SLC7A11: the Achilles heel of tumor?

Ferroptosis and renal fibrosis: mechanistic insights and emerging therapeutic targets

Ferroptosis is a regulated, iron-dependent form of cell death driven by lipid peroxidation and distinct from apoptosis, necroptosis, and pyroptosis. Recent studies implicate ferroptosis as a central contributor to the pathogenesis of renal fibrosis, a hallmark of chronic kidney disease associated with high morbidity and progression to end-stage renal failure. This review synthesizes current evidence linking ferroptotic signaling to fibrotic remodeling in the kidney, focusing on iron metabolism dysregulation, glutathione peroxidase 4 (GPX4) inactivation, lipid peroxide accumulation, and ferroptosis-regulatory pathways such as FSP1-CoQ10-NAD(P)H and GCH1-BH4. We detail how ferroptosis in tubular epithelial cells modulates pro-fibrotic cytokine release, macrophage recruitment, and TGF-β1-driven extracellular matrix deposition. Moreover, we explore ferroptosis as a therapeutic vulnerability in renal fibrosis, highlighting promising agents including iron chelators, GPX4 activators, anti-lipid peroxidants, and exosome-based gene delivery systems. By consolidating emerging preclinical data, this review provides a comprehensive mechanistic framework and identifies translational opportunities for targeting ferroptosis in fibrotic kidney disease.

Disulfide bond-related gene signature development for bladder cancer prognosis prediction and immune microenvironment characterization

Bladder cancer is the fourth most common malignant tumor in men, with limited therapeutic biomarkers and heterogeneous responses to immunotherapy. Disulfide bond-driven cell death has emerged as a critical regulator of tumor progression and immune microenvironment remodeling. By integrating data from TCGA and GEO cohorts, we developed a Disulfide-Related Prognostic Signature (DRPS) using ten machine learning algorithms. Single-cell RNA sequencing (scRNA-seq) elucidated the cell subtype-specific expression patterns of disulfide bond regulatory genes, while immune microenvironment and drug sensitivity analyses validated its clinical translational potential. qRT-PCR experiments confirmed differential expression patterns of core genes in bladder cancer cell lines. The DRPS model, optimized by the StepCox[backward] algorithm, demonstrated robust prognostic accuracy across four validation cohorts (mean C-index = 0.658). High-risk patients exhibited an enhanced immunosuppressive microenvironment characterized by infiltrated activated cancer-associated fibroblasts, upregulated APC co-inhibition pathways, and elevated immune checkpoint expression. Notably, high DRPS scores were associated with primary resistance to immunotherapy but showed increased sensitivity to anti-tumor agents such as Elephantine and Leflunomide. This study establishes a novel DRPS that serves as a predictive indicator for bladder cancer prognosis and pan-cancer immunotherapy efficacy.

The Development and Assessment of a Unique Disulfidptosis-Associated lncRNA Profile for Immune Microenvironment Prediction and Personalized Therapy in Gastric Adenocarcinoma

Background: Long non-coding RNAs (lncRNAs) are crucial factors affecting the occurrence, progression, and prognosis of gastric carcinoma (GC). The accumulation of disulfide bonds to excessive levels in cells expressing high SLC7A11 triggers disulfidptosis, which functions as a regulated form of cellular death. Research has demonstrated that upregulated SLC7A11 is common in human cancers, but the effect of disulfidptosis on GC remains unclear. Identifying lncRNAs associated with disulfidptosis (drlncRNAs) and establishing a prognostic risk profile holds considerable importance for advancing GC research and treatment. Methods: Clinical records and transcriptomic datasets from individuals with GC were acquired from The Cancer Genome Atlas (TCGA) repository. A three-drlncRNA risk model was built using three common regression analysis methods. Then we used receiver operating characteristic (ROC) curves, independent prognostic analysis, and additional statistical approaches to assess the precision of the model. This investigation additionally encompassed Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, immune cell infiltration evaluation, and pharmacological sensitivity predictions. To further investigate immunotherapy response disparities between patient cohorts with elevated- and reduced-risk scores, analyses of tumor mutational burden (TMB), tumor immune dysfunction and exclusion (TIDE), and microsatellite instability (MSI) were implemented. Results: We constructed a unique model composed of three drlncRNAs (AC107021.2, AC016394.2, and AC129507.1). Its independent prognostic capability for GC patients was validated through both single-variable and multivariable Cox regression analyses. GO and KEGG pathway assessments revealed predominant enrichment within the elevated-risk cohort, particularly in pathways involving sulfur compound interactions, traditional Wnt signaling mechanisms, cell-substrate adherens junctions, and cAMP signaling cascades, among others. Tumor microenvironment (TME) evaluation demonstrated elevated ImmuneScores, StromalScores, and ESTIMATEScores within the high-risk patient population. Concurrently, this elevated-risk cohort exhibited enhanced immune cell infiltration patterns, whereas the reduced-risk group displayed superior expression of immune checkpoints (ICPs). Additional investigations revealed that patients categorized into the reduced-risk classification possessed greater tumor mutational burden, increased MSI-high proportions, and diminished tumor immune dysfunction and exclusion scores compared to their high-risk counterparts. Pharmacological sensitivity assessments confirmed the superior efficacy of several therapeutic agents, including gemcitabine and veliparib (ABT.888), in patients with lower risk classifications. Conclusions: Our established risk stratification system demonstrates independent prognostic predictive capacity while offering personalized clinical intervention guidance for individuals diagnosed with GC.

cDTL contributes to breast cancer progression through regulating redox homeostasis via affecting the function of system xc. Biochem Biophys Res Commun 2025;744:151196. [PMID: 39706052 DOI: 10.1016/j.bbrc.2024.151196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Ferroptosis is a new type of cell death caused by redox imbalance mediated by iron-dependent lipid peroxidation, which is intimately linked to human disease. Circular RNA, characterized by covalently closed loop structure, has attracted much attention due to its involvement in various biological functions. However, little is known about the role of circRNA in ferroptosis. In this study, we identified cDTL (a circular RNA derived from DTL gene) as a ferroptosis-related circRNA. cDTL expression was remarkably elevated by ferroptotic stress. Knockdown of cDTL significantly inhibited breast cancer cell growth both in vitro and in vivo through promoting ferroptosis. Mechanistically, cDTL directly bound to NRF2 and BCLAF1 in the nucleus and cytoplasm, respectively, resulting in transcriptional activation and mRNA stability of SLC7A11 (the core subunit of system Xc-), thereby repressing ferroptosis via activating GSH/GPX4 axis. Moreover, cDTL was identified as a direct transcriptional target of Myc, a well-known protooncogene that is highly activated in breast cancer. More importantly, cDTL was overexpressed in human breast cancer tissues, which was associated with dismal progression-free survival and poor differentiation. In conclusion, our data suggest that cDTL is a novel regulator of ferroptosis, targeting cDTL may be a potential therapeutic strategy for breast cancer.

Decoding ferroptosis: transforming orthopedic disease management

As a mechanism of cell death, ferroptosis has gained popularity since 2012. The process is distinguished by iron toxicity and phospholipid accumulation, in contrast to autophagy, apoptosis, and other cell death mechanisms. It is implicated in the advancement of multiple diseases across the body. Researchers currently know that osteosarcoma, osteoporosis, and other orthopedic disorders are caused by NRF2, GPX4, and other ferroptosis star proteins. The effective relief of osteoarthritis symptoms from deterioration has been confirmed by clinical treatment with multiple ferroptosis inhibitors. At the same time, it should be reminded that the mechanisms involved in ferroptosis that regulate orthopedic diseases are not currently understood. In this manuscript, we present the discovery process of ferroptosis, the mechanisms involved in ferroptosis, and the role of ferroptosis in a variety of orthopedic diseases. We expect that this manuscript can provide a new perspective on clinical diagnosis and treatment of related diseases.

Intracellular Iron Deficiency and Abnormal Metabolism, Not Ferroptosis, Contributes to Homocysteine-Induced Vascular Endothelial Cell Death

Background/Objectives: Homocysteine (Hcy) and iron are factors co-related with the progression of cardiovascular diseases. The vascular endothelium is an important barrier for physiological homeostasis, and its impairment initiates cardiovascular injury. However, the mechanism underlying Hcy-caused vascular endothelial cell injury and the participation of iron are not fully elucidated. This study aims to investigate the Hcy-induced vascular endothelial injury and iron metabolism dysfunction as well as the underlying molecular mechanism. Methods: Human umbilical vein endothelial cells (HUVECs) were employed as the experimental model to examine the Hcy-induced endothelial injury and its underlying mechanism via various biochemical assays. Results: Hcy suppressed the cell viability and proliferation and caused cell death in a concentration-dependent manner. Hcy induced cell cycle arrest, apoptosis, and autophagy as well as impairment of intracellular energy metabolism. Hcy disrupted the intracellular antioxidant system and mitochondrial function by increasing intracellular ROS, MDA and mitochondrial content, and decreasing the SOD activity and mitochondrial membrane potential. Hcy significantly reduced the GSH-Px activity along with the accumulation of intracellular GSH in a concentration-dependent manner. Ferroptosis inhibitors, Ferrostatin-1 (Fer-1), and Deferoxamine (DFO) significantly decreased the Hcy-caused cytotoxicity accompanied by a reduction in dysregulated mitochondria content, but only DFO ameliorated the elevation of intracellular ROS, and neither Fer-1 nor DFO affected the Hcy-caused reduction in intracellular ATP. In addition, Hcy decreased the intracellular concentration of iron, and supplementing Hcy with various concentrations of Fe3+ increased the cell viability and decreased the LDH release in a concentration-dependent manner. Hcy dramatically decreased the mRNA expression level of transferrin receptor while increasing the mRNA expression levels of transferrin, ferritin light chain, ferritin heavy chain, ferroportin, and SLC7A11. Moreover, Hcy suppressed the protein expression of phospho-Akt, phospho-mTOR, Beclin-1, LC3A/B, Nrf2, HO-1, phospho-MEK1/2, phospho-ERK1/2, and Caspase-3 in concentration- and time-dependent manners. Conclusions: Hcy-induced vascular endothelial injury is likely to be associated with apoptosis and autophagy, but not ferroptosis. The key underlying mechanisms are involved in the disruption of the intracellular antioxidant system and iron metabolism via regulation of PI3K/Akt/mTOR, MAPKs, Nrf2/HO-1, and iron metabolism.

Formononetin triggers ferroptosis in triple-negative breast cancer cells by regulating the mTORC1/SREBP1/SCD1 pathway

Introduction

Triple-negative breast cancer (TNBC) is the most malignant type of breast cancer, and its prognosis is still the worst. It is necessary to constantly explore the pathogenesis and effective therapeutic targets of TNBC. Formononetin is an active ingredient with anti-tumor effects that we screened earlier. The main purpose of this study is to elucidate mechanism of the inhibitory effect of Formononetin on TNBC.

Methods

We conducted experiments through both in vivo and in vitro methodologies. The in vivo experiments utilized a nude mice xenotransplantation model, while the in vitro investigations employed two breast cancer cell lines, MDA-MB-231 and MDA-MB-468. Concurrently, ferroptosis associated proteins, lipid peroxide levels, and proteins related to the rapamycin complex 1 were analyzed in both experimental settings.

Results

In our study, Formononetin exhibits significant inhibitory effects on the proliferation of triple TNBC, both in vivo and in vitro. Moreover, it elicits an increase in lipid peroxide levels, downregulates the expression of ferroptosis-associated proteins GPX4 and xCT, and induces ferroptosis in breast cancer cells. Concurrently, Formononetin impedes the formation of the mammalian target of rapamycin complex 1 (mTORC1) and suppresses the expression of downstream Sterol regulatory element-binding protein 1(SREBP1). The utilization of breast cancer cells with SREBP1 overexpression or knockout demonstrates that Formononetin induces ferroptosis by modulating the mTORC1-SREBP1 signaling axis.

Discussion

In conclusion, this study provides evidence that Formononetin exerts an anti-proliferative effect on triple-negative breast cancer by inducing ferroptosis. Moreover, the mTORC1-SREBP1 signal axis is identified as the primary mechanism through which formononetin exerts its therapeutic effects. These findings suggest that formononetin holds promise as a potential targeted drug for clinical treatment of TNBC.