Engineering nanoparticles boost TNBC therapy by CD24 blockade and mitochondrial dynamics regulation

Fundamental knowledge and research regarding the role of immunity in triple-negative breast cancer from 2014-2024: A bibliometric analysis

Immunity has vital research value and promising applications in triple-negative breast cancer (TNBC). Nevertheless, few bibliometric analyses have systematically investigated this area. This study aimed to comprehensively review the collaboration and impact of countries, institutions, authors, and journals on the role of immunity in TNBC from a bibliometric perspective, evaluate the keyword co-occurrence of the knowledge structure, and identify hot trends and emerging topics. Articles and reviews related to immunity in TNBC were retrieved from the Web of Science core collection using subject search. A bibliometric study was conducted primarily using CiteSpace and VOSviewer. A total of 3,104 articles and reviews were included from January 1, 2014, through December 31, 2024. The number of articles on immunization in TNBC is rising. These publications are mainly from 415 institutions in 82 countries, led by China and the USA. Among these publications, Lajos Pusztai published the most papers, while Peter Schmid was co-cited the most. The most productive journals focused on molecular biology, biological immunology, and clinical medicine. Furthermore, co-citation analysis revealed that tumor microenvironment, biomarkers, and immune checkpoint inhibitors are current and developing research areas. The keywords "immunotherapy" and "nanoparticles" are also likely to be new trends and focal points for future research. This study adopted bibliometric and visualization methods to provide a comprehensive review of the research on immunization in TNBC. This article will help researchers better understand the dynamic evolution of the role of immunity in TNBC and identify areas for future research.

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.

Extracellular vesicles in triple-negative breast cancer: current updates, challenges and future prospects

Breast cancer (BC) remains a complex and widespread problem, affecting millions of women worldwide, Among the various subtypes of BC, triple-negative breast cancer (TNBC) is particularly challenging, representing approximately 20% of all BC cases, and the survival rate of TNBC patients is generally worse than other subtypes of BC. TNBC is a heterogeneous disease characterized by lack of expression of three receptors: estrogen (ER), progesterone (PR), and human epidermal growth factor receptor 2 (HER2), resulting conventional hormonal therapies are ineffective for its management. Despite various therapeutic approaches have been explored, but no definitive solution has been found yet for TNBC. Current treatments options are chemotherapy, immunotherapy, radiotherapy and surgery, although, these therapies have some limitations, such as the development of resistance to anti-cancer drugs, and off-target toxicity, which remain primary obstacles and significant challenges for TNBC. Several findings have shown that EVs exhibit significant therapeutic promise in many diseases, and a similar important role has been observed in various types of tumor. Studies suggest that EVs may offer a potential solution for the management of TNBC. This review highlights the multifaceted roles of EVs in TNBC, emphasizing their involvement in disease progression, diagnosis and therapeutic approach, as well as their potential as biomarkers and drug delivery.

Celastrol-loaded ginsenoside Rg3 liposomes enhance anti-programmed death ligand 1 immunotherapy by inducing immunogenic cell death in triple-negative breast cancer

BACKGROUND

Triple-negative breast cancer (TNBC), characterized by high heterogeneity and invasiveness. Currently, inducing immunogenic cell death (ICD) of tumor cells through approaches such as radiotherapy and chemotherapy is an effective strategy to enhance the response to anti-programmed death-ligand 1 antibody (aPD-L1) therapy in TNBC. However, radiotherapy and chemotherapy treatments often upregulate PD-L1 expression in tumor cells, thereby weakening the tumor cells' response to aPD-L1. Celastrol exhibits broad-spectrum and potent anti-tumor activity, efficiently inducing ICD without increasing PD-L1 levels in tumor cells.

PURPOSE

This study aims to elucidate the tumor-targeting effects of celastrol-loaded liposomes and its synergistic efficacy and mechanism of action in combination with aPD-L1 against TNBC.

METHODS

The Rg3 liposomes loaded with celastrol (Cel-Rg3-Lp) were prepared using the thin-film hydration method. BALB/c mice were utilized to establish an in situ breast cancer model. Mice were intravenously injected with Cel-Rg3-Lp at a dosage of celastrol 1 mg/kg once every two days for a total of 7 injections. Flow cytometry, western blot, and immunofluorescence techniques were employed to investigate the synergistic effects and mechanisms of Cel-Rg3-Lp combined with aPD-L1 in the treatment of TNBC.

RESULTS

The findings of this study demonstrate that after 7 administrations of Cel-Rg3-Lp (1 mg/kg celastrol, intravenously), significant anti-tumor effects are observed, including the recruitment of CD8+T cells and dendritic cells (DCs), while reducing the infiltration of immunosuppressive cells. The therapeutic efficacy was further enhanced when combined with aPD-L1. Additionally, Cel-Rg3-Lp markedly downregulated glucose-regulated protein 78 (GRP78) expression, thereby inducing ICD in tumor cells.

CONCLUSION

This study successfully constructed a multifunctional liposome and proposed a mechanism for inducing ICD through the GRP78-endoplasmic reticulum stress pathway. The liposome downregulates GRP78, triggering endoplasmic reticulum stress in tumor cells, inducing ICD, activating DCs, and enhancing antigen presentation to T cells. This improves the tumor immune microenvironment and provides a theoretical foundation for combining Cel-Rg3-Lp with aPD-L1 in the treatment of TNBC. This mechanism opens unique prospects for using celastrol in TNBC therapy and enhancing the effectiveness of immunotherapy.

The multiple functions and mechanisms of long non-coding RNAs in regulating breast cancer progression

Breast cancer (BC) is a malignant tumor that has the highest morbidity and mortality rates in the female population, and its high tendency to metastasize is the main cause of poor clinical prognosis. Long non-coding RNAs (lncRNAs) have been extensively documented to exhibit aberrant expression in various cancers and influence tumor progression via multiple molecular pathways. These lncRNAs not only modulate numerous aspects of gene expression in cancer cells, such as transcription, translation, and post-translational modifications, but also play a crucial role in the reprogramming of energy metabolism by regulating metabolic regulators, which is particularly significant in advanced BC. This review examines the characteristics and mechanisms of lncRNAs in regulating BC cells, both intracellularly (e.g., cell cycle, autophagy) and extracellularly (e.g., tumor microenvironment). Furthermore, we explore the potential of specific lncRNAs and their regulatory factors as molecular markers and therapeutic targets. Lastly, we summarize the application of lncRNAs in the treatment of advanced BC, aiming to offer novel personalized therapeutic options for patients.

Antitumor Research Based on Drug Delivery Carriers: Reversing the Polarization of Tumor-Associated Macrophages

The development of malignant tumors is a complex process that involves the tumor microenvironment (TME). An immunosuppressive TME presents significant challenges to current cancer therapies, serving as a key mechanism through which tumor cells evade immune detection and play a crucial role in tumor progression and metastasis. This impedes the optimal effectiveness of immunotherapeutic approaches, including cytokines, immune checkpoint inhibitors, and cancer vaccines. Tumor-associated macrophages (TAMs), a major component of tumor-infiltrating immune cells, exhibit dual functionalities: M1-like TAMs suppress tumorigenesis, while M2-like TAMs promote tumor growth and metastasis. Consequently, the development of various nanocarriers aimed at polarizing M2-like TAMs to M1-like phenotypes through distinct mechanisms has emerged as a promising therapeutic strategy to inhibit tumor immune escape and enhance antitumor responses. This Review covers the origin and types of TAMs, common pathways regulating macrophage polarization, the role of TAMs in tumor progression, and therapeutic strategies targeting TAMs, aiming to provide a comprehensive understanding and guidance for future research and clinical applications.

Ultrasound nanodroplets loaded with Siglec-G siRNA and Fe3O4 activate macrophages and enhance phagocytosis for immunotherapy of triple-negative breast cancer

BACKGROUND

The progression of triple-negative breast cancer is shaped by both tumor cells and the surrounding tumor microenvironment (TME). Within the TME, tumor-associated macrophages (TAMs) represent a significant cell population and have emerged as a primary target for cancer therapy. As antigen-presenting cells within the innate immune system, macrophages are pivotal in tumor immunotherapy through their phagocytic functions. Due to the highly dynamic and heterogeneous nature of TAMs, re-polarizing them to the anti-tumor M1 phenotype can amplify anti-tumor effects and help mitigate the immunosuppressive TME.

RESULTS

In this study, we designed and constructed an ultrasound-responsive targeted nanodrug delivery system to deliver Siglec-G siRNA and Fe3O4, with perfluorohexane (PFH) at the core and mannose modified on the surface (referred to as MPFS@NDs). Siglec-G siRNA blocks the CD24/Siglec-G mediated "don't eat me" phagocytosis inhibition pathway, activating macrophages, enhancing their phagocytic function, and improving antigen presentation, subsequently triggering anti-tumor immune responses. Fe3O4 repolarizes M2-TAMs to the anti-tumor M1 phenotype. Together, these components synergistically alleviate the immunosuppressive TME, and promote T cell activation, proliferation, and recruitment to tumor tissues, effectively inhibiting the growth of primary tumors and lung metastasis.

CONCLUSION

This work suggests that activating macrophages and enhancing phagocytosis to remodel the TME could be an effective strategy for macrophage-based triple-negative breast cancer immunotherapy.

Bilirubin-Modified Chondroitin Sulfate-Mediated Multifunctional Liposomes Ameliorate Acute Kidney Injury by Inducing Mitophagy and Regulating Macrophage Polarization

Acute kidney injury (AKI) is a dynamic process associated with inflammation, oxidative stress, and lipid peroxidation, in which mitochondrial mitophagy and macrophage polarization play a critical role in the pathophysiology. Based on the expression of the CD44 receptor on renal tubular epithelial cells (RTECs) and activated M1 macrophages being abnormally increased, accompanied by up-regulation of reactive oxygen species (ROS) during AKI, the conjugates of bilirubin (BR), an endogenous antioxidant which has the property of anti-inflammation, and chondroitin sulfate (CS) with CD44-targeting property could be a promising therapeutic carrier. In this study, we develop a CD44-targeted/ROS-responsive CS-BR-mediated multifunctional liposome loading celastrol (CS-BR@CLT) for the targeted therapy of AKI. CS-BR@CLT is shown to selectively accumulate in AKI mouse kidneys via targeting of CD44 receptors. Treatment with CS-BR@CLT significantly ameliorates acute kidney injury caused by ischemia-reperfusion and protects renal function. Mechanistically, CS-BR@CLT inhibits apoptosis, protects mitochondria, promotes autophagy, regulates macrophage polarization, and alleviates interstitial inflammation. Overall, our study demonstrates that CS-BR@CLT could be a promising strategy to ameliorate acute kidney injury.

Unravelling CD24-Siglec-10 pathway: Cancer immunotherapy from basic science to clinical studies

Cancer immunotherapy has revolutionized the treatment landscape by harnessing the power of the immune system to combat malignancies. Two of the most promising players in this field are cluster of differentiation 24 (CD24) and sialic acid-binding Ig-like lectin 10 (Siglec-10), and both of them play pivotal roles in modulating immune responses. CD24, a cell surface glycoprotein, emerges as a convincing fundamental signal transducer for therapeutic intervention, given its significant implication in the processes related to tumour progression and immunogenic evasion. Additionally, the immunomodulatory functions of Siglec-10, a prominent member within the Siglec family of immune receptors, have recently become a crucial point of interest, particularly in the context of the tumour microenvironment. Hence, the intricate interplay of both CD24 and Siglec-10 assumes a critical role in fostering tumour growth, facilitating metastasis and also orchestrating immune evasion. Recent studies have found multiple evidences supporting the therapeutic potential of targeting CD24 in cancer treatment. Siglec-10, on the other hand, exhibits immunosuppressive properties that contribute to immune tolerance within the tumour microenvironment. Therefore, we delve into the complex mechanisms through which Siglec-10 modulates immune responses and facilitates immune escape in cancer. Siglec-10 also acts as a viable target for cancer immunotherapy and presents novel avenues for the development of therapeutic interventions. Furthermore, we examine the synergy between CD24 and Siglec-10 in shaping the immunosuppressive tumour microenvironment and discuss the implications for combination therapies. Therefore, understanding the roles of CD24 and Siglec-10 in cancer immunotherapy opens exciting possibilities for the development of novel therapeutics.

Engineering macrophage membrane-camouflaged nanoplatforms with enhanced macrophage function for mediating sonodynamic therapy of ovarian cancer

Cancer immunotherapy has demonstrated remarkable efficacy in the treatment of cancer, and it has been successfully applied in the treatment of various solid tumors. However, the response rates to immunotherapy in patients with ovarian cancer remain modest because of the immunosuppressive tumor microenvironment (TME). Tumor-associated macrophages (TAMs) represent the predominant myeloid cell population within the TME, which adopt the protumorigenic M2 phenotype and are blinded by the "don't eat me" signals from tumor cells. These characteristics of TAMs result in insufficient phagocytic activation. In this study, we constructed a SIM@TR-NP-mediated combination therapy of sonodynamic and immunotherapy. SIM@TR-NPs were modified by engineered macrophage membranes with overexpressed sialic acid-binding Ig-like lectin 10 (Siglec-10), and were internally loaded with sonosensitizer 4,4',4'',4'''-(porphine-5,10,15,20-tetrayl)tetrakis(benzoic acid) and immune adjuvant resiquimod. SIM@TR-NPs can block "don't eat me" signals to enhance macrophage phagocytosis and trigger the polarization of TAMs toward the M1 phenotype, thereby improving the immunosuppressive TME. Simultaneously, upon ultrasound irradiation, SIM@TR-NP-mediated sonodynamic therapy (SDT) triggered immunogenic cell death in tumor cells, in combination with TAM-based immunotherapy, transforming the "immune cold tumor" into an "immune hot tumor". SIM@TR-NP-mediated sonodynamic immunotherapy exhibited potent antitumor efficacy in ovarian cancer and exhibited substantial potential for improving the immunosuppressive TME. This study presents an emerging therapeutic regimen for ovarian cancer that synergizes TAM-based antitumor immunotherapy and SDT.

Comprehensive review of drug-mediated ICD inhibition of breast cancer: mechanism, status, and prospects

The escalating incidence of breast cancer (BC) in women underscores its grave health threat. Current molecular insights into BC's post-adjuvant therapy cure remain elusive, necessitating active treatment explorations. Immunotherapy, notably chemotherapy-induced immunogenic cell death (ICD), has emerged as a promising BC therapy. ICD harnesses chemotherapeutics to activate anti-tumor immunity via DAMPs, fostering long-term T-cell memory and primary BC cure. Besides chemotherapy drugs, Nanodrugs, traditional Chinese medicine (TCM) and ICIs also induce ICD, boosting immune response. ICIs, like PD-1/PD-L1 inhibitors, revolutionize cancer treatment but face limited success in cold tumors. Thus, ICD induction combined with ICIs is studied extensively for BC immunotherapy. This article reviews the mechanism of ICD related drugs in BC and provides reference for the research and development of BC treatment, in order to explore more effective clinical treatment of BC, we hope to explore more ICD inducers and make ICIs more effective vaccines.

Modulating macrophage-mediated programmed cell removal: An attractive strategy for cancer therapy

Macrophage-mediated programmed cell removal (PrCR) is crucial for the identification and elimination of needless cells that maintain tissue homeostasis. The efficacy of PrCR depends on the balance between pro-phagocytic "eat me" signals and anti-phagocytic "don't eat me" signals. Recently, a growing number of studies have shown that tumourigenesis and progression are closely associated with PrCR. In the tumour microenvironment, PrCR activated by the "eat me" signal is counterbalanced by the "don't eat me" signal of CD47/SIRPα, resulting in tumour immune escape. Therefore, targeting exciting "eat me" signalling while simultaneously suppressing "don't eat me" signalling and eventually inducing macrophages to produce effective PrCR will be a very attractive antitumour strategy. Here, we comprehensively review the functions of PrCR-activating signal molecules (CRT, PS, Annexin1, SLAMF7) and PrCR-inhibiting signal molecules (CD47/SIRPα, MHC-I/LILRB1, CD24/Siglec-10, SLAMF3, SLAMF4, PD-1/PD-L1, CD31, GD2, VCAM1), the interactions between these molecules, and Warburg effect. In addition, we highlight the molecular regulatory mechanisms that affect immune system function by exciting or suppressing PrCR. Finally, we review the research advances in tumour therapy by activating PrCR and discuss the challenges and potential solutions to smooth the way for tumour treatment strategies that target PrCR.

Natural products with anti-tumorigenesis potential targeting macrophage

BACKGROUND

Inflammation is a risk factor for tumorigenesis. Macrophage, a subset of immune cells with high plasticity, plays a multifaceted role in this process. Natural products, which are bioactive compounds derived from traditional herbs or foods, have exhibited diverse effects on macrophages and tumorigenesis making them a valuable resource of drug discovery or optimization in tumor prevention.

PURPOSE

Provide a comprehensive overview of the various roles of macrophages in tumorigenesis, as well as the effects of natural products on tumorigenesis by modulating macrophage function.

METHODS

A thorough literature search spanning the past two decades was carried out using PubMed, Web of Science, Elsevier, and CNKI following the PRISMA guidelines. The search terms employed included "macrophage and tumorigenesis", "natural products, macrophages and tumorigenesis", "traditional Chinese medicine and tumorigenesis", "natural products and macrophage polarization", "macrophage and tumor related microenvironment", "macrophage and tumor signal pathway", "toxicity of natural products" and combinations thereof. Furthermore, certain articles are identified through the tracking of citations from other publications or by accessing the websites of relevant journals. Studies that meet the following criteria are excluded: (1) Articles not written in English or Chinese; (2) Full texts were not available; (3) Duplicate articles and irrelevant studies. The data collected was organized and summarized based on molecular mechanisms or compound structure.

RESULTS

This review elucidates the multifaceted effect of macrophages on tumorigenesis, encompassing process such as inflammation, angiogenesis, and tumor cell invasion by regulating metabolism, non-coding RNA, signal transduction and intercellular crosstalk. Natural products, including vitexin, ovatodiolide, ligustilide, and emodin, as well as herbal remedies, have demonstrated efficacy in modulating macrophage function, thereby attenuating tumorigenesis. These interventions mainly focus on mitigating the initial inflammatory response or modifying the inflammatory environment within the precancerous niche.

CONCLUSIONS

These mechanistic insights of macrophages in tumorigenesis offer valuable ideas for researchers. The identified natural products facilitate the selection of promising candidates for future cancer drug development.

Endoplasmic reticulum-targeted delivery of celastrol and PD-L1 siRNA for reinforcing immunogenic cell death and potentiating cancer immunotherapy

The prospect of employing chemoimmunotherapy targeted towards the endoplasmic reticulum (ER) presents an opportunity to amplify the synergistic effects of chemotherapy and immunotherapy. In this study, we initially validated celastrol (CEL) as an inducer of immunogenic cell death (ICD) by promoting ER stress and autophagy in colorectal cancer (CRC) cells. Subsequently, an ER-targeted strategy was posited, involving the codelivery of CEL with PD-L1 small interfering RNAs (siRNA) using KDEL peptide-modified exosomes derived from milk (KME), to enhance chemoimmunotherapy outcomes. Our findings demonstrate the efficient transportation of KME to the ER via the Golgi-to-ER pathway. Compared to their non-targeting counterparts, KME exhibited a significant augmentation of the CEL-induced ICD effect. Additionally, it facilitated the release of danger signaling molecules (DAMPs), thereby stimulating the antigen-presenting function of dendritic cells and promoting the infiltration of T cells into the tumor. Concurrently, the ER-targeted delivery of PD-L1 siRNA resulted in the downregulation of both intracellular and membrane PD-L1 protein expression, consequently fostering the proliferation and activity of CD8+ T cells. Ultimately, the ER-targeted formulation exhibited enhanced anti-tumor efficacy and provoked anti-tumor immune responses against orthotopic colorectal tumors in vivo. Collectively, a robust ER-targeted delivery strategy provides an encouraging approach for achieving potent cancer chemoimmunotherapy.

Nanoparticle-Mediated Immunotherapy in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is an aggressive subtype with the worst prognosis and highest recurrence rates. The treatment choices are limited due to the scarcity of endocrine and HER2 targets, except for chemotherapy. However, the side effects of chemotherapy restrict its long-term usage. Immunotherapy shows potential as a promising therapeutic strategy, such as inducing immunogenic cell death, immune checkpoint therapy, and immune adjuvant therapy. Nanotechnology offers unique advantages in the field of immunotherapy, such as improved delivery and targeted release of immunotherapeutic agents and enhanced bioavailability of immunomodulators. As well as the potential for combination therapy synergistically enhanced by nanocarriers. Nanoparticles-based combined application of multiple immunotherapies is designed to take the tactics of enhancing immunogenicity and reversing immunosuppression. Moreover, the increasing abundance of biomedical materials holds more promise for the development of this field. This review summarizes the advances in the field of nanoparticle-mediated immunotherapy in terms of both immune strategies for treatment and the development of biomaterials and presents challenges and hopes for the future.

Engineering nanomedicines for immunogenic eradication of cancer cells: Recent trends and synergistic approaches

Resistance to cancer immunotherapy is mainly attributed to poor tumor immunogenicity as well as the immunosuppressive tumor microenvironment (TME) leading to failure of immune response. Numerous therapeutic strategies including chemotherapy, radiotherapy, photodynamic, photothermal, magnetic, chemodynamic, sonodynamic and oncolytic therapy, have been developed to induce immunogenic cell death (ICD) of cancer cells and thereby elicit immunogenicity and boost the antitumor immune response. However, many challenges hamper the clinical application of ICD inducers resulting in modest immunogenic response. Here, we outline the current state of using nanomedicines for boosting ICD of cancer cells. Moreover, synergistic approaches used in combination with ICD inducing nanomedicines for remodeling the TME via targeting immune checkpoints, phagocytosis, macrophage polarization, tumor hypoxia, autophagy and stromal modulation to enhance immunogenicity of dying cancer cells were analyzed. We further highlight the emerging trends of using nanomaterials for triggering amplified ICD-mediated antitumor immune responses. Endoplasmic reticulum localized ICD, focused ultrasound hyperthermia, cell membrane camouflaged nanomedicines, amplified reactive oxygen species (ROS) generation, metallo-immunotherapy, ion modulators and engineered bacteria are among the most innovative approaches. Various challenges, merits and demerits of ICD inducer nanomedicines were also discussed with shedding light on the future role of this technology in improving the outcomes of cancer immunotherapy.

Targeting the GPI transamidase subunit GPAA1 abrogates the CD24 immune checkpoint in ovarian cancer

CD24 is frequently overexpressed in ovarian cancer and promotes immune evasion by interacting with its receptor Siglec10, present on tumor-associated macrophages, providing a "don't eat me" signal that prevents targeting and phagocytosis by macrophages. Factors promoting CD24 expression could represent novel immunotherapeutic targets for ovarian cancer. Here, using a genome-wide CRISPR knockout screen, we identify GPAA1 (glycosylphosphatidylinositol anchor attachment 1), a factor that catalyzes the attachment of a glycosylphosphatidylinositol (GPI) lipid anchor to substrate proteins, as a positive regulator of CD24 cell surface expression. Genetic ablation of GPAA1 abolishes CD24 cell surface expression, enhances macrophage-mediated phagocytosis, and inhibits ovarian tumor growth in mice. GPAA1 shares structural similarities with aminopeptidases. Consequently, we show that bestatin, a clinically advanced aminopeptidase inhibitor, binds to GPAA1 and blocks GPI attachment, resulting in reduced CD24 cell surface expression, increased macrophage-mediated phagocytosis, and suppressed growth of ovarian tumors. Our study highlights the potential of targeting GPAA1 as an immunotherapeutic approach for CD24+ ovarian cancers.

Nanomedicines as enhancers of tumor immunogenicity to augment cancer immunotherapy

The potential of cancer immunotherapy is hampered by the poor immunogenicity of cancer cells. Strategies to enhance tumor immunogenicity are imperative to enhance T cell-mediated anti-tumor immunity. Although conventional therapeutics can increase tumor antigen expression or stimulate the release of danger signals to promote immunogenic cell death (ICD), they face challenges relating to efficacy and tumor-specific delivery. Nanomedicines can efficiently deliver tumor antigens, immune adjuvants, epigenetic modulators, or ICD inducers through targeted drug delivery with minimal off-target effects. Collectively, nanomedicines can overcome biological barriers to immunotherapy through targeted antigen delivery, induction of ICD, or epigenetic remodeling, resulting in increased tumor immunogenicity.

Checkpoint CD24 function on tumor and immunotherapy

CD24 is a protein found on the surface of cells that plays a crucial role in the proliferation, invasion, and spread of cancer cells. It adheres to cell membranes through glycosylphosphatidylinositol (GPI) and is associated with the prognosis and survival rate of cancer patients. CD24 interacts with the inhibitory receptor Siglec-10 that is present on immune cells like natural killer cells and macrophages, leading to the inhibition of natural killer cell cytotoxicity and macrophage-mediated phagocytosis. This interaction helps tumor cells escape immune detection and attack. Although the use of CD24 as a immune checkpoint receptor target for cancer immunotherapy is still in its early stages, clinical trials have shown promising results. Monoclonal antibodies targeting CD24 have been found to be well-tolerated and safe. Other preclinical studies are exploring the use of chimeric antigen receptor (CAR) T cells, antibody-drug conjugates, and gene therapy to target CD24 and enhance the immune response against tumors. In summary, this review focuses on the role of CD24 in the immune system and provides evidence for CD24 as a promising immune checkpoint for cancer immunotherapy.

Targeting CD24/Siglec-10 signal pathway for cancer immunotherapy: recent advances and future directions

The small, heavily glycosylated protein CD24 is primarily expressed by many immune cells and is highly expressed mostly in cancer cells. As one of the most crucial biomarkers of cancers, CD24 is frequently highly expressed in solid tumors, while tumor-associated macrophages express Siglec-10 at high levels, Siglec-10 and CD24 can interact on innate immune cells to lessen inflammatory responses to a variety of disorders. Inhibiting inflammation brought on by SHP-1 and/or SHP-2 phosphatases as well as cell phagocytosis by macrophages, the binding of CD24 to Siglec-10 can prevent toll-like receptor-mediated inflammation. Targeted immunotherapy with immune checkpoint inhibitors (ICI) has lately gained popularity as one of the best ways to treat different tumors. CD24 is a prominent innate immune checkpoint that may be a useful target for cancer immunotherapy. In recent years, numerous CD24/Siglec-10-related research studies have made tremendous progress. This study discusses the characteristics and workings of CD24/Siglec-10-targeted immunotherapy and offers a summary of current advances in CD24/Siglec-10-related immunotherapy research for cancer. We then suggested potential directions for CD24-targeted immunotherapy, basing our speculation mostly on the results of recent preclinical and clinical trials.

Amplifying "eat me signal" by immunogenic cell death for potentiating cancer immunotherapy

Immunogenic cell death (ICD) is a unique mode of cell death, which can release immunogenic damage-associated molecular patterns (DAMPs) and tumor-associated antigens to trigger long-term protective antitumor immune responses. Thus, amplifying "eat me signal" during tumor ICD cascade is critical for cancer immunotherapy. Some therapies (radiotherapy, photodynamic therapy (PDT), photothermal therapy (PTT), etc.) and inducers (chemotherapeutic agents, etc.) have enabled to initiate and/or facilitate ICD and activate antitumor immune responses. Recently, nanostructure-based drug delivery systems have been synthesized for inducing ICD through combining treatment of chemotherapeutic agents, photosensitizers for PDT, photothermal transformation agents for PTT, radiosensitizers for radiotherapy, etc., which can release loaded agents at an appropriate dosage in the designated place at the appropriate time, contributing to higher efficiency and lower toxicity. Also, immunotherapeutic agents in combination with nanostructure-based drug delivery systems can produce synergetic antitumor effects, thus potentiating immunotherapy. Overall, our review outlines the emerging ICD inducers, and nanostructure drug delivery systems loading diverse agents to evoke ICD through chemoradiotherapy, PDT, and PTT or combining immunotherapeutic agents. Moreover, we discuss the prospects and challenges of harnessing ICD induction-based immunotherapy, and highlight the significance of multidisciplinary and interprofessional collaboration to promote the optimal translation of this treatment strategy.

IMM47, a humanized monoclonal antibody that targets CD24, exhibits exceptional anti-tumor efficacy by blocking the CD24/Siglec-10 interaction and can be used as monotherapy or in combination with anti-PD1 antibodies for cancer immunotherapy

This study evaluates the anti-tumor mechanism of IMM47, a humanized anti-CD24 mAb. Biolayer interferometry, ELISA and flow cytometry methods were used to measure the IMM47 binding, affinity, ADCC, ADCP, ADCT and CDC activities. In vivo therapeutical efficacy was measured in transplanted mouse models. IMM47 significantly binds granulocytes but not human erythrocytes and blocks CD24's ability to bind to Siglec-10. IMM47 has strong ADCC, ADCT and ADCP activity against REH cells. IMM47's in vivo pharmacodynamics showed that IMM47 has strong anti-tumor effects in human siglec-10 transgenic mouse models with a memory immune response. IMM47 also has powerful synergistic therapeutic efficacy when combined with Tislelizumab, Opdivo and Keytruda, by blocking CD24/Siglec-10 interaction through macrophage antigen presentation with strong ADCC, ADCP, ADCT and CDC activities and with a safe profile. IMM47 binding to CD24 is independent of N-glycosylation modification of the extracellular domain.

CD24 blockade as a novel strategy for cancer treatment

The CD24 protein is a heat-stable protein with a small core that undergoes extensive glycosylation. It is expressed on the surface of various normal cells, including lymphocytes, epithelial cells, and inflammatory cells. CD24 exerts its function by binding to different ligands. Numerous studies have demonstrated the close association of CD24 with tumor occurrence and progression. CD24 not only facilitates tumor cell proliferation, metastasis, and immune evasion but also plays a role in tumor initiation, thus, serving as a marker on the surface of cancer stem cells (CSCs). Additionally, CD24 induces drug resistance in various tumor cells following chemotherapy. To counteract the tumor-promoting effects of CD24, several treatment strategies targeting CD24 have been explored, such as the use of CD24 monoclonal antibodies (mAb) alone, the combination of CD24 and chemotoxic drugs, or the combination of these drugs with other targeted immunotherapeutic techniques. Regardless of the approach, targeting CD24 has demonstrated significant anti-tumor effects. Therefore, the present study focuses on anti-tumor therapy and provides a comprehensive review of the structure and fundamental physiological function of CD24 and its impact on tumor development, and suggests that targeting CD24 may represent an effective strategy for treating malignant tumors.