Emerging mechanisms and targeted therapy of ferroptosis in cancer

Exploration of potential biomarkers for early bladder cancer based on urine proteomics

Background

Bladder cancer is a common malignant tumor of the urinary system. The progression of the condition is associated with a poor prognosis, so it is necessary to identify new biomarkers to improve the diagnostic rate of bladder cancer.

Methods

In this study, 338 urine samples (144 bladder cancer, 123 healthy control, 32 cystitis, and 39 upper urinary tract cancer samples) were collected, among which 238 samples (discovery group) were analyzed by LC-MS. The urinary proteome characteristics of each group were compared with those of bladder cancer, and the differential proteins were defined by bioinformatics analysis. The pathways and functional enrichments were annotated. The selected proteins with the highest AUC score were used to construct a diagnostic panel. One hundred samples (validation group) were used to test the effect of the panel by ELISA.

Results

Compared with the healthy control, cystitis and upper urinary tract cancer samples, the number of differential proteins in the bladder cancer samples was 325, 158 and 473, respectively. The differentially expressed proteins were mainly related to lipid metabolism and iron metabolism and were involved in the proliferation, metabolism and necrosis of bladder cancer cells. The AUC of the panel of APOL1 and ITIH3 was 0.96 in the discovery group. ELISA detection showed an AUC of 0.92 in the validation group.

Conclusion

This study showed that urinary proteins can reflect the pathophysiological changes in bladder cancer and that important molecules can be used as biomarkers for bladder cancer screening. These findings will benefit the application of the urine proteome in clinical research.

Excessive SOX8 reprograms energy and iron metabolism to prime hepatocellular carcinoma for ferroptosis

Lipid peroxidation and redox imbalance are hallmarks of ferroptosis, an iron-dependent form of cell death. Growing evidence suggests that dysregulation in glycolipid metabolism and iron homeostasis substantially contribute to the development of hepatocellular carcinoma (HCC). However, there is still a lack of comprehensive understanding regarding the specific transcription factors that are capable of coordinating glycolipid and redox homeostasis to initiate the onset of ferroptosis. We discovered that overexpression of SOX8 leads to impaired mitochondria integrate, increased oxidative stress, and enhanced lipid peroxidation. These effects can be attributed to the inhibitory impact of SOX8 on de novo lipogenesis, glycolysis, the tricarboxylic acid cycle (TCA), and the pentose phosphate pathway (PPP). Additionally, upregulation of SOX8 results in reduced synthesis of NADPH, disturbance of redox homeostasis, disruption of mitochondrial structure, and impairment of the electron transport chain. Furthermore, the overexpression of SOX8 enhances the process of ferroptosis by upregulating the expression of genes associated with ferroptosis and elevating intracellular levels of ferrous ion. Importantly, the overexpressing of SOX8 has been observed to inhibit the proliferation of HCC in immunodeficient animal models. In conclusion, the findings suggest that SOX8 has the ability to alter glycolipid and iron metabolism of HCC cells, hence triggering the process of ferroptosis. The results of our study present a novel strategy for targeting ferroptosis in the therapy of HCC.

Ferroptosis in head and neck squamous cell carcinoma: from pathogenesis to treatment

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common malignant tumor worldwide, with high morbidity and mortality. Surgery and postoperative chemoradiotherapy have largely reduced the recurrence and fatality rates for most HNSCCs. Nonetheless, these therapeutic approaches result in poor prognoses owing to severe adverse reactions and the development of drug resistance. Ferroptosis is a kind of programmed cell death which is non-apoptotic. Ferroptosis of tumor cells can inhibit tumor development. Ferroptosis involves various biomolecules and signaling pathways, whose expressions can be adjusted to modulate the sensitivity of cells to ferroptosis. As a tool in the fight against cancer, the activation of ferroptosis is a treatment that has received much attention in recent years. Therefore, understanding the molecular mechanism of ferroptosis in HNSCC is an essential strategy with therapeutic potential. The most important thing to treat HNSCC is to choose the appropriate treatment method. In this review, we discuss the molecular and defense mechanisms of ferroptosis, analyze the role and mechanism of ferroptosis in the inhibition and immunity against HNSCC, and explore the therapeutic strategy for inducing ferroptosis in HNSCC including drug therapy, radiation therapy, immunotherapy, nanotherapy and comprehensive treatment. We find ferroptosis provides a new target for HNSCC treatment.

KCNA1 promotes the growth and invasion of glioblastoma cells through ferroptosis inhibition via upregulating SLC7A11

BACKGROUND

The high invasiveness and infiltrative nature of Glioblastoma (GBM) pose significant challenges for surgical removal. This study aimed to investigate the role of KCNA1 in GBM progression.

METHODS

CCK8, colony formation assay, scratch assay, transwell assay, and 3D tumor spheroid invasion assays were to determine how KCNA1 affects the growth and invasion of GBM cells. Subsequently, to confirm the impact of KCNA1 in ferroptosis, western blot, transmission electron microscopy and flow cytometry were conducted. To ascertain the impact of KCNA1 in vivo, patient-derived orthotopic xenograft models were established.

RESULTS

In functional assays, KCNA1 promotes the growth and invasion of GBM cells. Besides, KCNA1 can increase the expression of SLC7A11 and protect cells from ferroptosis. The vivo experiments demonstrated that knocking down KCNA1 inhibited the growth and infiltration of primary tumors in mice and extended survival time.

CONCLUSION

Therefore, our research suggests that KCNA1 may promote tumor growth and invasion by upregulating the expression of SLC7A11 and inhibiting ferroptosis, making it a promising therapeutic target for GBM.

Intracellular self-aggregation of biomimetic Fe3O4 nanoparticles for enhanced ferroptosis-inducing therapy of breast cancer

Nanomedicines based on ferroptosis may be effective strategies for cancer therapy due to their unique inducing mechanism. However, the challenges, including non-target distribution, poor accumulation and retention of nanomedicine, have a profound impact on the effectiveness of drug delivery. Here, we developed cancer cell membrane (CCM)-coated Fe3O4 nanoparticles (NPs) modified with supramolecular precursors and loaded with sulfasalazine (SAS) for breast cancer therapy. Benefiting from the coating of the CCM, these NPs can be specifically recognized and internalized by tumor cells rapidly after being administered and form aggregates via the host-guest interaction between adamantane (ADA) and cyclodextrins (CD), which in turn effectively reduces the exocytosis of tumor cells and prolongs the retention time. In vitro and in vivo studies showed that Fe3O4 NPs possessed effective cellular uptake and precise specific accumulation in tumor cells and tissues through CCM-targeted supramolecular in situ aggregation, demonstrating enhanced ferroptosis-inducing therapy of breast cancer. Overall, this work provided a supramolecular biomimetic platform to achieve targeted delivery of Fe3O4 NPs with high efficiency and precise self-assembly for improved cancer therapy.

The application of nanoparticles based on ferroptosis in cancer therapy

Ferroptosis is a new form of non-apoptotic programmed cell death. Due to its effectiveness in cancer treatment, there are increasing studies on the application of nanoparticles based on ferroptosis in cancer therapy. In this paper, we present a summary of the latest progress in nanoparticles based on ferroptosis for effective tumor therapy. We also describe the combined treatment of ferroptosis with other therapies, including chemotherapy, radiotherapy, phototherapy, immunotherapy, and gene therapy. This summary of drug delivery systems based on ferroptosis aims to provide a basis and inspire opinions for researchers concentrating on exploring this field. Finally, we present some prospects and challenges for the application of nanotherapies to clinical treatment by promoting ferroptosis in cancer cells.

New molecular insights into ferroptosis in lung adenocarcinoma progression and pharmacological compounds for targeted therapy

BACKGROUND

The involvement of ferroptosis has been found in many pathological conditions of the lung. The genetic engineering of ferroptosis-related genes may provide a potential target for the treatment of lung adenocarcinoma (LUAD).

METHODS

Nine ferroptosis regulators and markers were collected from FerrDb and their somatic mutations and expressions were analyzed based on The Cancer Genome Atlas (TCGA)-LUAD cohort data. Least absolute shrinkage and selection operator (LASSO) and Cox regression analysis were performed to screen genes significantly associated with ferroptosis. The ferroptosis-related gene signature was constructed using TCGA-LUAD cohort data and was verified using the GSE cohort with pooled data for GSE30219, GSE31210, GSE37745 and GSE50081. Immune microenvironment component and mutation analysis were performed for genes in the ferroptosis-related gene signature.

RESULTS

All nine ferroptosis regulators and markers were differentially expressed between normal LUAD tumor tissues and adjacent normal tissues and were related to copy number variation. The expression of 1329 genes were significantly associated with nine ferroptosis regulators and markers in the TCGA-LUAD dataset, five (ALDOA, PLK1, CD47, CENPC and TMOD3) of which were integrated into a ferroptosis-related gene signature to calculate the risk score of LUAD samples, showing a significant correlation with the abundance of immune cell infiltration and the immune score. Molecular docking showed the binding activity of natural active compound quercetin to target proteins ALDOA and CD47, as well as the binding activity of aristolochic acid to PLK1 protein and TMOD3 protein.

CONCLUSIONS

In the present study, a ferroptosis-related gene signature with predictive value for LUAD prognosis was constructed, in which the gene was a potential therapeutic target for LUAD. Quercetin and aristolochic acid were potential candidates for inhibiting these targets by directly binding to them and showing high affinity and strong stability.

Isoquercitrin promotes ferroptosis and oxidative stress in nasopharyngeal carcinoma via the AMPK/NF-κB pathway

Isoquercitrin has been discovered with various biological properties, including anticancer, anti-inflammation, antioxidation, and neuroprotection. The aim of this study is to explore the efficacy of isoquercitrin in nasopharyngeal carcinoma (NPC) and to disclose its potential regulating mechanisms. CNE1 and HNE1 cells were treated with various concentrations of isoquercitrin. Ferrostatin-1 (Fer-1, a ferroptosis inhibitor) and alpha-lipoic acid (ALA, an activator of the AMP-activated protein kinase [AMPK] pathway) treatments were conducted to verify the effects of isoquercitrin, respectively. Cell viability, proliferation, reactive oxygen species (ROS) generation, and lipid peroxidation were determined, respectively. GPX4 expression and ferroptosis- and pathway-related protein expression were measured. A xenograft tumor model was constructed by subcutaneously inoculating CNE1 cells into the middle groin of each mouse. We found that the IC50 values of CNE1 and HNE1 cells were 392.45 and 411.38 μM, respectively. CNE1 and HNE1 viability and proliferation were both markedly reduced with the increasing concentration of isoquercitrin. ROS generation and lipid peroxidation were both enhanced with declined ferroptosis-related markers under isoquercitrin treatment. The nuclear factor kappa B (NF-κB) pathway, the AMPK pathway, and the interleukin (IL)-1β expression were all markedly suppressed by isoquercitrin. Moreover, isoquercitrin restrained the tumor growth and enhanced lipid peroxidation and ferroptosis in vivo. Interestingly, both Fer-1 and ALA treatments distinctly offset isoquercitrin-induced effects in vitro and in vivo. These findings indicated that isoquercitrin might enhance oxidative stress and ferroptosis in NPC via AMPK/NF-κB p65 inhibition.

Enhancing anti-cancer potential by delivering synergistic drug combinations via phenylboronic acid modified PLGA nanoparticles through ferroptosis-based therapy

In this study, we investigated the potential of the sorafenib (SOR) and simvastatin (SIM) combination to induce ferroptosis-mediated cancer therapy. To enhance targeted drug delivery, we encapsulated the SOR + SIM combination within 4-carboxy phenylboronic acid (CPBA) modified PLGA nanoparticles (CPBA-PLGA(SOR + SIM)-NPs). The developed CPBA-PLGA(SOR + SIM)-NPs exhibited a spherical shape with a size of 213.1 ± 10.9 nm, a PDI of 0.22 ± 0.03, and a Z-potential of -22.9 ± 3.2 mV. Notably, these nanoparticles displayed faster drug release at acidic pH compared to physiological pH. In cellular experiments, CPBA-PLGA(SOR + SIM)-NPs demonstrated remarkable improvements, leading to a 2.51, 2.69, and 2.61-fold decrease in IC50 compared to SOR alone, and a 7.50, 16.71, and 5.11-fold decrease in IC50 compared to SIM alone in MDA-MB-231, A549, and HeLa cells, respectively. Furthermore, CPBA-PLGA(SOR + SIM)-NPs triggered a reduction in glutathione (GSH) levels, an increase in malondialdehyde (MDA) levels, and mitochondrial membrane depolarization in all three cell lines. Pharmacokinetic evaluation revealed a 2.50- and 2.63-fold increase in AUC0-∞, as well as a 1.53- and 2.46-fold increase in mean residence time (MRT) for SOR and SIM, respectively, compared to the free drug groups. Notably, the CPBA-PLGA(SOR + SIM)-NPs group exhibited significant reduction in tumor volume, approximately 9.17, 2.45, and 1.63-fold lower than the control, SOR + SIM, and PLGA(SOR + SIM)-NPs groups, respectively. Histological examination and biomarker analysis showed no significant differences compared to the control group, suggesting the biocompatibility of the developed particles for in-vivo applications. Altogether, our findings demonstrate that CPBA-PLGA(SOR + SIM)-NPs hold tremendous potential as an efficient drug delivery system for inducing ferroptosis, providing a promising therapeutic option for cancer treatment.

Emerging Role of Ferroptosis in Breast Cancer: Characteristics, Therapy, and Translational Implications for the Present and Future

Ferroptosis is a nonapoptotic, iron-dependent form of cell death that can be actuated in disease cells by expected improvements and manufactured specialists. Different studies have recently resurrected the role of this newly discovered cell death pathway and demonstrated its efficacy in treating breast cancer. Breast cancer is the most well-known type of cancer among women worldwide. Despite many years of research focusing on cell death in breast cancer, counting apoptosis, clinical treatment leftovers are difficult due to the high likelihood of recurrence. Ferroptosis is defined by a lack of lipid peroxide repair capacity by phospholipid hydroperoxides GPX4, accessibility of redox-active iron, and followed oxidation of polyunsaturated fatty acids acid-containing phospholipids signalling, amino acid and iron metabolism, ferritinophagy, epithelial-tomesenchymal transition, cell adhesion, and mevalonate and phospholipid biosynthesis can all be factors that influence ferroptosis susceptibility. Ferroptosis, an iron-dependent controlled cell death caused by excessive lipid peroxidation, has been entwined in breast cancer development and therapeutic response for the past decade. Advances in enhancing clinical drugs targeting ferroptosis are developing silver linings to treat breast cancer. Ferroptosis is influenced by metabolism and the expression of certain genes, making it a prospective therapeutic target for monitoring malignant growth and an appealing target for precision cancer medication disclosure. In the coming years, research into biomarkers to follow ferroptosis in patients with breast cancer and the course of events and the subsequent use of novel ferroptosis-based treatments will be captious. We present a fundamental analysis of the actual understanding of molecular mechanisms along with regulatory networks associated with ferroptosis, expected physiological functions in growth concealment, ferroptosis-associated differentially expressed genes, treatment targeting potential, and recent advances in the development of therapeutic strategies in this review.

The prognostic and antitumor roles of key genes of ferroptosis in liver hepatocellular cancer and stomach adenocarcinoma

BACKGROUND

Liver hepatocellular cancer (LIHC) and stomach adenocarcinoma (STAD) are common malignancies with high lethal ratios worldwide. Great progress has been achieved by using diverse therapeutic strategies; however, these diseases still have an unfavourable prognosis. Ferroptosis inducer drugs, unlike apoptosis-related drugs, can overcome the resistance to cancer therapy caused by traditional chemicals. However, the relationship between overall survival (OS) and ferroptosis-related genes, as well as the mechanisms involved, are largely unclear.

METHODS

The expression levels of AIFM2, GPX4, ACSL4, FTH1, NOS1, and PTGS2 in LIHC and STAD were obtained from UALCAN. The correlations of OS with these gene expression levels were obtained using the Kaplan-Meier Plotter database. The OS associated with genetic mutations of those genes compared to that of unchanged genes was analysed using the TIMER website. GO and KEGG enrichment analyses of ferroptosis-related genes and their coexpressed genes in LIHC and STAD were conducted using the STRING and DAVID databases. The relationship of PTGS2 and ACSL4 to immune cell infiltration was analysed using the TIMER website. The viability and GPX5 expression levels in LIHC cells treated with RSL3 and As2O3 were detected by MTT methods and western blotting, respectively.

RESULTS

Our results showed that GPX4, FTH1 and AIFM2 were overexpressed in LIHC and STAD. High levels of GPX4, FTH1 and AIFM2 were prominently correlated with better prognosis in LIHC. However, GPX and FTH1 in STAD did not show significant correlations with OS. AIFM2 in STAD had the opposite trend with OS compared with that in LIHC. Moreover, a high mutation rate of these genes (35.74%) was also observed in LIHC patients, and genetic mutation of these genes was correlated with shorter OS. In contrast, the genetic mutation of these genes did not change OS in STAD. Enrichment analysis showed that the respiratory electron transport chain, cell chemotaxis and T-cell migration were related to ferroptosis. ASCL4 and PTGS2 coexpressed with cytokines associated with immune cell infiltration. Compared to RSL3 or As2O3 alone, As2O3 plus RSL3 significantly inhibited the growth of Huh7 cells. GPX4 was downregulated to an undetectable level when in combination with RSL3.

CONCLUSIONS

Our results indicated that ferroptosis-related genes might play an important role in LIHC and STAD and might be risk factors for overall survival in LIHC and STAD.

Current evidence and therapeutic implication of PANoptosis in cancer

Regulated cell death (RCD) is considered a critical pathway in cancer therapy, contributing to eliminating cancer cells and influencing treatment outcomes. The application of RCD in cancer treatment is marked by its potential in targeted therapy and immunotherapy. As a type of RCD, PANoptosis has emerged as a unique form of programmed cell death (PCD) characterized by features of pyroptosis, apoptosis, and necroptosis but cannot be fully explained by any of these pathways alone. It is regulated by a multi-protein complex called the PANoptosome. As a relatively new concept first described in 2019, PANoptosis has been shown to play a role in many diseases, including cancer, infection, and inflammation. This study reviews the application of PCD in cancer, particularly the emergence and implication of PANoptosis in developing therapeutic strategies for cancer. Studies have shown that the characterization of PANoptosis patterns in cancer can predict survival and response to immunotherapy and chemotherapy, highlighting the potential for PANoptosis to be used as a therapeutic target in cancer treatment. It also plays a role in limiting the spread of cancer cells. PANoptosis allows for the elimination of cancer cells by multiple cell death pathways and has the potential to address various challenges in cancer treatment, including drug resistance and immune evasion. Moreover, active investigation of the mechanisms and potential therapeutic agents that can induce PANoptosis in cancer cells is likely to yield effective cancer treatments and improve patient outcomes. Research on PANoptosis is still ongoing, but it is a rapidly evolving field with the potential to lead to new treatments for various diseases, including cancer.

Synergistic anticancer therapy via ferroptosis using modified bovine serum albumin nanoparticles loaded with sorafenib and simvastatin

Ferroptosis is a non-apoptotic cell death pathway characterized by the accumulation of lipid-peroxy radicals within the affected cells. Here, we investigate the synergistic capacity of sorafenib (SOR) and simvastatin (SIM) to trigger ferroptosis for cancer therapy. For precise in-vivo delivery, SOR + SIM was ratiometrically loaded in bovine serum albumin nanoparticles (BSA-NPs) modified with 4-carboxy phenylboronic acid (CPBA). The developed CPBA-BSA(SOR + SIM)-NPs revealed size of 175.2 ± 12.8 nm, with PDI of 0.22 ± 0.03 and Z-potential of -29.6 ± 4.8 mV. Significantly, CPBA-BSA(SOR + SIM)-NPs exhibited > 2 and > 5-fold reduction in IC50 values compared to individual SOR and SIM treatments respectively, in all tested cell lines. Moreover, CPBA-BSA(SOR + SIM)-NPs treated cells exhibited decrease in glutathione levels, increase in malonaldehyde levels and depolarization of mitochondrial membrane potential (JC-1 assay). Pharmacokinetic analysis revealed enhanced AUC0-∞ and MRT levels for SOR and SIM when administered as CPBA-BSA(SOR + SIM)-NPs compared to free drugs. Crucially, in in-vivo experiments, CPBA-BSA(SOR + SIM)-NPs led to a significant reduction in tumor volume compared to various control groups. Histological and biomarker analyses underscore their biocompatibility for clinical applications. In conclusion, this study highlights the potential of CPBA-BSA(SOR + SIM)-NPs as a promising strategy for inducing ferroptosis in cancer cells, concurrently improving drug delivery and therapeutic efficacy. This approach opens new avenues in cancer treatment.

NFE2L1 restrains ferroptosis by transcriptionally regulating HJURP and participates in the progress of oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is a common head and neck malignancy with increasing mortality and high recurrence. In this work, we aim to explore the functional role of NFE2 like bZIP transcription factor 1 (NFE2L1) in OSCC progression. Based on databases analysis, we found that NFE2L1 was overexpressed in OSCC tumor tissues, and elevated NFE2L1 level induced poor prognosis of OSCC patients. Our results showed that NFE2L1 is upregulated in OSCC cells and overexpression of NFE2L1 promotes cell proliferation, and reduces the sensitivity of OSCC cells to erastin-induced ferroptosis. NFE2L1 upregulation decreased the levels of Fe2+, lipid reactive oxygen species and content of malondialdehyde, and increased the level of the key negative regulator of ferroptosis, GPX4 and SLC7A11. In NFE2L1 suppressed cells, these trends were reversed. Further results of dual luciferase reporter and chromatin immunoprecipitation assays confirmed that NFE2L1 could bind to the promoter of Holliday junction recognition protein (HJURP) to increase the transcriptional activity of HJURP, thus upregulating its expression. Inhibition of HJURP attenuated the proliferation and ferroptosis inhibition in NFE2L1 upregulated cells. In vivo tumorigenicity assay further proved that NFE2L1 promotes OSCC tumor growth. In summary, NFE2L1 restrains ferroptosis by transcriptionally regulating HJURP and participates in the progress of OSCC. Thus, NFE2L1 plays a key role in OSCC development and may be a promising therapeutic target for OSCC.

Effect and mechanism of paclitaxel loaded on magnetic Fe3O4@mSiO2-NH2-FA nanocomposites to MCF-7 cells

Magnetic Fe₃O₄ nanoparticles were prepared via a simple hydrothermal method and utilized to load paclitaxel. The average particle size of Fe₃O₄ nanoparticles was found to be 20.2 ± 3.0 nm, and the calculated saturation magnetization reached 129.38 emu/g, verifying superparamagnetism of nanomaterials. The specific surface area and pore volume were 84.756 m²/g and 0.265 cm³/g, respectively. Subsequently, Fe₃O₄@mSiO₂ nanoparticles were successfully fabricated using the Fe₃O₄ nanoparticles as precursors with an average size of 27.81 nm. The relevant saturation magnetization, zeta potential, and specific surface area of Fe₃O₄@mSiO₂-NH₂-FA were respectively 76.3 emu/g, -14.1 mV, and 324.410 m²/g. The pore volume and average adsorption pore size were 0.369 cm³/g and 4.548 nm, respectively. Compared to free paclitaxel, the solubility and stability of nanoparticles loaded with paclitaxel were improved. The drug loading efficiency and drug load of the nanoformulation were 44.26 and 11.38%, respectively. The Fe₃O₄@mSiO₂-NH₂-FA nanocomposites were easy to construct with excellent active targeting performance, pH sensitivity, and sustained-release effect. The nanoformulation also showed good biocompatibility, where the cell viability remained at 73.8% when the concentration reached 1200 μg/mL. The nanoformulation induced cell death through apoptosis, as confirmed by AO/EB staining and flow cytometry. Western blotting results suggested that the nanoformulation could induce iron death by inhibiting Glutathione Peroxidase 4 (GPX4) activity or decreasing Ferritin Heavy Chain 1 (FTH1) expression. Subsequently, the expression of HIF-1α was upregulated owing to the accumulation of reactive oxygen species (ROS), thus affecting the expression of apoptosis-related proteins regulated by p53, inducing cell apoptosis.

Battling colorectal cancer via s-triazine-based MMP-10/13 inhibitors armed with electrophilic warheads for concomitant ferroptosis induction; the first-in-class dual-acting agents

There is an increasing interest in halting CRC by combining ferroptosis with other forms of tumor cell death. However, ferroptosis induction is seldom studied in tandem with inhibiting MMPs. A combination that is expected to enhance the therapeutic outcome based on mechanistic ferroptosis studies highlighting the interplay with MMPs, especially MMP-13 associated with CRC metastasis and poor prognosis. Herein, we report new hybrid triazines capable of simultaneous MMP-10/13 inhibition and ferroptosis induction bridging the gap between their anticancer potentials. The MMP-10/13 inhibitory component of the scaffold was based on the non-hydroxamate model inhibitors. s-Triazine was rationalized as the core inspired by altretamine, an FDA-approved ferroptosis inducer. The ferroptosis pharmacophores were then installed as Michael acceptors via triazole-based spacers. The electrophilic reactivity was tuned by incorporating cyano and/or substituted phenyl groups influencing their electronic and steric properties and enriching the SAR study. Initial screening revealed the outstanding cytotoxicity profiles of the nitrophenyl-tethered chalcone 5e and the cyanoacrylohydrazides bearing p-fluorophenyl 9b and p-bromophenyl 9d appendages. 9b and 9d surpassed NNGH against MMP-10 and -13, especially 9d (IC50 = 0.16 μM). Ferroptosis studies proved that 9d depleted GSH in HCT-116 cells by a relative fold decrement of 0.81 with modest direct GPX4 inhibition, thus inducing lipid peroxidation, the hallmark of ferroptosis, by 1.32 relative fold increment. Docking presumed that 9d could bind to the MMP-10 S1' pocket and active site His221, extend through the MMP-13 hydrophobic pocket, and interact covalently with the GPX4 catalytic selenocysteine. 9d complexed with ferrous oxide nanoparticles was 7.5 folds more cytotoxic than its free precursor against HCT-116 cells. The complex-induced intracellular iron overload, depleted GSH with a relative fold decrement of 0.12, consequently triggering lipid peroxidation and ferroptosis by a 3.94 relative fold increment. Collectively, 9d could be a lead for tuning MMPs selectivity and ferroptosis induction potential to maximize the benefit of such a combination.

Machine learning- and WGCNA-mediated double analysis based on genes associated with disulfidptosis, cuproptosis and ferroptosis for the construction and validation of the prognostic model for breast cancer

BACKGROUND

Disulfidptosis, a recently discovered cellular death mechanism, has not been extensively studied in relation to breast cancer (BC). Specifically, no previous research has integrated disulfidptosis-related genes (DRGs), cuproptosis-related genes (CRGs), and ferroptosis-related genes (FRGs) to construct a prognostic signature for BC.

METHODS

DRGs, CRGs and FRGs with prognostic potential were identified through Cox regression analysis. A predictive model was constructed by intersecting the core genes obtained from unsupervised cluster analysis and weighted correlation network analysis (WGCNA). Differences in chemotherapy drug sensitivity, immune checkpoint levels were analyzed according to different risk score groups. The expression of the core disulfidptosis gene, SLC7A11, was analyzed using immunofluorescence.

RESULTS

Single-cell RNA sequencing analysis revealed differential expression of DRGs in the BC tumor microenvironment. We developed a prognostic model, consisting of six genes, based on machine learning which included unsupervised cluster analysis and Lasso-Cox analysis. An internal training set and a validation set, both derived from the Cancer Genome Atlas-Breast Cancer (TCGA-BRCA) database, GSE20685 and GSE42568 as external validation sets all verified the model's validity. The low-risk group exhibited increased sensitivity to paclitaxel. Additionally, the high-risk group demonstrated significantly higher expression of tumor mutation burden and microsatellite instability compared to the low-risk group. A nomogram confirmed that the risk score can be an independent risk factor for BC. Notably, our findings highlighted the impact of SLC7A11 on the BC tumor microenvironment. Immunofluorescence analysis revealed significantly higher expression of SLC7A11 in BC tissues compared to paracancerous tissues.

CONCLUSION

Multiplex analysis based on DRGs, CRGs and FRGs correlated strongly with BC, providing new insights for developing clinical prognostic tools and designing immunotherapy regimens for BC patients.

Curcumin induces ferroptosis and apoptosis in osteosarcoma cells by regulating Nrf2/GPX4 signaling pathway

Curcumin, an antitumor agent, has been shown to inhibit cell growth and metastasis in osteosarcoma. However, there is no evidence of curcumin and its regulation of cell ferroptosis and nuclear factor E2-related factor 2 (Nrf2)/glutathione peroxidase 4 (GPX4) signaling pathways in osteosarcoma. This study aimed to investigate the effects of curcumin on osteosarcoma both in vitro and in vivo. To explore the effects and mechanisms of curcumin on osteosarcoma, cells (MNNG/HOS and MG-63) and xenograft mice models were established. Cell viability, cell apoptosis rate, cycle distribution, cell migration, cell invasion, reactive oxygen species, malonaldehyde and glutathione abilities, and protein levels were detected by cell counting kit-8, flow cytometry, wound healing, transwell assay, respectively. Nrf2 and GPX4 expressions were detected using an immunofluorescence assay. Nrf2/GPX4-related protein levels were detected using western blotting. The results showed that curcumin effectively decreased cell viability and increased apoptosis rate. Meanwhile, curcumin inhibited tumor volume in the xenograft model, and Nrf2/GPX4-related protein levels were also altered. Interestingly, the effects of curcumin were reversed by liproxstatin-1 (an effective inhibitor of ferroptosis) and bardoxolone-methyl (an effective activator of Nrf2). Our results indicate that curcumin has therapeutic effects on osteosarcoma cells and a xenograft model by regulating the expression of the Nrf2/GPX4 signaling pathway.

TMEM44-AS1 promotes esophageal squamous cell carcinoma progression by regulating the IGF2BP2-GPX4 axis in modulating ferroptosis

The long non-coding RNA (lncRNA) TMEM44-AS1 is a novel lncRNA whose pro-carcinogenic role in gastric cancer and glioma has been demonstrated. However, its function in esophageal squamous cell carcinoma (ESCC) is unknown. In this study, we identified that TMEM44-AS1 was highly expressed in ESCC tissues and cells. Functionally, TMEM44-AS1 promoted ESCC cell proliferation, invasion and metastasis in vitro and in vivo. TMEM44-AS1 inhibited ferroptosis in ESCC cells, and ferroptosis levels were significantly increased after knockdown of TMEM44-AS1. Mechanistically, TMEM44-AS1 was positively correlated with GPX4 expression, and TMEM44-AS1 could bind to the RNA-binding protein IGF2BP2 to enhance the stability of GPX4 mRNA, thereby affecting ferroptosis and regulating the malignant progression of ESCC. In summary, this study reveals the TMEM44-AS1-IGF2BP2-GPX4 axis could influence cancer progression in ESCC. TMEM44-AS1 can be used as a potential treatment target against ESCC.

FTO Sensitizes Oral Squamous Cell Carcinoma to Ferroptosis via Suppressing ACSL3 and GPX4

Ferroptosis is a newly established form of regulated cell death characterized by intracellular lipid peroxidation and iron accumulation that may be a promising cancer treatment strategy. However, the function and therapeutic value of ferroptosis in oral squamous cell carcinoma (OSCC) remain inadequately understood. In the present study, we investigated the biological role of the fat mass and obesity-associated gene (FTO) in ferroptosis in the context of OSCC. We found that OSCC had greater potential for ferroptosis, and FTO is associated with ferroptosis. Furthermore, higher FTO expression sensitized OSCC cells to ferroptosis in vitro and in vivo. Mechanistically, FTO suppressed the expression of anti-ferroptotic factors, acyl-CoA synthetase long-chain family member 3 (ACSL3) and glutathione peroxidase 4 (GPX4), by demethylating the m6A modification on the mRNA of ACSL3 and GPX4 and decreasing their stability. Taken together, our findings revealed that FTO promotes ferroptosis through ACSL3 and GPX4 regulation. Thus, ferroptosis activation in OSCC with high FTO levels may serve as a potential therapeutic target.

Ferroptosis regulation by methylation in cancer

Epigenetic regulation plays a critical role in cancer development and progression. Methylation is an important epigenetic modification that influences gene expression by adding a methyl group to nucleic acids and proteins. Ferroptosis is a new form of regulated cell death triggered by the accumulation of iron and lipid peroxidation. Emerging evidence have shown that methylation regulation plays a significant role in the regulation of ferroptosis in cancer. This review aims to explore the methylation regulation of ferroptosis in cancer, including reactive oxygen species and iron bio-logical activity, amino acid and lipid metabolism, and drugs interaction. The findings of this review may provide new insights and strategies for the prevention and treatment of cancer.

Superoxide Dismutase-Like Regulated Fe/Ppa@PDA/B for Synergistically Targeting Ferroptosis/Apoptosis to Enhance Anti-Tumor Efficacy

The cell apoptosis pathway of sonodynamic therapy (SDT) is usually blocked, resulting in limited therapeutic efficacy, therefore, the development of new methods for sensitizing targeted ferroptosis and promoting apoptosis is of great significance to improve the anti-tumor efficacy of SDT. Herein, mesoporous Fe3 O4 nanoparticles (NPs) are synthesized for loading pyropheophorbide-a (ppa), surface-coated by polydopamine (PDA) and further anchored with tumor-targeting moieties of biotin to obtain Fe/ppa@PDA/B NPs. Fe/ppa@PDA/B displayes pH/ultrasound (US) responsive release properties, and magnetic resonance imaging (MRI) functions. Moreover, Fe3 O4 NPs of Fe/ppa@PDA/B as the Fe source for ferroptosis, enhances ferroptosis sensitivity by consuming glutathione (GSH) and producing hydroxyl radical (OH). The quinone groups of PDA layer on Fe/ppa@PDA/B own free electrons, which led to effective superoxide dismutase (SOD) action through superoxide anion (O2 - ) disproportionation to hydrogen peroxide (H2 O2 ) and oxygen (O2 ), thus, overcame hypoxia of SDT and promoted ·OH generation by Fe ions under US trigger, synergistically improves ferroptosis and apoptosis to enhance the anti-tumor efficacy of SDT both in vitro and in vivo. The anti-tumor strategy of synergistic apoptosis and ferroptosis induce by GSH depletion and self-sufficient O2 regulated by SOD provides a new idea for enhancing SDT efficacy.

Pan-Cancer Analysis and Experimental Validation of SOX4 as a Potential Diagnosis, Prognosis, and Immunotherapy Biomarker

INTRODUCTION

SOX4 plays an important role in tumorigenesis and cancer progression. The role of SOX4 in pan-cancer and its underlying molecular mechanism in liver hepatocellular carcinoma (LIHC) are not fully understood. In this study, a comprehensive analysis and experimental validation were performed to explore the function of SOX4 across tumor types.

METHODS

Raw data in regard to SOX4 expression in malignant tumors were downloaded from the TCGA and GTEx databases. The expression levels, prognostic values, genetic mutation, and DNA promoter methylation of SOX4 across tumor types were explored via systematic bioinformatics analysis. The ceRNA regulatory network, immune characteristics, and prognostic models were analyzed in LIHC. Finally, we conducted in vitro experiments including Western blotting, cell proliferative assay, trypan blue staining, and fluorescence microscopy to further explore the function of SOX4 in LIHC.

RESULTS

SOX4 expression was significantly upregulated in 24 tumor types. SOX4 expression level was strongly associated with unfavorable prognoses, genetic mutations, and DNA methylation levels across different tumor types. Especially in LIHC, LINC00152/hsa-miR-139-3p/SOX4 was identified as a crucial ceRNA network. Moreover, this study also provides insight into the roles of SOX4 expression in immune cell infiltration, macrophage polarization, immune subtype, molecular subtype, and immunomodulators, as well as the tumor immune microenvironment (TIME)-related prognosis, in LIHC. The study established six favorable prognostic models to predict LIHC prognosis based on the SOX4-associated genes. Finally, lenvatinib treatment can increase the expression of SOX4 in hepatocellular carcinoma cells and lead to drug resistance. Silencing SOX4 can effectively eliminate the drug resistance caused by lenvatinib treatment and inhibit the proliferation of cancer cells.

CONCLUSIONS

This study highlights that SOX4 may serve as a promising therapeutic target for tumor treatment.

Natural product piperlongumine inhibits proliferation of oral squamous carcinoma cells by inducing ferroptosis and inhibiting intracellular antioxidant capacity

Background

As a new form of cell death, ferroptosis has been shown to have inhibitory effects on a variety of tumor cells except oral squamous cell carcinoma (OSCC). There were few investigations on the effects and molecular mechanisms of piperlongumine (PL, a ferroptosis inducer) and CB-839 (a GLS1 inhibitor which promotes ferroptosis) on OSCC cells. This article assesses the anticancer effect and mechanism of PL as well as combined with CB-839.

Methods

OSCC cells were treated with specified concentration of PL alone or with ferroptosis inhibitor Ferrostatin-1 (Fer-1) and antioxidant N-Acetylcysteine (NAC) to assess their effects on biological characteristics such as cell proliferation, cell death and intracellular ferroptosis related pathways. Also, cells were treated with PL combined with CB-839 to evaluate the synergistic effect of CB-839 on PL's anticancer effects.

Results

The results showed that the proliferation rate of PL-treated OSCC cells were decreased in a dose- and time-dependent manner. PL can induce OSCC cells apoptosis. Lipid peroxidation (LPO) and intracellular reactive oxygen species (ROS) were accumulated after PL treatment. We found some protein changes significantly such as the expression of DMT1 increased, and the expression of FTH1, SLC7A11 and GPX4 decreased. In addition, the anti-proliferation effect of PL can be reversed by Fer-1 and NAC and the level of LPO and ROS was decreased accordingly. Importantly, we found that PL and CB-839 in combination could decrease the cell viability and the LPO level synergistically, accompanied by a large consumption of glutathione (GSH). These evidences prove that PL can induce ferroptosis of OSCC cells, which can be enhanced by CB-839.

Conclusions

Our study suggested that the nature product PL can induce the ferroptotic death of OSCC cells, which is further enhanced when combined with CB-839. The synergistic anticancer effect of these two may prove new strategy for OSCC treatment.

Application of singlet oxygen-activatable nanocarriers to boost X-ray-induced photodynamic therapy and cascaded ferroptosis for breast cancer treatment

Ferroptosis has appealing antitumor potential that is mainly based on the accumulation of lipid peroxide to a lethal level. The cytotoxic singlet oxygen (1O2) generated from nanoscale X-ray-induced photodynamic therapy (X-PDT) may facilitate glutathione (GSH) depletion and further activate ferroptosis. To realize combined X-PDT and ferroptosis, a nanocarrier (D-NPVR) was engineered with a hyperbranched copolymer with 1O2-sensitive linkers, where both the photosensitizer (verteporfin) and ferroptosis inducer RAS-selective lethal small molecule 3 (RSL3) were encapsulated. Upon X-ray radiation, D-NPVR could produce a large amount of 1O2 for apoptosis. Subsequently, 1O2 triggered D-NP dissociation by cleavage of 1,2-bis(2-hydroxyethylthio)ethylene bonds to boost payload release and decrease levels of intracellular GSH via thiol oxidation. Liberated RSL3 is a covalent inhibitor for glutathione peroxide 4 (GPX4), which is responsible for detoxifying lipid peroxides to lipid alcohols with GSH assistance, and both 1O2-induced GSH depletion and GPX4 inactivation thereby produced ferroptotic cell death. Tumor growth inhibition in murine 4T1 tumor-bearing mice demonstrated that D-NPVR produced pronounced therapeutic efficiency where ferroptosis induction was supported by the GPX4 content and expression. This study highlights the contribution of 1O2-sensitive nanocarriers for promoting the potency of combined X-PDT and ferroptosis.

FANCD2 as a novel prognostic biomarker correlated with immune and drug therapy in Hepatitis B-related hepatocellular carcinoma

BACKGROUND

Ferroptosis is related to the immunosuppression of tumors and plays a critical role in cancer progression. Fanconi anemia complementation group D2 (FANCD2) is a vital gene that regulates ferroptosis. However, the mechanism of action of FANCD2 in Hepatitis B-related hepatocellular carcinoma (HCC) remains unknown. In this study, we investigated the prognostic significance and mechanism of action of FANCD2 in Hepatitis B-related HCC.

METHODS

The expression of FANCD2 in Hepatitis B-related HCC was explored using The Cancer Genome Atlas (TCGA) and validated using the Gene Expression Omnibus (GEO) database. Univariate and multivariate Cox regression analyses and Kaplan-Meier survival curves were used to analyze the relationship between FANCD2 expression and the overall survival of patients with Hepatitis B-related HCC. Protein-protein interaction networks for FANCD2 were built using the STRING website. In addition, correlations between FANCD2 expression and the dryness index, tumor mutational burden, microsatellite instability (MSI), immune pathways, genes involved in iron metabolism, and sorafenib chemotherapeutic response were analyzed.

RESULTS

Our results indicated that FANCD2 was significantly overexpressed in Hepatitis B-related HCC and demonstrated a strong predictive ability for diagnosis (Area Under Curve, 0.903) and prognosis of the disease. High FANCD2 expression was associated with poor prognosis, high-grade tumors, high expression of PDL-1, high MSI scores, and low sorafenib IC50 in Hepatitis B-related HCC. BRCA1, BRCA2, FAN1, and FANCC were vital proteins interacting with FANCD2. The expression level of FANCD2 significantly correlated with the infiltration levels of Treg cells, B cells, CD8 + T cells, CD4 + T cells, neutrophils, macrophages, myeloid dendritic cells, and NK cells in Hepatitis B-related HCC. FANCD2 was positively correlated with the tumor proliferation signature pathway, DNA repair, and cellular response to hypoxia.

CONCLUSION

Our study indicated that FANCD2 was a potential novel biomarker and immunotherapeutic target against Hepatitis B-related HCC, which might be related to the chemotherapeutic response to sorafenib.

Enhanced efficacy of combined fluzoparib and chidamide targeting in natural killer/T-cell lymphoma

The treatment of natural killer/T-cell lymphoma (NKTCL) presents an onerous challenge, and a search for new therapeutic targets is urgently needed. Poly ADP-ribose polymerase inhibitors (PARPi) were initially used to treat breast and ovarian cancers with BRCA1/2 mutations. Their excellent antitumor efficacy led to a series of clinical trials conducted in other malignancies. However, the exploration of PARPi and their potential use in combination treatments for NKTCL remains unexplored. We treated NKTCL cell lines with fluzoparib (a novel inhibitor of PARP) and chidamide (a classical inhibitor of HDACs) to explore their cytotoxic effects in vitro. Then, their antitumor efficacy in vivo was confirmed in YT-luciferin xenograft mouse models. Fluzoparib or chidamide alone inhibited NKTCL cell proliferation in a dose-dependent manner. Cotreatment with both drugs synergistically induced excessive accumulation of DNA double-strand breaks and massive apoptotic cell death by inhibiting the DNA damage repair pathway, as shown by the decreased protein levels of p-ATM, p-BRCA1, p-ATR, and Rad51. Moreover, the combination treatment apparently increased the level of intracellular reactive oxygen species (ROS) to enhance apoptosis, and pretreatment with an ROS scavenger reduced the proapoptotic effect by 30-60% in NKTCL cell lines. In vivo, this combined regimen also showed synergistic antitumor effects in xenograft mouse models. The combination of fluzoparib and chidamide showed synergistic effects against NKTCL both in vitro and in vivo and deserves further exploration in clinical trials.

Dihydroorotate dehydrogenase promotes cell proliferation and suppresses cell death in esophageal squamous cell carcinoma and colorectal carcinoma

Background

Ferroptosis is defined as an iron-dependent non-apoptotic form of programmed cell death. Dihydroorotate dehydrogenase (DHODH) is a newly discovered anti-ferroptosis molecule independent from the well-known GPX4 and AIFM2. However, the expression pattern and especially the functional roles of DHODH during cancer cell death are generally unknown.

Methods

The databases of Gene Expression Profiling Interactive Analysis (GEPIA), Kaplan-Meier Plotter, and Tumor Immune Estimation Resource (TIMER), and methods of colony formation, Cell Counting Kit-8 (CCK-8), adenosine triphosphate (ATP) detection, RNA-seq, quantitative reverse transcription polymerase chain reaction (qRT-PCR), and western blotting were used to analyze the expression level, prognostic role, and oncogenic roles of DHODH in cancers.

Results

DHODH overexpression was identified in many types of cancers including esophageal carcinoma (ESCA), colon adenocarcinoma (COAD), rectum adenocarcinoma (READ), and so on. Silence and inactivation of DHODH decreased the abilities of cell proliferation, colony formation, and cellular ATP levels both in esophageal squamous cell carcinoma (ESCC) and colorectal cancer (CRC) cells. Z-VAD-FMK (an apoptosis inhibitor) partially rescued blockade of DHODH-induced death of ESCC cells, and ferroptosis inhibitors (ferrostatin-1 and liproxstatin-1) together with the necroptosis inhibitor (necrostatin-1) partially rescued inhibition of DHODH-induced death of CRC cells, respectively. Pathways including rheumatoid arthritis, salmonella infection, cytokine-cytokine receptor interaction, pertussis, and nuclear factor-κB (NF-κB) were enriched in DHODH-silenced ESCC cells.

Conclusions

Overexpression of DHODH augments cell proliferation and suppresses cell death in ESCC and CRC, and DHODH might be developed as a potential anticancer target.

Acetylcholine receptor agonists effectively attenuated multiple program cell death pathways and improved left ventricular function in trastuzumab-induced cardiotoxicity in rats

AIMS

Cardiotoxicity is a seriously debilitating complication of trastuzumab (TRZ) therapy in patients with cancer as a consequence of overexpression of the human epidermal growth factor receptor 2. Although most TRZ-induced cardiotoxicity (TIC) cases are reversible, some patients experience chronic cardiac dysfunction, and these irreversible concepts may be associated with cardiomyocyte death. Acetylcholine receptor (AChR) activation has been shown to exert cardioprotection in several heart diseases, but the effects of AChR agonists against TIC have not been investigated.

MAIN METHOD

Forty adult male Wistar rats were randomized into 5 groups: (i) CON (0.9 % normal saline), (ii) TRZ (4 mg/kg/day), (iii) TRZ + α7nAChR agonist (PNU-282987: 3 mg/kg/day), (iv) TRZ + mAChR agonists (bethanechol: 12 mg/kg/day), and (v) TRZ + combined treatment (Combined PNU-282987 and bethanechol).

KEY FINDINGS

The progression of TIC was driven by mitochondrial dysfunction, autophagic deficiency, and excessive myocyte death including by pyroptosis, ferroptosis, and apoptosis, which were significantly alleviated by α7nAChR and mAChR agonists. Interestingly, necroptosis was not associated with development of TIC. More importantly, the in vitro study validated the cytoprotective effects of AChR activation in TRZ-treated H9c2 cells, while not interfering with the anticancer properties of TRZ. All of these findings indicated that TRZ induced mitochondrial dysfunction, autophagic deficiency, and excessive myocyte death including pyroptosis, ferroptosis, and apoptosis, leading to impaired cardiac function. These pathological alterations were attenuated by α7nAChR and mAChR agonists.

SIGNIFICANCE

α7nAChR and mAChR agonists might be used as a future therapeutic target in the mitigation of TIC.

Exploring Sorafenib and Simvastatin Combination for Ferroptosis-Induced Cancer Treatment: Cytotoxicity Screening, In Vivo Efficacy, and Safety Assessment

Ferroptosis, a pathway dependent on oxygen and iron catalysts, holds promise as a therapeutic approach for cancer treatment due to its manageable regulation, direct control, and immunogenic properties. The sensitivity of cancer cells to ferroptosis induction varies based on their metabolic, genetic, and signalling pathways, prompting the use of combination therapy. In this study, we conducted a screening of drug combinations, including sorafenib (SOR) with simvastatin (SIM), phenethyl isothiocyanate, and trigonelline, in MDA-MB-231, A549, and HeLa cells to assess their cytotoxicity. The SOR-SIM combination exhibited a synergistic effect in MDA-MB-231, A549, and HeLa cells, with calculated CI values of ~ 0.66, 0.53, and 0.59, respectively. Furthermore, co-treatment with ferrostatin-1 resulted in a concentration-dependent increase in the IC50 values. Additionally, SOR + SIM demonstrated a significant reduction in GSH levels, an increase in MDA levels, and mitochondrial membrane depolarization across all three cell lines, indicating their ferroptosis inducing potential. In-vivo studies showed a significant reduction in tumor volume by 3.53-, 2.55-, and 1.47-fold compared to control, SIM, and SOR, respectively. Toxicity assessments revealed insignificant changes in biomarker levels and no observable deformations in isolated organs, except for erythrocyte shrinkage and membrane scrambling effects caused by the SOR + SIM combination. Overall, our findings highlight the potential of the SOR + SIM combination as an effective strategy for cancer treatment, emphasizing the importance of further research in targeted drug delivery systems to ensure its safety.

NRF2, a Superstar of Ferroptosis

Ferroptosis is an iron-dependent and lipid peroxidation-driven cell death cascade, occurring when there is an imbalance of redox homeostasis in the cell. Nuclear factor erythroid 2-related factor 2 (NFE2L2, also known as NRF2) is key for cellular antioxidant responses, which promotes downstream genes transcription by binding to their antioxidant response elements (AREs). Numerous studies suggest that NRF2 assumes an extremely important role in the regulation of ferroptosis, for its various functions in iron, lipid, and amino acid metabolism, and so on. Many pathological states are relevant to ferroptosis. Abnormal suppression of ferroptosis is found in many cases of cancer, promoting their progression and metastasis. While during tissue damages, ferroptosis is recurrently promoted, resulting in a large number of cell deaths and even dysfunctions of the corresponding organs. Therefore, targeting NRF2-related signaling pathways, to induce or inhibit ferroptosis, has become a great potential therapy for combating cancers, as well as preventing neurodegenerative and ischemic diseases. In this review, a brief overview of the research process of ferroptosis over the past decade will be presented. In particular, the mechanisms of ferroptosis and a focus on the regulation of ferroptosis by NRF2 will be discussed. Finally, the review will briefly list some clinical applications of targeting the NRF2 signaling pathway in the treatment of diseases.

A bibliometric study and visualization analysis of ferroptosis-inducing cancer therapy

Ferroptosis is a form of regulated cell death that was first formally proposed a decade ago. While its role in cancer cell death was initially understudied, it has recently gained considerable interest from researchers. In recent years, a growing number of studies have focused on the role of ferroptosis in cancer progression, with the goal of developing novel ferroptosis-inducing cancer therapies. This study aims to present the developmental trend and hotspots of research on ferroptosis-inducing cancer therapy using bibliometric analysis. A literature search was conducted using the Web of Science Core Collection on October 1st, 2022, to retrieve articles and reviews pertaining to ferroptosis and cancer published from 2012 to 2022. Microsoft Excel 2016, VOSviewer 1.6.18 and CiteSpace (version 6.1. R6) were utilized to conduct the bibliometric analysis of publication trends, authorship, and citation networks, with a focus on identifying countries, institutions, journals, and authors contributing to the field. These analyses were used to predict future trends in this area. A total of 2839 articles were identified and extracted for analysis. The number of publications has increased almost every year, with a sharp increase after 2018. China produced the most publications in this area, followed by the United States. Central South University was the institution that published the most papers. Frontiers in Oncology was the journal with the highest number of publications, while Cell had the greatest impact factor. Daolin Tang was the most productive author and Dixon SJ was the most influential author. Co-occurrence and burst analyses of keywords and references were conducted to identify the developmental trends and hotspots in ferroptosis-inducing cancer therapy research. Main research directions have shifted from investigating the mechanism of ferroptosis to developing novel ferroptosis-targeting cancer therapies. Emerging topicsfocus on the role of ferroptosis in solid tumor therapy. Based on our bibliometric analysis, we predict that research on ferroptosis in cancer therapy will continue to be a hot topic in the future, with a growing number of treatment modalities related to ferroptosis being developed. Our study provides valuable insights into the current state and future trends of research in this field, serving as a useful guide for researchers seeking to make important contributions in this area.

Marine Alkaloid Lepadins E and H Induce Ferroptosis for Cancer Chemotherapy

Induction of ferroptosis emerges as an effective method for cancer treatment. With massive efforts to elucidate the ferroptosis mechanism, the development of new ferroptosis inducers proceeds rather slowly, with only a few small molecules identified. Herein, we report our discovery of marine alkaloid lepadins E and H as a new class of ferroptosis inducers. Our in vitro studies show that lepadins E and H exhibit significant cytotoxicity, promote p53 expression, increase ROS production and lipid peroxides, reduce SLC7A11 and GPX4 levels, and upregulate ACSL4 expression, all of which consistently support induction of ferroptosis through the classical p53-SLC7A11-GPX4 pathway. Our animal model study of lepadin H confirms its in vivo antitumor efficacy with negligible toxicity to normal organs. This work elucidates the mode of action of lepadins (E and H) and verifies their in vivo efficacy as a new class of ferroptosis inducers for anticancer therapy with translational potential.

Ferroptosis and EMT: key targets for combating cancer progression and therapy resistance

Iron-dependent lipid peroxidation causes ferroptosis, a form of regulated cell death. Crucial steps in the formation of ferroptosis include the accumulation of ferrous ions (Fe2+) and lipid peroxidation, of which are controlled by glutathione peroxidase 4 (GPX4). Its crucial role in stopping the spread of cancer has been shown by numerous studies undertaken in the last ten years. Epithelial-mesenchymal transition (EMT) is the process by which epithelial cells acquire mesenchymal characteristics. EMT is connected to carcinogenesis, invasiveness, metastasis, and therapeutic resistance in cancer. It is controlled by a range of internal and external signals and changes the phenotype from epithelial to mesenchymal like. Studies have shown that mesenchymal cancer cells tend to be more ferroptotic than their epithelial counterparts. Drug-resistant cancer cells are more easily killed by inducers of ferroptosis when they undergo EMT. Therefore, understanding the interaction between ferroptosis and EMT will help identify novel cancer treatment targets. In-depth discussion is given to the regulation of ferroptosis, the potential application of EMT in the treatment of cancer, and the relationships between ferroptosis, EMT, and signaling pathways associated with tumors. Invasion, metastasis, and inflammation in cancer all include ferroptosis and EMT. The goal of this review is to provide suggestions for future research and practical guidance for applying ferroptosis and EMT in clinical practice.

The ubiquitin-specific protease 5 mediated deubiquitination of LSH links metabolic regulation of ferroptosis to hepatocellular carcinoma progression

Epigenetic regulators and posttranslational modifications of proteins play important roles in various kinds of cancer cell death, including ferroptosis, a non-apoptotic form of cell death. However, the interplay of chromatin modifiers and deubiquitinase (DUB) in ferroptosis remains unclear. Here, we found that ubiquitin-specific protease 5 (USP5) is regarded as a bona fide DUB of lymphoid-specific helicase (LSH), a DNA methylation repressor, in hepatocellular carcinoma (HCC). Functional studies reveal that USP5 interacts with LSH and stabilizes LSH by a deubiquitylation activity-dependent process. Furthermore, the USP5-mediated deubiquitination of LSH facilitates the tumorigenesis of HCC by upregulating solute carrier family 7 member 11 (SLC7A11) to suppress ferroptosis of liver cancer cells. Moreover, the USP5 inhibitor degrasyn inhibits DUB activities of USP5 to LSH to suppress the progression of HCC. Additionally, USP5 and LSH are positively correlated and both are overexpressed and linked to poor prognosis in HCC patients. Together, our findings show that USP5 interacts with LSH directly and enhances LSH protein stability through deubiquitination, which, in turn, promotes the development of HCC by suppressing ferroptosis of liver cancer cells, suggesting that USP5 may be a potential therapeutic target for HCC.

Aspirin triggers ferroptosis in hepatocellular carcinoma cells through restricting NF-κB p65-activated SLC7A11 transcription

A number of studies have shown that aspirin, as commonly prescribed drug, prevents the development of hepatocellular carcinoma (HCC). Ferroptosis as a dynamic tumor suppressor plays a vital role in hepatocarcinogenesis. In this study we investigated whether aspirin affected ferroptosis in liver cancer cells. RNA-seq analysis revealed that aspirin up-regulated 4 ferroptosis-related drivers and down-regulated 5 ferroptosis-related suppressors in aspirin-treated HepG2 cells. Treatment with aspirin (4 mM) induced remarkable ferroptosis in HepG2 and Huh7 cells, which was enhanced by the ferroptosis inducer erastin (10 μM). We demonstrated that NF-κB p65 restricted ferroptosis in HepG2 and Huh7 cells through directly binding to the core region of SLC7A11 promoter and activating the transcription of ferroptosis inhibitor SLC7A11, whereas aspirin induced ferroptosis through inhibiting NF-κB p65-activated SLC7A11 transcription. Overexpression of p65 rescued HepG2 and Huh7 cells from aspirin-induced ferroptosis. HCC patients with high expression levels of SLC7A11 and p65 presented lower survival rate. Functionally, NF-κB p65 blocked the aspirin-induced ferroptosis in vitro and in vivo, which was attenuated by erastin. We conclude that aspirin triggers ferroptosis by restricting NF-κB-activated SLC7A11 transcription to suppress the growth of HCC. These results provide a new insight into the mechanism by which aspirin regulates ferroptosis in hepatocarcinogenesis. A combination of aspirin and ferroptosis inducer may provide a potential strategy for the treatment of HCC in clinic.

Bioactive peptides derived from Radix Angelicae sinensis inhibit ferroptosis in HT22 cells through direct Keap1-Nrf2 PPI inhibition

The development of natural peptides as direct Kelch-like ECH-associated protein 1 (Keap1)-nuclear factor erythroid2-related factor 2 (Nrf2) protein-protein interaction (PPI) inhibitors for antioxidant and anti-ferroptotic purposes has attracted increasing interest from chemists. Radix Angelicae sinensis (RAS) is a widely used traditional Chinese medicine with antioxidant capability. However, few studies have screened Keap1-Nrf2 PPI inhibitory RAS peptides (RASPs). This study optimized the extraction and hydrolysis protocols of RAS protein using response surface methodology coupled with Box-Behnken design. The molecular weight distribution of the prepared hydrolysates was analysed to obtain active fractions. Subsequently, ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry was employed to identify RASPs. Various in vitro and in silico assays were conducted to evaluate the antioxidant and anti-ferroptotic effects of RASPs. The results revealed that at least 50 RASPs could be obtained through the optimized protocols. RASPs containing active residues effectively scavenged 2,2-diphenyl-1-picrylhydrazyl radical and 2,2'-azinobis(3-ethylbenzothiazoline)-6-sulfonic acid radical cation. They also showed cytoprotective effect against erastin-induced ferroptosis in HT22 cells, which was characterized by the activation of Nrf2 and weakened under the incubation of an Nrf2 inhibitor. Moreover, RASPs could bind to Keap1 and then dissociate Nrf2 in molecular dynamics simulations. In conclusion, RASPs exhibit antioxidant activity through hydrogen atom transfer and electron transfer mechanisms. Importantly, they also inhibit ferroptosis by directly inhibiting Keap1-Nrf2 PPI.

Discovery of Novel Potent Covalent Glutathione Peroxidase 4 Inhibitors as Highly Selective Ferroptosis Inducers for the Treatment of Triple-Negative Breast Cancer

Glutathione peroxidase 4 (GPX4) is a promising target to induce ferroptosis for the treatment of triple-negative breast cancer (TNBC). We designed and synthesized a novel series of covalent GPX4 inhibitors based on RSL3 and ML162 by structural integration and simplification strategies. Among them, compound C18 revealed a remarkable inhibitory activity against TNBC cells and significantly inhibited the activity of GPX4 compared to RSL3 and ML162. Moreover, it was identified that C18 could notably induce ferroptosis with high selectivity by increasing the accumulation of lipid peroxides (LPOs) in cells. Further study demonstrated that C18 covalently bound to the Sec46 of GPX4. Surprisingly, C18 exhibited an outstanding potency of tumor growth inhibition in the MDA-MB-231 xenograft model with a TGI value of 81.0%@20 mg/kg without obvious toxicity. Overall, C18 could be a promising GPX4 covalent inhibitor to induce ferroptosis for the treatment of TNBC.

Cuproptosis/ferroptosis-related gene signature is correlated with immune infiltration and predict the prognosis for patients with breast cancer

Background: Breast invasive carcinoma (BRCA) is a malignant tumor with high morbidity and mortality, and the prognosis is still unsatisfactory. Both ferroptosis and cuproptosis are apoptosis-independent cell deaths caused by the imbalance of corresponding metal components in cells and can affect the proliferation rate of cancer cells. The aim in this study was to develop a prognostic model of cuproptosis/ferroptosis-related genes (CFRGs) to predict survival in BRCA patients. Methods: Transcriptomic and clinical data for breast cancer patients were obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Cuproptosis and ferroptosis scores were determined for the BRCA samples from the TCGA cohort using Gene Set Variation Analysis (GSVA), followed by weighted gene coexpression network analysis (WGCNA) to screen out the CFRGs. The intersection of the differentially expressed genes grouped by high and low was determined using X-tile. Univariate Cox regression and least absolute shrinkage and selection operator (LASSO) were used in the TGCA cohort to identify the CFRG-related signature. In addition, the relationship between risk scores and immune infiltration levels was investigated using various algorithms, and model genes were analyzed in terms of single-cell sequencing. Finally, the expression of the signature genes was validated with quantitative real-time PCR (qRT‒PCR) and immunohistochemistry (IHC). Results: A total of 5 CFRGs (ANKRD52, HOXC10, KNOP1, SGPP1, TRIM45) were identified and were used to construct proportional hazards regression models. The high-risk groups in the training and validation sets had significantly worse survival rates. Tumor mutational burden (TMB) was positively correlated with the risk score. Conversely, Tumor Immune Dysfunction and Exclusion (TIDE) and tumor purity were inversely associated with risk scores. In addition, the infiltration degree of antitumor immune cells and the expression of immune checkpoints were lower in the high-risk group. In addition, risk scores and mTOR, Hif-1, ErbB, MAPK, PI3K/AKT, TGF-β and other pathway signals were correlated with progression. Conclusion: We can accurately predict the survival of patients through the constructed CFRG-related prognostic model. In addition, we can also predict patient immunotherapy and immune cell infiltration.

Galectin-1-mediated MET/AXL signaling enhances sorafenib resistance in hepatocellular carcinoma by escaping ferroptosis

Sorafenib, a small-molecule inhibitor targeting several tyrosine kinase pathways, is the standard treatment for advanced hepatocellular carcinoma (HCC). However, not all patients with HCC respond well to sorafenib, and 30% of patients develop resistance to sorafenib after short-term treatment. Galectin-1 modulates cell-cell and cell-matrix interactions and plays a crucial role in HCC progression. However, whether Galectin-1 regulates receptor tyrosine kinases by sensitizing HCC to sorafenib remains unclear. Herein, we established a sorafenib-resistant HCC cell line (Huh-7/SR) and determined that Galectin-1 expression was significantly higher in Huh-7/SR cells than in parent cells. Galectin-1 knockdown reduced sorafenib resistance in Huh-7/SR cells, whereas Galectin-1 overexpression in Huh-7 cells increased sorafenib resistance. Galectin-1 regulated ferroptosis by inhibiting excessive lipid peroxidation, protecting sorafenib-resistant HCC cells from sorafenib-mediated ferroptosis. Galectin-1 expression was positively correlated with poor prognostic outcomes for HCC patients. Galectin-1 overexpression promoted the phosphorylation of AXL receptor tyrosine kinase (AXL) and MET proto-oncogene, receptor tyrosine kinase (MET) signaling, which increased sorafenib resistance. MET and AXL were highly expressed in patients with HCC, and AXL expression was positively correlated with Galectin-1 expression. These findings indicate that Galectin-1 regulates sorafenib resistance in HCC cells through AXL and MET signaling. Consequently, Galectin-1 is a promising therapeutic target for reducing sorafenib resistance and sorafenib-mediated ferroptosis in patients with HCC.

Micronutrients/miRs/ATP networking in mitochondria: Clinical intervention with ferroptosis, cuproptosis, and calcium burden

The mitochondrial electron transport chain (mtETC) requires mainly coenzyme Q10 (CoQ10), copper (Cu2+), calcium (Ca2+), and iron (Fe2+) ions for efficient ATP production. According to cross-sectional research, up to 50% of patients with micronutrient imbalances have been linked to oxidative stress, mitochondrial dysfunction, reduced ATP production, and the prognosis of various diseases. The condition of ferroptosis, which is caused by the downregulation of CoQ10 and the activation of non-coding micro RNAs (miRs), is strongly linked to free radical accumulation, cancer, and neurodegenerative diseases. The entry of micronutrients into the mitochondrial matrix depends upon the higher threshold level of mitochondrial membrane potential (ΔΨm), and high cytosolic micronutrients. The elevated micronutrient in the mitochondrial matrix causes the utilization of all ATP, leading to a drop in ATP levels. Mitochondrial calcium uniporter (MCU) and Na+/Ca2+ exchanger (NCX) play a major role in Ca2+ influx in the mitochondrial matrix. The mitochondrial Ca2+ overload is regulated by specific miRs such as miR1, miR7, miR25, miR145, miR138, and miR214, thereby reducing apoptosis and improving ATP production. Cuproptosis is primarily brought on by increased Cu+ build-up and mitochondrial proteotoxic stress, mediated by ferredoxin-1 (FDX1) and long non-coding RNAs. Cu importers (SLC31A1) and exporters (ATP7B) influence intracellular Cu2+ levels to control cuproptosis. According to literature reviews, very few randomized micronutrient interventions have been carried out, despite the identification of a high prevalence of micronutrient deficiencies. In this review, we concentrated on essential micronutrients and specific miRs associated with ATP production that balance oxidative stress in mitochondria.

A novel water-soluble Cu(II) gluconate complex inhibits cancer cell growth by triggering apoptosis and ferroptosis related mechanisms

Metal copper complexes have attracted extensive attention as potential alternatives to platinum-based anticancer drugs due to their possible different modes of action. Herein, a new copper(II) gluconate complex, namely [Cu(DPQ)(Gluc)]·2H₂O (CuGluc, DPQ = pyrazino[2,3-f][1,10]phenanthroline), with good water-solubility and high anticancer activity was synthesized by using D-gluconic acid (Gluc-2H) as an auxiliary ligand. The complex was well characterized by single-crystal X-ray diffraction analysis, elemental analysis, molar conductivity, and Fourier transform infrared spectroscopy (FTIR). The DNA-binding experiments revealed that CuGluc was bound to DNA by intercalation with end-stacking binding. CuGluc could oxidatively cleave DNA, in which ¹O₂ and H₂O₂ were involved. In addition, CuGluc was bound to the IIA subdomain of human serum albumin (HSA) through hydrophobic interaction and hydrogen bonding, showing a good affinity for HSA. The complex showed superior anticancer activity toward several cancer cells than cisplatin in vitro. Further studies indicated that CuGluc caused apoptotic cell death in human liver cancer (HepG2) cells through elevated intracellular reactive oxygen species (ROS) levels, mitochondrial dysfunction, cell cycle arrest, and caspase activation. Interestingly, CuGluc also triggered the ferroptosis mechanism through lipid peroxide accumulation and inhibition of glutathione peroxidase 4 (GPX4) activity. More importantly, CuGluc significantly inhibited tumor growth in vivo, which may benefit from the combined effects of apoptosis and ferroptosis. This work provides a promising strategy to develop highly effective antitumor copper complexes by coordinating with the glucose metabolite D-gluconic acid and exploiting the synergistic effects of apoptosis and ferroptosis mechanisms.

Ferroptosis: From regulation of lipid peroxidation to the treatment of diseases

Ferroptosis is a regulated cell death mainly manifested by iron-dependent lipid peroxide accumulation. The leading cause of ferroptosis is the imbalance of intracellular oxidative systems (e.g., LOXs, POR, ROS) and antioxidant systems (e.g., GSH/GPx4, CoQ10/FSP1, BH4/GCH1), which is regulated by a complex network. In the past decade, this metabolic network has been continuously refined, and the links with various pathophysiological processes have been gradually established. Apoptosis has been regarded as the only form of regulated cell death for a long time, and the application of chemotherapeutic drugs to induce apoptosis of cancer cells is the mainstream method. However, studies have reported that cancer cells' key features are resistance to apoptosis and chemotherapeutics. For high proliferation, cancer cells often have very active lipid metabolism and iron metabolism, which pave the way for ferroptosis. Interestingly, researchers found that drug-resistant or highly aggressive cancer cells are more prone to ferroptosis. Therefore, ferroptosis may be a potential strategy to eliminate cancer cells. In addition, links between ferroptosis and other diseases, such as neurological disorders and ischemia-reperfusion injury, have also been found. Understanding these diseases from the perspective of ferroptosis may provide new insights into clinical treatment. Herein, the metabolic processes in ferroptosis are reviewed, and the potential mechanisms and targets of ferroptosis in different diseases are summarized.

Multifunctional Fe3O4-PEI@HA nanoparticles in the ferroptosis treatment of hepatocellular carcinoma through modulating reactive oxygen species

Ferroptosis is a novel form of regulated cell death induced by iron-dependent lipid peroxidation imbalance. It has emerged as a promising antitumor therapeutic strategy in recent years. In this work, we successfully synthesized a complex magnetic nanocube Fe₃O₄ modified with PEI and HA by the thermal decomposition method. While loading a ferroptosis inducer RSL3 inhibited cancer cells through the ferroptosis signal transduction pathway. The drug delivery system could actively target tumor cells through an external magnetic field and HA-CD44 binding. Zeta potential analysis showed that Fe₃O₄-PEI@HA-RSL3 nanoparticles were more stable and uniformly dispersed in tumor acidic environment. Moreover, cellular experiments demonstrated that Fe₃O₄-PEI@HA-RSL3 nanoparticles could significantly inhibit the proliferation of hepatoma cells without a cytotoxic effect on normal hepatic cells. In addition, Fe₃O₄-PEI@HA-RSL3 played a vital role in ferroptosis by accelerating ROS production. The expression of ferroptosis-related genes Lactoferrin, FACL 4, GPX 4 and Ferritin was significantly suppressed with increasing treatment of Fe₃O₄-PEI@HA-RSL3 nanocubes. Therefore, this ferroptosis nanomaterial has great potential in Hepatocellular carcinoma (HCC) therapy.

Immunogenic cell death in cancer immunotherapy

Cancer immunotherapy has been acknowledged as a new paradigm for cancer treatment, with notable therapeutic effects on certain cancer types. Despite their significant potential, clinical studies over the past decade have revealed that cancer immunotherapy has low response rates in the majority of solid tumors. One of the key causes for poor responses is known to be the relatively low immunogenicity of solid tumors. Because most solid tumors are immune desert 'cold tumors' with antitumor immunity blocked from the onset of innate immunity, combination therapies that combine validated T-based therapies with approaches that can increase tumor-immunogenicity are being considered as relevant therapeutic options. This review paper focuses on immunogenic cell death (ICD) as a way of enhancing immunogenicity in tumor tissues. We will thoroughly review how ICDs such as necroptosis, pyroptosis, and ferroptosis can improve anti-tumor immunity and outline clinical trials targeting ICD. Finally, we will discuss the potential of ICD inducers. as an adjuvant for cancer immunotherapy.[BMB Reports 2023; 56(5): 275-286].

Immunogenic cell death in cancer immunotherapy

Cancer immunotherapy has been acknowledged as a new paradigm for cancer treatment, with notable therapeutic effects on certain cancer types. Despite their significant potential, clinical studies over the past decade have revealed that cancer immunotherapy has low response rates in the majority of solid tumors. One of the key causes for poor responses is known to be the relatively low immunogenicity of solid tumors. Because most solid tumors are immune desert 'cold tumors' with antitumor immunity blocked from the onset of innate immunity, combination therapies that combine validated T-based therapies with approaches that can increase tumor-immunogenicity are being considered as relevant therapeutic options. This review paper focuses on immunogenic cell death (ICD) as a way of enhancing immunogenicity in tumor tissues. We will thoroughly review how ICDs such as necroptosis, pyroptosis, and ferroptosis can improve anti-tumor immunity and outline clinical trials targeting ICD. Finally, we will discuss the potential of ICD inducers. as an adjuvant for cancer immunotherapy.[BMB Reports 2023; 56(5): 275-286].

Redox phospholipidomics discovers pro-ferroptotic death signals in A375 melanoma cells in vitro and in vivo

Growing cancer cells effectively evade most programs of regulated cell death, particularly apoptosis. This necessitates a search for alternative therapeutic modalities to cause cancer cell's demise, among them - ferroptosis. One of the obstacles to using pro-ferroptotic agents to treat cancer is the lack of adequate biomarkers of ferroptosis. Ferroptosis is accompanied by peroxidation of polyunsaturated species of phosphatidylethanolamine (PE) to hydroperoxy- (-OOH) derivatives, which act as death signals. We demonstrate that RSL3-induced death of A375 melanoma cells in vitro was fully preventable by ferrostatin-1, suggesting their high susceptibility to ferroptosis. Treatment of A375 cells with RSL3 caused a significant accumulation of PE-(18:0/20:4-OOH) and PE-(18:0/22:4-OOH), the biomarkers of ferroptosis, as well as oxidatively truncated products - PE-(18:0/hydroxy-8-oxo-oct-6-enoic acid (HOOA) and PC-(18:0/HOOA). A significant suppressive effect of RSL3 on melanoma growth was observed in vivo (utilizing a xenograft model of inoculation of GFP-labeled A375 cells into immune-deficient athymic nude mice). Redox phospholipidomics revealed elevated levels of 18:0/20:4-OOH in RSL3-treated group vs controls. In addition, PE-(18:0/20:4-OOH) species were identified as major contributors to the separation of control and RSL3-treated groups, with the highest variable importance in projection predictive score. Pearson correlation analysis revealed an association between tumor weight and contents of PE-(18:0/20:4-OOH) (r = -0.505), PE-18:0/HOOA (r = -0.547) and PE 16:0-HOOA (r = -0.503). Thus, LC-MS/MS based redox lipidomics is a sensitive and precise approach for the detection and characterization of phospholipid biomarkers of ferroptosis induced in cancer cells by radio- and chemotherapy.

Ferroptosis-modulating small molecules for targeting drug-resistant cancer: Challenges and opportunities in manipulating redox signaling

Ferroptosis is an iron-dependent cell death program that is characterized by excessive lipid peroxidation. Triggering ferroptosis has been proposed as a promising strategy to fight cancer and overcome drug resistance in antitumor therapy. Understanding the molecular interactions and structural features of ferroptosis-inducing compounds might therefore open the door to efficient pharmacological strategies against aggressive, metastatic, and therapy-resistant cancer. We here summarize the molecular mechanisms and structural requirements of ferroptosis-inducing small molecules that target central players in ferroptosis. Focus is placed on (i) glutathione peroxidase (GPX) 4, the only GPX isoenzyme that detoxifies complex membrane-bound lipid hydroperoxides, (ii) the cystine/glutamate antiporter system Xc - that is central for glutathione regeneration, (iii) the redox-protective transcription factor nuclear factor erythroid 2-related factor (NRF2), and (iv) GPX4 repression in combination with induced heme degradation via heme oxygenase-1. We deduce common features for efficient ferroptotic activity and highlight challenges in drug development. Moreover, we critically discuss the potential of natural products as ferroptosis-inducing lead structures and provide a comprehensive overview of structurally diverse biogenic and bioinspired small molecules that trigger ferroptosis via iron oxidation, inhibition of the thioredoxin/thioredoxin reductase system or less defined modes of action.

Ferroptosis regulates key signaling pathways in gastrointestinal tumors: Underlying mechanisms and therapeutic strategies

Ferroptosis is an emerging novel form of non-apoptotic, regulated cell death that is heavily dependent on iron and characterized by rupture in plasma membrane. Ferroptosis is distinct from other regulated cell death modalities at the biochemical, morphological, and molecular levels. The ferroptotic signature includes high membrane density, cytoplasmic swelling, condensed mitochondrial membrane, and outer mitochondrial rupture with associated features of accumulation of reactive oxygen species and lipid peroxidation. The selenoenzyme glutathione peroxidase 4, a key regulator of ferroptosis, greatly reduces the lipid overload and protects the cell membrane against oxidative damage. Ferroptosis exerts a momentous role in regulating cancer signaling pathways and serves as a therapeutic target in cancers. Dysregulated ferroptosis orchestrates gastrointestinal (GI) cancer signaling pathways leading to GI tumors such as colonic cancer, pancreatic cancer, and hepatocellular carcinoma. Crosstalk exists between ferroptosis and other cell death modalities. While apoptosis and autophagy play a detrimental role in tumor progression, depending upon the factors associated with tumor microenvironment, ferroptosis plays a decisive role in either promoting tumor growth or suppressing it. Several transcription factors, such as TP53, activating transcription factors 3 and 4, are involved in influencing ferroptosis. Importantly, several molecular mediators of ferroptosis, such as p53, nuclear factor erythroid 2-related factor 2/heme oxygenase-1, hypoxia inducible factor 1, and sirtuins, coordinate with ferroptosis in GI cancers. In this review, we elaborated on key molecular mechanisms of ferroptosis and the signaling pathways that connect ferroptosis to GI tumors.

Systemic Analyses of Cuproptosis-Related lncRNAs in Pancreatic Adenocarcinoma, with a Focus on the Molecular Mechanism of LINC00853

Pancreatic cancer (PC) is a deadly malignant digestive tumor with poor prognoses and a lack of effective treatment options. Cuproptosis, a recently identified copper-dependent programmed cell death type, has been implicated in multiple cancers. Long non-coding RNAs (lncRNAs) are also linked to the progression of PC. However, the role and prognostic values of cuproptosis-related lncRNAs in pancreatic adenocarcinoma (PAAD) remain unclear. In this study, we systemically analyzed the differential expressions and prognostic values of 672 cuproptosis-related lncRNAs in PAAD. Based on this, a prognostic signature including four lncRNAs (LINC00853, AC099850.3, AC010719.1, and AC006504.7) was constructed and was able to divide PAAD patients into high- and low-risk groups with significantly different prognoses. Next, we focused on lncRNA LINC00853. The differential expressions of LINC00853 between normal tissue and PAAD samples were validated by qRT-PCR. LINC00853 was knocked down by siRNA in PC cell lines BxPC-3 and PANC-1 and the oncogenic role of LINC00853 was validated by CCK8, colony formation, and EdU assays. Subsequently, LINC00853 knockdown cells were subjected to tumor xenograft tests and exhibited decreased tumor growth in nude mice. Mechanistically, knockdown of LINC00853 significantly reduced cellular glycolysis and enhanced cellular mitochondrial respiration levels in PC cells. Moreover, knockdown of LINC00853 decreased the protein level of a glycolytic kinase PFKFB3. Finally, glycolysis tests and functional tests using LINC00853 and HA-PFKFB3 indicated that the effects of LINC00853 on glycolysis and cell proliferation were mediated by PFKFB3. In conclusion, our systemic analyses have highlighted the important roles of cuproptosis-related lncRNAs in PAAD while the prognostic signature based on them showed excellent performance in PAAD patients and is expected to provide clinical guidance for individualized treatment. In addition, our findings provide a novel mechanism by which the LINC00853-PFKFB3 axis critically regulates aerobic glycolysis and cell proliferation in PC cells.