IL-1β-Induced Elevation of Solute Carrier Family 7 Member 11 Promotes Hepatocellular Carcinoma Metastasis Through Up-regulating Programmed Death Ligand 1 and Colony-Stimulating Factor 1

Targeting BMP2 for therapeutic strategies against hepatocellular carcinoma

OBJECTIVES

This study aimed to investigate the role of BMP2 in hepatocellular carcinoma (HCC) growth and metastasis using a dual approach combining single-cell RNA sequencing (scRNA-seq) and bulk RNA-seq.

METHODS

scRNA-seq data from the GEO database and bulk RNA-seq data from the TCGA database were analyzed. Differentially expressed marker genes of endothelial cells were identified and analyzed using enrichment analysis, PPI analysis, correlation analysis, and GSEA. In vitro, experiments were conducted using the Huh-7 HCC cell line, and in vivo, models of HCC growth and metastasis were established by knocking down BMP2.

RESULTS

The scRNA-seq analysis identified BMP2 as a key marker gene in endothelial cells of HCC samples. Elevated BMP2 expression correlated with poor prognosis in HCC. In vitro experiments showed that silencing BMP2 inhibited the proliferation, migration, and invasion of liver cancer cells. In vivo studies confirmed increased BMP2 expression in HCC tissues, promoting angiogenesis and HCC growth.

CONCLUSION

This study highlights the role of BMP2 in tumor angiogenesis and HCC progression. Targeting BMP2 could be a promising therapeutic strategy against HCC.

TGF-β1-Induced SOX18 Elevation Promotes Hepatocellular Carcinoma Progression and Metastasis Through Transcriptionally Upregulating PD-L1 and CXCL12

BACKGROUND & AIMS

Hepatocellular carcinoma (HCC) is characterized by an immune-suppressive microenvironment, which contributes to tumor progression, metastasis, and immunotherapy resistance. Identification of HCC-intrinsic factors regulating the immunosuppressive microenvironment is urgently needed. Here, we aimed to elucidate the role of SYR-Related High-Mobility Group Box 18 (SOX18) in inducing immunosuppression and to validate novel combination strategies for SOX18-mediated HCC progression and metastasis.

METHODS

The role of SOX18 in HCC was investigated in orthotopic allografts and diethylinitrosamine/carbon tetrachloride-induced spontaneous models by using murine cell lines, adeno-associated virus 8, and hepatocyte-specific knockin and knockout mice. The immune cellular composition in the HCC microenvironment was evaluated by flow cytometry and immunofluorescence.

RESULTS

SOX18 overexpression promoted the infiltration of tumor-associated macrophages (TAMs) and regulatory T cells (Tregs) while diminishing cytotoxic T cells to facilitate HCC progression and metastasis in cell-derived allografts and chemically induced HCC models. Mechanistically, transforming growth factor-beta 1 (TGF-β1) upregulated SOX18 expression by activating the Smad2/3 complex. SOX18 transactivated chemokine (C-X-C motif) ligand 12 (CXCL12) and programmed death ligand 1 (PD-L1) to induce the immunosuppressive microenvironment. CXCL12 knockdown significantly attenuated SOX18-induced TAMs and Tregs accumulation and HCC dissemination. Antagonism of chemokine receptor 4 (CXCR4), the cognate receptor of CXCL12, or selective knockout of CXCR4 in TAMs or Tregs likewise abolished SOX18-mediated effects. TGFβR1 inhibitor Vactosertib or CXCR4 inhibitor AMD3100 in combination with anti-PD-L1 dramatically inhibited SOX18-mediated HCC progression and metastasis.

CONCLUSIONS

SOX18 promoted the accumulation of immunosuppressive TAMs and Tregs in the microenvironment by transactivating CXCL12 and PD-L1. CXCR4 inhibitor or TGFβR1 inhibitor in synergy with anti-PD-L1 represented a promising combination strategy to suppress HCC progression and metastasis.

MDSCs in bone metastasis: Mechanisms and therapeutic potential

Bone metastasis (BM) is a frequent complication associated with advanced cancer that significantly increases patient mortality. Myeloid-derived suppressor cells (MDSCs) play a pivotal role in BM progression by promoting angiogenesis, inhibiting immune responses, and inducing osteoclastogenesis. MDSCs induce immunosuppression through diverse mechanisms, including the generation of reactive oxygen species, nitric oxide, and immunosuppressive cytokines. Within the bone metastasis niche (BMN), MDSCs engage in intricate interactions with tumor, stromal, and bone cells, thereby establishing a complex regulatory network. The biological activities and functions of MDSCs are regulated by the microenvironment within BMN. Conversely, MDSCs actively contribute to microenvironmental regulation, thereby promoting BM development. A comprehensive understanding of the indispensable role played by MDSCs in BM is imperative for the development of novel therapeutic strategies. This review highlights the involvement of MDSCs in BM development, their regulatory mechanisms, and their potential as viable therapeutic targets.

Burning down the house: Pyroptosis in the tumor microenvironment of hepatocellular carcinoma

A high mortality rate makes hepatocellular carcinoma (HCC) a difficult cancer to treat. When surgery is not possible, liver cancer patients are treated with chemotherapy. However, HCC management and treatment are difficult. Sorafenib, which is a first-line treatment for hepatocellular carcinoma, initially slows disease progression. However, sorafenib resistance limits patient survival. Recent studies have linked HCC to programmed cell death, which has increased researcher interest in therapies targeting cell death. Pyroptosis, which is an inflammatory mode of programmed cell death, may be targeted to treat HCC. Pyroptosis pathways, executors, and effects are examined in this paper. This review summarizes how pyroptosis affects the tumor microenvironment (TME) in HCC, including the role of cytokines such as IL-1β and IL-18 in regulating immune responses. The use of chemotherapies and their ability to induce cancer cell pyroptosis as alternative treatments and combining them with other drugs to reduce side effects is also discussed. In conclusion, we highlight the potential of inducing pyroptosis to treat HCC and suggest ways to improve patient outcomes. Studies on cancer cell pyroptosis may lead to new HCC treatments.

Senescence-associated secretory phenotype (SASP) and uterine fibroids: Association with PD-L1 activation and collagen deposition

Uterine fibroids (or uterine leiomyoma, UFs) are one of the most prevalent benign uterine tumors with high proliferation and collagen synthesis capabilities. UFs are a significant worldwide health issue for women, affecting their physical and financial well-being. Risk factors for UFs include age, racial disparities, obesity, uterine infections, hormonal variation, and lifestyle (i.e., diet, exercise, stress, and smoking). Senescence and its associated secretory phenotypes (SASPs) are among the most salient changes accompanying the aging process. As a result, SASPs are suggested to be one of the major contributors to developing UFs. Interleukin 6 (IL-6), IL-8, IL-1, chemokine ligand 20 (CCL-20), and transforming growth factor-beta (TGF-β) are the most prominent SASPs associated with aging. In addition, different processes contribute to UFs such as collagen deposition and the changes in the immune microenvironment. Programmed death ligand 1 is a major player in the tumor immune microenvironment, which helps tumor cells evade immune attacks. This review focuses on the correlation of SASPs on two axes of tumor progression: immune suppression and collagen deposition. This review opens the door towards more investigations regarding changes in the UF immune microenvironment and age-UFs correlation and thus, a novel targeting approach for UF treatment.

Cancer stem cell-immune cell crosstalk in the tumor microenvironment for liver cancer progression

Crosstalk between cancer cells and the immune microenvironment is determinant for liver cancer progression. A tumor subpopulation called liver cancer stem cells (CSCs) significantly accounts for the initiation, metastasis, therapeutic resistance, and recurrence of liver cancer. Emerging evidence demonstrates that the interaction between liver CSCs and immune cells plays a crucial role in shaping an immunosuppressive microenvironment and determining immunotherapy responses. This review sheds light on the bidirectional crosstalk between liver CSCs and immune cells for liver cancer progression, as well as the underlying molecular mechanisms after presenting an overview of liver CSCs characteristic and their microenvironment. Finally, we discuss the potential application of liver CSCs-targeted immunotherapy for liver cancer treatment.

Macrophages and tumor-associated macrophages in the senescent microenvironment: From immunosuppressive TME to targeted tumor therapy

In-depth studies of the tumor microenvironment (TME) have helped to elucidate its cancer-promoting mechanisms and inherent characteristics. Cellular senescence, which acts as a response to injury and can the release of senescence-associated secretory phenotypes (SASPs). These SASPs release various cytokines, chemokines, and growth factors, remodeling the TME. This continual development of a senescent environment could be associated with chronic inflammation and immunosuppressive TME. Additionally, SASPs could influence the phenotype and function of macrophages, leading to the recruitment of tumor-associated macrophages (TAMs). This contributes to tumor proliferation and metastasis in the senescent microenvironment, working in tandem with immune regulation, angiogenesis, and therapeutic resistance. This comprehensive review covers the evolving nature of the senescent microenvironment, macrophages, and TAMs in tumor development. We also explored the links between chronic inflammation, immunosuppressive TME, cellular senescence, and macrophages. Moreover, we compiled various tumor-specific treatment strategies centered on cellular senescence and the current challenges in cellular senescence research. This study aimed to clarify the mechanism of macrophages and the senescent microenvironment in tumor progression and advance the development of targeted tumor therapies.

SLC7A11-ROS/αKG-AMPK axis regulates liver inflammation through mitophagy and impairs liver fibrosis and NASH progression

The changes of inflammation and metabolism are two features in nonalcoholic steatohepatitis (NASH). However, how they interact to regulate NASH progression remains largely unknown. Our works have demonstrated the importance of solute carrier family 7 member 11 (SLC7A11) in inflammation and metabolism. Nevertheless, whether SLC7A11 regulates NASH progression through mediating inflammation and metabolism is unclear. In this study, we found that SLC7A11 expression was increased in liver samples from patients with NASH. Upregulated SLC7A11 level was also detected in two murine NASH models. Functional studies showed that SLC7A11 knockdown or knockout had augmented steatohepatitis with suppression of inflammatory markers in mice. However, overexpression of SLC7A11 dramatically alleviated diet-induced NASH pathogenesis. Mechanically, SLC7A11 decreased reactive oxygen species (ROS) level and promoted α-ketoglutarate (αKG)/prolyl hydroxylase (PHD) activity, which activated AMPK pathway. Furthermore, SLC7A11 impaired expression of NLRP3 inflammasome components through AMPK-mitophagy axis. IL-1β release through NLRP3 inflammasome recruited myeloid cells and promoted hepatic stellate cells (HSCs) activation, which contributed to the progression of liver injury and fibrosis. Anti-IL-1β and anakinra might attenuate the hepatic inflammatory response evoked by SLC7A11 knockdown. Moreover, the upregulation of SLC7A11 in NASH was contributed by lipid overload-induced JNK-c-Jun pathway. In conclusions, SLC7A11 acts as a protective factor in controlling the development of NASH. Upregulation of SLC7A11 is protective by regulating oxidation, αKG and energy metabolism, decreasing inflammation and fibrosis.

Ferroptosis: A double-edged sword

Ferroptosis represents a form of programmed cell death that is propelled by iron-dependent lipid peroxidation, thereby being distinguished by the prominent features of iron accumulation and lipid peroxidation. Ferroptosis has been implicated in numerous physiological and pathological phenomena, with mounting indications that it holds significant implications for cancer and other medical conditions. On one side, it demonstrates anti-cancer properties by triggering ferroptosis within malignant cells, and on the other hand, it damages normal cells causing other diseases. Therefore, in this paper, we propose to review the paradoxical regulation of ferroptosis in tumors and other diseases. First, we introduce the development history, concept and mechanism of ferroptosis. The second part focuses on the methods of inducing ferroptosis in tumors. The third section emphasizes the utilization of ferroptosis in different medical conditions and strategies to inhibit ferroptosis. The fourth part elucidates the key contradictions in the control of ferroptosis. Finally, potential research avenues in associated domains are suggested.

The roles of cancer stem cell-derived secretory factors in shaping the immunosuppressive tumor microenvironment in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most prevalent malignancies worldwide and has a poor prognosis. Although immune checkpoint inhibitors have entered a new era of HCC treatment, their response rates are modest, which can be attributed to the immunosuppressive tumor microenvironment within HCC tumors. Accumulating evidence has shown that tumor growth is fueled by cancer stem cells (CSCs), which contribute to therapeutic resistance to the above treatments. Given that CSCs can regulate cellular and physical factors within the tumor niche by secreting various soluble factors in a paracrine manner, there have been increasing efforts toward understanding the roles of CSC-derived secretory factors in creating an immunosuppressive tumor microenvironment. In this review, we provide an update on how these secretory factors, including growth factors, cytokines, chemokines, and exosomes, contribute to the immunosuppressive TME, which leads to immune resistance. In addition, we present current therapeutic strategies targeting CSC-derived secretory factors and describe future perspectives. In summary, a better understanding of CSC biology in the TME provides a rational therapeutic basis for combination therapy with ICIs for effective HCC treatment.

Effect of genetic polymorphisms of interleukin-1 beta on the microscopic portal vein invasion and prognosis of hepatocellular carcinoma

BACKGROUND

Several studies have demonstrated a relationship between genetic polymorphisms of interleukin-1 beta (IL-1β) and cancer development; however, their influence on cancer prognosis is unknown. In the present study, we aimed to evaluate the impact of IL-1β single nucleotide polymorphisms on the hematogenous dissemination and prognosis of hepatocellular carcinoma.

METHODS

We conducted a retrospective cohort study including patients with hepatocellular carcinoma who underwent primary liver resection at our hospital between April 2015 and December 2018. The primary endpoints were overall and recurrence-free survival. Secondary endpoints were microscopic portal vein invasion and number of circulating tumor cells.

RESULTS

A total of 148 patients were included, 32 with rs16944 A/A genotype. A/A genotype was associated with microscopic portal vein invasion and number of circulating tumor cells (p = .03 and .04). In multivariate analysis, A/A genotype, alpha-fetoprotein level, and number of circulating tumor cells were associated with microscopic portal vein invasion (p = .01, .01, and <.01). A/A genotype, Child-Pugh B, and intraoperative blood loss were independent predictive factors for overall survival (p = .02, <.01, and <.01).

CONCLUSIONS

Our results indicate that the IL-1β rs16944 A/A genotype is involved in number of circulating tumor cells, microscopic portal vein invasion, and prognosis in HCC.

Interleukin-1β: Friend or foe for gastrointestinal cancers

Gastrointestinal (GI) cancer is a malignancy arising in the digestive system and accounts for approximately a third of increasing global cancer-related mortality, especially in the colorectum, esophagus, stomach, and liver. Interleukin-1β (IL-1β) is a leukocytic pyrogen recognized as a tumor progression-related cytokine. IL-1β secretion and maturation in inflammatory responses could be regulated by nuclear factor-kappaB-dependent expression of NLR family pyrin domain containing 3, inflammasome formation, and activation of IL-1 converting enzyme. Several studies have documented the pro-tumorigenic effects of IL-1β in tumor microenvironments, promoting proliferation and metastatic potential of cancer cells in vitro and tumorigenesis in vivo. The application of IL-1β inhibitors is also promising for targeted therapy development in some cancer types. However, as a leukocytic pro-inflammatory cytokine, IL-1β may also possess anti-tumorigenic effects and be type-specific in different cancers. This editorial discusses the up-to-date roles of IL-1β in GI cancers, including underlying mechanisms and downstream signaling pathways. Understanding and clarifying the roles of IL-1β would significantly benefit future therapeutic targeting and help improve therapeutic outcomes in patients suffering from GI cancer.

Macrophages Orchestrate the Liver Tumor Microenvironment

Liver cancer is one of the leading causes of cancer-related mortality. Hepatocellular carcinoma and cholangiocarcinoma are the most common types, and despite numerous advances, therapeutic options still remain poor for these cancer patients. Tumor development and progression strictly depend on a supportive tumor microenvironment (TME). Tumor-associated macrophages (TAMs) are the most abundant immune cells population within a tumorigenic liver; they sustain cancer cells' growth and invasiveness, and their presence is correlated with a poor prognosis. Furthermore, TAM cross-talk with cells and components of the TME promotes immunosuppression, a desmoplastic response, and angiogenesis. In this review, we summarize the latest advances in understanding TAM heterogeneity and function, with a particular focus on TAM modulation of the TME. We also discuss the potential of targeting macrophage subpopulations and how this is now being exploited in current clinical trials for the treatment of liver cancer.

Crosstalk between hypoxia-induced pyroptosis and immune escape in cancer: From mechanisms to therapy

Pyroptosis can be triggered through both canonical and non-canonical inflammasome pathways, involving the cleavage of gasdermin (GSDM) protein family members, like GSDMD and GSDME. The impact of pyroptosis on tumors is nuanced, because its role in regulating cancer progression and anti-tumor immunity may vary depending on the tumor type, stage, location, and immune status. However, pyroptosis cannot be simply categorized as promoting or inhibiting tumors based solely on whether it is acute or chronic in nature. The interplay between pyroptosis and cancer is intricate, with some evidence suggesting that chronic pyroptosis may facilitate tumor growth, while the acute induction of pyroptosis could stimulate anti-cancer immune responses. Tumor hypoxia activates hypoxia inducible factor (HIF) signaling to modulate pyroptosis and immune checkpoint expression. Targeting this hypoxia-pyroptosis-immune escape axis could be a promising therapeutic strategy. This review highlights the complex crosstalk between hypoxia, pyroptosis, and immune evasion in the TME.

Induction of the Inflammasome Pathway by Tyrosine Kinase Inhibitors Provides an Actionable Therapeutic Target for Hepatocellular Carcinoma

During the last decade, tyrosine kinase inhibitors (TKIs) sorafenib and regorafenib have been standard systemic treatments for advanced hepatocellular carcinoma (HCC). Previous data associated sorafenib with inflammasome activation. However, the role of the inflammasome in sorafenib and regorafenib signaling has not been described in liver cancer patients. For this purpose, we analyzed inflammasome-related transcriptomic changes in a murine HCC model. Our data confirmed inflammasome activation after both TKI treatments, sharing a similar pattern of increased gene expression. According to human database results, transcriptional increase of inflammasome genes is associated with poorer prognosis for male liver cancer patients, suggesting a sex-dependent role for inflammasome activation in HCC therapy. In biopsies of HCC and its surrounding tissue, we detected durable increases in the inflammasome activation pattern after sorafenib or regorafenib treatment in male patients. Further supporting its involvement in sorafenib action, inflammasome inhibition (MCC950) enhanced sorafenib anticancer activity in experimental HCC models, while no direct in vitro effect was observed in HCC cell lines. Moreover, activated human THP-1 macrophages released IL-1β after sorafenib administration, while 3D Hep3B spheres displayed increased tumor growth after IL-1β addition, pointing to the liver microenvironment as a key player in inflammasome action. In summary, our results unveil the inflammasome pathway as an actionable target in sorafenib or regorafenib therapy and associate an inflammasome signature in HCC and surrounding tissue with TKI administration. Therefore, targeting inflammasome activation, principally in male patients, could help to overcome sorafenib or regorafenib resistance and enhance the efficacy of TKI treatments in HCC.

Myeloid-derived suppressor cells in cancer: therapeutic targets to overcome tumor immune evasion

Paradoxically, tumor development and progression can be inhibited and promoted by the immune system. After three stages of immune editing, namely, elimination, homeostasis and escape, tumor cells are no longer restricted by immune surveillance and thus develop into clinical tumors. The mechanisms of immune escape include abnormalities in antitumor-associated immune cells, selection for immune resistance to tumor cells, impaired transport of T cells, and the formation of an immunosuppressive tumor microenvironment. A population of distinct immature myeloid cells, myeloid-derived suppressor cells (MDSCs), mediate immune escape primarily by exerting immunosuppressive effects and participating in the constitution of an immunosuppressive microtumor environment. Clinical trials have found that the levels of MDSCs in the peripheral blood of cancer patients are strongly correlated with tumor stage, metastasis and prognosis. Moreover, animal experiments have confirmed that elimination of MDSCs inhibits tumor growth and metastasis to some extent. Therefore, MDSCs may become the target of immunotherapy for many cancers, and eliminating MDSCs can help improve the response rate to cancer treatment and patient survival. However, a clear definition of MDSCs and the specific mechanism involved in immune escape are lacking. In this paper, we review the role of the MDSCs population in tumor development and the mechanisms involved in immune escape in different tumor contexts. In addition, we discuss the use of these cells as targets for tumor immunotherapy. This review not only contributes to a systematic and comprehensive understanding of the essential role of MDSCs in immune system reactions against tumors but also provides information to guide the development of cancer therapies targeting MDSCs.

Emerging trends of phytochemicals as ferroptosis modulators in cancer therapy

Ferroptosis, a novel form of regulated cell death characterized by dependence on iron and lipid peroxidation, has been implicated in a wide range of clinical conditions including neurological diseases, cardiovascular disorders, acute kidney failure, and various types of cancer. Therefore, it is critical to suppress cancer progression and proliferation. Ferroptosis can be triggered in cancer cells and some normal cells by synthetic substances, such as erastin, Ras-selective lethal small molecule-3, or clinical pharmaceuticals. Natural bioactive compounds are traditional drug discovery tools, and some have been therapeutically used as dietary additives or pharmaceutical agents against various malignancies. The fact that natural products have multiple targets and minimal side effects has led to notable advances in anticancer research. Research has indicated that ferroptosis can also be induced by natural compounds during cancer treatment. In this review, we focused on the most recent developments in emerging molecular processes and the significance of ferroptosis in cancer. To provide new perspectives on the future development of ferroptosis-related anticancer medications, we also provide a summary of the implications of natural phytochemicals in triggering ferroptosis through ROS production and ferritinophagy induction in a variety of malignancies.

Emerging role of ferroptosis in metabolic dysfunction-associated steatotic liver disease: revisiting hepatic lipid peroxidation

Metabolic dysfunction-associated steatohepatitis (MASH) is characterised by cell death of parenchymal liver cells which interact with their microenvironment to drive disease activity and liver fibrosis. The identification of the major death type could pave the way towards pharmacotherapy for MASH. To date, increasing evidence suggest a type of regulated cell death, named ferroptosis, which occurs through iron-catalysed peroxidation of polyunsaturated fatty acids (PUFA) in membrane phospholipids. Lipid peroxidation enjoys renewed interest in the light of ferroptosis, as druggable target in MASH. This review recapitulates the molecular mechanisms of ferroptosis in liver physiology, evidence for ferroptosis in human MASH and critically appraises the results of ferroptosis targeting in preclinical MASH models. Rewiring of redox, iron and PUFA metabolism in MASH creates a proferroptotic environment involved in MASH-related hepatocellular carcinoma (HCC) development. Ferroptosis induction might be a promising novel approach to eradicate HCC, while its inhibition might ameliorate MASH disease progression.

A programmed cell death-related gene signature to predict prognosis and therapeutic responses in liver hepatocellular carcinoma

BACKGROUND

Programmed cell death (PCD) functions critically in cancers and PCD-related genes are associated with tumor microenvironment (TME), prognosis and therapeutic responses of cancer patients. This study stratified hepatocellular carcinoma (HCC) patients and develop a prognostic model for predicting prognosis and therapeutic responses.

METHODS

Consensus clustering analysis was performed to subtype HCC patients in The Cancer Genome Atlas (TCGA) database. Differentially expressed genes (DEGs) among the subtypes were filtered and subjected to the least absolute shrinkage and selection operator (LASSO) regression analysis and univariate Cox regression analysis to filter prognostic genes. A PCD-related prognostic gene signature in TCGA was constructed and validated in ICGC-LIRI-JP and GSE14520 datasets. TME was analyzed using CIBERSORT, MCP-counter, TIMER and EPIC algorithms. Drug sensitivity was predicted by oncoPredict package. Spearman analysis was used to detect correlation.

RESULTS

Four molecular subtypes were categorized based on PCD-related genes. Subtype C1 showed the poorest prognosis, the most infiltration of Fibroblasts, dentritic cell (DC) and cancer-associated fibroblasts (CAFs), and the highest TIDE score. C4 had a better prognosis survival outcome, and lowest immune cell infiltration. The survival outcomes of C2 and C3 were intermediate. Next, a total of 69 co-DEGs were screened among the four subtypes and subsequently we identified five prognostic genes (MCM2, SPP1, S100A9, MSC and EPO) for developing the prognostic model. High-risk patients not only had unfavorable prognosis, higher clinical stage and grade, and more inflammatory pathway enrichment, but also possessed higher possibility of immune escape and were more sensitive to Cisplatin and 5. Fluorouracil. The robustness of the prognostic model was validated in external datasets.

CONCLUSION

This study provides new insights into clinical subtyping and the PCD-related prognostic signature may serve as a useful tool to predict prognosis and guide treatments for patients with HCC.

NLRP3 knockout in mice provided protection against Serratia marcescens-induced acute pneumonia by decreasing PD-L1 and PD-1 expression in macrophages

Antibiotic-resistant Serratia marcescens (Sm) is known to cause bloodstream infections, pneumonia, etc. The nod-like receptor family, pyrin domain-containing 3 (NLRP3), has been implicated in various lung infections. Yet, its role in Sm-induced pneumonia was not well understood. In our study, we discovered that deletion of Nlrp3 in mice significantly improved Sm-induced survival rates, reduced bacterial loads in the lungs, bronchoalveolar lavage fluid (BALF), and bloodstream, and mitigated the severity of acute lung injury (ALI) compared to wild-type (WT) mice. Mechanistically, we observed that 24 h post-Sm infection, NLRP3 inflammasome activation occurred, leading to gasdermin D NH2-terminal (GSDMD-NT)-induced pyroptosis in macrophages and IL-1β secretion. The NLRP3 or NLRP3 inflammasome influenced the expression PD-L1 and PD-1, as well as the count of PD-L1 or PD-1-expressing macrophages, alveolar macrophages, interstitial macrophages, PD-L1-expressing neutrophils, and the count of macrophage receptors with collagenous structure (MARCO)-expressing macrophages, particularly MARCO+ alveolar macrophages. The frequency of MARCO+ alveolar macrophages, PD-1 expression, particularly PD-1+ interstitial macrophages were negatively or positively correlated with the Sm load, respectively. Additionally, IL-1β levels in BALF correlated with three features of acute lung injury: histologic score, protein concentration and neutrophil count in BALF. Consequently, our findings suggest that Nlrp3 deletion offers protection agaisnt acute Sm pneumonia in mice by inhibiting inflammasome activation and reducing Sm infection-induced PD-L1/PD-1 or MARCO expression, particularly in macrophages. This highlights potential therapeutic targets for Sm and other gram-negative bacteria-induced acute pneumonia.

Disruption of MerTK increases the efficacy of checkpoint inhibitor by enhancing ferroptosis and immune response in hepatocellular carcinoma

Immune checkpoint inhibitors, particularly PD-1/PD-L1 blockades, have been approved for unresectable hepatocellular carcinoma (HCC). However, high resistance rates still limit their efficacy, highlighting the urgent need to understand the underlying mechanisms and develop strategies for overcoming the resistance. In this study, we demonstrate that HCC with high MER proto-oncogene tyrosine kinase (MerTK) expression exhibits anti-PD-1/PD-L1 resistance in two syngeneic mouse models and in patients who received anti-PD-1/PD-L1 therapy. Mechanistically, MerTK renders HCC resistant to anti-PD-1/PD-L1 by limiting ferroptosis with the upregulation of SLC7A11 via the ERK/SP1 pathway and facilitating the development of an immunosuppressive tumor microenvironment (TME) with the recruitment of myeloid-derived suppressor cells (MDSCs). Sitravatinib, an inhibitor of MerTK, sensitizes resistant HCC to anti-PD-L1 therapy by promoting tumor ferroptosis and decreasing MDSC infiltration into the TME. In conclusion, we find that MerTK could serve as a predictive biomarker for patient stratification and as a promising target to overcome anti-PD-1/PD-L1 resistance in HCC.

Centrosome amplification-related signature correlated with immune microenvironment and treatment response predicts prognosis and improves diagnosis of hepatocellular carcinoma by integrating machine learning and single-cell analyses

BACKGROUND

Centrosome amplification is a well-recognized oncogenic driver of tumor initiation and progression across a variety of malignancies and has been linked with tumor aggressiveness, metastasis, and adverse prognosis. Nevertheless, the significance of centrosome amplification in HCC is not well understood.

METHODS

The TCGA dataset was downloaded for centrosome amplification-related signature construction using the LASSO-penalized Cox regression algorithm, while the ICGC dataset was obtained for signature validation. Single-cell RNA sequencing from GSE149614 was analyzed to profile gene expression and the liver tumor niche.

RESULTS

A total of 134 centrosome amplification-related prognostic genes in HCC were detected and 6 key prognostic genes (SSX2IP, SPAG4, SAC3D1, NPM1, CSNK1D, and CEP55) among them were screened out to construct a signature with both high sensitivity and specificity in diagnosis and prognosis of HCC patients. The signature, as an independent factor, was associated with frequent recurrences, high mortality rates, advanced clinicopathologic features, and high vascular invasions. Moreover, the signature was intimately associated with cell cycle-related pathways and TP53 mutation profile, suggesting its underlying role in accelerating cell cycle progression and leading to liver cancer development. Meanwhile, the signature was also closely correlated with immunosuppressive cell infiltration and immune checkpoint expression, making it a vital immunosuppressive factor in the tumor microenvironment. Upon single-cell RNA sequencing, SSX2IP and SAC3D1 were found to be specially expressed in liver cancer stem-like cells, where they promoted cell cycle progression and hypoxia.

CONCLUSIONS

This study provided a direct molecular link of centrosome amplification with clinical characteristics, tumor microenvironment, and clinical drug-response, highlighting the critical role of centrosome amplification in liver cancer development and therapy resistance, thereby providing valuable insights into prognostic prediction and therapeutic response of HCC.

The Roles of Myeloid-Derived Suppressor Cells in Liver Disease

Liver disease-related mortality is a major cause of death worldwide. Hepatic innate and adaptive immune cells play diverse roles in liver homeostasis and disease. Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature myeloid cells. MDSCs can be broadly divided into monocytic MDSCs and polymorphonuclear or granulocytic MDSCs, and they functionally interact with both liver parenchymal and nonparenchymal cells, such as hepatocytes and regulatory T cells, to impact liver disease progression. The infiltration and activation of MDSCs in liver disease can be regulated by inflammatory chemokines and cytokines, tumor-associated fibroblasts, epigenetic regulation factors, and gut microbiota during liver injury and cancer. Given the pivotal roles of MDSCs in advanced liver diseases, they can be targeted to treat primary and metastatic liver cancer, liver generation, alcoholic and nonalcoholic liver disease, and autoimmune hepatitis. Currently, several treatments such as the antioxidant and anti-inflammatory agent berberine are under preclinical and clinical investigation to evaluate their therapeutic efficacy on liver disease and their effect on MDSC infiltration and function. Phenotypic alteration of MDSCs in different liver diseases that are in a model-dependent manner and lack special markers for distinct MDSCs are challenges for targeting MDSCs to treat liver disease. Multi-omics study is an option to uncover the features of disease-specific MDSCs and potential gene or protein targets for liver disease treatment. In summary, MDSCs play important roles in the pathogenesis and progression of liver disease by regulating both intrahepatic innate and adaptive immune responses.

SRSF10 facilitates HCC growth and metastasis by suppressing CD8+T cell infiltration and targeting SRSF10 enhances anti-PD-L1 therapy

BACKGROUND AND AIMS

RNA splicing is an essential step in regulating the gene posttranscriptional expression. Serine/arginine-rich splicing factors (SRSFs) are splicing regulators with vital roles in various tumors. Nevertheless, the expression patterns and functions of SRSFs in hepatocellular carcinoma (HCC) are not fully understood.

METHODS

Flow cytometry and immunofluorescent staining were used to determine the CD8+T cell infiltration. Orthotopic HCC model, lung metastasis model, DEN/CCl4 model, Srsf10△hep model, and Srsf10HepOE model were established to evaluate the role of SRSF10 in HCC and the efficacy of combination treatment.

RESULTS

SRSF10 was one of the most survival-relevant genes among SRSF members and was an independent prognostic factor for HCC. SRSF10 facilitated HCC growth and metastasis by suppressing CD8+T cell infiltration. Mechanistically, SRSF10 down-regulated the p53 protein by preventing the exon 6 skipping (exon 7 in mouse) mediated degradation of MDM4 transcript, thus inhibiting CD8+T cell infiltration. Elimination of CD8+T cells or overexpression of MDM4 removed the inhibitory role of SRSF10 knockdown in HCC growth and metastasis. SRSF10 also inhibited the IFNα/γ signaling pathway and promoted the HIF1α-mediated up-regulation of PD-L1 in HCC. Hepatocyte-specific SRSF10 deficiency alleviated the DEN/CCl4-induced HCC progression and metastasis, whereas hepatocyte-specific SRSF10 overexpression deteriorated these effects. Finally, SRSF10 knockdown enhanced the anti-PD-L1-mediated anti-tumor activity.

CONCLUSIONS

SRSF10 promoted HCC growth and metastasis by repressing CD8+T cell infiltration mediated by the MDM4-p53 axis. Furthermore, SRSF10 suppressed the IFNα/γ signaling pathway and induced the HIF1α signal mediated PD-L1 up-regulation. Targeting SRSF10 combined with anti-PD-L1 therapy showed promising efficacy.

A novel cholesterol metabolism-related ferroptosis pathway in hepatocellular carcinoma

BACKGROUND

Emerging studies have reported the contribution of cholesterol to hepatocellular carcinoma (HCC) progression. However, the specific role and mechanism of cholesterol metabolism on spontaneous and progressive HCC development from the point of view of ferroptosis are still worth exploring. The present study aimed to reveal a novel mechanism of cholesterol metabolism-related ferroptosis in hepatocellular carcinoma cells.

METHODS

Two microarray datasets (GSE25097, GSE22058) related to HCC were downloaded from Gene Expression Omnibus (GEO) datasets. Metabolomics analysis was performed by ultra performance liquid chromatography - tandem mass spectrometer (UPLC-MS/MS). The cholesterol-related proteins were downloaded from HMBD. Ferroptosis-related genes were extracted from FerrDb database. Data sets were separated into two groups. GSE25097 was used to identify ferroptosis-related genes, and GSE22058 was used to verify results. During these processes, chemical-protein interaction (CPI), protein-protein interaction (PPI), the Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were conducted. Multivariate logistic regression analysis was used to test the associated pathway.

RESULTS

We identified 8 differentially expressed ferroptosis-related genes (HAMP, PTGS2, IL1B, ALOX15B, CDKN2A, RRM2, NQO1 and KIF20A) and 4 differentially expressed cholesterol-related genes (LCAT, CH25H, CEL and CYP7A1). Furthermore, based on the predicted results with STITCH, we identified indomethacin and IL1B as the essential node for cholesterol-mediated ferroptosis in hepatocellular carcinoma cell. Multivariate logistic regression analysis showed the activities of plasma IL1B in liver cancer patients enrolled have been significantly affected by the level of plasma cholesterol (P < 0.001) and the test result of IL1B is a predictor variable causing the changes of serum Fe levels (P < 0.001).

CONCLUSIONS

Our findings shed new light on the association between cholesterol metabolism and ferroptosis in HCC, and suggest that IL1B is the necessary node for cholesterol to lead to ferroptosis process in HCC. Also, we identified the potential role of indomethacin in adjuvant therapy of HCC with complications of abnormal cholesterol metabolism.

The expression mechanism of programmed cell death 1 ligand 1 and its role in immunomodulatory ability of mesenchymal stem cells

Programmed cell death 1 ligand 1 (PD-L1) is an important immunosuppressive molecule, which inhibits the function of T cells and other immune cells by binding to the receptor programmed cell death-1. The PD-L1 expression disorder plays an important role in the occurrence, development, and treatment of sepsis or other inflammatory diseases, and has become an important target for the treatment of these diseases. Mesenchymal stem cells (MSCs) are a kind of pluripotent stem cells with multiple differentiation potential. In recent years, MSCs have been found to have a strong immunosuppressive ability and are used to treat various inflammatory insults caused by hyperimmune diseases. Moreover, PD-L1 is deeply involved in the immunosuppressive events of MSCs and plays an important role in the treatment of various diseases. In this review, we will summarize the main regulatory mechanism of PD-L1 expression, and discuss various biological functions of PD-L1 in the immune regulation of MSCs.

PURPL Promotes M2 Macrophage Polarization in Lung Cancer by Regulating RBM4/xCT Signaling

Lung cancer is the most common malignancy worldwide. Long non-coding RNA (lncRNA) p53 upregulated regulator of P53 levels (PURPL) is abnormally in various cancers. However, the reports on its roles in lung cancer are limited. The purpose of present study is to investigate the potentials of lncRNA PURPL in lung cancer. PURPL and mRNA expression was determined using real-time reverse transcriptase-polymerase chain reaction (RT-qPCR). The location of PURPL was detected using RNA fluorescence in situ hybridization (FISH) assay. Protein expression was detected using western blot. Cellular functions were determined using flow cytometry. The interaction between PURPL and RNA-binding motif 4 (RBM4) was confirmed using RNA immunoprecipitation (RIP) assay. PURPL was overexpressed in lung cancer cells and patients. Overexpressed PURPL promoted M2 macrophage polarization and suppressed ferroptosis. Additionally, PURPL maintained the mRNA stability of cystine glutamate reverse transporter (xCT) via regulating RBM4. xCT knockdown antagonized the effects of overexpressed PURPL and inhibited M2 macrophage polarization via inducing macrophage ferroptosis. PURPL/RBM4/xCT axis promoted M2 macrophage polarization in lung cancer. Therefore, PURPL may be a potential target of lung cancer.

Interplay between inflammasomes and PD-1/PD-L1 and their implications in cancer immunotherapy

The inflammasomes play crucial roles in inflammation and cancer development, while the PD-1/PD-L1 pathway is critical for immune suppression in the tumor microenvironment (TME). Recent research indicates a reciprocal regulatory relationship between inflammasomes and PD-1/PD-L1 signaling in cancer development and PD-1 blockade treatment. By activating in diverse cells in tumor tissues, inflammasome upregulates PD-L1 level in the TME. Moreover, the regulation of PD-1/PD-L1 activity by inflammasome activation involves natural killer cells, tumor-associated macrophages and myeloid-derived suppressor cells. Conversely, PD-1 blockade can activate the inflammasome, potentially influencing treatment outcomes. The interplay between inflammasomes and PD-1/PD-L1 has profound and intricate effects on cancer development and treatment. In this review, we discuss the crosstalk between inflammasomes and PD-1/PD-L1 in cancers, exploring their implications for tumorigenesis, metastasis and immune checkpoint inhibitor (ICI) resistance. The combined therapeutic strategies targeting both inflammasomes and checkpoint molecules hold promising potential as treatments for cancer.

Radix Bupleuri-Radix Paeoniae Alba Inhibits the Development of Hepatocellular Carcinoma through Activation of the PTEN/PD-L1 Axis within the Immune Microenvironment

OBJECTIVE

This study investigated how Radix Bupleuri-Radix Paeoniae Alba (BP) was active against hepatocellular carcinoma (HCC).

METHODS

Traditional Chinese medicine systems pharmacology (TCMSP) database was employed to determine the active ingredients of BP and potential targets against HCC. Molecular docking analysis verified the binding activity of PTEN with BP ingredients. H22 cells were used to establish an HCC model in male balb/c mice. Immunofluorescence staining, immunohistochemistry, flow cytometry, western blotting, enzyme-linked immunosorbent assay, and real-time quantitative PCR were used to study changes in proliferation, apoptosis, PTEN levels, inflammation, and T-cell differentiation in male balb/c mice.

RESULTS

The major active ingredients in BP were found to be quercetin, kaempferol, isorhamnetin, stigmasterol, and beta-sitosterol. Molecular docking demonstrated that these five active BP ingredients formed a stable complex with PTEN. BP exhibited an anti-tumor effect in our HCC mouse model. BP was found to increase the CD8+ and IFN-γ+/CD4+ T cell levels while decreasing the PD-1+/CD8+ T and Treg cell levels in HCC mice. BP up-regulated the IL-6, IFN-γ, and TNF-α levels but down-regulated the IL-10 levels in HCC mice. After PTEN knockdown, BP-induced effects were abrogated.

CONCLUSION

BP influenced the immune microenvironment through activation of the PTEN/PD-L1 axis, protecting against HCC.

The current status and future of PD-L1 in liver cancer

The application of immunotherapy in tumor, especially immune checkpoint inhibitors (ICIs), has played an important role in the treatment of advanced unresectable liver cancer. However, the efficacy of ICIs varies greatly among different patients, which has aroused people's attention to the regulatory mechanism of programmed death ligand-1 (PD-L1) in the immune escape of liver cancer. PD-L1 is regulated by multiple levels and signaling pathways in hepatocellular carcinoma (HCC), including gene variation, epigenetic inheritance, transcriptional regulation, post-transcriptional regulation, and post-translational modification. More studies have also found that the high expression of PD-L1 may be the main factor affecting the immunotherapy of liver cancer. However, what is the difference of PD-L1 expressed by different types of cells in the microenvironment of HCC, and which type of cells expressed PD-L1 determines the effect of tumor immunotherapy remains unclear. Therefore, clarifying the regulatory mechanism of PD-L1 in liver cancer can provide more basis for liver cancer immunotherapy and combined immune treatment strategy. In addition to its well-known role in immune regulation, PD-L1 also plays a role in regulating cancer cell proliferation and promoting drug resistance of tumor cells, which will be reviewed in this paper. In addition, we also summarized the natural products and drugs that regulated the expression of PD-L1 in HCC.

The role of tumor-associated macrophages in hepatocellular carcinoma progression: A narrative review

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in the world, with complex etiology and mechanism, and a high mortality rate. Tumor-associated macrophages (TAMs) are an important part of the HCC tumor microenvironment. Studies in recent years have shown that TAMs are involved in multiple stages of HCC and are related to treatment and prognosis in HCC. The specific mechanisms between TAMs and HCC are gradually being revealed. This paper reviews recent advances in the mechanisms associated with TAMs in HCC, concentrating on an overview of effects of TAMs on drug resistance in HCC and the signaling pathways linked with HCC, providing clues for the treatment and prognosis determination of HCC.

NLRP3/IL-1β induced myeloid-derived suppressor cells recruitment and PD-L1 upregulation promotes oxaliplatin resistance of hepatocellular carcinoma

Oxaliplatin is commonly used as the first-line chemotherapeutic agent for advanced hepatocellular carcinoma (HCC). Unfortunately, the acquired resistance, limits the effectiveness of oxaliplatin and the underlying mechanisms remain unknown. Therefore, we explored the role of NOD-like receptor protein 3 (NLRP3)/IL-1β in mediating oxaliplatin resistance in HCC. We observed that NLRP3/IL-1β expression was much higher in oxaliplatin-resistant HCC cells. To further understand its impact on drug resistance, we knocked down NLRP3 and observed that it sensitized HCC cells to the growth-inhibitory effects of oxaliplatin and induced cell apoptosis. NLRP3/IL-1β overexpressing tumor cells also attracted polymorphonuclear myeloid-derived suppressor cells. Using mouse models, we demonstrated that NLRP3/IL-1β inhibition by short hairpin RNA or MCC950 effectively overcame oxaliplatin resistance. Furthermore, NLRP3/IL-1β inhibition resulted in reduced expression of PD-L1. We also found that PD-L1 antibody combined with NLRP3/IL-1β blockade displayed significant antitumor effect in HCC. Overall, our study provides compelling evidence supporting the essential role of NLRP3/IL-1β in conferring resistance to oxaliplatin and reshaping the immunosuppressive microenvironment in HCC. Targeting NLRP3/IL-1β presents a potential therapeutic target for overcoming oxaliplatin resistance and reshaping microenvironment of HCC.

Comprehensive Analysis of Disulfidptosis-Related LncRNAs in Molecular Classification, Immune Microenvironment Characterization and Prognosis of Gastric Cancer

BACKGROUND

Disulfidptosis is a novel form of programmed cell death that unveils promising avenues for the exploration of tumor treatment modalities. Gastric cancer (GC) is a malignant tumor characterized by high incidence and mortality rate. However, there has been no systematic study of disulfidptosis-related long noncoding RNAs (DRLs) signature in GC patients.

METHODS

The lncRNA expression profiles containing 412 GC samples were acquired from the Cancer Genome Atlas (TCGA) database. Differential expression analysis was performed alongside Pearson correlation analysis to identify DRLs. Prognostically significant DRLs were further screened using univariate COX regression analysis. Subsequently, LASSO regression and multifactorial COX regression analyses were employed to establish a risk signature composed of DRLs that exhibit independent prognostic significance. The predictive value of this risk signature was further validated in a test cohort. The ESTIMATE, CIBERSORT and ssGSEA methodologies were utilized to investigate the tumor immune microenvironment of GC populations with different DRLs profiles. Finally, the correlation between DRLs and various GC drug responses was explored.

RESULTS

We established a prognostic signature comprising 12 disulfidptosis-related lncRNAs (AC110491.1, AL355574.1, RHPN1-AS1, AOAH-IT1, AP001065.3, MEF2C-AS1, AC016394.2, LINC00705, LINC01952, PART1, TNFRSF10A-AS1, LINC01537). The Kaplan-Meier survival analysis revealed that patients in the high-risk group exhibited a poor prognosis. Both univariate and multivariate COX regression models demonstrated that the DRLs signature was an independent prognostic indicator in GC patients. Furthermore, the signature exhibited accurate predictions of survival at 1-, 3- and 5- years with the area under the curve (AUC) values of 0.708, 0.689 and 0.854, respectively. In addition, we also observed significant associations between the DRLs signature and various clinical variables, distinct immune landscape and drug sensitivity profiles in GC patients. The low-risk group patients may be more likely to benefit from immunotherapy and chemotherapy.

CONCLUSIONS

Our study investigated the role and potential clinical implications of DRLs in GC. The risk model constructed by DRLs demonstrated high accuracy in predicting the survival outcomes of GC and improving the treatment efficacy for GC patients.

Blockage of CacyBP inhibits macrophage recruitment and improves anti-PD-1 therapy in hepatocellular carcinoma

BACKGROUND

Despite remarkable advancements in cancer immunotherapy, the overall response rate to anti-programmed cell death-1 (anti-PD-1) therapy in hepatocellular carcinoma (HCC) patients remains low. Our previous study has demonstrated the critical role of CacyBP/SIP (Calcyclin-Binding Protein and Siah-1 Interacting Protein) as a regulator of HCC development and progression. However, the possible impact of CacyBP on the tumor immune microenvironment has not yet been clarified.

METHODS

The expressions of CacyBP and Myd88 in HCC cell lines and tissues was detected by bioinformatics analysis, real-time quantitative PCR, western blotting and immunohistochemistry. The interaction between CacyBP and Myd88 was measured using co-immunoprecipitation and immunofluorescence. In vitro and in vivo assays were used to investigate the regulation of CacyBP on tumor-associated macrophages (TAMs).

RESULTS

We identified that CacyBP was positively correlated with Myd88, a master regulator of innate immunity, and Myd88 was a novel binding substrate downstream of CacyBP in HCC. Additionally, CacyBP protected Myd88 from Siah-1-mediated proteasome-dependent degradation by competitively binding to its Toll/interleukin-1 receptor (TIR) domain. Inhibition of CacyBP-Myd88 signaling subsequently diminished HDAC1-mediated H3K9ac and H3K27ac modifications on the CX3CL1 promoter and reduced its transcription and secretion in HCC cells. Moreover, by using in vitro and in vivo strategies, we demonstrated that depletion of CacyBP impaired the infiltration of TAMs and the immunosuppressive state of the tumor microenvironment, further sensitizing HCC-bearing anti-PD-1 therapy.

CONCLUSIONS

Our findings suggest that targeting CacyBP may be a novel treatment strategy for improving the efficacy of anti-PD-1 immunotherapy in HCC.

The development and experimental validation of hypoxia-related long noncoding RNAs prognostic signature in predicting prognosis and immunotherapy of cutaneous melanoma

Cutaneous melanoma (CM) is widely acknowledged as a highly aggressive form of malignancy that is associated with a considerable degree of morbidity and poor prognosis. Despite this recognition, the precise role of hypoxia-related long noncoding RNAs (HRLs) in the pathogenesis of CM remains an area of active research. This study sought to elucidate the contribution of HRLs in CM by conducting a thorough screening and extraction of hypoxia-related genes (HRGs). In particular, we conducted univariate and multivariate Cox regression analyses to assess the independence of the prognostic signature of HRLs. Our results demonstrated that a novel risk model could be established based on five prognostic HRLs. Remarkably, patients with low-risk scores exhibited significantly higher overall survival rates compared to their high-risk counterparts, as confirmed by Kaplan-Meier survival analysis. Furthermore, we utilized consensus clustering analysis to categorize CM patients into two distinct subtypes, which revealed marked differences in their prognosis and immune infiltration landscapes. Our nomogram results confirmed that the HRLs prognostic signature served as an independent prognostic indicator, offering an accurate evaluation of the survival probability of CM patients. Notably, our findings from ESTIMATE and ssGSEA analyses highlighted significant disparities in the immune infiltration landscape between low- and high-risk groups of CM patients. Additionally, IPS and TIDE results suggested that CM patients in different risk subtypes may exhibit favorable responses to immunotherapy. Enrichment analysis and GSVA results indicated that immune-related signaling pathways may mediate the role of HRLs in CM. Finally, our tumor mutation burden (TMB) results indicated that patients with low-risk scores had a higher TMB status. In summary, the establishment of a risk model based on HRLs in this study provided an accurate prognostic prediction and correlated with the immune infiltration landscape of CM, thereby providing novel insights for the future clinical management of this disease.

Targeting the Heterogeneous Tumour-Associated Macrophages in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a prevalent and aggressive cancer that comprises a complex tumour microenvironment (TME). Tumour-associated macrophages (TAMs) are one of the most abundant immune cells present in the TME, and play a key role both in the development and in the progression of HCC. Thus, TAM-based immunotherapy has been presented as a promising strategy to complement the currently available therapies for HCC treatment. Among the novel approaches focusing on TAMs, reprogramming their functional state has emerged as a promising option for targeting TAMs as an immunotherapy in combination with the currently available treatment options. Nevertheless, a further understanding of the immunobiology of TAMs is still required. This review synthesizes current insights into the heterogeneous nature of TAMs in HCC and describes the mechanisms behind their pro-tumoural polarization focusing the attention on their interaction with HCC cells. Furthermore, this review underscores the potential involvement of TAMs' reprogramming in HCC therapy and highlights the urgency of advancing our understanding of these cells within the dynamic landscape of HCC.

Glutamine metabolism in tumor metastasis: Genes, mechanisms and the therapeutic targets

Cancer cells frequently change their metabolism from aerobic glycolysis to lipid metabolism and amino acid metabolism to adapt to the malignant biological behaviours of infinite proliferation and distant metastasis. The significance of metabolic substances and patterns in tumour cell metastasis is becoming increasingly prominent. Tumour metastasis involves a series of significant steps such as the shedding of cancer cells from a primary tumour, resistance to apoptosis, and colonisation of metastatic sites. However, the role of glutamine in these processes remains unclear. This review summarises the key enzymes and transporters involved in glutamine metabolism that are related to the pathogenesis of malignant tumour metastasis. We also list the roles of glutamine in resisting oxidative stress and promoting immune escape. Finally, the significance of targeting glutamine metabolism in inhibiting tumour metastasis was proposed, research in this field improving our understanding of amino acid metabolism rewiring and simultaneously bringing about new and exciting therapeutic prospects.

Progress in research on the role played by myeloid-derived suppressor cells in liver diseases

Myeloid-derived suppressor cells (MDSCs) refer to a group of immature myeloid cells with potent immunosuppressive capacity upon activation by pathological conditions. Because of their potent immunosuppressive ability, MDSCs have garnered extensive attention in the past few years in the fields of oncology, infection, chronic inflammation and autoimmune diseases. Research on MDSCs in liver diseases has gradually increased, and their potential therapeutic roles will be further explored. This review presents a summary of the involvement and the role played by MDSCs in liver diseases, thus identifying their potential targets for the treatment of liver diseases and providing new directions for liver disease-related research.

The Tian-Men-Dong decoction suppresses the tumour-infiltrating G-MDSCs via IL-1β-mediated signalling in lung cancer

ETHNOPHARMACOLOGICAL RELEVANCE

The traditional Chinese medicine (TCM) Tian-Men-Dong decoction (TD) has been able to effectively treat lung cancer in China for thousands of years. TD improves the quality of life in lung cancer patients by promoting nourishment of yin and reducing dryness, clearing the lung and removing toxins. Pharmacological studies show that TD contains active antitumour ingredients, but its underlying mechanism remains unknown.

AIM OF THE STUDY

This study aims at exploring potential mechanisms of TD in the treatment of lung cancer by regulating granulocytic-myeloid-derived suppressor cells (G-MDSCs).

MATERIALS AND METHODS

An orthotopic lung cancer mouse model was generated by intrapulmonary injection with LLC-luciferase cells in immunocompetent C57BL/6 mice or immunodeficient nude mice. TD/saline was orally administered once to the model mice daily for 4 weeks. Live imaging was conducted to monitor tumour growth. Immune profiles were detected by flow cytometry. H&E and ELISA were applied to test the cytotoxicity of the TD treatment. RT-qPCR and western blotting were performed to detect apoptosis-related proteins in G-MDSCs. A neutralizing antibody (anti-Ly6G) was utilized to exhaust the G-MDSCs via intraperitoneal injection. G-MDSCs were adoptively transferred from wild-type tumour-bearing mice. Immunofluorescence, TUNEL and Annexin V/PI staining were conducted to analyse apoptosis-related markers. A coculture assay of purified MDSCs and T cells labelled with CFSE was performed to test the immunosuppressive activity of MDSCs. The presence of TD/IL-1β/TD + IL-1β in purified G-MDSCs cocultured with the LLC system was used for ex vivo experiments to detect IL-1β-mediated apoptosis of G-MDSCs.

RESULTS

TD prolonged the survival of immune competent C57BL/6 mice in an orthotopic lung cancer model, but did not have the same effect in immunodeficient nude mice, indicating that its antitumour properties of TD are exerted by regulating immunity. TD induced G-MDSC apoptosis via the IL-1β-mediated NF-κB signalling cascade leading to effectively weaken the immunosuppressive activity of G-MDSCs and promote CD8⁺ T-cell infiltration, which was supported by both the depletion and adoptive transfer of G-MDSCs assays. In addition, TD also showed minimal cytotoxicity both in vivo and in vitro.

CONCLUSION

This study reveals for the first time that TD, a classic TCM prescription, is able to regulate G-MDSC activity and trigger its apoptosis via the IL-1β-mediated NF-κB signalling pathway, reshaping the tumour microenvironment and demonstrating antitumour effects. These findings provide a scientific foundation the clinical treatment of lung cancer with TD.

Mechanisms of tumor-associated macrophages affecting the progression of hepatocellular carcinoma

Tumor-associated macrophages (TAMs) are essential components of the immune cell stroma of hepatocellular carcinoma. TAMs originate from monocytic myeloid-derived suppressor cells, peripheral blood monocytes, and kupffer cells. The recruitment of monocytes to the HCC tumor microenvironment is facilitated by various factors, leading to their differentiation into TAMs with unique phenotypes. TAMs can directly activate or inhibit the nuclear factor-κB, interleukin-6/signal transducer and signal transducer and activator of transcription 3, Wnt/β-catenin, transforming growth factor-β1/bone morphogenetic protein, and extracellular signal-regulated kinase 1/2 signaling pathways in tumor cells and interact with other immune cells via producing cytokines and extracellular vesicles, thus affecting carcinoma cell proliferation, invasive and migratory, angiogenesis, liver fibrosis progression, and other processes to participate in different stages of tumor progression. In recent years, TAMs have received much attention as a prospective treatment target for HCC. This review describes the origin and characteristics of TAMs and their mechanism of action in the occurrence and development of HCC to offer a theoretical foundation for further clinical research of TAMs.

Ferroptosis as a potential target for cancer therapy

Ferroptosis is a recently discovered essential type of cell death that is mainly characterized by iron overload and lipid peroxidation. Emerging evidence suggests that ferroptosis is a double-edged sword in human cancer. However, the precise underlying molecular mechanisms and their differential roles in tumorigenesis are unclear. Therefore, in this review, we summarize and briefly present the key pathways of ferroptosis, paying special attention to the regulation of ferroptosis as well as its dual role as an oncogenic and as a tumor suppressor event in various human cancers. Moreover, multiple pharmacological ferroptosis activators are summarized, and the prospect of targeting ferroptosis in cancer therapy is further elucidated.

Mitochondrial general control of amino acid synthesis 5 like 1 promotes nonalcoholic steatohepatitis development through ferroptosis-induced formation of neutrophil extracellular traps

BACKGROUND

Mitochondria play central roles in metabolic diseases including nonalcoholic steatohepatitis (NASH). However, how mitochondria regulate NASH progression remains largely unknown. Our previous findings demonstrate that mitochondrial general control of amino acid synthesis 5 like 1 (GCN5L1) is associated with mitochondrial metabolism. Nevertheless, the roles of GCN5L1 in NASH are unclear.

AIMS AND METHODS

The GCN5L1 expression was detected in the fatty livers of NASH patients and animals. Hepatocyte-specific GCN5L1 deficiency or overexpression mice were used to induce NASH models by feeding with a high-fat/high-cholesterol or methionine-choline deficient diet. The molecular mechanisms underlying GCN5L1-regulated NASH were further explored and verified in mice.

RESULTS AND CONCLUSIONS

GCN5L1 expression was increased in NASH patients. Upregulated GCN5L1 level was also illustrated in NASH mice. Mice with hepatocyte-specific GCN5L1 conditional knockout improved the inflammatory response compared to GCN5L1flox/flox mice. However, overexpression of mitochondrial GCN5L1 augmented the inflammatory response. Mechanically, GCN5L1 acetylated CypD and enhanced its binding with ATP5B, which induced the opening of mitochondrial permeability transition pores and the release of mitochondrial ROS into the cytoplasm. The increased ROS promoted ferroptosis of hepatocytes and induced accumulation of high mobility group box 1 in the microenvironment, which recruited neutrophils and induced the generation of neutrophil extracellular traps (NETs). NETs block impaired GCN5L1-induced NASH progression. Furthermore, the upregulation of GCN5L1 in NASH was contributed by lipid overload-induced endoplasmic reticulum stress. Together, mitochondrial GCN5L1 has a vital function in promoting NASH progression by regulating oxidative metabolism and the hepatic inflammatory microenvironment. Thus, GCN5L1 might be a potential intervention target in NASH treatment.

Harnessing function of EMT in hepatocellular carcinoma: From biological view to nanotechnological standpoint

Management of cancer metastasis has been associated with remarkable reduction in progression of cancer cells and improving survival rate of patients. Since 90% of mortality are due to cancer metastasis, its suppression can improve ability in cancer fighting. The EMT has been an underlying cause in increasing cancer migration and it is followed by mesenchymal transformation of epithelial cells. HCC is the predominant kind of liver tumor threatening life of many people around the world with poor prognosis. Increasing patient prognosis can be obtained via inhibiting tumor metastasis. HCC metastasis modulation by EMT and HCC therapy by nanoparticles are discussed here. First of all, EMT happens during progression and advanced stages of HCC and therefore, its inhibition can reduce tumor malignancy. Moreover, anti-cancer compounds including all-trans retinoic acid and plumbaging, among others, have been considered as inhibitors of EMT. The EMT association with chemoresistance has been evaluated. Moreover, ZEB1/2, TGF-β, Snail and Twist are EMT modulators in HCC and enhancing cancer invasion. Therefore, EMT mechanism and related molecular mechanisms in HCC are evaluated. The treatment of HCC has not been only emphasized on targeting molecular pathways with pharmacological compounds and since drugs have low bioavailability, their targeted delivery by nanoparticles promotes HCC elimination. Moreover, nanoparticle-mediated phototherapy impairs tumorigenesis in HCC by triggering cell death. Metastasis of HCC and even EMT mechanism can be suppressed by cargo-loaded nanoparticles.

The role of myeloid-derived suppressor cells in liver cancer

MDSCs are immature myeloid immune cells, which accumulate in models of liver cancer to reduce effector immune cell activity, contribute to immune escape and treatment resistance. The accumulation of MDSCs suppresses the role of CTL and the killing effects of NK cells, induces the accumulation of Treg cells, and blocks the antigen presentation of DCs, thus promoting the progression of liver cancer. Recently, immunotherapy has emerged a valuable approach following chemoradiotherapy in the therapy of advanced liver cancer. A considerable increasing of researches had proved that targeting MDSCs has become one of the therapeutic targets to enhance tumor immunity. In preclinical study models, targeting MDSCs have shown encouraging results in both alone and in combination administration. In this paper, we elaborated immune microenvironment of the liver, function and regulatory mechanisms of MDSCs, and therapeutic approaches to target MDSCs. We also expect these strategies to supply new views for future immunotherapy for the treatment of liver cancer.

Roles of tumor-associated macrophages in anti-PD-1/PD-L1 immunotherapy for solid cancers

In recent years, tumor immunotherapy has made significant progress. However, tumor immunotherapy, particularly immune checkpoint inhibitors (e.g., PD-1/PD-L1 inhibitors), benefits only a tiny proportion of patients in solid cancers. The tumor microenvironment (TME) acts a significant role in tumor immunotherapy. Studies reported that tumor-associated macrophages (TAMs), as one of the main components of TME, seriously affected the therapeutic effect of PD-1/PD-L1 inhibitors. In this review, we analyzed TAMs from epigenetic and single-cell perspectives and introduced the role and mechanisms of TAMs in anti-programmed death protein 1(anti-PD-1) therapy. In addition, we summarized combination regimens that enhance the efficacy of tumor PD-1/PD-L1 inhibitors and elaborated on the role of the TAMs in different solid cancers. Eventually, the clinical value of TAMs by influencing the therapeutic effect of tumor PD-1/PD-L1 inhibitors was discussed. These above are beneficial to elucidate poor therapeutic effect of PD-1/PD-L1 inhibitors in solid tumors from the point of view of TAMs and explore the strategies to improve its objective remission rate of solid cancers.

Identification of a novel plasma metabolite panel as diagnostic biomarker for hepatocellular carcinoma

BACKGROUND AND AIMS

Metabolic reprogramming is one of the hallmarks of cancer. Hepatocellular carcinoma (HCC) is one of the most lethal malignancy camcer, but the early diagnosis of HCC remains difficult. In this study, we searched for potential plasma metabolite biomarkers of HCC.

METHODS

A total of plasma samples of 104 HCC, 76 cirrhosis and 10 healthy subjects were assessed and validated through Gas chromatography-Mass spectrometry. Receiver-operating characteristic curves (ROC) combined with multivariate statistical analyses were used to assess the diagnostic performance of metabolites and combinations.

RESULTS

10 metabolites in screening cohort were significantly changed in the plasma of HCC patients. Multivariate logistic regression analysis of candidate metabolites in validation cohort showed that N-formylglycine, oxoglutaric acid, citrulline and heptaethylene glycol could distinguish HCC from cirrhosis. The combination of these four metabolites showed a better performance than AFP with the Area Under the Curve (AUC), sensitivity, specificity as 0.940, 84.00%, 97.56%, respectively. In further, the panel of N-formylglycine, heptaethylene glycol and citrulline can more effectively discriminate early stage HCC from cirrhosis than AFP (AUC: 0.835 vs. 0.634). Finally, heptaethylene glycol could significantly inhibit the proliferation, migration and invasion of HCC cells in vitro.

CONCLUSION

The combination of plasma N-formylglycine, oxoglutaric acid, citrulline, and heptaethylene glycol can be an efficient novel diagnostic biomarker for HCC.

AKR1C3 suppresses ferroptosis in hepatocellular carcinoma through regulation of YAP/SLC7A11 signaling pathway

AKR1C3 is frequently overexpressed and it is a validated therapeutic target in various tumors including hepatocellular carcinoma (HCC). Our previous study showed that AKR1C3 facilitated HCC proliferation and metastasis by forming a positive feedback loop of AKR1C3-NF-κB-STAT3. Ferroptosis is a form of iron-dependent cell death driven by iron-dependent accumulation of lipid reactive oxygen species and plays an important role in tumor suppression. However, little is known about the role of AKR1C3 in ferroptosis susceptibility. In this study, we found that knockdown of AKR1C3 potently enhanced the sensitivity of HCC cells to ferroptosis inducers both in vitro and in vivo. Overexpression of AKR1C3 protected against ferroptosis in HCC cells. Mechanistically, AKR1C3 regulated ferroptosis through YAP/SLC7A11 signaling in HCC. AKR1C3 knockdown led to a decrease in YAP nuclear translocation, resulted in the inhibition of cystine transporter SLC7A11, and a subsequent increase in the intracellular levels of ferrous iron and ultimately ferroptosis. Moreover, we found that the combination of AKR1C3 and SLC7A11 was a strong predictor of poor prognosis in HCC. Collectively, these findings identify a novel role of AKR1C3 in ferroptosis, and highlighting a candidate therapeutic target to potentially improve the effect of ferroptosis-based antitumor therapy.

Periostin deficiency reduces PD-1+ tumor-associated macrophage infiltration and enhances anti-PD-1 efficacy in colorectal cancer

Periostin, a multifunctional extracellular protein, plays an important role in inflammatory disorders and tumorigenesis. Our previous work has demonstrated that periostin deficiency inhibits colorectal cancer (CRC) progression. Here, we aim to clarify the role of periostin in the immune microenvironment of CRC. We find that periostin deficiency significantly decreases the infiltration of programmed death receptor 1 (PD-1)+ tumor-associated macrophages (TAMs) in CRC tissues. Periostin promotes the expression of PD-1 on TAMs by integrin-ILK-nuclear factor κB (NF-κB) signaling, and PD-1+ TAMs produce interleukin-6 (IL-6) and interferon γ (IFN-γ) to induce the expression of PD-L1 on colorectal tumor cells. Moreover, combined inhibition of periostin and PD-1 significantly suppresses CRC progression compared with the inhibition of periostin or PD-1 alone. In summary, our results suggest that periostin deficiency reduces the infiltration of PD-1+ TAMs and enhances the efficacy of anti-PD-1 treatment in CRC.

S100A9 promotes tumor-associated macrophage for M2 macrophage polarization to drive human liver cancer progression: An in vitro study

Tumor-associated macrophages (TAMs) and M2 macrophage polarization have been documented for their implication in various malignancies, but their implication in liver cancer remains to be determined. This study is intended to explore the effect of S100A9 regulated TAMs and macrophage polarization in liver cancer progression. THP-1 cells were induced to differentiate into M1 and M2 macrophages, which were then cultured in liver cancer cell conditioned culture medium before the M1 and M2 macrophages were identified by measuring biomarkers using real-time polymerase chain reaction. The differential expressed genes in macrophages in Gene Expression Omnibus (GEO) databases were screened. S100A9 overexpression and knockdown plasmid were transfected into macrophages to determine the effect of S100A9 on M2 macrophage polarization of TAMs and on proliferation ability of liver cancer cells. The proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) abilities of liver cancer co-cultured with TAMs. M1 and M2 macrophages were successfully induced and liver cancer cell conditioned culture medium can increase polarization of macrophages into M2 macrophages, in which elevated expression of S100A9 was detected. Data in GEO database showed that tumor microenvironment (TME) upregulated S1000A9 expression. Suppression on S1000A9 can significantly suppress M2 macrophage polarization. TAM can provide the necessary microenvironment for liver cancer cells, HepG2 and MHCC97H by increasing cell proliferation, migration, and invasion ability, while suppression on S1000A9 can reverse this expression pattern. Suppression on S100A9 expression can regulate M2 macrophage polarization of TAMs to suppress the progression of liver cancer.

The contradictory roles of macrophages in non-alcoholic fatty liver disease and primary liver cancer-Challenges and opportunities

Chronic liver diseases from varying etiologies generally lead to liver fibrosis and cirrhosis. Among them, non-alcoholic fatty liver disease (NAFLD) affects roughly one-quarter of the world population, thus representing a major and increasing public health burden. Chronic hepatocyte injury, inflammation (non-alcoholic steatohepatitis, NASH) and liver fibrosis are recognized soils for primary liver cancer, particularly hepatocellular carcinoma (HCC), being the third most common cause for cancer-related deaths worldwide. Despite recent advances in liver disease understanding, therapeutic options on pre-malignant and malignant stages remain limited. Thus, there is an urgent need to identify targetable liver disease-driving mechanisms for the development of novel therapeutics. Monocytes and macrophages comprise a central, yet versatile component of the inflammatory response, fueling chronic liver disease initiation and progression. Recent proteomic and transcriptomic studies performed at singular cell levels revealed a previously overlooked diversity of macrophage subpopulations and functions. Indeed, liver macrophages that encompass liver resident macrophages (also named Kupffer cells) and monocyte-derived macrophages, can acquire a variety of phenotypes depending on microenvironmental cues, and thus exert manifold and sometimes contradictory functions. Those functions range from modulating and exacerbating tissue inflammation to promoting and exaggerating tissue repair mechanisms (i.e., parenchymal regeneration, cancer cell proliferation, angiogenesis, fibrosis). Due to these central functions, liver macrophages represent an attractive target for the treatment of liver diseases. In this review, we discuss the multifaceted and contrary roles of macrophages in chronic liver diseases, with a particular focus on NAFLD/NASH and HCC. Moreover, we discuss potential therapeutic approaches targeting liver macrophages.