Amphiregulin couples IL1RL1+ regulatory T cells and cancer-associated fibroblasts to impede antitumor immunity

Silver niobate/platinum piezoelectric heterojunction enhancing intra-tumoral infiltration of immune cells for transforming "cold tumor" into "hot tumor"

Cancer immunotherapy represents a promising strategy, however, its efficacy is often hindered by high tumor interstitial fluid pressure (TIFP) due to fluid retention, and strong solid stress (SS) caused by the excessive proliferation of cancer-associated fibroblasts (CAFs). These factors limit the infiltration of immune cells into the deeper layers of tumors, thereby reducing the efficacy of immunotherapy. In this study, we designed an innovative AgNbO3/Pt@HA (ANPH) Schottky heterojunction system to induce ultrasound (US)-triggered piezocatalytic reactions for cancer therapy, which catalyze the water decomposition in the tumor interstitial fluid to produce H2, therefore, resulting in a 48.16 % reduction in TIFP. Furthermore, the reactive oxygen species (ROS) generated by the system eliminated 59.4 % of CAFs, reducing the tumor extracellular matrix and SS by 44.07 %. This reduction facilitated a 3.95-fold and 3-fold increase in quantities of intratumoral CD8+ and CD4+ T cells, respectively, and transformed "cold tumors" into "hot tumors" to activate systemic immune responses. The growth of primary, distal, and metastatic tumors was significantly inhibited. This study demonstrates effective reductions in intratumoral TIFP and SS, promoting immune cell infiltration and thereby enhancing the efficacy of immunotherapy through US-triggered piezocatalytic reactions, which establishes a new paradigm of the application of nanocatalytic medicine.

Cancer-associated fibroblasts derived amphiregulin promotes HNSCC progression and drug resistance of EGFR inhibitor

In clinical oncology, lack of sustained treatment response is very common in cancer patients and largely limits the efficiency of most anticancer targeted-therapies. While anti-EGFR therapeutics have been extensively employed in head and neck squamous cell carcinoma (HNSCC) management, their clinical efficacy remains limited due to unresolved resistance mechanisms. Notably, the functional role of EGFR ligand proteins in both tumor progression and therapeutic response has not been fully elucidated. Here we reveal that amphiregulin (AREG) as a potential driver of drug resistance of EGFR-targeted treatment in HNSCC patients. We identify a PDGFRβ+FAP+αSMA+ myofibroblast (myCAF) subset as the major source of AREG in tumor microenvironment. TCGA database and clinical cohort demonstrated that patients with high AREG expression exhibited significantly higher lymph node metastasis rates (59.35 %) and poorer prognosis (median 5-year survival: 2.2 years). In contrast, patients with low AREG expression showed reduced metastatic potential (metastasis rate: 45.16 %) and more favorable clinical outcomes (median 5-year survival: 4.8 years). Mechanistically, AREG promotes vascular mimicry formation via epithelial-endothelial transition of tumor cells to offer extra blood supply and metastasis channels. Further, live-cell imaging revealed that AREG induces plasma membrane stabilization of over 90 % receptor proteins while concurrently enhancing receptor recycling, driving EGFR inhibitor resistance. Collectively, our study reveals the crucial role of AREG in tumor landscape, informing a new predictive biomarker of EGFR inhibitor efficiency as well as a new potential therapeutic target of HNSCC.

Crosstalk between T cells and fibroblasts in biomaterial-mediated fibrosis

Biomaterial implants are a critical aspect of our medical therapies and biomedical research and come in various forms: stents, implantable glucose sensors, orthopedic implants, silicone implants, drug delivery systems, and tissue engineered scaffolds. Their implantation triggers a series of biological responses that often times lead to the foreign body response and subsequent fibrotic encapsulation, a dense ECM-rich capsule that isolates the biomaterial and renders it ineffective. These responses lead to the failure of biomaterials and is a major hurdle to overcome and in promoting their success. Much attention has been given to macrophage populations for the inflammatory component of these responses to biomaterials but recent work has identified an important role of T cells and their ability to modulate fibroblast activity and vice versa. In this review, we focus on T cell-fibroblast crosstalk by exploring T cell subsets, critical signaling pathways, and fibroblast populations that have been shown to dictate biomaterial-mediated fibrosis. We then highlight emerging technologies and model systems that enable new insights and avenues to T cell-fibroblast crosstalk that will improve biomaterial outcomes.

Maintenance of graft tissue-resident Foxp3+ cells is necessary for lung transplant tolerance in mice

Mechanisms that mediate allograft tolerance differ between organs. We have previously shown that Foxp3+ T cell-enriched bronchus-associated lymphoid tissue (BALT) is induced in tolerant murine lung allografts and that these Foxp3+ cells suppress alloimmune responses locally and systemically. Here, we demonstrated that Foxp3+ cells that reside in tolerant lung allografts differed phenotypically and transcriptionally from those in the periphery and were clonally expanded. Using a mouse lung retransplant model, we showed that recipient Foxp3+ cells were continuously recruited to the BALT within tolerant allografts. We identified distinguishing features of graft-resident and newly recruited Foxp3+ cells and showed that graft-infiltrating Foxp3+ cells acquired transcriptional profiles resembling those of graft-resident Foxp3+ cells over time. Allografts underwent combined antibody-mediated rejection and acute cellular rejection when recruitment of recipient Foxp3+ cells was prevented. Finally, we showed that local administration of IL-33 could expand and activate allograft-resident Foxp3+ cells, providing a platform for the design of tolerogenic therapies for lung transplant recipients. Our findings establish graft-resident Foxp3+ cells as critical orchestrators of lung transplant tolerance and highlight the need to develop lung-specific immunosuppression.

INHBA+ macrophages and Pro-inflammatory CAFs are associated with distinctive immunosuppressive tumor microenvironment in submucous Fibrosis-Derived oral squamous cell carcinoma

Transcriptomic and metabolic profiles of tumor cells and stromal cells in oral squamous cell carcinoma (OSCC)-derived from oral submucosal fibrosis (OSF) (ODSCC) have been reported. However, the complex intercellular regulatory network within the tumor immunosuppressive microenvironment (TISME) in ODSCC remains poorly elucidated. Here, we utilized single-cell RNA sequencing (scRNA-seq) and spatial transcriptomics (ST) data from GEO database and multiple immunofluorescence staining (mIF) to reveal distinctive TISME of ODSCC. Results found that compared to OSCC without OSF history (NODSCC), OSCC derived from OSF (ODSCC) showed a significant increase in exhausted CD8+T and Treg cells (Ro/e > 1, p < 0.05) and a decrease in cytotoxic T (CTL) (Ro/e < 1). ODSCC enriched in more Inhibin subunit beta A+ Macrophages (INHBA+Mac) and Proinflammatory Cancer-associated Fibroblast (iCAF) versus NODSCC. INHBA+Mac possessed strongest immune-suppressive functions, evidenced by highest immune checkpoint scores, lowest MHC scores and highest expression of SPP1 among macrophages. Moreover, INHBA+Mac in ODSCC presented stronger immune-suppressive functions than that in NODSCC. iCAF differentially highly expressed INHBA and enriched in immune-related pathways and collagen/ECM pathways across CAF subsets, and possessed stronger immune-suppressive functions, as shown by up-regulated gene expression of TDO2, IDO1 and DUSP4 in ODSCC versus in NODSCC. Furthermore, INHBA expression was higher in ODSCC than in NODSCC (p < 0.01). The classic OSF-inducing molecule arecoline significantly increases the expression of INHBA (p < 0.0001) in vitro experiments stimulating THP-1 cells. ST analysis revealed a close co-location of INHBA+Mac, iCAF and Treg and SpaGene identified INHBA-ACVR1/ACVR2A/ACVR2B interaction regions overlapping with distribution of three types of cells. Collectively, ODSCC shows a more severe TISME and potentially poorer sensitivity to immunotherapy than NODSCC. The increased INHBA+Mac and iCAF in ODSCC are associated with the observed more severe TISME. The upregulated INHBA in ODSCC and its interaction with INHBA-ACVR1/ACVR2A/ACVR2B may mediate the modulation effect of INHBA+ Mac and iCAF on Treg differentiation and functionality.

LPS-induced extracellular AREG triggers macrophage pyroptosis through the EGFR/TLR4 signaling pathway

Amphiregulin (AREG), a member of the EGF family, exists as a transmembrane protein anchored to the cell surface. In response to external stimuli, its extracellular domain is released into the extracellular matrix through paracrine or autocrine signaling. However, its role in septic macrophage pyroptosis remains poorly understood. This study aims to investigate the role of extracellular AREG in septic macrophages, mice, and patients. We found that high expression of extracellular AREG was regulated by RPLP1 at the translation level, which increased the expression of IL-6, CCL2, and CCL3 protein, as well as Caspase 1, IL-1β, and Nlrp3 mRNA expression, resulting in macrophage pyroptosis. Mechanistically, macrophage pyroptosis was aggravated by extracellular AREG pretreatment, which was triggered by extracellular AREG and ATP (adenosine 5'-triphosphate). The AREG-neutralizing antibody reduced LPS-induced epidermal growth factor receptor (EGFR) activation, TLR4 expression, and pyroptosis. Extracellular AREG-induced macrophage pyroptosis decreased with EGFR and NF-κB inhibition, as well as TLR4 and Myd88 knockout. Additionally, DTT-pretreated extracellular AREG suppressed macrophage pyroptosis. In vivo, extracellular AREG attenuates systemic inflammation infiltration and delays survival in a septic mouse model. Furthermore, extracellular AREG mediates sepsis in humans, and genes involved in the AREG-mediated pyroptosis signaling pathway were highly expressed in patients with severe sepsis compared with those with general or moderate sepsis. Overall, LPS-induced extracellular AREG aggravated or triggered macrophage pyroptosis through the EGFR/TLR4/Myd88/NF-κB signaling pathway, providing promising treatment strategies for sepsis.

Single-cell RNA sequencing revealed changes in the tumor microenvironment induced by radiotherapy for cervical cancer and the molecular mechanism of mast cells in immunosuppression

Radiotherapy (RT) is an important treatment for cervical cancer (CC), effectively controlling tumor growth and improving survival rates. However, radiotherapy-induced cell heterogeneity and its underlying mechanisms remain unclear, which may potentially impact treatment efficacy. This study aims to investigate tumor microenvironment changes following radiotherapy for CC, hoping to provide evidence to improve the therapeutic effects of radiotherapy. For the first time, we applied single-cell RNA sequencing (scRNA-seq) to analyze tissue samples from three CC patients pre- and post-radiotherapy. We obtained gene expression data from 52,506 cells to identify the cellular changes and molecular mechanisms induced by radiotherapy. Radiotherapy significantly alters cellular composition and gene expression within the tumor microenvironment (TME), notably upregulating mast cell expression. Mast cells are involved in multiple cell axes in the CC ecosystem after radiotherapy, and play a pivotal role in tumor immunosuppression and matrix remodeling. scRNA-seq revealed gene expression variations among cell types after radiotherapy, underscoring the importance of specific cell types in modulating the TME post-treatment. This study revealed the molecular mechanism of radiotherapy for CC and the role of mast cells, providing a foundation for optimizing the personalized treatment of CC.

The dual role of tissue regulatory T cells in tissue repair: return to homeostasis or fibrosis

Tissue resident regulatory T cells (tissue Tregs) are vital for maintaining immune homeostasis and controlling inflammation. They aid in repairing damaged tissues and influencing the progression of fibrosis. However, despite extensive research on how tissue Tregs interact with immune and non-immune cells during tissue repair, their pro- and anti-fibrotic effects in chronic tissue injury remain unclear. Understanding how tissue Tregs interact with various cell types, as well as their roles in chronic injury and fibrosis, is crucial for uncovering the mechanisms behind these conditions. In this review, we describe the roles of tissue Tregs in repair and fibrosis across different tissues and explore potential strategies for regulating tissue homeostasis. These insights hold promise for providing new perspectives and approaches for the treatment of irreversible fibrotic diseases.

Identification and validation of a novel signature based on immune‑related genes from epithelial cells to predict prognosis and treatment response in patients with lung squamous cell cancer by integrated analysis of single‑cell and bulk RNA sequencing

Epithelial cells are associated with tumor immunity through interstitial transformation, yet the role of epithelial immune-related genes (EIGs) in this process remains unclear. Comprehending the mechanisms behind EIGs within lung squamous cell carcinoma (LUSC) may offer an explanation to these issues. The present study aimed to explore the biological role of EIGs in patients with LUSC. Based on data from the Gene Expression Omnibus and The Cancer Genome Atlas databases, a survival model and nomogram was established. This model and nomogram were used to study the mechanism of EIGs in LUSC and its medical significance by enrichment analysis, tumor microenvironment, immune cell infiltration and immune function correlation analysis. Finally, reverse transcription-quantitative PCR (RT-qPCR) and external dataset were used to assess the expression of the EIGs. The survival model was used to develop 4 EIGs as predictors for patient outcomes. Survival curves revealed that higher risk patients had more negative outcomes. This model and the nomogram developed based entirely on this model had an accurate prognosis predictive LUSC. The enrichment analysis indicated that pathways related to antigen processing and presentation, as well as Epstein-Barr virus infection, were prevalent in the high-risk populations. The research on immune infiltration demonstrated a notable rise in activated dendritic cells and neutrophils in the high-risk group. Furthermore, the results revealed that the high-risk populations are particularly susceptible to the effects of afureserpine, gefitinib and savolitinib. Finally, the outcomes of RT-qPCR were consistent with those of the bioinformatics analysis. In conclusion, the risk evaluation model and nomogram are effective in forecasting the prognosis and guiding drug selection for patients with LUSC. A worse prognosis in patients with high risk may be associated with certain viral infections and antigen processing and presentation.

LYVE1 and IL1RL1 are mitochondrial permeability transition-driven necrosis-related genes in heart failure

BACKGROUND

Heart failure is linked to increased hospitalization and mortality. Mitochondrial permeability transition-driven necrosis is associated with cardiovascular diseases, but its role in heart failure is unclear. This study aimed to identify and validate genes related to mitochondrial permeability transition-driven necrosis in heart failure, potentially leading to new drug targets and signaling pathways.

METHODS

We identified differentially expressed genes related to heart failure from the gene expression omnibus database and identified module genes related to mitochondrial permeability transition-driven necrosis from the gene set enrichment analysis database. Key genes were determined by intersecting these two gene groups using least absolute shrinkage and selection operator and support vector machine algorithms. Pathways, diagnostic efficacy, gene interactions, immune infiltration, and regulatory networks were analyzed. Small interfering RNAs were used for validation. Real-time-quantitative polymerase chain reaction, flow cytometry, and JC1 assays were performed in vitro.

RESULTS

Forty-six differentially expressed genes, and 3439 module genes were identified. LYVE1, IL1RL1, and SERPINA3 were identified as significantly downregulated key genes, with IL1RL1 and SERPINA3 associated with heart failure risk. Benzo(a) pyrene, bisphenol A, estradiol, and particulate matter were found to simultaneously increase the expression of three key genes. In clinical samples, only LYVE1 and IL1RL1 were downregulated, as expected. Knockdown of these genes in cells led to increased necrosis and decreased mitochondrial membrane potential. Only estradiol reduced brain natriuretic peptide protein levels in hypertrophic cells.

CONCLUSIONS

LYVE1 and IL1RL1 were validated as key genes linked to mitochondrial permeability transition-driven necrosis in heart failure. Estradiol may have a therapeutic effect on heart failure.

MicroRNA profiling identifies VHL/HIF-2α dependent miR-2355-5p as a key modulator of clear cell Renal cell carcinoma tumor growth

Inactivation of the von Hippel-Lindau (VHL) tumor suppressor gene is one of the first truncal events in clear cell Renal Cell Carcinoma (ccRCC) tumorigenesis. The accumulation of Hypoxia Induced Factor (HIFα) resulting from VHL loss can promote ccRCC tumorigenesis by regulating microRNA (miRNA) expression. Here, we performed miRNA profiling and high-throughput analysis to identify a panel of VHL-dependent miRNAs in ccRCC. Validation of these miRNAs revealed the overexpression of miR-2355-5p in ccRCC cell models and primary tumors. Moreover, we showed a significant increase in circulating miR-2355-5p in plasma from patients with ccRCC. Mechanistically, miR-2355-5p overexpression was confirmed to be HIF-2α dependent. Targeting miR-2355-5p with the CRISPR/Cas9 system not only negatively disrupted the ability of ccRCC cells to stimulate angiogenesis but also decreased cell proliferation and drastically reduced tumor growth in mouse xenograft models. Finally, a miR-2355-5p pulldown assay identified five tumor suppressor genes, ACO1, BTG2, CMTM4, SLIT2, and WDFY2, as potential targets. All five genes were significantly downregulated in ccRCC tumors and mouse xenograft tumors. The results from this research demonstrate the oncogenic ability of miR-2355-5p and shed light on the possible mechanism by which this miRNA controls angiogenesis and tumor growth in VHL-deficient ccRCC.

Eniluracil blocks AREG signalling-induced pro-inflammatory fibroblasts of melanoma in heart failure

AIMS

Heart failure (HF) is characterized by a heightened risk of melanoma, which often metastasizes to the heart. The overlap pathology between HF and melanoma includes chronic low-grade inflammation and dysregulation of inflammatory cancer-associated fibroblasts (iCAFs). The impact of HF on iCAF-driven tumour inflammation remains obscure.

METHODS AND RESULTS

To identify critical genes for HF development, transcriptomic data (GSE57338) containing 313 clinical HF samples [136 healthy controls, 95 ischaemia (ISCH) and 82 dilated cardiomyopathy (DCM)] were analysed to screen differentially expressed genes (DEGs) and perform enrichment analysis. Fifty-one DEGs in ISCH and 62 DEGs in DCM were identified with log2|fold change (FC)| ≥ 1 and P value ≤0.05. All these genes are involved in extracellular matrix organization, immune/inflammatory responses and Wnt signalling pathways. Then, the overall survival curves and prognostic models of DEGs in melanoma were evaluated. The correlation of gene expression with lymphocyte infiltration levels was assessed. Only aldehyde oxidase 1 (AOX1) and amphiregulin (AREG) maintained the same trend in melanoma as in HF, negatively affecting prognosis by regulating lymphocyte infiltration (log-rank P value = 0.0017 and 0.0019). The potential drug molecules were screened, and the binding energies were calculated via molecular docking. Eniluracil, a known AOX1 targeting drug, was found to stably bind with AREG (hydrogen bond binding energies: -65.633, -63.592 and -62.813 kcal/mol).

CONCLUSIONS

The increased prevalence of melanoma in HF patients and its propensity for cardiac metastasis may be due to AREG-mediated systemic low-grade inflammation. Eniluracil holds promise as a therapeutic agent that may block AREG signalling, inhibiting the activation of iCAF mediated by regulatory T cell (Treg) and neutrophil.

Tregs ST2 deficiency enhances the abscopal anti-tumor response induced by microwave ablation

BACKGROUND

Thermal ablation (TA), including radiofrequency ablation (RFA) and Microwave ablation (MWA) could reduce tumor burden and can stimulate an immune response, but it cannot maintain a lasting immune response. The alarming cytokine IL-33 is constitutively expressed by epithelial cells, endothelial cells, and fibroblasts, but is released during tissue injury to alert the immune system. The presence of ST2+Tregs in TME may act as a barrier contributing to this phenomenon.

METHODS

In this study, we explored the impact of RFA on the expression of ST2 (also known as IL1RL1) in tumor-infiltrating lymphocytes (TILs). Subsequently, we constructed a Treg cell-specific deletion ST2 mouse model (Foxp3CreIl1rl1fl/fl) and evaluated the genetic phenotypes by flow cytometry. A bilateral dorsal tumor-bearing model was established in Foxp3Cre and Foxp3CreIl1rl1fl/fl mice to explore the anti-tumor effect of MWA. Finally, we used flow cytometry and single-cell transcriptome sequencing (scRNA-seq) to profile CD45+ immune cells within TME.

RESULTS

Our findings suggest that ablation upregulates ST2 expression in Tregs within the contralateral TME. Compared with Foxp3Cre mice, MWA significantly inhibited the growth of contralateral tumors in Foxp3CreIl1rl1fl/fl mice. Its mechanisms include reducing the proportion of Tregs, enhancing the infiltration and effector function of CD8+T cells, increasing the proportion of Effector CD8+T cells, reducing the proportion of Exhausted CD8+T cells, increasing MHC-I molecules in mDC cells and monocytes, and reducing the expression of TAM2 inhibitory molecules and chemokines.

CONCLUSIONS

Blocking IL-33/ST2 pathway in Tregs offers a new strategy for MWA in clinical studies of metastatic cancer.

Vimentin modulates regulatory T cell receptor-ligand interactions at distal pole complex, leading to dysregulated host response to viral pneumonia

Forkhead box P3 (Foxp3)+ regulatory T cells (Tregs) resolve acute inflammation and repair the injured lung after viral pneumonia. Vimentin is a critical protein in the distal pole complex (DPC) of Tregs. This study reveals the inhibitory effect of vimentin on the suppressive and reparative capacity of Tregs. Treg-specific deletion of vimentin increases Helios+interleukin-18 receptor (IL-18R)+ Tregs, suppresses inflammatory immune cells, and enhances tissue repair, protecting Vimfl/flFoxp3YFP-cre mice from influenza-induced lung injury and mortality. Mechanistically, vimentin suppresses the induction of amphiregulin, an epidermal growth factor receptor (EGFR) ligand necessary for tissue repair, by sequestering IL-18R to the DPC and restricting receptor-ligand interactions. We propose that vimentin in the DPC of Tregs functions as a molecular switch, which could be targeted to regulate the immune response and enhance tissue repair in patients with severe viral pneumonia.

Single-cell resolution spatial analysis of antigen-presenting cancer-associated fibroblast niches

Recent studies have identified a unique subtype of cancer-associated fibroblasts (CAFs) termed antigen-presenting CAFs (apCAFs), which remain the least understood CAF subtype. To gain a comprehensive understanding of the origin and function apCAFs, we construct a fibroblast molecular atlas across 14 types of solid tumors. Our integration study unexpectedly reveals two distinct apCAF lineages present in most cancer types: one associated with mesothelial-like cells and the other with fibrocytes. Using a high-resolution single-cell spatial imaging platform, we characterize the spatial niches of these apCAF lineages. We find that mesothelial-like apCAFs are located near cancer cells, while fibrocyte-like apCAFs are associated with tertiary lymphoid structures. Additionally, we discover that both apCAF lineages can up-regulate the secreted protein SPP1, which facilitates primary tumor formation and peritoneal metastasis. Taken together, this study offers an unprecedented resolution in analyzing apCAF lineages and their spatial niches.

Self-Oxygenated Hydrogel Enhances Immune Cell Response and Infiltration Via Triggering Dual DNA Damage to Activate cGAS-STING and Inhibiting CAFs

Immune checkpoint inhibitors (ICIs) offer promise in breaking through the treatment and survival dilemma of triple-negative breast cancer (TNBC), yet only immunomodulatory subtype and ≈5% TNBC patients respond as monotherapy due to lack of effector immune cells (internal problem) and physical barrier (external limitation) formed by cancer-associated fibroblasts (CAFs). A hydrogel drug-delivery platform, ALG@TBP-2/Pt(0)/nintedanib (ALG@TPN), is designed to induce strong immune functions and the dual elimination of the internal and external tumor microenvironment (TME). Activated by white light, through type I and II photodynamic therapy (PDT), TBP-2 generates large amounts of reactive oxygen species (ROS) intracellularly, oxidizing mitochondrial DNA (mtDNA). The unique catalase activity of Pt(0) converts endogenous H2O2 to O2, reducing the anoxia-limiting PDT and enhancing ROS generation efficacy. Abundant ROS can oxidize Pt(0) to cytotoxic Pt(II), damaging the nuclear DNA (nDNA). Dual damage to mtDNA and nDNA might bi-directionally activate the cGAS/STING pathway and enhance the immune cell response. Besides, nintedanib demonstrates a significant inhibitory effect on CAFs, weakening the immune barrier and deepening immune cell infiltration. Overall, the study provides a self-oxygenating hydrogel with the "PDT/chemotherapy/anti-CAFs" effect, triggering the cGAS/STING pathway to reshape the TME. Both internal and external interventions increase anti-TNBC immune responses.

Decoding tumor-fibrosis interplay: mechanisms, impact on progression, and innovative therapeutic strategies

Malignant tumors are a category of diseases that possess invasive and metastatic capabilities, with global incidence and mortality rates remaining high. In recent years, the pivotal role of fibrosis in tumor progression, drug resistance, and immune evasion has increasingly been acknowledged. Fibrosis enhances the proliferation, migration, and invasion of tumor cells by modifying the composition and structure of the extracellular matrix, thereby offering protection for immune evasion by tumor cells. The activation of cancer-associated fibroblasts (CAFs) plays a significant role in this process, as they further exacerbate the malignant traits of tumors by secreting a variety of cytokines and growth factors. Anti-fibrotic tumor treatment strategies, including the use of anti-fibrotic drugs and inhibition of fibrosis-related signaling pathways such as Transforming Growth Factor-β (TGF-β), have demonstrated potential in delaying tumor progression and improving the effectiveness of chemotherapy, targeted therapy, and immunotherapy. In the future, by developing novel drugs that target the fibrotic microenvironment, new therapeutic options may be available for patients with various refractory tumors.

Assessment of combined serum sST2 and AFP levels in the diagnosis of hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is a common malignant tumor with high morbidity and mortality. Alpha-fetoprotein (AFP) is the most widely used diagnostic serum biomarker, but it still has limited accuracy in detecting HCC, suggesting the necessity of seeking more ideal biomarkers with high sensitivity and specificity. Soluble growth stimulation gene 2 (sST2) form of growth stimulating expression gene 2 (ST2), is expressed in various organs and can bind competitively to interleukin 33 (IL-33). Whether sST2 can serve as a serum biomarker for HCC is largely unknown.

Objective

To investigate the value of sST2 as a serum diagnostic marker for HCC.

Methods

This study included 93 newly diagnosed HCC patients (HCC group), 90 chronic hepatitis B patients (CHB group), and 90 healthy individuals (HCs group). Spearman correlation analysis was used to explore the relationships between sST2 and the experimental indicators in HCC group. The receiver operating characteristic (ROC) curve evaluated the efficacy of sST2 alone or in combination with AFP in the diagnosis of HCC.

Result

The median level of sST2 was significantly higher in HCC group (24.00 [15.20-49.90] ng/mL) compared to CHB group (19.55 [15.23-24.95] ng/mL) and HCs group (7.65 [5.20-10.53] ng/mL). No significant correlations were found between sST2 and other clinical indicators in HCC group. The Area Under Curve (AUC) of ROC curve to distinguish HCC patients from healthy controls and CHB group was 0.861 (sensitivity 82.80%, specificity 72.10%) and 0.709 (sensitivity 80.60%, specificity 52.50%), respectively. When combined with AFP, the AUC increased to 0.963 (sensitivity 82.90%, specificity 94.20%), and 0.895 (sensitivity 72.0%, specificity 100%), respectively.

Conclusions

The serum level of sST2 increased in HCC and its diagnostic performance is comparable to that of AFP, supporting its potential as a promising biomarker for detection of HCC. The combined use of sST2 and AFP enhances diagnostic efficacy for HCC.

Expression, DNA methylation pattern and transcription factor EPB41L3 in gastric cancer: a study of 262 cases

PURPOSE

DNA methylation prominently inactivates tumor suppressor genes and facilitates oncogenesis. Previously, we delineated a chromosome 18 deletion encompassing the erythrocyte membrane protein band 4.1-like 3 (EPB41L3) gene, a progenitor for the tumor suppressor that is differentially expressed in adenocarcinoma of the lung-1 (DAL-1) in gastric cancer (GC).

METHODS

Our current investigation aimed to elucidate EPB41L3 expression and methylation in GC, identify regulatory transcription factors, and identify affected downstream pathways. Immunohistochemistry demonstrated that DAL-1 expression is markedly reduced in GC tissues, with its downregulation serving as an independent prognostic marker.

RESULTS

High-throughput bisulfite sequencing of 70 GC patient tissue pairs revealed that higher methylation of non-CpGs in the EPB41L3 promoter was correlated with more malignant tumor progression and higher-grade tissue classification. Such hypermethylation was shown to diminish DAL-1 expression, thus contributing to the malignancy of GC phenotypes. The DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine (5-aza-CdR) was found to partially restore DAL-1 expression. Moreover, direct binding of the transcription factor CDC5L to the upstream region of the EPB41L3 promoter was identified via chromosome immunoprecipitation (ChIP)-qPCR and luciferase reporter assays. Immunohistochemistry confirmed the positive correlation between CDC5L and DAL-1 protein levels. Subsequent RNA-seq analysis revealed that DAL-1 significantly influences the extracellular matrix and space-related pathways. GC cell RNA-seq post-5-Aza-CdR treatment and single-cell RNA-seq data of GC tissues confirmed the upregulation of AREG and COL17A1, pivotal tumor suppressors, in response to EPB41L3 demethylation or overexpression in GC epithelial cells.

CONCLUSION

In conclusion, this study elucidates the association between non-CpG methylation of EPB41L3 and GC progression and identifies the key transcription factors and downstream molecules involved. These findings enhance our understanding of the role of EPB41L3 in gastric cancer and provide a solid theoretical foundation for future research and potential clinical applications.

Targeting IL-33 reprograms the tumor microenvironment and potentiates antitumor response to anti-PD-L1 immunotherapy

BACKGROUND

The main challenge against patients with cancer to derive benefits from immune checkpoint inhibitors targeting PD-1/PD-L1 appears to be the immunosuppressive tumor microenvironment (TME), in which IL-33/ST2 signal fulfills critical functions. However, whether IL-33 limits the therapeutic efficacy of anti-PD-L1 remains uncertain.

METHODS

Molecular mechanisms of IL-33/ST2 signal on anti-PD-L1 treatment lewis lung carcinoma tumor model were assessed by RNA-seq, ELISA, WB and immunofluorescence (IF). A sST2-Fc fusion protein was constructed for targeting IL-33 and combined with anti-PD-L1 antibody for immunotherapy in colon and lung tumor models. On this basis, bifunctional fusion proteins were generated for PD-L1-targeted blocking of IL-33 in tumors. The underlying mechanisms of dual targeting of IL-33 and PD-L1 revealed by RNA-seq, scRNA-seq, FACS, IF and WB.

RESULTS

After anti-PD-L1 administration, tumor-infiltrating ST2+ regulatory T cells (Tregs) were elevated. Blocking IL-33/ST2 signal with sST2-Fc fusion protein potentiated antitumor efficacy of PD-L1 antibody by enhancing T cell responses in tumor models. Bifunctional fusion protein anti-PD-L1-sST2 exhibited enhanced antitumor efficacy compared with combination therapy, not only inhibited tumor progression and extended the survival, but also provided long-term protective antitumor immunity. Mechanistically, the superior antitumor activity of targeting IL-33 and PD-L1 originated from reducing immunosuppressive factors, such as Tregs and exhausted CD8+ T cells while increasing tumor-infiltrating cytotoxic T lymphocyte cells.

CONCLUSIONS

In this study, we demonstrated that IL-33/ST2 was involved in the immunosuppression mechanism of PD-L1 antibody therapy, and blockade by sST2-Fc or anti-PD-L1-sST2 could remodel the inflammatory TME and induce potent antitumor effect, highlighting the potential therapeutic strategies for the tumor treatment by simultaneously targeting IL-33 and PD-L1.

The immunomodulatory of interleukin-33 in rheumatoid arthritis: A systematic review

Rheumatoid arthritis (RA) is a systemic chronic autoimmune disease that primarily affects the joints and surrounding soft tissues, characterized by chronic inflammation and proliferation of the synovium. Various immune cells are involved in the pathophysiology of RA. The complex interplay of factors such as chronic inflammation, genetic susceptibility, dysregulation of serum antibody levels, among others, contribute to the complexity of the disease mechanism, disease activity, and treatment of RA. Recently, the cytokine storm leading to increased disease activity in RA has gained significant attention. Interleukin-33 (IL-33), a member of the IL-1 family, plays a crucial role in inflammation and immune regulation. ST2 (suppression of tumorigenicity 2 receptor), the receptor for IL-33, is widely expressed on the surface of various immune cells. When IL-33 binds to its receptor ST2, it activates downstream signaling pathways to exert immunoregulatory effects. In RA, IL-33 regulates the progression of the disease by modulating immune cells such as circulating monocytes, tissue-resident macrophages, synovial fibroblasts, mast cells, dendritic cells, neutrophils, T cells, B cells, endothelial cells, and others. We have summarized and analyzed these findings to elucidate the pathways through which IL-33 regulates RA. Furthermore, IL-33 has been detected in the synovium, serum, and synovial fluid of RA patients. Due to inconsistent research results, we conducted a meta-analysis on the association between serum IL-33, synovial fluid IL-33, and the risk of developing RA in patients. The pooled SMD was 1.29 (95% CI: 1.15-1.44), indicating that IL-33 promotes the onset and pathophysiological progression of RA. Therefore, IL-33 may serve as a biomarker for predicting the risk of developing RA and treatment outcomes. As existing drugs for RA still cannot address drug resistance in some patients, new therapeutic approaches are needed to alleviate the significant burden on RA patients and healthcare systems. In light of this, we analyzed the potential of targeting the IL-33/ST2-related signaling pathway to modulate immune cells associated with RA and alleviate inflammation. We also reviewed IL-33 and RA susceptibility-related single nucleotide polymorphisms, suggesting potential involvement of IL-33 and macrophage-related drug-resistant genes in RA resistance therapy. Our review elucidates the role of IL-33 in the pathophysiology of RA, offering new insights for the treatment of RA.

Single-cell RNA sequencing in ovarian cancer: revealing new perspectives in the tumor microenvironment

Single-cell sequencing technology has emerged as a pivotal tool for unraveling the complexities of the ovarian tumor microenvironment (TME), which is characterized by its cellular heterogeneity and intricate cell-to-cell interactions. Ovarian cancer (OC), known for its high lethality among gynecologic malignancies, presents significant challenges in treatment and diagnosis, partly due to the complexity of its TME. The application of single-cell sequencing in ovarian cancer research has enabled the detailed characterization of gene expression profiles at the single-cell level, shedding light on the diverse cell populations within the TME, including cancer cells, stromal cells, and immune cells. This high-resolution mapping has been instrumental in understanding the roles of these cells in tumor progression, invasion, metastasis, and drug resistance. By providing insight into the signaling pathways and cell-to-cell communication mechanisms, single-cell sequencing facilitates the identification of novel therapeutic targets and the development of personalized medicine approaches. This review summarizes the advancement and application of single-cell sequencing in studying the stromal components and the broader TME in OC, highlighting its implications for improving diagnosis, treatment strategies, and understanding of the disease's underlying biology.

Enhanced amphiregulin exposure promotes modulation of the high grade serous ovarian cancer tumor immune microenvironment

High grade serous ovarian cancer (HGSOC) is a lethal gynecologic malignancy in which chemoresistant recurrence rates remain high. Furthermore, HGSOC patients have demonstrated overall low response rates to clinically available immunotherapies. Amphiregulin (AREG), a low affinity epidermal growth factor receptor ligand is known to be significantly upregulated in HGSOC patient tumors following neoadjuvant chemotherapy exposure. While much is known about AREG's role in oncogenesis and classical immunity, it is function in tumor immunology has been comparatively understudied. Therefore, the objective of this present study was to elucidate how increased AREG exposure impacts the ovarian tumor immune microenvironment (OTIME). Using NanoString IO 360 and protein analysis, it was revealed that treatment with recombinant AREG led to prominent upregulation of genes associated with ovarian pathogenesis and immune evasion (CXCL8, CXCL1, CXCL2) along with increased STAT3 activation in HGSOC cells. In vitro co-culture assays consisting of HGSOC cells and peripheral blood mononuclear cells (PBMCs) stimulated with recombinant AREG (rAREG) led to significantly enhanced tumor cell viability. Moreover, PBMCs stimulated with rAREG exhibited significantly lower levels of IFNy and IL-2. In vivo rAREG treatment promoted significant reductions in circulating levels of IL-2 and IL-5. Intratumoral analysis of rAREG treated mice revealed a significant reduction in CD8+ T cells coupled with an upregulation of PD-L1. Finally, combinatorial treatment with an AREG neutralizing antibody and carboplatin led to a synergistic reduction of cell viability in HGSOC cell lines OVCAR8 and PEA2. Overall, this study demonstrates AREG's ability to modulate cytotoxic responses within the OTIME and highlights its role as a novel HGSOC immune target.

Single-cell data revealed exhaustion of characteristic NK cell subpopulations and T cell subpopulations in hepatocellular carcinoma

BACKGROUND

The treatment and prognosis of patients with advanced hepatocellular carcinoma (HCC) have been a major medical challenge. Unraveling the landscape of tumor immune infiltrating cells (TIICs) in the immune microenvironment of HCC is of great significance to probe the molecular mechanisms.

METHODS

Based on single-cell data of HCC, the cell landscape was revealed from the perspective of TIICs. Special cell subpopulations were determined by the expression levels of marker genes. Differential expression analysis was conducted. The activity of each subpopulation was determined based on the highly expressed genes. CTLA4+ T-cell subpopulations affecting the prognosis of HCC were determined based on survival analysis. A single-cell regulatory network inference and clustering analysis was also performed to determine the transcription factor regulatory networks in the CTLA4+ T cell subpopulations.

RESULTS

10 cell types were identified and NK cells and T cells showed high abundance in tumor tissues. Two NK cells subpopulations were present, FGFBP2+ NK cells, B3GNT7+ NK cells. Four T cells subpopulations were present, LAG3+ T cells, CTLA4+ T cells, RCAN3+ T cells, and HPGDS+ Th2 cells. FGFBP2+ NK cells, and CTLA4+ T cells were the exhaustive subpopulation. High CTLA4+ T cells contributed to poor prognostic outcomes and promoted tumor progression. Finally, a network of transcription factors regulated by NR3C1, STAT1, and STAT3, which were activated, was present in CTLA4+ T cells.

CONCLUSION

CTLA4+ T cell subsets in HCC exhibited functional exhaustion characteristics that probably inhibited T cell function through a transcription factor network dominated by NR3C1, STAT1, and STAT3.

IL-33 supplementation improves uterine artery resistance and maternal hypertension in response to placental ischemia

Preeclampsia (PE), a leading cause of maternal/fetal morbidity and mortality, is a hypertensive pregnancy disorder with end-organ damage that manifests after 20 wk of gestation. PE is characterized by chronic immune activation and endothelial dysfunction. Clinical studies report reduced IL-33 signaling in PE. We use the Reduced Uterine Perfusion Pressure (RUPP) rat model, which mimics many PE characteristics including reduced IL-33, to identify mechanisms mediating PE pathophysiology. We hypothesized that IL-33 supplementation would improve blood pressure (BP), inflammation, and oxidative stress (ROS) during placental ischemia. We implanted intraperitoneal mini-osmotic pumps infusing recombinant rat IL-33 (1 µg/kg/day) into normal pregnant (NP) and RUPP rats from gestation day 14 to 19. We found that IL-33 supplementation in RUPP rats reduces maternal blood pressure and improves the uterine artery resistance index (UARI). In addition to physiological improvements, we found decreased circulating and placental cytolytic Natural Killer cells (cNKs) and decreased circulating, placental, and renal TH17s in IL-33-treated RUPP rats. cNK cell cytotoxic activity also decreased in IL-33-supplemented RUPP rats. Furthermore, renal ROS and placental preproendothelin-1 (PPET-1) decreased in RUPP rats treated with IL-33. These findings demonstrate a role for IL-33 in controlling vascular function and maternal BP during pregnancy by decreasing inflammation, renal ROS, and PPET-1 expression. These data suggest that IL-33 may have therapeutic potential in managing PE.NEW & NOTEWORTHY Though decreased IL-33 signaling has been clinically associated with PE, the mechanisms linking this signaling pathway to overall disease pathophysiology are not well understood. This study provides compelling evidence that mechanistically links reduced IL-33 with the inflammatory response and vascular dysfunction observed in response to placental ischemia, such as in PE. Data presented in this study submit the IL-33 signaling pathway as a possible therapeutic target for the treatment of PE.

Selective targeting or reprogramming of intra-tumoral Tregs

Regulatory T cells (Tregs) are critical immunosuppressive cells that are frequently present in the tumor microenvironment of solid cancers and enable progression of tumors toward metastasis. The cells expand in response to tumor-associated antigens and are actively involved in bypassing immunotherapy with immune checkpoint inhibitors through integrating numerous environmental signals. A point here is that Tregs are clonally distinct in peripheral blood from tumor area. Currently, an effective and novel task in cancer immunotherapy is to selectively destabilize or deplete intra-tumoral Tregs in order to avoid systemic inflammatory events. Helios is a transcription factor expressed selectively by Tregs and promotes their stabilization, and Trps1 is a master regulator of intra-tumoral Tregs. Anti-CCR8 and the IL-2Rβγ agonist Bempegaldesleukin selectively target intra-tumoral Treg population, with the former approved to not elicit autoimmunity. Disarming Treg-related immunosuppression in tumors through diverting their reprogramming or promoting naïve T cell differentiation into cells with effector immune activating profile is another promising area of research in cancer immunotherapy. Blimp-1 inhibitors and glucocorticoid-induced TNFR-related protein agonists are example approaches that can be used for diverting Treg differentiation into Th1-like CD4+ T cells, thereby powering immunogenicity against cancer. Finally, selective target of intra-tumoral Tregs and their reprogramming into effector T cells is applicable using low-dose chemotherapy, and high-salt and high-tryptophan diet.

Navigating the Immune Maze: Pioneering Strategies for Unshackling Cancer Immunotherapy Resistance

Cancer immunotherapy has ushered in a transformative era in oncology, offering unprecedented promise and opportunities. Despite its remarkable breakthroughs, the field continues to grapple with the persistent challenge of treatment resistance. This resistance not only undermines the widespread efficacy of these pioneering treatments, but also underscores the pressing need for further research. Our exploration into the intricate realm of cancer immunotherapy resistance reveals various mechanisms at play, from primary and secondary resistance to the significant impact of genetic and epigenetic factors, as well as the crucial role of the tumor microenvironment (TME). Furthermore, we stress the importance of devising innovative strategies to counteract this resistance, such as employing combination therapies, tailoring immune checkpoints, and implementing real-time monitoring. By championing these state-of-the-art methods, we anticipate a paradigm that blends personalized healthcare with improved treatment options and is firmly committed to patient welfare. Through a comprehensive and multifaceted approach, we strive to tackle the challenges of resistance, aspiring to elevate cancer immunotherapy as a beacon of hope for patients around the world.