Targeting of tumour-infiltrating macrophages via CCL2/CCR2 signalling as a therapeutic strategy against hepatocellular carcinoma

Gold nanoparticles modulate macrophage polarization to promote skeletal muscle regeneration

Skeletal muscle regeneration is a complex process that depends on the interplay between immune responses and muscle stem cell (MuSC) activity. Macrophages play a crucial role in this process, exhibiting distinct polarization states-M1 (pro-inflammatory) and M2 (anti-inflammatory)-that significantly affect tissue repair outcomes. Recent advancements in nanomedicine have positioned gold nanoparticles (Au NPs) as promising tools for modulating macrophage polarization and enhancing muscle regeneration. This review examines the role of Au NPs in influencing macrophage behavior, focusing on their physicochemical properties, biocompatibility, and mechanisms of action. We discuss how Au NPs can promote M2 polarization, facilitating tissue repair through modulation of cytokine production, interaction with cell surface receptors, and activation of intracellular signaling pathways. Additionally, we highlight the benefits of Au NPs on MuSC function, angiogenesis, and extracellular matrix remodeling. Despite the potential of Au NPs in skeletal muscle regeneration, challenges remain in optimizing nanoparticle design, developing targeted delivery systems, and understanding long-term effects. Future directions should focus on personalized medicine approaches and combination therapies to enhance therapeutic efficacy. Ultimately, this review emphasizes the transformative potential of Au NPs in regenerative medicine, offering hope for improved treatments for muscle injuries and diseases.

Emerging nanomedicines for macrophage-mediated cancer therapy

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

Exosomes Derived from Bone Marrow Mesenchymal Stem Cells Encapsulated in M2 Macrophage Cell Membrane Targeted to Inhibit Joint Periprosthetic Inflammation

Periprosthetic osteolysis (PPOL) is a serious complication following total joint replacement surgery, and exploring treatments for this complication is of significant societal importance. Exosomes derived from bone marrow mesenchymal stem cells (BMSC-Exos, Exos) have diverse cellular functions, such as inhibiting osteoclast formation, suppressing inflammation progression, and promoting M2 macrophage polarization. However, standalone Exosomes are easily recognized and phagocytosed by the immune system, have a short half-life, and lack specificity. This study is based on the homing effect possessed by M2 macrophages under the regulation of various factors. By combining this with cell membrane encapsulation technology and embedding BMSC-Exos within the membrane of M2 macrophages (M2M-Exos), the aim is to inhibit inflammation and treat PPOL. It was found that M2M-Exos can target the PPOL area, enhancing the therapeutic effects of the BMSC-Exos and reducing wear particle-induced cranial osteolysis. Additionally, M2M-Exos provide immune camouflage through the cell membrane, allowing the BMSC-Exos to evade clearance by the mononuclear macrophage system in the body. Therefore, the study demonstrates the targeting ability of M2M-Exos and their unique role in preventing PPOL. These biomimetic nanoparticles establish a targeted nanodrug delivery system for PPOL treatment.

A novel TLR4 accessory molecule drives hepatic oncogenesis through tumor-associated macrophages

Tumor-associated macrophages (TAMs) play a crucial role in the tumor microenvironment, yet the roles and mechanisms of TAMs in inflammation-associated oncogenesis remain enigmatic. We report that protein canopy homolog 2 (CNPY2) functions as a novel TLR4 regulator, promoting cytokine production in macrophages. CNPY2 binds directly to TLR4. Cnpy2 deficiency reduces cell surface expression of TLR4, nuclear translocation of NFκB and cytokine production in macrophages. Macrophage-specific CNPY2 deficiency significantly decreases cytokine production in macrophages and reduces hepatocarcinogenesis in a diethylnitrosamine (DEN)-induced liver cancer model. RNA-sequencing analysis revealed Cnpy2 knockout decreased the mRNA level and cell surface expression of two VEGF receptors, Flt1 and Kdr, compared to those in WT counterparts, resulting in inhibition of macrophage tumor infiltration. Cnpy2 knockout inhibits NFκB2/p52-mediated transcription of Flt1 and Kdr in macrophages. These findings demonstrate that CNPY2 regulates macrophages in both inflammation and hepatocarcinogenesis and may serve as a therapeutic target for cancer.

A comprehensive review on targeting diverse immune cells for anticancer therapy: Beyond immune checkpoint inhibitors

Although immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment, primary resistance and acquired resistance continue to limit their efficacy for many patients. To address resistance and enhance the anti-tumor activity within the tumor immune microenvironment (TIME), numerous therapeutic strategies targeting both innate and adaptive immune cells have emerged. These include combination therapies with ICIs, chimeric antigen receptor T-cell (CAR-T), chimeric antigen receptor macrophages (CAR-Ms) or chimeric antigen receptor natural killer cell (CAR-NK) therapy, colony stimulating factor 1 receptor (CSF1R) inhibitors, dendritic cell (DC) vaccines, toll-like receptor (TLR) agonists, cytokine therapies, and chemokine inhibition. These approaches underscore the significant potential of the TIME in cancer treatment. This article provides a comprehensive and up-to-date review of the mechanisms of action of various innate and adaptive immune cells within the TIME, as well as the therapeutic strategies targeting each immune cell type, aiming to deepen the understanding of their therapeutic potential.

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.

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.

Chemokine (C-C Motif) Ligand 2/CCR2/Extracellular Signal-Regulated Kinase Signal Induced through Cancer Cell-Macrophage Interaction Contributes to Hepatocellular Carcinoma Progression

Tumor-infiltrating macrophages, known as tumor-associated macrophages, play a crucial role in the tumor microenvironment. Herein, immunohistochemistry revealed that intratumoral CD68-positive macrophages are associated with poor prognosis and clinicopathologic factors in patients with hepatocellular carcinoma (HCC). Subsequently, an indirect co-culture system involving HCC cells and peripheral blood-derived macrophages was developed. cDNA microarray analysis revealed that chemokine (C-C motif) ligand 2 (CCL2) was highly expressed in HCC cells co-cultured with macrophages. CCL2 neutralization suppressed proliferation, migration, and phosphorylation of extracellular signal-regulated kinase (Erk) in HCC cells and macrophages enhanced through co-culture. In contrast, recombinant human CCL2 (rhCCL2) addition facilitated these malignant phenotypes and increased Erk phosphorylation levels in HCC cells and macrophages. The primary CCL2 receptor, CCR2, was expressed in HCC cells and macrophages and was up-regulated in co-cultured HCC cells. CCR2 inhibition suppressed malignant phenotypes and reduced phosphorylated levels of Erk enhanced by rhCCL2. Additionally, the inhibition of Erk signal suppressed rhCCL2-enhanced malignant phenotypes. Moreover, serum CCL2 levels were higher in patients with HCC than those in healthy donors. On the basis of immunohistochemistry, CCL2-positive cases with high CCR2 expression and phosphorylated Erk-positive cases exhibited poor survival outcomes. Therefore, CCL2 up-regulation through interactions between HCC cells and macrophages contributed to HCC progression, making the CCL2/CCR2/Erk signal a potential target for HCC treatment.

Tumor-infiltrating myeloid cells; mechanisms, functional significance, and targeting in cancer therapy

Tumor-infiltrating myeloid cells (TIMs), which encompass tumor-associated macrophages (TAMs), tumor-associated neutrophils (TANs), myeloid-derived suppressor cells (MDSCs), and tumor-associated dendritic cells (TADCs), are of great importance in tumor microenvironment (TME) and are integral to both pro- and anti-tumor immunity. Nevertheless, the phenotypic heterogeneity and functional plasticity of TIMs have posed challenges in fully understanding their complexity roles within the TME. Emerging evidence suggested that the presence of TIMs is frequently linked to prevention of cancer treatment and improvement of patient outcomes and survival. Given their pivotal function in the TME, TIMs have recently been recognized as critical targets for therapeutic approaches aimed at augmenting immunostimulatory myeloid cell populations while depleting or modifying those that are immunosuppressive. This review will explore the important properties of TIMs related to immunity, angiogenesis, and metastasis. We will also document the latest therapeutic strategies targeting TIMs in preclinical and clinical settings. Our objective is to illustrate the potential of TIMs as immunological targets that may improve the outcomes of existing cancer treatments.

Downregulation of CCR2 reduces ventricular remodeling after myocardial infarction by splenic nerve neuromodulation in acute and chronic rat models

OBJECTIVES

Pathological remodeling after myocardial infarction (MI) confers the development of heart failure. Our prior research has indicated that splenic nerve neuromodulation mitigates myocardial ischemia-reperfusion injury (IRI) by reducing levels of proinflammatory factors. This study aims to explore the potential therapeutic benefits of splenic nerve neuromodulation in MI and the underlying mechanism.

METHODS

Splenic nerve neuromodulation was performed through electrical splenic nerve stimulation (SpNS). In the acute myocardial IRI model, post-mortem analyses encompassed RNA sequencing and a range of molecular biology techniques, with the application of CCR2 antagonists (RS-504393) to inhibit the CCR2. In the chronic MI model, rats underwent echocardiographic assessment four weeks post-MI, after which tissues were harvested.

RESULTS

In the acute IRI model, the negative regulation of chemokines production pathway was enriched by RNA-seq, and SpNS reduced the levels of CCR2, CCL2, and CCL7. The administration of RS-504393 decreased cardiomyocyte apoptosis, reduced myocardial damage, and lowered proinflammatory cytokines levels following myocardial IRI. Additionally, SpNS was shown to inhibit oxidative stress, proinflammatory cytokine levels, and cardiac collagen deposition, as observed four weeks post-MI. SpNS also restrained sympathetic nerve remodeling and improved left ventricular function, in part by downregulating CCR2 in the chronic MI model.

CONCLUSIONS

SpNS demonstrated significant improvements in cardiac function, reductions of cardiac remodeling and inhibitions of excessive sympathetic activation in the chronic MI model by downregulation of CCR2. Our study provides novel evidence that splenic nerve neuromodulation may serve as a potential therapeutic intervention in MI patients.

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.

Harnessing nanoparticles for reshaping tumor immune microenvironment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most prevalent cancers, characterized by high morbidity and mortality rates. Recently, immunotherapy has emerged as a crucial treatment modality for HCC, following surgery, locoregional therapies, and targeted therapies. This approach harnesses the body's immune system to target and eliminate cancer cells, potentially resulting in durable antitumor responses. However, acquired resistance and the tumor immunosuppressive microenvironment (TIME) significantly hinder its clinical application. Recently, advancements in nanotechnology, coupled with a deeper understanding of cancer biology and nano-biological interactions, have led to the development of various nanoparticles aimed at enhancing therapeutic efficacy through specific targeting of tumor tissues. These nanoparticles increase the accumulation of immunotherapeutic drugs within the tumor microenvironment, thereby transforming the TIME. In this review, we provide a concise overview of the fundamental principles governing the TIME landscape in HCC and discuss the rationale for and applications of nanoparticles in this context. Additionally, we highlight existing challenges and potential opportunities for the clinical translation of cancer nanomedicines.

Identifying potential signatures of immune cells in hepatocellular carcinoma using integrative bioinformatics approaches and machine-learning strategies

Hepatocellular carcinoma (HCC) is a malignant tumor regulated by the immune system. Immunotherapy using checkpoint inhibitors has shown encouraging outcomes in a subset of HCC patients. The main challenges in checkpoint immunotherapy for HCC are to expand treatment options and to broaden the beneficiary population. Therefore, the search for potential signatures of immune cells is meaningful in the development of immunotherapy for HCC. The HCC related datasets were downloaded from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA). Differential expression analysis and functional analysis were performed first. Then support vector machine-recursive feature elimination (SVM-RFE), random forests (RF), least absolute shrinkage and selection operation (LASSO), and weighed gene co-expression network analysis (WGCNA) were employed to screen for critical genes, and receiver operating characteristic (ROC) analysis was performed to compare diagnostic performance. Subsequently, single-sample gene set enrichment analysis (ssGSEA) was used to explore the relationship between signatures and immune cells. Finally, we validated the expression of these biomarkers in human HCC samples. 531 overlapping differentially expressed genes (DEGs) were identified. Furthermore, enrichment analysis revealed pathways associated with immune activation processes, immune cell involvement and inflammatory signaling. After using multiple machine-learning strategies, extracellular matrix protein 1 (ECM1), leukemia inhibitory factor receptor (LIFR), sushi repeat containing protein X-linked (SRPX), and thromboxane A2 receptor (TBXA2R) were identified as critical signatures, and exhibited high expression in tumor-adjacent normal tissues. According to the ssGSEA results, ECM1, LIFR, SRPX and TBXA2R were all significantly associated with diverse immune cells, such as monocytes and neutrophils. Moreover, immunostaining of human HCC samples showed that these critical signatures all colocalized with CD14-positive monocytes. Our findings report the potential signatures of immune cells in HCC and confirm that they localize in monocytes of tumor-adjacent normal tissues. ECM1, LIFR, SRPX and TBXA2R could become new potential targets for predictive diagnosis, early intervention and immunotherapy of HCC in the future.

HOXA3 activates USP15 to suppress autophagy and promote M2-type macrophage polarization in renal cell carcinoma via facilitating the deubiquitination of SQSTM1

The disease burden of renal cell carcinoma (RCC) has decreased in recent years with advances in treatment, but its pathogeny still remains elusive. We aim to study the role of homeobox A3 (HOXA3)/ubiquitin-specific peptidase 15 (USP15)/SQSTM1 axis on autophagy and M2-type macrophage polarization in RCC. In this study, cell apoptosis and proliferation were assessed by flow cytometry and CCK-8. Autolysosome fusion was observed by immunofluorescence detection of LC3 and LAMP2. The binding between HOXA3 and USP15 promoter was tested by chromatin immunoprecipitation (ChIP), EMSA, and dual-luciferase reporter assays. Also, the interaction between deubiquitinated enzyme (DUB) USP15 and SQSTM1, and ubiquitinated level of SQSTM1 were determined by co-immunoprecipitation (Co-IP) assay. Expression levels of HOXA3, USP15, C-C motif chemokine 2 (CCL2), CCL2 receptor (CCR2), M2-type macrophages, and autophagy-related markers were measured by Western blot, quantitative reverse transcription PCR (RT-qPCR), ELISA, and immunohistochemistry. Role of HOXA3/USP15 axis was verified by xenograft tumor experiment in vivo. We showed upregulated HOXA3 in RCC tissues and cells, and RCC tissues with metastasis showed higher HOXA3 level. The higher HOXA3 expression was relevant to worse overall survival in patients with RCC. HOXA3 induced RCC cell proliferation, and suppressed autophagy and apoptosis via transcriptionally activating USP15 expression. USP15 then induced deubiquitination modification of SQSTM1 in RCC cells. SQSTM1 supported M2-type macrophage polarization by inducing CCL2 secretion. HOXA3 or USP15 knockdown suppressed tumor growth and M2-type macrophage infiltration in vivo. In conclusion, HOXA3 transcriptionally activates USP15 expression, and upregulated USP15 facilitates the deubiquitination of SQSTM1 in RCC. This process on the one hand suppresses autophagy, on the other hand increases M2-type macrophage polarization through stimulating the secretion of CCL2.NEW & NOTEWORTHY We report a novel finding that highly expressed homeobox A3 (HOXA3) transcriptionally activates the expression of ubiquitin-specific peptidase 15 (USP15), resulting in the promotion of deubiquitination of SQSTM1. This process on the one hand suppresses autophagy in renal cell carcinoma (RCC), on the other hand increases M2-type macrophage polarization in the tumor microenvironment through stimulating the secretion of C-C motif chemokine 2 (CCL2).

Complement C3 of tumor-derived extracellular vesicles promotes metastasis of RCC via recruitment of immunosuppressive myeloid cells

Heterogeneous roles of complement C3 have been implicated in tumor metastasis and are highly context dependent. However, the underlying mechanisms linking C3 to tumor metastasis remain elusive in renal cell carcinoma (RCC). Here, we demonstrate that C3 of RCC cell-derived extracellular vesicles (EVs) contributes to metastasis via polarizing tumor-associated macrophages (TAMs) into the immunosuppressive phenotype and recruiting polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs). Mechanistically, EV C3 induces the secretion of CCL2 and CXCL1 by lung macrophages and subsequently enhances TAM polarization and PMN-MDSC recruitment. Notably, targeting the CCL2/CCR2 or CXCL1/CXCR2 axis with the inhibitors RS504393 or Navarixin, respectively, effectively suppresses lung metastasis induced by RCC-derived C3 in a mouse model. Clinically, RCC patients with high expression of C3 demonstrate poor prognosis. Collectively, our findings reveal that tumor-derived EV C3 induces an immunosuppressive tumor microenvironment via TAMs, and thus promoting RCC metastasis.

The immunomodulatory role of the MAFB gene in hepatocellular carcinoma and its impact on biological activities

OBJECTIVE

The transcription factor MAFB is part of the MAF family and is known to promote hepatocellular carcinoma (HCC) by upregulating cyclin D1. However, its role in HCC immunity and prognosis remains unclear. This study explores the biological function, prognostic significance, and immune impact of MAFB in HCC.

METHODS

Immunohistochemistry was used to analyze MAFB expression in HCC and adjacent non-tumor tissues. RT-qPCR and Western blotting measured MAFB levels in HCC cell lines. Specific siRNA was used to knockdown MAFB in HCCLM3 and MHCC97H cells, followed by assays to evaluate cell proliferation, migration, and colony formation. Data from the TCGA database and online tools TIMER and TISDB were used to assess the relationship between MAFB and immune responses. A prognostic model based on MAFB-related immune genes was established, and drug sensitivity analysis was performed.

RESULTS

MAFB was significantly overexpressed in HCC tissues. Knockdown of MAFB in HCC cell lines reduced their proliferation and migration abilities. The risk model based on MAFB-related immune genes effectively predicted patient prognosis, supported by ROC curves. Gene set enrichment analysis indicated that MAFB is involved in immune-related pathways. Several drugs were identified as potentially sensitive to MAFB expression levels.

CONCLUSION

MAFB plays a significant role in HCC development and immune regulation. The prognostic model combining MAFB-related immune genes provides valuable insights for predicting patient outcomes and identifying potential therapeutic targets.

Suppression of MCP-1, IFN-γ and IL-6 production of HNSCC ex vivo by pembrolizumab added to docetaxel and cisplatin (TP) exceeding those of TP alone is linked to improved survival

Background

Adding pembrolizumab, an anti-PD-1 antibody approved for treatment of head and neck squamous cell carcinoma (HNSCC) to neoadjuvant (induction-) chemotherapy utilizing docetaxel and cisplatin (TP) followed by radiotherapy may improve outcome in larynx organ-preservation (LOP) that is investigated in the European Larynx-Organ preservation Study (ELOS). As biomarkers for response to TP and pembrolizumab +TP are missing but may include cytokines, this work aims on determining cytokines potentially linked to outcome as prognostic markers sufficient to predict and/or monitor response to successful LOP.

Methods

Collagenase IV digests were generated from 47 histopathological confirmed HNSCC tumor samples and seeded in 96-well plates containing pembrolizumab, docetaxel, cisplatin either solely or in binary or ternary combination. According to the FLAVINO protocol, supernatants were collected after 3 days, adherent cells fixed using ethanol, air-dried and pan-cytokeratin positive epithelial cells counted using fluorescence microscopy. The cytokines IL-6, IL-8, IFN-γ, IP-10, MCP-1, TNF-α, and VEGF in the supernatant were quantified by sandwich ELISA.

Results

The mode of interaction between pembrolizumab and TP was assessed and correlated to outcome (overall, disease-specific and progression-free survival of patients). Suppression of MCP-1, IFN-γ and IL-6 production by pembrolizumab + TP exceeding the suppressive effect of TP was detected in the majority of samples and linked to improved survival. Multivariate Cox proportional hazard regression modeling revealed MCP-1, IFN-γ and IL-6 as independent outcome predictors.

Conclusions

Comparing response to TP vs. pembrolizumab vs. TP + pembrolizumab may allow for identification of patients with superior outcome independent from treatment applied.

Spatial heterogeneity of the hepatocellular carcinoma microenvironment determines the efficacy of immunotherapy

Hepatocellular carcinoma (HCC) remains a global health challenge owing to its widespread incidence and high mortality. HCC has a specific immune tolerance function because of its unique physiological structure, which limits the efficacy of chemotherapy, radiotherapy, and molecular targeting. In recent years, new immune approaches, including adoptive cell therapy, tumor vaccines, and oncolytic virus therapy, have shown great potential. As the efficacy of immunotherapy mainly depends on the spatial heterogeneity of the tumor immune microenvironment, it is necessary to elucidate the crosstalk between the composition of the liver cancer immune environment, from which potential therapeutic targets can be selected to provide more appropriate individualized treatment programs. The role of spatial heterogeneity of immune cells in the microenvironment of HCC in the progression and influence of immunotherapy on improving the treatment and prognosis of HCC were comprehensively analyzed, providing new inspiration for the subsequent clinical treatment of liver cancer.

Disruption of tumor-intrinsic PGAM5 increases anti-PD-1 efficacy through the CCL2 signaling pathway

BACKGROUND

Immunosuppressive phenotype compromised immunotherapy efficacy of hepatocellular carcinoma. Tumor cells intrinsic mitochondria dynamics could pass effects on the extracellular microenvironment through mtDNA stress. PGAM5 anchors at mitochondria and regulates mitochondria functions. We aim to explore whether the regulation of tumor-intrinsic PGAM5 on mitochondria affects tumor-infiltrating immune cells in the microenvironment and whether tumor-intrinsic PGAM5 can be a therapeutic target to enhance the immunotherapy efficacy of hepatocellular carcinoma (HCC).

METHODS

We analyzed the correlation of PGAM5 expression and immune cells infiltration using Gene Expression Omnibus (GEO) and The Cancer Genome Atlas Liver Hepatocellular Carcinoma (TCGA-LIHC) data sets based on cibersort algorithm and tumor-tissue arrays from two independent cohorts. To further validate our findings, we established subcutaneous and orthotopic mouse HCC models with tumor-intrinsic Pgam5 deficiency and analyzed tumor-infiltrating immune cells by flow cytometry and single-cell RNA sequencing. Mechanistically, we established an in vitro co-culture system and analyzed proteomics data to find out the bridge between tumor cell PGAM5 and tumor-associated macrophages (TAMs) in the microenvironment. Immunofluorescence, chromatin-immunoprecipitation, ELISA, mass spectrometry were conducted to explore the molecular pathway. Macrophages were depleted to investigate whether the effects of tumor-intrinsic PGAM5 on TAMs could affect immunotherapy efficacy in HCC orthotopic and subcutaneous mouse models.

RESULTS

PGAM5 expression in tumor was positively correlated with M2-phenotype TAM infiltration in patients with both HCC and mouse HCC tumor models. High tumor-intrinsic PGAM5 expression promoting M2 TAMs infiltration correlated with poor clinical-pathological characteristics and prognosis in patients with HCC. Disruption of tumor-intrinsic Pgam5 reduced TAM M2 polarization and inhibited HCC tumor growth in tumor-bearing mice. Mechanistically, in HCC cells PGAM5 deficiency inhibited mitochondria fission by promoting TRIM28 binding with DRP1, which increased ubiquitination and degradation of DRP1. Tumor-intrinsic PGAM5 deficiency mediated mitochondria fusion and reduced cytosolic mtDNA stress which attenuated TLR9 activation and downstream NF-κB-regulated CCL2 secretion. Furthermore, disruption of tumor-intrinsic Pgam5 significantly facilitated CD8+ T cells activation and improved anti-programmed cell death protein-1 therapeutic efficacy with macrophages depletion compromising synergistic antitumor immune response.

CONCLUSION

Our results shed light on the effect of tumor mitochondria dynamics on TAMs in tumor microenvironment. Tumor-intrinsic PGAM5 can be a therapeutic target to improve immunotherapy efficacy in patients with HCC.

Targeting SLITRK4 Restrains Proliferation and Liver Metastasis in Colorectal Cancer via Regulating PI3K/AKT/NFκB Pathway and Tumor-Associated Macrophage

Liver metastasis is the major cause of death in colorectal cancer (CRC) due to the lack of effective treatment. To explore novel drivers of CRC liver metastasis, the transcriptomes of primary paracancerous, colorectal tumors and metastases from human patients are profiled. It is found that SLIT- and NTRK-like family member 4 (SLITRK4) is the top upregulated gene in liver metastases and is associated with worse overall survival of CRC patients. Multiple in vitro and in vivo models suggested SLITRK4 promoted CRC tumorigenesis, invasion, migration, and angiogenesis, and inhibition of it restrained CRC tumor growth and liver metastasis with a more profound effect on the tumor microenvironment (TME). Mechanistically, SLITRK4 overexpression significantly activated the PI3K/AKT/NFκB pathway, regulated extracellular matrix organization, and multiple cytokines expression. Furthermore, the results from coculture models and single-cell RNA sequencing analyses suggested SLITRK4 promoted tumor-associated macrophages (TAMs) infiltration and polarization. In addition, macrophage depletion significantly inhibited SLITRK4-induced liver metastasis in CRC. Finally, pharmacological inhibition of SLITRK4 by using lipid-polymer hybrid nanoparticles (NPs) for systemic siRNA delivery can effectively inhibit CRC liver metastasis. Taken together, these results pinpoint that SLITRK4 regulates CRC tumorigenesis and liver metastasis, and siRNA delivering NPs agents validate the therapeutic potential of targeting SLITRK4 in CRC.

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

BACKGROUND

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

AIM OF REVIEW

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

KEY SCIENTIFIC CONCEPTS OF OVERVIEW

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

The interplay between the tumor microenvironment and tumor-derived small extracellular vesicles in cancer development and therapeutic response

The tumor microenvironment (TME) plays an essential role in tumor cell survival by profoundly influencing their proliferation, metastasis, immune evasion, and resistance to treatment. Extracellular vesicles (EVs) are small particles released by all cell types and often reflect the state of their parental cells and modulate other cells' functions through the various cargo they transport. Tumor-derived small EVs (TDSEVs) can transport specific proteins, nucleic acids and lipids tailored to propagate tumor signals and establish a favorable TME. Thus, the TME's biological characteristics can affect TDSEV heterogeneity, and this interplay can amplify tumor growth, dissemination, and resistance to therapy. This review discusses the interplay between TME and TDSEVs based on their biological characteristics and summarizes strategies for targeting cancer cells. Additionally, it reviews the current issues and challenges in this field to offer fresh insights into comprehending tumor development mechanisms and exploring innovative clinical applications.

-RAMP3 promotes hepatocellular carcinoma tumor cell-mediated CCL2 degradation by supporting membrane distribution of ACKR2

This study aimed to explore the potential bind of Receptor Activity-Modifying Protein 3 (RAMP3) with atypical chemokine receptor 2 (ACKR2), and their cooperative regulation on the degradation of the immunosuppressive chemokine CCL2 in the tumor microenvironment of HCC. Bioinformatic analysis was conducted using available bulk-tissue RNA-seq, single-cell RNA-seq, and protein-protein interaction datasets. Human HCC cell line Huh7 and HepG2 and mouse HCC cell line Hepa1-6 were utilized for experiments. Results showed that RAMP3 binds with ACKR2 in HCC tumor cells and promotes the membrane distribution of ACKR2 through RAB4-positive vesicles. RAMP3 promotes CCL2 scavenging through ACKR2 in HCC cells. Mouse RAMP3 inhibited the proliferation of mouse liver cancer cell line (Hepa1-6)-derived syngeneic tumors through ACKR2, reduced the intratumoral concentration of CCL2 in the tumor, and inhibited the phosphorylation of Signal Transducer and Activator of Transcription 3 (STAT3) and protein kinase B (AKT). In addition, mouse RAMP3 inhibited CD11b+/Gr-1 + myeloid cell infiltration and neovascularization in the tumors through ACKR2. In TCGA-LIHC, RAMP3low/ACKR2low group had the worst progression-free interval (PFI), while the RAMP3high/ACKR2high group had the best overall survival (OS). In summary, restoring RAMP3 expression in HCC cells may generate synergistic support for the anticancer effect of ACKR2.

Pinpointing the integration of artificial intelligence in liver cancer immune microenvironment

Liver cancer remains one of the most formidable challenges in modern medicine, characterized by its high incidence and mortality rate. Emerging evidence underscores the critical roles of the immune microenvironment in tumor initiation, development, prognosis, and therapeutic responsiveness. However, the composition of the immune microenvironment of liver cancer (LC-IME) and its association with clinicopathological significance remain unelucidated. In this review, we present the recent developments related to the use of artificial intelligence (AI) for studying the immune microenvironment of liver cancer, focusing on the deciphering of complex high-throughput data. Additionally, we discussed the current challenges of data harmonization and algorithm interpretability for studying LC-IME.

Expanded tumor-associated polymorphonuclear myeloid-derived suppressor cells in Waldenstrom macroglobulinemia display immune suppressive activity

The role of the bone marrow (BM) microenvironment in regulating the antitumor immune response in Waldenstrom macroglobulinemia (WM) remains poorly understood. Here we transcriptionally and phenotypically profiled non-malignant (CD19- CD138-) BM cells from WM patients with a focus on myeloid derived suppressive cells (MDSCs) to provide a deeper understanding of their role in WM. We found that HLA-DRlowCD11b+CD33+ MDSCs were significantly increased in WM patients as compared to normal controls, with an expansion of predominantly polymorphonuclear (PMN)-MDSCs. Single-cell immunogenomic profiling of WM MDSCs identified an immune-suppressive gene signature with upregulated inflammatory pathways associated with interferon and tumor necrosis factor (TNF) signaling. Gene signatures associated with an inflammatory and immune suppressive environment were predominately expressed in PMN-MDSCs. In vitro, WM PMN-MDSCs demonstrated robust T-cell suppression and their viability and expansion was notably enhanced by granulocyte colony stimulating factor (G-CSF) and TNFα. Furthermore, BM malignant B-cells attracted PMN-MDSCs to a greater degree than monocytic MDSCs. Collectively, these data suggest that malignant WM B cells actively recruit PMN-MDSCs which promote an immunosuppressive BM microenvironment through a direct T cell inhibition, while release of G-CSF/TNFα in the microenvironment further promotes PMN-MDSC expansion and in turn immune suppression. Targeting PMN-MDSCs may therefore represent a potential therapeutic strategy in patients with WM.

Leptin/LPS-treated dendritic cells reduce the expression of genes involved in tumor tissue metastasis and angiogenesis in an animal model of breast cancer

Leptin, an immune-regulating protein, enhances the maturation of dendritic cells (DCs). We previously demonstrated that leptin and lipopolysaccharide (LPS) promote the expression of co-stimulatory molecules on the surface of DCs. Leptin/LPS-treated DCs increased T cell responses against 4T1 breast cancer in mice. Therefore, in the present study, we investigate the effects of a DC vaccine treated with leptin and LPS on the genes involved in tumor metastasis, angiogenesis, and related cytokines in a mouse model of breast cancer. Tumor induction was achieved through subcutaneous injection of 4T1 cells into syngeneic mice. On days 12 and 19, the mouse groups received the DC vaccine treated with leptin and a combination of leptin and LPS. After sacrificing the mice on day 26, the levels of IL-6 and IL-33 in the serum were assayed using the ELISA technique, and the expression levels of the VEGF, CCL2, MMP9, and CCL5 genes in the tumors were measured by Real-Time PCR. Compared to untreated tumor-bearing mice, the leptin-treated mature DC (mDC) group exhibited a significant reduction in the expression of MMP9 (0.33-fold, p = 0.01) and CCL5 (0.81-fold, p = 0.02). The leptin-LPS-treated mDC group showed decreased expression of genes involved in metastasis and tumor growth, including VEGF (0.72-fold, p = 0.03), MMP9 (0.26-fold, p = 0.001), and CCL5 (0.3-fold, p = 0.006), indicating more efficient prevention of metastasis. The CCL2 gene expression levels in both treatment groups showed a slight decreasing trend, but these changes were not statistically significant. The leptin-treated mDC group reduced IL-6 production by approximately 16% (p = 0.02), while treatment with the leptin-LPS-treated mDC significantly decreased IL-6 production by approximately 22% (p = 0.01) and increased IL-33 production by approximately 42% (p = 0.03). The findings of the present study indicate that the leptin-LPS-treated mDC vaccine group reduced the expression of genes and cytokines involved in metastasis and angiogenesis, demonstrating greater efficacy compared to the leptin-treated mDC vaccine group.

The Role of Macrophages in Hepatocellular Carcinoma and Their Therapeutic Potential

Hepatocellular carcinoma (HCC) represents a significant clinical burden globally and is predicted to continue to increase in incidence for the foreseeable future. The treatment of HCC is complicated by the fact that, in the majority of cases, it develops on a background of advanced chronic inflammatory liver disease. Chronic inflammation can foster an immunosuppressive microenvironment that promotes tumour progression and metastasis. In this setting, macrophages make up a major immune component of the HCC tumour microenvironment, and in this review, we focus on their contribution to HCC development and progression. Tumour-associated macrophages (TAMs) are largely derived from infiltrating monocytes and their potent anti-inflammatory phenotype can be induced by factors that are found within the tumour microenvironment, such as growth factors, cytokines, hypoxia, and extracellular matrix (ECM) proteins. In general, experimental evidence suggest that TAMs can exhibit a variety of functions that aid HCC tumour progression, including the promotion of angiogenesis, resistance to drug therapy, and releasing factors that support tumour cell proliferation and metastasis. Despite their tumour-promoting profile, there is evidence that the underlying plasticity of these cells can be targeted to help reprogramme TAMs to drive tumour-specific immune responses. We discuss the potential for targeting TAMs therapeutically either by altering their phenotype within the HCC microenvironment or by cell therapy approaches by taking advantage of their infiltrative properties from the circulation into tumour tissue.

Multifaceted Aspects of Dysfunctional Myelopoiesis in Cancer and Therapeutic Perspectives with Focus on HCC

Myelopoiesis provides for the formation and continued renewal of cells belonging primarily to the innate immune system. It is a highly plastic process that secures the response to external and internal stimuli to face acute and changing needs. Infections and chronic diseases including cancer can modulate it by producing several factors, impacting proliferation and differentiation programs. While the lymphocytic compartment has attracted major attention due to the role of adaptive immunity in anticancer immune response, in recent years, research has found convincing evidence that confirms the importance of innate immunity and the key function played by emergency myelopoiesis. Due to cancer's ability to manipulate myelopoiesis to its own advantage, the purpose of this review is to outline myelopoiesis processes within the tumor microenvironment and suggest possible therapeutic lines of research to restore the physiological functioning of the host's immune system, with a special outlook on hepatocellular carcinoma (HCC).

Macrophage crosstalk and therapies: Between tumor cells and immune cells

In the tumor microenvironment, macrophages exhibit different phenotypes and functions in response to various signals, playing a crucial role in the initiation and progression of tumors. Several studies have indicated that intervention in the functions of different phenotypes of tumor-associated macrophages causes significant changes in the crosstalk between tumor cells and immune-related cells, such as T, NK, and B cells, markedly altering the course of tumor development. However, only a few specific therapeutic strategies targeting macrophages are yet available. This article comprehensively reviews the molecular biology mechanisms through which tumor-associated macrophages mediate the crosstalk between tumor cells and immune-related cells. Also, various treatment methods currently used in clinical practice and those in the clinical trial phase have been summarized, and the novel strategies for targeting tumor-associated macrophages have been categorized accordingly.

The causal relationship between immune cells and hepatocellular carcinoma: a Mendelian randomization (MR)

Objective

Hepatocellular carcinoma (HCC) is a complex and multifaceted disease that is increasingly prevalent globally. The involvement of immune cells in the tumour microenvironment has been linked to the progression of HCC, but the exact cause-and-effect relationship is not yet clear. In this study, we utilise Mendelian randomization (MR) to investigate the potential causal links between immune factors and the development of HCC.

Method

We executed a comprehensive MR study, leveraging publicly accessible genetic datasets to explore the potential causal links between 731 types of immune cells and HCC. Our analysis primarily applied inverse variance weighting and weighted median methods. To evaluate the robustness of our findings and probe for the presence of heterogeneity and pleiotropy, we also conducted thorough sensitivity analyses.

Results

We found 36 immune cells were associated with HCC, CD64 on CD14- CD16+ monocytes (OR = 1.328, 95% CI = 1.116- 1.581, p = 0.001), CD3- lymphocyte %lymphocytes (OR = 1.341, 95% CI = 1.027- 1.750, p = 0.031), HLA DR on CD14+ monocytes (OR = 1.256, 95% CI = 1.089- 1.448, p = 0.002), CD19 on CD19 on Plasma Blast-Plasma Cell (OR = 1.224, 95% CI = 1.073- 1.396, p = 0.003), CCR2 on monocytes (OR = 1.204, 95% CI = 1.073- 1.351, p = 0.002) and Naive CD4+ T cell Absolute Count (OR = 0.797, 95% CI = 0.655- 0.969, p = 0.023) were the most strongly associated with HCC. Among them, CD64 on CD14- CD16+ monocytes, CD3 - lymphocyte %lymphocytes, HLA DR on CD14+ monocytes and CD19 on Plasma Blast-Plasma Cells are the risk factors, while Naive CD4+ T cell Absolute Count are protective factors for HCC.

Conclusion

Our MR analysis of the role of immune cells and HCC provides a framework for knowledge of circulating immune status. Systematic assays of infiltrating immune cells in HCC can help dissect the immune status of HCC, assess the current use of checkpoint blockers, and most importantly, aid in the development of innovative immunotherapies. Further research is necessary to validate these findings and explore the underlying mechanisms that influence the immune response to HCC.

MicroRNA-206 as a promising epigenetic approach to modulate tumor-associated macrophages in hepatocellular carcinoma

This letter comments on the recently published manuscript by Huang et al in the World Journal of Gastroenterology, which focused on the immunomodulatory effect of Calculus bovis on hepatocellular carcinoma (HCC) tumor microenvironments (TME) by inhibiting M2-tumor-associated macrophage (M2-TAM) polarization via Wnt/β-catenin pathway modulation. Recent research highlights the crucial role of TAMs and their polarization towards the M2 phenotype in promoting HCC progression. Epigenetic regulation, particularly through microRNAs (miR), has emerged as a key factor in modulating immune responses and TAM polarization in the TME, influencing treatment responses and tumor progression. This editorial focuses on miR-206, which has been found to inhibit HCC cell proliferation and migration and promote apoptosis. Moreover, miR-206 enhances anti-tumor immune responses by promoting M1-polarization of Kupffer cells, facilitating CD8+ T cell recruitment and suppressing liver cancer stem cell expansion. However, challenges remain in understanding the precise mechanisms regulating miR-206 and its potential as a therapeutic agent. Targeting epigenetic mechanisms and improving strategies, whether through pharmacological or genetic approaches, offer promising avenues to sensitize tumor cells to chemotherapy. Understanding the intricate interactions between cancer and non-coding RNA regulation opens new avenues for developing targeted therapies, potentially improving HCC prognosis.

Spatial mapping of the HCC landscape identifies unique intratumoral perivascular-immune neighborhoods

BACKGROUND

HCC develops in the context of chronic inflammation; however, the opposing roles the immune system plays in both the development and control of tumors are not fully understood. Mapping immune cell interactions across the distinct tissue regions could provide greater insight into the role individual immune populations have within tumors.

METHODS

A 39-parameter imaging mass cytometry panel was optimized with markers targeting immune cells, stromal cells, endothelial cells, hepatocytes, and tumor cells. We mapped the immune landscape of tumor, invasive margin, and adjacent nontumor regions across 16 resected tumors comprising 144 regions of interest. X-shift clustering and manual gating were used to characterize cell subsets, and Spectre quantified the spatial environment to identify cellular neighborhoods. Ligand-receptor communication was quantified on 2 single-cell RNA-sequencing data sets and 1 spatial transcriptomic data set.

RESULTS

We show immune cell densities remain largely consistent across these 3 regions, except for subsets of monocyte-derived macrophages, which are enriched within the tumors. Mapping cellular interactions across these regions in an unbiased manner identifies immune neighborhoods comprised of tissue-resident T cells, dendritic cells, and various macrophage populations around perivascular spaces. Importantly, we identify multiple immune cells within these neighborhoods interacting with VEGFA+ perivascular macrophages. VEGFA was further identified as a ligand for communication between perivascular macrophages and CD34+ endothelial cells.

CONCLUSIONS

Immune cell neighborhood interactions, but not cell densities, differ between intratumoral and adjacent nontumor regions in HCC. Unique intratumoral immune neighborhoods around the perivascular space point to an altered landscape within tumors. Enrichment of VEGFA+ perivascular macrophages within these tumors could play a key role in angiogenesis and vascular permeability.

Chemokine CCL2 and its receptor CCR2 in different age groups of patients with COVID-19

BACKGROUND

Despite the development of various antiviral drugs, most of them are not effective in the treatment of coronavirus disease 2019 (COVID-19) as a hyperinflammatory disorder. Chemokine (C-C motif) ligand 2 (CCL2) is one of the critical CC chemokines involved in the pathogenesis and severity of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. This study aimed to investigate the expression of CCL2 and CC chemokine receptor 2 (CCR2) in COVID-19 patients.

METHODS

Peripheral blood samples were collected from 60 confirmed COVID-19 patients and 60 age-matched healthy subjects. The ages of the subjects were categorized as follows: up to 20 years, 20 to 40 years, 40 to 60 years, and more than 60 years. CCL2 serum levels were measured using the enzyme-linked immunosorbent assay (ELISA). CCR2 gene expression in peripheral blood mononuclear cells (PBMCs) was measured employing real-time polymerase chain reaction (PCR).

RESULTS

In all age groups, CCL2 serum levels were significantly elevated in patients compared to healthy controls (P < 0.0001). CCL2 levels were higher in severe patients than in moderate patients. Moreover, CCR2 expression by PBMCs was higher in patients compared to control subjects. However, a significant difference between patients and controls over 60 years of age was identified (P = 0.0353). There was no significant difference in CCR2 expression between moderate and severe COVID-19 patients.

CONCLUSIONS

Taken together, the findings demonstrate that CCL2 and CCR2 are upregulated in COVID-19 patients at protein and mRNA levels, respectively. Therefore, the CCL2/CCR2 axis may be a potential therapeutic target in order to improve patient outcomes.

Iron-loaded cancer-associated fibroblasts induce immunosuppression in prostate cancer

Iron is an essential biomineral in the human body. Here, we describe a subset of iron-loaded cancer-associated fibroblasts, termed as FerroCAFs, that utilize iron to induce immunosuppression in prostate cancer and predict an unfavorable clinical outcome. FerroCAFs secrete myeloid cell-associated proteins, including CCL2, CSF1 and CXCL1, to recruit immunosuppressive myeloid cells. We report the presence of FerroCAFs in prostate cancer from both mice and human, as well as in human lung and ovarian cancers, and identify a conserved cell surface marker, the poliovirus receptor. Mechanistically, the accumulated iron in FerroCAFs is caused by Hmox1-mediated iron release from heme degradation. The intracellular iron activates the Kdm6b, an iron-dependent epigenetic enzyme, to induce an accessible chromatin state and transcription of myeloid cell-associated protein genes. Targeting the FerroCAFs by inhibiting the Hmox1/iron/Kdm6b signaling axis incurs anti-tumor immunity and tumor suppression. Collectively, we report an iron-loaded FerroCAF cluster that drives immunosuppression through an iron-dependent epigenetic reprogramming mechanism and reveal promising therapeutic targets to boost anti-tumor immunity.

Radiotherapy enhances the anti-tumor effect of CAR-NK cells for hepatocellular carcinoma

BACKGROUND

Chimeric antigen receptor (CAR)-NK cell therapy has shown remarkable clinical efficacy and safety in the treatment of hematological malignancies. However, this efficacy was limited in solid tumors owing to hostile tumor microenvironment (TME). Radiotherapy is commonly used for solid tumors and proved to improve the TME. Therefore, the combination with radiotherapy would be a potential strategy to improve therapeutic efficacy of CAR-NK cells for solid tumors.

METHODS

Glypican-3 (GPC3) was used as a target antigen of CAR-NK cell for hepatocellular carcinoma (HCC). To promote migration towards HCC, CXCR2-armed CAR-NK92 cells targeting GPC3 were first developed, and their cytotoxic and migration activities towards HCC cells were evaluated. Next, the effects of irradiation on the anti-tumor activity of CAR-NK92 cells were assessed in vitro and in HCC-bearing NCG mice. Lastly, to demonstrate the potential mechanism mediating the sensitized effect of irradiation on CAR-NK cells, the differential gene expression profiles induced by irradiation were analyzed and the expression of some important ligands for the NK-cell activating receptors were further determined by qRT-PCR and flow cytometry.

RESULTS

In this study, we developed CXCR2-armed GPC3-targeting CAR-NK92 cells that exhibited specific and potent killing activity against HCC cells and the enhanced migration towards HCC cells. Pretreating HCC cells with irradiation enhanced in vitro anti-HCC effect and migration activity of CXCR2-armed CAR-NK92 cells. We further found that only high-dose (8 Gy) but not low-dose (2 Gy) irradiation in one fraction could significantly enhanced in vivo anti-HCC activity of CXCR2-armed CAR-NK92 cells. Irradiation with 8 Gy significantly up-regulated the expression of NK cell-activating ligands on HCC cells.

CONCLUSIONS

Our results indicate the evidence that irradiation could efficiently enhance the anti-tumor effect of CAR-NK cells in solid tumor model. The combination with radiotherapy would be an attractive strategy to improve therapeutic efficacy of CAR-NK cells for solid tumors.

Unleashing nanotechnology to redefine tumor-associated macrophage dynamics and non-coding RNA crosstalk in breast cancer

Breast cancer is a significant global health issue. Tumor-associated macrophages (TAMs) are crucial in influencing the tumor microenvironment and the progression of the disease. TAMs exhibit remarkable plasticity in adopting distinct phenotypes ranging from pro-inflammatory and anti-tumorigenic (M1-like) to immunosuppressive and tumor-promoting (M2-like). This review elucidates the multifaceted roles of TAMs in driving breast tumor growth, angiogenesis, invasion, and metastatic dissemination. Significantly, it highlights the intricate crosstalk between TAMs and non-coding RNAs (ncRNAs), including microRNAs, long noncoding RNAs, and circular RNAs, as a crucial regulatory mechanism modulating TAM polarization and functional dynamics that present potential therapeutic targets. Nanotechnology-based strategies are explored as a promising approach to reprogramming TAMs toward an anti-tumor phenotype. Various nanoparticle delivery systems have shown potential for modulating TAM polarization and inhibiting tumor-promoting effects. Notably, nanoparticles can deliver ncRNA therapeutics to TAMs, offering unique opportunities to modulate their polarization and activity.

Single cell analysis revealed SFRP2 cancer associated fibroblasts drive tumorigenesis in head and neck squamous cell carcinoma

Understanding the mechanisms of invasion and metastasis in head and neck squamous cell carcinoma (HNSCC) is crucial for effective treatment, particularly in metastatic cases. In this study, we analyzed multicenter bulk sequencing and comprehensive single-cell data from 702,446 cells, leading to the identification of a novel subtype of cancer-associated fibroblasts (CAFs), termed Secreted Frizzled-Related Protein2 CAFs (SFRP2_CAFs). These cells, originating from smooth muscle cells, display unique characteristics resembling both myofibroblastic CAFs and inflammatory CAFs, and are linked to poorer survival outcomes in HNSCC patients. Our findings reveal significant interactions between SFRP2_CAFs and SPP1 tumor-associated macrophages, which facilitate tumor invasion and metastasis. Moreover, our research identifies Nuclear factor I/X (NFIX) as a key transcription factor regulating SFRP2_CAFs behavior, confirmed through gene regulatory network analysis and simulation perturbation.

Tumor-associated macrophages: A sentinel of innate immune system in tumor microenvironment gone haywire

The tumor microenvironment (TME) is a critical determinant in the initiation, progression, and treatment outcomes of various cancers. Comprising of cancer-associated fibroblasts (CAF), immune cells, blood vessels, and signaling molecules, the TME is often likened to the soil supporting the seed (tumor). Among its constituents, tumor-associated macrophages (TAMs) play a pivotal role, exhibiting a dual nature as both promoters and inhibitors of tumor growth. This review explores the intricate relationship between TAMs and the TME, emphasizing their diverse functions, from phagocytosis and tissue repair to modulating immune responses. The plasticity of TAMs is highlighted, showcasing their ability to adopt either protumorigenic or anti-tumorigenic phenotypes based on environmental cues. In the context of cancer, TAMs' pro-tumorigenic activities include promoting angiogenesis, inhibiting immune responses, and fostering metastasis. The manuscript delves into therapeutic strategies targeting TAMs, emphasizing the challenges faced in depleting or inhibiting TAMs due to their multifaceted roles. The focus shifts towards reprogramming TAMs to an anti-tumorigenic M1-like phenotype, exploring interventions such as interferons, immune checkpoint inhibitors, and small molecule modulators. Noteworthy advancements include the use of CSF1R inhibitors, CD40 agonists, and CD47 blockade, demonstrating promising results in preclinical and clinical settings. A significant section is dedicated to Chimeric Antigen Receptor (CAR) technology in macrophages (CAR-M cells). While CAR-T cells have shown success in hematological malignancies, their efficacy in solid tumors has been limited. CAR-M cells, engineered to infiltrate solid tumors, are presented as a potential breakthrough, with a focus on their development, challenges, and promising outcomes. The manuscript concludes with the exploration of third-generation CAR-M technology, offering insight into in-vivo reprogramming and nonviral vector approaches. In conclusion, understanding the complex and dynamic role of TAMs in cancer is crucial for developing effective therapeutic strategies. While early-stage TAM-targeted therapies show promise, further extensive research and larger clinical trials are warranted to optimize their targeting and improve overall cancer treatment outcomes.

Spatial analysis reveals targetable macrophage-mediated mechanisms of immune evasion in hepatocellular carcinoma minimal residual disease

Hepatocellular carcinoma (HCC) frequently recurs from minimal residual disease (MRD), which persists after therapy. Here, we identified mechanisms of persistence of residual tumor cells using post-chemoembolization human HCC (n = 108 patients, 1.07 million cells) and a transgenic mouse model of MRD. Through single-cell high-plex cytometric imaging, we identified a spatial neighborhood within which PD-L1 + M2-like macrophages interact with stem-like tumor cells, correlating with CD8+ T cell exhaustion and poor survival. Further, through spatial transcriptomics of residual HCC, we showed that macrophage-derived TGFβ1 mediates the persistence of stem-like tumor cells. Last, we demonstrate that combined blockade of Pdl1 and Tgfβ excluded immunosuppressive macrophages, recruited activated CD8+ T cells and eliminated residual stem-like tumor cells in two mouse models: a transgenic model of MRD and a syngeneic orthotopic model of doxorubicin-resistant HCC. Thus, our spatial analyses reveal that PD-L1+ macrophages sustain MRD by activating the TGFβ pathway in stem-like cancer cells and targeting this interaction may prevent HCC recurrence from MRD.

Regulator of nonsense transcripts 3B is a prognostic biomarker and associated with immune cell infiltration in lung squamous cell and hepatocellular carcinoma

PURPOSE

The characteristic of RENT3B in cancer remains ambiguous. We aimed to study the relationship between RENT3B and immune infiltration in liver hepatocellular carcinoma (LIHC) and lung squamous cell carcinoma (LUSC).

PATIENTS AND METHODS

We investigated the expression levels of RENT3B using ONCOMINE and TIMER databases, and assessed the interrelationship between RENT3B expression and survival using PrognoScan, GEPIA, and Kaplan-Meier plotter. Additionally, we examined the association between RENT3B and immune cells in the tumor microenvironment (TME), as well as markers of immune cells, using TIMER. Subsequently, we performed prognostic analysis based on the expression level of RENT3B within specific immune cell subgroups. Furthermore, we evaluated the promoter methylation profile of RENT3B between tumor and normal tissues in LIHC and LUSC using the DNMIVD database.

RESULTS

RENT3B exhibited increased levels in both in LIHC and LUSC. High RENT3B expression was associated with unfavorable prognosis in LIHC, whereas it indicated a beneficial prognosis in LUSC. In LIHC, the expression of RENT3B positively correlated with immune infiltration levels of B cells, CD4 + T cells, CD8 + T cells, neutrophils, macrophages, and dendritic cells. However, in LUSC, the expression of RENT3B showed a negative correlation with immune infiltration levels of B cells, CD8 + T cells, neutrophils, macrophages, and dendritic cells. RENT3B exhibited positive correlations with 42 immune markers in LIHC, while it displayed negative associations with 10 immune markers in LUSC. Despite variations in immune cell enrichment and reduction subgroups, high RENT3B expression consistently indicated poor prognosis in LIHC, whereas it remained favorable in LUSC. Additionally, there were no significant differences observed in RENT3B promoter methylation between tumor and normal tissues in both LIHC and LUSC.

CONCLUSION

RENT3B can affect the overall tumor prognosis and is associated with immune infiltration, especially in LIHC and LUSC. Consequently, RENT3B can become a prognostic biomarker for LIHC and LUSC.

Causal Effect of Immunocytes, Plasma Metabolites, and Hepatocellular Carcinoma: A Bidirectional Two-Sample Mendelian Randomization Study and Mediation Analysis in East Asian Populations

Background: Hepatocellular carcinoma (HCC) is a primary malignant liver tumor characterized by a low survival rate and high mortality. This study aimed to investigate the causal effect of immune cell phenotypes, plasma metabolites, and HCC in East Asian populations. Methods: The summary results for 731 immunocytes, 1400 plasma metabolites, and HCCs were acquired from publicly available genome-wide association studies (GWASs). This study utilized two-sample Mendelian randomization (MR) analysis to establish causal relationships, which was achieved by employing various statistical methods including inverse variance-weighted, simple mode, MR-Egger, weighted median, and weighted mode. Multiple sensitivity analyses were conducted to confirm the reliability of the MR data. Ultimately, mediation analysis was employed to ascertain the path that leads from immunocytes to plasma metabolites. Results: Among the 20 immune cells and HCC for East Asians, causal links were found, with one showing an inverse correlation. In addition, 36 metabolites were significantly associated with HCC for East Asians. Through analysis of established causative metabolites, we identified a strong correlation between the glycerophospholipid metabolic pathway and HCC for East Asians. By employing a two-step MR analysis, we identified 11 immunocytes that are causally linked to HCC for East Asians through the mediation of 14 plasma metabolites, with Linolenate [α or γ; (18:3n3 or 6)] levels showing the highest mediation proportion (19.3%). Conclusions: Our findings affirm the causal links among immunocytes, plasma metabolites, and HCC in eastern Asia populations by calculating the percentage of the impact that is influenced by plasma metabolites. This study offers innovative perspectives on the early detection, diagnosis, and therapy of HCC.

Macrophage-based cancer immunotherapy: Challenges and opportunities

Macrophages play crucial roles in the tumor microenvironment (TME), exerting diverse functions ranging from promoting tumor growth and metastasis to orchestrating anti-tumor immune responses. Their plasticity allows them to adopt distinct activation states, often called M1-like (pro-inflammatory) and M2-like (anti-inflammatory or pro-tumoral), significantly influencing tumor progression and response to therapy. Harnessing the potential of macrophages in cancer immunotherapy has emerged as a promising strategy, with increasing interest in targeting these cells directly or modulating their functions within the TME. This review explores the intricate interplay between macrophages, the TME, and immunotherapeutic approaches. We discuss the dynamic phenotypic and functional heterogeneity of tumor-associated macrophages (TAMs), their impact on disease progression, and the mechanisms underlying their response to immunotherapy. Furthermore, we highlight recent advancements in macrophage-based immunotherapeutic strategies, including macrophage-targeting agents, adoptive cell transfer, and engineering approaches. Understanding the complex crosstalk between macrophages and the TME is essential for developing effective immunotherapeutic interventions that exploit the immunomodulatory functions of macrophages to enhance anti-tumor immunity and improve clinical outcomes for cancer patients.

Dynamic immunoediting by macrophages in homologous recombination deficiency-stratified pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease, notably resistant to existing therapies. Current research indicates that PDAC patients deficient in homologous recombination (HR) benefit from platinum-based treatments and poly-ADP-ribose polymerase inhibitors (PARPi). However, the effectiveness of PARPi in HR-deficient (HRD) PDAC is suboptimal, and significant challenges remain in fully understanding the distinct characteristics and implications of HRD-associated PDAC. We analyzed 16 PDAC patient-derived tissues, categorized by their homologous recombination deficiency (HRD) scores, and performed high-plex immunofluorescence analysis to define 20 cell phenotypes, thereby generating an in-situ PDAC tumor-immune landscape. Spatial phenotypic-transcriptomic profiling guided by regions-of-interest (ROIs) identified a crucial regulatory mechanism through localized tumor-adjacent macrophages, potentially in an HRD-dependent manner. Cellular neighborhood (CN) analysis further demonstrated the existence of macrophage-associated high-ordered cellular functional units in spatial contexts. Using our multi-omics spatial profiling strategy, we uncovered a dynamic macrophage-mediated regulatory axis linking HRD status with SIGLEC10 and CD52. These findings demonstrate the potential of targeting CD52 in combination with PARPi as a therapeutic intervention for PDAC.

Correlation of Immunomodulatory Cytokines with Tumor Volume and Cerebrospinal Fluid in Vestibular Schwannoma Patients

Sporadic vestibular schwannomas (VSs) often exhibit slow or negligible growth. Nevertheless, some VSs increase significantly in volume within a few months or grow continuously. Recent evidence indicates a role of inflammation in promoting VS growth. Therefore, our study aimed to identify cytokines, which are associated with larger VSs. The expression of different cytokines in VS tumor samples and VS primary cultures was investigated. Additionally, the concentration of cytokines in cell culture supernatants of VS primary cultures and cerebrospinal fluid (CSF) of VS patients and healthy controls were determined. Correlation analysis of cytokine levels with tumor volume, growth rate, Koos grade, age, and hearing was examined with Spearman's-rank test. The mRNA expression of CC-chemokine ligand (CCL) 18, growth differentiation factor (GDF) 15, and interferon regulatory factor 4 correlated positively with tumor volume. Moreover, the amount of GDF15 in the cell culture supernatant of primary cells correlated positively with tumor volume. The concentrations of the cytokines CCL2, CCL5, and CCL18 and transforming growth factor beta (TGFB) 1 in the CSF of the patients were significantly different from those in the CSF controls. Inhibition of immune cell infiltration could be a putative approach to prevent and control VS growth.

Drug-induced senescence by aurora kinase inhibitors attenuates innate immune response of macrophages on gastric cancer organoids

Diffuse-type gastric cancer (DGC) is a subtype of gastric cancer with aggressiveness and poor prognosis. It is of great significance to find sensitive drugs for DGC. In the current study, a total of 20 patient-derived organoids (PDOs) were analyzed for screening the therapeutic efficacy of small molecule kinases inhibitors on gastric cancers, especially the therapeutic difference between intestinal-type gastric cancer (IGCs) and DGCs. The IGCs are sensitive to multiple kinases inhibitors, while DGCs are resistant to most of these kinases inhibitors. It was found that DGCs showed drug-induced senescent phenotype after treatment by aurora kinases inhibitors (AURKi) Barasertib-HQPA and Danusertib. The cell diameter of cancer cells are increased with stronger staining of senescence-associated β-galactosidase (SA-β-GAL), and characteristic appearance of multinucleated giant cells. The senescent cancer cells secrete large amounts of chemokine MCP-1/CCL2, which recruit and induce macrophage to M2-type polarization in PDOs of DGC (DPDOs)-macrophage co-culture system. The up-regulation of local MCP-1/CCL2 can interact with MCP-1/CCL2 receptor (CCR2) expressed on macrophages and suppress their innate immunity to cancer cells. Overall, the special response of DGC to AURKi suggests that clinicians should select a sequential therapy with senescent cell clearance after AURKi treatment for DGC.

Exploring the role of the immune microenvironment in hepatocellular carcinoma: Implications for immunotherapy and drug resistance

Hepatocellular carcinoma (HCC), the most common type of liver tumor, is a leading cause of cancer-related deaths, and the incidence of liver cancer is still increasing worldwide. Curative hepatectomy or liver transplantation is only indicated for a small population of patients with early-stage HCC. However, most patients with HCC are not candidates for radical resection due to disease progression, leading to the choice of the conventional tyrosine kinase inhibitor drug sorafenib as first-line treatment. In the past few years, immunotherapy, mainly immune checkpoint inhibitors (ICIs), has revolutionized the clinical strategy for HCC. Combination therapy with ICIs has proven more effective than sorafenib, and clinical trials have been conducted to apply these therapies to patients. Despite significant progress in immunotherapy, the molecular mechanisms behind it remain unclear, and immune resistance is often challenging to overcome. Several studies have pointed out that the complex intercellular communication network in the immune microenvironment of HCC regulates tumor escape and drug resistance to immune response. This underscores the urgent need to analyze the immune microenvironment of HCC. This review describes the immunosuppressive cell populations in the immune microenvironment of HCC, as well as the related clinical trials, aiming to provide insights for the next generation of precision immunotherapy.

Relationship between CCL2 gene 2518A/G (rs1024611) polymorphism and age-related macular degeneration susceptibility: meta-analysis and trial sequential analysis

PURPOSE

This study aimed to investigate the association between the CC-cytokine ligand-2 (CCL2) 2518A/G (rs1024611) single nucleotide polymorphism (SNP) and susceptibility to age-related macular degeneration (AMD).

METHODS

PubMed, Embase, Web of Science, and other databases were searched for articles published before August 24, 2023. After searching, data extraction, and quality assessment, meta-analysis and trial sequential analysis were conducted using RevMan 5.4, Stata 17.0, and TSA 0.9.5.10 Beta software. Combined OR, P values, and 95% confidence intervals (CIs) were calculated. Sensitivity analysis, subgroup analysis and publication bias assessment were also performed.

RESULTS

Six articles, comprising 1186 cases and 1124 controls, were included. No significant statistical difference was found in six main outcomes. However, due to observed heterogeneity and high sensitivity, subgroup analysis was performed, revealing statistically significant differences across different regions. No significant publication bias was observed. Trial sequential analysis suggested the need for additional follow-up case-control studies to further validate the findings.

CONCLUSION

The CCL2 gene 2518A/G (rs1024611) polymorphism is associated with AMD susceptibility. Among Caucasian populations in West Asia and Europe, the G allele is protective against AMD, whereas in East and South Asia, it poses a risk factor.

New perspectives on chemokines in hepatocellular carcinoma therapy: a critical pathway for natural products regulation of the tumor microenvironment

Hepatocellular carcinoma (HCC) is one of the most common primary neoplasms of the liver and one of the most common solid tumors in the world. Its global incidence is increasing and it has become the third leading cause of cancer-related deaths. There is growing evidence that chemokines play an important role in the tumor microenvironment, regulating the migration and localization of immune cells in tissues and are critical for the function of the immune system. This review comprehensively analyses the expression and activity of chemokines in the TME of HCC and describes their interrelationship with hepatocarcinogenesis and progression. Special attention is given to the role of chemokine-chemokine receptors in the regulation of immune cell accumulation in the TME. Therapeutic strategies targeting tumor-promoting chemokines or the induction/release of beneficial chemokines are reviewed, highlighting the potential value of natural products in modulating chemokines and their receptors in the treatment of HCC. The in-depth discussion in this paper provides a theoretical basis for the treatment of HCC. It is an important reference for new drug development and clinical research.

CCL2 Predicts Survival in Patients with Inoperable Hepatocellular Carcinoma Undergoing Selective Internal Radiotherapy

PURPOSE

Hepatocellular carcinoma (HCC) is the largest subgroup of primary liver tumors. Ablative therapies, such as selective internal radiation therapy (SIRT), are used in late stages for patients with unresectable liver metastases and no response to other therapies. CCL2 (C-C motif chemokine ligand 2) is a potent monocyte chemoattractant. It is associated with tumor progression and metastasis. The role of circulating CCL2 as a biomarker in HCC undergoing selective internal radiation therapy remains unclear.

METHODS

A total of 41 patients (8 female, 33 male) suffering from HCC and undergoing SIRT were enrolled. Pre- and post-therapy changes in circulating CCL2 levels were determined by bead-based immunoassay and compared with clinical laboratory parameters and patient data.

RESULTS

A total of 32 patients exhibited survival beyond 60 days. It was observed that levels of CCL2 correlated with scores indicating a higher likelihood of non-survival and with the severity of the disease. Moreover, a significant inverse correlation was discovered between CCL2 levels and the survival of patients over 60 days in relation to counts of leukocytes, granulocytes, monocytes, and C-reactive protein.

CONCLUSIONS

CCL2 may serve as a potential marker for patient survival after SIRT. The prediction of which HCC patients are likely to benefit from SIRT may be helpful in guiding therapeutic management.

Role of tumor-associated macrophages in hepatocellular carcinoma: impact, mechanism, and therapy

Hepatocellular carcinoma (HCC) is a highly frequent malignancy worldwide. The occurrence and progression of HCC is a complex process closely related to the polarization of tumor-associated macrophages (TAMs) in the tumor microenvironment (TME). The polarization of TAMs is affected by a variety of signaling pathways and surrounding cells. Evidence has shown that TAMs play a crucial role in HCC, through its interaction with other immune cells in the TME. This review summarizes the origin and phenotypic polarization of TAMs, their potential impacts on HCC, and their mechanisms and potential targets for HCC immunotherapy.