Redefining Tumor-Associated Macrophage Subpopulations and Functions in the Tumor Microenvironment

A machine learning approach to risk-stratification of gastric cancer based on tumour-infiltrating immune cell profiles

BACKGROUND

Gastric cancer (GC) is a highly heterogeneous disease, and the response of patients to clinical treatment varies substantially. There is no satisfactory strategy for predicting curative effects to date. We aimed to explore a new method for predicting the clinical efficacy of GC treatment based on immune variables detected via flow cytometry.

METHODS

We collected 394 tumour tissues from GC patients for flow cytometry analysis and gating analysis of tumour-infiltrating immune cells (TIICs). Unsupervised consensus clusters were generated from the cohort to classify patients into different phenogroups, and their clinical characteristics were examined. The derived model was evaluated via principal component analysis and t-distributed stochastic neighbourhood embedding analysis. Kaplan-Meier's curves were used to determine the prognosis during a 920-day-long median follow-up period (interquartile range: 834-1071 days). Adjusted multivariate Cox regression analysis was used to evaluate the association of clusters with disease-free survival (DFS) and recurrence.

RESULTS

All patients were classified based on their TIIC profiles into the C1 (characterized by low CD45 negative cell, high lymphocyte, high neutrophil and low CD3 + T cell levels), C2 (characterized by high CD8 + CD279+ cell and low CD4+ Th and CD8+ Tc cell numbers) and C3 (characterized by high CD4 + CD25+ and Treg cell levels) phenogroups. Patients from the three clusters had varied pathologies, MMR statuses and TIIC distribution patterns (p < .05). Kaplan-Meier's analysis showed that the prognosis of C3 was inferior compared to C1 and C2 (p = .0025). Adjusted Cox proportional hazard models helped us identify that C1 and C2 exhibited a favourable factor of recurrence after surgery, compared to C3. Kaplan-Meier's analysis showed that C1 and C2 were associated with a better DFS than C3 in some GC patient subgroups.

CONCLUSIONS

The machine learning model developed was found to be effective model at predicting the prognosis of patients with GC and their TIIC profiles for risk stratification in clinical settings.

IDO1-mediated M2 macrophage polarization alleviates the progression of ankylosing spondylitis

Indoleamine 2,3-dioxygenase 1 (IDO1) plays an anti-inflammatory role in autoimmune disease. However, its specific function in ankylosing spondylitis (AS) remain unclear. This study aimed to investigate the potential role of IDO1 in AS. Immunofluorescence, RT-qPCR, and western blot assays were employed to measure gene expression, while ELISA was used to quantify the release of M1 macrophage and M2 macrophage markers. CCK-8, EdU, flow cytometry, ALP staining, and Alizarin red staining (ARS) assays were conducted for functional analysis. JASPAR predicted the binding sites between PPARγ and the promoter, which were further validated by luciferase and ChIP assays. Our findings revealed that the expression of IDO1 was markedly elevated in AS patients. IDO1 overexpression promoted the proliferation of THP-1 cells and M2 macrophage polarization. Conversely, IDO1 knockdown facilitated the osteogenic differentiation of BMSCs. Furthermore, IDO1-mediated upregulation of PPARγ modulated RUNX2 transcription. PPARγ overexpression counteracted the effects of IDO1 knockdown, thereby inhibiting the osteogenic differentiation of BMSCs. In conclusion, the IDO1/PPARγ/RUNX2 signaling pathway may protect against AS by promoting M2 macrophage polarization and inhibiting osteogenic differentiation.

Dynamics of inflammatory signals within the tumor microenvironment

Tumor stroma, or tumor microenvironment (TME), has been in the spotlight during recent years for its role in tumor development, growth, and metastasis. It consists of a myriad of elements, including tumor-associated macrophages, cancer-associated fibroblasts, a deregulated extracellular matrix, endothelial cells, and vascular vessels. The release of proinflammatory molecules, due to the inflamed microenvironment, such as cytokines and chemokines is found to play a pivotal role in progression of cancer and response to therapy. This review discusses the major key players and important chemical inflammatory signals released in the TME. Furthermore, the latest breakthroughs in cytokine-mediated crosstalk between immune cells and cancer cells have been highlighted. In addition, recent updates on alterations in cytokine signaling between chronic inflammation and malignant TME have also been reviewed.

The crosstalk between lung adenocarcinoma cells and M2 macrophages promotes cancer cell development via the SFRS1/miR-708-5p/PD-L1 axis

This study aimed to elucidate the underlying mechanisms regarding microRNA-708-5p (miR-708-5p) in lung adenocarcinoma (LUAD). Here, the co-culture system of LUAD cells and macrophages, as well as a xenograft mouse model, were established. High levels of miR-708-5p were observed in LUAD. Exosomal miR-708-5p facilitated M2-like phenotype polarization, whereas miR-708-5p inhibition blocked the polarization. Exosomal miR-708-5p was identified as a pivotal signaling molecule for macrophages to mediate tumor cell proliferation, invasion, migration and IFN-γ production in T cells. In addition, miR708-5p was observed to induce PD-L1 expression, and PD-L1 silencing inhibited macrophage-induced tumor cell growth behavior and regulated CD8 T cell activity. In xenograft models, miR-708-5p inhibition and PD-L1 silencing attenuated macrophage-induced tumor growth, induced IFN-γ secretion and CD8 expression, and modulated the PTEN/AKT/mTOR pathway. In LUAD patients, there was an upregulation of both miR-708-5p and PD-L1 expression, accompanied by the activation of PTEN/AKT/mTOR. In conclusion, this study demonstrated the induction of M2 macrophage polarization and PD-L1 expression by exosomal miR-708-5p. We observed that exosomal miR-708-5p mediated the PTEN/AKT/mTOR pathway, diminished CD8 T cell activity and accelerated LUAD progression. The inhibition of specific exosomal miRNA secretion and anti-PD-L1 in the LUAD microenvironment may represent a promising avenue for LUAD immunotherapy.

Polysaccharides from traditional Chinese medicine and their nano-formulated delivery systems for cancer immunotherapy

Cancer immunotherapy has evolved into a new generation strategy in the field of anti-tumor treatment. Polysaccharides derived from Traditional Chinese Medicine (TCM) are gaining recognition as powerful immunomodulators in cancer therapy, noted for their multi-target and multi-pathway actions. Owing to their beneficial properties such as water solubility, biocompatibility, and chemical structure modifiability, TCM polysaccharides can also serve as carriers for hydrophobic drugs in the development of innovative drug delivery systems, enhancing synergistic antitumor effects. In this article, we summarize the diverse mechanisms of immunoregulation by TCM polysaccharides in tumor therapy. The applications of these polysaccharides as both active ingredients and drug carriers within nanodelivery systems for cancer immunotherapy are also introduced. Additionally, extensive research on TCM polysaccharides in clinical settings has been collected. Furthermore, discussions are presented on the development prospects and challenges faced by these polysaccharides in the field of tumor immunotherapy. Our goal is to improve researchers' comprehension of TCM polysaccharides in cancer immunotherapy, providing promising strategies to optimize cancer treatment and benefit diverse patient populations.

Immunoglobulin-like transcript 5 polarizes M2-like tumor-associated macrophages for immunosuppression in non-small cell lung cancer

Immune checkpoint inhibitors (ICIs) have shifted the treatment paradigm of non-small cell lung cancer (NSCLC) over the last decade. Despite notable therapeutic advancements in responders, the response rate remains limited owing to the immunosuppressive tumor microenvironment (TME). Therefore, to improve the efficacy of ICIs, it is essential to explore alternative targets or signals that mediate immunosuppression. Immunoglobulin-like transcript (ILT) 5 is a negative regulator of immune activation in myeloid cells. However, the expression and function of ILT5 in NSCLC remain unknown. Here, we found that ILT5 was highly expressed in tumor-associated macrophages (TAMs) of NSCLC tissues and predicted poor patient survival. Functionally, ILT5 induces the M2-like polarization of TAMs, which subsequently decreases the density of T cells, and increases FOXP3+T cell accumulation, leading to an immunosuppressive TME. The combination of ILT5 expression with M2-like TAM density is a more reliable biomarker of patient survival than ILT5 expression alone. ILT5 knockout mitigates the reprogramming of TAM and T cell subsets toward immunosuppressive phenotypes and inhibits tumor growth in vivo. These findings highlight that ILT5 is a potential immunotherapeutic target and a promising prognostic biomarker for NSCLC.

SPP1 + macrophages in colorectal cancer: Markers of malignancy and promising therapeutic targets

SPP1+ macrophages have been identified as key players in the colorectal cancer (CRC) tumor microenvironment, but their function remains unclear. This study integrated single-cell and spatial transcriptomics with bulk sequencing to investigate the roles and mechanisms of SPP1 + macrophages in CRC. Our findings revealed a pronounced elevation of SPP1 + macrophages in CRC, especially within tumor territories. These macrophages served as markers for CRC initiation, progression, metastasis, and potential prognosis. Furthermore, they showed heightened transcriptional activity in genes linked to angiogenesis, epithelial-mesenchymal transition, glycolysis, hypoxia, and immunosuppression. SPP1 protein amplified CRC cell migration and invasion, potentially mediating cellular crosstalk via the SPP1-CD44, SPP1-PTGER4, and SPP1-a4b1 complex axes. Patients with a high proportion of SPP1 + macrophages could benefit more from immune checkpoint blockade therapy. Interestingly, CSF1R expression was significantly enriched in C1QC + macrophages versus SPP1 + macrophages, possibly explaining limited anti-CSF1R monotherapy effects. In conclusion, we propose an SPP1 + macrophage model in CRC, highlighting such macrophages as a promising therapeutic target due to their malignancy markers.

Heterogeneity of the tumor immune cell microenvironment revealed by single-cell sequencing in head and neck cancer

Head and neck cancer (HNC) is the sixth most common disease in the world. The recurrence rate of patients is relatively high, and the heterogeneity of tumor immune microenvironment (TIME) cells may be an important reason for this. Single-cell sequencing (SCS) is currently the most promising and mature application in cancer research. It can identify unique genes expressed in cells and study tumor heterogeneity. According to current research, the heterogeneity of immune cells has become an important factor affecting the occurrence and development of HNC. SCSs can provide effective therapeutic targets and prognostic factors for HNC patients through analyses of gene expression levels and cell heterogeneity. Therefore, this study analyzes the basic theory of HNC and the development of SCS technology, elaborating on the application of SCS technology in HNC and its potential value in identifying HNC therapeutic targets and biomarkers.

Reprogramming and targeting of cholesterol metabolism in tumor-associated macrophages

Cholesterol, as a major component of cell membranes, is closely related to the metabolic regulation of cells and organisms; tumor-associated macrophages play an important push role in tumor progression. We know that tumor-associated macrophages are polarized from macrophages, and the abnormalities of cholesterol metabolism that may be induced during their polarization are worth discussing. This manuscript focuses on metabolic abnormalities in tumor-associated macrophages, and first provides a basic summary of the regulatory mechanisms of abnormal macrophage polarization. Subsequently, it comprehensively describes the features of abnormal glucose, lipid and cholesterol metabolism in TAMs as well as the different regulatory pathways. Then, the paper also discusses the link between abnormal cholesterol metabolism in TAMs and tumors, chronic diseases and aging. Finally, the paper summarizes cancer therapeutic strategies targeting cholesterol metabolism that are already in clinical trials, as well as nanomaterials capable of targeting cholesterol metabolism that are in the research stage, in the hope of providing value for the design of targeting materials. Overall, elucidating metabolic abnormalities in tumor-associated macrophages, particularly cholesterol metabolism, could provide assistance in tumor therapy and the design of targeted drugs.

Spatial transcriptomics reveals regionally altered gene expression that drives retinal degeneration

Photoreceptor cell death is a hallmark of age-related macular degeneration. Environmental, lifestyle and genetic risk factors are known contributors to disease progression, whilst at the molecular level, oxidative stress and inflammation are central pathogenetic drivers. However, the spatial and cellular origins of these molecular mechanisms remain unclear. We used spatial transcriptomics to investigate the spatio-temporal gene expression changes in the adult mouse retina in response to photo-oxidative stress. We identify regionally distinct transcriptomes, with higher expression of immunity related genes in the superior retina. Exposure to stress induced expression of genes involved in inflammatory processes, innate immune responses, and cytokine production in a highly localised manner. A distinct region ~800 µm superior from the optic nerve head seems a key driver of these molecular changes. Further, we show highly localised early molecular changes in the superior mouse retina during retinal stress and identify novel genes drivers. We provide evidence of angiogenic changes in response to photo-oxidative stress and suggest additional angiogenic signalling pathways within the retina including VEGF, pleiotrophin and midkine. These new insights into retinal angiogenesis pave the way to identify novel drivers of retinal neovascularisation with an opportunity for therapeutic development.

Nanomaterials-driven in situ vaccination: a novel frontier in tumor immunotherapy

In situ vaccination (ISV) has emerged as a promising strategy in cancer immunotherapy, offering a targeted approach that uses the tumor microenvironment (TME) to stimulate an immune response directly at the tumor site. This method minimizes systemic exposure while maintaining therapeutic efficacy and enhancing safety. Recent advances in nanotechnology have enabled new approaches to ISV by utilizing nanomaterials with unique properties, including enhanced permeability, retention, and controlled drug release. ISV employing nanomaterials can induce immunogenic cell death and reverse the immunosuppressive and hypoxic TME, thereby converting a "cold" tumor into a "hot" tumor and facilitating a more robust immune response. This review examines the mechanisms through which nanomaterials-based ISV enhances anti-tumor immunity, summarizes clinical applications of these strategies, and evaluates its capacity to serve as a neoadjuvant therapy for eliminating micrometastases in early-stage cancer patients. Challenges associated with the clinical translation of nanomaterials-based ISV, including nanomaterial metabolism, optimization of treatment protocols, and integration with other therapies such as radiotherapy, chemotherapy, and photothermal therapy, are also discussed. Advances in nanotechnology and immunotherapy continue to expand the possible applications of ISV, potentially leading to improved outcomes across a broad range of cancer types.

Crosstalk between exosomes and tumor-associated macrophages in hepatocellular carcinoma: implication for cancer progression and therapy

Hepatocellular carcinoma (HCC), the most prevalent type of primary liver cancer, represents a significant cause of cancer-related mortality. While our understanding of its pathogenesis is comparatively comprehensive, the influence of the tumor microenvironment (TME) on its progression warrants additional investigation. Tumor-associated macrophages (TAMs) have significant impacts on cancer cell proliferation, migration, invasion, and immune response, facilitating a complex interaction within the TME. Exosomes, which measure between 30 and 150 nanometers in size, are categorized into small extracellular vesicles, secreted by a wide range of eukaryotic cells. They can transfer biological molecules including proteins, non-coding RNAs, and lipids, which mediates the intercellular communication within the TME. Emerging evidence has revealed that exosomes regulate macrophage polarization, thus impacting cancer progression and immune responses within the TME of HCC. Moreover, TAM-derived exosomes also play crucial roles in malignant transformation, which hold immense potential for cancer therapy. In this review, we elaborate on the crosstalk between exosomes and TAMs within TME during HCC development. Moreover, we delve into the feasible treatment approaches for exosomes in cancer therapy and emphasize the limitations and challenges for the translation of exosomes derived from TAMs into clinical courses for cancer therapy, which may provide new perspectives on further ameliorations of therapeutic regimes based on exosomes to advance their clinical applications.

CaMKK2 Regulates Macrophage Polarization Induced by Matrix Stiffness: Implications for Shaping the Immune Response in Stiffened Tissues

Macrophages are essential for immune responses and maintaining tissue homeostasis, exhibiting a wide range of phenotypes depending on their microenvironment. The extracellular matrix (ECM) is a vital component that provides structural support and organization to tissues, with matrix stiffness acting as a key regulator of macrophage behavior. Using physiologically relevant 3D stiffening hydrogel models, it is found that increased matrix stiffness alone promoted macrophage polarization toward a pro-regenerative phenotype, mimicking the effect of interleukin-4(IL-4) in softer matrices. Blocking Calcium/calmodulin-dependent kinase kinase 2 (CaMKK2) selectively inhibited stiffness-induced macrophage polarization without affecting IL-4-driven pro-regenerative pathways. In functional studies, CaMKK2 deletion prevented M2-like/pro-tumoral polarization caused by matrix stiffening, which in turn hindered tumor growth. In a murine wound healing model, loss of CaMKK2 impaired matrix stiffness-mediated macrophage accumulation, ultimately disrupting vascularization. These findings highlight the critical role of CaMKK2 in the macrophage mechanosensitive fate determination and gene expression program, positioning this kinase as a promising therapeutic target to selectively modulate macrophage responses in pathologically stiff tissues.

MARMOT: A multifaceted R pipeline for analysing spectral flow cytometry data from subcutaneously growing murine gastric organoids

The analysis of murine immune cell types is a critical component of immunological research, necessitating precise and reproducible methodologies. Here, we present a comprehensive protocol and pipeline designed to streamline the process from murine gastric organoid transplant sample preparation to figure generation. This pipeline includes a detailed staining panel tailored for murine immune cells, ensuring accurate and comprehensive identification of various cell types. Additionally, it integrates an R-based analysis script (MARMOT Pipeline), encompassing data processing and visualisation. A key feature of this pipeline is its ability to produce publication-quality figures with minimal direct R coding, thus making advanced data analysis accessible to researchers with limited programming experience. Additionally, figures can be customised using a provided Shiny application. This approach both enhances the efficiency of data analysis and enables the reproducibility required for high-quality scientific research.

Characterizing macrophage diversity in colorectal malignancies through single-cell genomics

Colorectal cancer (CRC) is one of the most common malignant tumors of the digestive tract, with increasing incidence and mortality rates, posing a significant burden on human health. Its progression relies on various mechanisms, among which the tumor microenvironment and tumor-associated macrophages (TAMs) have garnered increasing attention. Macrophage infiltration in various solid tumors is associated with poor prognosis and is linked to chemotherapy resistance in many cancers. These significant biological behaviors depend on the heterogeneity of macrophages. Tumor-promoting TAMs comprise subpopulations characterized by distinct markers and unique transcriptional profiles, rendering them potential targets for anticancer therapies through either depletion or reprogramming from a pro-tumoral to an anti-tumoral state. Single-cell RNA sequencing technology has significantly enhanced our research resolution, breaking the traditional simplistic definitions of macrophage subtypes and deepening our understanding of the diversity within TAMs. However, a unified elucidation of the nomenclature and molecular characteristics associated with this diversity remains lacking. In this review, we assess the application of conventional macrophage polarization subtypes in colorectal malignancies and explore several unique subtypes defined from a single-cell omics perspective in recent years, categorizing them based on their potential functions.

Oropharyngeal carcinomas induce circulating monocytes to express a TAM-like pro-tumor expression profile that suppresses T-cell proliferation

Introduction

Tumor-associated macrophages (TAMs) recruited from circulating monocytes drive tumor-growth and establish an immunosuppressive tumor microenvironment (TME). Initial events in transition from resting monocytes to TAMs are poorly understood. Here, we report that monocytes from oropharyngeal cancer (OPC) patients and control monocytes treated with OPC-conditioned media (CM) express a repertoire of pro-tumor mediators that is characteristic of TAMs.

Methods

Monocytes were stimulated with OPC cell line CM, analyzed by single-cell RNAseq. Results of select genes were confirmed by qPCR with monocytes and analyzed in OPC tumors vs. clinically normal tissue. OPC spheroids containing control monocytes and T-cells were established, TAM phenotype characterized by flow analysis and qPCR, and T-cell proliferation assessed by flow.

Results

OPC-conditioned media induced multiple pro-tumor genes including CXCL1, CXCL5, CXCL8, SPP1, IL1B, GPNMB, and FABP5. Patient monocytes had higher baseline levels or achieved higher levels after stimulation than control monocytes. A subset of patient monocytes had high baseline levels of CXCL9/-10/-11 expression that resisted downregulation in response to stimulation, a potential sign of a more favorable TME. CXCL9/-10/-11 expression in OPC tumor biopsies compared to clinically normal tissue correlated with patient outcome. Spheroid TAMs derived from control monocytes maintained the pro-tumor repertoire seen with monocytes stimulated by tumor line conditioned media. These TAMs suppress T-cell proliferation. Inhibition of COX-2 or IL1 signaling during differentiation into TAMs partially blocked the suppression of T-cell proliferation.

Conclusion

Targeting the early transition of monocytes into pro-tumor TAMs could be used to develop new therapies for OPC.

Redefining hepatocellular carcinoma treatment: nanotechnology meets tumor immune microenvironment

Hepatocellular carcinoma (HCC) is one of the most lethal malignancies worldwide, characterised by its complex pathogenesis and poor therapeutic outcomes. Despite recent advances in targeted molecular therapies, immune checkpoint inhibitors (ICIs), radiotherapy and conventional chemotherapy, the 5-year survival rate for this neoplasm remains dismally low. The progress in nanotechnology has revolutionised cancer treatment in recent years. These advances provide unprecedented opportunities to overcome the current limitations of different therapeutic modalities. This review provides a comprehensive analysis of how nanotechnology interfaces with the tumour immune microenvironment (TIME) in HCC and can present a new frontier in therapeutic interventions for HCC. We critically overview the latest developments in nanoparticle-based delivery systems for various drugs and also other antitumor agents like thermal therapy and radiotherapy. We also highlight the unique ability of nanoparticles to modulate the immunosuppressive tumour microenvironment (TME) and enhance therapeutic efficacy. Furthermore, we analyse emerging strategies that exploit nanoformulations to overcome biological barriers and enhance drug bioavailability in HCC treatment.

Exosomal miR-92a-3p modulates M2 macrophage polarization in colorectal cancer: implications for tumor migration and angiogenesis

Colorectal cancer (CRC) is one of the most prevalent malignant neoplasms globally. Its development and metastasis are closely associated with the polarization of macrophages within the tumor microenvironment (TME). In particular, the polarization of M2-type macrophages has been demonstrated to be related to the promotion of tumor growth, migration, and angiogenesis. This study aims to investigate the role of miR-92a-3p in colon cancer-derived exosomes in regulating M2-type macrophage polarization by targeting EID2B and to elucidate the impact of this process on tumor migration and angiogenesis. MicroRNAs that were differentially expressed in plasma exosomes from CRC patients were initially identified through a search of the GEO database. The results were then verified by RT-qPCR using miR-92a-3p. The uptake of exosomes was observed via laser confocal microscopy, and the impact of miR-92a-3p on the polarization of exosomes and macrophages was examined through the use of RT-qPCR and WB. A bioinformatics analysis and a dual-luciferase reporter assay were employed to identify the downstream target of miR-92a-3p and to investigate its effect on the MAPK/ERK pathway. miR-92a-3p was upregulated in plasma exosomes of colon cancer patients and exhibited a positive correlation with lymph node metastasis. The results demonstrated that miR-92a-3p was capable of promoting M0 macrophage polarization toward the M2 phenotype, and of enhancing the migratory and invasive capacities of CRC cells, as well as their angiogenic potential in vitro. Bioinformatic analysis and experimental validation demonstrated that miR-92a-3p targeted EID2B and that this target gene was negatively correlated with M2-type macrophage polarization. The results demonstrated that miR-92a-3p promotes macrophage M2 polarization by activating the MAPK/ERK pathway. miR-92a-3p activates the MAPK/ERK pathway and induces macrophage M2 polarization by targeting EID2B, thereby promoting migration and angiogenesis in CRC. These findings offer new potential targets for the treatment of colon cancer.

Revolutionary Cancer Therapy for Personalization and Improved Efficacy: Strategies to Overcome Resistance to Immune Checkpoint Inhibitor Therapy

Cancer remains a significant public health issue worldwide, standing as a primary contributor to global mortality, accounting for approximately 10 million fatalities in 2020 [...].

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.

Multidimensional applications of prussian blue-based nanoparticles in cancer immunotherapy

Immunotherapy holds notable progress in the treatment of cancer. However, the clinical therapeutic effect remains a significant challenge due to immune-related side effects, poor immunogenicity, and immunosuppressive microenvironment. Nanoparticles have emerged as a revolutionary tool to surmount these obstacles and amplify the potency of immunotherapeutic agents. Prussian blue nanoparticles (PBNPs) exhibit multi-dimensional immune function in cancer immunotherapy, including acting as a nanocarrier to deliver immunotherapeutic agents, as a photothermal agent to improve the efficacy of immunotherapy through photothermal therapy, as a nanozyme to regulate tumor microenvironment, and as an iron donor to induce immune events related to ferroptosis and tumor-associated macrophages polarization. This review focuses on the advances and applications of PBNPs in cancer immunotherapy. First, the biomedical functions of PBNPs are introduced. Then, based on the immune function of PBNPs, we systematically reviewed the multidimensional application of PBNPs in cancer immunotherapy. Finally, the challenges and future developments of PBNPs-based cancer immunotherapy are highlighted.

CKIP-1 inhibits M2 macrophage polarization to suppress the progression of gastric cancer by inactivating JAK/STAT3 signaling

Gastric cancer (GC) is a frequently occurring malignancy with poor prognosis. Casein kinase 2 interacting protein-1 (CKIP-1) is a PH domain-containing protein implicated in regulating tumorigenesis and macrophage homeostasis. This study aimed to elucidate the role and potential mechanism of CKIP-1 in the progression of GC. CKIP-1 expression in GC tumor and para-carcinoma tissues was detected using RT-qPCR. Then, human monocyte cell line THP-1 was treated with PMA, interleukin (IL)-4 and IL-13 to induce M2-polarized macrophages. CD206, arginase-1 (Arg-1) and transforming growth factorβ1 (TGFβ1) expression in M2-polarized macrophages with or without CKIP-1 overexpression was evaluated. Moreover, GC cell lines (MKN45 and HGC27 cells) were co-cultured with CKIP-1-overexpressed M2-polarized macrophages, and the viability, migration and invasion of GC cells were measured. Additionally, immunoblotting assessed the expression of JAK/STAT3 signaling-related proteins and STAT3 agonist Colivelin was used to treat GC cells to perform the rescue experiments to analyze the changes of malignant phenotypes of GC cells. Results showed that CKIP-1 was downregulated in GC tissues and M2-polarized macrophages. CKIP-1 overexpression inhibited M2 macrophage polarization and decreased TGFβ1 secretion. Besides, elevated CKIP-1 expression in M2-polarized macrophages inhibited the viability, migration and invasion of GC cells. Furthermore, CKIP-1 overexpression inactivated JAK2/STAT3 signaling in GC cells by inhibiting TGFβ1 level. Specifically, Colivelin treatment abrogated the influences of CKIP-1 upregulation on the malignant phenotypes of GC cells. Collectively, CKIP-1 inhibits M2 macrophage polarization to suppress the progression of GC by inactivating JAK/STAT3 signaling pathway.

UBE2I depletion regulated tumor-associated macrophage polarization into M1 type through reprogramming glycolysis and increases immunotherapy efficacy of anti-PD-L1 in ovarian cancer

There is ample evidence that ubiquitin-conjugating enzyme E2I (UBE2I) is involved in progression of diverse cancers. However, the influence of UBE2I on ovarian cancer (OC) has been poorly reported. This study tries to discover the mechanisms and functions of UBE2I in OC. Relative mRNA expression of UBE2I, CD86, iNOS, MHC II and programmed death ligand 1 (PD-L1) was detected through qRT-PCR. We identified UBE2I, Vimentin, E-Cadherin, N-Cadherin and Ki67 protein expression levels in tumor tissues through immunohistochemistry staining. Protein levels of UBE2I, cleaved caspase-3, cleaved PARP, E-cadherin, N-cadherin and Vimentin were detected through western blot. Cell viability, invasion, and migration were examined by means of cell counting kit-8 (CCK-8), transwell, and wound healing assays. Immunofluorescence was used to detect colocalization between UBE2I and CD68. We assessed expression levels of IFN-γ and TNF-α via flow cytometry and ELISA. We used the TUNEL assay to assess tumor cell apoptosis. Glycolysis was assessed through the consumption of glucose, ATP production, production of lactate, and extracellular acidification rate. For establishing a xenograft model, OC cells were subcutaneously injected into mice. UBE2I expression was boosted in OC cells and tissues, which was negatively associated with OC patients' prognosis. Silencing of UBE2I suppressed OC cell proliferation, invasion, EMT (epithelial-to-mesenchymal transition) and migration. UBE2I inhibition promoted macrophages toward the M1 phenotype and macrophage viability. After deletion of UBE2I in vivo, mice tumor growth and EMT were suppressed, and apoptosis of tumor cells was increased. Meantime, an increasing proportion of CD86+ TAMs (tumor-associated macrophages) was observed after the deletion of UBE2I. Besides, increases in consumption of glucose, lactate production, ATP production and ECAR in THP-1 cells were observed by silencing of UBE2I; however, glycolysis inhibitor reversed UBE2I-mediated polarization of M1 macrophages in a dose-dependent fashion. Importantly, UBE2I-mediated M1 macrophages promoted PD-L1 expression. Furthermore, the combinatorial therapy of UBE2I inhibitor plus anti-PD-1 repressed tumor growth, reduced Ki67 expression, and promoted apoptosis in tumor cells, exhibiting higher efficiency than UBE2I inhibitor/anti-PD-L1 alone. UBE2I inhibition regulated polarization of M1 macrophages via glycolysis and improved anti-PD-L1 immunotherapy efficacy, paving a novel avenue to prevent OC development.

Utilizing Nanoparticles to Overcome Anti-PD-1/PD-L1 Immunotherapy Resistance in Non-Small Cell Lung cancer: A Potential Strategy

Lung cancer is the leading cause of cancer-related mortality globally, with non-small cell lung cancer (NSCLC) constituting 85% of cases. Immune checkpoint inhibitors (ICIs) represented by anti-programmed cell death protein 1 (PD-1)/ programmed cell death ligand 1 (PD-L1) have emerged as a promising frontier in cancer treatment, effectively extending the survival of patients with NSCLC. However, the efficacy of ICIs exhibits significant variability across diverse patient populations, with a substantial proportion showing poor responsiveness and acquired resistance in those initially responsive to ICIs treatments. With the advancement of nanotechnology, nanoparticles offer unique advantages in tumor immunotherapy, including high permeability and prolonged retention(EPR) effects, enhanced drug delivery and stability, and modulation of the inflammatory tumor microenvironment(TME). This review summarizes the mechanisms of resistance to ICIs in NSCLC, focusing on tumor antigens loss and defective antigen processing and presentation, failure T cell priming, impaired T cell migration and infiltration, immunosuppressive TME, and genetic mutations. Furthermore, we discuss how nanoparticles, through their intrinsic properties such as the EPR effect, active targeting effect, shielding effect, self-regulatory effect, and synergistic effect, can potentiate the efficacy of ICIs and reverse resistance. In conclusion, nanoparticles serve as a robust platform for ICIs-based NSCLC therapy, aiding in overcoming resistance challenges.

The role of macrophages in liver metastasis: mechanisms and therapeutic prospects

Metastasis is a hallmark of advanced cancer, and the liver is a common site for secondary metastasis of many tumor cells, including colorectal, pancreatic, gastric, and prostate cancers. Macrophages in the tumor microenvironment (TME) promote tumor cell metastasis through various mechanisms, including angiogenesis and immunosuppression, and play a unique role in the development of liver metastasis. Macrophages are affected by a variety of factors. Under conditions of hypoxia and increased acidity in the TME, more factors are now found to promote the polarization of macrophages to the M2 type, including exosomes and amino acids. M2-type macrophages promote tumor cell angiogenesis through a variety of mechanisms, including the secretion of factors such as VEGF, IL-1β, and TGF-β1. M2-type macrophages are subjected to multiple regulatory mechanisms. They also interact with various cells within the tumor microenvironment to co-regulate certain conditions, including the creation of an immunosuppressive microenvironment. This interaction promotes tumor cell metastasis, drug resistance, and immune escape. Based on the advent of single-cell sequencing technology, further insights into macrophage subpopulations in the tumor microenvironment may help in exploring new therapeutic targets in the future. In this paper, we will focus on how macrophages affect the TME, how tumor cells and macrophages as well as other immune cells interact with each other, and further investigate the mechanisms involved in liver metastasis of tumor cells and their potential as therapeutic targets.

Maraviroc enhances Bortezomib sensitivity in multiple myeloma by inhibiting M2 macrophage polarization via PI3K/AKT/RhoA signaling pathway in macrophages

BACKGROUND

Multiple myeloma (MM) is a malignancy where drug resistance often leads to relapse or refractory disease. Chemokine receptor 5 (CCR5) has emerged as a novel therapeutic target. However, the role of CCR5-antagonist Maraviroc (MVC) in M2 macrophage polarization and its potential to enhance Bortezomib sensitivity in MM has not been fully explored.

METHODS

We used human bone marrow samples, RPMI 8226 cells, and THP-1 monocytes to investigate CCL3/CCR5 axis. ELISA measured CCL3/CCR5 levels. Knockdown/overexpression vectors modulated expression. Cell proliferation, apoptosis, and macrophage polarization were assessed using CCK8, flow cytometry, and transwell assays. QRT-PCR analyzed CCL3 expression, and western blotting examined PI3K/AKT/RhoA signaling. CCR5 was targeted via siRNAs or MVC. NOD/SCID mouse model evaluated CCL3/CCR5 effects on macrophage polarization and MVC's impact on Bortezomib efficacy.

RESULTS

CCL3, CCR5, and M2 macrophage markers are upregulated in MM patients, with CCL3/CCR5 expression correlating with M2 macrophage polarization. Myeloma-secreted CCL3 and paracrine CCR5 significantly promoted M2 macrophage polarization by activating PI3K/AKT/RhoA signaling, which in turn enhanced myeloma proliferation, inhibited apoptosis, and reduced Bortezomib sensitivity. MVC inhibited M2 macrophage polarization and improved Bortezomib sensitivity in vitro and xenograft mouse myeloma models.

CONCLUSIONS

MVC reduced macrophage polarization and enhanced Bortezomib sensitivity in MM cells.

Cancer stem cells and tumor-associated macrophages as mates in tumor progression: mechanisms of crosstalk and advanced bioinformatic tools to dissect their phenotypes and interaction

Cancer stem cells (CSCs) are a small subset within the tumor mass significantly contributing to cancer progression through dysregulation of various oncogenic pathways, driving tumor growth, chemoresistance and metastasis formation. The aggressive behavior of CSCs is guided by several intracellular signaling pathways such as WNT, NF-kappa-B, NOTCH, Hedgehog, JAK-STAT, PI3K/AKT1/MTOR, TGF/SMAD, PPAR and MAPK kinases, as well as extracellular vesicles such as exosomes, and extracellular signaling molecules such as cytokines, chemokines, pro-angiogenetic and growth factors, which finely regulate CSC phenotype. In this scenario, tumor microenvironment (TME) is a key player in the establishment of a permissive tumor niche, where CSCs engage in intricate communications with diverse immune cells. The "oncogenic" immune cells are mainly represented by B and T lymphocytes, NK cells, and dendritic cells. Among immune cells, macrophages exhibit a more plastic and adaptable phenotype due to their different subpopulations, which are characterized by both immunosuppressive and inflammatory phenotypes. Specifically, tumor-associated macrophages (TAMs) create an immunosuppressive milieu through the production of a plethora of paracrine factors (IL-6, IL-12, TNF-alpha, TGF-beta, CCL1, CCL18) promoting the acquisition by CSCs of a stem-like, invasive and metastatic phenotype. TAMs have demonstrated the ability to communicate with CSCs via direct ligand/receptor (such as CD90/CD11b, LSECtin/BTN3A3, EPHA4/Ephrin) interaction. On the other hand, CSCs exhibited their capacity to influence immune cells, creating a favorable microenvironment for cancer progression. Interestingly, the bidirectional influence of CSCs and TME leads to an epigenetic reprogramming which sustains malignant transformation. Nowadays, the integration of biological and computational data obtained by cutting-edge technologies (single-cell RNA sequencing, spatial transcriptomics, trajectory analysis) has significantly improved the comprehension of the biunivocal multicellular dialogue, providing a comprehensive view of the heterogeneity and dynamics of CSCs, and uncovering alternative mechanisms of immune evasion and therapeutic resistance. Moreover, the combination of biology and computational data will lead to the development of innovative target therapies dampening CSC-TME interaction. Here, we aim to elucidate the most recent insights on CSCs biology and their complex interactions with TME immune cells, specifically TAMs, tracing an exhaustive scenario from the primary tumor to metastasis formation.

OTUD4-mediated inhibition of YAP1 signaling pathway in ovarian cancer: Implications for macrophage polarization and recruitment

Ovarian cancer is a malignancy gynecologic oncology with high incidence and high mortality rate. M2-like tumor-associated macrophages promote cancer cell migration and metastasis. Ovarian tumor family deubiquitinase 4 (OTUD4) belongs to deubiquitinating enzyme family. The roles of OTUD4 in tumor microenvironments in ovarian cancer remains unknow. In this work, OTUD4 was overexpressed or knocked down in high-grade serous ovarian cancer cells OVCAR8 and CAOV3. Ovarian cells were co-cultured with THP-1 macrophages to simulate the tumor microenvironment. We found that OTUD4-expressed ovarian cells inhibited macrophage chemotaxis and M2 polarization. Besides, in ovarian tumor-bearing mouse model, OTUD4 suppressed tumor metastasis and remodeling tumor-associated macrophages phenotype (pro-tumor M2 to anti-tumor M1). In mechanism, OTUD4 protein bound to YAP1 protein, and downregulation of OTUD4 enhanced K63 ubiquitination and nuclear translocation of YAP1, thus increasing CCL2 transcription and subsequent macrophage recruitment. OTUD4 might inhibit CCL2 expression to regulate tumor-associated macrophages in ovarian tumor microenvironment. Those findings present a potential therapeutic strategy for ovarian cancer.

Mechanisms and strategies of immunosenescence effects on non-small cell lung cancer (NSCLC) treatment: A comprehensive analysis and future directions

Non-small cell lung cancer (NSCLC), the most prevalent form of lung cancer, remains a leading cause of cancer-related mortality worldwide, particularly among elderly individuals. The phenomenon of immunosenescence, characterized by the progressive decline in immune cell functionality with aging, plays a pivotal role in NSCLC progression and contributes to the diminished efficacy of therapeutic interventions in older patients. Immunosenescence manifests through impaired immune surveillance, reduced cytotoxic responses, and increased chronic inflammation, collectively fostering a pro-tumorigenic microenvironment. This review provides a comprehensive analysis of the molecular, cellular, and genetic mechanisms of immunosenescence and its impact on immune surveillance and the tumor microenvironment (TME) in NSCLC. We explore how aging affects various immune cells, including T cells, B cells, NK cells, and macrophages, and how these changes compromise the immune system's ability to detect and eliminate tumor cells. Furthermore, we address the challenges posed by immunosenescence to current therapeutic strategies, particularly immunotherapy, which faces significant hurdles in elderly patients due to immune dysfunction. The review highlights emerging technologies, such as single-cell sequencing and CRISPR-Cas9, which offer new insights into immunosenescence and its potential as a therapeutic target. Finally, we outline future research directions, including strategies for rejuvenating the aging immune system and optimizing immunotherapy for older NSCLC patients, with the goal of improving treatment efficacy and survival outcomes. These efforts hold promise for the development of more effective, personalized therapies for elderly patients with NSCLC.

Immunomodulatory and anti-ovarian cancer effects of novel astragalus polysaccharide micelles loaded with podophyllotoxin

Ovarian cancer, a highly lethal form of gynecological cancer globally, has witnessed notable advancements in its treatment through the integration of nanotechnology and immunotherapy. Here, we designed a novel astragalus polysaccharide vector (PDA), encapsulating podophyllotoxin (PPT), and modifying methotrexate (DSPE-PEG2000-MTX) on its surface for targeting ovarian cancer cells with high folate receptor expression. We prepared novel MTX-modified PPT-loaded astragalus polysaccharide micelles (MTX-PPT-micelles) by dialysis method and evaluated their characterization, stability, safety and targeting ability. EDU proliferation, apoptosis, wound healing, and macrophage polarization experiments were performed, and a mouse ectopic tumor model and a lung metastasis model were established to evaluate the antitumor effects of MTX-PPT-micelles. The prepared MTX-PPT-micelles had appropriate particle size, good stability and safety, and were able to achieve slow drug release. In vitro and in vivo experiments showed that MTX-PPT-micelles significantly enhanced tumor uptake and apoptosis, and significantly inhibited tumor proliferation, invasion and metastasis processes. In addition, MTX-PPT-micelles could improve tumor immunosuppression by shifting tumor-associated macrophages from M2 to M1 phenotype. In conclusion, this study successfully constructed a novel nano-delivery system to achieve targeted therapy for ovarian cancer by combating tumor cells with immunomodulatory effects on tumor-associated macrophages.

Exosomes as a Therapeutic Strategy in Cancer: Potential Roles as Drug Carriers and Immune Modulators

Exosome-based cancer immunotherapy is advancing quickly on the concept of artificially activating the immune system to combat cancer. They can mechanistically change the tumor microenvironment, increase immune responses, and function as efficient drug delivery vehicles because of their inherent bioactivity, low toxicity, and immunogenicity. Accurate identification of the mechanisms of action of exosomes in tumor environments, along with optimization of their isolation, purification, and characterization methods, is necessary to increase clinical applications. Exosomes can be modified through cargo loading and surface modification to enhance their therapeutic applications, either before or after the donor cells' isolation. These engineered exosomes can directly target tumor cells at the tumor site or indirectly activate innate and adaptive immune responses in the tumor microenvironment. This approach is particularly effective when combined with traditional cancer immunotherapy techniques such as vaccines, immune checkpoints, and CAR-T cells. It can improve anti-tumor responses, induce long-term immunity, and address the limitations of traditional therapies, such as poor penetration in solid tumors and immunosuppressive environments. This review aims to provide a comprehensive and detailed overview of the direct role of engineered exosomes as drug delivery systems and their immunomodulatory effects on tumors as an indirect approach to fighting cancer. Additionally, it will discuss novel immunotherapy options.

Role of the AKT signaling pathway in regulating tumor-associated macrophage polarization and in the tumor microenvironment: A review

Tumor-associated macrophages (TAMs) are present in and are important components of the tumor microenvironment (TME). TAMs differentiate into 2 functionally distinct morphologies, classically activated (M1)-type TAMs and alternatively activated (M2)-type TAMs, when stimulated by different cytokines. The 2 types of TAMs exhibit distinct properties and functions. M1 TAMs secrete high levels of pro-inflammatory and chemotactic factors, exerting proinflammatory, antitumor effects. Conversely, M2 TAMs alter the extracellular matrix, facilitate cellular immune escape, and stimulate tumor angiogenesis, thereby promoting anti-inflammatory responses and tumor growth. The ratio of M1 TAMs to M2 TAMs in the TME is closely related to the prognosis of the tumor. Tumor cells and other cells in the TME can regulate the polarization of TAMs and thus promote tumor progression through the secretion of various substances; however, polarized TAMs can also act on various cells in the TME through the secretion of exosomes, thus forming a positive feedback loop. Therefore, modulating the phenotype of TAMs in the TME or blocking the polarization of M2 TAMs might be a new approach for cancer treatment. However, the intracellular signaling pathways involved in the polarization of TAMs are poorly understood. The AKT signaling pathway is an important signaling pathway involved in the polarization, growth, proliferation, recruitment, and apoptosis of TAMs, as well as the action of TAMs on other cells within the TME. This paper reviews the AKT signaling pathway in the polarization of TAMs and the regulation of the TME and provides new ideas for tumor immunotherapy.

Pregnancy is associated with the prognosis of ovarian cancer patients with abdominal metastasis

This study aims to explore a new approach to reduce the recurrence risk and improve the prognosis of ovarian cancer (OC) patients with abdominal metastasis by analyzing the clinical characteristics and prognostic factors. A total of 292 OC patients with abdominal metastasis, treated at Henan Provincial People's Hospital between 2021 and 2023 were included in this retrospective study. Follow-up was conducted for one year to observe the recurrence, with 285 patients completing the observation. The patients were then categorized into relapsing and non-relapsing groups based on whether they experienced a relapse within one-year follow-up. Independent sample t-tests and χ 2 tests were used for inter-group comparison. Both univariate and multivariate logistic regression analyses were utilized to screen factors affecting recurrence. The variance inflation factor (VIF) was used to analyze whether the variables in the model had multicollinearity. Receiver Operating Characteristic (ROC) curves and nomographs were used to construct models for predicting one-year recurrence in OC patients with abdominal metastasis. Area under curve (AUC) of ROC and Hosmer-Lemeshow goodness of fit test were used to evaluate the accuracy of the model. The prediction model was verified by internal verification and external verification. The number of pregnancies, the number of births, diabetes mellitus, tumor diameter, tumor reduction combined with intraperitoneal chemotherapy, CA-125, HE-4, NLR, PLR, MLR showed association with patient recurrence. Logistic regression analysis revealed that lower pregnancy frequency and elevated levels of CA-125, HE-4, PLR and MLR were independent risk factors for increased risk of recurrence. In addition, the nomogram-based model demonstrated strong predictive accuracy for one-year recurrence. OC patients with abdominal metastasis present diverse clinical manifestations, among which fewer pregnancies and elevated levels of CA-125, HE-4, PLR, and MLR may be independent risk factors for increased risk of recurrence. Individualized interventions based on these prognostic factors are essential to reduce risk and enhance patient quality of life.

Unveiling novel biomarkers for platinum chemoresistance in ovarian cancer

Primary chemoresistance to platinum-based treatment is observed in approximately 33% of individuals diagnosed with ovarian cancer; however, conventional clinical markers exhibit limited predictive value for chemoresistance. This study aimed to discover new genetic markers that can predict primary resistance to platinum-based chemotherapy. Through the analysis of three GEO datasets (GSE114206, GSE51373, and GSE63885) utilizing bioinformatics methodologies, we identified two specific genes, MFAP4 and EFEMP1. The findings revealed that the areas under the receiver operating characteristic curves for MFAP4 and EFEMP1 were 0.716 and 0.657 in the training cohort, and 0.629 and 0.746 in the testing cohort, respectively. In all cases or in cases treated with platin, high expression of MFAP4 and EFEMP1 was linked to shortened overall survival and progression-free survival. MFAP4 and EFEMP1 were positively correlated with epithelial-mesenchymal transition, TGF-β signaling, KRAS signaling, and so on. The high expression groups of MFAP4 and EFEMP1 exhibited elevated stromal, immune, and ESTIMATE scores. Finally, we constructed a regulatory network involving lncRNA-miRNA-mRNA interactions. In summary, MFAP4 and EFEMP1 have the potential to serve as predictive indicators for both response to platinum-based chemotherapy and survival rates, and might be regarded as innovative biomarkers and therapeutic targets for OC patients.

Setting "cold" tumors on fire: Cancer therapy with live tumor-targeting bacteria

Immunotherapy with checkpoint blockade has shown remarkable efficacy in many patients with a variety of different types of cancer. However, the majority of patients with cancer have yet to benefit from this revolutionary therapy. Studies have shown that checkpoint blockade works best against immune-inflamed tumors characterized by the presence of tumor-infiltrating lymphocytes (TILs). In this review, we summarize studies using live tumor-targeting bacteria to treat cancer and describe various strategies to engineer the tumor-targeting bacteria for maximized immunoregulatory effects. We propose that tumor-localized infections by such engineered bacteria can create an immune microenvironment in favor of a more effective antitumor immunity with or without other therapies, such as immune checkpoint blockade (ICB). Finally, we will briefly outline some exemplary oncology clinical trials involving ICB plus live therapeutic bacteria, with a focus on their ability to modulate antitumor immune responses.

The Role of Chronic Inflammation in Pediatric Cancer

Inflammation plays a crucial role in wound healing and the host immune response following pathogenic invasion. However, unresolved chronic inflammation can result in tissue fibrosis and genetic alterations that contribute to the pathogenesis of human diseases such as cancer. Recent scientific advancements exploring the underlying mechanisms of malignant cellular transformations and cancer progression have exposed significant disparities between pediatric and adult-onset cancers. For instance, pediatric cancers tend to have lower mutational burdens and arise in actively developing tissues, where cell-cycle dysregulation leads to gene, chromosomal, and fusion gene development not seen in adult-onset counterparts. As such, scientific findings in adult cancers cannot be directly applied to pediatric cancers, where unique mutations and inherent etiologies remain poorly understood. Here, we review the role of chronic inflammation in processes of genetic and chromosomal instability, the tumor microenvironment, and immune response that result in pediatric tumorigenesis transformation and explore current and developing therapeutic interventions to maintain and/or restore inflammatory homeostasis.

AXL/GAS6 signaling governs differentiation of tumor-associated macrophages in breast cancer

Most epithelial cancers are infiltrated by prognostically relevant myelomonocytic cells. Immunosuppressive tumor associated macrophages (TAMs) and their precursor monocytic myeloid-derived suppressor cells (MDSCs) have previously been associated with worse outcomes in human breast cancer (BCa), yet the mechanism of immunosuppressive TAMs-polarization from myelomonocytic precursors is not completely understood. In this study, we show that persuaded AXL/GAS6 pathway alters macrophage phenotype from HLA-DRhighCD206lowCD163low classical phagocytic into HLA-DRlowCD206highCD163high immunosuppressive ones with accelerated BCa progression, and increased angiogenesis signature and invasion ability of cancer cells at tumor beds. Notably, both AXL and GAS6 expressions are upregulated in human invasive breast carcinoma, with maximum expression in triple negative histology type. Mechanistically, we demonstrate that AXL/GAS6 signaling drives immunosuppression by governing increased immunosuppressive IL10 production while dampening IL-1β expression within the tumor microenvironment (TME) of BCa. Further, AXL/GAS6 signaling promotes angiogenesis through the activation of PI3K/AKT and NF-κB signaling pathways. Our results unveil role of AXL/GAS6 axis in the differentiation of TAMs, which governs malignant growth, and suggest that therapies that uncouple AXL/GAS6 axis may exhibit therapeutic opportunity for otherwise undruggable Triple Negative Breast Cancer (TNBC) patients.

NADPH Oxidases-Inspired Reactive Oxygen Biocatalysts with Electron-Rich Pt Sites to Potently Amplify Immune Checkpoint Blockade Therapy

Clinical immune checkpoint blockade (ICB)-based immunotherapy of malignant tumors only elicits durable responses in a minority of patients, primarily due to the highly immunosuppressive tumor microenvironment. Although inducing immunogenic cell death (ICD) through reactive oxygen biocatalyst represents an attractive therapeutic strategy to amplify ICB, currently reported biocatalysts encounter insurmountable challenges in achieving high ROS-generating activity to induce potent ICD. Here, inspired by the natural catalytic characteristics of NADPH oxidases, the design of efficient, robust, and electron-rich Pt-based redox centers on the non-stoichiometric W18O49 substrates (Pt─WOx) to serve as bioinspired reactive oxygen biocatalysts to potently activate the ICD, which eventually enhance cancer immune responses and amplifies the ICB-based immunotherapy is reported. These studies demonstrate that the Pt─WOx exhibits rapid electron transfer capability and can promote the formation of electron-rich and low oxophilic Pt redox centers for superior reactive oxygen biocatalysis, which enables the Pt─WOx-based inducers to trigger endoplasmic reticulum stress directly and stimulate immune responses potently for amplifying the anti-PD-L1-based ICB therapy. This bioinspired design provides a straightforward strategy to engineer efficient, robust, and electron-rich reactive oxygen biocatalysts and also opens up a new avenue to create efficient ICD inducers for primary/metastatic tumor treatments.

Silencing PCCA Suppresses CRC Growth and Spread by Modulating EMT and M1 Macrophage Polarization

Background: The progression and metastasis of colorectal cancer (CRC) remain major clinical challenges due to a lack of effective therapeutic targets. Our preliminary study identified the upregulation of the propionyl-CoA carboxylase alpha chain (PCCA) gene in CRC, prompting further investigation into its functional roles. Methods: Bioinformatics analysis, colorectal tumor tissues, and CRC cell lines were used to determine PCCA expression. Wound healing, Transwell, and cell counting kit-8 (CCK-8) assays were conducted to evaluate the impacts of PCCA expression on CRC cell migration, invasion, and proliferation. Western blotting was used to assess epithelial-mesenchymal transition (EMT) markers and associated signaling pathways. Mouse models, flow cytometry, and quantitative polymerase chain reaction (PCR) were performed to investigate the influences of PCCA on CRC tumor growth, lung metastasis, and macrophage polarization. Results: PCCA is highly expressed in CRC tumor tissues compared to normal tissues and is associated with a poor prognosis. Knocking down PCCA reduced CRC cell migration, invasion, and proliferation, which were associated with the upregulation of E-cadherin, the downregulation of N-cadherin, Vimentin, and Fibronectin, as well as the inactivation of the extracellular signal-regulated kinase (ERK)/glycogen synthase kinase 3 beta (GSK3β) signaling pathway. Moreover, PCCA knockdown suppressed CRC tumor growth and lung metastasis, accompanied by an increase in M1-macrophage polarization. Conclusion: Knockdown PCCA inhibits the progression and metastasis of CRC, which is associated with EMT reversion, ERK/GSK3β signaling inactivation, and M1-macrophage polarization. These findings suggest that PCCA is a potential target for controlling CRC.

Acylglycerol kinase inhibits macrophage anti-tumor activity via limiting mtDNA release and cGAS-STING-type I IFN response

Background: Tumor associated macrophages (TAMs) are critical components in regulating the immune statuses of the tumor microenvironments. Although TAM has been intensively studied, it is unclear how mitochondrial proteins such as AGK regulate the TAMs' function. Methods: We investigated the AGK function in TAMs using macrophage-specific Agk deficient mice with B16 and LLC syngeneic tumor models. Flow cytometry was used to evaluate the stemness and activation of CD8+ T cells. The enhanced release of mtDNA into the cytosol in the Agk-deficient BMDMs was measured by RT-PCR and immunofluorescence; the cGAS-STING-type I IFN pathway was evaluated by immunoblotting. Mitochondria functions were evaluated by electron microscope and seahorse equipment. Results: We have noted an increased expression of AGK in TAMs of multiple tumor types, which was negatively correlates with the tumor tissue immune scores. In the B16 and LLC tumor models, macrophage Agk-deficient mice have reduced tumor growth and enhanced populations of CD8+ Tpex. AGK-deficient macrophages have increased mitochondrial damage and mtDNA release into the cytosol, which leads to enhanced cGAS-STING-type I IFN activation. Blockade of the type I IFN signaling pathway with anti-IFNAR reversed the phenotype in Agk-deficient mice. Conclusions: Our findings define a critical role of AGK in maintaining the macrophage mitochondrial homeostasis that is associated with mtDNA release and following cGAS-STING activation and type I IFN pathway. Targeting AGK in TAMs may represent a novel strategy to enhance anti-tumoral activity.

Discovery of a non-nucleotide stimulator of interferon genes (STING) agonist with systemic antitumor effect

Agonists of the stimulator of interferon genes (STING) pathway are increasingly being recognized as a promising new approach in the treatment of cancer. Although progress in clinical trials for STING agonists in antitumor applications has been slow, there is still an urgent need for developing new potent STING agonists with versatile potential applications. Herein, we developed and identified a non-nucleotide STING agonist called DW18343. DW18343 showed robust activation across different STING isoforms. Crystallography analysis revealed that DW18343 binds more deeply into the ligand binding domain (LBD) pocket of STING-H232 compared to other agonists such as MSA-2, SR-717, or cGAMP, which likely contributes to its high potency. DW18343 triggered downstream p-TBK1/p-IRF3 signaling, leading to the production of multiple cytokines. Additionally, DW18343 displayed broad and long-lasting antitumor effects in various syngeneic mouse tumor models, whether administered locally or systemically. Moreover, DW18343 induced immune memory to combat the growth of rechallenged tumors. Finally, DW18343 was shown to be an activator of both the innate and adaptive antitumor immunity in tumor tissue, potentially explaining its strong antitumor effects in vivo. In conclusion, DW18343 serves as a novel non-nucleotide STING agonist with systemic antitumor effect through the activation of antitumor immunity.

Construction of a Cancer Stem Cell related Histone Acetylation Regulatory Genes Prognostic Model for Hepatocellular Carcinoma via Bioinformatics Analysis: Implications for Tumor Chemotherapy and Immunity

BACKGROUND

Cancer stem cells (CSC) play an important role in the development of Liver Hepatocellular Carcinoma (LIHC). However, the regulatory mechanisms between acetylation- associated genes (HAGs) and liver cancer stem cells remain unclear.

OBJECTIVE

To identify a set of histone acetylation genes (HAGs) with close associations to liver cancer stem cells (LCSCs), and to construct a prognostic model that facilitates more accurate prognosis assessments for LIHC patients.

METHODS

LIHC expression data were downloaded from the public databases. Using mRNA expression- based stemness indices (mRNAsi) inferred by One-Class Logistic Regression (OCLR), Differentially Expressed Genes (DEGs) (mRNAsi-High VS. mRNAsi-Low groups) were intersected with DEGs (LIHC VS. normal samples), as well as histone acetylation-associated genes (HAGs), to obtain mRNAsi-HAGs. A risk model was constructed employing the prognostic genes, which were acquired through univariate Cox and Least Shrinkage and Selection Operator (LASSO) regression analyses. Subsequently, independent prognostic factors were identified via univariate and multivariate Cox regression analyses and then a nomogram for prediction of LIHC survival was developed. Additionally, immune infiltration and drug sensitivity analysis were performed to explore the relationships between prognostic genes and immune cells. Finally, the expressions of selected mRNAsi-HAGs were validated in the LIHC tumor sphere by quantitative Reverse Transcription Polymerase Chain Reaction (qRT-PCR) assay and western blot analysis.

RESULTS

Among 13 identified mRNAsi-HAGs, 3 prognostic genes (HDAC1, HDAC11, and HAT1) were selected to construct a risk model (mRNAsi-HAGs risk score = 0.02 * HDAC1 + 0.09 * HAT1 + 0.05 * HDAC11). T-stage, mRNAsi, and mRNAsi-HAGs risk scores were identified as independent prognostic factors to construct the nomogram, which was proved to predict the survival probability of LIHC patients effectively. We subsequently observed strongly positive correlations between mRNAsi-HAGs risk score and tumor-infiltrating T cells, B cells and macrophages/monocytes. Moreover, we found 8 drugs (Mitomycin C, IPA 3, FTI 277, Bleomycin, Tipifarnib, GSK 650394, AICAR and EHT 1864) had significant correlations with mRNAsi-HAGs risk scores. The expression of HDAC1 and HDAC11 was higher in CSC-like cells in the tumor sphere.

CONCLUSION

This study constructed a mRNAsi and HAGs-related prognostic model, which has implications for potential immunotherapy and drug treatment of LIHC.

The therapeutic potential of RNA m(6)A in lung cancer

Lung cancer (LC) is a highly malignant and metastatic form of cancer. The global incidence of and mortality from LC is steadily increasing; the mean 5-year overall survival (OS) rate for LC is less than 20%. This frustrating situation may be attributed to the fact that the pathogenesis of LC remains poorly understood and there is still no cure for mid to advanced LC. Methylation at the N6-position of adenosine (N6mA) of RNA (m(6)A) is widely present in human tissues and organs, and has been found to be necessary for cell development and maintenance of homeostasis. However, numerous basic and clinical studies have demonstrated that RNA m(6)A is deregulated in many human malignancies including LC. This can drive LC malignant characteristics such as proliferation, stemness, invasion, epithelial-mesenchymal transition (EMT), metastasis, and therapeutic resistance. Intriguingly, an increasing number of studies have also shown that eliminating RNA m(6)A dysfunction can exert significant anti-cancer effects on LC such as suppression of cell proliferation and viability, induction of cell death, and reversal of treatment insensitivity. The current review comprehensively discusses the therapeutic potential of RNA m(6)A and its underlying molecular mechanisms in LC, providing useful information for the development of novel LC treatment strategies.

Single-cell sequencing in diffuse large B-cell lymphoma: C1qC is a potential tumor-promoting factor

BACKGROUND

Complement component 1q (C1q) is central to the classical complement pathway. High C1q expression has been linked to poor prognosis in patients with cancer. However, the precise mechanism via which C1q contributes to diffuse large B-cell lymphoma (DLBCL) is still unknown. We aimed to explore the potential mechanism by which C1qC promoting DLBCL.

METHODS

Using multiplex immunohistochemistry (mIHC) to identify immunocyte subgroups associated with prognosis in DLBCL tissues. Constructing a risk prediction model based on immunocytes using least absolute shrinkage and selection operator (LASSO) regression. Single-cell sequencing detects the expression level of C1qC in immunocytes in the DLBCL microenvironment. Using Wb and qPCR to detect markers of M2 macrophages after knocking down C1qC, and exploring the interactions between lymphoma cells and macrophages through co-culture. Analyzing clinical data from DLBCL patients to investigate the clinical significance of C1qC+ M2 macrophages. Lastly, using bioinformatics in conjunction with mIHC to elucidate the potential pro-tumor mechanism of C1qC.

RESULTS

First, we found T cell subtypes, neutrophils, and M2 macrophages are associated with prognosis. Subsequently, the risk model identified C1qC as a differential gene relevant to DLBCL prognosis. Furthermore, single-cell sequencing suggested high C1qC expression in M2 macrophages. The expression level of CD163 is significantly lower following siC1qC. Co-culture experiments have shown that M2 macrophages can promote the proliferation of tumor cells and reduce their drug sensitivity. Furthermore, as an independent predictive indicator, high expression of C1qC+ M2 macrophages is associated with poor prognosis in patients. Finally, a positive correlation between increased C1qC expression and immune checkpoints, as well as an increase in the infiltration of regulatory T cells (Tregs) and M2 macrophages.

CONCLUSIONS

C1qC offering new insights into pathogenesis and presenting a potential therapeutic target in DLBCL.

The role of Aha1 in cancer and neurodegeneration

The 90 kDa Heat shock protein (Hsp90) is a family of ubiquitously expressed molecular chaperones responsible for the stabilization and maturation of >400 client proteins. Hsp90 exhibits dramatic conformational changes to accomplish this, which are regulated by partner proteins termed co-chaperones. One of these co-chaperones is called the activator or Hsp90 ATPase activity homolog 1 (Aha1) and is the most potent accelerator of Hsp90 ATPase activity. In conditions where Aha1 levels are dysregulated including cystic fibrosis, cancer and neurodegeneration, Hsp90 mediated client maturation is disrupted. Accumulating evidence has demonstrated that many disease states exhibit large hetero-protein complexes with Hsp90 as the center. Many of these include Aha1, where increased Aha1 levels drive disease states forward. One strategy to block these effects is to design small molecule disruptors of the Hsp90/Aha1 complex. Studies have demonstrated that current Hsp90/Aha1 small molecule disruptors are effective in both models for cancer and neurodegeration.

Spatial transcriptome profiling identifies DTX3L and BST2 as key biomarkers in esophageal squamous cell carcinoma tumorigenesis

BACKGROUND

Understanding the stepwise progression of esophageal squamous cell carcinoma (ESCC) is crucial for developing customized strategies for early detection and optimal clinical management. Herein, we aimed to unravel the transcriptional and immunologic alterations occurring during malignant transformation and identify clinically significant biomarkers of ESCC.

METHODS

Digital spatial profiling (DSP) was performed on 11 patients with early-stage ESCC (pT1) to explore the transcriptional alterations in epithelial, immune cell, and non-immune cell stromal compartments across regions of distinct histology, including normal tissues, low- and high-grade dysplasia, and cancerous tissues. Furthermore, single-cell spatial transcriptomics was performed using the CosMx Spatial Molecular Imaging (SMI) system on 4 additional patients with pT1 ESCC. Immunohistochemical (IHC) analysis was performed on consecutive histological sections of 20 pT1 ESCCs. Additionally, public bulk and single-cell RNA-sequencing (scRNA-seq) datasets were analyzed, and in vitro and in vivo functional studies were conducted.

RESULTS

Spatial transcriptional reprogramming and dynamic cell signaling pathways that determined ESCC progression were delineated. Increased infiltration of macrophages from normal tissues through dysplasia to cancerous tissues occurred. Macrophage subtypes were characterized using the scRNA-seq dataset. Cell-cell communication analysis of scRNA-seq and SMI data indicated that the migration inhibitory factor (MIF)-CD74 axis may exhibit pro-tumor interactions between macrophages and epithelial cells. DSP, SMI, and IHC data demonstrated that DTX3L expression in epithelial cells and BST2 expression in stromal cells increased gradually with ESCC progression. Functional studies demonstrated that DTX3L or BST2 knockdown inhibited ESCC proliferation and migration and decreased M2 polarization of tumor-associated macrophages.

CONCLUSIONS

Spatial profiling comprehensively characterized the molecular and immunological hallmarks from normal tissue to ESCC, guiding the way to a deeper understanding of the tumorigenesis and progression of this disease and contributing to the prevention of ESCC. Within this exploration, we uncovered biomarkers that exhibit a robust correlation with ESCC progression, offering potential new avenues for insightful therapeutic approaches.

The immune mechanisms of acute exacerbations of idiopathic pulmonary fibrosis

Acute exacerbations of idiopathic pulmonary fibrosis (AE-IPF) are the leading cause of mortality among patients with IPF. There is still a lack of effective treatments for AE-IPF, resulting in a hospitalization mortality rate as high as 70%-80%. To reveal the complicated mechanism of AE-IPF, more attention has been paid to its disturbed immune environment, as patients with IPF exhibit deficiencies in pathogen defense due to local immune dysregulation. During the development of AE-IPF, the classical stimulatory signals in adaptive immunity are inhibited, while the nonclassical immune reactions (Th17) are activated, attracting numerous neutrophils and monocytes to lung tissues. However, there is limited information about the specific changes in the immune response of AE-IPF. We summarized the immune mechanisms of AE-IPF in this review.

Harnessing Nanotechnology for Gout Therapy: Colchicine-Loaded Nanoparticles Regulate Macrophage Polarization and Reduce Inflammation

Gout is a disease caused by hyperuricemia, characterized by inflammation reactions triggered by macrophage polarization. Colchicine is a commonly used drug for gout treatment, but its mechanism of action remains unclear. The aim of this study was to investigate the regulatory effect of colchicine on macrophage polarization to enhance the therapeutic effectiveness against gout inflammation. To accomplish this, a mouse model was established, and peripheral blood mononuclear cell samples were collected. Single-cell RNA sequencing was employed to reveal cellular heterogeneity and identify key genes. Molecular docking and experimental validation were performed to confirm the binding between the key genes and colchicine. Lentiviral intervention and biochemical indicator detection were conducted to assess the impact of key genes on gout mice. Additionally, the therapeutic effect of colchicine incorporated into neutrophil membrane-coated nanoparticles was investigated. The study found that macrophage polarization plays a critical role in gout, and AHNAK was identified as the key gene through which colchicine affects macrophage polarization. Lentiviral intervention to decrease AHNAK expression was shown to alleviate joint swelling in gout mice and regulate macrophage polarization. Colchicine encapsulated in R4F peptide-modified neutrophil membrane-coated Pluronic F127 nanoparticle (R4F-NM@F127) nanocarriers inhibited M1 macrophage polarization, induced M2 macrophage polarization, alleviated gout, and minimized toxicity to normal tissues. Colchicine suppressed M1 macrophage polarization and induced M2 macrophage polarization by binding to AHNAK protein, thereby alleviating gout. Colchicine incorporated into R4F-NM@F127 nanocarriers can serve as a targeted therapeutic drug to regulate macrophage polarization, alleviate gout, and reduce toxicity to normal tissues.

The Role of Glycocalyx Diversity and Thickness for Nanoparticle Internalization in M1-/M2-like Macrophages

Very small superparamagnetic iron oxide nanoparticles (VSOPs) show diagnostic value in multiple diseases as a promising MRI contrast agent. Macrophages predominantly ingest VSOPs, but the mechanism remains unclear. This study identifies differences in VSOP uptake between pro-inflammatory M1 and anti-inflammatory M2 macrophages and explores the role of the pericellular glycocalyx. Glycosaminoglycans (GAG) synthesis activities and the pericellular glycocalyx for M1/M2-like macrophages were assessed by RT-qPCR, Click-iT reaction, and WGA-FITC staining. The uptake of europium-VSOP and Synomag by the two subtypes was measured using Prussian blue staining, fluorescent microscopy, and magnetic particle spectroscopy. The findings revealed that M2-like macrophages had higher GAG synthesis activity, a thicker glycocalyx, and increased nanoparticle uptake compared to M1-like macrophages. Enzymatic glycocalyx degradation significantly decreased nanoparticle uptake. This study demonstrates a positive correlation between glycocalyx and nanoparticle uptake that could be exploited for imaging and targeted therapy, particularly in cancer, where macrophage subtypes play distinct roles.

Effect of ubiquitin-specific proteinase 43 on ovarian serous adenocarcinoma and its clinical significance

BACKGROUND

Ovarian cancer stands as a highly aggressive malignancy. The core aim of this investigation is to uncover genes pivotal to the progression and prognosis of ovarian cancer, while delving deep into the intricate mechanisms that govern their impact.

METHODS

The study entailed the retrieval of RNA-seq data and survival data from the XENA database. Outliers were meticulously excluded in accordance with TCGA guidelines and through principal components analysis. The R package 'deseq2' was harnessed to extract differentially expressed genes. WGCNA was employed to prioritise these genes, and Cox regression analysis and survival analysis based on disease-specific time were conducted to identify significant genes. Immunohistochemistry validation was undertaken to confirm the distinct expression of USP43. Furthermore, the influence of USP43 on the biological functions of ovarian cancer cells was explored using techniques such as RNA interference, western blotting, scratch assays, and matrigel invasion assays. The examination of immune infiltration was facilitated via CIBERSORT.

RESULTS

The study unearthed 5195 differentially expressed genes between ovarian cancer and normal tissue, comprising 3416 up-regulated and 1779 down-regulated genes. WGCNA pinpointed 204 genes most intimately tied to tumorigenesis. The previously undisclosed gene USP43 exhibited heightened expression in tumour tissues and exhibited associations with overall survival and disease-specific survival. USP43 emerged as a driver of cell migration (43.27 ± 3.91% vs 19.69 ± 1.94%) and invasion ability (314 ± 32 vs 131 ± 12) through the mechanism of epithelial mesenchymal transition, potentially mediated by the KRAS pathway. USP43 was also identified as a booster of CD4+ T memory resting cell infiltration, while concurrently reducing M1 macrophages within cancer, thereby fostering a milieu with relatively immune suppressive traits. Interestingly, USP43 demonstrated connections with epigenetically regulated-mRNAsi, although not with mRNAsi.

CONCLUSION

This study underscores the role of USP43 in facilitating tumour migration and invasion. It postulates USP43 as a novel therapeutic target for ovarian cancer treatment.