Ferroptosis and its emerging role in esophageal cancer

[Research progress of iron metabolism and ferroptosis in myeloid neoplasms]

It is reported that iron metabolism and ferroptosis can influence the occurrence and development of myeloid tumors, which can serve as therapeutic targets. Dysregulation of iron metabolism is present in a variety of myeloid neoplasms. The prognosis of acute myeloid leukemia is related to differential expression of molecules related to iron metabolism. The prognosis of myelodysplastic syndrome patients with iron overload is poor. Myeloproliferative neoplasms are often characterized by the coexistence of iron deficiency and erythrocytosis, which can be treated by targeting hepcidin. Myeloid tumor cells are susceptible to oxidative damage caused by the accumulation of reactive oxygen species and are sensitive to ferroptosis. Ferroptosis has anti-tumor effect in acute myeloid leukemia and myelodysplastic syndrome. Targeting ferroptosis can reverse imatinib resistance in chronic myeloid leukemia. This article reviews the characteristics of iron metabolism in the development and progression of myeloid neoplasms, as well as the mechanism of ferroptosis, to provide a basis for the development of new therapeutic strategies.

Progress in research of ferroptosis in gastrointestinal tumors

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

[Ferroptosis suppressor genes are highly expressed in esophageal cancer to inhibit tumor cell ferroptosis]

OBJECTIVE

To explore the role of ferroptosis-related genes in regulating ferroptosis of esophageal squamous cell carcinoma (ESCC).

METHODS

ESCC datasets GSE161533 and GSE20347 were downloaded from the Gene Expression Omnibus (GEO) to identify the differentially expressed genes (DEGs) using R software. ESCC ferroptosis-related genes obtained by intersecting the DEGs with ferroptosis-related genes from FerrDb were analyzed using GO and KEGG analyses, protein-protein interaction (PPI) network analysis, and core gene identification through Cytoscape. The identified ferroptosis suppressor genes were validated using TCGA database, and their expression levels were detected using RT-qPCR in cultured normal esophageal cells and ESCC cells. Six ferroptosis suppressor genes (RRM2, GCLC, TFRC, TXN, SLC7A11, and EZH2) were downregulated with siRNA in ESCC cells, and the changes in cell proliferation and apoptosis were assessed with CCK8 assay and flow cytometry; Western blotting was performed to examine the changes in ferroptosis progression of the cells.

RESULTS

We identified a total of 58 ESCC ferroptosis-related genes, which involved such biological processes as glutathione transmembrane transport, iron ion transport, and apoptosis and the ferroptosis, glutathione metabolism, and antifolate resistance pathways. The PPI network included 54 nodes and 74 edges with a clustering coefficient of 0.522 and PPI enrichment P<0.001. Cytoscape identified 6 core ferroptosis suppressor genes (RRM2, TFRC, TXN, EZH2, SLC7A11, and GCLC), which were highly expressed in ESCC tissues in the TCGA dataset and in ESCC cell lines. Downregulating these genes in ESCC TE1 cells significantly inhibited cell proliferation, promoted cell apoptosis, reduced the expression levels of ferroptosis markers GPX4 and FIH1, and increased the expression of ACSL4.

CONCLUSION

High expression of ferroptosis suppressor genes in ESCC may cause arrest of ferroptosis progression to facilitate tumor development, and inhibiting these genes can restore ferroptosis and promote cell apoptosis, suggesting their value as potential therapeutic targets for ESCC.

Emerging mechanisms of ferroptosis and its implications in lung cancer

ABSTRACT

Lung cancer is one of the most common malignancies and has the highest number of deaths among all cancers. Despite continuous advances in medical strategies, the overall survival of lung cancer patients is still low, probably due to disease progression or drug resistance. Ferroptosis is an iron-dependent form of regulated cell death triggered by the lethal accumulation of lipid peroxides, and its dysregulation is implicated in cancer development. Preclinical evidence has shown that targeting the ferroptosis pathway could be a potential strategy for improving lung cancer treatment outcomes. In this review, we summarize the underlying mechanisms and regulatory networks of ferroptosis in lung cancer and highlight ferroptosis-targeting preclinical attempts to provide new insights for lung cancer treatment.

Inhibition of Apoc1 reverses resistance of sorafenib by promoting ferroptosis in esophageal cancers

Drug resistance is an obstacle in therapy of esophageal cancers (ECs), and the role of ferroptosis in progression ECs is still not clearly clarified. In the present study, we investigated the role of Apolipoprotein C1 (Apoc1) in regulating the sorafenib resistance in EC cells. Apoc1 was knock down after infection with Apoc1 shRNA lentivirus and stable cell lines for Apoc1 knockdown were screened. Cell viabilities were tested by MTT assay. ROS, MDA, and GSH tested by specific kits. In vivo experiment in nude mice were performed to test the correlation of Apoc1 and ferroptosis. The expression of Apoc1 and GPX4 was tested by western blotting. The results showed that Apoc1 was highly expressed in EC tissues and associated with poor overall survival rate of EC. Knockdown Apoc1 overcame resistance of sorafenib in EC cells and promoted erastin and sorafenib induced ferroptosis by upregulating the levels of ROS and MDA and downregulating the level of GSH in OE19/Sora and EC109/Sora cells. Rescue experiments proved that Apoc1 regulated sorafenib induced ferroptosis via GPX4. Furthermore, knockdown of Apoc1 inhibited the tumor progression by promoting ferroptosis in nude mice. In conclusion, knockdown Apoc1 overcome resistance of sorafenib in EC cells and in vivo by promoting sorafenib induced ferroptosis via GPX4. Targeting Apoc1 might be an effective way to reverse the drug resistance of sorafenib via inducing ferroptosis in EC progression.

A ferroptosis-related LncRNAs signature for predicting prognoses and screening potential therapeutic drugs in patients with lung adenocarcinoma: A retrospective study

BACKGROUND

Lung adenocarcinoma (LUAD) has a high mortality rate. Ferroptosis is linked to tumor initiation and progression.

AIMS

This study aims to develop prognostic models of ferroptosis-related lncRNAs, evaluate the correlation between differentially expressed genes and tumor microenvironment, and identify prospective drugs for managing LUAD.

METHODS AND RESULTS

In this study, transcriptomic and clinical data were downloaded from the TCGA database, and ferroptosis-related genes were obtained from the FerrDb database. Through correlation analysis, Cox analysis, and the LASSO algorithm for constructing a prognostic model, we found that ferroptosis-related lncRNA-based gene signatures (FLncSig) had a strong prognostic predicting ability in the LUAD patients. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichments reconfirmed that ferroptosis is related to receptor-ligand activity, enzyme inhibitor activity, and the IL-17 signaling pathway. Next, tumor mutation burden (TMB), tumor immune dysfunction and exclusion (TIDE) algorithms, and pRRophetic were used to predict immunotherapy response and chemotherapy sensitivity. The IMvigor210 cohort was also used to validate the prognostic model. In the tumor microenvironment, Type_II_IFN_Response and HLA were found to be a group of low-risk pathways, while MHC_class_I was a group of high-risk pathways. Patients in the high-risk subgroup had lower TIDE scores. Exclusion, MDSC, CAF, and TAMM2 were significantly and positively correlated with risk scores. In addition, we found 15 potential therapeutic drugs for LUAD. Finally, differential analysis of stemness index based on mRNA expression (mRNAsi) indicated that mRNAsi was correlated with gender, primary tumor (T), distant metastasis (M), and the tumor, node, and metastasis (TNM) stage in LUAD patients.

CONCLUSIONS

In conclusion, the prognostic model based on FLncSig can alleviate the difficulty in predicting the prognosis and immunotherapy of LUAD patients. The identified FLncSig and the screened drugs exhibit potential for clinical application and provide references for the treatment of LUAD.

Unraveling the Complexity of Regulated Cell Death in Esophageal Cancer: from Underlying Mechanisms to Targeted Therapeutics

Esophageal cancer (EC) is the sixth most common and the seventh most deadly malignancy of the digestive tract, representing a major global health challenge. Despite the availability of multimodal therapeutic strategies, the existing EC treatments continue to yield unsatisfactory results due to their limited efficacy and severe side effects. Recently, knowledge of the subroutines and molecular mechanisms of regulated cell death (RCD) has progressed rapidly, enhancing the understanding of key pathways related to the occurrence, progression, and treatment of many types of tumors, including EC. In this context, the use of small-molecule compounds to target such RCD subroutines has emerged as a promising therapeutic strategy for patients with EC. Thus, in this review, we firstly discussed the risk factors and prevention of EC. We then outlined the established treatment regimens for patients with EC. Furthermore, we not only briefly summarized the mechanisms of five best studied subroutines of RCD related to EC, including apoptosis, ferroptosis, pyroptosis, necroptosis and autophagy, but also outlined the recent advances in the development of small-molecule compounds and long non-coding RNA (lncRNA) targeting the abovementioned RCD subroutines, which may serve as a new therapeutic strategy for patients with EC in the future.

Basic mechanisms and novel potential therapeutic targets for ferroptosis in acute myeloid leukemia

Ferroptosis is a form of cell death that is regulated by iron and characterized by the buildup of lipid peroxides (LPO) and subsequent rupture of the cell membrane. The molecular mechanisms of ferroptosis involve metabolic pathways related to iron, lipids, and amino acids, which contribute to the production of lipid reactive oxygen species (ROS). In recent years, there has been increasing attention on the occurrence of ferroptosis in various diseases. Ferroptosis has been found to play a crucial role in cardiovascular diseases, digestive diseases, respiratory and immunological diseases, and particularly in malignancies. However, there is still a lack of studies on ferroptosis in acute myeloid leukemia (AML). This paper provides a comprehensive review of the mechanism of ferroptosis and its regulatory molecules and therapeutic agents in AML. It also evaluates the relationship between ferroptosis-related genes (FRGs), non-coding RNAs (ncRNAs), and prognosis to develop prognostic molecular models in AML. The study also explores the association between ferroptosis and immune infiltration in AML, to identify novel potential target regimens for AML.