Targeted xCT-mediated Ferroptosis and Protumoral Polarization of Macrophages Is Effective against HCC and Enhances the Efficacy of the Anti-PD-1/L1 Response

Cellular Membrane Protein GRINA is Highly Expressed and Associated with Survival Outcomes in Liver Cancer Patients

OBJECTIVE

Hepatocellular carcinoma (HCC), a lethal cancer with high global mortality, may be targeted through ferroptosis, an iron-dependent form of cell death. Despite its potential, the prognostic value of ferroptosis in HCC is underexplored.

METHODS

Our study leveraged single-cell and bulk sequencing datasets to identify ferroptosis-related genes and developed a prognostic model via Cox and LASSO regression analyses. Survival and mutation analyses led to the creation of a nomogram for predicting patient prognosis. Furthermore, we investigated the role of GRINA, a ferroptosis-related gene, through functional assays, including cell proliferation, colony formation, and metastatic potential analyses. We also assessed mitochondrial abnormalities, intracellular iron, and ROS levels in GRINA-knockdown cells.

RESULTS

The developed ferroptosis-related model classified HCC patients into risk groups, revealing notable survival disparities. High-risk patients presented increased immune checkpoint gene expression. The nomogram revealed robust prognostic accuracy. Additionally, we found that GRINA suppression reduced HCC cell proliferation, colony formation, and metastatic potential. Cells with GRINA knockdown presented mitochondrial abnormalities and increased intracellular iron and ROS levels.

CONCLUSIONS

By analysing multiomics sequencing data, we established a connection between ferroptosis-related risk groups and the tumor immune microenvironment. These findings provide novel insights into the role of ferroptosis in HCC and suggest that GRINA inhibition is a potential therapeutic strategy, leading to mitochondrial damage and the induction of ferroptosis in HCC cell lines.

Development and validation of an Immune-related Gene-based model for predicting prognosis and immunotherapy outcomes in hepatocellular carcinoma patients

Predicting disease prognosis and the efficacy of immunotherapy presents a significant challenge in the treatment of hepatocellular carcinoma (HCC). By analyzing transcriptome sequencing data from 69 patients and identifying differentially expressed immune genes, a prognostic index named the immune-related gene prognostic index (IRGPI) was established by Lasso-Cox regression. The IRGPI, which consists of six key genes, was found to be a significant predictor of poor prognosis in patients with high IRGPI scores. The model's predictive accuracy was confirmed via receiver operating characteristic (ROC) curve analysis, with area under the curve (AUC) values of 0.85, 0.779, and 0.857 for 1-, 3-, and 5-year survival predictions, respectively. Additionally, patients with high IRGPI scores had increased levels of Treg cells and neutrophils, advanced tumor staging, microvascular invasion grading, and immune checkpoint expression. The IRGPI was also effective in predicting the efficacy of immunotherapy in the IMvigor210 dataset, demonstrating its potential as a valuable tool for assessing patient prognosis and guiding immunotherapy strategies in HCC.

CircTTC13 promotes sorafenib resistance in hepatocellular carcinoma through the inhibition of ferroptosis by targeting the miR-513a-5p/SLC7A11 axis

The high mortality rate from hepatocellular carcinoma (HCC) is due primarily to challenges in early diagnosis and the development of drug resistance in advanced stages. Many first-line chemotherapeutic drugs induce ferroptosis, a form of programmed cell death dependent on ferrous iron-mediated oxidative stress, suggesting that drug resistance and ensuing tumor progression may in part stem from reduced ferroptosis. Since circular RNAs (circRNAs) have been shown to influence tumor development, we examined whether specific circRNAs may regulate drug-induced ferroptosis in HCC. Through circRNA sequencing, we identified a novel hsa_circ_0000195 (circTTC13) that is overexpressed in HCC tissues. This overexpression is linked to higher tumor grade, more advanced tumor stage, decreased ferroptosis, and poorer overall survival. Overexpression of CircTTC13 in HCC cell lines and explant tumors was associated with increased proliferation rates, enhanced metastatic capacity, and resistance to sorafenib, while also inhibiting ferroptosis. Conversely, circTTC13 silencing reduced malignant characteristics and promoted ferroptosis. In silico analysis, luciferase assays, and fluorescence in situ hybridization collectively demonstrated that circTTC13 directly targets and reduces miR-513a-5p expression, which in turn leads to the upregulation of the negative ferroptosis regulator SLC7A11. Moreover, the inhibition of SLC7A11 mirrored the effect of circTTC13 knockdown, whereas ferroptosis inhibition mimicked the effect of circTTC13 overexpression. Both circTTC13 and SLC7A11 were highly expressed in drug-resistant HCC cells, and circTTC13 silencing induced ferroptosis and reversed sorafenib resistance in explant tumors. These findings identify circTTC13 as a critical driver of HCC progression and resistance to drug-induced ferroptosis via upregulation of SLC7A11. The cicTTC13/miR-513a-5p/SLC7A11 axis represents a potential therapeutic target for HCC.

Macrophage Ferroptotic Resistance Is Required for the Progression of Infantile Hemangioma

BACKGROUND

Ferroptosis is a programmed cell death caused by iron-dependent accumulation and cellular lipid peroxides, which is different from apoptosis and pyroptosis. This study investigated the possible effect of ferroptotic response in the pathogenesis of infantile hemangioma (IH).

METHODS AND RESULTS

The staining level of 4-hydroxynonenal (4-HNE), the marker of ferroptotic cells, was significantly increased in the involutive IH samples compared with the proliferative samples (9 proliferative versus 12 involutive lesions, P=0.0152). By contrast, the expression of glutathione peroxidase 4 (GPX4), a key enzyme regulating ferroptotic resistance, was significantly increased in the involutive IH samples. Meanwhile, the GPX4 was richly expressed in macrophages of IH. The data from in vitro study showed that the mRNA (P=0.0002) and protein (P=0.0385) expression levels of GPX4 were significantly upregulated in macrophages cultured with hemangioma-derived stem cells conditional medium (HemSC-CM). Mechanistically, HemSC-CM promoted the expression of GPX4 in macrophages (P=0.0482) by increasing nuclear factor erythroid 2-related factor 2 translocation to the nucleus (P=0.0026). Additionally, inhibition of GPX4 or inducing ferroptosis in macrophages could inhibit progression of lesion in IH nude mice mode.

CONCLUSIONS

Hemangioma-derived stem cells (HemSCs) could promote macrophage ferroptotic resistance through upregulating expression of GPX4, which is required for the progression of IH.

Overexpression of Growth Differentiation Factor 15 Reduces Neuronal Cell Damage Induced by Oxygen-Glucose Deprivation/Reoxygenation via Inhibiting Endoplasmic Reticulum Stress-Mediated Ferroptosis

Growth differentiation factor 15 (GDF15) can be induced under various stress conditions. This study aimed to explore the role of GDF15 in oxygen-glucose deprivation/reoxygenation (OGD/R)-induced HT22 cells. OGD/R was employed to induce the HT22 cell model, and GDF15 expression was upregulated via transfection. Subsequently, the effects on inflammatory factors, oxidative stress markers, apoptosis-related proteins, and ferroptosis markers were detected. Relevant indicators were evaluated using techniques such as ELISA, probes, flow cytometry, and western blotting. Furthermore, changes in these phenotypes under the influence of the endoplasmic reticulum (ER) stress agonist tunicamycin (TM) were evaluated. The result showed that GDF15 was significantly up-regulated in OGD/R-treated HT22 cells. Overexpression of GDF15 significantly reduced the levels of inflammatory factors tumor necrosis factor-α, IL (interleukin)-1β, and IL-6, inhibited the production of reactive oxygen species and MDA, and improved activity of superoxide dismutase and GSH-Px. Flow cytometry and western blotting results showed that GDF15 overexpression significantly reduced cell apoptosis, reduced caspase3 activity, and regulated the expression of Bcl2 and Bax. In addition, overexpression of GDF15 reduces the levels of ferroptosis markers by inhibiting ER stress. ER stress inducer TM can reverse the protective effects of GDF15 overexpression and promote inflammation, oxidative stress, and apoptosis. This study shows that overexpression of GDF15 reduces OGD/R-induced HT22 cell damage, and ER stress-mediated ferroptosis is included in the regulatory mechanisms. This provides a theoretical basis for GDF15 as a new target for the treatment of cerebral ischemia-reperfusion injury.

Sorafenib, a Tyrosine Kinase Inhibitor, Synergistically Enhances the Ferroptosis Effects of Asiatic Acid in Hepatocellular Carcinoma Cells

Hepatocellular carcinoma (HCC) remains one of the most common cancers worldwide. Asiatic acid (AA) is a natural triterpene, which is recognized as effect of antioxidant and antitumor. Sorafenib (Sor), an orally target drug, has been applicate for the HCC therapy. However, the synergistic effect of AA and Sor on human HCC is still unclear. Here, we explore the effect of combined treatment with AA and Sor in the HCC cell line SK-HEP-1 and HepG2. Compared with treating alone, our results demonstrated that AA combined with Sor synergistically inhibited proliferative rates in MTT assay and colony formation assay. We also found that AA combined with Sor in HCC cells strongly caused cell cycle arrest in G0/G1 phase and affected the protein level of cyclin D1 and SKP2. Furthermore, combination treatment strongly enhanced ferroptosis through cellular accumulation of iron ions, lipid peroxidation, and ferroptosis-related proteins (GPX4 and FTH1) in HCC cells. In addition, the combined treatment resulted in higher phosphorylation of JNK1/2 in the promotion of ferroptosis than drug treatment alone. These results indicate that AA combined with Sor synergistically improved ferroptosis in HCC cells through the regulation of JNK1/2 signaling. Taken together, the combinatorial strategy may serve as the potential treatment in HCC.

Kupffer Cell-derived IL6 Promotes Hepatocellular Carcinoma Metastasis Via the JAK1-ACAP4 Pathway

Tumor-associated macrophages (TAMs), which differentiate from tissue-resident macrophages, are recognized for their ability to influence cancer progression and metastasis. However, the specific role of Kupffer cells (KCs), the intrinsic macrophages of the liver, in the progression of hepatocellular carcinoma (HCC) remains unclear. In this study, we describe a novel mechanism by which exosomes derived from HCC cells induce KCs to transition into TAMs, thereby facilitating the metastasis of HCC in an IL6-JAK1-ACAP4 axis-dependent manner. Mechanistically, the exosome-mediated domestication of KCs by hepatoma cells constitutes one of the primary sources of IL6 production in the HCC microenvironment. IL6 then activates JAK1 to phosphorylate its downstream effector ACAP4 at Tyr843, a novel phosphorylation site identified in this context, which in turn promotes ARF6-GTPase activity and hepatoma cell migration. Furthermore, we found that the levels of IL6, as well as the phosphorylation of JAK1 and ACAP4 at Tyr843, were significantly greater in tumor tissues from HCC patients than in adjacent tissues. These findings suggest that the IL6-JAK1-ACAP4 axis may be a promising therapeutic target for HCC. Importantly, we screened bufalin, an active ingredient derived from Venenum Bufonis, and discovered that it inhibits JAK1 and disrupts the IL6-induced phosphorylation of ACAP4. This inhibition not only impairs hepatoma cell migration but also prevents the metastasis of HCC. These findings demonstrate the interplay between hepatoma cells and KCs through the IL6-JAK1-ACAP4 axis, thereby promoting HCC metastasis, and reveal the therapeutic potential of bufalin for the treatment of HCC through JAK1 inhibition.

Artificial intelligence model predicts M2 macrophage levels and HCC prognosis with only globally labeled pathological images

Background and aims

The levels of M2 macrophages are significantly associated with the prognosis of hepatocellular carcinoma (HCC), however, current detection methods in clinical settings remain challenging. Our study aims to develop a weakly supervised artificial intelligence model using globally labeled histological images, to predict M2 macrophage levels and forecast the prognosis of HCC patients by integrating clinical features.

Methods

CIBERSORTx was used to calculate M2 macrophage abundance. We developed a slide-level, weakly-supervised clustering method for Whole Slide Images (WSIs) by integrating Masked Autoencoders (MAE) with ResNet-32t to predict M2 macrophage abundance.

Results

We developed an MAE-ResNet model to predict M2 macrophage levels using WSIs. In the testing dataset, the area under the curve (AUC) (95% CI) was 0.73 (0.59-0.87). We constructed a Cox regression model showing that the predicted probabilities of M2 macrophage abundance were negatively associated with the prognosis of HCC (HR=1.89, p=0.031). Furthermore, we incorporated clinical data, screened variables using Lasso regression, and built the comprehensive prediction model that better predicted prognosis. (HR=2.359, p=0.001).

Conclusion

Our models effectively predicted M2 macrophage levels and HCC prognosis. The findings suggest that our models offer a novel method for determining biomarker levels and forecasting prognosis, eliminating additional clinical tests, thereby delivering substantial clinical benefits.

Targeting caspase-8: a new strategy for combating hepatocellular carcinoma

Hepatocellular carcinoma (HCC) represents the most prevalent form of primary liver cancer and has a high mortality rate. Caspase-8 plays a pivotal role in an array of cellular signaling pathways and is essential for the governance of programmed cell death mechanisms, inflammatory responses, and the dynamics of the tumor microenvironment. Dysregulation of caspase-8 is intricately linked to the complex biological underpinnings of HCC. In this manuscript, we provide a comprehensive review of the regulatory roles of caspase-8 in apoptosis, necroptosis, pyroptosis, and PANoptosis, as well as its impact on inflammatory reactions and the intricate interplay with critical immune cells within the tumor microenvironment, such as tumor-associated macrophages, T cells, natural killer cells, and dendritic cells. Furthermore, we emphasize how caspase-8 plays pivotal roles in the development, progression, and drug resistance observed in HCC, and explore the potential of targeting caspase-8 as a promising strategy for HCC treatment.

Oxymatrine Inhibits PD-L1 by Downregulating IFN-γ to Promote Ferroptosis and Enhance Anti-PD-L1 Efficacy in Liver Cancer

Purpose

Oxymatrine has potent anti-cancer activity, but its exact mechanism in liver cancer remains elusive. The present study was designated to explore oxymatrine's effect and the potential mechanism on Programmed cell death-ligand 1 (PD-L1) expression and ferroptosis in liver cancer.

Methods

Oxymatrine's influence on PD-L1 expression and ferroptosis-related proteins in liver cancer cells was explored in vitro and in vivo utilizing Western blotting, qRT-PCR, immunofluorescence, ELISA, H&E staining, immunohistochemistry, as well as detection of Fe2+, ROS, and MDA.

Results

The in-vivo results showed that xenotransplanted tumor mice with drug interventions (oxymatrine, anti-PD-L1, and combination groups) exhibited inhibited tumor growth compared to control mice. Relative to anti-PD-L1 administration alone, the combined treatment inhibited tumor growth more significantly, along with reduced interferon-γ (IFN-γ) expression in peripheral blood and remarkably increased tumor immune lymphocyte (CD4+ T and CD8+ T) infiltration in cancer tissues. Meanwhile, PD-L1, xCT, and GPX4 protein levels in the combination group were significantly downregulated. According to the in vitro results, IFN-γ promoted PD-L1, xCT, and GPX4 protein levels in liver cancer cell lines. Oxymatrine reversed IFN-γ-induced upregulation of PD-L1 expression; moreover, it downregulated xCT and GPX4 protein levels in liver cancer cells and promoted intracellular Fe2+, ROS, and MDA levels.

Conclusion

Oxymatrine promotes tumor immune response and ferroptosis in liver cancer by downregulating IFN-γ and synergistically enhances the inhibitory effect of anti-PD-L1 on liver cancer.

PCDHGA10 as a potential prognostic biomarker and correlated with immune infiltration in gastric cancer

Background

Gastric cancer (GC) is one of the most common malignant tumors and is associated with poor prognosis. To improve the prognosis of GC patients, an effective immune-related prognostic biomarker is urgent. Here, we aim to explore the correlation between the expression of procalcitonin gamma subfamily A, 10 (PCDHGA10) and clinicopathological characteristics, especially its relation with tumor-infiltrating immune cells (TILs) in GC.

Methods

The differential mRNA expression of PCDHGA10 between GC tissues and normal gastric mucosa and prognostic potential were assessed from The Cancer Genome Atlas (TCGA). Then, based on tissue microarrays (TMAs) with multiplex immunohistochemistry (mIHC) from GC patients, we statistically assess the correlation between PCDHGA10 protein expression and the clinical profiles and prognosis of the patients. Additionally, with IHC and mIHC, we applied the machine-learning algorithms to evaluate the localization and expression levels of TILs and immune checkpoints in the tumor microenvironment. We analyzed the relationship between PCDHGA10 protein expression and TILs and immune checkpoints.

Results

Through the database and TMA analysis, the expression of PCDHGA10 was significantly higher in GC tissues compared with normal tissues. High PCDHGA10 expression independently predicted poor prognosis in GC. Additionally, elevated PCDHGA10 expression was positively associated with the number of CD8+ T cells, CD68+ macrophages, Foxp3+ T cells, and CD4+ T cells in GC tissues and the stromal region. Besides, the expression of PCDHGA10 was positively correlated with immune checkpoints, including CTLA-4, LAG3, and PD-L1.

Conclusions

PCDHGA10 might be a potential prognostic marker and an immunological therapeutic target for GC.

Ferroptosis and the tumor microenvironment

Ferroptosis is a type of regulated cell death characterized by its non-apoptotic, iron-dependent and oxidative nature. Since its discovery in 2012, extensive research has demonstrated its pivotal roles in tumorigenesis, metastasis and cancer therapy. The tumor microenvironment (TME) is a complex ecosystem comprising cancer cells, non-cancer cells, extracellular matrix, metabolites and cytokines. Recent studies have underscored a new paradigm in which non-cancer cells in the TME, such as immune and stromal cells, also play significant roles in regulating tumor progression and therapeutic resistance typically through complicated crosstalk with cancer cells. Notably, this crosstalk in the TME were partially mediated through ferrotopsis-related mechanisms. This review provides a comprehensive and systematic summary of the current findings concerning the roles of ferroptosis in the TME and how ferroptosis-mediated TME reprogramming impacts cancer therapeutic resistance and progression. Additionally, this review outlines various ferroptosis-related therapeutic strategies aimed at targeting the TME.

Investigating the mechanism of ferroptosis induction by sappanone A in hepatocellular carcinoma: NRF2/xCT/GPX4 axis

Hepatocellular carcinoma (HCC) is a prevalent and lethal malignancy with significant global impact, necessitating the development of novel therapeutic strategies and drugs. Ferroptosis, a newly identified form of iron-dependent programmed cell death, has emerged as a promising strategy to combat HCC. Sappanone A, an isoflavone compound derived from the heartwood of Biancaea sappan (L.) Tod., is known for its anti-inflammatory and antioxidant properties. However, its anti-HCC effects and underlying mechanisms remain unclear. This study is the first time to demonstrate the anti-tumor effect of Sappanone A on HCC both in vitro and in vivo, through the assessment of cell viability and apoptosis following Sappanone A treatment. Flow cytometry and confocal microscopy revealed that Sappanone A induced ferroptosis in HCC cells by increasing Fe2+ accumulation, reactive oxygen (ROS) level, and lipid peroxidation, specifically targeting inosine monophosphate dehydrogenase-2 (IMPDH2). Additionally, Western blot analysis suggested that the anti-HCC effects of Sappanone A were mediated through the regulation of the NRF2/xCT/GPX4 axis, highlighting its potential to enhance ferroptosis in HCC cells and underscoring the critical role of IMPDH2 in HCC treatment.

Cuproptosis, ferroptosis and PANoptosis in tumor immune microenvironment remodeling and immunotherapy: culprits or new hope

Normal life requires cell division to produce new cells, but cell death is necessary to maintain balance. Dysregulation of cell death can lead to the survival and proliferation of abnormal cells, promoting tumor development. Unlike apoptosis, necrosis, and autophagy, the newly recognized forms of regulated cell death (RCD) cuproptosis, ferroptosis, and PANoptosis provide novel therapeutic strategies for tumor treatment. Increasing research indicates that the death of tumor and immune cells mediated by these newly discovered forms of cell death can regulate the tumor microenvironment (TME) and influence the effectiveness of tumor immunotherapy. This review primarily elucidates the molecular mechanisms of cuproptosis, ferroptosis, and PANoptosis and their complex effects on tumor cells and the TME. This review also summarizes the exploration of nanoparticle applications in tumor therapy based on in vivo and in vitro evidence derived from the induction or inhibition of these new RCD pathways.

Delivery of SiRNA-PD-L1 by attenuated Salmonella in combination with oxaliplatin in a hepatocellular carcinoma mouse model

Oxaliplatin is currently used for chemotherapy in patients with hepatocellular carcinoma, but its increasing tolerance to tumours over time limits its clinical application. Studies have shown that high PD-L1 expression promotes the polarization of M2 macrophages. The increased infiltration of M2 macrophages, including those in HCC, is positively correlated with poor prognosis in various solid tumours. We found that oxaliplatin promoted the expression of PD-L1 in liver cancer cells, which might be attributed partly to the tolerance of tumours to oxaliplatin. Therefore, in this study, we explored the antitumour effect of attenuated Salmonella carrying siRNA-PD-L1 combined with oxaliplatin via Western blotting, immunohistochemistry, immunofluorescence, and flow cytometry. The results revealed that attenuated Salmonella carrying siRNA-PD-L1 combined with oxaliplatin more significantly inhibited tumour growth in tumour-bearing mice, suppressed the expression of PD-L1 in tumour tissue, increased the apoptosis of tumour cells and the expression of the tumour-related protein cleaved-caspase3, and increased the infiltration of M1 macrophages and T lymphocytes in tumour tissues. Moreover, the combination therapy increased the activation of T cells and the number of T lymphocytes and NK cells in the spleens of the mice and improved the overall antitumour immune response in the mice. Our results confirmed that attenuated Salmonella harbouring siRNA-PD-L1 combined with oxaliplatin had a significant antitumour effect and did not increase the incidence of toxic side effects, providing a theoretical reference for addressing oxaliplatin tolerance in the treatment of hepatocellular carcinoma.

Ferroptosis: insight into the treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignances in the world, with high morbidity and mortality. Due to the hidden onset of symptoms, there are huge obstacles in early diagnosis, recurrence, metastasis and drug resistance. Although great strides have been made in the treatment of HCC, effective treatment options are still limited and achieving longer survival for patients remains urgent. Ferroptosis is a novel type of programmed cell death that is mainly caused by iron-dependent oxidative damage. With further investigations, ferroptosis has been proved to be associated with the occurrence and development of various tumors. This article reviews the regulatory mechanism and signal transduction pathways of ferroptosis, investigates the complex relationship between autophagy, sorafenib resistance and immunotherapy with ferroptosis involved in HCC, providing new ideas and directions for the treatment of HCC.

Targeted Positron Emission Tomography-Tracked Biomimetic Codelivery Synergistically Amplifies Ferroptosis and Pyroptosis for Inducing Lung Cancer Regression and Anti-PD-L1 Immunotherapy Efficacy

The chemoresistance and systemic toxicity of cisplatin (CDDP) severely limit its application in the treatment of non-small cell lung cancer (NSCLC). Here, I-124 labeled cancer cell membrane biomimetic nanovesicles loading Polyphyllin VI (PPVI) and CDDP (termed 124I-P/C@CMLvs) were constructed to enhance the sensitivity and efficacy of CDDP. The radiochemical purity (RCP) of 124I-P/C@CMLvs reached more than 99% and maintained reliable stability in vitro. Micro-positron emission tomography (micro-PET) imaging of I-124 quantitatively revealed the distribution and specific homologous tumor targeting ability of 124I-P/C@CMLvs in vivo with superior diagnosis performance, beneficial for dynamically monitoring the efficacy against NSCLC. Loaded PPVI significantly strengthened the sensitivity of NSCLC to CDDP therapy and exerted synergistic anti-tumor effect in vitro and in vivo, which was achieved by PPVI promoting p53 deubiquitination and stimulating reactive oxygen species (ROS) production to trigger the crosstalk between the amplification of GPX4 signaling-mediated ferroptosis and NLRP3/GSDMD/Caspase-1 axis-mediated pyroptosis. 124I-P/C@CMLvs also significantly stimulated the infiltration of immune cells including dendritic cells, CD8+ T cells, and CD4+ T cells in tumor tissues (P < 0.05). The combination of 124I-P/C@CMLvs and anti-PD-L1 therapy further synergistically promoted NSCLC regression. Altogether, 124I-P/C@CMLvs provide a transformational solution to the challenge of improving CDDP sensitivity and realizing the integration of diagnosis, treatment, and monitoring of NSCLC.

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.

Progress in research of ferroptosis in gastrointestinal tumors

Ferroptosis is a non-apoptotic and oxidation-damaged regulated cell death caused by iron accumulation, lipid peroxidation, and subsequent plasma membrane rupture. Ferroptosis is the main cause of tissue damage caused by iron overload and lipid peroxidation. With the deepening of the research in recent years, the understanding of the occurrence and treatment of tumors has made a major breakthrough, which brings new strategies for anti-cancer treatment. This paper reviews the relationship between ferroptosis and gastrointestinal tumors, the research of ferroptosis in cancer prevention and treatment, and the role of ferroptosis in the prevention and treatment of gastrointestinal tumors.

Drug resistance and tumor immune microenvironment: An overview of current understandings (Review)

The use of antitumor drugs represents a reliable strategy for cancer therapy. Unfortunately, drug resistance has become increasingly common and contributes to tumor metastasis and local recurrence. The tumor immune microenvironment (TME) consists of immune cells, cytokines and immunomodulators, and collectively they influence the response to treatment. Epigenetic changes including DNA methylation and histone modification, as well as increased drug exportation have been reported to contribute to the development of drug resistance in cancers. In the past few years, the majority of studies on tumors have only focused on the development and progression of a tumor from a mechanistic standpoint; few studies have examined whether the changes in the TME can also affect tumor growth and drug resistance. Recently, emerging evidence have raised more concerns regarding the role of TME in the development of drug resistance. In the present review, it was discussed how the suppressive TME adapts to drug resistance characterized by the cooperation of immune cells, cytokines, immunomodulators, stromal cells and extracellular matrix. Furthermore, it was reviewed how these immunological or metabolic changes alter immuno‑surveillance and thus facilitate tumor drug resistance. In addition, potential targets present in the TME for developing novel therapeutic strategies to improve individualized therapy for cancer treatment were revealed.

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.

Identification of TACSTD2 as novel therapeutic targets for cisplatin-induced acute kidney injury by multi-omics data integration

Cisplatin-induced acute kidney injury (CP-AKI) is a common complication in cancer patients. Although ferroptosis is believed to contribute to the progression of CP-AKI, its mechanisms remain incompletely understood. In this study, after initially processed individual omics datasets, we integrated multi-omics data to construct a ferroptosis network in the kidney, resulting in the identification of the key driver TACSTD2. In vitro and in vivo results showed that TACSTD2 was notably upregulated in cisplatin-treated kidneys and BUMPT cells. Overexpression of TACSTD2 accelerated ferroptosis, while its gene disruption decelerated ferroptosis, likely mediated by its potential downstream targets HMGB1, IRF6, and LCN2. Drug prediction and molecular docking were further used to propose that drugs targeting TACSTD2 may have therapeutic potential in CP-AKI, such as parthenolide, progesterone, premarin, estradiol and rosiglitazone. Our findings suggest a significant association between ferroptosis and the development of CP-AKI, with TACSTD2 playing a crucial role in modulating ferroptosis, which provides novel perspectives on the pathogenesis and treatment of CP-AKI.

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.

Ferroptosis in hepatocellular carcinoma: from bench to bedside

The most widespread type of liver cancer, HCC, is associated with disabled cellular death pathways. Despite therapeutic advancements, resistance to current systemic treatments (including sorafenib) compromises the prognosis of patients with HCC, driving the search for agents that might target novel cell death pathways. Ferroptosis, a form of iron-mediated nonapoptotic cell death, has gained considerable attention as a potential target for cancer therapy, especially in HCC. The role of ferroptosis in HCC is complex and diverse. On one hand, ferroptosis can contribute to the progression of HCC through its involvement in both acute and chronic liver conditions. In contrast, having ferroptosis affect HCC cells might be desirable. This review examines the role of ferroptosis in HCC from cellular, animal, and human perspectives while examining its mechanisms, regulation, biomarkers, and clinical implications.

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.

The role of tumor-associated macrophages in hepatocellular carcinoma-from bench to bedside: A review

Hepatocellular carcinoma is one of the most common cancers worldwide. Despite progress in treatment, recurrence after radical treatment is common, and the prognosis remains poor for patients with advanced disease. Therefore, there is a need to identify prognostic and predictive factors for the response to therapy or more intensive surveillance or treatment. Because the tumor microenvironment plays a crucial role in the development of cancer and metastasis, it is a crucial need to understand processes that are involved in carcinogenesis. Within the microenvironment, several immune cells with different roles are present. One of the most important of these is tumor-associated macrophages. These cells may exert either antitumor or protumor roles. Several studies have suggested that tumor-associated macrophages can be used as prognostic markers. Furthermore, they may be involved in resistance to immunotherapy or systemic treatment. As they play an important role in cancer development, tumor-associated macrophages are also a good target for therapy. In this review, we briefly summarize recent progress on knowledge regarding the basic molecular characteristics, impact on prognosis and potential clinical implications of tumor-associated macrophages in hepatocellular carcinoma.

Targeting novel regulated cell death: Ferroptosis, pyroptosis and necroptosis in anti-PD-1/PD-L1 cancer immunotherapy

Chemotherapy, radiotherapy, and immunotherapy represent key tumour treatment strategies. Notably, immune checkpoint inhibitors (ICIs), particularly anti-programmed cell death 1 (PD1) and anti-programmed cell death ligand 1 (PD-L1), have shown clinical efficacy in clinical tumour immunotherapy. However, the limited effectiveness of ICIs is evident due to many cancers exhibiting poor responses to this treatment. An emerging avenue involves triggering non-apoptotic regulated cell death (RCD), a significant mechanism driving cancer cell death in diverse cancer treatments. Recent research demonstrates that combining RCD inducers with ICIs significantly enhances their antitumor efficacy across various cancer types. The use of anti-PD-1/PD-L1 immunotherapy activates CD8+ T cells, prompting the initiation of novel RCD forms, such as ferroptosis, pyroptosis, and necroptosis. However, the functions and mechanisms of non-apoptotic RCD in anti-PD1/PD-L1 therapy remain insufficiently explored. This review summarises the emerging roles of ferroptosis, pyroptosis, and necroptosis in anti-PD1/PD-L1 immunotherapy. It emphasises the synergy between nanomaterials and PD-1/PD-L1 inhibitors to induce non-apoptotic RCD in different cancer types. Furthermore, targeting cell death signalling pathways in combination with anti-PD1/PD-L1 therapies holds promise as a prospective immunotherapy strategy for tumour treatment.

Discovery of New Phenyltetrazolium Derivatives as Ferroptosis Inhibitors for Treating Ischemic Stroke: An Example Development from Free Radical Scavengers

Ferroptosis is a promising therapeutic target for injury-related diseases, yet diversity in ferroptosis inhibitors remains limited. In this study, initial structure optimization led us to focus on the bond dissociation enthalpy (BDE) of the N-H bond and the residency time of radical scavengers in a phospholipid bilayer, which may play an important role in ferroptosis inhibition potency. This led to the discovery of compound D1, exhibiting potent ferroptosis inhibition, high radical scavenging, and moderate membrane permeability. D1 demonstrated significant neuroprotection in an oxygen glucose deprivation/reoxygenation (OGD/R) model and reduced infarct volume in an in vivo stroke model upon intravenous treatment. Further screening based on this strategy identified NecroX-7 and Eriodictyol-7-O-glucoside as novel ferroptosis inhibitors with highly polar structural characteristics. This approach bridges the gap between free radical scavengers and ferroptosis inhibitors, providing a foundation for research and insights into novel ferroptosis inhibitor development.

TRIM59 deficiency promotes M1 macrophage activation and inhibits colorectal cancer through the STAT1 signaling pathway

Tumor-associated macrophages play a crucial role in the tumor microenvironment. Tripartite motif 59 (TRIM59), a member of the tripartite motif (TRIM) family, is known to be associated with immunological diseases and macrophage activation. The functional and molecular mechanisms by which TRIM59 affects the occurrence and development of colorectal cancer (CRC) through macrophages are still not well understood. To address this, we generated macrophage-specific TRIM59 conditional knockout mice and utilized these mice to establish colitis-associated cancer and MC38 transplanted CRC models for further investigation. We found that the deficiency of TRIM59 in macrophages inhibited colorectal tumorigenesis in mice. This tumor-suppressive effect was achieved by promoting the activation of M1 macrophages via STAT1 signaling pathway. Further mechanistic studies revealed that TRIM59 could regulate macrophage polarization by ubiquitinating and degrading STAT1. These findings provide evidence that TRIM59 deficiency promotes M1 macrophage activation and inhibits CRC through the STAT1 signaling pathway, suggesting that the TRIM59/STAT1 signaling pathway may be a promising target for CRC.

Developing an advanced diagnostic model for hepatocellular carcinoma through multi-omics integration leveraging diverse cell-death patterns

Introduction

Hepatocellular carcinoma (HCC), representing more than 80% of primary liver cancer cases, lacks satisfactory etiology and diagnostic methods. This study aimed to elucidate the role of programmed cell death-associated genes (CDRGs) in HCC by constructing a diagnostic model using single-cell RNA sequencing (scRNA-seq) and RNA sequencing (RNA-seq) data.

Methods

Six categories of CDRGs, including apoptosis, necroptosis, autophagy, pyroptosis, ferroptosis, and cuproptosis, were collected. RNA-seq data from blood-derived exosomes were sourced from the exoRBase database, RNA-seq data from cancer tissues from the TCGA database, and scRNA-seq data from the GEO database. Subsequently, we intersected the differentially expressed genes (DEGs) of the HCC cohort from exoRBase and TCGA databases with CDRGs, as well as DEGs obtained from single-cell datasets. Candidate biomarker genes were then screened using clinical indicators and a machine learning approach, resulting in the construction of a seven-gene diagnostic model for HCC. Additionally, scRNA-seq and spatial transcriptome sequencing (stRNA-seq) data of HCC from the Mendeley data portal were used to investigate the underlying mechanisms of these seven key genes and their association with immune checkpoint blockade (ICB) therapy. Finally, we validated the expression of key molecules in tissues and blood-derived exosomes through quantitative Polymerase Chain Reaction (qPCR) and immunohistochemistry experiments.

Results

Collectively, we obtained a total of 50 samples and 104,288 single cells. Following the meticulous screening, we established a seven-gene diagnostic model for HCC, demonstrating high diagnostic efficacy in both the exoRBase HCC cohort (training set: AUC = 1; testing set: AUC = 0.847) and TCGA HCC cohort (training set: AUC = 1; testing set: AUC = 0.976). Subsequent analysis revealed that HCC cluster 3 exhibited a higher stemness index and could serve as the starting point for the differentiation trajectory of HCC cells, also displaying more abundant interactions with other cell types in the microenvironment. Notably, key genes TRIB3 and NQO1 displayed elevated expression levels in HCC cells. Experimental validation further confirmed their elevated expression in both tumor tissues and blood-derived exosomes of cancer patients. Additionally, stRNA analysis not only substantiated these findings but also suggested that patients with high TRIB3 and NQO1 expression might respond more favorably to ICB therapy.

Conclusions

The seven-gene diagnostic model demonstrated remarkable accuracy in HCC screening, with TRIB3 emerging as a promising diagnostic tool and therapeutic target for HCC.

SLC7A11: the Achilles heel of tumor?

The non-natriuretic-dependent glutamate/cystine inverse transporter-system Xc- is composed of two protein subunits, SLC7A11 and SLC3A2, with SLC7A11 serving as the primary functional component responsible for cystine uptake and glutathione biosynthesis. SLC7A11 is implicated in tumor development through its regulation of redox homeostasis, amino acid metabolism, modulation of immune function, and induction of programmed cell death, among other processes relevant to tumorigenesis. In this paper, we summarize the structure and biological functions of SLC7A11, and discuss its potential role in tumor therapy, which provides a new direction for precision and personalized treatment of tumors.

The multifaceted perspectives on the regulation of lncRNAs in hepatocellular carcinoma ferroptosis: from bench-to-bedside

Despite being characterized by high malignancy, high morbidity, and low survival rates, the underlying mechanism of hepatocellular carcinoma (HCC) has not been fully elucidated. Ferroptosis, a non-apoptotic form of regulated cell death, possesses distinct morphological, biochemical, and genetic characteristics compared to other types of cell death. Dysregulated actions within the molecular network that regulates ferroptosis have been identified as significant contributors to the progression of HCC. Long non-coding RNAs (lncRNAs) have emerged as influential contributors to diverse cellular processes, regulating gene function and expression through multiple mechanistic pathways. An increasing body of evidence indicates that deregulated lncRNAs are implicated in regulating malignant events such as cell proliferation, growth, invasion, and metabolism by influencing ferroptosis in HCC. Therefore, elucidating the inherent role of ferroptosis and the modulatory functions of lncRNAs on ferroptosis in HCC might promote the development of novel therapeutic interventions for this disease. This review provides a succinct overview of the roles of ferroptosis and ferroptosis-related lncRNAs in HCC progression and treatment, aiming to drive the development of promising therapeutic targets and biomarkers for HCC patients.

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.

TRIM47-CDO1 axis dictates hepatocellular carcinoma progression by modulating ferroptotic cell death through the ubiquitin‒proteasome system

Hepatocellular carcinoma (HCC) is the predominant form of liver cancer, characterized by high morbidity and mortality rates, as well as unfavorable treatment outcomes. Tripartite motif-containing protein 47 (TRIM47) has been implicated in various diseases including tumor progression with the activity of E3 ubiquitin ligase. However, the precise regulatory mechanisms underlying the involvement of TRIM47 in HCC remain largely unexplored. Here, we provide evidence that TRIM47 exhibits heightened expression in tumor tissues, and its expression is in intimate association with clinical staging and patient prognosis. TRIM47 promotes HCC proliferation, migration, and invasion as an oncogene by in vitro gain- and loss-of-function experiments. TRIM47 knockdown results in HCC ferroptosis induction, primarily through CDO1 involvement to regulate GSH synthesis. Subsequent experiments confirm the interaction between TRIM47 and CDO1 dependent on B30.2 domain, wherein TRIM47 facilitates K48-linked ubiquitination, leading to a decrease in CDO1 protein abundance in HCC. Furthermore, CDO1 is able to counteract the promotional effect of TRIM47 on HCC biological functions. Overall, our research provides novel insight into the mechanism of TRIM47 in CDO1-mediated ferroptosis in HCC cells, highlighting its value as a potential target candidate for HCC therapeutic approaches.

Ferroptosis in antitumor therapy: Unraveling regulatory mechanisms and immunogenic potential

Ferroptosis, a recently discovered form of non-apoptotic cell death, has the potential to revolutionize anti-tumor therapy. This review highlights the regulatory mechanisms and immunogenic properties of ferroptosis, and how it can enhance the effectiveness of radio and immunotherapies in overcoming tumor resistance. However, tumor metabolism and the impact of ferroptosis on the tumor microenvironment present challenges in completely realizing its therapeutic potential. A deeper understanding of the effects of ferroptosis on tumor cells and their associated immune cells is essential for developing more effective tumor treatment strategies. This review offers a comprehensive overview of the relationship between ferroptosis and tumor immunity, and sheds new light on its application in tumor immunotherapy.

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.

Nanomaterials modulate tumor-associated macrophages for the treatment of digestive system tumors

The treatment of digestive system tumors presents challenges, particularly in immunotherapy, owing to the advanced immune tolerance of the digestive system. Nanomaterials have emerged as a promising approach for addressing these challenges. They provide targeted drug delivery, enhanced permeability, high bioavailability, and low toxicity. Additionally, nanomaterials target immunosuppressive cells and reshape the tumor immune microenvironment (TIME). Among the various cells in the TIME, tumor-associated macrophages (TAMs) are the most abundant and play a crucial role in tumor progression. Therefore, investigating the modulation of TAMs by nanomaterials for the treatment of digestive system tumors is of great significance. Here, we present a comprehensive review of the utilization of nanomaterials to modulate TAMs for the treatment of gastric cancer, colorectal cancer, hepatocellular carcinoma, and pancreatic cancer. We also investigated the underlying mechanisms by which nanomaterials modulate TAMs to treat tumors in the digestive system. Furthermore, this review summarizes the role of macrophage-derived nanomaterials in the treatment of digestive system tumors. Overall, this research offers valuable insights into the development of nanomaterials tailored for the treatment of digestive system tumors.

Regulation of ferroptosis by nanotechnology for enhanced cancer immunotherapy

INTRODUCTION

This review explores the innovative intersection of ferroptosis, a form of iron-dependent cell death, with cancer immunotherapy. Traditional cancer treatments face limitations in efficacy and specificity. Ferroptosis as a new paradigm in cancer biology, targets metabolic peculiarities of cancer cells and may potentially overcome such limitations, enhancing immunotherapy.

AREA COVERED

This review centers on the regulation of ferroptosis by nanotechnology to augment immunotherapy. It explores how nanoparticle-modulated ferroptotic cancer cells impact the TME and immune responses. The dual role of nanoparticles in modulating immune response through ferroptosis are also discussed. Additionally, it investigates how nanoparticles can be integrated with various immunotherapeutic strategies, to optimize ferroptosis induction and cancer treatment efficacy. The literature search was conducted using PubMed and Google Scholar, covering articles published up to March 2024.

EXPERT OPINION

The manuscript underscores the promising yet intricate landscape of ferroptosis in immunotherapy. It emphasizes the need for a nuanced understanding of ferroptosis' impact on immune cells and the TME to develop more effective cancer treatments, highlighting the potential of nanoparticles in enhancing the efficacy of ferroptosis and immunotherapy. It calls for deeper exploration into the molecular mechanisms and clinical potential of ferroptosis to fully harness its therapeutic benefits in immunotherapy.

Apoptotic Bodies Derived from Fibroblast-Like Cells in Subcutaneous Connective Tissue Inhibit Ferroptosis in Ischaemic Flaps via the miR-339-5p/KEAP1/Nrf2 Axis

Preventing and treating avascular necrosis at the distal end of the flaps are critical to surgery success, but current treatments are not ideal. A recent study shows that apoptotic bodies (ABs) generated near the site of apoptosis can be taken up and promote cell proliferation. The study reveals that ABs derived from fibroblast-like cells in the subcutaneous connective tissue (FSCT cells) of skin flaps promoted ischaemic flap survival. It is also found that ABs inhibited cell death and oxidative stress and promoted M1-to-M2 polarization in macrophages. Transcriptome sequencing and protein level testing demonstrated that ABs promoted ischaemic flap survival in endothelial cells and macrophages by inhibiting ferroptosis via the KEAP1-Nrf2 axis. Furthermore, microRNA (miR) sequencing data and in vitro and in vivo experiments demonstrated that ABs inhibited KEAP1 by delivering miR-339-5p to exert therapeutic effects. In conclusion, FSCT cell-derived ABs inhibited ferroptosis, promoted the macrophage M1-to-M2 transition via the miR-339-5p/KEAP1/Nrf2 axis and promoted ischaemic flap survival. These results provide a potential therapeutic strategy to promote ischaemic flap survival by administering ABs.

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.

A novel insight into cancer therapy: Lipid metabolism in tumor-associated macrophages

The tumor immune microenvironment (TIME) can limit the effectiveness and often leads to significant side effects of conventional cancer therapies. Consequently, there is a growing interest in identifying novel targets to enhance the efficacy of targeted cancer therapy. More research indicates that tumor-associated macrophages (TAMs), originating from peripheral blood monocytes generated from bone marrow myeloid progenitor cells, play a crucial role in the tumor microenvironment (TME) and are closely associated with resistance to traditional cancer therapies. Lipid metabolism alterations have been widely recognized as having a significant impact on tumors and their immune microenvironment. Lipids, lipid derivatives, and key substances in their metabolic pathways can influence the carcinogenesis and progression of cancer cells by modulating the phenotype, function, and activity of TAMs. Therefore, this review focuses on the reprogramming of lipid metabolism in cancer cells and their immune microenvironment, in which the TAMs are especially concentrated. Such changes impact TAMs activation and polarization, thereby affecting the tumor cell response to treatment. Furthermore, the article explores the potential of targeting the lipid metabolism of TAMs as a supplementary approach to conventional cancer therapies. It reviews and evaluates current strategies for enhancing efficacy through TAMs' lipid metabolism and proposes new lipid metabolism targets as potential synergistic options for chemo-radiotherapy and immunotherapy. These efforts aim to stimulate further research in this area.

Aberrant Expression of SLC7A11 Impairs the Antimicrobial Activities of Macrophages in Staphylococcus Aureus Osteomyelitis in Mice

Staphylococcus aureus (S. aureus) persistence in macrophages, potentially a reservoir for recurrence of chronic osteomyelitis, contributes to resistance and failure in treatment. As the mechanisms underlying survival of S. aureus in macrophages remain largely unknown, there has been no treatment approved. Here, in a mouse model of S. aureus osteomyelitis, we identified significantly up-regulated expression of SLC7A11 in both transcriptomes and translatomes of CD11b+F4/80+ macrophages, and validated a predominant distribution of SLC7A11 in F4/80+ cells around the S. aureus abscess. Importantly, pharmacological inhibition or genetic knockout of SLC7A11 promoted the bactericidal function of macrophages, reduced bacterial burden in the bone and improved bone structure in mice with S. aureus osteomyelitis. Mechanistically, aberrantly expressed SLC7A11 down-regulated the level of intracellular ROS and reduced lipid peroxidation, contributing to the impaired bactericidal function of macrophages. Interestingly, blocking SLC7A11 further activated expression of PD-L1 via the ROS-NF-κB axis, and a combination therapy of targeting both SLC7A11 and PD-L1 significantly enhanced the efficacy of clearing S. aureus in vitro and in vivo. Our findings suggest that targeting both SLC7A11 and PD-L1 is a promising therapeutic approach to reprogram the bactericidal function of macrophages and promote bacterial clearance in S. aureus osteomyelitis.

Disulfidptosis-related signature elucidates the prognostic, immunologic, and therapeutic characteristics in ovarian cancer

Introduction

Ovarian cancer (OC) is the deadliest malignancy in gynecology, but the mechanism of its initiation and progression is poorly elucidated. Disulfidptosis is a novel discovered type of regulatory cell death. This study aimed to develop a novel disulfidptosis-related prognostic signature (DRPS) for OC and explore the effects and potential treatment by disulfidptosis-related risk stratification.

Methods

The disulfidptosis-related genes were first analyzed in bulk RNA-Seq and a prognostic nomogram was developed and validated by LASSO algorithm and multivariate cox regression. Then we systematically assessed the clinicopathological and mutational characteristics, pathway enrichment analysis, immune cell infiltration, single-cell-level expression, and drug sensitivity according to DRPS.

Results

The DRPS was established with 6 genes (MYL6, PDLIM1, ACTN4, FLNB, SLC7A11, and CD2AP) and the corresponding prognostic nomogram was constructed based on the DRPS, FIGO stage, grade, and residual disease. Stratified by the risk score derived from DRPS, patients in high-risk group tended to have worse prognosis, lower level of disulfidptosis, activated oncogenic pathways, inhibitory tumor immune microenvironment, and higher sensitivity to specific drugs including epirubicin, stauroporine, navitoclax, and tamoxifen. Single-cell transcriptomic analysis revealed the expression level of genes in the DRPS significantly varied in different cell types between tumor and normal tissues. The protein-level expression of genes in the DRPS was validated by the immunohistochemical staining analysis.

Conclusion

In this study, the DRPS and corresponding prognostic nomogram for OC were developed, which was important for OC prognostic assessment, tumor microenvironment modification, drug sensitivity prediction, and exploration of potential mechanisms in tumor development.

CD4 T cell-secreted IFN-γ in Sjögren's syndrome induces salivary gland epithelial cell ferroptosis

BACKGROUND

Sjögren's syndrome (SS) is a chronic autoimmune disease that predominantly affects exocrine glands. Previous studies have demonstrated that upregulated interferon-gamma (IFN-γ) in SS triggers ferroptosis in salivary gland epithelial cells (SGECs), resulting in impaired salivary gland secretion. However, the immune cells responsible for secreting IFN-γ remain unclear. Therefore, this study conducted bioinformatics analysis and molecular validation to identify the origin of IFN-γ in SS salivary gland.

METHODS

The 'limma' package in R software was utilized to identify differentially expressed genes (DEGs) in the human SS dataset. Subsequently, the identified DEGs were compared with the ferroptosis database and screened through Cytoscape to determine candidate genes. The cellular localization and expression patterns of candidate genes were further confirmed in the salivary gland single-cell RNA sequence (scRNA-seq) data set from healthy control and SS mice. Furthermore, in vitro and in vivo studies were performed to analyze the effect of CD4 T-secreted IFN-γ on SGECs' ferroptosis and functions.

RESULTS

Upregulated TLR4, IFNG, and IL33 were screened as candidates ferroptosis ferroptosis-inducing genes in SS salivary glands. The association of IFNG and IL33 with CD4 T cells was established through immune infiltration analysis. The expression of IFN-γ on CD4 T cells was robustly higher compared with that of IL33 as evidenced by scRNA-seq and immunofluorescence co-localization. Subsequent experiments conducted on candidate genes consistently demonstrated the potent ability of IFN-γ to induce SGECs' ferroptosis and inhibit AQP5 expression.

CONCLUSIONS

Our findings indicate that CD4 T cell-secreted IFN-γ in SS induces SGECs' ferroptosis and inhibits AQP5 expression.

Dihydroartemisinin induces ferroptosis of hepatocellular carcinoma via inhibiting ATF4-xCT pathway

Management of hepatocellular carcinoma (HCC) remains challenging due to population growth, frequent recurrence and drug resistance. Targeting of genes involved with the ferroptosis is a promising alternative treatment strategy for HCC. The present study aimed to investigate the effect of dihydroartemisinin (DHA) against HCC and explore the underlying mechanisms. The effects of DHA on induction of ferroptosis were investigated with the measurement of malondialdehyde concentrations, oxidised C11 BODIPY 581/591 staining, as well as subcutaneous xenograft experiments. Activated transcription factor 4 (ATF4) and solute carrier family 7 member 11 (SLC7A11 or xCT) were overexpressed with lentiviruses to verify the target of DHA. Here, we confirmed the anticancer effect of DHA in inducing ferroptosis is related to ATF4. High expression of ATF4 is related to worse clinicopathological prognosis of HCC. Mechanistically, DHA inhibited the expression of ATF4, thereby promoting lipid peroxidation and ferroptosis of HCC cells. Overexpression of ATF4 rescued DHA-induced ferroptosis. Moreover, ATF4 could directly bound to the SLC7A11 promoter and increase its transcription. In addition, DHA enhances the chemosensitivity of sorafenib on HCC in vivo and in vitro. These findings confirm that DHA induces ferroptosis of HCC via inhibiting ATF4-xCT pathway, thereby providing new drug options for the treatment of HCC.

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.

Ferroptosis: a new hunter of hepatocellular carcinoma

Ferroptosis is an iron ion-dependent, regulatory cell death modality driven by intracellular lipid peroxidation that plays a key role in the development of HCC. Studies have shown that various clinical agents (e.g., sorafenib) have ferroptosis inducer-like effects and can exert therapeutic effects by modulating different key factors in the ferroptosis pathway. This implies that targeting tumor cell ferroptosis may be a very promising strategy for tumor therapy. In this paper, we summarize the prerequisites and defense systems for the occurrence of ferroptosis and the regulatory targets of drug-mediated ferroptosis action in HCC, the differences and connections between ferroptosis and other programmed cell deaths. We aim to summarize the theoretical basis, classical inducers of ferroptosis and research progress of ferroptosis in HCC cells, clued to the treatment of HCC by regulating ferroptosis network. Further investigation of the specific mechanisms of ferroptosis and the development of hepatocellular carcinoma and interventions at different stages of hepatocellular carcinoma will help us to deepen our understanding of hepatocellular carcinoma, with a view to providing new and more precise preventive as well as therapeutic measures for patients.

Ferroptosis in cancer: From molecular mechanisms to therapeutic strategies

Ferroptosis is a non-apoptotic form of regulated cell death characterized by the lethal accumulation of iron-dependent membrane-localized lipid peroxides. It acts as an innate tumor suppressor mechanism and participates in the biological processes of tumors. Intriguingly, mesenchymal and dedifferentiated cancer cells, which are usually resistant to apoptosis and traditional therapies, are exquisitely vulnerable to ferroptosis, further underscoring its potential as a treatment approach for cancers, especially for refractory cancers. However, the impact of ferroptosis on cancer extends beyond its direct cytotoxic effect on tumor cells. Ferroptosis induction not only inhibits cancer but also promotes cancer development due to its potential negative impact on anticancer immunity. Thus, a comprehensive understanding of the role of ferroptosis in cancer is crucial for the successful translation of ferroptosis therapy from the laboratory to clinical applications. In this review, we provide an overview of the recent advancements in understanding ferroptosis in cancer, covering molecular mechanisms, biological functions, regulatory pathways, and interactions with the tumor microenvironment. We also summarize the potential applications of ferroptosis induction in immunotherapy, radiotherapy, and systemic therapy, as well as ferroptosis inhibition for cancer treatment in various conditions. We finally discuss ferroptosis markers, the current challenges and future directions of ferroptosis in the treatment of cancer.

Blockade of PD-1 and CTLA-4: A potent immunotherapeutic approach for hepatocellular carcinoma

Immune checkpoints (ICPs) can promote tumor growth and prevent immunity-induced cancer cell apoptosis. Fortunately, targeting ICPs, such as programmed cell death 1 (PD-1) or cytotoxic T lymphocyte associated protein 4 (CTLA-4), has achieved great success in the past few years and has gradually become an effective treatment for cancers, including hepatocellular carcinoma (HCC). However, many patients do not respond to ICP therapy due to acquired resistance and recurrence. Therefore, clarifying the specific mechanisms of ICP in the development of HCC is very important for enhancing the efficacy of anti-PD-1 and anti-CTLA-4 therapy. In particular, antigen presentation and interferon-γ (IFN-γ) signaling were reported to be involved in the development of resistance. In this review, we have explained the role and regulatory mechanisms of ICP therapy in HCC pathology. Moreover, we have also elaborated on combinations of ICP inhibitors and other treatments to enhance the antitumor effect. Collectively, recent advances in the pharmacological targeting of ICPs provide insights for the development of a novel alternative treatment for HCC.