The induction of ferroptosis by impairing STAT3/Nrf2/GPx4 signaling enhances the sensitivity of osteosarcoma cells to cisplatin

Mitochondrial Quality Control in Ovarian Function: From Mechanisms to Therapeutic Strategies

Mitochondrial quality control plays a critical role in cytogenetic development by regulating various cell-death pathways and modulating the release of reactive oxygen species (ROS). Dysregulated mitochondrial quality control can lead to a broad spectrum of diseases, including reproductive disorders, particularly female infertility. Ovarian insufficiency is a significant contributor to female infertility, given its high prevalence, complex pathogenesis, and profound impact on women's health. Understanding the pathogenesis of ovarian insufficiency and devising treatment strategies based on this understanding are crucial. Oocytes and granulosa cells (GCs) are the primary ovarian cell types, with GCs regulated by oocytes, fulfilling their specific energy requirements prior to ovulation. Dysregulation of mitochondrial quality control through gene knockout or external stimuli can precipitate apoptosis, inflammatory responses, or ferroptosis in both oocytes and GCs, exacerbating ovarian insufficiency. This review aimed to delineate the regulatory mechanisms of mitochondrial quality control in GCs and oocytes during ovarian development. This study highlights the adverse consequences of dysregulated mitochondrial quality control on GCs and oocyte development and proposes therapeutic interventions for ovarian insufficiency based on mitochondrial quality control. These insights provide a foundation for future clinical approaches for treating ovarian insufficiency.

Golgi protein ACBD3 downregulation sensitizes cells to ferroptosis

Ferroptosis, a form of cell death driven by iron-dependent lipid peroxidation, is emerging as a promising target in cancer therapy. It is regulated by a network of molecules and pathways that modulate lipid metabolism, iron homeostasis and redox balance, and related processes. However, there are still numerous regulatory molecules intricately involved in ferroptosis that remain to be identified. Here, we indicated that suppression of Golgi protein acyl-coenzyme A binding domain A containing 3 (ACBD3) increased the sensitivity of Henrieta Lacks and PANC1 cells to ferroptosis. ACBD3 knockdown increases labile iron levels by promoting ferritinophagy. This increase in free iron, coupled with reduced levels of glutathione peroxidase 4 due to ACBD3 knockdown, leads to the accumulation of reactive oxygen species and lipid peroxides. Moreover, ACBD3 knockdown also results in elevated levels of polyunsaturated fatty acid-containing glycerophospholipids through mechanisms that remain to be elucidated. Furthermore, inhibition of ferrtinophagy in ACBD3 downregulated cells by knocking down the nuclear receptor co-activator 4 or Bafilomycin A1 treatment impeded ferroptosis. Collectively, our findings highlight the pivotal role of ACBD3 in governing cellular resistance to ferroptosis and suggest that pharmacological manipulation of ACBD3 levels is a promising strategy for cancer therapy.

Research progress on the role of lncRNA, circular RNA, and microRNA networks in regulating ferroptosis in osteosarcoma

Noncoding RNAs (ncRNAs) do not participate in protein-coding. Ferroptosis is a newly discovered form of cell death mediated by reactive oxygen species and lipid peroxidation. Recent studies have shown that ncRNAs such as microRNAs, long noncoding RNAs, circular RNAs, and ferroptosis are involved in the occurrence and development of osteosarcoma (OS). Studies have confirmed that ncRNAs participate in the development of OS by regulating the ferroptosis. However, systematic summary on this topic are still lacking. This review summarises the potential role of ncRNAs in the diagnosis, treatment, drug resistance, and prognosis of OS and the basis for diagnosing, preventing, and treating clinical OS and developing effective drugs. This review summarises the latest research progress on ncRNAs that regulate ferroptosis in OS, attempts to clarify the molecular mechanisms by which ncRNAs regulate ferroptosis in the pathogenesis of OS, and elaborates on the involvement of ferroptosis in OS from the perspective of ncRNAs.

Prolactin is an Endogenous Antioxidant Factor in Astrocytes That Limits Oxidative Stress-Induced Astrocytic Cell Death via the STAT3/NRF2 Signaling Pathway

Oxidative stress-induced death of neurons and astrocytes contributes to the pathogenesis of numerous neurodegenerative diseases. While significant progress has been made in identifying neuroprotective molecules against neuronal oxidative damage, little is known about their counterparts for astrocytes. Prolactin (PRL), a hormone known to stimulate astroglial proliferation, viability, and cytokine expression, exhibits antioxidant effects in neurons. However, its role in protecting astrocytes from oxidative stress remains unexplored. Here, we investigated the effect of PRL against hydrogen peroxide (H2O2)-induced oxidative insult in primary cortical astrocyte cultures. Incubation of astrocytes with PRL led to increased enzymatic activity of superoxide dismutase (SOD) and glutathione peroxidase (GPX), resulting in higher total antioxidant capacity. Concomitantly, PRL prevented H2O2-induced cell death, reactive oxygen species accumulation, and protein and lipid oxidation. The protective effect of PRL upon H2O2-induced cell death can be explained by the activation of both signal transducer and activator of transcription 3 (STAT3) and NFE2 like bZIP transcription factor 2 (NRF2) transduction cascades. We demonstrated that PRL induced nuclear translocation and transcriptional upregulation of Nrf2, concurrently with the transcriptional upregulation of the NRF2-dependent genes heme oxygenase 1, Sod1, Sod2, and Gpx1. Pharmacological blockade of STAT3 suppressed PRL-induced transcriptional upregulation of Nrf2, Sod1 and Gpx1 mRNA, and SOD and GPX activities. Furthermore, genetic ablation of the PRL receptor increased astroglial susceptibility to H2O2-induced cell death and superoxide accumulation, while diminishing their intrinsic antioxidant capacity. Overall, these findings unveil PRL as a potent antioxidant hormone that protects astrocytes from oxidative insult, which may contribute to brain neuroprotection.

Advance on combination therapy strategies based on biomedical nanotechnology induced ferroptosis for cancer therapeutics

Globally, cancer is a serious health problem. It is unfortunate that current anti-cancer strategies are insufficiently specific and damage the normal tissues. There's urgent need for development of new anti-cancer strategies. More recently, increasing attention has been paid to the new application of ferroptosis and nano materials in cancer research. Ferroptosis, a condition characterized by excessive reactive oxygen species-induced lipid peroxidation, as a new programmed cell death mode, exists in the process of a number of diseases, including cancers, neurodegenerative disease, cerebral hemorrhage, liver disease, and renal failure. There is growing evidence that inducing ferroptosis has proven to be an effective strategy against a variety of chemo-resistant cancer cells. Nano-drug delivery system based on nanotechnology provides a highly promising platform with the benefits of precise control of drug release and reduced toxicity and side effects. This paper reviews the latest advances of combination therapy strategies based on biomedical nanotechnology induced ferroptosis for cancer therapeutics. Given the new chances and challenges in this emerging area, we need more attention to the combination of nanotechnology and ferroptosis in the treatment of cancer in the future.

TCF12 induces ferroptosis by suppressing OTUB1-mediated SLC7A11 deubiquitination to promote cisplatin sensitivity in oral squamous cell carcinoma

Chemotherapy resistance is a major obstacle to effective cancer treatment, and promotion of ferroptosis can suppress cisplatin resistance in tumor cells. TCF12 plays a suppressive role in oral squamous cell carcinoma (OSCC), but whether it participates in the regulation of cisplatin resistance by modulating ferroptosis remains unclear. Here, we found that TCF12 expression was decreased in OSCC cells compared with normal oral cells, and it was reduced in cisplatin (DDP)-resistant OSCC cells compared with parental cells. Moreover, overexpression of TCF12 sensitized DDP-resistant cells to DDP by promoting ferroptosis. Intriguingly, silencing TCF12 reversed the promotion effect of the ferroptosis activator RSL3 on ferroptosis and DDP sensitivity, and overexpressing TCF12 antagonized the effect of the ferroptosis inhibitor liproxstatin-1 on ferroptosis and DDP resistance. Mechanically, TCF12 promoted ubiquitination of SLC7A11 and decreased SLC7A11 protein stability through transcriptional repression of OTUB1, thereby facilitating ferroptosis. Consistently, SLC7A11 overexpression neutralized the promotion effect of TCF12 on ferroptosis and DDP sensitivity. Additionally, upregulation of TCF12 hindered the growth of mouse OSCC xenografts and enhanced the DDP sensitivity of xenografts by inducing ferroptosis. In conclusion, TCF12 enhanced DDP sensitivity in OSCC cells by promoting ferroptosis, which was achieved through modulating SLC7A11 expression via transcriptional regulation of OTUB1.

Casticin induces ferroptosis in human osteosarcoma cells through Fe2+ overload and ROS production mediated by HMOX1 and LC3-NCOA4

Osteosarcoma is a primary solid bone malignancy, and surgery + chemotherapy is the most commonly used treatment. However, chemotherapeutic drugs can cause a range of side effects. Casticin, a polymethoxyflavonoid, has anti-tumor therapeutic effects. This study is aim to investigate the anti-osteosarcoma activity of casticin and explore the mechanism. Crystal violet staining, MTT assay, colony formation assay, wound healing assay, transwell assay, hoechst 33,258 staining, and flow cytometry analysis were used to investigate the effects of casticin on proliferation, migration, invasion, and apoptosis of osteosarcoma cells in vitro. The intracellular Fe2+, ROS, MDA, GSH/GSSG content changes were detected using the corresponding assay kits. The mRNA sequencing + bioinformatics analysis and western blot were used to detect the possible mechanism. We found that casticin caused G2/M phase cell cycle arrest in human osteosarcoma cells, inhibited the migration and invasion, and induced cell apoptosis and ferroptosis. Mechanistic studies showed the ferroptosis pathway was enriched stronger than apoptosis. Casticin up-regulated the expression of HMOX1, LC3 and NCOA4, meanwhile it activated MAPK signaling pathways. Animal experiments proved that casticin also inhibited the growth and metastasis of osteosarcoma cell xenograft tumor in vivo. In conclusion, casticin can induce ferroptosis in osteosarcoma cells through Fe2+ overload and ROS production mediated by HMOX1 and LC3-NCOA4. This provides a new strategy for osteosarcoma treatment.

Metal-organic framework-mediated siRNA delivery and sonodynamic therapy for precisely triggering ferroptosis and augmenting ICD in osteosarcoma

The complex genomics, immunosuppressive tumor microenvironment (TME), and chemotherapeutic resistance of osteosarcoma (OS) have resulted in limited therapeutic effects in the clinic. Ferroptosis is involved in tumor progression and is regulated mainly by glutathione peroxidase 4 (GPX4). Small interfering RNA (siRNA)-based RNA interference (RNAi) can precisely target any gene. However, achieving effective siRNA delivery is highly challenging. Here, we fabricated a TME-responsive metal-organic framework (MOF)-based biomimetic nanosystem (mFeP@si) with siGPX4 delivery and sonodynamic therapy (SDT) to treat OS by targeting ferroptosis. Under ultrasound (US) irradiation, mFeP@si achieves lysosomal escape via singlet oxygen (1O2)-mediated lysosomal membrane disruption and then accelerates ROS generation and glutathione (GSH) depletion. Meanwhile, siGPX4 silences GPX4 expression by binding to GPX4 mRNA and leads to the accumulation of toxic phospholipid hydroperoxides (PL-OOH), further magnifying the ROS storm and triggering ferroptosis. Notably, synergistic therapy remarkably enhances antitumor effects, improves the immunosuppressive TME by inducing potent immunogenic cell death (ICD), and increases the sensitivity of chemotherapy-resistant OS cells to cisplatin. Overall, this novel nanosystem, which targets ferroptosis by integrating RNAi and SDT, exhibits strong antitumor effects both in vitro and in vivo, providing new insights for treating OS.

Blue light induced ferroptosis via STAT3/GPX4/SLC7A11/FTH1 in conjunctiva epithelium in vivo and in vitro

The prevalence of Light-emitting diodes (LEDs) has exposed us to an excessive amount of blue light (BL) which causes various ophthalmic diseases. Previous studies have shown that conjunctiva is vulnerable to BL. In this study, we aimed to investigate the underlying mechanism of BL-induced injury in conjunctiva. We placed C57BL/6 mice and human conjunctival epithelial cell lines (HCECs) under BL (440 nm ± 15 nm, 0.2 mW/cm2) to establish a BL injury model in vivo and in vitro. Immunohistochemistry and MDA assay were used to identify lipid peroxidation (LPO) in vivo. HE staining was applied to detect morphological damage of conjunctival epithelium. DCFH-DA, C11-BODIPY 581/591, Calcein-AM, and FeRhoNox™-1 probes were performed to identify ferroptosis levels in vitro. Real-time qPCR and Western blotting techniques were employed to uncover signaling pathways of blue light-induced ferroptosis. Our findings demonstrated that BL affected tear film instability and induced conjunctival epithelium injury in vivo. Ferrostatin-1 significantly alleviated blue light-induced ferroptosis in vivo and in vitro. BL downregulates the levels of solute carrier family 7 member 11 (SLC7A11), Ferritin heavy chain (FTH1), and glutathione peroxidase (GPX4) by inhibiting the activation and translocation of the Signal transducer and activator of transcription 3 (STAT3) from inducing Fe2+ burst, ROS and LPO accumulation, ultimately resulting in ferroptosis. This study will offer new insight into BL-induced conjunctival injury and LED-induced dry eye.

Ferroptosis defense mechanisms: The future and hope for treating osteosarcoma

Currently, challenges such as chemotherapy resistance, resulting from preoperative and postoperative chemotherapy, postoperative recurrence, and poor bone regeneration quality, are becoming increasingly prominent in osteosarcoma (OS) treatment. There is an urgent need to find more effective ways to address these issues. Ferroptosis is a novel form of iron-dependent programmed cell death, distinct from other forms of cell death. In this paper, we summarize how, through the three major defense systems of ferroptosis, not only can substances from traditional Chinese medicine, antitumor drugs, and nano-drug carriers induce ferroptosis in OS cells, but they can also be combined with immunotherapy, differentiation therapy, and other treatment modalities to significantly enhance chemotherapy sensitivity and inhibit tumor growth. Thus, ferroptosis holds great potential in treating OS, offering more choices and possibilities for future clinical interventions.

CircORC2 promoted proliferation and inhibited the sensitivity of osteosarcoma cell lines to cisplatin by regulating the miR-485-3p/TRIM2 axis

Resistance to chemotherapy leads to poor prognosis for osteosarcoma (OS) patients. However, due to the high metastasis of tumor and the decrease in sensitivity of tumor cells to cisplatin (DDP), the 5-year survival rate of OS patients is still unsatisfactory. This study explored a mechanism for improving the sensitivity of OS cells to DDP. A DDP-resistant OS cell model was established, and we have found that circORC2 and TRIM2 were upregulated in DDP-resistant OS cells, but miR-485-3p was downregulated. The cell viability and proliferation of the OS cells decreased gradually with the increase of DDP dose, but a gradual increase in apoptosis was noted. CircORC2 promoted OS cell proliferation and DDP resistance and upregulated TRIM2 expression by targeting miR-485-3p. Functionally, circORC2 downregulated miR-485-3p to promote OS cell proliferation and inhibit DDP sensitivity. Additionally, it promoted cell proliferation and inhibited the sensitivity of DDP by regulating the miR-485-3p/TRIM2 axis. In conclusion, circORC2 promoted cell proliferation and inhibited the DDP sensitivity in OS cells via the miR-485-3p/TRIM2 axis. These findings indicated the role of circORC2 in regulating the sensitivity of OS cells to DDP.

Natural products and the balancing act of autophagy-dependent/independent ferroptosis in cancer therapy

The control of biological cell death is essential for the body's appropriate growth. The resistance of cells to the apoptotic process presents a new difficulty in the treatment of cancer. To combat cancer cells, researchers are working to find new apoptotic pathways and components to activate. One of the processes of regulated cell death (RCD) is referred to as ferroptosis marked by a decline in the activity of lipid glutathione peroxidase 4 (GPX4) after the buildup of reactive oxygen species (ROS). Since lipid peroxidation is a crucial component of ferroptosis and is required for its start, numerous medicines have been studied, particularly for the treatment of cancer. In this context, autophagy is an additional form of RCD that can govern ferroptosis through shared signaling pathways/factors involved in both mechanisms. In this review, we will explore the molecular mechanisms underlying ferroptosis and its association with autophagy, to gain fresh insights into their interplay in cancer advancement, and the potential of natural products for its treatment.

Transcriptome and single-cell analysis reveal disulfidptosis-related modification patterns of tumor microenvironment and prognosis in osteosarcoma

Osteosarcoma (OS) is the most common malignant bone tumor with high pathological heterogeneity. Our study aimed to investigate disulfidptosis-related modification patterns in OS and their relationship with survival outcomes in patients with OS. We analyzed the single-cell-level expression profiles of disulfidptosis-related genes (DSRGs) in both OS microenvironment and OS subclusters, and HMGB1 was found to be crucial for intercellular regulation of OS disulfidptosis. Next, we explored the molecular clusters of OS based on DSRGs and related immune cell infiltration using transcriptome data. Subsequently, the hub genes of disulfidptosis in OS were screened by applying multiple machine models. In vitro and patient experiments validated our results. Three main disulfidptosis-related molecular clusters were defined in OS, and immune infiltration analysis suggested high immune heterogeneity between distinct clusters. The in vitro experiment confirmed decreased cell viability of OS after ACTB silencing and higher expression of ACTB in patients with lower immune scores. Our study systematically revealed the underlying relationship between disulfidptosis and OS at the single-cell level, identified disulfidptosis-related subtypes, and revealed the potential role of ACTB expression in OS disulfidptosis.

Lipid Peroxidation-Related Redox Signaling in Osteosarcoma

Oxidative stress and lipid peroxidation play important roles in numerous physiological and pathological processes, while the bioactive products of lipid peroxidation, lipid hydroperoxides and reactive aldehydes, act as important mediators of redox signaling in normal and malignant cells. Many types of cancer, including osteosarcoma, express altered redox signaling pathways. Such redox signaling pathways protect cancer cells from the cytotoxic effects of oxidative stress, thus supporting malignant transformation, and eventually from cytotoxic anticancer therapies associated with oxidative stress. In this review, we aim to explore the status of lipid peroxidation in osteosarcoma and highlight the involvement of lipid peroxidation products in redox signaling pathways, including the involvement of lipid peroxidation in osteosarcoma therapies.

Advances in prognostic models for osteosarcoma risk

The risk prognosis model is a statistical model that uses a set of features to predict whether an individual will develop a specific disease or clinical outcome. It can be used in clinical practice to stratify disease severity and assess risk or prognosis. With the advancement of large-scale second-generation sequencing technology, along Prognosis models for osteosarcoma are increasingly being developed as large-scale second-generation sequencing technology advances and clinical and biological data becomes more abundant. This expansion greatly increases the number of prognostic models and candidate genes suitable for clinical use. This article will present the predictive effects and reliability of various prognosis models, serving as a reference for their evaluation and application.

Nox2 inhibition reduces trophoblast ferroptosis in preeclampsia via the STAT3/GPX4 pathway

AIMS

Ferroptosis, a novel mode of cell death characterized by lipid peroxidation and oxidative stress, plays an important role in the pathogenesis of preeclampsia (PE). The aim of this study is to determine the role of Nox2 in the ferroptosis of trophoblast cells, along with the underlying mechanisms.

METHODS

The mRNA and protein levels of Nox2, STAT3, and GPX4 in placental tissues and trophoblast cells were respectively detected by qRT-PCR and western blot analysis. CCK8, transwell invasion and tube formation assays were used to evaluate the function of trophoblast cells. Ferroptosis was evaluated using flow cytometry and the lipid peroxidation assay. Glycolysis and mitochondrial respiration were investigated by detecting the extracellular acidification rate (ECAR) and oxygen consumption rate (OCR) using Seahorse extracellular flux technology. The t-test or one-way ANOVA was used for statistical analysis.

KEY FINDINGS

Nox2 was up-regulated while STAT3 and GPX4 were down-regulated in PE placental tissues. Nox2 knockdown inhibited ferroptosis in trophoblast cells, which was shown by enhanced proliferation and invasion, decreased ROS and lipid peroxide levels, and reduced glycolysis and mitochondrial dysfunction. Nox2 negatively correlated with MVD in PE placentas, and Nox2 knockdown restored ferroptosis-inhibited tube formation. Nox2 could interact with STAT3. Inhibiting Nox2 restored ferroptosis-induced alterations in the mRNA and protein levels of STAT3 and GPX4.

SIGNIFICANCE

Nox2 may trigger ferroptosis through the STAT3/GPX4 pathway, subsequently leading to regulation of mitochondrial respiration, transition of glycolysis, and inhibition of placental angiogenesis. Therefore, targeted inhibition of Nox2 is expected to become a new therapeutic target for PE.

Targeting ferroptosis for leukemia therapy: exploring novel strategies from its mechanisms and role in leukemia based on nanotechnology

The latest findings in iron metabolism and the newly uncovered process of ferroptosis have paved the way for new potential strategies in anti-leukemia treatments. In the current project, we reviewed and summarized the current role of nanomedicine in the treatment and diagnosis of leukemia through a comparison made between traditional approaches applied in the treatment and diagnosis of leukemia via the existing investigations about the ferroptosis molecular mechanisms involved in various anti-tumor treatments. The application of nanotechnology and other novel technologies may provide a new direction in ferroptosis-driven leukemia therapies. The article explores the potential of targeting ferroptosis, a new form of regulated cell death, as a new therapeutic strategy for leukemia. It discusses the mechanisms of ferroptosis and its role in leukemia and how nanotechnology can enhance the delivery and efficacy of ferroptosis-inducing agents. The article not only highlights the promise of ferroptosis-targeted therapies and nanotechnology in revolutionizing leukemia treatment, but also calls for further research to overcome challenges and fully realize the clinical potential of this innovative approach. Finally, it discusses the challenges and opportunities in clinical applications of ferroptosis.

Sestrin2 ameliorates diabetic retinopathy by regulating autophagy and ferroptosis

Diabetic retinopathy (DR) is a serious microvascular complication of diabetes. The aim of this study was to explore the effect of Sestrin2 on DR through the regulation of autophagy and ferroptosis levels and its mechanism. In vitro and in vivo DR models were established by high glucose (HG) and streptozotocin (STZ) induction of ARPE-19 human retinal pigment epithelial cells and C57BL/6 mice, respectively. In this study, we demonstrated that after HG treatment, the activity of ARPE-19 cells was decreased, the apoptosis rate was increased, endoplasmic reticulum (ER) stress was activated, autophagy levels were decreased, and ferroptosis levels were increased. Overexpression of Sestrin2 enhanced cell viability, reduced apoptosis and ferroptosis, and enhanced autophagy. However, the effect of overexpression of Sestrin2 was attenuated after the addition of the STAT3 phosphorylation activator Colivelin TFA (C-TFA), the mTOR pathway activator MHY1485 or the autophagy inhibitor 3-methyladenine (3-MA). In addition, the effect of Sestrin2 knockdown on cells was opposite to the effect of overexpression of Sestrin2, while the effect of Sestrin2 knockdown was attenuated after treatment with the ER stress inhibitor 4-phenylbutyric acid (4-PBA). Animal experiments also confirmed the results of cell experiments and attenuated the effects of overexpression of Sestrin2 after injection of the ferroptosis activators erastin or 3-MA. Our study revealed that Sestrin2 inhibits ferroptosis by inhibiting STAT3 phosphorylation and ER stress and promoting autophagy levels, thereby alleviating DR.

Harnessing ferroptosis for enhanced sarcoma treatment: mechanisms, progress and prospects

Sarcoma is a malignant tumor that originates from mesenchymal tissue. The common treatment for sarcoma is surgery supplemented with radiotherapy and chemotherapy. However, patients have a 5-year survival rate of only approximately 60%, and sarcoma cells are highly resistant to chemotherapy. Ferroptosis is an iron-dependent nonapoptotic type of regulated programmed cell death that is closely related to the pathophysiological processes underlying tumorigenesis, neurological diseases and other conditions. Moreover, ferroptosis is mediated via multiple regulatory pathways that may be targets for disease therapy. Recent studies have shown that the induction of ferroptosis is an effective way to kill sarcoma cells and reduce their resistance to chemotherapeutic drugs. Moreover, ferroptosis-related genes are related to the immune system, and their expression can be used to predict sarcoma prognosis. In this review, we describe the molecular mechanism underlying ferroptosis in detail, systematically summarize recent research progress with respect to ferroptosis application as a sarcoma treatment in various contexts, and point out gaps in the theoretical research on ferroptosis, challenges to its clinical application, potential resolutions of these challenges to promote ferroptosis as an efficient, reliable and novel method of clinical sarcoma treatment.

Ferulic acid protects against gamma-radiation induced liver injury via regulating JAK/STAT/Nrf2 pathways

This study aims to evaluate the effect and underlying mechanism of ferulic acid (FA) in alleviating the acute liver injury by ionizing radiation (IR) in vivo. Rats were divided into 4groups (Groups: control, 6Gy irradiated (IRR), FA (50 mg/kg) and FA + IRR). The results showed that FA can effectively inhibit liver damage and restore the structure and function of the liver. In mechanism, FA prevented IR-induced liver fibrosis and blocked the JAK/STAT signaling pathway to effectively inhibit the hepatic inflammatory response; and inhibited IR-induced oxidative stress (OS) by upregulating the Nrf2 signaling pathway and promoting the synthesis of several antioxidants. Moreover, FA inhibited ferroptosis in the liver by stimulating the expression of GPX4 and SLC7A11. FA reduced lipid peroxidation by downregulation of the reactive oxygen species (ROS) production and iron aggregation, thus inhibiting ferroptosis and alleviating IR-induced liver injury. In conclusion, the current study suggests the potential complex mechanisms underlying the mitigating impact of FA in IR-induced ferroptotic liver damage.

Ferroptosis and EMT resistance in cancer: a comprehensive review of the interplay

Ferroptosis differs from traditional cell death mechanisms like apoptosis, necrosis, and autophagy, primarily due to its reliance on iron metabolism and the loss of glutathione peroxidase activity, leading to lipid peroxidation and cell death. The dysregulation of iron metabolism is a hallmark of various cancers, contributing to tumor progression, metastasis, and notably, drug resistance. The acquisition of mesenchymal characteristics by epithelial cells is known as Epithelial-Mesenchymal Transition (EMT), a biological process intricately linked to cancer development, promoting traits such as invasiveness, metastasis, and resistance to therapeutic interventions. EMT plays a pivotal role in cancer progression and contributes significantly to the complex dynamics of carcinogenesis. Research findings indicate that mesenchymal cancer cells exhibit greater susceptibility to ferroptosis compared to their epithelial counterparts. The induction of ferroptosis becomes more effective in eliminating drug-resistant cancer cells during the process of EMT. The interplay between ferroptosis and EMT, a process where epithelial cells transform into mobile mesenchymal cells, is crucial in understanding cancer progression. EMT is associated with increased cancer metastasis and drug resistance. The review delves into how ferroptosis and EMT influence each other, highlighting the role of key proteins like GPX4, which protects against lipid peroxidation, and its inhibition can induce ferroptosis. Conversely, increased GPX4 expression is linked to heightened resistance to ferroptosis in cancer cells. Moreover, the review discusses the implications of EMT-induced transcription factors such as Snail, Zeb1, and Twist in modulating the sensitivity of tumor cells to ferroptosis, thereby affecting drug resistance and cancer treatment outcomes. Targeting the ferroptosis pathway offers a promising therapeutic strategy, particularly for tumors resistant to conventional treatments. The induction of ferroptosis in these cells could potentially overcome drug resistance. However, translating these findings into clinical practice presents challenges, including understanding the precise mechanisms of ferroptosis induction, identifying predictive biomarkers, and optimizing combination therapies. The review underscores the need for further research to unravel the complex interactions between ferroptosis, EMT, and drug resistance in cancer. This could lead to the development of more effective, targeted cancer treatments, particularly for drug-resistant tumors, offering new hope in cancer therapeutics.

SRSF1 inhibits ferroptosis and reduces cisplatin chemosensitivity of triple-negative breast cancer cells through the circSEPT9/GCH1 axis

Cisplatin (DDP) is a commonly used chemotherapeutic agent for triple negative breast cancer (TNBC), but its efficacy can be limited by chemoresistance. This study aimed to explore the functional mechanism of SR-rich splicing factor 1 (SRSF1) in DDP chemosensitivity of TNBC cells. Levels of SRSF1, circular RNA septin 9 (circSEPT9), and GTP cyclohydrolase-1 (GCH1) in TNBC cells, DDP-resistant cells, and normal cells were determined. Cell viability, half-maximal inhibitory concentration (IC50) value, and proliferation were evaluated. Ferroptosis was determined by assay kits (ferric ion/ROS/MDA/GSH) and Western blot assay (SLC7A11/ACSL4). The genetic binding was analyzed by RNA immunoprecipitation and RNA pull-down assays. SRSF1, circSEPT9, and GCH1 were upregulated in TNBC cells. SRSF1 downregulation reduced IC50 to DDP of parent and drug-resistant TNBC cells and inhibited cell viability and proliferation, meanwhile, the downregulation reduced GSH/SLC7A11 levels while elevated ferric ion/ROS/MDA/ACSL4 levels, promoting ferroptosis. SRSF1 bound to and upregulated circSEPT9 and circSEPT9 blocked the ubiquitination of GCH1, thereby increasing GCH1 protein level. Overexpression of circSEPT9 and GCH1 attenuated the DDP chemosensitivity of TNBC cells by inhibiting ferroptosis. This study is the first to report the role of SRSF1 inhibitors combined with chemotherapy in TNBC, which provides a promising strategy for the treatment of TNBC. SIGNIFICANCE: Cisplatin (DDP) is a commonly used chemotherapeutic agent for triple negative breast cancer (TNBC), but its efficacy can be limited by chemoresistance. This study aimed to unravel the molecular mechanism of SR-rich splicing factor 1 (SRSF1) in DDP chemosensitivity of TNBC cells.

1,4-dihydroxy quininib activates ferroptosis pathways in metastatic uveal melanoma and reveals a novel prognostic biomarker signature

Uveal melanoma (UM) is an ocular cancer, with propensity for lethal liver metastases. When metastatic UM (MUM) occurs, as few as 8% of patients survive beyond two years. Efficacious treatments for MUM are urgently needed. 1,4-dihydroxy quininib, a cysteinyl leukotriene receptor 1 (CysLT1) antagonist, alters UM cancer hallmarks in vitro, ex vivo and in vivo. Here, we investigated the 1,4-dihydroxy quininib mechanism of action and its translational potential in MUM. Proteomic profiling of OMM2.5 cells identified proteins differentially expressed after 1,4-dihydroxy quininib treatment. Glutathione peroxidase 4 (GPX4), glutamate-cysteine ligase modifier subunit (GCLM), heme oxygenase 1 (HO-1) and 4 hydroxynonenal (4-HNE) expression were assessed by immunoblots. Biliverdin, glutathione and lipid hydroperoxide were measured biochemically. Association between the expression of a specific ferroptosis signature and UM patient survival was performed using public databases. Our data revealed that 1,4-dihydroxy quininib modulates the expression of ferroptosis markers in OMM2.5 cells. Biochemical assays validated that GPX4, biliverdin, GCLM, glutathione and lipid hydroperoxide were significantly altered. HO-1 and 4-HNE levels were significantly increased in MUM tumor explants from orthotopic patient-derived xenografts (OPDX). Expression of genes inhibiting ferroptosis is significantly increased in UM patients with chromosome 3 monosomy. We identified IFerr, a novel ferroptosis signature correlating with UM patient survival. Altogether, we demontrated that in MUM cells and tissues, 1,4-dihydroxy quininib modulates key markers that induce ferroptosis, a relatively new type of cell death driven by iron-dependent peroxidation of phospholipids. Furthermore, we showed that high expression of specific genes inhibiting ferroptosis is associated with a worse UM prognosis, thus, the IFerr signature is a potential prognosticator for which patients develop MUM. All in all, ferroptosis has potential as a clinical biomarker and therapeutic target for MUM.

Synergistic antitumor efficacy of gemcitabine and cisplatin to induce ferroptosis in pancreatic ductal adenocarcinoma via Sp1-SAT1-polyamine metabolism pathway

PURPOSE

The combination of cisplatin and gemcitabine-based chemotherapy has been recommended as a preferred regimen for pancreatic ductal adenocarcinoma (PDAC) patients with germline-based mutations. However, the underlying mechanism remains poorly elucidated. Therefore, our study aimed to explore the mechanistic basis of the cell-killing activity of gemcitabine plus cisplatin and identify potential therapeutic targets.

METHODS

First, we explored the synergistic cytotoxic effects of gemcitabine and cisplatin on PDAC through in vitro and in vivo experiments. Then, we investigated ferroptosis-related biomarkers, to assess the impact of the combination therapy on ferroptosis. Using bioinformatics methods, we identified SAT1 as a potential key mediator of ferroptosis induced by gemcitabine and cisplatin. We tested the polyamine levels in PDAC cells by LC-MS after overexpressed or knocked down SAT1, and explored the role of polyamines in ferroptosis using exogenous supplementation. Finally, we explored the regulatory effect of Sp1 on SAT1 through ChIP-qPCR and dual-luciferase reporter assay.

RESULTS

Gemcitabine plus cisplatin enhanced cell death and induced ferroptosis in PDAC. This combination upregulated SAT1 transcription by inhibiting Sp1. SAT1 activation promoted the catabolism of spermine and spermidine, leading to iron accumulation and lipid peroxide generation, ultimately resulting in ferroptosis.

CONCLUSIONS

In summary, our findings suggested the gemcitabine and cisplatin combination therapy induced ferroptosis in a GSH-independent manner in PDAC. The combined treatment inhibited Sp1 and upregulated SAT1 transcription, leading to the breakdown of spermine and spermidine. Therefore, targeting SAT1-induced polyamine metabolism may represent a promising therapeutic strategy for PDAC.

Effect of traditional Chinese medicine in osteosarcoma: Cross-interference of signaling pathways and potential therapeutic targets

Osteosarcoma (OS) has a high recurrence rate, disability rate, mortality and metastasis, it brings great economic burden and psychological pressure to patients, and then seriously affects the quality of life of patients. At present, the treatment methods of OS mainly include radiotherapy, chemotherapy, surgical therapy and neoadjuvant chemotherapy combined with limb salvage surgery. These treatment methods can relieve the clinical symptoms of patients to a certain extent, and also effectively reduce the disability rate, mortality and recurrence rate of OS patients. However, because metastasis of tumor cells leads to new complications, and OS cells become resistant with prolonged drug intervention, which reduces the sensitivity of OS cells to drugs, these treatments still have some limitations. More and more studies have shown that traditional Chinese medicine (TCM) has the characteristics of "multiple targets and multiple pathways," and can play an important role in the development of OS through several key signaling pathways, including PI3K/AKT, Wnt/β-catenin, tyrosine kinase/transcription factor 3 (JAK/STAT3), Notch, transforming growth factor-β (TGF-β)/Smad, nuclear transcription factor-κB (NF-κB), mitogen-activated protein kinase (MAPK), nuclear factor E2-related factor 2 (Nrf2), Hippo/YAP, OPG/RANK/RANKL, Hedgehog and so on. In this paper, the signaling pathways of cross-interference between active ingredients of TCM and OS were reviewed, and the development status of novel OS treatment was analyzed. The active ingredients in TCM can provide therapeutic benefits to patients by targeting the activity of signaling pathways. In addition, potential strategies for targeted therapy of OS by using ferroptosis were discussed. We hope to provide a unique insight for the in-depth research and clinical application of TCM in the fields of OS growth, metastasis and chemotherapy resistance by understanding the signaling crosstalk between active ingredients in TCM and OS.

Tremella fuciformis polysaccharides induce ferroptosis in Epstein-Barr virus-associated gastric cancer by inactivating NRF2/HO-1 signaling

Approximately 10% of gastric cancers are associated with Epstein-Barr virus (EBV). Tremella fuciformis polysaccharides (TFPs) are characterized by antioxidative and anti-inflammatory effects in different diseases. However, whether TFP improves EBV-associated gastric cancer (EBVaGC) has never been explored. The effects of TFP on EBV-infected GC cell viability were determined using a CCK-8 assay and flow cytometry. Western blotting and RT-qPCR were performed to explore the expression of ferroptosis-related proteins. The CCK-8 assay showed that TFP decreased EBV-infected GC cell viability in a dose- and time-dependent manner. Flow cytometry assays indicated that TFP significantly induced EBV-infected GC cell death. TFP also reduced the migratory capacity of EBV-infected GC cells. Furthermore, treatment with TFP significantly increased the mRNA levels of PTGS2 and Chac1 in EBV-infected GC cells. Western blot assays indicated that TFP suppressed the expression of NRF2, HO-1, GPX4 and xCT in EBV-infected GC cells. More importantly, overexpression of NRF2 could obviously rescue TFP-induced downregulation of GPX4 and xCT in EBV-infected GC cells. In summary, we showed novel data that TFP induced ferroptosis in EBV-infected GC cells by inhibiting NRF2/HO-1 signaling. The current findings may shed light on the potential clinical application of TFP in the treatment of EBVaGC.

Baicalin inhibits IL-1β-induced ferroptosis in human osteoarthritis chondrocytes by activating Nrf-2 signaling pathway

BACKGROUND

Osteoarthritis (OA) is a common degenerative disease involving articular cartilage, in which ferroptosis of chondrocytes plays an important role. Baicalin (BAI) exerts regulatory effects in a wide range of orthopedic diseases including OA, but its effect on ferroptosis of chondrocytes (CHs) is still unclear. The purpose of this study was to determine the effect of BAI on ferroptosis in human OA chondrocytes (OACs), and to explore its possible mechanism.

METHODS

CHs were treated with IL-1β (10 ng/mL) to simulate inflammation in vitro. Immunofluorescence, quantitative RT-PCR, Western blotting and cell viability assay were performed to evaluate the impacts of BAI on Fe2+ level, mitochondrial dysfunction, ferroptosis-related proteins, oxidative stress and cytotoxicity in CHs. Additionally, siRNA was made use of to knock out nuclear factor E2-related factor 2 (Nrf2) to analyze the role played by Nrf2 in BAI-induced CH ferroptosis.

RESULTS

BAI eliminated IL-1β-induced Fe2+ accumulation, changes in mitochondrial membrane potential and ferroptosis-related protein GPX4, SLC7A11, P53 and ACSL4 levels, as well as reactive oxygen species (ROS), lipid peroxidation (LPO) and malondialdehyde (MDA) accumulation in CHs. Besides, BAI reversed IL-1β-induced decrease of Collagen II and increase of MMP13 in CHs. Meanwhile, BAI attenuated IL-1β-induced CH toxicity and promoted Nrf2 antioxidant system activation. When Nrf2 was knocked down by siRNA, the effects of BAI on IL-1β-induced ferroptosis-related proteins and antioxidant stress in CHs were significantly weakened.

CONCLUSIONS

This study demonstrates that IL-1β can induce CH ferroptosis. BAI is able to inhibit IL-1β-induced CH ferroptosis and ECM degradation, and the specific mechanism may be that it can inhibit IL-1β-induced CH ferroptosis by activating Nrf2 antioxidant system to attenuate the accumulation of intracellular ROS and lipid ROS.

Advances on the Role of Ferroptosis in Ionizing Radiation Response

Ferroptosis is an iron-dependent programmed cell death mode that is distinct from other cell death modes, and radiation is able to stimulate cellular oxidative stress and induce the production of large amounts of reactive oxygen radicals, which in turn leads to the accumulation of lipid peroxide and the onset of ferroptosis. In this review, from the perspective of the role of ferroptosis in generating a radiation response following cellular irradiation, the relationship between ferroptosis induced by ionizing radiation stress and the response to ionizing radiation is reviewed, including the roles of MAPK and Nrf2 signaling pathways in ferroptosis, resulting from the oxidative stress response to ionizing radiation, the metabolic regulatory role of the p53 gene in ferroptosis, and regulatory modes of action of iron metabolism and iron metabolism-related regulatory proteins in promoting and inhibiting ferroptosis. It provides some ideas for the follow-up research to explore the specific mechanism and regulatory network of ferroptosis in response to ionizing radiation.

M7G modification of FTH1 and pri-miR-26a regulates ferroptosis and chemotherapy resistance in osteosarcoma

Doxorubicin and platinum are widely used in the frontline treatment of osteosarcoma, but resistance to chemotherapy limits its curative effect. Here, we have identified that METTL1 mediated N7-Methyladenosine (m7G) low expressed in osteosarcoma tissues, plays a critical oncogenic role, and enhances osteosarcoma chemosensitivity in osteosarcoma. Mechanistically, AlkAniline-Seq data revealed that Ferritin heavy chain (FTH1), the main component of ferritin, which is crucial for iron homeostasis and the inhibition of lipid peroxidation, is one of the top 10 genes with the most significant change in m7G methylation sites mediated by METTL1 in human osteosarcoma cells. Interestingly, METTL1 significantly increased the expression of FTH1 at the mRNA level but was remarkably suppressed at the protein level. We then identified primary (pri)-miR-26a and pri-miR-98 in the Top 20 m7G-methylated pri-miRNAs with highly conserved species. Further results confirmed that METTL1 enhances cell ferroptosis by targeting FTH1 and primary (pri)-miR-26a, promoting their maturity by enhancing RNA stability dependent on m7G methylation. The increase of mature miR-26a-5p that resulted from METTL1 overexpression could further target FTH1 mRNA and eliminate FTH1 translation efficiency. Moreover, the reduction of FTH1 translation dramatically increases cell ferroptosis and promotes the sensitivity of osteosarcoma cells to chemotherapy drugs. Collectively, our study demonstrates the METTL1/pri-miR-26a/FTH1 axis signaling in osteosarcoma and highlights the functional importance of METTL1 and m7G methylation in the progression and chemotherapy resistance of osteosarcoma, suggesting that reprogramming RNA m7G methylation as a potential and promising strategy for osteosarcoma treatment.

Antigen processing and presentation-related signature-derived BNIP3 is a novel oncogene and immunotherapy determinant in osteosarcoma based on machine learning and in vitro validation

BACKGROUND

In recent decades, osteosarcoma has remained the most prevalent kind of malignant tumor. An important and crucial factor in immunotherapy is antigen processing and presentation (APP). The specific functions and pathogenic processes of APP in osteosarcoma have not, however, been studied.

METHODS

Patients with osteosarcoma were divided into groups using APP-related genes. Machine learning was used to further build the APP-related score. Investigated in-depth were the prognostic relevance of the score, mutation features, immunological aspects, and pharmacological prediction performance. Investigations of the prognostic utility, immunological traits, drug prediction effectiveness and immunotherapy prediction of BNIP3 were performed in-depth.

RESULTS

Investigations by cell counting kit-8, Transwell and 5-ethynyl-2-deoxyuridine (EdU) demonstrated that BNIP3 is an osteosarcoma tumor accelerator. The osteosarcoma gene BNIP3 may promote macrophage migration. The APP-related score shows potential for clinical use.

CONCLUSIONS

It was anticipated that more in vitro and in vivo studies would confirm BNIP3's tumorigenic and immunogenic processes in osteosarcoma.

Yi-qi-hua-yu-jie-du decoction induces ferroptosis in cisplatin-resistant gastric cancer via the AKT/GSK3β/NRF2/GPX4 axis

BACKGROUND

Resistance to chemotherapy in gastric cancer (GC) is a ubiquitous challenge for its treatment. Yi-qi-hua-yu-jie-du decoction (YJD), an empirical formula in Traditional Chinese Medicine (TCM), demonstrated survival-prolonging functions in patients with GC. Previous research has shown that YJD could also inhibit drug resistance in GC. However, the precise mechanisms for how YJD accomplishes this remain incompletely explained.

PURPOSE

The research aimed to identify differential metabolic characteristics in cisplatin-resistant GC and investigate whether YJD can target these differences to suppress GC drug resistance.

METHODS

Metabolomic analysis was conducted to identify metabolic disparities between cisplatin-resistant and parental GC cells, as well as metabolic modifications resulting from YJD intervention in cisplatin-resistant GC cells. The effect of YJD on ferroptosis stimulation was assessed by measuring the levels of reactive oxygen species (ROS), malondialdehyde (MDA), iron ions, the reduced glutathione (GSH) to oxidised glutathione (GSSG) ratio, and alterations in mitochondrial morphology. Western blotting and quantitative real-time polymerase chain reaction (Q-PCR) were employed to verity the mechanisms of YJD-triggered ferroptosis through GPX4 and NRF2 overexpression models, alongside the AKT activator SC79. In vivo validation was conducted using nude mouse xenograft models.

RESULTS

Cisplatin-resistant GC exhibited altered GSH/GPX4 metabolism, and ferroptosis was a significantly enriched cell death pattern with YJD treatment in cisplatin-resistant GC cells. Ferroptosis biomarkers, including ROS, MDA, iron ions, the GSH/GSSG ratio, and mitochondrial morphology, were remarkably changed with the YJD intervention. Mechanistic experiments demonstrated that YJD inhibited the phosphorylation cascade activity of the AKT/GSK3β pathway, thereby reducing NRF2 expression. The level of GPX4, a crucial enzyme involved in glutathione metabolism, was attenuated, facilitating ferroptosis induction in cisplatin-resistant GC.

CONCLUSION

The research reveals, for the first time, changes in GSH/GPX4 metabolism in cisplatin-resistant GC cells based on metabolomic analysis. YJD induced ferroptosis in cisplatin-resistant GC by inhibiting GPX4 through the AKT/GSK3β/NRF2 pathway, thus attenuating the cisplatin drug resistance in GC. Our findings identify metabolic changes in cisplatin-resistant GC and establish a theoretical framework for YJD on tackling drug resistance in GC through ferroptosis.

Ferroptosis induction via targeting metabolic alterations in triple-negative breast cancer

Triple-negative breast cancer (TNBC), the most aggressive form of breast cancer, presents severe threats to women's health. Therefore, it is critical to find novel treatment approaches. Ferroptosis, a newly identified form of programmed cell death, is marked by the buildup of lipid reactive oxygen species (ROS) and high iron concentrations. According to previous studies, ferroptosis sensitivity can be controlled by a number of metabolic events in cells, such as amino acid metabolism, iron metabolism, and lipid metabolism. Given that TNBC tumors are rich in iron and lipids, inducing ferroptosis in these tumors is a potential approach for TNBC treatment. Notably, the metabolic adaptability of cancer cells allows them to coordinate an attack on one or more metabolic pathways to initiate ferroptosis, offering a novel perspective to improve the high drug resistance and clinical therapy of TNBC. However, a clear picture of ferroptosis in TNBC still needs to be completely revealed. In this review, we provide an overview of recent advancements regarding the connection between ferroptosis and amino acid, iron, and lipid metabolism in TNBC. We also discuss the probable significance of ferroptosis as an innovative target for chemotherapy, radiotherapy, immunotherapy, nanotherapy and natural product therapy in TNBC, highlighting its therapeutic potential and application prospects.

Moving beyond cisplatin resistance: mechanisms, challenges, and prospects for overcoming recurrence in clinical cancer therapy

Cisplatin, a classical platinum-based chemotherapy agent, has been a frontline treatment for various cancers for decades. However, its effectiveness has been hindered by the development of resistance, leading to cancer relapse. Addressing this challenge is crucial for both clinical practice and research. Hence, the imperative to unravel the intricate mechanisms underpinning cisplatin resistance and to uncover novel strategies to overcome this barrier holds immense significance. Within this review, we summarized the classification of platinum agents, highlighting their roles in therapeutic landscapes. We discussed the diverse mechanisms behind cisplatin resistance, including diminished intracellular cisplatin accumulation, intracellular detoxification, DNA repair, autophagy responses, heat shock proteins, tumor microenvironment, cancer stem cells, epigenetic regulation, ferroptosis resistance, and metabolic reprogramming. Drawing from this comprehensive understanding, we offered a series of prospective solutions to surmount cisplatin resistance and consequently mitigate the specter of disease recurrence within the realm of clinical cancer therapy.

Natural compounds efficacy in complicated diabetes: A new twist impacting ferroptosis

Ferroptosis, as a way of cell death, participates in the body's normal physiological and pathological regulation. Recent studies have shown that ferroptosis may damage glucose-stimulated islets β Insulin secretion and programmed cell death of T2DM target organs are involved in the pathogenesis of T2DM and its complications. Targeting suppression of ferroptosis with specific inhibitors may provide new therapeutic opportunities for previously untreated T2DM and its target organs. Current studies suggest that natural bioactive compounds, which are abundantly available in drugs, foods, and medicinal plants for the treatment of T2DM and its target organs, have recently received significant attention for their various biological activities and minimal toxicity, and that many natural compounds appear to have a significant role in the regulation of ferroptosis in T2DM and its target organs. Therefore, this review summarized the potential treatment strategies of natural compounds as ferroptosis inhibitors to treat T2DM and its complications, providing potential lead compounds and natural phytochemical molecular nuclei for future drug research and development to intervene in ferroptosis in T2DM.

Eicosapentaenoic acid enhances the sensitivity of osteosarcoma to cisplatin by inducing ferroptosis through the DNA-PKcs/AKT/NRF2 pathway and reducing PD-L1 expression to attenuate immune evasion

Acquired drug resistance poses a significant challenge in osteosarcoma therapy. Therefore, it is necessary for us to discover and develop an alternative anti-cancer strategy. Previous studies have shown that eicosapentaenoic acid (EPA) significantly increases chemosensitivity in cancer cells. In this study, we discovered that EPA enhances the sensitivity of osteosarcoma to cisplatin (DDP). Interestingly, in addition to inhibiting growth and inducing apoptosis, EPA also enhances DDP-induced ferroptosis. Western blot analysis confirmed that EPA treatment significantly decreases the expression of DNA-dependent protein kinase catalytic subunit (DNA-PKcs), p-AKT, nuclear factor erythroid 2-related factor 2 (NRF2), and glutathione peroxidase 4 (GPX4) in cells. Knockdown of DNA-PKcs by siRNA further enhances the level of ferroptosis induced by EPA. Importantly, EPA can reverse the high expression level of programmed death ligand 1 (PD-L1) induced by DDP. ELISA and western blotting analysis revealed that EPA treatment decreases the levels of IL-6 and p-STAT3, which are increased by DDP treatment. Furthermore, a co-immunoprecipitation (co-IP) assay confirmed the interaction between DNA-PKcs and PD-L1, and knockdown of DNA-PKcs further reduces the expression of PD-L1. This data provides the first evidence that EPA suppresses the DNA-PKcs/AKT/NRF2/GPX4 pathway to enhance ferroptosis, and inhibits IL-6/STAT3 and DNA-PKcs to decrease PD-L1 expression, thereby sensitizing osteosarcoma to DDP. The combination of EPA and DDP presents an encouraging and promising anti-tumor strategy.

Amplified Ferroptosis and Apoptosis Facilitated by Differentiation Therapy Efficiently Suppress the Progression of Osteosarcoma

Osteosarcoma (OS) is the most frequent osseous neoplasm among young people aged 10-20. Currently, the leading treatment for osteosarcoma is a combination of surgery and chemotherapy. However, the mortality remains high due to chemoresistance, metastasis, and recurrence, attributing to the existence of cancer stem cells (CSCs) as reported. To target CSCs, differentiation therapy attracts increasing attention, inducing CSCs to bulk tumor cells with elevated reactive oxygen species (ROS) levels and less chemoresistance. Moreover, increasing studies have implied that ferroptosis is a promising approach to eliminating cancer cells through eliciting oxidative damage and subsequent apoptosis, effectively bypassing chemoresistance. Here, a cancer-cell-membrane-decorated biocompatible formulation (GA-Fe@CMRALi liposome) is constructed to combat OS efficiently by combining distinct differentiation and ferroptosis therapies through magnified ROS-triggered ferroptosis and apoptosis with homologous target capability to tumor sites. The combinational approach exhibited favorable therapeutic efficacy against OS in vitro and in vivo. Impressively, the potential mechanisms are revealed by mRNA sequencing. This study provides a tactical design and typical paradigm of the synergized differentiation and ferroptosis therapies to combat heterogeneous OS.

Decoding the Impact of Tumor Microenvironment in Osteosarcoma Progression and Metastasis

Osteosarcoma (OS) is a heterogeneous, highly metastatic bone malignancy in children and adolescents. Despite advancements in multimodal treatment strategies, the prognosis for patients with metastatic or recurrent disease has not improved significantly in the last four decades. OS is a highly heterogeneous tumor; its genetic background and the mechanism of oncogenesis are not well defined. Unfortunately, no effective molecular targeted therapy is currently available for this disease. Understanding osteosarcoma's tumor microenvironment (TME) has recently gained much interest among scientists hoping to provide valuable insights into tumor heterogeneity, progression, metastasis, and the identification of novel therapeutic avenues. Here, we review the current understanding of the TME of OS, including different cellular and noncellular components, their crosstalk with OS tumor cells, and their involvement in tumor progression and metastasis. We also highlight past/current clinical trials targeting the TME of OS for effective therapies and potential future therapeutic strategies with negligible adverse effects.

Targeting Ferroptosis in Bone-Related Diseases: Facts and Perspectives

Ferroptosis is a new cell fate decision discovered in recent years. Unlike apoptosis, autophagy or pyroptosis, ferroptosis is characterized by iron-dependent lipid peroxidation and mitochondrial morphological changes. Ferroptosis is involved in a variety of physiological and pathological processes. Since its discovery, ferroptosis has been increasingly studied concerning bone-related diseases. In this review, we focus on the latest research progress and prospects, summarize the regulatory mechanisms of ferroptosis, and discuss the role of ferroptosis in the pathogenesis of bone-related diseases, such as osteoporosis (OP), osteoarthritis (OA), rheumatoid arthritis (RA), and osteosarcoma (OS), as well as its therapeutic potential.

Butyrate enhances erastin-induced ferroptosis of osteosarcoma cells via regulating ATF3/SLC7A11 pathway

Osteosarcoma (OS) is a highly fatal bone tumor characterized by high degree of malignancy and early lung metastasis. Traditional chemotherapy fails in improving the efficacy and survival rate of patients with OS. Butyrate (NaBu) has been reported as a new antitumor drug for inhibiting proliferation and inducing apoptosis in various cancer cells. However, the effect of NaBu on the ferroptosis of OS is still unknown. This study aimed to investigate whether NaBu promotes erastin-induced ferroptosis in OS cells and to uncover the underlying mechanism. Here, we found that NaBu significantly enhanced erastin-induced ferroptosis in vitro and in vivo. Compared with the group that erastin used alonely, pre-treating with NaBu exacerbated erastin-meditated GSH depletion, lipid peroxidation, and mitochondrial morphologic changes in OS cells. In a subcutaneous OS model, NaBu combined with erastin significantly reduced tumor growth and increased the levels of 4-HNE. Mechanistically, NaBu downregulated SLC7A11 transcription via regulating ATF3 expression. Overexpression of ATF3 facilitated erastin to induce ferroptosis, while ATF3 knockdown attenuated NaBu-induced ferroptosis sensitivity. In conclusion, our findings revealed a previously unidentified role of NaBu in erastin-induced ferroptosis by regulating SLC7A11, suggesting that NaBu may be a potential therapeutic agent for OS treatment.

Targeting ferroptosis opens new avenues for the development of novel therapeutics

Ferroptosis is an iron-dependent form of regulated cell death with distinct characteristics, including altered iron homeostasis, reduced defense against oxidative stress, and abnormal lipid peroxidation. Recent studies have provided compelling evidence supporting the notion that ferroptosis plays a key pathogenic role in many diseases such as various cancer types, neurodegenerative disease, diseases involving tissue and/or organ injury, and inflammatory and infectious diseases. Although the precise regulatory networks that underlie ferroptosis are largely unknown, particularly with respect to the initiation and progression of various diseases, ferroptosis is recognized as a bona fide target for the further development of treatment and prevention strategies. Over the past decade, considerable progress has been made in developing pharmacological agonists and antagonists for the treatment of these ferroptosis-related conditions. Here, we provide a detailed overview of our current knowledge regarding ferroptosis, its pathological roles, and its regulation during disease progression. Focusing on the use of chemical tools that target ferroptosis in preclinical studies, we also summarize recent advances in targeting ferroptosis across the growing spectrum of ferroptosis-associated pathogenic conditions. Finally, we discuss new challenges and opportunities for targeting ferroptosis as a potential strategy for treating ferroptosis-related diseases.

Gambogenic acid induces cell death in human osteosarcoma through altering iron metabolism, disturbing the redox balance, and activating the P53 signaling pathway

Osteosarcoma (OS) is the most common primary bone malignancy in children and adolescents with extremely poor prognosis. Gambogenic acid (GNA), one of the major bioactive ingredients isolated from Gamboge, has been shown to possess a multipotent antitumor effect, its activity on OS remains unclear yet. In this study, we found that GNA could trigger multiple cell death modalities, including ferroptosis and apoptosis in human OS cells, reduce the cell viability, inhibit the proliferation and invasiveness. Furthermore, GNA provoked oxidative stress leading to GSH depletion-inducing ROS generation and lipid peroxidation, altered iron metabolism represented by the induction of labile iron, mitochondrial membrane potential decreased, mitochondrial morphological changed, decreased the cell viability. In addition, ferroptosis inhibitors (Fer-1) and apoptosis inhibitors (NAC) can partially reversed GNA' s effects on OS cells. Further investigation showed that GNA augmented the expression of P53, bax, caspase 3 and caspase 9 and decreased the expression of Bcl-2, SLC7A11 and glutathione peroxidase-4 (GPX4). In vivo, GNA was showed to delay tumor growth significantly in axenograft osteosarcoma mouse model. In conclusion, this study reveals that GNA simultaneously triggers ferroptosis and apoptosis in human OS cells by inducing oxidative stress via the P53/SLC7A11/GPX4 axis.

Loss of NSUN6 inhibits osteosarcoma progression by downregulating EEF1A2 expression and activation of Akt/mTOR signaling pathway via m5C methylation

As an important 5-methylcytidine (m5C) methyltransferase, NOP2/Sun RNA methyltransferase family member 6 (NSUN6) has been reported to play an important role in the progression of several diseases. However, the role of NSUN6 in the progression of osteosarcoma (OS) remains unclear. This study aimed to identify the role of NSUN6 in the progression of OS and clarify the potential molecular mechanism. The present study discovered that NSUN6 was upregulated in OS and a higher NSUN6 expression was a strong indicator for poorer prognosis of patients with OS. In addition, the loss of NSUN6 led to reduced proliferation, migration and invasion of OS cells. Through bioinformatics analysis, RNA immunoprecipitation (RIP) and methylated RIP assays, eukaryotic elongation factor 1 α-2 (EEF1A2) was identified and validated as a potential target of NSUN6 in OS. Mechanistically, the expression of EEF1A2 was significantly suppressed following NSUN6 knockdown due to reduced EEF1A2 mRNA stability in an m5C-dependent manner. Meanwhile, NSUN6 deficiency inhibited m5C-dependent activation of Akt/mTOR signaling pathway. In addition, genetic overexpression of EEF1A2 or pharmacological activation of the Akt signaling pathway counteracted the suppressive effects of NSUN6 deficiency on the proliferation, invasion and migration of OS cells. The current findings suggested that NSUN6 may serve as a potential therapeutic target for OS treatment.

The Regulation of Ferroptosis by Noncoding RNAs

As a novel form of regulated cell death, ferroptosis is characterized by intracellular iron and lipid peroxide accumulation, which is different from other regulated cell death forms morphologically, biochemically, and immunologically. Ferroptosis is regulated by iron metabolism, lipid metabolism, and antioxidant defense systems as well as various transcription factors and related signal pathways. Emerging evidence has highlighted that ferroptosis is associated with many physiological and pathological processes, including cancer, neurodegeneration diseases, cardiovascular diseases, and ischemia/reperfusion injury. Noncoding RNAs are a group of functional RNA molecules that are not translated into proteins, which can regulate gene expression in various manners. An increasing number of studies have shown that noncoding RNAs, especially miRNAs, lncRNAs, and circRNAs, can interfere with the progression of ferroptosis by modulating ferroptosis-related genes or proteins directly or indirectly. In this review, we summarize the basic mechanisms and regulations of ferroptosis and focus on the recent studies on the mechanism for different types of ncRNAs to regulate ferroptosis in different physiological and pathological conditions, which will deepen our understanding of ferroptosis regulation by noncoding RNAs and provide new insights into employing noncoding RNAs in ferroptosis-associated therapeutic strategies.

MAT2A inhibits the ferroptosis in osteosarcoma progression regulated by miR-26b-5p

Osteosarcoma (OS) is the most frequent primary malignant bone tumor. Ferroptosis, a form of regulated cell death, is a key tumor suppression mechanism. Although methionine adenosyltransferase II alpha (MAT2A) has been reported to inhibit several tumor cells, it is unclear whether inhibition of MAT2A in OS cells can reduce ferroptosis. CCK-8, flow cytometry, and Transwell assays were performed to evaluate cell viability, cell apoptosis/cycle, and cell migration, respectively. The levels of ferrous iron and glutathione (GSH) levels in cells were measured to evaluate the degree of cell ferroptosis. Western blot analysis was performed to detect protein levels of MAT2A, p-STAT3 (Ser727)/STAT3, and solute carrier family 7 member 11 (SLC7A11) in OS cells. MAT2A was significantly upregulated in OS specimens and high MAT2A expression was associated with a poorer prognosis in OS patients. shRNA targeting MAT2A significantly increased OS cell apoptosis, triggered cell cycle arrest in the G2 phase, and attenuated migration ability in vitro. MAT2A depletion dramatically inhibited tumor progression of OS in vivo. Overexpression of MAT2A rescued the tumor inhibition caused by miR-26b-5p. MAT2A knockdown promoted OS cell ferroptosis. miR-26b-5p/MAT2A regulates tumor malignant progression and OS cell ferroptosis by controlling p-STAT3 and SLC7A11 expressions. Taken together, our study displayed that miR-26b-5p/MAT2A triggers ferroptosis in OS cells by increasing intracellular ferrous iron levels and inhibiting the STAT3/SLC7A11 axis. Our results reveal a MAT2A-mediated ferroptosis defense mechanism used by OS cells and propose a potential ferroptosis-inducing strategy for the treatment of OS patients.

The role of ferroptosis in intervertebral disc degeneration

Nucleus pulposus, annulus fibrosus, and cartilage endplate constitute an avascular intervertebral disc (IVD), which is crucial for spinal and intervertebral joint mobility. As one of the most widespread health issues worldwide, intervertebral disc degeneration (IVDD) is recognized as a key contributor to back and neck discomfort. A number of degenerative disorders have a strong correlation with ferroptosis, a recently identified novel regulated cell death (RCD) characterized by an iron-dependent mechanism and a buildup of lipid reactive oxygen species (ROS). There is growing interest in the part ferroptosis plays in IVDD pathophysiology. Inhibiting ferroptosis has been shown to control IVDD development. Several studies have demonstrated that in TBHP-induced oxidative stress models, changes in ferroptosis marker protein levels and increased lipid peroxidation lead to the degeneration of intervertebral disc cells, which subsequently aggravates IVDD. Similarly, IVDD is significantly relieved with the use of ferroptosis inhibitors. The purpose of this review was threefold: 1) to discuss the occurrence of ferroptosis in IVDD; 2) to understand the mechanism of ferroptosis and its role in IVDD pathophysiology; and 3) to investigate the feasibility and prospect of ferroptosis in IVDD treatment.

Exosome-mediated miR-144-3p promotes ferroptosis to inhibit osteosarcoma proliferation, migration, and invasion through regulating ZEB1

BACKGROUND

Osteosarcoma (OS) is the most prevalent orthopedic malignancy with a dismal prognosis. The high iron absorption rate in OS cells of patients suggests that ferroptosis may be related to the progression of OS, but its potential molecular regulatory role is still unclear. Based on the ability to couple with exosomes for targeted delivery of signals, exosome-derived micro ribonucleic acids (miRNAs) can potentially serve as diagnostic biomarkers for OS.

METHODS

We identified ferroptosis-related miRNAs and messenger ribonucleic acids(mRNAs) in OS using bioinformatics analysis and performed survival analysis. Then we measured miRNA expression levels through exosome microarray sequencing, and used RT-qPCR and IHC to verify the expression level of miR-144-3p and ZEB1. Stable gene expression cell lines were fabricated for in vitro experiments. Cell viability, migration and invasion were determined by CCK-8 and transwell experiment. Use the corresponding reagent kit to detect GSH/GSSG ratio, Fe²⁺ level, MDA level and ROS level, and measure the expression levels of GPX4, ACSL4 and xCT through RT-qPCR and WB. We also constructed nude mice model for in vivo experiments. Finally, the stability of the miRNA/mRNA axis was verified through functional rescue experiments.

RESULTS

Low expression of miR-144-3p and high expression of ZEB1 in OS cell lines and tissues was observed. Overexpression of miR-144-3p can promote ferroptosis, reduce the survival ability of OS cells, and prevent the progression of OS. In addition, overexpression of miR-144-3p can downregulate the expression of ZEB1 in cell lines and nude mice. Knockdown of miR-144-3p has the opposite effect. The functional rescue experiment validated that miR-144-3p can regulate downstream ZEB1, and participates in the occurrence and development of OS by interfering with redox homeostasis and iron metabolism.

CONCLUSIONS

MiR-144-3p can induce the occurrence of ferroptosis by negatively regulating the expression of ZEB1, thereby inhibiting the proliferation, migration, and invasion of OS cells.

Isoorientin reverses lung cancer drug resistance by promoting ferroptosis via the SIRT6/Nrf2/GPX4 signaling pathway

Cisplatin, or DDP, is a highly successful and well-known chemotherapy drug used to treat cancer. Acquired resistance to chemotherapy is a major clinical concern, yet the mechanisms of this resistance are still unknown. Ferroptosis is a type of cell death distinct from other forms, fueled by a buildup of iron-associated lipid reactive oxygen species (ROS). Gaining insight into the process of ferroptosis could lead to novel treatments for overcoming cancer resistance. In this study, the combination of isoorientin (IO) and DDP treatment resulted in a significant decrease in the viability of drug-resistant cells, a substantial increase in intracellular iron, malondialdehyde (MDA) and ROS concentrations, a notable decrease in glutathione concentration, and the occurrence of ferroptosis in cells, as revealed by in vitro and in vivo experiments. Additionally, there was a decrease in the expression of nuclear factor-erythroid factor 2-related factor 2 (Nrf2), glutathione peroxidase 4 (GPX4), and sirtuin 6 (SIRT6) proteins, and an increase in cellular ferroptosis. Isoorientin acts as a mediator to regulate cellular ferroptosis and reverse drug resistance in lung cancer cells by controlling the SIRT6/Nrf2/GPX4 signaling pathway. The findings of this study suggest that IO can promote ferroptosis and reverse drug resistance in lung cancer through the SIRT6/Nrf2/GPX4 signaling pathway, thus offering a theoretical basis for its potential clinical application.

Targeting Nrf2 for ferroptosis-based therapy: Implications for overcoming ferroptosis evasion and therapy resistance in cancer

Ferroptosis is a newly discovered form of programmed cell death caused by redox-active iron-mediated lipid peroxidation. Ferroptosis exhibits a unique morphological phenotype resulting from oxidative damage to membrane lipids. Ferroptosis induction has been shown to be effective in treating human cancers that rely on lipid peroxidation repair pathways. Nuclear factor erythroid 2-related factor 2 (Nrf2) can control the regulatory pathways of ferroptosis, which involve genes associated with glutathione biosynthesis, antioxidant responses, and lipid and iron metabolism. Resistant cancer cells often utilize Nrf2 stabilization by Keap1 inactivation or other somatic alterations in the genes from the Nrf2 pathway, which can confer resistance to ferroptosis induction and other therapies. However, pharmacological inactivation of the Nrf2 pathway can sensitize cancer cells to ferroptosis induction. Inducing lipid peroxidation and ferroptosis through regulating the Nrf2 pathway is a promising strategy for enhancing the anticancer effects of chemotherapy and radiation therapy in therapy-resistant human cancers. Despite promising preliminary studies, clinical trials in human cancer therapy have not yet been realized. A deeper understanding of their exact processes and efficacies in various cancers remains unsolved. Therefore, this article aims to summarize the regulatory mechanisms of ferroptosis, their modulation by Nrf2, and the potential of targeting Nrf2 for ferroptosis-based cancer therapy.

Cold plasma and inhibition of STAT3 selectively target tumorigenicity in osteosarcoma

Osteosarcoma (OS) is a malignant type of bone cancer that arises in periods of increased bone formation. Curative strategies for these types of tumors have remained essentially unchanged for decades and the overall survival for most advanced cases is still dismally low. This is in part due to the existence of drug resistant Cancer Stem Cells (CSC) with progenitor properties that are responsible for tumor relapse and metastasis. In the quest for therapeutic alternatives for OS, Cold Atmospheric Plasmas and Plasma-Treated Liquids (PTL) have come to the limelight as a source of Reactive Oxygen and Nitrogen Species displaying selectivity towards a variety of cancer cell lines. However, their effects on CSC subpopulations and in vivo tumor growth have been barely studied to date. By employing bioengineered 3D tumor models and in vivo assays, here we show that low doses of PTL increase the levels of pro-stemness factors and the self-renewal ability of OS cells, coupled to an enhanced in vivo tumor growth potential. This could have critical implications to the field. By proposing a combined treatment, our results demonstrate that the deleterious pro-stemness signals mediated by PTL can be abrogated when this is combined with the STAT3 inhibitor S3I-201, resulting in a strong suppression of in vivo tumor growth. Overall, our study unveils an undesirable stem cell-promoting function of PTL in cancer and supports the use of combinatorial strategies with STAT3 inhibitors as an efficient treatment for OS avoiding critical side effects. We anticipate our work to be a starting point for wider studies using relevant 3D tumor models to evaluate the effects of plasma-based therapies on tumor subpopulations of different cancer types. Furthermore, combination with STAT3 inhibition or other suitable cancer type-specific targets can be relevant to consolidate the development of the field.

Enhancing Vulnerability of Afatinib using Erastin via xCT-mediated ROS/P38MAPK Signaling Feedback Loop in Gastric Cancer Cells

Ferroptosis, being classified as a form of regulated cell death, was driven by the oxidative injury induced by lipid peroxidation(LPO). Recently, ferroptosis has been confirmed to exert a critical effect in the pathogenesis and treatment of various tumors, including gastric cancer (GC). Erastin, as a frequently used ferroptosis inducer, caused ferroptosis by downregulating the xCT expression resulting in increasing reactive oxygen species (ROS) and aggravating the LPO. However, the mechanisms of Erastin in ferroptosis regulation, especially in GC, remain largely elusive. This work firstly demonstrated that Erastin inhibited cell growth and promoted apoptosis and ferroptosis in AGS and BGC823 cells. Then, based on Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of Erastin-related targets screened by using PharmMapper Web, the P38MAPK signaling was explored and validated in AGS and BGC-823 cells. Besides, the Fer-1 and p38 inhibitor were performed to investigate the mechanisms of ferroptosis induced by Erastin in depth. This work revealed a feedback mode among xCT, ROS and the P38MAPK pathway, which affected each other. It meant that Erastin regulated ferroptosis through the xCT-mediated ROS/P38MAPK signaling feedback loop. In addition, it was noticed that in co-operation with Erastin, the cytotoxic effects of Afatinib on cells were aggravated by further strengthening ferroptosis with activation of the P38MAPK pathway. In summary, those works provided evidence that Erastin plays an important role in increasing the cytotoxic effect on GC cells treated with Afitinib. Furthermore, the Erastin-induced ferroptosis via the xCT-mediated ROS/P38MAPK pathway feedback loop provides new strategies for GC comprehensive treatment.