Inhibition of APOC1 promotes the transformation of M2 into M1 macrophages via the ferroptosis pathway and enhances anti-PD1 immunotherapy in hepatocellular carcinoma based on single-cell RNA sequencing

Firing up "cold" tumors: Ferroptosis causes immune activation by improving T cell infiltration

Immune checkpoint blocking (ICB), a tumor treatment based on the mechanism of T-cell activation, has shown high efficacy in clinical trials, but not all patients benefit from it. Immune checkpoint inhibitors (ICIs) do not respond to cold tumors that lack effective T-cell infiltration but respond well to hot tumors with sufficient T-cell infiltration. How to convert an unresponsive cold tumor into a responsive hot tumor is an important topic in cancer immunotherapy. Ferroptosis, a newly discovered immunogenic cell death (ICD) form, has great potential in cancer therapy. In the process of deeply understanding the mechanism of cold tumor formation, it was found that ferroptosis showed a powerful immune-activating effect by improving T-cell infiltration, and the combination of ICB therapy significantly enhanced the anti-tumor efficacy. This paper reviews the complex relationship between T cells and ferroptosis, as well as summarizes the various mechanisms by which ferroptosis enhances T cell infiltration: reactivation of T cells and reversal of immunosuppressive tumor microenvironment (TME), as well as recent advances of ICI in combination with targeted ferroptosis therapies, which provides guidance for better improving the ICB efficacy of cold tumors.

Tumor‑associated macrophages activated in the tumor environment of hepatocellular carcinoma: Characterization and treatment (Review)

Hepatocellular carcinoma (HCC) tissue is rich in dendritic cells, T cells, B cells, macrophages, natural killer cells and cellular stroma. Together they form the tumor microenvironment (TME), which is also rich in numerous cytokines. Tumor‑associated macrophages (TAMs) are involved in the regulation of tumor development. TAMs in HCC receive stimuli in different directions, polarize in different directions and release different cytokines to regulate the development of HCC. TAMs are mostly divided into two cell phenotypes: M1 and M2. M1 TAMs secrete pro‑inflammatory mediators, and M2 TAMs secrete a variety of anti‑inflammatory and pro‑tumorigenic substances. The TAM polarization in HCC tumors is M2. Both direct and indirect methods for TAMs to regulate the development of HCC are discussed. TAMs indirectly support HCC development by promoting peripheral angiogenesis and regulating the immune microenvironment of the TME. In terms of the direct regulation between TAMs and HCC cells, the present review mainly focuses on the molecular mechanism. TAMs are involved in both the proliferation and apoptosis of HCC cells to regulate the quantitative changes of HCC, and stimulate the related invasive migratory ability and cell stemness of HCC cells. The present review aims to identify immunotherapeutic options based on the mechanisms of TAMs in the TME of HCC.

RNA m6A modification in ferroptosis: implications for advancing tumor immunotherapy

The pursuit of innovative therapeutic strategies in oncology remains imperative, given the persistent global impact of cancer as a leading cause of mortality. Immunotherapy is regarded as one of the most promising techniques for systemic cancer therapies among the several therapeutic options available. Nevertheless, limited immune response rates and immune resistance urge us on an augmentation for therapeutic efficacy rather than sticking to conventional approaches. Ferroptosis, a novel reprogrammed cell death, is tightly correlated with the tumor immune environment and interferes with cancer progression. Highly mutant or metastasis-prone tumor cells are more susceptible to iron-dependent nonapoptotic cell death. Consequently, ferroptosis-induction therapies hold the promise of overcoming resistance to conventional treatments. The most prevalent post-transcriptional modification, RNA m6A modification, regulates the metabolic processes of targeted RNAs and is involved in numerous physiological and pathological processes. Aberrant m6A modification influences cell susceptibility to ferroptosis, as well as the expression of immune checkpoints. Clarifying the regulation of m6A modification on ferroptosis and its significance in tumor cell response will provide a distinct method for finding potential targets to enhance the effectiveness of immunotherapy. In this review, we comprehensively summarized regulatory characteristics of RNA m6A modification on ferroptosis and discussed the role of RNA m6A-mediated ferroptosis on immunotherapy, aiming to enhance the effectiveness of ferroptosis-sensitive immunotherapy as a treatment for immune-resistant malignancies.

Targeting ferroptosis in autoimmune diseases: Mechanisms and therapeutic prospects

Ferroptosis is a form of regulated cell death that relies on iron and exhibits unique characteristics, including disrupted iron balance, reduced antioxidant defenses, and abnormal lipid peroxidation. Recent research suggests that ferroptosis is associated with the onset and progression of autoimmune disorders such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), inflammatory bowel disease (IBD), and multiple sclerosis (MS). However, the precise effects and molecular mechanisms remain incompletely understood. This article presents an overview of how ferroptosis mechanisms contribute to the development and advancement of autoimmune diseases, as well as the involvement of various immune cells in linking ferroptosis to autoimmune conditions. It also explores potential drug targets within the ferroptosis pathway and recent advancements in therapeutic approaches aimed at preventing and treating autoimmune diseases by targeting ferroptosis. Lastly, the article discusses the challenges and opportunities in utilizing ferroptosis as a potential therapeutic avenue for autoimmune disorders.

Natural killer (NK) cells-related gene signature reveals the immune environment heterogeneity in hepatocellular carcinoma based on single cell analysis

The early diagnosis of liver cancer is crucial for the treatment and depends on the coordinated use of several test procedures. Early diagnosis is crucial for precision therapy in the treatment of the hepatocellular carcinoma (HCC). Therefore, in this study, the NK cell-related gene prediction model was used to provide the basis for precision therapy at the gene level and a novel basis for the treatment of patients with liver cancer. Natural killer (NK) cells have innate abilities to recognize and destroy tumor cells and thus play a crucial function as the "innate counterpart" of cytotoxic T cells. The natural killer (NK) cells is well recognized as a prospective approach for tumor immunotherapy in treating patients with HCC. In this research, we used publicly available databases to collect bioinformatics data of scRNA-seq and RNA-seq from HCC patients. To determine the NK cell-related genes (NKRGs)-based risk profile for HCC, we isolated T and natural killer (NK) cells and subjected them to analysis. Uniform Manifold Approximation and Projection plots were created to show the degree of expression of each marker gene and the distribution of distinct clusters. The connection between the immunotherapy response and the NKRGs-based signature was further analyzed, and the NKRGs-based signature was established. Eventually, a nomogram was developed using the model and clinical features to precisely predict the likelihood of survival. The prognosis of HCC can be accurately predicted using the NKRGs-based prognostic signature, and thorough characterization of the NKRGs signature of HCC may help to interpret the response of HCC to immunotherapy and propose a novel tumor treatment perspective.

Bevacizumab induces ferroptosis and enhances CD8+ T cell immune activity in liver cancer via modulating HAT1 and increasing IL-9

Bevacizumab is a recombinant humanized monoclonal immunoglobulin (Ig) G1 antibody of VEGF, and inhibits angiogenesis and tumor growth in hepatocellular carcinoma (HCC). Ferroptosis, a new form of regulated cell death function independently of the apoptotic machinery, has been accepted as an attractive target for pharmacological intervention; the ferroptosis pathway can enhance cell immune activity of anti-PD1 immunotherapy in HCC. In this study we investigated whether and how bevacizumab regulated ferroptosis and immune activity in liver cancer. Firstly, we performed RNA-sequencing in bevacizumab-treated human liver cancer cell line HepG2 cells, and found that bevacizumab significantly altered the expression of a number of genes including VEGF, PI3K, HAT1, SLC7A11 and IL-9 in liver cancer, bevacizumab upregulated 37 ferroptosis-related drivers, and downregulated 17 ferroptosis-related suppressors in particular. We demonstrated that bevacizumab triggered ferroptosis in liver cancer cells by driving VEGF/PI3K/HAT1/SLC7A11 axis. Clinical data confirmed that the expression levels of VEGF were positively associated with those of PI3K, HAT1 and SLC7A11 in HCC tissues. Meanwhile, we found that bevacizumab enhanced immune cell activity in tumor immune-microenvironment. We identified that HAT1 up-regulated miR-143 targeting IL-9 mRNA 3'UTR in liver cancer cells; bevacizumab treatment resulted in the increase of IL-9 levels and its secretion via VEGF/PI3K/HAT1/miR-143/IL-9 axis, which led to the inhibition of tumor growth in vivo through increasing the release of IL-2 and Granzyme B from activated CD8+ T cells. We conclude that in addition to inhibiting angiogenesis, bevacizumab induces ferroptosis and enhances CD8+ T cell immune activity in liver cancer. This study provides new insight into the mechanisms by which bevacizumab synergistically modulates ferroptosis and CD8+ T cell immune activity in liver cancer.

Hepatocellular carcinoma and AIM2: Therapeutic potential through regulation of autophagy and macrophage polarization

OBJECTIVE

Hepatocellular carcinoma (HCC) poses a significant challenge to global health. Its pathophysiology involves interconnected processes, including cell proliferation, autophagy, and macrophage polarization. However, the role of Absent in Melanoma 2 (AIM2) in HCC remains elusive.

METHODS

The expression of AIM2 in Huh-7 and Hep3B cell lines was manipulated and cell proliferation, autophagy, apoptosis, and migration/invasion, together with the polarization of M2 macrophages, were evaluated. The markers of autophagy pathway, LC3B, Beclin-1, and P62, underwent examination through Western blot analysis. An autophagy inhibitor, 3-MA, was used to measured the role of autophagy in HCC. Finally, the effect of AIM2 overexpression on HCC was further evaluated using a subcutaneous tumor model in nude mice.

RESULTS

Our results established that AIM2 overexpression inhibits HCC cell proliferation, migration, and invasion while promoting apoptosis and autophagy. Conversely, knockdown of AIM2 engendered opposite effects. AIM2 overexpression was correlated with reduced M2 macrophage polarization. The autophagy inhibitor substantiated AIM2's role in autophagy and identified its downstream impact on cell proliferation, migration, invasion, and macrophage polarization. In the in vivo model, overexpression of AIM2 led to the inhibition of HCC tumor growth.

CONCLUSION

The findings underscore AIM2's crucial function in modulating major biological processes in HCC, pointing to its potential as a therapeutic target. This study inaugurally demonstrated that AIM2 activates autophagy and influences macrophage polarization, playing a role in liver cancer progression.

Bioactive polysaccharides mediate ferroptosis to modulate tumor immunotherapy

Polysaccharides from diverse origins exhibit notable bioactivities, particularly their capacity to exert antitumor and immune-enhancing effects. Concurrently, ferroptosis emerges as a distinctive form of regulated cell death characterized by iron-dependent lipid peroxidation, potentially influencing the demise of specific tumor cells and organismal homeostasis. Recent scholarly attention has increasingly focused on utilizing polysaccharides to modulate tumor cell ferroptosis and manipulate cellular immune responses. This article provides an in-depth analysis of contemporary research concerning using polysaccharides to augment antitumor immunity and combat malignancies. Central to our discourse is examining the pivotal role of polysaccharides in mediating ferroptosis, bolstering immune surveillance, and elucidating the interplay between polysaccharides and antitumor immunity. Furthermore, a comprehensive synthesis of the multifaceted roles of polysaccharides in antitumor and immunomodulatory contexts is provided. Recent advances in understanding how polysaccharides enhance immune function by inducing ferroptosis cell death are explained. Lastly, unresolved inquiries are outlined, and potential avenues for future research are proposed, focusing on the translational applications of polysaccharides in antitumor immunotherapy.

The heterogeneity of cellular metabolism in the tumour microenvironment of hepatocellular carcinoma with portal vein tumour thrombus

Given the growing interest in the metabolic heterogeneity of hepatocellular carcinoma (HCC) and portal vein tumour thrombus (PVTT). This study comprehensively analysed the metabolic heterogeneity of HCC, PVTT, and normal liver samples using multi-omics combinations. A single-cell RNA sequencing dataset encompassing six major cell types was obtained for integrated analysis. The optimal subtypes were identified using cluster stratification and validated using spatial transcriptomics and fluorescent multiplex immunohistochemistry. Then, a combined index based meta-cluster was calculated to verify its prognostic significance using multi-omics data from public cohorts. Our study first depicted the metabolic heterogeneity landscape of non-malignant cells in HCC and PVTT at multiomics levels. The optimal subtypes interpret the metabolic characteristics of PVTT formation and development. The combined index provided effective predictions of prognosis and immunotherapy responses. Patients with a higher combined index had a relatively poor prognosis (p <0.001). We also found metabolism of polyamines was a key metabolic pathway involved in conversion of metabolic heterogeneity in HCC and PVTT, and identified ODC1 was significantly higher expressed in PVTT compared to normal tissue (p =0.03). Our findings revealed both consistency and heterogeneity in the metabolism of non-malignant cells in HCC and PVTT. The risk stratification based on cancer-associated fibroblasts and myeloid cells conduce to predict prognosis and guide treatment. This offers new directions for understanding disease development and immunotherapy responses.

Influencing factors and solution strategies of chimeric antigen receptor T-cell therapy (CAR-T) cell immunotherapy

Chimeric antigen receptor T-cesll therapy (CAR-T) has achieved groundbreaking advancements in clinical application, ushering in a new era for innovative cancer treatment. However, the challenges associated with implementing this novel targeted cell therapy are increasingly significant. Particularly in the clinical management of solid tumors, obstacles such as the immunosuppressive effects of the tumor microenvironment, limited local tumor infiltration capability of CAR-T cells, heterogeneity of tumor targeting antigens, uncertainties surrounding CAR-T quality, control, and clinical adverse reactions have contributed to increased drug resistance and decreased compliance in tumor therapy. These factors have significantly impeded the widespread adoption and utilization of this therapeutic approach. In this paper, we comprehensively analyze recent preclinical and clinical reports on CAR-T therapy while summarizing crucial factors influencing its efficacy. Furthermore, we aim to identify existing solution strategies and explore their current research status. Through this review article, our objective is to broaden perspectives for further exploration into CAR-T therapy strategies and their clinical applications.

Machine learning developed a macrophage signature for predicting prognosis, immune infiltration and immunotherapy features in head and neck squamous cell carcinoma

Macrophages played an important role in the progression and treatment of head and neck squamous cell carcinoma (HNSCC). We employed weighted gene co-expression network analysis (WGCNA) to identify macrophage-related genes (MRGs) and classify patients with HNSCC into two distinct subtypes. A macrophage-related risk signature (MRS) model, comprising nine genes: IGF2BP2, PPP1R14C, SLC7A5, KRT9, RAC2, NTN4, CTLA4, APOC1, and CYP27A1, was formulated by integrating 101 machine learning algorithm combinations. We observed lower overall survival (OS) in the high-risk group and the high-risk group showed elevated expression levels in most of the immune checkpoint and human leukocyte antigen (HLA) genes, suggesting a strong immune evasion capacity. Correspondingly, TIDE score positively correlated with risk score, implying that high-risk tumors may resist immunotherapy more effectively. At the single-cell level, we noted macrophages in the tumor microenvironment (TME) predominantly stalled in the G2/M phase, potentially hindering epithelial-mesenchymal transition and playing a crucial role in the inhibition of tumor progression. Finally, the proliferation and migration abilities of HNSCC cells significantly decreased after the expression of IGF2BP2 and SLC7A5 reduced. It also decreased migration ability of macrophages and facilitated their polarization towards the M1 direction. Our study constructed a novel MRS for HNSCC, which could serve as an indicator for predicting the prognosis, immune infiltration and immunotherapy for HNSCC patients.

Identification of a ferroptosis-related prognostic signature and validation of ITGA6-AS1 in enhancing cell proliferation, migration and invasion in glioma

Glioma is the most common malignant tumor of the adult central nervous system. In this study, we aimed to identify a novel model for predicting glioma prognosis and a potential therapeutic target. Here, lncRNAs related to prognosis and ferroptosis were analyzed and screened through R software and online websites. A nomogram model was established and evaluated with calibration curve, receiver operating characteristic curve and decision curve analysis. Further, an enrichment analysis and immune infiltration analysis were performed. In addition, the expression level and biological function of ITGA6-AS1 were verified in vitro. We obtained a ferroptosis-related 7-lncRNA signature, and constructed a nomogram prognostic model with good predictability for 1-, 3- and 5-year overall survival of glioma patients. The enrichment analysis indicated potential involvement of certain pathways and suggested a correlation between the high-risk group and infiltration of M2 macrophages and MDSCs. Furthermore, the expression level of ITGA6-AS1 in the U118, U87, and LN229 cells was upregulated compared to the H1800 cell. Interestingly, knockdown of ITGA6-AS1 may inhibit U118 cells' proliferation, migration and invasion in vitro. while overexpression of ITGA6-AS1 in LN229 cells plays a promoting role. This study implies that the 7-lncRNA signature may contribute to the stratification of glioma prognosis, and the immune suppressive microenvironment may be associated with macrophage-ferroptosis crosstalk. Furthermore, ITGA6-AS1 may be a potential therapeutic target for patients with glioma.

A prognostic model constructed by ferroptosis-associated genes (FAGs) in papillary renal cell carcinoma (PRCC) and its association with tumor mutation burden (TMB) and immune infiltration

BACKGROUND

This study aimed to identify the prognostic-related differentially expressed ferroptosis-associated genes (DEFAGs) in papillary renal cell carcinoma (PRCC).

METHODS

Data encompassing simple nucleotide variation, transcriptome profiles, and relevant clinical information of PRCC patients were sourced from The Cancer Genome Atlas (TCGA) database. The expression matrix of ferroptosis-associated genes (FAGs) was analyzed using the "limma" package in R to identify differentially expressed DEFAGs. Lasso regression analysis, along with univariate and multivariate Cox proportional hazards regressions, was employed to identify independent prognostic-related DEFAGs and formulate a nomogram. Additionally, we examined potential independent survival-related clinical risk factors and compared immune cell infiltration and tumor mutation burden (TMB) differences between high- and low-risk patient groups.

RESULTS

A cohort of 321 patients were analyzed, revealing twelve FAGs significantly influencing the overall survival (OS) of PRCC patients. Among them, two mRNAs (GCLC, HSBP1) emerged as independent prognostic-related DEFAGs. Smoking status, tumor stage, and risk score were identified as independent clinical risk factors for PRCC. Furthermore, notable disparities in immune cell infiltration and function were observed between high- and low-risk groups. GCLC and HSBP1 were associated with various immune cells and functions, TMB, and immune evasion.

CONCLUSION

This finding revealed two independent prognostic-related DEFAGs in PRCC and established a robust prognostic model, offering potential therapeutic targets and promising insights for the management of this disease.

Elucidating the role of S100A10 in CD8+ T cell exhaustion and HCC immune escape via the cPLA2 and 5-LOX axis

Hepatocellular carcinoma (HCC) is a common malignant tumor with a complex immune evasion mechanism posing a challenge to treatment. The role of the S100A10 gene in various cancers has garnered significant attention. This study aims to elucidate the impact of S100A10 on CD8+ T cell exhaustion via the cPLA2 and 5-LOX axis, thereby elucidating its role in immune evasion in HCC. By analyzing the HCC-related data from the GEO and TCGA databases, we identified differentially expressed genes associated with lipid metabolism and developed a prognostic risk model. Subsequently, through RNA-seq and PPI analyses, we determined vital lipid metabolism genes and downstream factors S100A10, ACOT7, and SMS, which were significantly correlated with CD8+ T cell infiltration. Given the most significant expression differences, we selected S100A10 for further investigation. Both in vitro and in vivo experiments were conducted, including co-culture experiments of CD8+ T cells with MHCC97-L cells, Co-IP experiments, and validation in an HCC mouse model. S100A10 was significantly overexpressed in HCC tissues and potentially regulates CD8+ T cell exhaustion and lipid metabolism reprogramming through the cPLA2 and 5-LOX axis. Silencing S100A10 could inhibit CD8+ T cell exhaustion, further suppressing immune evasion in HCC. S100A10 may activate the cPLA2 and 5-LOX axis, initiating lipid metabolism reprogramming and upregulating LTB4 levels, thus promoting CD8+ T cell exhaustion in HCC tissues, facilitating immune evasion by HCC cells, ultimately impacting the growth and migration of HCC cells. This research highlights the critical role of S100A10 via the cPLA2 and 5-LOX axis in immune evasion in HCC, providing new theoretical foundations and potential targets for diagnosing and treating HCC.

Programmed cell death in hepatocellular carcinoma: mechanisms and therapeutic prospects

Hepatocellular Carcinoma (HCC), the most common primary liver cancer, ranks as the third most common cause of cancer-related deaths globally. A deeper understanding of the cell death mechanisms in HCC is essential for developing more effective treatment strategies. This review explores programmed cell death (PCD) pathways involved in HCC, including apoptosis, necroptosis, pyroptosis, ferroptosis, and immunogenic cell death (ICD). These mechanisms trigger specific cell death cascades that influence the development and progression of HCC. Although multiple PCD pathways are involved in HCC, shared cellular factors suggest a possible interplay between the different forms of cell death. However, the exact roles of different cell death pathways in HCC and which cell death pathway plays a major role remain unclear. This review also highlights how disruptions in cell death pathways are related to drug resistance in cancer therapy, promoting a combined approach of cell death induction and anti-tumor treatment to enhance therapeutic efficacy. Further research is required to unravel the complex interplay between cell death modalities in HCC, which may lead to innovative therapeutic breakthroughs.

The immunotherapy mechanism of Hedyotis Diffusae Herba in treating liver cancer: a study based on network pharmacology, bioinformatics, and experimental validation

Liver cancer is a malignant tumor that develops on or inside the liver. Hedyotis diffusa Willd (HDW) plays a significant role in anti-tumor activities; however, its mechanism against liver cancer remains unclear. This study aims to evaluate the immunotherapeutic mechanism of HDW in treating liver cancer through network pharmacology, bioinformatics analysis, and experimental validation. Network pharmacology was utilized to identify the active components and potential targets of HDW from the TCMSP database. A potential target protein-protein interaction (PPI) network was constructed using the STRING database, followed by function and pathway enrichment analysis of the targets using GO and KEGG methods. In addition, the key targets for HDW against liver cancer were identified using five different algorithms in Cytoscape. The TCGA and HPA databases were used to assess the mRNA and protein expression of core target genes in normal liver and liver cancer tissues and their relationship with overall survival in liver cancer, as well as their role in immune infiltration. Molecular docking between the core components of HDW and the core targets was performed using PyMOL software. The effects of HDW on the proliferation and apoptosis of liver cancer cells were examined using MTT and flow cytometry. The regulatory effects of the core component quercetin on core targets were validated using RT-qPCR and Western blot. A total of 163 potential targets were identified by searching for intersections among 7 types of active components and all potential and liver cancer targets. PPI network analysis revealed the core targets IL6 and TNF. GO enrichment analysis involved 2089 biological processes, 76 cellular components, and 196 molecular functions. KEGG enrichment analysis suggested that the anti-cancer effects of HDW might be mediated by the AGE-RAGE signaling pathway, IL-17 signaling pathway, TNF signaling pathway, PI3K-Akt signaling pathway, and NF-κB signaling pathway. Database validation of key targets showed that mRNA and protein expression results for the IL6 gene were contradictory, while those for the TNF gene were consistent, both being underexpressed in liver cancer. Importantly, the expression of IL6 and TNF was related to the infiltration of 24 types of immune cells, with the highest correlation with macrophages. Molecular docking showed that IL6 and TNF had high binding stability with quercetin, with binding energies of - 7.4 and - 6.0 kJ∙mol-1, respectively. Experimental validation showed that quercetin inhibited liver cancer cell proliferation and promoted apoptosis in a dose-dependent manner, with protein results indicating that quercetin downregulated the mRNA and protein expression of IL6 and TNF, and upregulated key proteins in the AGE-RAGE signaling pathway, AGEs, and RAGE. This study comprehensively elucidates the activity, potential targets, and molecular mechanisms of HDW against liver cancer, providing a promising strategy for the scientific basis and treatment mechanism of traditional Chinese medicine in treating liver cancer.

The role of macrophages in fibrosis of chronic kidney disease

Macrophages are widely distributed throughout various tissues of the body, and mounting evidence suggests their involvement in regulating the tissue microenvironment, thereby influencing disease onset and progression through direct or indirect actions. In chronic kidney disease (CKD), disturbances in renal functional homeostasis lead to inflammatory cell infiltration, tubular expansion, glomerular atrophy, and subsequent renal fibrosis. Macrophages play a pivotal role in this pathological process. Therefore, understanding their role is imperative for investigating CKD progression, mitigating its advancement, and offering novel research perspectives for fibrosis treatment from an immunological standpoint. This review primarily delves into the intrinsic characteristics of macrophages, their origins, diverse subtypes, and their associations with renal fibrosis. Particular emphasis is placed on the transition between M1 and M2 phenotypes. In late-stage CKD, there is a shift from the M1 to the M2 phenotype, accompanied by an increased prevalence of M2 macrophages. This transition is governed by the activation of the TGF-β1/SMAD3 and JAK/STAT pathways, which facilitate macrophage-to-myofibroblast transition (MMT). The tyrosine kinase Src is involved in both signaling cascades. By thoroughly elucidating macrophage functions and comprehending the modes and molecular mechanisms of macrophage-fibroblast interaction in the kidney, novel, tailored therapeutic strategies for preventing or attenuating the progression of CKD can be developed.

The evolving process of ferroptosis in thyroid cancer: Novel mechanisms and opportunities

Thyroid cancer (TC) is a prevalent endocrine malignancy, with a significant increase in incidence worldwide. Ferroptosis is a novel form of programmed cell death, primarily caused by iron overload and reactive oxygen species (ROS)-dependent accumulation of lipid peroxides. The main manifestations of cellular ferroptosis are rupture of the outer membrane, crumpling of the mitochondria and shrinkage or disappearance of the mitochondrial cristae, thus leading to cell death. Ferroptosis is an important phenomenon in tumour progression, with crosstalk with tumour-associated signalling pathways profoundly affecting tumour progression, immune effects and treatment outcomes. The functions and mechanisms of ferroptosis in TC have also attracted increasing attention, mainly in terms of influencing tumour proliferation, invasion, migration, immune response, therapeutic susceptibility and genetic susceptibility. However, at present, the tumour biology of the morphological, biological and mechanism pathways of ferroptosis is much less deep in TC than in other malignancies. Hence, in this review, we highlighted the emerging role of ferroptosis in TC progression, including the novel mechanisms and potential opportunities for diagnosis and treatment, as well as discussed the limitations and prospects. Ferroptosis-based diagnostic and therapeutic strategies can potentially provide complementary management of TCs.

S100P facilitates LUAD progression via PKA/c-Jun-mediated tumor-associated macrophage recruitment and polarization

S100P, a member of the S100 calcium-binding protein family, is closely associated with abnormal proliferation, invasion, and metastasis of various cancers. However, its role in the lung adenocarcinoma (LUAD) tumor microenvironment (TME) remains unclear. In this study, we observed specific expression of S100P on tumor cells in LUAD patients through tissue immunofluorescence analysis. Furthermore, this expression was strongly correlated with the recruitment and polarization of tumor-associated macrophages (TAMs). Bioinformatics analysis revealed that high S100P expression is associated with poorer overall survival in LUAD patients. Subsequently, a subcutaneous mouse model demonstrated that S100P promotes recruitment and polarization of TAMs towards the M2 type. Finally, in vitro studies on LUAD cells revealed that S100P enhances the secretion of chemokines and polarizing factors by activating the PKA/c-Jun pathway, which is implicated in TAM recruitment and polarization towards the M2 phenotype. Moreover, inhibition of c-Jun expression impedes the ability of TAMs to infiltrate and polarize towards the M2 phenotype. In conclusion, our study demonstrates that S100P facilitates LUAD cells growth by recruiting M2 TAMs through PKA/c-Jun signaling, resulting in the production of various cytokines. Considering these findings, S100P holds promise as an important diagnostic marker and potential therapeutic target for LUAD.

ATG5-mediated keratinocyte ferroptosis promotes M1 polarization of macrophages to aggravate UVB-induced skin inflammation

Autophagy participates in the regulation of ferroptosis. Among numerous autophagy-related genes (ATGs), ATG5 plays a pivotal role in ferroptosis. However, how ATG5-mediated ferroptosis functions in UVB-induced skin inflammation is still unclear. In this study, we unveil that the core ferroptosis inhibitor GPX4 is significantly decreased in human skin tissue exposed to sunlight. We report that ATG5 deletion in mouse keratinocytes strongly protects against UVB-induced keratinocyte ferroptosis and skin inflammation. Mechanistically, ATG5 promotes the autophagy-dependent degradation of GPX4 in UVB-exposed keratinocytes, which leads to UVB-induced keratinocyte ferroptosis. Furthermore, we find that IFN-γ secreted by ferroptotic keratinocytes facilitates the M1 polarization of macrophages, which results in the exacerbation of UVB-induced skin inflammation. Together, our data indicate that ATG5 exacerbates UVB-induced keratinocyte ferroptosis in the epidermis, which subsequently gives rise to the secretion of IFN-γ and M1 polarization. Our study provides novel evidence that targeting ATG5 may serve as a potential therapeutic strategy for the amelioration of UVB-caused skin damage.

Chondroitin Sulfate-Modified Hydroxyapatite for Caspase-1 Activated Induced Pyroptosis through Ca Overload/ER Stress/STING/IRF3 Pathway in Colorectal Cancer

Immune checkpoint inhibitors, are the fourth most common therapeutic tool after surgery, chemotherapy, and radiotherapy for colorectal cancer (CRC). However, only a small proportion (≈5%) of CRC patients, those with "hot" (immuno-activated) tumors, benefit from the therapy. Pyroptosis, an innovative form of programmed cell death, is a potentially effective means to mediate a "cold" to "hot" transformation of the tumor microenvironment (TME). Calcium-releasing hydroxyapatite (HAP) nanoparticles (NPs) trigger calcium overload and pyroptosis in tumor cells. However, current limitations of these nanomedicines, such as poor tumor-targeting capabilities and insufficient calcium (Ca) ion release, limit their application. In this study, chondroitin sulfate (CS) is used to target tumors via binding to CD44 receptors and kaempferol (KAE) is used as a Ca homeostasis disruptor to construct CS-HAP@KAE NPs that function as pyroptosis inducers in CRC cells. CS-HAP@KAE NPs bind to the tumor cell membrane, HAP released Ca in response to the acidic environment of the TME, and kaempferol (KAE) enhances the influx of extracellular Ca, resulting in intracellular Ca overload and pyroptosis. This is associated with excessive endoplasmic reticulum stress triggered activation of the stimulator of interferon genes/interferon regulatory factor 3 pathway, ultimately transforming the TME from "cold" to "hot".

Constructing an immune-related prognostic signature for predicting prognosis and immune response in hepatocellular carcinoma

Background

Currently, there are few studies on immune-related prognostic analysis of hepatocellular carcinoma (HCC). Our aim was to establish an immune-correlated prognostic model for HCC.

Methods

Immune-associated cells were obtained from the scRNA-seq dataset (GSE149614) of HCC. Differentially expressed genes between normal and tumor cells from immune-associated cells and the immune-related genes from the ImmPort database were used to identify immune-related differentially expressed genes (IRDEGs). Subsequently, the risk model was established in the TCGA-LIHC cohort (n = 438) from the Cancer Genome Atlas (TCGA) database by using Kaplan-Meier (K-M) survival curve, univariate/multivariate Cox regression analysis. Subsequently, we further analyzed tumor immune microenvironment characteristics, somatic mutation, immune checkpoint and its ligand expression levels between high- and low-risk groups, as well as drug sensitivity prediction. ICGC cohort was set as the validation cohort. TCGA-LIHC cohort and three independent the Gene Expression Omnibus (GEO) datasets (GSE54236, GSE14520, and GSE64041) was used to verify IRDEGs expression, as well as PCR assays using clinical samples.

Results

The IRDEGs was composed of 4 genes, namely B2M, SPP1, PPIA, and HRG. The 438 HCC patients were divided into high- and low-risk group. The high-risk group was associated with poor prognosis, including higher T stage, advanced pathological stages, less immune cell infiltration, higher TP53 mutation rate, the high expression of CTLA4 and HAVCR2. Besides, high-risk populations benefit from most chemotherapy drugs. Similarly, the performance of the risk model was validated in the ICGC. All four datasets (TCGA-LIHC cohort, GSE54236, GSE14520, and GSE64041) and clinical q-PCR results demonstrated that, compared with normal samples, the expressions of B2M and HRG were lower in tumor samples, and the expression of SPP1 was higher.

Conclusion

In summary, the immune-related prognostic signature had a good predictive performance on prognosis and immunotherapy for HCC patients.

Biological impact and therapeutic implication of tumor-associated macrophages in hepatocellular carcinoma

The tumor microenvironment is a complex space comprised of normal, cancer and immune cells. The macrophages are considered as the most abundant immune cells in tumor microenvironment and their function in tumorigenesis is interesting. Macrophages can be present as M1 and M2 polarization that show anti-cancer and oncogenic activities, respectively. Tumor-associated macrophages (TAMs) mainly have M2 polarization and they increase tumorigenesis due to secretion of factors, cytokines and affecting molecular pathways. Hepatocellular carcinoma (HCC) is among predominant tumors of liver that in spite of understanding its pathogenesis, the role of tumor microenvironment in its progression still requires more attention. The presence of TAMs in HCC causes an increase in growth and invasion of HCC cells and one of the reasons is induction of glycolysis that such metabolic reprogramming makes HCC distinct from normal cells and promotes its malignancy. Since M2 polarization of TAMs stimulates tumorigenesis in HCC, molecular networks regulating M2 to M1 conversion have been highlighted and moreover, drugs and compounds with the ability of targeting TAMs and suppressing their M2 phenotypes or at least their tumorigenesis activity have been utilized. TAMs increase aggressive behavior and biological functions of HCC cells that can result in development of therapy resistance. Macrophages can provide cell-cell communication in HCC by secreting exosomes having various types of biomolecules that transfer among cells and change their activity. Finally, non-coding RNA transcripts can mainly affect polarization of TAMs in HCC.

Modified mesenchymal stromal cells by in vitro transcribed mRNA: a therapeutic strategy for hepatocellular carcinoma

BACKGROUND

Mesenchymal stromal cells (MSCs) tropism for tumours allows their use as carriers of antitumoural factors and in vitro transcribed mRNA (IVT mRNA) is a promising tool for effective transient expression without insertional mutagenesis risk. Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a cytokine with antitumor properties by stimulating the specific immune response. The aim of this work was to generate modified MSCs by IVT mRNA transfection to overexpress GM-CSF and determine their therapeutic effect alone or in combination with doxorubicin (Dox) in a murine model of hepatocellular carcinoma (HCC).

METHODS

DsRed or GM-CSF IVT mRNAs were generated from a cDNA template designed with specific primers followed by reverse transcription. Lipofectamine was used to transfect MSCs with DsRed (MSC/DsRed) or GM-CSF IVT mRNA (MSC/GM-CSF). Gene expression and cell surface markers were determined by flow cytometry. GM-CSF secretion was determined by ELISA. For in vitro experiments, the J774 macrophage line and bone marrow monocytes from mice were used to test GM-CSF function. An HCC model was developed by subcutaneous inoculation (s.c.) of Hepa129 cells into C3H/HeN mice. After s.c. injection of MSC/GM-CSF, Dox, or their combination, tumour size and mouse survival were evaluated. Tumour samples were collected for mRNA analysis and flow cytometry.

RESULTS

DsRed expression by MSCs was observed from 2 h to 15 days after IVT mRNA transfection. Tumour growth remained unaltered after the administration of DsRed-expressing MSCs in a murine model of HCC and MSCs expressing GM-CSF maintained their phenotypic characteristic and migration capability. GM-CSF secreted by modified MSCs induced the differentiation of murine monocytes to dendritic cells and promoted a proinflammatory phenotype in the J774 macrophage cell line. In vivo, MSC/GM-CSF in combination with Dox strongly reduced HCC tumour growth in C3H/HeN mice and extended mouse survival in comparison with individual treatments. In addition, the tumours in the MSC/GM-CSF + Dox treated group exhibited elevated expression of proinflammatory genes and increased infiltration of CD8 + T cells and macrophages.

CONCLUSIONS

Our results showed that IVT mRNA transfection is a suitable strategy for obtaining modified MSCs for therapeutic purposes. MSC/GM-CSF in combination with low doses of Dox led to a synergistic effect by increasing the proinflammatory tumour microenvironment, enhancing the antitumoural response in HCC.

Using a pan-cancer atlas to investigate tumour associated macrophages as regulators of immunotherapy response

The paradigm for macrophage characterization has evolved from the simple M1/M2 dichotomy to a more complex model that encompasses the broad spectrum of macrophage phenotypic diversity, due to differences in ontogeny and/or local stimuli. We currently lack an in-depth pan-cancer single cell RNA-seq (scRNAseq) atlas of tumour-associated macrophages (TAMs) that fully captures this complexity. In addition, an increased understanding of macrophage diversity could help to explain the variable responses of cancer patients to immunotherapy. Our atlas includes well established macrophage subsets as well as a number of additional ones. We associate macrophage composition with tumour phenotype and show macrophage subsets can vary between primary and metastatic tumours growing in sites like the liver. We also examine macrophage-T cell functional cross talk and identify two subsets of TAMs associated with T cell activation. Analysis of TAM signatures in a large cohort of immune checkpoint inhibitor-treated patients (CPI1000 + ) identify multiple TAM subsets associated with response, including the presence of a subset of TAMs that upregulate collagen-related genes. Finally, we demonstrate the utility of our data as a resource and reference atlas for mapping of novel macrophage datasets using projection. Overall, these advances represent an important step in both macrophage classification and overcoming resistance to immunotherapies in cancer.

Breaking the Barriers of Therapy Resistance: Harnessing Ferroptosis for Effective Hepatocellular Carcinoma Therapy

Ferroptosis is a type of cell death that relies on iron and is distinguished by the occurrence of lipid peroxidation and the buildup of reactive oxygen species. Ferroptosis has been demonstrated to have a significant impact on the advancement and resistance to treatment of hepatocellular carcinoma (HCC), thereby highlighting its potential as a viable therapeutic target. Ferroptosis was observed in HCC tissues in contrast to normal liver tissue. The inhibition of ferroptosis has been found to increase the viability of HCC cells and decrease their susceptibility to various anticancer therapies, including chemotherapy, radiotherapy, and immune checkpoint blockade. The administration of drugs that directly modulate ferroptosis regulators or induce excessive production of lipid-reactive oxygen species has demonstrated the potential to enhance the responsiveness of drug-resistant HCC cells to treatment. However, the precise mechanism underlying this phenomenon remains ambiguous. This review presents a comprehensive overview of the crucial role played by ferroptosis in enhancing the efficacy of treatment for hepatocellular carcinoma (HCC). The main aim of this study is to examine the feasibility of utilizing ferroptosis as a therapeutic approach to improve the efficacy of HCC treatment and overcome drug resistance.

Applications of single-cell multi-omics in liver cancer

Primary liver cancer, more specifically hepatocellular carcinoma (HCC), remains a significant global health problem associated with increasing incidence and mortality. Clinical, biological, and molecular heterogeneity are well-known hallmarks of cancer and HCC is considered one of the most heterogeneous tumour types, displaying substantial inter-patient, intertumoural and intratumoural variability. This heterogeneity plays a pivotal role in hepatocarcinogenesis, metastasis, relapse and drug response or resistance. Unimodal single-cell sequencing techniques have already revolutionised our understanding of the different layers of molecular hierarchy in the tumour microenvironment of HCC. By highlighting the cellular heterogeneity and the intricate interactions among cancer, immune and stromal cells before and during treatment, these techniques have contributed to a deeper comprehension of tumour clonality, hematogenous spreading and the mechanisms of action of immune checkpoint inhibitors. However, major questions remain to be elucidated, with the identification of biomarkers predicting response or resistance to immunotherapy-based regimens representing an important unmet clinical need. Although the application of single-cell multi-omics in liver cancer research has been limited thus far, a revolution of individualised care for patients with HCC will only be possible by integrating various unimodal methods into multi-omics methodologies at the single-cell resolution. In this review, we will highlight the different established single-cell sequencing techniques and explore their biological and clinical impact on liver cancer research, while casting a glance at the future role of multi-omics in this dynamic and rapidly evolving field.

The engineered exosomes targeting ferroptosis: A novel approach to reverse immune checkpoint inhibitors resistance

Immune checkpoint inhibitors (ICIs) have been extensively used in immunological therapy primarily due to their ability to prolong patient survival. Although ICIs have achieved success in cancer treatment, the resistance of ICIs should not be overlooked. Ferroptosis is a newly found cell death mode characterized by the accumulation of reactive oxygen species (ROS), glutathione (GSH) depletion, and glutathione peroxidase 4 (GPX4) inactivation, which has been demonstrated to be beneficial to immunotherapy and combining ferroptosis and ICIs to exploit new immunotherapies may reverse ICIs resistance. Exosomes act as mediators in cell-to-cell communication that may regulate ferroptosis to influence immunotherapy through the secretion of biological molecules. Thus, utilizing exosomes to target ferroptosis has opened up exciting possibilities for reversing ICIs resistance. In this review, we summarize the mechanisms of ferroptosis improving ICIs therapy and how exosomes regulate ferroptosis through adjusting iron metabolism, blocking the ROS accumulation, controlling ferroptosis defense systems, and influencing classic signaling pathways and how engineered exosomes target ferroptosis and improve ICIs efficiency.

Targeting MS4A4A: A novel pathway to improve immunotherapy responses in glioblastoma

INTRODUCTION

Glioblastoma (GBM) remains a challenging brain tumor to treat, with limited response to PD-1 immunotherapy due to tumor-associated macrophages (TAMs), specifically the M2 phenotype. This study explores the potential of MS4A4A (membrane spanning four domains, subfamily A, member 4A) inhibition in driving M2 macrophage polarization toward the M1 phenotype via the ferroptosis pathway to enhance the effectiveness of immunotherapy in GBM.

METHODS

Single-cell RNA sequencing and spatial transcriptomic analyses were employed to characterize M2 macrophages and MS4A4A expression in GBM. In vitro studies utilizing TAM cultures, flow cytometry, and western blot validations were conducted to assess the impact of MS4A4A on the tumor immune microenvironment and M2 macrophage polarization. In vivo models, including subcutaneous and orthotopic transplantation in mice, were utilized to evaluate the effects of MS4A4A knockout and combined immune checkpoint blockade (ICB) therapy on tumor growth and response to PD-1 immunotherapy.

RESULTS

Distinct subsets of GBM-associated macrophages were identified, with spatial distribution in tumor tissue elucidated. In vivo experiments demonstrated that inhibiting MS4A4A and combining ICB therapy effectively inhibited tumor growth, reshaped the tumor immune microenvironment by reducing M2 TAM infiltration and enhancing CD8+ T-cell infiltration, ultimately leading to complete tumor eradication.

CONCLUSION

MS4A4A inhibition shows promise in converting M2 macrophages to M1 phenotype via ferroptosis, decreasing M2-TAM infiltration, and enhancing GBM response to PD-1 immunotherapy. These findings offer a novel approach to developing more effective immunotherapeutic strategies for GBM.

Current Progress of Ferroptosis Study in Hepatocellular Carcinoma

Ferroptosis, an emerging type of programmed cell death, is initiated by iron-dependent and excessive ROS-mediated lipid peroxidation, which eventually leads to plasma membrane rupture and cell death. Many canonical signalling pathways and biological processes are involved in ferroptosis. Furthermore, cancer cells are more susceptible to ferroptosis due to the high load of ROS and unique metabolic characteristics, including iron requirements. Recent investigations have revealed that ferroptosis plays a crucial role in the progression of tumours, especially HCC. Specifically, the induction of ferroptosis can not only inhibit the growth of hepatoma cells, thereby reversing tumorigenesis, but also improves the efficacy of immunotherapy and enhances the antitumour immune response. Therefore, triggering ferroptosis has become a new therapeutic strategy for cancer therapy. In this review, we summarize the characteristics of ferroptosis based on its underlying mechanism and role in HCC and provide possible therapeutic applications.

Liver cancer from the perspective of single-cell sequencing: a review combined with bibliometric analysis

BACKGROUND

Liver cancer (LC) is a prevalent malignancy and a leading cause of cancer-related mortality worldwide. Extensive research has been conducted to enhance patient outcomes and develop effective prevention strategies, ranging from molecular mechanisms to clinical interventions. Single-cell sequencing, as a novel bioanalysis technology, has significantly contributed to the understanding of the global cognition and dynamic changes in liver cancer. However, there is a lack of bibliometric analysis in this specific research area. Therefore, the objective of this study is to provide a comprehensive overview of the knowledge structure and research hotspots in the field of single-cell sequencing in liver cancer research through the use of bibliometrics.

METHOD

Publications related to the application of single-cell sequencing technology to liver cancer research as of December 31, 2023, were searched on the web of science core collection (WoSCC) database. VOSviewers, CiteSpace, and R package "bibliometrix" were used to conduct this bibliometric analysis.

RESULTS

A total of 331 publications from 34 countries, primarily led by China and the United States, were included in this study. The research focuses on the application of single cell sequencing technology to liver cancer, and the number of related publications has been increasing year by year. The main research institutions involved in this field are Fudan University, Sun Yat-Sen University, and the Chinese Academy of Sciences. Frontiers in Immunology and Nature Communications is the most popular journal in this field, while Cell is the most frequently co-cited journal. These publications are authored by 2799 individuals, with Fan Jia and Zhou Jian having the most published papers, and Llovet Jm being the most frequently co-cited author. The use of single cell sequencing to explore the immune microenvironment of liver cancer, as well as its implications in immunotherapy and chemotherapy, remains the central focus of this field. The emerging research hotspots are characterized by keywords such as 'Gene-Expression', 'Prognosis', 'Tumor Heterogeneity', 'Immunoregulation', and 'Tumor Immune Microenvironment'.

CONCLUSION

This is the first bibliometric study that comprehensively summarizes the research trends and developments on the application of single cell sequencing in liver cancer. The study identifies recent research frontiers and hot directions, providing a valuable reference for researchers exploring the landscape of liver cancer, understanding the composition of the immune microenvironment, and utilizing single-cell sequencing technology to guide and enhance the prognosis of liver cancer patients.

Advances in integrating single-cell sequencing data to unravel the mechanism of ferroptosis in cancer

Ferroptosis, a commonly observed type of programmed cell death caused by abnormal metabolic and biochemical mechanisms, is frequently triggered by cellular stress. The occurrence of ferroptosis is predominantly linked to pathophysiological conditions due to the substantial impact of various metabolic pathways, including fatty acid metabolism and iron regulation, on cellular reactions to lipid peroxidation and ferroptosis. This mode of cell death serves as a fundamental factor in the development of numerous diseases, thereby presenting a range of therapeutic targets. Single-cell sequencing technology provides insights into the cellular and molecular characteristics of individual cells, as opposed to bulk sequencing, which provides data in a more generalized manner. Single-cell sequencing has found extensive application in the field of cancer research. This paper reviews the progress made in ferroptosis-associated cancer research using single-cell sequencing, including ferroptosis-associated pathways, immune checkpoints, biomarkers, and the identification of cell clusters associated with ferroptosis in tumors. In general, the utilization of single-cell sequencing technology has the potential to contribute significantly to the investigation of the mechanistic regulatory pathways linked to ferroptosis. Moreover, it can shed light on the intricate connection between ferroptosis and cancer. This technology holds great promise in advancing tumor-wide diagnosis, targeted therapy, and prognosis prediction.

Macrophage Perspectives in Liver Diseases: Programmed Death, Related Biomarkers, and Targeted Therapy

Macrophages, as important immune cells of the organism, are involved in maintaining intrahepatic microenvironmental homeostasis and can undergo rapid phenotypic changes in the injured or recovering liver. In recent years, the crucial role of macrophage-programmed cell death in the development and regression of liver diseases has become a research hotspot. Moreover, macrophage-targeted therapeutic strategies are emerging in both preclinical and clinical studies. Given the macrophages' vital role in complex organismal environments, there is tremendous academic interest in developing novel therapeutic strategies that target these cells. This review provides an overview of the characteristics and interactions between macrophage polarization, programmed cell death, related biomarkers, and macrophage-targeted therapies. It aims to deepen the understanding of macrophage immunomodulation and molecular mechanisms and to provide a basis for the treatment of macrophage-associated liver diseases.

A novel single-cell model reveals ferroptosis-associated biomarkers for individualized therapy and prognostic prediction in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is a prevalent malignancy with a pressing need for improved therapeutic response and prognosis prediction. This study delves into a novel predictive model related to ferroptosis, a regulated cell death mechanism disrupting metabolic processes.

RESULTS

Single-cell sequencing data analysis identified subpopulations of HCC cells exhibiting activated ferroptosis and distinct gene expression patterns compared to normal tissues. Utilizing the LASSO-Cox algorithm, we constructed a model with 10 single-cell biomarkers associated with ferroptosis, namely STMN1, S100A10, FABP5, CAPG, RGCC, ENO1, ANXA5, UTRN, CXCR3, and ITM2A. Comprehensive analyses using these biomarkers revealed variations in immune infiltration, tumor mutation burden, drug sensitivity, and biological functional profiles between risk groups. Specific associations were established between particular immune cell subtypes and certain gene expression patterns. Treatment response analyses indicated potential benefits from anti-tumor immune therapy for the low-risk group and chemotherapy advantages for the high-risk group.

CONCLUSIONS

The integration of this single-cell level model with clinicopathological features enabled accurate overall survival prediction and effective risk stratification in HCC patients. Our findings illuminate the potential of ferroptosis-related genes in tailoring therapy and prognosis prediction for HCC, offering novel insights into the intricate interplay among ferroptosis, immune response, and HCC progression.

Integrated Analysis of scRNA-Seq and Bulk RNA-Seq Reveals Metabolic Reprogramming of Liver Cancer and Establishes a Prognostic Risk Model

Liver cancer manifests as a profoundly heterogeneous malignancy, posing significant challenges in terms of both therapeutic intervention and prognostic evaluation. Given that the liver is the largest metabolic organ, a prognostic risk model grounded in single-cell transcriptome analysis and a metabolic perspective can facilitate precise prevention and treatment strategies for liver cancer. Hence, we identified 11 cell types in a scRNA-seq profile comprising 105,829 cells and found that the metabolic activity of malignant cells increased significantly. Subsequently, a prognostic risk model incorporating tumor heterogeneity, cell interactions, tumor cell metabolism, and differentially expressed genes was established based on eight genes; this model can accurately distinguish the survival outcomes of liver cancer patients and predict the response to immunotherapy. Analyzing the immune status and drug sensitivity of the high- and low-risk groups identified by the model revealed that the high-risk group had more active immune cell status and greater expression of immune checkpoints, indicating potential risks associated with liver cancer-targeted drugs. In summary, this study provides direct evidence for the stratification and precise treatment of liver cancer patients, and is an important step in establishing reliable predictors of treatment efficacy in liver cancer patients.

Ferroptosis: principles and significance in health and disease

Ferroptosis, an iron-dependent form of cell death characterized by uncontrolled lipid peroxidation, is governed by molecular networks involving diverse molecules and organelles. Since its recognition as a non-apoptotic cell death pathway in 2012, ferroptosis has emerged as a crucial mechanism in numerous physiological and pathological contexts, leading to significant therapeutic advancements across a wide range of diseases. This review summarizes the fundamental molecular mechanisms and regulatory pathways underlying ferroptosis, including both GPX4-dependent and -independent antioxidant mechanisms. Additionally, we examine the involvement of ferroptosis in various pathological conditions, including cancer, neurodegenerative diseases, sepsis, ischemia-reperfusion injury, autoimmune disorders, and metabolic disorders. Specifically, we explore the role of ferroptosis in response to chemotherapy, radiotherapy, immunotherapy, nanotherapy, and targeted therapy. Furthermore, we discuss pharmacological strategies for modulating ferroptosis and potential biomarkers for monitoring this process. Lastly, we elucidate the interplay between ferroptosis and other forms of regulated cell death. Such insights hold promise for advancing our understanding of ferroptosis in the context of human health and disease.

Proteomic, single-cell and bulk transcriptomic analysis of plasma and tumor tissues unveil core proteins in response to anti-PD-L1 immunotherapy in triple negative breast cancer

BACKGROUND

Anti-PD-1/PD-L1 treatment has achieved durable responses in TNBC patients, whereas a fraction of them showed non-sensitivity to the treatment and the mechanism is still unclear.

METHODS

Pre- and post-treatment plasma samples from triple negative breast cancer (TNBC) patients treated with immunotherapy were measured by tandem mass tag (TMT) mass spectrometry. Public proteome data of lung cancer and melanoma treated with immunotherapy were employed to validate the findings. Blood and tissue single-cell RNA sequencing (scRNA-seq) data of TNBC patients treated with or without immunotherapy were analyzed to identify the derivations of plasma proteins. RNA-seq data from IMvigor210 and other cancer types were used to validate plasma proteins in predicting response to immunotherapy.

RESULTS

A random forest model constructed by FAP, LRG1, LBP and COMP could well predict the response to immunotherapy. The activation of complement cascade was observed in responders, whereas FAP and COMP showed a higher abundance in non-responders and negative correlated with the activation of complements. scRNA-seq and bulk RNA-seq analysis suggested that FAP, COMP and complements were derived from fibroblasts of tumor tissues.

CONCLUSIONS

We constructe an effective plasma proteomic model in predicting response to immunotherapy, and find that FAP+ and COMP+ fibroblasts are potential targets for reversing immunotherapy resistance.

The integrate profiling of single-cell and spatial transcriptome RNA-seq reveals tumor heterogeneity, therapeutic targets, and prognostic subtypes in ccRCC

Clear-cell renal cell carcinoma (ccRCC) is the most common type of RCC; however, the intratumoral heterogeneity in ccRCC remains unclear. We first identified markers and biological features of each cell cluster using bioinformatics analysis based on single-cell and spatial transcriptome RNA-sequencing data. We found that gene copy number loss on chromosome 3p and amplification on chromosome 5q were common features in ccRCC cells. Meanwhile, NNMT and HILPDA, which are associated with the response to hypoxia and metabolism, are potential therapeutic targets for ccRCC. In addition, CD8+ exhausted T cells (LAG3+ HAVCR2+), CD8+ proliferated T cells (STMN+), and M2-like macrophages (CD68+ CD163+ APOC1+), which are closely associated with immunosuppression, played vital roles in ccRCC occurrence and development. These results were further verified by whole exome sequencing, cell line and xenograft experiments, and immunofluorescence staining. Finally, we divide patients with ccRCC into three subtypes using unsupervised cluster analysis. and generated a classifier to reproduce these subtypes using the eXtreme Gradient Boosting algorithm. Our classifier can help clinicians evaluate prognosis and design personalized treatment strategies for ccRCC. In summary, our work provides a new perspective for understanding tumor heterogeneity and will aid in the design of antitumor therapeutic strategies for ccRCC.

Pan-Cancer Single-Cell and Spatial-Resolved Profiling Reveals the Immunosuppressive Role of APOE+ Macrophages in Immune Checkpoint Inhibitor Therapy

The heterogeneity of macrophages influences the response to immune checkpoint inhibitor (ICI) therapy. However, few studies explore the impact of APOE+ macrophages on ICI therapy using single-cell RNA sequencing (scRNA-seq) and machine learning methods. The scRNA-seq and bulk RNA-seq data are Integrated to construct an M.Sig model for predicting ICI response based on the distinct molecular signatures of macrophage and machine learning algorithms. Comprehensive single-cell analysis as well as in vivo and in vitro experiments are applied to explore the potential mechanisms of the APOE+ macrophage in affecting ICI response. The M.Sig model shows clear advantages in predicting the efficacy and prognosis of ICI therapy in pan-cancer patients. The proportion of APOE+ macrophages is higher in ICI non-responders of triple-negative breast cancer compared with responders, and the interaction and longer distance between APOE+ macrophages and CD8+ exhausted T (Tex) cells affecting ICI response is confirmed by multiplex immunohistochemistry. In a 4T1 tumor-bearing mice model, the APOE inhibitor combined with ICI treatment shows the best efficacy. The M.Sig model using real-world immunotherapy data accurately predicts the ICI response of pan-cancer, which may be associated with the interaction between APOE+ macrophages and CD8+ Tex cells.

Ferroptosis, pyroptosis and necroptosis in hepatocellular carcinoma immunotherapy: Mechanisms and immunologic landscape (Review)

Hepatocellular carcinoma (HCC), one of the leading causes of cancer‑related mortality worldwide, is challenging to identify in its early stages and prone to metastasis, and the prognosis of patients with this disease is poor. Treatment options for HCC are limited, with even radical treatments being associated with a risk of recurrence or transformation in the short term. Furthermore, the multi‑tyrosine kinase inhibitors approved for first‑line therapy have marked drawbacks, including drug resistance and side effects. The rise and breakthrough of immune checkpoint inhibitors (ICIs) have provided a novel direction for HCC immunotherapy but these have the drawback of low response rates. Since avoiding apoptosis is a universal feature of cancer, the induction of non‑apoptotic regulatory cell death (NARCD) is a novel strategy for HCC immunotherapy. At present, NARCD pathways, including ferroptosis, pyroptosis and necroptosis, are novel potential forms of immunogenic cell death, which have synergistic effects with antitumor immunity, transforming immune 'cold' tumors into immune 'hot' tumors and exerting antitumor effects. Therefore, these pathways may be targeted as a novel treatment strategy for HCC. In the present review, the roles of ferroptosis, pyroptosis and necroptosis in antitumor immunity in HCC are discussed, and the relevant targets and signaling pathways, and the current status of combined therapy with ICIs are summarized. The prospects of targeting ferroptosis, pyroptosis and necroptosis in HCC immunotherapy are also considered.

Ferroptosis and hepatocellular carcinoma: the emerging role of lncRNAs

Hepatocellular carcinoma is the most common form of primary liver cancer and poses a significant challenge to the medical community because of its high mortality rate. In recent years, ferroptosis, a unique form of cell death, has garnered widespread attention. Ferroptosis, which is characterized by iron-dependent lipid peroxidation and mitochondrial alterations, is closely associated with the pathological processes of various diseases, including hepatocellular carcinoma. Long non-coding RNAs (lncRNAs), are a type of functional RNA, and play crucial regulatory roles in a variety of biological processes. In this manuscript, we review the regulatory roles of lncRNAs in the key aspects of ferroptosis, and summarize the research progress on ferroptosis-related lncRNAs in hepatocellular carcinoma.

Immunosuppressive tumor microenvironment and immunotherapy of hepatocellular carcinoma: current status and prospectives

Hepatocellular carcinoma (HCC) is a major health concern worldwide, with limited therapeutic options and poor prognosis. In recent years, immunotherapies such as immune checkpoint inhibitors (ICIs) have made great progress in the systemic treatment of HCC. The combination treatments based on ICIs have been the major trend in this area. Recently, dual immune checkpoint blockade with durvalumab plus tremelimumab has also emerged as an effective treatment for advanced HCC. However, the majority of HCC patients obtain limited benefits. Understanding the immunological rationale and exploring novel ways to improve the efficacy of immunotherapy has drawn much attention. In this review, we summarize the latest progress in this area, the ongoing clinical trials of immune-based combination therapies, as well as novel immunotherapy strategies such as chimeric antigen receptor T cells, personalized neoantigen vaccines, oncolytic viruses, and bispecific antibodies.

Macrophage diversity in human cancers: New insight provided by single-cell resolution and spatial context

M1/M2 paradigm of macrophage plasticity has existed for decades. Now it becomes clear that this dichotomy doesn't adequately reflect the diversity of macrophage phenotypes in tumor microenvironment (TME). Tumor-associated macrophages (TAMs) are a major population of innate immune cells in the TME that promotes tumor cell proliferation, angiogenesis and lymphangiogenesis, invasion and metastatic niche formation, as well as response to anti-tumor therapy. However, the fundamental restriction in therapeutic TAM targeting is the limited knowledge about the specific TAM states in distinct human cancer types. Here we summarized the results of the most recent studies that use advanced technologies (e.g. single-cell RNA sequencing and spatial transcriptomics) allowing to decipher novel functional subsets of TAMs in numerous human cancers. The transcriptomic profiles of these TAM subsets and their clinical significance were described. We emphasized the characteristics of specific TAM subpopulations - TREM2+, SPP1+, MARCO+, FOLR2+, SIGLEC1+, APOC1+, C1QC+, and others, which have been most extensively characterized in several cancers, and are associated with cancer prognosis. Spatial transcriptomics technologies defined specific spatial interactions between TAMs and other cell types, especially fibroblasts, in tumors. Spatial transcriptomics methods were also applied to identify markers of immunotherapy response, which are expressed by macrophages or in the macrophage-abundant regions. We highlighted the perspectives for novel techniques that utilize spatial and single cell resolution in investigating new ligand-receptor interactions for effective immunotherapy based on TAM-targeting.

Mitochondrial-Targeted CS@KET/P780 Nanoplatform for Site-Specific Delivery and High-Efficiency Cancer Immunotherapy in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a form of malignancy with limited curative options available. To improve therapeutic outcomes, it is imperative to develop novel, potent therapeutic modalities. Ketoconazole (KET) has shown excellent therapeutic efficacy against HCC by eliciting apoptosis. However, its limited water solubility hampers its application in clinical treatment. Herein, a mitochondria-targeted chemo-photodynamic nanoplatform, CS@KET/P780 NPs, is designed using a nanoprecipitation strategy by integrating a newly synthesized mitochondria-targeted photosensitizer (P780) and chemotherapeutic agent KET coated with chondroitin sulfate (CS) to amplify HCC therapy. In this nanoplatform, CS confers tumor-targeted and subsequently pH-responsive drug delivery behavior by binding to glycoprotein CD44, leading to the release of P780 and KET. Mechanistically, following laser irradiation, P780 targets and destroys mitochondrial integrity, thus inducing apoptosis through the enhancement of reactive oxygen species (ROS) buildup. Meanwhile, KET-induced apoptosis synergistically enhances the anticancer effect of P780. In addition, tumor cells undergoing apoptosis can trigger immunogenic cell death (ICD) and a longer-term antitumor response by releasing tumor-associated antigens (TAAs) and damage-associated molecular patterns (DAMPs), which together contribute to improved therapeutic outcomes in HCC. Taken together, CS@KET/P780 NPs improve the bioavailability of KET and exhibit excellent therapeutic efficacy against HCC by exerting chemophototherapy and antitumor immunity.

Targeting the lipid metabolic reprogramming of tumor-associated macrophages: A novel insight into cancer immunotherapy

BACKGROUND

Tumor-associated macrophages, as the major immunocytes in solid tumors, show divided loyalty and remarkable plasticity in tumorigenesis. Once the M2-to-M1 repolarization is achieved, they could be switched from the supporters for tumor development into the guardians for host immunity. Meanwhile, Lipid metabolic reprogramming is demonstrated to be one of the most important hallmarks of tumor-associated macrophages, which plays a decisive role in regulating their phenotypes and functions to promote tumorigenesis and immunotherapy resistance. Therefore, targeting the lipid metabolism of TAMs may provide a new direction for anti-tumor strategies.

CONCLUSION

In this review, we first summarized the origins, classifications and general lipid metabolic process of TAMs. Then we discussed the currently available drugs and interventions that target lipid metabolic disorders of TAMs, including those targeting lipid uptake, efflux, lipolysis, FAO and lipid peroxidation. Besides, based on the recent research status, we summarized the present challenges for this cancer immunotherapy, including the precise drug delivery system, the lipid metabolic heterogeneity, and the intricate lipid metabolic interactions in the TME, and we also proposed corresponding possible solutions. Collectively, we hope this review will give researchers a better understanding of the lipid metabolism of TAMs and lead to the development of corresponding anti-tumor therapies in the future.

Fibroblast growth factor inhibition by molecular-targeted agents mitigates immunosuppressive tissue microenvironment in hepatocellular carcinoma

BACKGROUND & AIMS

Combination immunotherapy refers to the use of immune checkpoint inhibitors (ICI) and molecular-targeted agents (MTA), which have recently been approved for the treatment of advanced hepatocellular carcinoma (HCC). Owing to its relatively low antitumor effect (up to 30%), sequential therapy following ICIs treatment is required in patients with HCC. This study aimed to determine the impact of MTAs on the tumor immune microenvironment (TIME).

METHODS

We established immune syngeneic orthotopic HCC mouse models using Hep-55.1C and Hep-53.4, and treated them with MTAs (lenvatinib, sorafenib, regorafenib, cabozantinib, and DC101 as anti-vascular endothelial growth factor receptor-2 antibodies, and AZD4547 as a fibroblast growth factor receptor (FGFR)-1/2/3/4 inhibitor) for 2 weeks. Subsequently, alterations in the TIME caused by MTAs were evaluated using immunohistochemistry (antibodies for CD3, CD8, Foxp3, Granzyme B, Arginase-1, NK1.1, F4/80, CD11c, PD-1, and PD-L1). We conducted RNA-seq analysis using lenvatinib- and AZD4547-treated tumors. To confirm the clinical relevance of these findings, we analyzed the transcriptome data of human HCC cells (MHCC-97H) treated with various concentrations of lenvatinib for 24 h using RNA-seq data from the Gene Expression Omnibus database.

RESULTS

The number of Foxp3- and F4/80-positive cells in the TIME was decreased in many MTAs. Cabozantinib increased the numbers in NK1.1-, Granzyme B, and CD11c-positive cells. Lenvatinib and AZD4547 increased the number of CD8, Granzyme B, and PD-L1-positive cells. Gene ontology enrichment analysis revealed that lipid metabolism-related genes were downregulated by lenvatinib and AZD4547. In total, 161 genes downregulated by FGFR inhibition in rodent models overlapped with those downregulated by lenvatinib in human HCC cells.

CONCLUSIONS

In this study, we showed that cabozantinib activated the innate immune system, and lenvatinib and AZD4547, which commonly inhibit FGFR signaling, altered TIME to a hot immune state by downregulating lipid metabolism-related genes. These findings support the therapeutic use of combination immunotherapies.

M1 macrophage-related gene model for NSCLC immunotherapy response prediction

Patients diagnosed with non-small cell lung cancer (NSCLC) have a limited lifespan and exhibit poor immunotherapy outcomes. M1 macrophages have been found to be essential for antitumor immunity. This study aims to develop an immunotherapy response evaluation model for NSCLC patients based on transcription. RNA sequencing profiles of 254 advanced-stage NSCLC patients treated with immunotherapy are downloaded from the POPLAR and OAK projects. Immune cell infiltration in NSCLC patients is examined, and thereafter, different coexpressed genes are identified. Next, the impact of M1 macrophage-related genes on the prognosis of NSCLC patients is investigated. Six M1 macrophage coexpressed genes, namely, NKX2-1, CD8A , SFTA3, IL2RB, IDO1, and CXCL9, exhibit a strong association with the prognosis of NSCLC and serve as effective predictors for immunotherapy response. A response model is constructed using a Cox regression model and Lasso Cox regression analysis. The M1 genes are validated in our TD-FOREKNOW NSCLC clinical trial by RT-qPCR. The response model shows excellent immunotherapy response prediction and prognosis evaluation value in advanced-stage NSCLC. This model can effectively predict advanced NSCLC prognosis and aid in identifying patients who could benefit from customized immunotherapy as well as sensitive drugs.

APOC1 is a prognostic biomarker associated with M2 macrophages in ovarian cancer

BACKGROUND

Recent studies have demonstrated that APOC1 is associated with cancer progression, exerting cancer-promoting and immune infiltration-promoting effects. Nevertheless, there is currently no report on the presence of APOC1 in ovarian cancer (OV).

METHOD

In this study, we conducted data analysis using the GEO and TCGA databases. We conducted a thorough bioinformatics analysis to investigate the function of APOC1 in OV, utilizing various platforms including cBioPortal, STRING, GeneMANIA, LinkedOmics, GSCALite, TIMER, and CellMarker. Additionally, we performed immunohistochemical staining on tissue microarrays and conducted in vitro cellular assays to validate our findings.

RESULT

Our findings reveal that APOC1 expression is significantly upregulated in OV compared to normal tissues. Importantly, patients with high APOC1 levels show a significantly poorer prognosis. Furthermore, our study demonstrated that APOC1 exerted a crucial function in promoting the capacity of ovarian cancer cells to proliferate, migrate, and invade. Additionally, we have identified that genes co-expressed with APOC1 are primarily associated with adaptive immune responses. Notably, the levels of APOC1 in OV exhibit a correlation with the presence of M2 Tumor-associated Macrophages (TAMs).

CONCLUSION

APOC1 emerges as a promising prognostic biomarker for OV and exhibits a significant association with M2 TAMs in OV.

The dance of macrophage death: the interplay between the inevitable and the microenvironment

Macrophages are highly plastic cells ubiquitous in various tissues, where they perform diverse functions. They participate in the response to pathogen invasion and inflammation resolution following the immune response, as well as the maintenance of homeostasis and proper tissue functions. Macrophages are generally considered long-lived cells with relatively strong resistance to numerous cytotoxic factors. On the other hand, their death seems to be one of the principal mechanisms by which macrophages perform their physiological functions or can contribute to the development of certain diseases. In this review, we scrutinize three distinct pro-inflammatory programmed cell death pathways - pyroptosis, necroptosis, and ferroptosis - occurring in macrophages under specific circumstances, and explain how these cells appear to undergo dynamic yet not always final changes before ultimately dying. We achieve that by examining the interconnectivity of these cell death types, which in macrophages seem to create a coordinated and flexible system responding to the microenvironment. Finally, we discuss the complexity and consequences of pyroptotic, necroptotic, and ferroptotic pathway induction in macrophages under two pathological conditions - atherosclerosis and cancer. We summarize damage-associated molecular patterns (DAMPs) along with other microenvironmental factors, macrophage polarization states, associated mechanisms as well as general outcomes, as such a comprehensive look at these correlations may point out the proper methodologies and potential therapeutic approaches.

Investigating the mechanisms of drug resistance and prognosis in ovarian cancer using single-cell RNA sequencing and bulk RNA sequencing

Ovarian cancer stands as a prevalent malignancy within the realm of gynecology, and the emergence of resistance to chemotherapeutic agents remains a pivotal impediment to both prognosis and treatment. Through a single-cell level investigation, we scrutinize the drug resistance and mitotic activity of the core tumor cells in ovarian cancer. Our study revisits the interrelationships and temporal trajectories of distinct epithelial cells (EPCs) subpopulations, while identifying genes associated with ovarian cancer prognosis. Notably, our findings establish a strong association between the drug resistance of EPCs and oxidative phosphorylation pathways. Subsequently, through subpopulation and temporal trajectory analysis, we confirm the intermediate position of EPCs subpopulation C0. Furthermore, we delve into the immunological functions and differentially expressed genes associated with the prognosis of C0, shedding light on the potential for constructing novel ovarian cancer prognosis models and identifying new therapeutic targets.