Effect of tumor microenvironment on ferroptosis: inhibition or promotion

Ferroptosis: CD8+T cells' blade to destroy tumor cells or poison for self-destruction

Ferroptosis represents an emerging, iron-dependent form of cell death driven by lipid peroxidation. In recent years, it has garnered significant attention in the realm of cancer immunotherapy, particularly in studies involving immune checkpoint inhibitors. This form of cell death not only enhances our comprehension of the tumor microenvironment but is also considered a promising therapeutic strategy to address tumor resistance, investigate immune activation mechanisms, and facilitate the development of cancer vaccines. The combination of immunotherapy with ferroptosis provides innovative targets and fresh perspectives for advancing cancer treatment. Nevertheless, tumor cells appear to possess a wider array of ferroptosis evasion strategies compared to CD8+T cells, which have been conclusively shown to be more vulnerable to ferroptosis. Furthermore, ferroptosis in the TME can create a favorable environment for tumor survival and invasion. Under this premise, both inducing tumor cell ferroptosis and inhibiting T cell ferroptosis will impact antitumor immunity to some extent, and even make the final result run counter to our therapeutic purpose. This paper systematically elucidates the dual-edged sword role of ferroptosis in the antitumor process of T cells, briefly outlining the complexity of ferroptosis within the TME. It explores potential side effects associated with ferroptosis-inducing therapies and critically considers the combined application of ferroptosis-based therapies with ICIs. Furthermore, it highlights the current challenges faced by this combined therapeutic approach and points out future directions for development.

TRPV4 as a Novel Regulator of Ferroptosis in Colon Adenocarcinoma: Implications for Prognosis and Therapeutic Targeting

BACKGROUND

Colon adenocarcinoma (COAD) is a leading cause of cancer-related mortality worldwide. Transient receptor potential vanilloid 4 (TRPV4), a calcium-permeable non-selective cation channel, has been implicated in various cancers, including COAD. This study investigates the role of TRPV4 in colon adenocarcinoma and elucidates its potential mechanism via the ferroptosis pathway.

MATERIALS AND METHODS

Gene expression profiles and clinical data were obtained from The Cancer Genome Atlas (TCGA), encompassing 647 colon adenocarcinoma tissue samples and 51 normal colorectal tissue samples. Ferroptosis-related genes were retrieved from the FerrDb database. Differential expression analysis, survival analysis, and Cox proportional hazards regression were performed to assess the prognostic significance of TRPV4. Protein-protein interaction networks and gene enrichment analyses (GO and KEGG) were conducted to explore functional associations. In vitro experiments were carried out using HT-29 and SW480 colon cancer cell lines. TRPV4 was knocked down using siRNA, and cell viability was assessed via hematoxylin and eosin (HE) staining. Immunofluorescence assays evaluated the expression of ferroptosis-related proteins (SLC3A2, GPX4) and proliferation markers (KI67, SRC, CTNNB1, COL1).

RESULTS

TRPV4 expression was significantly elevated in colon adenocarcinoma tissues compared to normal tissues (p < 0.05), demonstrating high diagnostic accuracy (AUC = 0.848). High TRPV4 expression correlated with poorer overall survival (OS) and disease-specific survival (DSS), particularly in patients over 65 years old and those in clinical stage II. Cox regression analysis confirmed TRPV4 as an independent prognostic factor (HR = 1.395, p = 0.074). Bioinformatics analyses revealed that TRPV4 is closely associated with ferroptosis-related genes, participating in key biological processes such as responses to external stimuli, oxidative stress, and cell adhesion. In vitro, TRPV4 knockdown significantly reduced cell viability (p < 0.05) and decreased expression levels of SLC3A2, GPX4, KI67, SRC, and COL1 (p < 0.05). The addition of the ferroptosis inhibitor FER-1 did not restore cell viability in TRPV4 knockdown cells, suggesting that TRPV4 modulates cell survival through the ferroptosis pathway.

DISCUSSION

The bioinformation and in vitro experiments inTRPV4 and ferroptosis-related genes support the hypothesis that TRPV4 influences tumor cell survival via the ferroptosis pathway. The inability of FER-1 to rescue viability in TRPV4-deficient cells further confirms this mechanism. These findings provide novel insights into the molecular mechanisms of COAD and highlight TRPV4 as a potential therapeutic target.

CONCLUSION

TRPV4 is significantly upregulated in COAD and is associated with unfavorable patient outcomes. It appears to promote tumor progression by regulating the ferroptosis pathway, affecting the expression of key ferroptosis-related genes and proliferation markers. Targeting TRPV4 may offer a new therapeutic approach for COAD, and further research is warranted to explore its role in other cancers and to develop TRPV4-based therapies.

Ferroptosis in Pulmonary Disease and Lung Cancer: Molecular Mechanisms, Crosstalk Regulation, and Therapeutic Strategies

Ferroptosis is a distinct form of iron-dependent programmed cell death characterized primarily by intracellular iron accumulation and lipid peroxidation. Multiple cellular processes, including amino acid metabolism, iron metabolism, lipid metabolism, various signaling pathways, and autophagy, have been demonstrated to influence the induction and progression of ferroptosis. Recent investigations have elucidated that ferroptosis plays a crucial role in the pathogenesis of various pulmonary disorders, including lung injury, chronic obstructive pulmonary disease, pulmonary fibrosis, and asthma. Ferroptosis is increasingly recognized as a promising novel strategy for cancer treatment. Various immune cells within the tumor microenvironment, including CD8+ T cells, macrophages, regulatory T cells, natural killer cells, and dendritic cells, have been shown to induce ferroptosis in tumor cells and modulate the process through the regulation of iron and lipid metabolism pathways. Conversely, ferroptosis can reciprocally alter the metabolic environment, leading to the activation or inhibition of immune cell functions, thereby modulating immune responses. This paper reviews the molecular mechanism of ferroptosis and describes the tumor immune microenvironment, discusses the connection between ferroptosis and the tumor microenvironment in lung cancer and pulmonary diseases, and discusses the development prospect of their interaction in the treatment of lung cancer and pulmonary diseases.

Current knowledge of ferroptosis in the pathogenesis and prognosis of oral squamous cell carcinoma

Therapeutic strategies are the hot-spot issues in treating patients with advanced oral squamous cell carcinoma (OSCC). Mounting studies have proved that triggering ferroptosis is one of the promising targets for OSCC management. In this study, we performed a first attempt to collect the current evidence on the proposed roles of ferroptosis in OSCC through a comprehensive review. Based on clinical data from the relevant studies within this topic, we found that ferroptosis-associated tumor microenvironment, ferroptosis-related genes (FRGs), and ferroptosis-related lncRNAs exhibited a potent prognostic value for OSCC patients. Mechanistically, experimental data revealed that the proliferation and tumorigenesis of OSCC might be associated with the inhibition of cellular ferroptosis through the activation of glutathione peroxidase 4 (GPX4) and adipocyte enhancer-binding protein 1 (AEBP1), suppression of glutathione (GSH) and Period 1 (PER1) expression, and modulation of specific non-coding RNAs (i.e., miR-520d-5p, miR-34c-3p, and miR-125b-5p) and their targeted proteins. Several specific interventions (i.e., Quisinostat, Carnosic acid, hyperbaric oxygen, melatonin, aqueous-soluble sporoderm-removed G. lucidum spore powder, and disulfiram/copper complex) were found to dramatically induce ferroptosis cell death of OSCC via multiple mechanisms. This review highlighted the pivotal role of ferroptosis in the pathogenesis and prognosis of OSCC. Future anticancer therapeutic strategies targeting ferroptosis and its associated molecules might provide a new insight for OSCC treatment.

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.

Interplay of Ferroptosis and Cuproptosis in Cancer: Dissecting Metal-Driven Mechanisms for Therapeutic Potentials

Iron (Fe) and copper (Cu), essential transition metals, play pivotal roles in various cellular processes critical to cancer biology, including cell proliferation, mitochondrial respiration, distant metastases, and oxidative stress. The emergence of ferroptosis and cuproptosis as distinct forms of non-apoptotic cell death has heightened their significance, particularly in connection with these metal ions. While initially studied separately, recent evidence underscores the interdependence of ferroptosis and cuproptosis. Studies reveal a link between mitochondrial copper accumulation and ferroptosis induction. This interconnected relationship presents a promising strategy, especially for addressing refractory cancers marked by drug tolerance. Harnessing the toxicity of iron and copper in clinical settings becomes crucial. Simultaneous targeting of ferroptosis and cuproptosis, exemplified by the combination of sorafenib and elesclomol-Cu, represents an intriguing approach. Strategies targeting mitochondria further enhance the precision of these approaches, providing hope for improving treatment outcomes of drug-resistant cancers. Moreover, the combination of iron chelators and copper-lowering agents with established therapeutic modalities exhibits a synergy that holds promise for the augmentation of anti-tumor efficacy in various malignancies. This review elaborates on the complex interplay between ferroptosis and cuproptosis, including their underlying mechanisms, and explores their potential as druggable targets in both cancer research and clinical settings.