Expression of Ferroptosis-Related Genes Shapes Tumor Microenvironment and Pharmacological Profile in Gastric Cancer

Mechanism and role of ferroptosis in the development of gastric cancer

Gastric cancer (GC) represents a prevalent form of malignant neoplasm characterized by elevated incidence and fatality rates, limited early detection capabilities, and unfavorable clinical outcomes. Its occurrence and development involve complex biological processes. As a recently identified form of cellular demise, ferroptosis has been observed across multiple cancer types, garnering significant research interest in contemporary studies. Nevertheless, the precise regulatory networks governing ferroptosis in gastric cancer, along with its functional implications in the initiation and advancement of this malignancy, remain unclear. This study seeks to elucidate the functional significance of ferroptosis in the pathogenesis of GC, systematically review the dysregulated metabolic pathways associated with this cell death process, and elucidate the intricate interactions among ferroptosis-related signaling cascades. These investigations are expected to establish a novel conceptual framework for understanding the molecular pathogenesis of gastric cancer and identifying potential therapeutic interventions. A comprehensive literature search was conducted using PubMed to identify relevant original research articles and review papers examining the molecular mechanisms underlying ferroptosis in gastric carcinoma. The search strategy incorporated the following key terms: "Ferroptosis," "Ferroptosis and gastric cancer," "Ferroptosis and GSH," "Ferroptosis and GPX4," "Ferroptosis and system Xc-," "Iron metabolism," "lipid peroxidation," "FSP1-CoQ10," "DHODH-CoQH2," "GCH1-BH4," "ferroptosis inducer," etc. Emerging evidence from contemporary research indicates that targeted ferroptosis represents a novel and potentially efficacious treatment modality for patients with gastric cancer. Along with the identification of precise molecular targets for therapeutic intervention, the metabolic regulatory networks associated with ferroptosis remains an essential area for future research endeavors.

Bidirectional crosstalk between the epithelial-mesenchymal transition and immunotherapy: A bibliometric study

Immunotherapy has recently attracted considerable attention. However, currently, a thorough analysis of the trends associated with the epithelial-mesenchymal transition (EMT) and immunotherapy is lacking. In this study, we used bibliometric tools to provide a comprehensive overview of the progress in EMT-immunotherapy research. A total of 1,302 articles related to EMT and immunotherapy were retrieved from the Web of Science Core Collection (WOSCC). The analysis indicated that in terms of the volume of research, China was the most productive country (49.07%, 639), followed by the United States (16.89%, 220) and Italy (3.6%, 47). The United States was the most influential country according to the frequency of citations and citation burstiness. The results also suggested that Frontiers in Immunotherapy can be considered as the most influential journal with respect to the number of articles and impact factors. "Immune infiltration," "bioinformatics analysis," "traditional Chinese medicine," "gene signature," and "ferroptosis" were found to be emerging keywords in EMT-immunotherapy research. These findings point to potential new directions that can deepen our understanding of the mechanisms underlying the combined effects of immunotherapy and EMT and help develop strategies for improving immunotherapy.

Ferroptosis: opening up potential targets for gastric cancer treatment

The fifth most frequent cancer in the world is gastric cancer. It ranks as the fourth most common reason for cancer-related deaths. Even though surgery is the only curative treatment for stomach cancer, adding adjuvant radiotherapy and chemotherapy is preferable than only surgery. The majority of patients, however, are discovered to be extremely tardy the first time and have a terrible prognosis. Therefore, it is necessary to create more viable therapy modalities. A growing number of studies in recent years have shown that ferroptosis and many cancer types are related. This gives our treatment a fresh viewpoint. We investigated the relationship between different signal pathways and non-coding RNA on ferroptosis in gastric cancer cells. Also discussed the targets cause ferroptosis resistance increased or reduced to the influence of the chemoresistance,proliferation and metastasis.

Tumor microenvironment characteristics of lipid metabolism reprogramming related to ferroptosis and EndMT influencing prognosis in gastric cancer

BACKGROUND

Gastric cancer (GC) is a refractory malignant tumor with high tumor heterogeneity, a low rate of early diagnosis, and poor patient prognosis. Lipid metabolism reprogramming plays a critical role in tumorigenesis and progression, but its prognostic role and regulatory mechanism in GC are rarely studied. Thus, the identification of signatures related to lipid metabolism is necessary and may present a new avenue for improving the overall prognosis of GC.

METHODS

Lipid metabolism-associated genes (LMAGs) with differential expression in tumor and tumor-adjacent tissue were acquired to identify lipid metabolism-associated subtypes. The differentially expressed genes (DEGs) between the two clusters were then utilized for prognostic analysis and signature construction. Additionally, pathway enrichment analysis and immune cell infiltration analysis were employed to identify the characteristics of the prognostic model. Further analyses were conducted at the single-cell level to better understand the model's prognostic mechanism. Finally, the prediction of immunotherapy response was used to suggest potential treatments.

RESULTS

Two lipid metabolism-associated subtypes were identified and 9 prognosis-related genes from the DEGs between the two clusters were collected for the construction of the prognostic model named lipid metabolism-associated signature (LMAS). Then we found the low LMAS patients with favorable prognoses were more sensitive to ferroptosis in the Cancer Genome Atlas of Stomach Adenocarcinoma (TCGA-STAD). Meanwhile, the tumor cells exhibiting high levels of lipid peroxidation and accumulation of reactive oxygen species (ROS) in single-cell levels were primarily enriched in the low LMAS group, which was more likely to induce ferroptosis. In addition, endothelial cells and cancer-associated fibroblasts (CAFs) facilitated tumor angiogenesis, proliferation, invasion, and metastasis through endothelial-mesenchymal transition (EndMT), affecting the prognosis of the patients with high LMAS scores. Moreover, CD1C- CD141- dendritic cells (DCs) also secreted pro-tumorigenic cytokines to regulate the function of endothelial cells and CAFs. Finally, the patients with low LMAS scores might have better efficacy in immunotherapy.

CONCLUSIONS

A LMAS was constructed to guide GC prognosis and therapy. Meanwhile, a novel anti-tumor effect was found in lipid metabolism reprogramming of GC which improved patients' prognosis by regulating the sensitivity of tumor cells to ferroptosis. Moreover, EndMT may have a negative impact on GC prognosis.

Ferroptosis and its role in gastric and colorectal cancers

Ferroptosis is a novel mechanism of programmed cell death, characterized by intracellular iron overload, intensified lipid peroxidation, and abnormal accumulation of reactive oxygen species, which ultimately resulting in cell membrane impairment and demise. Research has revealed that cancer cells exhibit a greater demand for iron compared to normal cells, indicating a potential susceptibility of cancer cells to ferroptosis. Stomach and colorectal cancers are common gastrointestinal malignancies, and their elevated occurrence and mortality rates render them a global health concern. Despite significant advancements in medical treatments, certain unfavorable consequences and drug resistance persist. Consequently, directing attention towards the phenomenon of ferroptosis in gastric and colorectal cancers holds promise for enhancing therapeutic efficacy. This review aims to elucidate the intricate cellular metabolism associated with ferroptosis, encompassing lipid and amino acid metabolism, as well as iron metabolic processes. Furthermore, the significance of ferroptosis in the context of gastric and colorectal cancer is thoroughly examined and discussed.

Myricetin Induces Ferroptosis and Inhibits Gastric Cancer Progression by Targeting NOX4

Ferroptosis holds great potential as a therapeutic approach for gastric cancer (GC), a prevalent and deadly malignant tumor associated with high rates of incidence and mortality. Myricetin, well-known for its multifaceted biomedical attributes, particularly its anticancer properties, has yet to be thoroughly investigated regarding its involvement in ferroptosis. The aim of this research was to elucidate the impact of myricetin on ferroptosis in GC progression. The present study observed that myricetin could trigger ferroptosis in GC cells by enhancing malondialdehyde production and Fe2+ accumulation while suppressing glutathione levels. Mechanistically, myricetin directly interacted with NADPH oxidase 4 (NOX4), influencing its stability by inhibiting its ubiquitin degradation. Moreover, myricetin regulated the inhibition of ferroptosis induced by Helicobacter pylori cytotoxin-associated gene A (CagA) through the NOX4/NRF2/GPX4 pathway. In vivo experiments demonstrated that myricetin treatment significantly inhibited the growth of subcutaneous tumors in BALB/c nude mice. It was accompanied by increased NOX4 expression in tumor tissue and suppression of the NRF2/GPX4 antioxidant pathway. Therefore, this research underscores myricetin as a novel inducer of ferroptosis in GC cells through its interaction with NOX4. It is a promising candidate for GC treatment.

The putative role of ferroptosis in gastric cancer: a review

Ferroptosis is a unique cell death modality triggered by iron-dependent lipid peroxidation, with cysteine metabolism and glutathione-dependent antioxidant defence responses as the primary triggering mechanisms. Ferroptosis is an independent tumour suppression mechanism and has been implicated in various disorders. In tumourigenesis, ferroptosis plays a dual role in promoting and inhibiting tumours. P53, NFE2L2, BAP1, HIF, and other tumour suppressor genes regulate ferroptosis, releasing damage-associated molecular patterns or lipid metabolites to influence cellular immune responses. Ferroptosis is also involved in tumour suppression and metabolism. The combination of amino acid, lipid, and iron metabolism is involved in the initiation and execution of ferroptosis, and metabolic regulatory mechanisms also play roles in malignancies. Most investigations into ferroptosis in gastric cancer are concentrated on predictive models, not the underlying processes. This review investigates the underlying mechanisms of ferroptosis, tumour suppressor genes, and the tumour microenvironment.

Exosomal circBBS2 inhibits ferroptosis by targeting miR-494 to activate SLC7A11 signaling in ischemic stroke

Umbilical cord-mesenchymal stem cells (UC-MSCs)-derived exosomes have been considered as an effective treatment for ischemic stroke. CircRNA BBS2 (circBBS2) was demonstrated to be down-regulated in patients with ischemic stroke. However, the role of UC-MSCs-derived exosomal circBBS2 in ischemic stroke and potential mechanisms remain unclear. Hypoxia/reperfusion (H/R)-exposed SH-SY5Y cells and middle cerebral artery occlusion (MCAO)-treated rats were served as in vitro and in vivo models of ischemic stroke. Target gene expression was detected by qRT-PCR. Cell viability was assessed by MTT assay. Ferroptosis was determined by iron, MDA, GSH, and lipid ROS levels. Protein levels were measured by Western blotting. The target relationships among circBBS2, miR-494, and SLC7A11 were validated by RNA-pull down, RIP, and dual-luciferase reporter assays. TTC and HE staining were performed to evaluate cerebral infarction volume and neuropathological changes. circBBS2 was lowly expressed and ferroptosis was triggered in MCAO rats and H/R-stimulated SH-SY5Y cells. UC-MSCs-derived exosomes enhanced cell viability and restrained ferroptosis via increasing circBBS2 expression in SH-SY5Y cells. Mechanistically, circBBS2 sponged miR-494 to enhance the SLC7A11 level. Knockdown of miR-494 or SLC7A11 reversed the effects of silencing circBBS2 or miR-494 on ferroptosis of SH-SY5Y cells, respectively. Furthermore, UC-MSCs-derived exosomes attenuated ischemic stroke in rats via delivering circBBS2 to inhibit ferroptosis. UC-MSCs-derived exosomal circBBS2 enhanced SLC7A11 expression via sponging miR-494, therefore repressing ferroptosis and relieving ischemic stroke. Our findings shed light on a novel mechanism for UC-MSCs-derived exosomes in the treatment of ischemic stroke.

A ferroptosis-related gene in Helicobacter pylori infection, SOCS1, serves as a potential prognostic biomarker and corresponds with tumor immune infiltration in stomach adenocarcinoma: In silico approach

OBJECTIVE

Helicobacter pylori (H. pylori) is a major risk factor for the stomach adenocarcinoma (STAD). This study aimed to investigate the potential role of a H. pylori infection-related gene, SOCS1, in STAD.

MATERIALS AND METHODS

Online available databases were analyzed to determine the expression, correlations with clinicopathologic parameters, patients' survival, and immunological characteristics of SOCS1 in TCGA-STAD or GEO datasets. Univariate and multivariate Cox regression analyses were used to determine independent risk factors, which were further integrated to establish a nomogram. A comparison of drug sensitivity was conducted for the chemotherapy responses between individuals with low- and high-SOCS1. Prediction of tumor response to checkpoint inhibitors was based on the tumor immunodeficiency and exclusion (TIDE) score.

RESULTS

SOCS1 expression was significantly increased in both H. pylori-infected and STAD patients. Higher SOCS1 expression indicated an undesirable prognosis in STAD patients. SOCS1 upregulation was related to enhanced immune cell infiltrations and the upregulation of immune checkpoints in STAD patients. N stage, age and SOCS1 were identified as independent risk factors for higher mortality of STAD patients and confirmed using the nomogram. Drug sensitivity analyses demonstrated that high expression of SOCS1 in STAD patients could improve the sensitivity to chemotherapy. TIDE score showed that STAD patients with high SOCS1 expression would have superior response to immunotherapy.

CONCLUSIONS

SOCS1 may act as a potential biomarker for uncovering the underlying mechanisms of gastric cancer. Increasing the activity of immunotherapy through ferroptosis-immunomodulation may be a viable strategy in STAD therapy.

Arenobufagin causes ferroptosis in human gastric cancer cells by increasing rev-erbα expression

Background and aims

Gastric cancer is the fifth most diagnosed malignant tumor worldwide with limited effective chemotherapy. Ferroptosis is a new type of programmed cell death, which is becoming as a novel therapeutic target for tumors. Arenobufagin (ArBu) is a bufadienolide isolated from toad skin and venom, which exhibits broad-spectrum anti-tumor activity. It is unclear whether ArBu causes ferroptosis, thereby exhibiting anti-tumor activity in gastric cancer. We aimed to determine whether ArBu causes ferroptosis in cultured human gastric cancer cells.

Experimental procedure

Different human gastric cancer cells were treated with ArBu (5-20 μM, 48 h). Indicators of apoptosis and ferroptosis were measured. CRISPR/Cas-9 system was employed to delete Nr1d1 gene.

Results

ArBu incubation reduced cell viability in a concentration-dependent manner. ArBu caused ferroptosis but not apoptosis at a lower concentration (10 μM), despite it caused both of them at a higher concentration (20 μM). Cotreatment with a selective ferroptosis inhibitor ferrostatin-1 protected against ArBu (10 μM)-induced reduction in cell viability. ArBu-mediated ferroptosis was associated with abnormal expression of genes involved in iron uptake, lipid peroxidation, and antioxidants. Particularly, Nr1d1 gene expression was most significantly increased after ArBu treatment. Furthermore, activating Rev-erbα encoded by Nr1d1 by a selective agonist GSK4112 (1 and 2 μM, 48 h) caused ferroptosis. In contrast, Rev-erbα knockout using the CRISPR/Cas-9 system diminished ArBu-induced ferroptosis in cultured human gastric cancer cells.

Conclusion

ArBu causes ferroptosis by increasing Rev-erbα expression in human gastric cancer cells. This has implications of ArBu as a promising therapy for gastric cancer.

Section

1. Natural Products.

Taxonomy classification by EVISE

Traditional medicine, pharmacology, gastric cancer, signal pathway.

Role of ferroptosis and ferroptosis-related non-coding RNAs in the occurrence and development of gastric cancer

Gastric cancer (GC) is a malignant cancer of the digestive tract and is a life-threatening disease worldwide. Ferroptosis is a newly discovered form of regulated cell death, which involves the accumulation of iron-dependent lipid peroxides. It has been found that ferroptosis plays an important regulatory role in the occurrence, development, drug resistance, and prognosis of GC. Non-coding RNAs (ncRNAs) play a critical role in the occurrence and progression of a variety of diseases including GC. In recent years, the role of ferroptosis and ferroptosis-related ncRNAs (miRNA, lncRNA, and circRNA) in the occurrence, development, drug resistance, and prognosis of GC has attracted more and more attention. Herein, we briefly summarize the roles and functions of ferroptosis and ferroptosis-related ncRNAs in GC tumorigenesis, development, and prognosis. We also prospected the future research direction and challenges of ferroptosis and ferroptosis-related ncRNAs in GC.

Ferroptosis and its Role in Gastric Cancer

Gastric cancer (GC) is the fifth most common cancer and the third leading cause of cancer-related deaths worldwide. Currently, surgery is the treatment of choice for GC. However, the associated expenses and post-surgical pain impose a huge burden on these patients. Furthermore, disease recurrence is also very common in GC patients, thus necessitating the discovery and development of other potential treatment options. A growing body of knowledge about ferroptosis in different cancer types provides a new perspective in cancer therapeutics. Ferroptosis is an iron-dependent form of cell death. It is characterized by intracellular lipid peroxide accumulation and redox imbalance. In this review, we summarized the current findings of ferroptosis regulation in GC. We also tackled on the action of different potential drugs and genes in inducing ferroptosis for treating GC and solving drug resistance. Furthermore, we also explored the relationship between ferroptosis and the tumor microenvironment in GC. Finally, we discussed areas for future studies on the role of ferroptosis in GC to accelerate the clinical utility of ferroptosis induction as a treatment strategy for GC.

Expression of ferroptosis-related gene correlates with immune microenvironment and predicts prognosis in gastric cancer

The study is to explore the role of ferroptosis-related genes (FRGs) in the occurrence and development of gastric cancer (GC), and to construct a new prognosis signature to predict the prognosis in GC. Clinical information and corresponding RNA data of GC patients were downloaded from TCGA and GEO databases. Consensus clustering was performed to identify new molecular subgroups. ESTIMATE, CIBERSORT, McpCounter and TIMER algorithm were used to analyze the infiltration of immune cells in two molecular subgroups. LASSO algorithm and multivariate Cox analysis were used to construct a prognostic risk signature. Functional analysis was conducted to elucidate the underlying mechanisms. Finally, the FRPGs were verified by Quantitative Real-Time PCR. We obtained 16 FRGs and divided GC patients into two subgroups by consistent clustering. Cluster C1 with a higher abundance of immune cell infiltration but lower probability in response to immunotherapy, it was reasonable to speculate that Cluster C1 was in accordance with the immune rejection type. Functional analysis showed that the biological process of DEGs in training cohort mainly included immune globulin, and human immune response mediated by circulating immune globulin. GSEA analysis showed that compared with Cluster C2, Cluster C1 showed lower expression in lipid metabolism. The nomogram combined with risk signature and clinical features can accurately predict the prognosis of GC patients. We identified two molecular subtypes, Clusters C1 and C2. In Cluster C1, patients with poor prognosis present with a hyperimmune status and low lipid metabolism, and we speculate that Cluster C1 was in accordance with the immune rejection type. The risk model based on FRPGs can accurately predict the prognosis of GC. These results indicated that ferroptosis is associated with TIME, and deserved considerable attention in determining immunotherapy treatment strategy for GC patients.