune-competent tumour-bearing mouse model, and CD8 T cell, Treg, and macrophage infiltration post-Myc overexpression were evaluated via flow cytometry. Additionally, adoptive transfer of OTI CD8 T cells was conducted to investigate antigen-specific immune response variations after Myc overexpression. The findings revealed a noteworthy delay in HIF1a degradation, enhancing its functionality and promoting the classical Warburg effect upon Myc overexpression. Lactic acid secretion by Myc-overexpressing tumour cells promoted Gpr132-dependent M2 macrophage polarization, leading to the induction of macrophages capable of significantly suppressing CD8 T cell function. Remarkably, heightened macrophage infiltration in tumour microenvironments post-Myc overexpression was observed alongside impaired CD8 T cell infiltration and function. Interestingly, CD4 T-cell infiltration remained unaltered, and immune-suppressive effects were alleviated when Myc-overexpressing tumour cells were administered to Gpr132-/- mice, shedding light on potential therapeutic avenues for ovarian cancer management.

Up-Regulated Expression of Thioredoxin-Interacting Protein (TXNIP) in Mesenchymal Stem Cells Associated with Severe Aplastic Anemia in Children

The pathogenic mechanisms of severe aplastic anemia (SAA) in children are not completely elucidated. The insufficiency of the bone marrow microenvironment, in which mesenchymal stem cells (MSCs) are an important element, can be a potential factor associated with hematopoietic impairment in SAA. In the present study, we compared bone marrow MSCs from five children with SAA and five controls. We found a higher intensity of senescence-associated β-galactosidase activity in SAA MSCs, indicating the increased senescence in these cells. Further RNA sequencing analysis identified a distinctive profile of transcriptomes in SAA MSCs. After conducting a survey of the differentially expressed genes, we found that the up-regulated expression of TXNIP may compromise the proliferative potential of MSCs and probably relate to the pathogenesis of SAA. These results were validated by qPCR. To explore the molecular mechanism involving aberrant TXNIP regulation in SAA MSCs, the expression levels of IGF-1 and IGFBP-1 were measured. A significant increase in IGFBP-1 expression was noted in SAA MSCs despite the wide range of IGF-1 expressions. Accordingly, we postulated a novel pathogenic mechanism of SAA: a compensated increase in the expression of IGF-1 in MSCs to down-regulate TXNIP expression in the face of SAA, which is offset by the up-regulated expression of IGFBP-1.

Natural compounds modulate the mechanism of action of tumour-associated macrophages against colorectal cancer: a review

Colorectal cancer (CRC) exhibits a substantial morbidity and mortality rate, with its aetiology and pathogenesis remain elusive. It holds significant importance within the tumour microenvironment (TME) and exerts a crucial regulatory influence on tumorigenesis, progression, and metastasis. TAMs possess the capability to foster CRC pathogenesis, proliferation, invasion, and metastasis, as well as angiogenesis, immune evasion, and tumour resistance. Furthermore, TAMs can mediate the prognosis of CRC. In this paper, we review the mechanisms by which natural compounds target TAMs to exert anti-CRC effects from the perspective of the promotional effects of TAMs on CRC, mainly regulating the polarization of TAMs, reducing the infiltration and recruitment of TAMs, enhancing the phagocytosis of macrophages, and regulating the signalling pathways and cytokines, and discuss the potential value and therapeutic strategies of natural compounds-targeting the TAMs pathway in CRC clinical treatment.

Immune dynamics shaping pre-metastatic and metastatic niches in liver metastases: from molecular mechanisms to therapeutic strategies

Liver metastases are commonly detected in the advanced stages of various malignant tumors, representing a significant clinical challenge. Throughout the process of liver metastases formation, immune cells play a pivotal role, particularly in the pre-metastatic and metastatic niches within the liver. Immune cells establish extensive and intricate interactions with tumor cells and other components in the liver, collectively promoting and sustaining the growth of liver metastases. Despite the limited efficacy of existing therapeutic modalities against some advanced liver metastases, novel immune-based treatment approaches are continuously being explored and validated. Building on the systematic elucidation of the immunosuppressive characteristics of liver metastases, we explored the potential of novel immunotherapies applicable to patients with liver metastases from multiple dimensions.

Harnessing Gene Editing Technology for Tumor Microenvironment Modulation: An Emerging Anticancer Strategy

Cancer is a multifaceted disease influenced by both intrinsic cellular traits and extrinsic factors, with the tumor microenvironment (TME) being crucial for cancer progression. To satisfy their high proliferation and aggressiveness, cancer cells always plunder large amounts of nutrients and release various signals to their surroundings, forming a dynamic TME with special metabolic, immune, microbial and physical characteristics. Due to the neglect of interactions between tumor cells and the TME, traditional cancer therapies often struggle with challenges such as drug resistance, low efficacy, and recurrence. Importantly, the development of gene editing technologies, particularly the CRISPR-Cas system, offers promising new strategies for cancer treatment. Combined with nanomaterial strategies, CRISPR-Cas technology exhibits precision, affordability, and user-friendliness with reduced side effects, which holds great promise for profoundly altering the TME at the genetic level, potentially leading to lasting anticancer outcomes. This review will delve into how CRISPR-Cas can be leveraged to manipulate the TME, examining its potential as a transformative anticancer therapy.

Synergistic integration of mRNA-LNP with CAR-engineered immune cells: Pioneering progress in immunotherapy

Chimeric antigen receptor T cell (CAR-T) therapy has emerged as a revolutionary approach in the treatment of malignancies. Despite its remarkable successes, this field continues to grapple with challenges such as scalability, safety concerns, limited therapeutic effect, in vivo persistence, and the need for precise control over CAR expression. In the post-pandemic era of COVID-19 vaccine immunization, the application of messenger RNA (mRNA) encapsulated within lipid nanoparticles (LNPs) has recently garnered significant attention as a potential solution to address these challenges. This review delves into the dynamic landscape of mRNA-LNP technology and its potential implications for CAR-engineered immune cell-based immunotherapy.

Blocking CX3CR1+ Tumor-Associated Macrophages Enhances the Efficacy of Anti-PD1 Therapy in Hepatocellular Carcinoma

The efficacy of immune checkpoint inhibitors in the treatment of hepatocellular carcinoma (HCC) remains limited, highlighting the need for further investigation into the mechanisms underlying treatment resistance. Accumulating evidence indicates that tumor-associated macrophages (TAM) within the tumor microenvironment demonstrate a key role in immune evasion and treatment resistance. This study explored the role of TAMs in the HCC tumor microenvironment. Our findings reveal that TAMs expressing CX3C motif chemokine receptor 1 (CX3CR1) induced T-cell exhaustion through IL27 secretion in orthotopic models of HCC following treatment with anti-PD1. Moreover, we identified prostaglandin E2 (PGE2), released by immune-attacked tumor cells, as a key regulator of TAM transition to a CX3CR1+ phenotype. To augment the therapeutic response to anti-PD1 therapy, we propose targeting CX3CR1+ TAMs in addition to anti-PD1 therapy. Our study contributes to the understanding of the role of TAMs in cancer immunotherapy and highlights potential clinical implications for HCC treatment. The combination of targeting CX3CR1+ TAMs with anti-PD1 therapy holds promise for enhancing the efficacy of immunotherapeutic interventions in patients with HCC.

Effect of tumor-derived extracellular vesicle-shuttled lncRNA MALAT1 on proliferation, invasion and metastasis of triple-negative breast cancer by regulating macrophage M2 polarization via the POSTN/Hippo/YAP axis

OBJECTIVES

Triple-negative breast cancer (TNBC) is the deadliest subtype of breast cancer (BC). Tumor-derived extracellular vesicles (EVs) trigger tumor progression by promoting M2 polarization. Some lncRNAs can be encapsulated into EVs for intercellular communication. Herein, we investigated the mechanism of TNBC-derived EV-shuttled lncRNA MALAT1 on macrophage polarization/tumorigenesis.

METHODS

BC-associated targeted EV-derived lncRNAs were screened. Tumor tissues/tissues adjacent to cancer of TNBC patients, and blood samples of all subjects were collected. MALAT1/POSTN mRNA levels in tumor tissues/tissues adjacent to cancer, and MALAT1 expression in EVs and its correlation with TNBC patient overall survival were assessed by RT-qPCR/Kaplan-Meier survival analysis/log-rank test. TNBC patient M2 infiltration was detected by flow cytometry. MALAT1/POSTN levels in EVs/macrophages were regulated by transfection. Hippo/YAP activation was determined by Western blot. Nude mouse xenograft model was established and metastasis was detected by H&E staining.

RESULTS

MALAT1/POSTN were up-regulated and correlated with M2 infiltration/poor prognosis in TNBC patients. TNBC-derived EVs induced M2 polarization. MALAT1 was highly expressed in TNBC-derived EVs and could be transferred to macrophages via EVs to induce M2 polarization. POSTN overexpression diminished the inhibitory effect of MALAT1 knockdown on M2 markers. EVs activated the Hippo/YAP pathway in macrophages. The Hippo/YAP pathway inhibition abrogated the effect of POSTN overexpression on M2 marker expression. TNBC-EV-derived MALAT1 facilitated M2 polarization, and thus promoting occurrence and metastasis of TNBC in vitro and in vivo.

CONCLUSIONS

TNBC-EV-derived MALAT1 activated the Hippo/YAP axis by up-regulating POSTN, thereby inducing M2 polarization to promote TNBC occurrence and metastasis in vivo.

Angiopoietin-Like Protein 2 Expression in Tumor Cells Supports Tumor-Associated Macrophage-Induced Tumor Progression in Esophageal Cancer

BACKGROUND

Tumor-associated macrophages (TAM), a major component of the tumor microenvironment, play key roles in tumor formation and progression; however, mechanisms underlying TAM-induced tumor progression are complex and not well known. We previously reported that tumor cell-derived angiopoietin-like protein 2 (ANGPTL2) functions as a tumor promoter in some cancer contexts.

METHODS

We examined ANGPTL2 expression in paraffin-embedded tumor samples from resected specimens of 221 patients with esophageal cancer. Patients were subdivided into four groups based on immunohistochemistry scores described above: ANGPTL2-low/TAM-low, ANGPTL2-low/TAM-high, ANGPTL2-high/TAM-low, and ANGPTL2-high/TAM-high groups. Gene expression datasets of esophageal cancer cell lines were obtained from the cancer cell line encyclopedia public database.

RESULTS

In this study, we demonstrate that TAM infiltration is associated with poor prognosis in patients with esophageal cancer whose tumor cells show relatively higher ANGPTL2 expression levels; however, TAM infiltration did not affect prognosis in patients with ANGPTL2-low-expressing esophageal cancer, suggesting that ANGPTL2 expression in esophageal cancer cells is required for TAM-induced tumor progression. Our analysis of public datasets indicates a potential positive correlation of ANGPTL2 expression levels with that of transforming growth factor (TGF)-β, a TAM-activating factor, in esophageal cancer cell lines.

CONCLUSION

We conclude that ANGPTL2 signaling in tumor cells supports TAM-induced tumor progression and contributes to poor prognosis in patients with esophageal cancer. These findings overall provide novel insight into pro-tumor ANGPTL2 functions and illustrate the essential role of cancer cell/TAM crosstalk in cancer progression.

Crosstalk between GBP2 and M2 macrophage promotes the ccRCC progression

Clear cell renal cell carcinoma (ccRCC) represents a highly heterogeneous kidney malignancy associated with the poorest prognosis. The metastatic potential of advanced ccRCC tumors is notably high, posing significant clinical challenges. There is an urgent imperative to develop novel therapeutic approaches to address ccRCC metastasis. Recent investigations indicated a potential association between GBP2 and tumor immunity. However, the precise functional role of GBP2 in the progression of ccRCC remains poorly understood. The present study revealed a strong correlation between GBP2 and M2 macrophages. Specifically, our findings demonstrated that the inhibition of GBP2 significantly impedes the migratory and invasive capabilities of ccRCC cells. We observed that the presence of M2 macrophages can reverse the effects of GBP2 knockdown on tumor cell migration and invasion. Mechanistically, we demonstrated that M2 macrophages promote the expression of the GBP2/p-STAT3 and p-ERK axis in tumor cells through the secretion of interleukin-10 (IL-10) and transforming growth factor-β (TGF-β), thereby substantially enhancing the migratory and invasive capacities of the tumor cells. Simultaneously, we have identified that GBP2 promotes the polarization of macrophages to the M2 phenotype by stimulating the secretion of interleukin-18 (IL-18). In summary, our investigation anticipates that the GBP2/IL-18/M2 macrophages/IL-10 and the TGF-β/GBP2, p-STAT3, p-ERK loop plays a crucial role in ccRCC metastasis. The collective findings from our research underscore the significant role of GBP2 in tumor immunity and emphasize the potential for modulating GBP2 as a promising therapeutic strategy for targeting ccRCC metastasis.

Hepatocellular carcinoma-specific epigenetic checkpoints bidirectionally regulate the antitumor immunity of CD4 + T cells

Hepatocellular carcinoma (HCC) is a highly malignant tumor with significant global health implications. The role of CD4+ T cells, particularly conventional CD4+ T cells (Tconvs), in HCC progression remains unexplored. Furthermore, epigenetic factors are crucial in immune regulation, yet their specific role in HCC-infiltrating Tconv cells remains elusive. This study elucidates the role of MATR3, an epigenetic regulator, in modulating Tconv activity and immune evasion within the HCC microenvironment. Reanalysis of the scRNA-seq data revealed that early activation of CD4+ T cells is crucial for establishing an antitumor immune response. In vivo and in vitro experiments revealed that Tconv enhances cDC1-induced CD8+ T-cell activation. Screening identified MATR3 as a critical regulator of Tconv function, which is necessary for antitumour activity but harmful when overexpressed. Excessive MATR3 expression exacerbates Tconv exhaustion and impairs function by recruiting the SWI/SNF complex to relax chromatin in the TOX promoter region, leading to aberrant transcriptional changes. In summary, MATR3 is an HCC-specific epigenetic checkpoint that bidirectionally regulates Tconv antitumour immunity, suggesting new therapeutic strategies targeting epigenetic regulators to enhance antitumour immunity in HCC.

Deciphering CD59: Unveiling Its Role in Immune Microenvironment and Prognostic Significance

BACKGROUND

CD59, a GPI-anchored membrane protein, protects cancer cells from complement-dependent cytotoxicity (CDC) by inhibiting the formation of the membrane attack complex (MAC). It has been demonstrated to be overexpressed in most solid tumors, where it facilitates tumor cell escape from complement surveillance. The role of CD59 in cancer growth and interactions between CD59 and immune cells that modulate immune evasion has not been well explored.

METHODS

Using cancer patient database from The Cancer Genome Atlas (TCGA) and other public databases, we analyzed CD59 expression, its prognostic significance, and its association with immune cell infiltration in the tumor microenvironment, identifying associated genomic and functional networks and validating findings with invitro cell-line experimental data.

RESULTS

This article describes the abundant expression of CD59 in multiple tumors such as cervical squamous cell carcinoma (CESC), kidney renal cell carcinoma (KIRC), glioblastoma multiforme (GBM), head and neck squamous cell carcinoma (HNSC), and stomach adenocarcinoma (STAD), as well as in pan-cancer, using The Cancer Genome Atlas (TCGA) database and confirmed using multiple cancer cell lines. The expression of CD59 significantly alters the overall survival (OS) of patients with multiple malignancies such as CESC, GBM, HNSC, and STAD. Further, the correlation between CD59 and Treg and/or MDSC in the tumor microenvironment (TME) has shown to be strongly associated with poor outcomes in CESC, GBM, HNSC, and STAD as these tumors express high FOXP3 compared to KIRC. Moreover, unfavorable outcomes were strongly associated with the expression of CD59 and M2 tumor-associated macrophage infiltration in the TME via the IL10/pSTAT3 pathway in CESC and GBM but not in KIRC. In addition, TGFβ1-dominant cancers such as CESC, GBM, and HNSC showed a high correlation between CD59 and TGFβ1, leading to suppression of cytotoxic T cell activity.

CONCLUSION

Overall, the correlation between CD59 and immune cells predicts its prognosis as unfavorable in CESC, GBM, HNSC, and STAD while being favorable in KIRC.

Integrated analysis reveals prognostic correlation and immune characteristics of a tumor-associated macrophage-based risk signature in triple-negative breast cancer

Background

Tumor-associated macrophages play a critical role in the progression and immune response of triple-negative breast cancer (TNBC). Our study aimed to explore the characteristics of tumor-associated macrophages (TAMs) in TNBC, construct a risk signature associated with TAM clusters, and verify its relationship with prognosis and immune-related characteristics.

Methods

Firstly, we identified four TAM clusters and determined prognosis-related clusters in TNBC based on the single-cell RNA sequencing (scRNA-seq) data. Subsequently, the TAM-related prognostic genes were obtained by the univariate Cox regression analysis and an 8-gene risk signature was then constructed by least absolute shrinkage and selection operator (LASSO) regression based on these TAM-related prognostic genes. Analyses of immune characteristics showed a significant association between the signature with stromal and immune scores, as well as some immune cells.

Results

Multivariate analysis revealed that the risk signature was an independent prognostic factor for TNBC, and its value in predicting immunotherapeutic outcomes was also confirmed. A novel nomogram integrating the stage and TAM-based risk signature was constructed, which exhibited favorable predictability and reliability in the prognosis prediction of TNBC. Finally, the increasing expression of GPR34 which is one of the eight hub genes was explored in TNBC by experiments including reverse-transcriptase polymerase chain reaction, western blot, and immunohistochemistry.

Conclusions

Our study may provide unique insights into obtaining independent prognostic factors, improving immunotherapeutic strategies, and identifying effective therapeutic targets for TNBC.