Emerging phagocytosis checkpoints in cancer immunotherapy

Ferroptosis meets inflammation: A new frontier in cancer therapy

Ferroptosis, an iron-dependent form of regulated cell death driven by lipid peroxidation, has emerged as a critical player in cancer pathogenesis. Concurrently, inflammation, a key biological response to tissue injury or infection, significantly influences cancer development and progression. The interplay between ferroptosis and inflammation represents a promising yet underexplored area of research. This review synthesizes recent advances in understanding the molecular mechanisms governing their interaction, emphasizing how ferroptosis triggers inflammatory responses and how inflammatory mediators, such as TNF-α, regulate ferroptosis through iron metabolism and lipid peroxidation pathways. Key molecular targets within the ferroptosis-inflammation axis, including GPX4, ACSL4, and the NF-κB signaling pathway, offer therapeutic potential for cancer treatment. By modulating these targets, it may be possible to enhance ferroptosis and fine-tune inflammatory responses, thereby improving therapeutic outcomes. Additionally, this review explores the broader implications of targeting the ferroptosis-inflammation interplay in disease treatment, highlighting opportunities for developing innovative strategies to combat cancer. By bridging the gap in current knowledge, this review provides a comprehensive resource for researchers and clinicians, offering insights into the therapeutic potential of this intricate biological relationship.

Targeting "don't eat me" signal: breast cancer immunotherapy

PURPOSE

Breast cancer ranks as the most prevalent cancer type impacting women globally, both in terms of incidence and mortality rates, making it a major health concern for females. There's an urgent requirement to delve into new cancer treatment methods to improve patient survival rates.

METHODS

Immunotherapy has gained recognition as a promising area of research in the treatment of breast cancer, with targeted immune checkpoint therapies demonstrating the potential to yield sustained clinical responses and improve overall survival rates. Presently, the predominant immune checkpoints identified on breast cancer cells include CD47, CD24, PD-L1, MHC-I, and STC-1, among others. Nevertheless, the specific roles of these various immune checkpoints in breast carcinogenesis, metastasis, and immune evasion have yet to be comprehensively elucidated. We conducted a comprehensive review of the existing literature pertaining to breast cancer and immune checkpoint inhibitors, providing a summary of findings and an outlook on future research directions.

RESULTS

This article reviews the advancements in research concerning each immune checkpoint in breast cancer and their contributions to immune evasion, while also synthesizing immunotherapy strategies informed by these mechanisms. Furthermore, it anticipates future research priorities, thereby providing a theoretical foundation to guide immunotherapy as a potential interventional approach for breast cancer treatment.

CONCLUSION

Knowledge of immune checkpoints will drive the creation of novel cancer therapies, and future breast cancer research will increasingly emphasize personalized treatments tailored to patients' specific tumor characteristics.

SLAMF8 regulates Fc receptor-mediated phagocytosis in mouse macrophage cells through PI3K-Akt signaling

Emerging studies have demonstrated that phagocytosis checkpoints, which promote tumor-mediated immune evasion, are potential targets for cancer immunotherapy. In this study, the TCGA colorectal cancer (CRC) dataset and our RNA sequencing dataset suggested that SLAMF8 expression is significantly positively correlated with the expression levels of multiple phagocytosis checkpoint molecules. In vitro, we confirmed that SLAMF8 significantly regulated the phagocytosis of mouse CRC cells. RNA sequencing revealed that the expression of genes that promote Fc receptor (FcR)-mediated phagocytosis, such as FCGR1, FCGR3, FCGR2b, FCGR4, and ITGAM, was significantly upregulated after SLAMF8 knockdown. The Kyoto Encyclopedia of Genes and Genomes (KEGG) results suggested that the significantly enriched signaling pathways after SLAMF8 knockdown or overexpression included the PI3K-Akt signaling pathway. The protein expression levels of p-PI3K and p-Akt were significantly increased after SLAMF8 knockdown. When PI3K inhibitors and Fc blockers were added after SLAMF8 knockdown, mouse macrophage phagocytosis, and FcR expression decreased. Our results suggest that SLAMF8 may impair FcR-mediated phagocytosis through the PI3K-Akt signaling pathway and negatively regulate the antitumor immune response.

Dual blockade of GSTK1 and CD47 improves macrophage-mediated phagocytosis on cancer cells

CD47 is a crucial anti-phagocytic signal in regulating macrophage responses and its manipulation offers the therapeutic potential in cancer treatment. However, in many cases, blockade of CD47 by itself is insufficient to activate macrophage effectively, indicating other unidentified phagocytosis-regulating factors to resist the macrophage activity. In this study, a genome-wide human CRISPR-Cas9 library was developed for comprehensive screening of phagocytosis-regulating factors in the context of CD47 blockade. The screening results identified GSTK1 as a potential anti-phagocytic signal counteracting the efficacy of CD47-based phagocytosis. The disruption of GSTK1 significantly increased the phagocytosis rate of cancer cells by macrophages in combination with anti-CD47 antibody. Further mechanism investigation unveiled that GSTK1 blockade increased the membrane exposure of calreticulin in different cancer cells, which might be the primary mechanism driving enhanced macrophage-mediated phagocytosis. To this end, siGSTK1-loaded nanoparticles (siGSTK1-LNPs) were designed to suppress the GSTK1 expression efficiently. The comparable phagocytosis efficacy was also observed when combining siGSTK1-LNPs with anti-CD47 antibody. Above all, GSTK1 blockade was identified as a promising and feasible stimulus for enhancing the effectiveness of anti-CD47 antibody, introducing a novel and effective combination approach in cancer immunotherapy.

Engineered macrophage nanoparticles enhance microwave ablation efficacy in osteosarcoma via targeting the CD47-SIRPα Axis: A novel Biomimetic immunotherapeutic approach

Osteosarcoma (OS) is a lethal bone tumor that primarily affects adolescents. OS is characterized by a high incidence of recurrence following surgical intervention, which is attributed to the presence of residual microscopic disease. Tumor-associated macrophages, which dominate the tumor microenvironment, often suppress immune responses and facilitate tumor progression and recurrence. This study developed an innovative nanotherapeutic approach by utilizing genetically engineered macrophage membranes with M1 polarization, stably overexpressing signal regulatory protein alpha (SIRPα), to encapsulate microwave-responsive nano-Prussian blue (SIRPα-M@nanoPB) nanoparticles. These nanoparticles induce tumor cell death selectively through hyperthermia and microwave dynamic effects upon targeted microwave irradiation. It is of critical importance to note that the enhancement of SIRPα on the nanoparticle surface actively targets and binds CD47 of tumor cells, thereby disrupting the "don't-eat-me" signal and effectively countering the immunosuppressive tumor environment. This action restores macrophage phagocytosis with M1 polarization, triggering potent immune responses. Our strategy holds considerable promise when it comes to improving the efficacy of microwave ablation through immune modulation, while reducing thermal damage to adjacent normal tissue and minimizing the risk of tumor recurrence. Thus, it offers a significant advancement in microwave therapies for patients with OS.

Increased Immune Infiltration and Improved Prognosis of Head and Neck Squamous Cell Carcinoma Associated with Reduced Ancient Ubiquitous Protein 1 Gene Expression

This study aimed to explore the molecular mechanism underlying the prognostic role of ancient ubiquitous protein 1 (AUP1) in head and neck squamous cell carcinoma (HNSCC) and its relationship with the tumor immune microenvironment. Various web resources were used to analyze the differential expression of AUP1 and its role in the HNSCC pathogenesis. A nomogram aimed at predicting 1-, 3-, and 5-year survival rates was developed based on the patient's clinicopathological characteristics and AUP1 expression pattern. Several algorithms and analytical tools were used to explore the correlation between AUP1 expression and sensitivity to immune checkpoint gene therapy by evaluating infiltrating immune cells in patients with HNSCC. Higher AUP1 mRNA and protein expression levels were observed in most tumors and HNSCC than in the normal tissues. High AUP1 expression was an independent predictive risk factor for the overall survival of patients as it was closely associated with the patients' T, M, clinical, and pathological stages and lymphovascular invasion in HNSCC. In conclusion, AUP1 is involved in the occurrence and progression of HNSCC, may be used as an independent prognostic factor in patients with HNSCC, and could serve as a potential intervention target to improve immunotherapy sensitivity in HNSCC.

Does high PD-L1 expression reduce the risk of relapse after definitive surgery in patients with oral cavity cancer?

BACKGROUND

Uncovering the molecular mechanisms of cancer pathogenesis is crucial for improving survival outcomes.

AIMS

This study investigates the impact of programmed death ligand 1 (PD-L1) expression on the risk of progression in patients with oral squamous cell carcinoma (OSCC).

MATERIALS AND METHODS

The retrospective study included adult patients diagnosed with OSCC between January 2012 and December 2023. PD-L1 expression in tissue removed by definitive surgery was evaluated using immunohistochemistry, and tumor proportion score (TPS) and combined positive score (CPS) were calculated. Survival analyses were performed to assess its prognostic implications.

RESULTS

Among the 96 patients, TPS and CPS were 20% or above in 52 (54.2%) and 65 (67.7%) cases, respectively. TPS ≥20% was associated with mucosal lip location, earlier disease stage, and decreased risk of progression. The multivariate Cox regression model revealed that stage III/IV disease (HR: 2.176, 95%CI: 1.085-4.376, p = .029) and TPS ≥20% (HR: 0.241, 95%CI: 0.066-0.879, p = .031) were independent risk factors for progression-free survival.

CONCLUSIONS

The study revealed that increased tumoral PD-L1 expression may reduce the risk of progression in patients with OSCC.

SIGNIFICANCE

These findings underscore the potential prognostic significance of PD-L1 expression in OSCC following surgical resection.

Progress of PD-1/PD-L1 immune checkpoint inhibitors in the treatment of triple-negative breast cancer

Triple-negative breast cancer (TNBC) is a highly heterogeneous cancer with substantial recurrence potential. Currently, surgery and chemotherapy are the main treatments for this disease. However, chemotherapy is often limited by several factors, including low bioavailability, significant systemic toxicity, inadequate targeting, and multidrug resistance. Immune checkpoint inhibitors (ICIs), including those targeting programmed death protein-1 (PD-1) and its ligand (PD-L1), have been proven effective in the treatment of various tumours. In particular, in the treatment of TNBC with PD-1/PD-L1 inhibitors, both monotherapy and combination chemotherapy, as well as targeted drugs and other therapeutic strategies, have broad therapeutic prospects. In addition, these inhibitors can participate in the tumour immune microenvironment (TIME) through blocking PD-1/PD-L1 binding, which can improve immune efficacy. This article provides an overview of the use of PD-1/PD-L1 inhibitors in the treatment of TNBC and the progress of multiple therapeutic studies. To increase the survival of TNBC patients, relevant biomarkers for predicting the efficacy of PD-1/PD-L1 inhibitor therapy have been explored to identify new strategies for the treatment of TNBC.

Targeting myeloid cells for hematological malignancies: the present and future

Hematological malignancies are a diverse group of cancers that originate in the blood and bone marrow and are characterized by the abnormal proliferation and differentiation of hematopoietic cells. Myeloid blasts, which are derived from normal myeloid progenitors, play a central role in these diseases by disrupting hematopoiesis and driving disease progression. In addition, other myeloid cells, including tumor-associated macrophages and myeloid-derived suppressor cells, adapt dynamically to the tumor microenvironment, where they can promote immune evasion and resistance to treatment. This review explores the unique characteristics and pathogenic mechanisms of myeloid blasts, the immunosuppressive roles of myeloid cells, and their complex interactions within the TME. Furthermore, we highlight emerging therapeutic approaches targeting myeloid cells, focusing on strategies to reprogram their functions, inhibit their suppressive effects, or eliminate pathological populations altogether, as well as the latest preclinical and clinical trials advancing these approaches. By integrating insights from these studies, we aim to provide a comprehensive understanding of the roles of myeloid cells in hematological malignancies and their potential as therapeutic targets.

USP13: A therapeutic target for combating tumorigenesis and antitumor therapy resistance

Ubiquitin-specific peptidase 13 (USP13) has emerged as a key regulator of proteins critical to the hallmarks of cancer, playing an essential role in cellular regulation. This deubiquitinating enzyme, often overexpressed in malignancies, wields its molecular scissors precisely, snipping ubiquitin tags to rescue oncoproteins from degradation. Our review highlights the dual role of USP13 in cancer biology: while it predominantly fuels tumor growth and metastasis, USP13 occasionally functions as a tumor suppressor. USP13 is as a formidable factor in cancer therapy, fortifying tumors against an arsenal of treatments. It bolsters DNA repair mechanisms, ignites prosurvival autophagy, and even reprograms cell lineages to evade targeted therapies. However, USP13 is also a promising target in the treatment of cancer. We highlight burgeoning strategies to neutralize USP13, from small molecule inhibitors to innovative protein degraders, which may disarm cancer resistance mechanisms. We also offer suggestions for future USP13 research, emphasizing the need for structural insights and more potent inhibitors. This review highlights the critical role of USP13 in cancer and underscores its potential as a therapeutic target for advancing cancer treatment.

CD47 as a potent target in cancer immunotherapy: A review

Cancer is the second-highest cause of death worldwide. Accordingly, finding new cancer treatments is of great interest to researchers. The current platforms to fight cancer such as chemotherapy, radiotherapy, and surgery are limited in efficacy, especially in the metastatic setting. In this war against cancer, the immune system is a powerful ally, but tumor cells often outsmart it through alternative pathways. Cluster of differentiation 47 (CD47), a protein that normally prevents healthy cells from being attacked by immune cells, is often overexpressed on cancer cells. This makes CD47 a prime target for immunotherapy. Blocking of CD47 has the potential to unleash the immune system's cell populations-such as myeloid cells, macrophages, and T cells-to allow the immune system to discover and destroy cancer cells more successfully. In this review, we aimed to provide the latest information and findings about the roles of CD47 in the regulation of various cellular pathways and, thus, the importance of CD47 as a potential target in cancer therapy.

Targeted release of a bispecific fusion protein SIRPα/Siglec-10 by oncolytic adenovirus reinvigorates tumor-associated macrophages to improve therapeutic outcomes in solid tumors

BACKGROUND

The pleiotropic roles of tumor-associated macrophages (TAMs) render them attractive targets in antitumor drug development. CD47/SIRPα (signal regulatory protein alpha) and CD24/Siglec-10 (sialic acid-binding immunoglobulin-like lectin 10) signaling pathways have been found to suppress macrophage phagocytosis of malignant cells. Systemic blockade of CD47/SIRPα has shown severe side effects. Intratumoral delivery of a CD47 inhibitor by oncolytic viruses (OVs) may circumvent this hurdle.

METHODS

To identify the characteristics of recombinant adenovirus (AdV)-SIRPα/Siglec-10, we conducted CCK8 assay, quantitative PCR, western blot, competitive binding assay, in vitro cytotoxicity assay, ELISA and phagocytosis assay. We investigated the antitumor immune responses of AdV-SIRPα/Siglec-10 using flow cytometry, various tumor-bearing mouse models, humanized tumor-bearing mouse models, immune cell depletion, RNA sequencing, and in vitro T cell activation assay.

RESULTS

Here, we developed a novel AdV encoding a fusion protein composed of the extracellular domains of murine or human SIRPα and Siglec-10 (SIRPα/Siglec-10), termed AdV-mSS or AdV-huSS. The SIRPα/Siglec-10 was effectively secreted by cells infected with AdV-mSS and functioned as a dual blocker of CD47 and CD24, thereby significantly enhancing macrophage phagocytosis. In a series of tumor models, including subcutaneous and ascitic H22 hepatocellular carcinoma (HCC), subcutaneous Hepa1-6 HCC, MC38 colorectal carcinoma, and Lewis lung carcinoma, AdV-mSS treatment markedly enhanced antitumor efficacy. Mechanistically, AdV-mSS reprogrammed TAMs toward an antitumor phenotype and enhanced the expression of major histocompatibility complex (MHC)-I/II, promoting CD8+T cell proliferation and activation. Depletion of either macrophages or CD8+T cells abrogated the antitumor efficacy of AdV-mSS. Similarly, in a humanized LM3 HCC mouse model, AdV-huSS significantly inhibited tumor growth and prolonged survival.

CONCLUSIONS

Dual SIRPα/Siglec-10 inhibitor delivered intratumorally by AdV not only reinvigorated the TAM-CD8+T cell axis but also potentially reduced the risk of off-target effects. Further investigation of AdV-huSS in patients with cancer is warranted in the near future.

Overcoming immunotherapy resistance in glioblastoma: challenges and emerging strategies

Glioblastoma (GBM) is the most common and aggressive primary brain tumor in adults, characterized by rapid proliferation, extensive infiltration, and significant intratumoral heterogeneity. Despite advancements in conventional treatments, including surgery, radiotherapy, and chemotherapy, the prognosis for GBM patients remains poor, with a median survival of approximately 15 months. Immunotherapy has emerged as a promising alternative; however, the unique biological and immunological features, including its immunosuppressive tumor microenvironment (TME) and low mutational burden, render it resistant to many immunotherapeutic strategies. This review explores the key challenges in GBM immunotherapy, focusing on immune evasion mechanisms, the blood-brain barrier (BBB), and the TME. Immune checkpoint inhibitors and CAR-T cells have shown promise in preclinical models but have limited clinical success due to antigen heterogeneity, immune cell exhaustion, and impaired trafficking across the BBB. Emerging strategies, including dual-targeting CAR-T cells, engineered immune cells secreting therapeutic molecules, and advanced delivery systems to overcome the BBB, show potential for enhancing treatment efficacy. Addressing these challenges is crucial for improving GBM immunotherapy outcomes.

Synergistic Antitumor Immunotherapy via Mitochondria Regulation in Macrophages and Tumor Cells by an Iridium Photosensitizer

Mitochondrial targeting has emerged as an attractive method for antitumor treatment. However, most of the mitochondria targeted drugs focused on inhibiting tumor cells, while their potential for activation of immune responses in the tumor microenvironment has rarely been described. In this study, we report a photosensitive iridium complex MitoIrL2, which enabled the simultaneous mitochondrial modulation of macrophages and tumor cells to achieve synergistic antitumor immunity. The adjustment of the mitochondrial respiratory chain, HIF-1α, and the NF-κB pathway in macrophages drove the metabolic reprogramming from oxidative phosphorylation (OXPHOS) to glycolysis, converting protumor M2 into the antitumor M1 phenotype. Downregulated expression of immunosuppressive checkpoint SIRPα has also been observed on macrophages. Meanwhile, the mitochondrial targeting MitoIrL2 enhanced the immunogenic cell death of tumor cells and reversed the immunosuppressive tumor microenvironment, which activated the systemic immune response and established long-term immune memory in vivo. This work illustrates a promising strategy to simultaneously regulate macrophages toward the antitumor phenotype and enhance immunogenic cell death in tumor cells for synergistic antitumor immunotherapy.

A protocol for high-throughput screening for small chemicals promoting macrophage-mediated tumor cell phagocytosis in mice

Macrophage-mediated phagocytosis has emerged as a pivotal mechanism for eliminating tumor cells within the realm of cancer immunotherapy. Here, we present a protocol for identifying small molecules that enhance phagocytosis in mice using a co-culture system comprising primary macrophages, cancer cells, and a blockade of phagocytic checkpoints. We describe steps for expressing enhanced green fluorescent protein-luciferase (eGFP-Luc) and producing bone marrow-derived macrophages (BMDMs). We then detail procedures for optimizing co-culture conditions for high-throughput screen (HTS) and executing HTS chemical identification. For complete details on the use and execution of this protocol, please refer to Cao et al. 1.

Small extracellular vesicles: crucial mediators for prostate cancer

Small extracellular vesicles (sEVs) play a critical role in the progression, diagnosis, and treatment of prostate cancer (PCa), particularly within the tumor microenvironment (TME). Acting as novel biomarkers and agents for targeted biological therapy, sEVs contribute significantly to improving patient survival. These vesicles transport a variety of biomolecules, including proteins, nucleic acids, and lipids, which are instrumental in remodeling the TME, facilitating intercellular communication, and influencing key processes such as tumor growth, metastasis, and therapy resistance. A thorough understanding of sEV heterogeneity, including their biogenesis, characteristics, and potential applications, is essential. Recent advances have illuminated the origins, formation processes, and molecular cargo of PCa-derived sEVs (PCa-sEVs), enhancing our understanding of their role in disease progression. Furthermore, sEVs show promise as diagnostic markers, with potential applications in early detection and prognostic assessment in PCa. Therapeutically, natural and engineered sEVs offer versatile applications, including drug delivery, gene therapy, and immunomodulation, underscoring their potential in PCa management. This review delves into the substantial potential of sEVs in clinical practices for PCa.

Super-resolution microscopy unveils the nanoscale organization and self-limiting clustering of CD47 in human erythrocytes

The transmembrane protein CD47, an innate immune checkpoint protein, plays a pivotal role in preventing healthy erythrocytes from immune clearance. Our study utilized stochastic optical reconstruction microscopy (STORM) and single-molecule analysis to investigate the distribution of CD47 on the human erythrocyte membrane. Contrary to previous findings in mouse erythrocytes, we discovered that CD47 exists in randomly distributed monomers rather than in clusters across the human erythrocyte membrane. Using secondary antibody-induced crosslinking, we found that CD47 aggregates into stable clusters within minutes. By comparing these STORM results with those of the fully mobile protein CD59 and the cytoskeleton-bound membrane protein glycophorin C under similar conditions, as well as devising two-color STORM co-labeling and co-clustering experiments, we further quantitatively revealed an intermediate, self-limiting clustering behavior of CD47, elucidating its fractional (∼14%) attachment to the cytoskeleton. Moreover, we report reductions in both the amount of CD47 and its clustering capability in aged erythrocytes, providing new insight into erythrocyte senescence. Together, the combination of STORM and secondary antibody-based crosslinking unveils the unique self-limiting clustering behavior of CD47 due to its fractional cytoskeleton attachment.

Emerging immunotherapies in osteosarcoma: from checkpoint blockade to cellular therapies

Osteosarcoma remains a highly aggressive bone malignancy with limited therapeutic options, necessitating novel treatment strategies. Immunotherapy has emerged as a promising approach, yet its efficacy in osteosarcoma is hindered by an immunosuppressive tumor microenvironment and resistance mechanisms. This review explores recent advancements in checkpoint blockade, cellular therapies, and combination strategies aimed at enhancing immune responses. We highlight key challenges, including tumor heterogeneity, poor immune infiltration, and the need for predictive biomarkers. By integrating immunotherapy with chemotherapy, radiotherapy, and targeted therapy, emerging approaches seek to improve treatment outcomes. This review provides a comprehensive analysis of the evolving landscape of osteosarcoma immunotherapy, offering insights into future directions and potential breakthroughs. Researchers and clinicians will benefit from understanding these developments, as they pave the way for more effective and personalized therapeutic strategies in osteosarcoma.

The dual role of chaperone-mediated autophagy in the response and resistance to cancer immunotherapy

Cancer immunotherapy has become a revolutionary strategy in oncology, utilizing the host immune system to fight malignancies. Notwithstanding major progress, obstacles such as immune evasion by tumors and the development of resistance still remain. This manuscript examines the function of chaperone-mediated autophagy (CMA) in cancer biology, focusing on its effects on tumor immunotherapy response and resistance. CMA is a selective degradation mechanism for cytosolic proteins, which is crucial for sustaining cellular homeostasis and regulating immune responses. By degrading specific proteins, CMA can either facilitate tumor progression in stressful conditions, or promote tumor suppression by removing oncogenic factors. This double-edged sword highlights the complexity of CMA in cancer progression and its possible effect on treatment results. Here we clarify the molecular mechanisms by which CMA can regulate the immune response and its possible role as a therapeutic target for improving the effectiveness of cancer immunotherapy.

Oxygen-delivery nanoparticles enhanced immunotherapy efficacy monitored by granzyme B PET imaging in malignant tumors

Limited treatment response and inadequate monitoring methods stand firmly before successful immunotherapy. Recruiting and activating immune cells in the hypoxic tumor microenvironment is the key to reversing immune suppression and improving immunotherapy efficacy. In this study, biomimetic oxygen-delivering nanoparticles (CmPF) are engineered for homologous targeting and hypoxia alleviation within the tumor environment. CmPF targets the tumor microenvironment and delivers oxygen to reduce hypoxia, thereby promoting immune cell activity at the tumor site. In addition, granzyme B-targeted positron emission tomography (PET) imaging is employed to monitor immune cell activity changes in response to immunotherapy efficacy in vivo. The combination of CmPF with carboplatin and PD-1 inhibitors significantly suppresses tumor growth by 2.4-fold, exhibiting the potential of CmPF to enhance the efficacy of immunotherapy. Immunohistochemistry further confirms increased expression of key immune markers, highlighting the reprogramming of the tumor microenvironment. This study demonstrates that hypoxia alleviation enhances tumor immunotherapy efficacy and introduces a non-invasive PET imaging method for dynamic, real-time assessment of therapeutic response.

The role of type I interferon signaling in myeloid anti-tumor immunity

Tumors often arise in chronically inflamed, and thus immunologically highly active niches. While immune cells are able to recognize and remove transformed cells, tumors eventually escape the control of the immune system by shaping their immediate microenvironment. In this context, macrophages are of major importance, as they initially exert anti-tumor functions before they adopt a tumor-associated phenotype that instead inhibits anti-tumor immune responses and even allows for sustaining a smoldering inflammatory, growth promoting tumor microenvironment (TME). Type I interferons (IFNs) are well established modulators of inflammatory reactions. While they have been shown to directly inhibit tumor growth, there is accumulating evidence that they also play an important role in altering immune cell functions within the TME. In the present review, we focus on the impact of type I IFNs on anti-tumor responses, driven by monocytes and macrophages. Specifically, we will provide an overview of tumor-intrinsic factors, which impinge on IFN-stimulated gene (ISG) expression, like the presence of nucleic acids, metabolites, or hypoxia. We will further summarize the current understanding of the consequences of altered IFN responses on macrophage phenotypes, i.e., differentiation, polarization, and functions. For the latter, we will focus on macrophage-mediated tumor cell killing and phagocytosis, as well as on how macrophages affect their environment by secreting cytokines and directly interacting with immune cells. Finally, we will discuss how type I IFN responses in macrophages might affect and should be considered for current and future tumor therapies.

Insights on the Role of Sialic Acids in Acute Lymphoblastic Leukemia in Children

Sialic acids serve as crucial terminal sugars on glycoproteins or glycolipids present on cell surfaces. These sugars are involved in diverse physiological and pathological processes through their interactions with carbohydrate-binding proteins, facilitating cell-cell communication and influencing the outcomes of bacterial and viral infections. The role of hypersialylation in tumor growth and metastasis has been widely studied. Recent research has highlighted the significance of aberrant sialylation in enabling tumor cells to escape immune surveillance and sustain their malignant behavior. Acute lymphoblastic leukemia (ALL) is a heterogenous hematological malignancy that primarily affects children and is the second leading cause of mortality among individuals aged 1 to 14. ALL is characterized by the uncontrolled proliferation of immature lymphoid cells in the bone marrow, peripheral blood, and various organs. Sialic acid-binding immunoglobulin-like lectins (Siglecs) are cell surface proteins that can bind to sialic acids. Activation of Siglecs triggers downstream reactions, including induction of cell apoptosis. Siglec-7 and Siglec-9 have been reported to promote cancer progression by driving macrophage polarization, and their expressions on natural killer cells can inhibit tumor cell death. This comprehensive review aims to explore the sialylation mechanisms and their effects on ALL in children. Understanding the complex interplay between sialylation and ALL holds great potential for developing novel diagnostic tools and therapeutic interventions in managing this pediatric malignancy.

The battle within: cell death by phagocytosis in cancer

The process by which living cells are phagocytosed and digested to death is called cell death by phagocytosis, a term that has just recently been generalized and redefined. It is characterized by the phagocytosis of living cells and the cessation of cell death by phagocytosis. Phagocytosis of dead cells is a widely discussed issue in cancer, cell death by phagocytosis can stimulate phagocytosis and stimulate adaptive immunity in tumors, and at the same time, do not-eat-me signaling is an important site for cancer cells to evade recognition by phagocytes. Therefore, we discuss in this review cell death by phagocytosis occurring in cancer tissues and emphasize the difference between this new concept and the phagocytosis of dead tumor cells. Immediately thereafter, we describe the mechanisms by which cell death by phagocytosis occurs and how tumors escape phagocytosis. Finally, we summarize the potential clinical uses of cell death by phagocytosis in tumor therapy and strive to provide ideas for tumor therapy.

The efferocytosis process in aging: Supporting evidence, mechanisms, and therapeutic prospects for age-related diseases

BACKGROUND

Aging is characterized by an ongoing struggle between the buildup of damage caused by a combination of external and internal factors. Aging has different effects on phagocytes, including impaired efferocytosis. A deficiency in efferocytosis can cause chronic inflammation, aging, and several other clinical disorders.

AIM OF REVIEW

Our review underscores the possible feasibility and extensive scope of employing dual targets in various age-related diseases to reduce the occurrence and progression of age-related diseases, ultimately fostering healthy aging and increasing lifespan. Key scientific concepts of review Hence, the concurrent implementation of strategies aimed at augmenting efferocytic mechanisms and anti-aging treatments has the potential to serve as a potent intervention for extending the duration of a healthy lifespan. In this review, we comprehensively discuss the concept and physiological effects of efferocytosis. Subsequently, we investigated the association between efferocytosis and the hallmarks of aging. Finally, we discuss growing evidence regarding therapeutic interventions for age-related disorders, focusing on the physiological processes of aging and efferocytosis.

CD47 is a tumor cell-derived exosomal signature and regulates tumor immune microenvironment and immunotherapy responses

BACKGROUND

The pathogenesis of ovarian cancer (OvCa) involves a complex interplay of genetic, environmental, and hormonal factors. With the in-depth exploration of tumor ecosystem, exosomes can mediate the immunological status of tumor microenvironment (TME). Therefore, we aimed to recognize the tumor-derived exosomes (TEXs) which can distinguish the immune-hot and cold tumors and reflect the immunotherapeutic responses.

METHODS

A large set of transcriptomic and single-cell RNA-sequencing (scRNA-seq) datasets were downloaded and used to analyze the expression pattern of CD47 and its immuno-correlations in OvCa and multiple epithelial cell carcinomas such as breast cancers. In addition, a pan-gynecological cancer cohort was used to validate the correlation between CD47 and the inflamed TME.

RESULTS

In the current study, we found that CD47 was a TEX signature and had no transcriptional differences among patients with different clinicopathological features. Moreover, CD47 expression was positively correlated with the activation of immunological signaling pathways and enrichment of immune cell subpopulations in OvCa. Furthermore, in breast cancer and gynecological cancers, CD47, specially expressed in tumor cells, also showed favorable ability to distinguish the immune-hot and cold carcinomas. Moreover, in immunotherapy cohorts of breast cancer and other epithelial cell carcinomas, patients with CD47-high phenotype were more sensitive to immunotherapy and tended to achieve remission after treatment. Results from the TMA showed that CD47 was upregulated in tumor tissues and positively correlated with CD8 level.

CONCLUSION

In conclusion, CD47 is associated with an inflammatory TME, immune-hot tumors, and sensitivity of immunotherapy, highlighting the values of CD47 in identifying immunological traits and an immunotherapeutic response.

Post-translational modifications in hepatocellular carcinoma: unlocking new frontiers in immunotherapy

Liver cancer, particularly hepatocellular carcinoma (HCC), is one of the most common and aggressive malignancies worldwide. Immunotherapy has shown promising results in treating HCC, but its efficacy is often limited by complex mechanisms of immune evasion. Post-translational modifications (PTMs) of proteins play a critical role in regulating the immune responses within the tumor microenvironment (TME). These modifications influence protein function, stability, and interactions, which either promote or inhibit immune cell activity in cancer. In this mini-review, we explore the diverse PTMs that impact immune evasion in liver cancer, including glycosylation, phosphorylation, acetylation, and ubiquitination. We focus on how these PTMs regulate key immune checkpoint molecules such as PD-L1, CTLA-4, and the TCR complex. Furthermore, we discuss the potential of targeting PTMs in combination with existing immunotherapies to enhance the effectiveness of treatment in HCC. Understanding the role of PTMs in immune regulation may lead to the development of novel therapeutic strategies to overcome resistance to immunotherapy in liver cancer.

A Dual Stimuli-Responsive Nanoimmunomodulator for Antitumor Synergy of Macrophages and T Cells

Only a minority of patients benefit from current T-cell-focused adaptive immunotherapies, underscoring the need to engage innate immune cells, particularly macrophages, for multilayered tumor control. However, high-efficacy therapeutics capable of orchestrating multiple immune cells remain scarce. Herein, a dual stimuli-responsive nanoimmunomodulator (6EPP@si) that caters specifically to the tumor microenvironment (TME) is presented for the antitumor synergy of macrophages and T cells. Using the functional polymer-based carrier, we co-deliver the endoplasmic reticulum (ER)-localized photosensitizer 6E and small interfering RNA targeting CD47 (siCD47) into breast tumors. Within the acidic and high-glutathione TME, 6EPP@si undergoes self-lysosome escape and nanocleavage for precise, on-demand drug release. Consequently, siCD47 released into the cytoplasm enables potent CD47 silencing, while the ER-targeted photosensitizer 6E induces immunogenic cell death through reactive oxygen species-based ER stress, triggering the release of damage-associated molecular patterns, including calreticulin surface translocation. 6EPP@si enhances macrophage phagocytosis by modulating both antiphagocytic and prophagocytic signals and also promotes antigen presentation to activate T cells. In orthotopic breast tumor and spontaneous lung metastatic tumor models, this combined approach demonstrates robust antitumor effects and effective antimetastatic immunity, offering a meaningful strategy to simultaneously activate multiple immune cells for enhancing cancer immunotherapy.

Microbes, macrophages, and melanin: a unifying theory of disease as exemplified by cancer

It is widely accepted that cancer mostly arises from random spontaneous mutations triggered by environmental factors. Our theory challenges the idea of the random somatic mutation theory (SMT). The SMT does not fit well with Charles Darwin's theory of evolution in that the same relatively few mutations would occur so frequently and that these mutations would lead to death rather than survival of the fittest. However, it would fit well under the theory of evolution, if we were to look at it from the vantage point of pathogens and their supporting microbial communities colonizing humans and mutating host cells for their own benefit, as it does give them an evolutionary advantage and they are capable of selecting genes to mutate and of inserting their own DNA or RNA into hosts. In this article, we provide evidence that tumors are actually complex microbial communities composed of various microorganisms living within biofilms encapsulated by a hard matrix; that these microorganisms are what cause the genetic mutations seen in cancer and control angiogenesis; that these pathogens spread by hiding in tumor cells and M2 or M2-like macrophages and other phagocytic immune cells and traveling inside them to distant sites camouflaged by platelets, which they also reprogram, and prepare the distant site for metastasis; that risk factors for cancer are sources of energy that pathogens are able to utilize; and that, in accordance with our previous unifying theory of disease, pathogens utilize melanin for energy for building and sustaining tumors and metastasis. We propose a paradigm shift in our understanding of what cancer is, and, thereby, a different trajectory for avenues of treatment and prevention.

Chimeric Peptide Functionalized Immunostimulant to Orchestrate Photodynamic Immunotherapeutic Effect by PD-L1 Deglycosylation and CD47 Inhibition

Breast cancer utilizes diverse immunosuppressive mechanisms to evade immune surveillance, thereby impairing immunotherapeutic effects. In this work, a chimeric peptide functionalized immunostimulant (designated as aGlyR) is fabricated to boost photodynamic immunotherapy through PD-L1 deglycosylation and CD47 inhibition. The photosensitizer protoporphyrin IX (PpIX) is conjugated to a PD-L1 deglycosylation peptide via a hydrophilic PEG8 linker, yielding the chimeric peptide Fmoc-K(PpIX)-PEG8-GFTATPPAPDSPQEP. This chimeric peptide could self-assemble into nanomicelles capable of encapsulating the CD47 inhibitor RRx-001, generating the multifunctional photodynamic immunostimulant aGlyR. In vitro and in vivo results indicate that the photodynamic therapy (PDT) of aGlyR could disrupt breast cancer cells and trigger immunogenic cell death (ICD), leading to the release of tumor-associated antigens (TAAs) and the activation of immunological cascades. Additionally, the chimeric peptide component of aGlyR results in the deglycosylation and degradation of PD-L1, which restores T cell-mediated immune activity. Concurrently, the release of RRx-001 blocks the CD47 pathway, disrupting the antiphagocytic signaling of breast cancer cells and activating innate immune responses. This synergistic immunomodulatory approach effectively reverses the complex immunosuppressive factors, significantly enhancing the immunotherapeutic effects of conventional treatments.

Advancements in cellular immunotherapy: overcoming resistance in lung and colorectal cancer

Immunotherapy has revolutionized cancer treatment, offering hope for patients with otherwise treatment-resistant tumors. Among the most promising approaches are cellular therapies, particularly chimeric antigen receptor T-cell (CAR-T) therapy, which has shown remarkable success in hematologic malignancies. However, the application of these therapies to solid tumors, such as lung and colorectal cancers, has faced significant challenges. Tumor resistance mechanisms-ranging from immune evasion, antigen loss, and immune checkpoint upregulation, to tumor microenvironment immunosuppression-remain major obstacles. This mini-review highlights the latest advancements in tumor immunotherapy, with a focus on cellular therapies, and addresses the resistance mechanisms that hinder their effectiveness in lung and colorectal cancers. We examine the evolution of CAR-T cell therapy, as well as the potential of engineered natural killer (NK) cells and macrophages in solid tumor treatment. The review also explores cutting-edge strategies aimed at overcoming resistance, including combination therapies, gene editing technologies, and nanotechnology for targeted drug delivery. By discussing the molecular, cellular, and microenvironmental factors contributing to resistance, we aim to provide a comprehensive overview of how these challenges can be overcome, paving the way for more effective, personalized immunotherapies in lung and colorectal cancer treatment.

Cell fusion as a driver of metastasis: re-evaluating an old hypothesis in the age of cancer heterogeneity

Numerous studies have investigated the molecular mechanisms and signalling pathways underlying cancer metastasis, as there is still no effective treatment for this terminal stage of the disease. However, the exact processes that enable primary cancer cells to acquire a metastatic phenotype remain unclear. Increasing attention has been focused on the fusion of cancer cells with myeloid cells, a phenomenon that may result in hybrid cells, so-called Tumour Hybrid Cells (THCs), with enhanced migratory, angiogenic, immune evasion, colonisation, and metastatic properties. This process has been shown to potentially drive tumour progression, drug resistance, and cancer recurrence. In this review, we explore the potential mechanisms that govern cancer cell fusion, the molecular mediators involved, the metastatic characteristics acquired by fusion-derived hybrids, and their clinical significance in human cancer. Additionally, we discuss emerging pharmacological strategies aimed at targeting fusogenic molecules as a means to prevent metastatic dissemination.

Immune checkpoint blockade in experimental bacterial infections

Immune checkpoint inhibitors designed to reinvigorate immune responses suppressed by cancer cells have revolutionized cancer therapy. Similarities in immune dysregulation between cancer and infectious diseases have prompted investigations into the role of immune checkpoints in infectious diseases, including the therapeutic potential of immune checkpoint blockade and drug repurposing. While most research has centered around viral infections, data for bacterial infections are emerging. This systematic review reports on the in vivo effect of immune checkpoint blockade on bacterial burden and selected immune responses in preclinical studies of bacterial infection, aiming to assess if there could be a rationale for using immunotherapy for bacterial infections. Of the 42 analyzed studies, immune checkpoint blockade reduced the bacterial burden in 60% of studies, had no effect in 28% and increased the bacterial burden in 12%. Findings suggest that the effect of immune checkpoint blockade on bacterial burden is context-dependent and in part relates to the pathogen. Further preclinical research is required to understand how the therapeutic effect of immune checkpoint blockade is mediated in different bacterial infections, and if immune checkpoint blockade can be used as an adjuvant to conventional infection management strategies.

Beyond cancer: The potential application of CD47-based therapy in non-cancer diseases

CD47 is an immune checkpoint widely regarded as a 'don't eat me' signal. CD47-based anti-cancer therapy has received considerable attention, with a significant number of clinical trials conducted. While anti-cancer therapies based on CD47 remain a focal point of interest among researchers, it is noteworthy that an increasing number of studies have found that CD47-based therapy ameliorated the pathological status of non-cancer diseases. This review aims to provide an overview of the recent progress in comprehending the role of CD47-based therapy in non-cancer diseases, including diseases of the circulatory system, nervous system, digestive system, and so on. Furthermore, we sought to delineate the promising mechanisms of CD47-based therapy in treating non-cancer diseases. Our findings suggest that CD47-based agents may exert their effect by regulating phagocytosis, regulating T cells, dendritic cells, and neutrophils, and regulating the secretion of cytokines and chemokines. Additionally, we put forward the orientation of further research to bring to light the potential of CD47 and its binding partners as a target in non-cancer diseases.

The Role of MATN3 in Cancer Prognosis and Immune Infiltration Across Multiple Tumor Types

Background: MATN3 is a member of the matrix protein family and is involved in the regulation of osteoarthritis as well as the development of gastric cancer. We investigated the role of MATN3 in pan-cancer and validated this result by in vitro experiments. Material and Methods: We applied multiple databases to explore the expression of MATN3 in 33 types of tumors. Kaplan-Meier survival analysis is performed to understand the effect of MATN3 on Prognostic value in patients with different cancer types. The TIMER database was applied to explore the relationship between MATN3 and immune checkpoint genes, immunomodulatory genes, and immune infiltration, the Sanger box was applied to explore the relationship between MATN3 and methylation, the Genomic Cancer Analysis database was utilized to explore the relationship between MATN3 expression and pharmacological sensitivity, and the STRING database was used to explore the co-expressed genes and to complete the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis. Data from The Cancer Genome Atlas as well as Genotype-Tissue Expression databases were statistically analyzed and visualized using the R software. Immunohistochemistry and Western blotting for detection of MATN3 expression. CCK-8 and clone formation were used to detect cell proliferation, Wound-healing assay and transwell invasion were used to detect cell migration and invasion ability. Results: MATN3 is overexpressed in most cancer types, indicating a poorer prognosis. It is closely linked to methylation, immunomodulatory genes, and immune checkpoint genes, contributing to immune infiltration in various cancer types. In vitro experiments showed that silencing MATN3 inhibited cell proliferation, migration, and invasion ability. Conclusions: MATN3 is involved in the immune infiltration of cancer and affects the prognosis of many cancer types, and can be used as an immune as well as prognostic biomarker for pan-cancer.

CD133+PD-L1+ cancer cells confer resistance to adoptively transferred engineered macrophage-based therapy in melanoma

Adoptive transfer of genetically or nanoparticle-engineered macrophages represents a promising cell therapy modality for treatment of solid tumor. However, the therapeutic efficacy is suboptimal without achieving a complete tumor regression, and the underlying mechanism remains elusive. Here, we discover a subpopulation of cancer cells with upregulated CD133 and programmed death-ligand 1 in mouse melanoma, resistant to the phagocytosis by the transferred macrophages. Compared to the CD133-PD-L1- cancer cells, the CD133+PD-L1+ cancer cells express higher transforming growth factor-β signaling molecules to foster a resistant tumor niche, that restricts the trafficking of the transferred macrophages by stiffened extracellular matrix, and inhibits their cell-killing capability by immunosuppressive factors. The CD133+PD-L1+ cancer cells exhibit tumorigenic potential. The CD133+PD-L1+ cells are further identified in the clinically metastatic melanoma. Hyperthermia reverses the resistance of CD133+PD-L1+ cancer cells through upregulating the 'eat me' signal calreticulin, significantly improving the efficacy of adoptive macrophage therapy. Our findings demonstrate the mechanism of resistance to adoptive macrophage therapy, and provide a de novo strategy to counteract the resistance.

An engineered α1β1 integrin-mediated FcγRI signaling component to control enhanced CAR macrophage activation and phagocytosis

Treatment of solid tumors remains difficult, and therefore there has been increased focus on chimeric antigen receptor macrophages (CAR-M) to challenge solid tumors. However, CAR domain design of of adoptive cell therapy, which leads to differences in antitumor activity and triggered antitumor potential, remains poorly understood for macrophages. We developed an α1β1 integrin-mediated Fc-gamma receptor I (FcγRI) signaling component for CAR-M specific activation and its antitumor potential. We evaluated CAR-M effects with α1β1 integrin-mediated FcγRI signaling (ACT CAR-M) on the activation and antitumor phagocytic response of macrophages in vitro. Subcutaneous tumor model in BALB/c mice and carcinomatosis model in immunodeficient mice were used to test the antitumor effect of ACT CAR-M compared with CD3ζ CAR-M. The α1β1 integrin-mediated FcγRI signaling engagement of CAR-M was associated with enhanced macrophage activation and specific phagocytosis in primary human macrophages, and significantly improved tumor control and survival in multiple cancer models when compared to CD3ζ CAR-M. RNA-sequencing suggested that α1β1 integrin-mediated FcγRI engagement increased antitumor immunity by enhancing pro-inflammatory M1 phenotype-associated pathways, such as Toll-like receptor signaling, tumor necrosis factor signaling, and IL-17 signaling. α1β1 integrin-mediated FcγRI signaling engagement markedly enhanced antitumor effects of CAR-M immunotherapy, which is proposed as an advanced engineering CAR domain material to expand the clinical application of CAR-M.

Specifically Editing Cancer Sialoglycans for Enhanced In Vivo Immunotherapy through Aptamer-Enzyme Chimeras

Immune checkpoint blockade (ICB) therapies have demonstrated remarkable clinical success in treating cancer. However, their objective response rate remains suboptimal because current therapies rely on limited immune checkpoints that fail to cover the multiple immune evasion pathways of cancer. To explore potential ICB strategies, we propose a glycoimmune checkpoint elimination (glycoICE) therapy based on targeted editing of sialoglycans on the tumor cell surface using an aptamer-enzyme chimera (ApEC). The ApEC can be readily generated via a one-step bioorthogonal procedure, allowing for large-scale and uniform production. It specifically targets and desialylates cancer cells, disrupting the sialoglycan-Siglec axis to activate immune cells and enhance immunotherapy efficacy, while its high tumor selectivity minimizes side effects from indiscriminate desialylation of normal tissues. Furthermore, the ApEC has the potential to be a versatile platform for specific editing of sialoglycans in different tumor models by adjusting the aptamer sequences to target specific protein markers. This research not only introduces a novel molecular tool for the effective editing of sialoglycans in complex environments, but also provides valuable insights for advancing DNA-based drugs towards in vivo and clinical applications.

Lovastatin-mediated pharmacological inhibition of Formin protein DIAPH1 suppresses tumor immune escape and boosts immunotherapy response

BACKGROUND

The immunosuppressive tumor microenvironment (TME) is a key characteristic of human cancer. Immunotherapy has emerged as a promising treatment strategy to overcome immune escape and has gained widespread use in recent years. In particular, the blockade of PD-1/PD-L1 interaction holds significant importance in oncotherapy. Combining anti-PD-1/PD-L1 with small molecule inhibitors targeting key pathways represents an emerging trend in therapeutic development.

METHODS

To validate our findings biologically, we employed qRT-PCR or Western blotting and immunofluorescence staining techniques to assess the expression levels of DIAPH1 and PD-L1 in cells. Additionally, CCK8 and clone formation assays were utilized to evaluate cell proliferation ability, while flow assays were conducted to detect apoptosis in T cells.

RESULTS

Knockdown of DIAPH1 restored the tumor-killing capacity of T cells, effectively suppressing tumor immune escape. We observed a highly positive correlation between the expression levels of DIAPH1 and 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), which can be competitively inhibited by lovastatin. Through Sybyl analysis followed by confirmation via micro scale thermophoresis, we identified lovastatin as a potential inhibitor targeting DIAPH1. Lovastatin downregulated DIAPH1 expression both in tumor cell lines and xenograft lung cancer tissues within a mouse lung cancer model. Furthermore, we found that lovastatin degraded DIAPH1 through lysosomal degradation pathway. Treatment with lovastatin was strongly associated with improved response rates and prolonged overall survival among patients with lung adenocarcinoma. Finally, overexpression of DIAPH1 reversed the inhibitory effects mediated by lovastatin on tumor development.

CONCLUSIONS

Lovastatin downregulates PD-L1 expression by targeting DIAPH1 and restores the tumor-killing ability of T cells to block tumor immune escape. Lovastatin may become a potential drug for cancer patients to enhance immunotherapy response in the clinic.

Infiltrating T lymphocytes and tumor microenvironment within cholangiocarcinoma: immune heterogeneity, intercellular communication, immune checkpoints

Cholangiocarcinoma is the second most common primary liver cancer, and its global incidence has increased in recent years. Radical surgical resection and systemic chemotherapy have traditionally been the standard treatment options. However, the complexity of cholangiocarcinoma subtypes often presents a challenge for early diagnosis. Additionally, high recurrence rates following radical treatment and resistance to late-stage chemotherapy limit the benefits for patients. Immunotherapy has emerged as an effective strategy for treating various types of cancer, and has shown efficacy when combined with chemotherapy for cholangiocarcinoma. Current immunotherapies targeting cholangiocarcinoma have predominantly focused on T lymphocytes within the tumor microenvironment, and new immunotherapies have yielded unsatisfactory results in clinical trials. Therefore, it is essential to achieve a comprehensive understanding of the unique tumor microenvironment of cholangiocarcinoma and the pivotal role of T lymphocytes within it. In this review, we describe the heterogeneous immune landscape and intercellular communication in cholangiocarcinoma and summarize the specific distribution of T lymphocytes. Finally, we review potential immune checkpoints in cholangiocarcinoma.

Efficiency and safety of HAIC combined with lenvatinib and tislelizumab for advanced hepatocellular carcinoma with high tumor burden: a multicenter propensity score matching analysis

Purpose

The present work focused on assessing whether hepatic arterial infusion chemotherapy (HAIC) combined with lenvatinib and tislelizumab was safe and effective on advanced hepatocellular carcinoma (HCC) showing high tumor burden.

Methods

In the present multicenter retrospective study, treatment-naive advanced HCC patients (BCLC stage C) showing high tumor burden (maximum diameter of intrahepatic lesion beyond 7 cm) treated with lenvatinib and tislelizumab with or without HAIC were reviewed for eligibility from June 2020 to June 2023. Baseline differences between groups were mitigated by propensity score matching (PSM). Our primary endpoint was overall survival (OS); and secondary endpoints included adverse events (AEs), progression-free survival (PFS), disease control rate (DCR) and objective response rate (ORR) according to RECIST 1.1 criteria, respectively.

Results

After eligibility reviewed, total 162 patients treated with lenvatinib and tislelizumab were enrolled: 63 patients with HAIC (HTP group), and the remaining 99 patients without HAIC (TP group). After PSM 1:1, 47 cases were evenly divided into each group. Of them, HTP group showed significant prolonged median OS compared with TP group (16.6 versus 21.0 months; hazard ratio [HR]: 0.26, 95% confidence interval [CI]: 0.35-0.98; p = 0.039), and median PFS of HTP group was also prolonged (8.9 versus 11.6 months; HR: 0.55, 95% CI: 0.34-0.87; p = 0.010). Higher DCR and ORR could be observed in HTP relative to TP groups (ORR: 53.2% versus 17.0%, p < 0.001; DCR: 87.2% versus 61.7%, p = 0.004). The severe AEs (grade 3/4) and all grades were comparable between the groups, while all of these AEs could be controlled, and AEs of grade 5 were not reported.

Conclusion

HAIC combined with lenvatinib and tislelizumab is the candidate treatment for advanced HCC patients because of its improved prognosis and acceptable safety.

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.

Exploring CAR-macrophages in non-tumor diseases: Therapeutic potential beyond cancer

BACKGROUND

After significant advancements in tumor treatment, personalized cell therapy based on chimeric antigen receptors (CAR) holds promise for transforming the management of various diseases. CAR-T therapy, the first approved CAR cell therapy product, has demonstrated therapeutic potential in treating infectious diseases, autoimmune disorders, and fibrosis. CAR-macrophages (CAR-Ms) are emerging as a promising approach in CAR immune cell therapy, particularly for solid tumor treatment, highlighting the feasibility of using macrophages to eliminate pathogens and abnormal cells.

AIM OF REVIEW

This review summarizes the progress of CAR-M therapy in non-tumor diseases and discusses various CAR intracellular activation domain designs and their potential to optimize therapeutic effects by modulating interactions between cellular components in the tissue microenvironment and CAR-M. Additionally, we discuss the characteristics and advantages of CAR-M therapy compared to traditional medicine and CAR-T/NK therapy, as well as the challenges and prospects for the clinical translation of CAR-M.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review provides a comprehensive understanding of CAR-M for the treatment of non-tumor diseases, analyzes the advantages and characteristics of CAR-M therapy, and highlights the important impact of CAR intracellular domain design on therapeutic efficacy. In addition, the challenges and clinical translation prospects of developing CAR-M as a new cell therapy are discussed.

HIF-1α Mediated Regulation of Glioblastoma Malignant Phenotypes through CD47 Protein: Understanding Functions and Mechanisms

Glioblastoma (GBM) is a highly invasive and malignant primary intracranial tumor originating from glial cells, and it is associated with an extremely poor clinical prognosis. The hypoxic conditions within GBM promote various tumor cell processes such as angiogenesis, proliferation, migration, invasion, and drug resistance. A key aspect of tumor adaptation to the hypoxic environment and the promotion of malignant behaviors is the regulation of HIF-1α signaling pathways. However, the specific pathogenic mechanisms involving HIF-1α in GBM have not been thoroughly investigated. This study reveals significant overexpression of both HIF-1α and CD47 in GBM. Patients with high HIF-1α levels and CD47 expression had significantly reduced overall survival and disease-free survival times. Furthermore, a positive correlation was observed between the expression levels of HIF-1α and CD47 in GBM. Lentivirus-mediated knockdown of HIF-1α protein and plasmid-based overexpression of CD47 protein simultaneously enhanced cell proliferation, clonogenic potential and cell migration abilities in GBM, and HIF-1α was found to regulate key pathways, including the P-PI3K/P-AKT, SOX2/OCT4 and MMP2/MMP9 pathways, in GBM.

NIR-II Photoacoustic Imaging-Guided Chemo-Photothermal Therapy Using PA1094T Combined with Anti-CD47 Antibody: Activating Pyroptosis against Orthotopic Glioblastoma

Treating glioblastoma (GBM) with single-agent chemotherapy is often ineffective due to inefficient drug delivery and the immunosuppressive tumor microenvironment, which leads to drug resistance. Strategies that activate programmed cell death mechanisms and repolarized tumor-associated macrophages toward an antitumoral M1-like phenotype can help reverse the immunosuppressive tumor microenvironment. In this study, a novel approach using NIR-II (1000-1700 nm) photoacoustic imaging (PAI)-guided chemo-photothermal therapy is presented. NIR-II imaging, with its superior tissue penetration and reduced background noise, enables precise tumor targeting. A targeted nano prodrug is developed using poly (lactic-co-glycolic acid) nanoparticles loaded with A1094 dye and temozolomide (TMZ), coupled with an anti-CD47 antibody. This system employs synergistic chemo-photothermal therapy activated by NIR-II light, inducing apoptosis, pyroptosis, and T-cell activation. PAI provides rapid, point-of-care GBM diagnosis, and highlighted the effective targeting of the PA1094T nanoplatform. In a recurrent GBM model, the combination of PA1094T and anti-CD47 antibody significantly enhances cancer cell phagocytosis and effectively remodels the immunosuppressive microenvironment, resulting in better therapeutic outcomes compared to conventional therapies. These results indicate that this NIR-II PAI-guided drug cocktail therapy is a promising strategy for treating GBM, potentially addressing drug resistance and improving treatment efficacy through enhanced targeting and immunomodulation.

Role of PI3Kγ in the polarization, migration, and phagocytosis of microglia

Phosphoinositide 3-kinase γ (PI3Kγ) is a signaling protein that is constitutively expressed in immune competent cells and plays a crucial role in cell proliferation, apoptosis, migration, deformation, and immunology. Several studies have shown that high expression of PI3Kγ can inhibit the occurrence of inflammation in microglia while also regulating the polarization of microglia to inhibit inflammation and enhance microglial migration and phagocytosis. It is well known that the regulation of microglial polarization, migration, and phagocytosis is key to the treatment of most neurodegenerative diseases. Therefore, in this article, we review the important regulatory role of PI3Kγ in microglia to provide a basis for the treatment of neurodegenerative diseases.

Enhanced Antiglioma Effect by a Vitamin D3-Inserted Lipid Hybrid Neutrophil Membrane Biomimetic Multimodal Nanoplatform

Glioblastoma, the most prevalent malignant brain tumor, is a lethal threat to human health, with aggressive and infiltrative growth characteristics that compromise the clinical treatment. Herein, we developed a vitamin D3-inserted lipid hybrid neutrophil membrane biomimetic multimodal nanoplatform (designated as NED@MnO2-DOX) through doxorubicin (DOX)-loaded manganese dioxide nanoparticles (MnO2) which were coated with a vitamin D3-inserted lipid hybrid neutrophil membrane. It was demonstrated that in addition to chemotherapy and chemo-dynamic therapy efficacy, NED@MnO2-DOX exhibited great power to activate and amplify immune responses related to the cGAS STING pathway, bolstering the secretion of type I interferon-β and proinflammatory cytokines, promoting the maturation of DC cells and infiltration of CD8+T cells into the glioma tissue, thereby reversing the immunosuppressive microenvironment of glioma from a "cold" tumor to a "hot" tumor. The biomimetic multimodal nanoplatform has potential as a multimodal strategy for glioma-targeted treatment, especially holding considerable promise for the development of innate immune therapy for glioma.

Nanotherapeutics for Macrophage Network Modulation in Tumor Microenvironments: Targets and Tools

Macrophage is an important component in the tumor immune microenvironment, which exerts significant influence on tumor development and metastasis. Due to their dual nature of promoting and suppressing inflammation, macrophages can serve as both targets for tumor immunotherapy and tools for treating malignancies. However, the abundant infiltration of tumor-associated macrophages dominated by an immunosuppressive phenotype maintains a pro-tumor microenvironment, and engineering macrophages using nanotechnology to manipulate the tumor immune microenvironment represent a feasible approach for cancer immunotherapy. Additionally, considering the phagocytic and specifically tumor-targeting capabilities of M1 macrophages, macrophages manipulated through cellular engineering and nanotechnology, as well as macrophage-derived exosomes and macrophage membranes, can also become effective tools for cancer treatment. In conclusion, nanotherapeutics targeting macrophages remains immense potential for the development of macrophage-mediated tumor treatment methods and will further enhance our understanding, diagnosis, and treatment of various malignants.

Improved survival with second-line hepatic arterial infusion chemotherapy after atezolizumab-bevacizumab failure in hepatocellular carcinoma

Background

There is no established second-line treatment for hepatocellular carcinoma (HCC) following atezolizumab-bevacizumab (ate-beva) failure. This study assessed the efficacy of hepatic arterial infusion chemotherapy (HAIC) as a salvage therapy by comparing survival outcomes and treatment responses between HAIC as a first-line treatment and as a second-line option after ate-beva failure.

Materials and Methods

We retrospectively analyzed 100 patients with advanced HCC treated with HAIC between March 2022 and July 2024. Patients were categorized into two groups: those who received HAIC as initial therapy (first-line HAIC group) and those who received HAIC following ate-beva failure (post-ate-beva group). Survival outcomes were assessed with Kaplan-Meier curves and log-rank tests, and factors associated with survival were identified through Cox regression analysis.

Results

The post-ate-beva group exhibited longer overall survival (OS) (median OS 12.4 months) compared to the first-line HAIC group (median OS 6.8 months) (p = 0.073). Progression-free survival (PFS) was significantly superior in the post-ate-beva group (median PFS 8.2 months) compared to the first-line HAIC group (median PFS 3.1 months) (p = 0.018). The objective response rate was also notably higher in the post-ate-beva group than in the first-line HAIC group (35.3% vs. 18.1%, p = 0.031). In multivariate analysis, HAIC following ate-beva failure, compared to first-line HAIC, was significantly associated with favorable outcomes for both OS (p = 0.014) and PFS (p = 0.006).

Conclusion

The superior survival outcomes and treatment responses observed in the post-ate-beva group suggest that HAIC may be an effective second-line treatment option for advanced HCC following ate-beva therapy failure. However, due to the retrospective nature and small sample size of the study, further prospective studies with larger patient populations are needed to strengthen the evidence.

Anaplastic Lymphoma Kinase (ALK) Inhibitors Enhance Phagocytosis Induced by CD47 Blockade in Sensitive and Resistant ALK-Driven Malignancies

BACKGROUND

Anaplastic lymphoma kinase (ALK) plays a role in the development of lymphoma, lung cancer and neuroblastoma. While tyrosine kinase inhibitors (TKIs) have improved treatment outcomes, relapse remains a challenge due to on-target mutations and off-target resistance mechanisms. ALK-positive (ALK+) tumors can evade the immune system, partly through tumor-associated macrophages (TAMs) that facilitate immune escape. Cancer cells use "don't eat me" signals (DEMs), such as CD47, to resist TAMs-mediated phagocytosis. TKIs may upregulate pro-phagocytic stimuli (i.e., calreticulin, CALR), suggesting a potential therapeutic benefit in combining TKIs with an anti-CD47 monoclonal antibody (mAb). However, the impact of this combination on both TKIs-sensitive and resistant ALK+ tumors requires further investigation.

METHODS

A panel of TKIs-sensitive and resistant ALK+ cancer subtypes was assessed for CALR and CD47 expression over time using flow cytometry. Flow cytometry co-culture and fluorescent microscopy assays were employed to evaluate phagocytosis under various treatment conditions.

RESULTS

ALK inhibitors increased CALR expression in both TKIs-sensitive and off-target resistant ALK+ cancer cells. Prolonged TKIs exposure also led to CD47 upregulation. The combination of ALK inhibitors and anti-CD47 mAb significantly enhanced phagocytosis compared to anti-CD47 alone, as confirmed by flow cytometry and fluorescent microscopy.

CONCLUSIONS

Anti-CD47 mAb can quench DEMs while exposing pro-phagocytic signals, promoting tumor cell phagocytosis. ALK inhibitors induced immunogenic cell damage by upregulating CALR in both sensitive and off-target resistant tumors. Continuous TKIs exposure in off-target resistant settings also resulted in the upregulation of CD47 over time. Combining TKIs with a CD47 blockade may offer therapeutic benefits in ALK+ cancers, especially in overcoming off-target resistance where TKIs alone are less effective.

Rituximab-IgG2 is a phagocytic enhancer in antibody-based immunotherapy of B-cell lymphoma by altering CD47 expression

Antibody-dependent cellular phagocytosis (ADCP) by monocytes and macrophages contributes significantly to the efficacy of many therapeutic monoclonal antibodies (mAbs), including anti-CD20 rituximab (RTX) targeting CD20+ B-cell non-Hodgkin lymphomas (NHL). However, ADCP is constrained by various immune checkpoints, notably the anti-phagocytic CD47 molecule, necessitating strategies to overcome this resistance. We have previously shown that the IgG2 isotype of RTX induces CD20-mediated apoptosis in B-cell lymphoma cells and, when combined with RTX-IgG1 or RTX-IgG3 mAbs, can significantly enhance Fc receptor-mediated phagocytosis. Here, we report that the apoptotic effect of RTX-IgG2 on lymphoma cells contributes to changes in the tumor cell's CD47 profile by reducing its overall expression and altering its surface distribution. Furthermore, when RTX-IgG2 is combined with other lymphoma-targeting mAbs, such as anti-CD59 or anti-PD-L1, it significantly enhances the ADCP of lymphoma cells compared to single mAb treatment. In summary, RTX-IgG2 acts as a potent phagocytic enhancer by promoting Fc-receptor mediated phagocytosis through apoptosis and reduction of CD47 in CD20+ malignant B-cells. RTX-IgG2 represents a valuable therapeutic component in enhancing the effectiveness of different mAbs targeting B-cell NHL.