Tagitinin C induces ferroptosis through PERK-Nrf2-HO-1 signaling pathway in colorectal cancer cells

Targeting ABCB6 with nitidine chloride inhibits PI3K/AKT signaling pathway to promote ferroptosis in multiple myeloma

Since multiple myeloma (MM) remains a cureless malignancy of plasma cells to date, it becomes imperative to develop novel drugs and therapeutic targets for MM. We screened a small molecule library comprising 3633 natural product drugs, which demonstrated that Nitidine Chloride (NC), an extract from traditional Chinese medicine Zanthoxylum nitidum. We used Surface Plasmon Resonance-High Performance Liquid Chromatography-Protein Mass Spectrometry (SPR-HPLC-MS), Cellular Thermal Shift Assay (CETSA), molecular docking, and SPR assay to identify the potential targets of NC, in which ABCB6 was the unique target of NC. The effects of ABCB6 on cellular proliferation and drug resistance were determined by CCK8, western blot, flow cytometry, site-mutation cells, transmission electron microscopy, immunohistochemistry staining and xenograft model in vitro and in vivo. NC induced MM cell death by promoting ferroptosis. ABCB6 is the direct target of NC. ABCB6 expression was increased in MM samples compared to normal controls, which was significantly associated with MM relapse and poor outcomes. VGSK was the inferred binding epitope of NC on the ABCB6 protein. In the ABCB6-mutated MM cells, NC did not display cancer resistance, implying the vital role of ABCB6 in NC's bioactivity. Moreover, the silencing of ABCB6 significantly inhibited MM cell growth. Mechanistically, the direct binding of NC to ABCB6 suppressed PI3K/AKT signaling pathway to promote ferroptosis. In conclusion, ABCB6 can be a potential therapeutic target and prognostic biomarker in MM, while NC can be considered a novel drug for MM treatment.

Cytotoxic C-20 non-oxygenated ent-kaurane diterpenoids from Isodon wardii

Twenty new ent-kaurane diterpenoids, wardiisins A-T (1-20), along with two previously undescribed artefactual compounds (21 and 22) and twelve known analogues (23-34), were isolated from the aerial part of Isodon wardii. Their structures were elucidated by comprehensive analysis of spectroscopic data and single-crystal X-ray diffraction, and most of them were found to bear unusual C-12 oxygenation. Compounds 4, 7, 8, 19, 20, 21 exhibited remarkable cytotoxicity against the cancer cell lines HL-60, SMMC-7721, A-549, MDA-MB-231, and SW480, with IC₅₀ values ranging from 0.3 to 5.2 μM. Moreover, 7 was found to induce G2/M cell cycle arrest and promote apoptosis in SW480 cell lines.

Trigonochinene E promotes lysosomal biogenesis and enhances autophagy via TFEB/TFE3 in human degenerative NP cells against oxidative stress

BACKGROUND

Macroautophagy (henceforth autophagy) is the major form of autophagy, which delivers intracellular cargo to lysosomes for degradation. Considerable research has revealed that the impairment of lysosomal biogenesis and autophagic flux exacerbates the development of autophagy-related diseases. Therefore, reparative medicines restoring lysosomal biogenesis and autophagic flux in cells may have therapeutic potential against the increasing prevalence of these diseases.

PURPOSE

The aim of the present study was thus to explore the effect of trigonochinene E (TE), an aromatic tetranorditerpene isolated from Trigonostemon flavidus, on lysosomal biogenesis and autophagy and to elucidate the potential underlying mechanism.

METHODS

Four human cell lines, HepG2, nucleus pulposus (NP), HeLa and HEK293 cells were applied in this study. The cytotoxicity of TE was evaluated by MTT assay. Lysosomal biogenesis and autophagic flux induced by 40 μM TE were analyzed using gene transfer techniques, western blotting, real-time PCR and confocal microscopy. Immunofluorescence, immunoblotting and pharmacological inhibitors/activators were applied to determine the changes in the protein expression levels in mTOR, PKC, PERK, and IRE1α signaling pathways.

RESULTS

Our results showed that TE promotes lysosomal biogenesis and autophagic flux by activating the transcription factors of lysosomes, transcription factor EB (TFEB) and transcription factor E3 (TFE3). Mechanistically, TE induces TFEB and TFE3 nuclear translocation through an mTOR/PKC/ROS-independent and endoplasmic reticulum (ER) stress-mediated pathway. The PERK and IRE1α branches of ER stress are crucial for TE-induced autophagy and lysosomal biogenesis. Whereas TE activated PERK, which mediated calcineurin dephosphorylation of TFEB/TFE3, IRE1α was activated and led to inactivation of STAT3, which further enhanced autophagy and lysosomal biogenesis. Functionally, knockdown of TFEB or TFE3 impairs TE-induced lysosomal biogenesis and autophagic flux. Furthermore, TE-induced autophagy protects NP cells from oxidative stress to ameliorate intervertebral disc degeneration (IVDD).

CONCLUSIONS

Here, our study showed that TE can induce TFEB/TFE3-dependent lysosomal biogenesis and autophagy via the PERK-calcineurin axis and IRE1α-STAT3 axis. Unlike other agents regulating lysosomal biogenesis and autophagy, TE showed limited cytotoxicity, thereby providing a new direction for therapeutic opportunities to use TE to treat diseases with impaired autophagy-lysosomal pathways, including IVDD.

Bioinformatics Analysis of Molecular Interactions between Endoplasmic Reticulum Stress and Ferroptosis under Stress Exposure

Stress has become a universal biological phenomenon in the body, which leads to pathophysiological changes. However, the molecular network interactions between endoplasmic reticulum (ER) stress and ferroptosis under stressful conditions are not clear. For this purpose, we screened the gene expression profile of GSE173795 for intersection with ferroptosis genes and screened 68 differentially expressed genes (DEGs) (63 up-regulated, 5 down-regulated), mainly related to lipid and atherosclerosis, autophagy-animal, mitophagy-animal, focal adhesion, DNA replication, proteasome, oocyte meiosis, toll-like receptor signaling pathway, cell cycle, etc. Immune infiltration analysis revealed that stress resulted in decreased B cells memory, T cells CD8 and T cells CD4 memory resting, monocytes, macrophages M2, and increased B cells naive, T cells follicular helper, and macrophages M1. 19 core-DEGs (ASNS, TRIB3, ATF4, EIF2S1, CEBPG, RELA, HSPA5, DDIT3, STAT3, MAP3K5, HIF1A, HNF4A, MAPK14, HMOX1, CDKN1A, KRAS, SP1, SIRT1, EGFR) were screened, all of which were up-regulated DEGs. These biological processes and pathways were mainly involved in responding to ER stress, lipid and atherosclerosis, cellular response to stress, cellular response to chemical stress, and regulation of DNA-templated transcription in response to stress, etc. Spearman analysis did not find MAPK14 to be significantly associated with immune cells. Other core-DEGs were associated with immune cells, including B cells naive, T cells follicular helper, and monocytes. Based on core-DEGs, 283 miRNAs were predicted. Among the 22 miRNAs with highly cross-linked DEGs, 11 had upstream lncRNA, mainly targeting STAT3, SP1, CDKN1A, and SIRT1, and a total of 39 lncRNA were obtained. 85 potential drugs targeting 11 core-DEGs were identified and were expected to be potential immunotherapeutic agents for stress injury. Our experiments also confirmed that Liproxstatin-1 alleviates common cross-linked proteins between ER stress and ferroptosis. In conclusion, our study explored the molecular mechanisms and network interactions among stress-ER stress-ferroptosis from a novel perspective, which provides new research ideas for studying stressful injury.

Ferroptosis in gastrointestinal cancer: From mechanisms to implications

Ferroptosis is a form of regulated cell death that is initiated by excessive lipid peroxidation that results in plasma membrane damage and the release of damage-associated molecular patterns. In recent years, ferroptosis has gained significant attention in cancer research due to its unique mechanism compared to other forms of regulated cell death, especially caspase-dependent apoptotic cell death. Gastrointestinal (GI) cancer encompasses malignancies that arise in the digestive tract, including the stomach, intestines, pancreas, colon, liver, rectum, anus, and biliary system. These cancers are a global health concern, with high incidence and mortality rates. Despite advances in medical treatments, drug resistance caused by defects in apoptotic pathways remains a persistent challenge in the management of GI cancer. Hence, exploring the role of ferroptosis in GI cancers may lead to more efficacious treatment strategies. In this review, we provide a comprehensive overview of the core mechanism of ferroptosis and discuss its function, regulation, and implications in the context of GI cancers.

Ferroptosis open a new door for colorectal cancer treatment

Colorectal cancer (CRC) is the third highest incidence and the second highest mortality malignant tumor in the world. The etiology and pathogenesis of CRC are complex. Due to the long course of the disease and no obvious early symptoms, most patients are diagnosed as middle and late stages. CRC is prone to metastasis, most commonly liver metastasis, which is one of the leading causes of death in CRC patients. Ferroptosis is a newly discovered cell death form with iron dependence, which is driven by excessive lipid peroxides on the cell membrane. It is different from other form of programmed cell death in morphology and mechanism, such as apoptosis, pyroptosis and necroptosis. Numerous studies have shown that ferroptosis may play an important role in the development of CRC. For advanced or metastatic CRC, ferroptosis promises to open a new door in the setting of poor response to chemotherapy and targeted therapy. This mini review focuses on the pathogenesis of CRC, the mechanism of ferroptosis and the research status of ferroptosis in CRC treatment. The potential association between ferroptosis and CRC and some challenges are discussed.

Molecular Mechanisms of Nemorosone-Induced Ferroptosis in Cancer Cells

Ferroptosis is an iron-dependent cell death-driven by excessive peroxidation of polyunsaturated fatty acids (PUFAs) of membranes. A growing body of evidence suggests the induction of ferroptosis as a cutting-edge strategy in cancer treatment research. Despite the essential role of mitochondria in cellular metabolism, bioenergetics, and cell death, their function in ferroptosis is still poorly understood. Recently, mitochondria were elucidated as an important component in cysteine-deprivation-induced (CDI) ferroptosis, which provides novel targets in the search for new ferroptosis-inducing compounds (FINs). Here, we identified the natural mitochondrial uncoupler nemorosone as a ferroptosis inducer in cancer cells. Interestingly, nemorosone triggers ferroptosis by a double-edged mechanism. In addition to decreasing the glutathione (GSH) levels by blocking the System xc cystine/glutamate antiporter (SLC7A11), nemorosone increases the intracellular labile Fe²⁺ pool via heme oxygenase-1 (HMOX1) induction. Interestingly, a structural variant of nemorosone (O-methylated nemorosone), having lost the capacity to uncouple mitochondrial respiration, does not trigger cell death anymore, suggesting that the mitochondrial bioenergetic disruption via mitochondrial uncoupling is necessary for nemorosone-induced ferroptosis. Our results open novel opportunities for cancer cell killing by mitochondrial uncoupling-induced ferroptosis.

Ibrutinib facilitates the sensitivity of colorectal cancer cells to ferroptosis through BTK/NRF2 pathway

Ibrutinib is a drug that inhibits the protein Burton's tyrosine kinase and thereby the nuclear translocation of Nrf2, which played a key role in mediating the activation of antioxidants during stress conditions and ferroptosis resistance. This study aimed to identify the effect of Ibrutinib and ferroptosis inducer on colorectal cancer (CRC) treatment and its underlying mechanism. In our study, we found the upregulation of Nrf2 was correlated with CRC progression and antioxidant proteins. Ibrutinib sensitized CRC to ferroptosis inducers, suggested by further reduced CRC cell viability, proliferation and decreased antioxidant protein levels in CRC cells after combination treatment of Ibrutinib and RSL3 or Ibrutinib and Erastin both in vivo and in vitro. Knockout of Nrf2 diminished the regulatory effect of Ibrutinib on CRC sensitivity to ferroptosis inducers. Altogether, this study demonstrated that Ibrutinib increases the sensitivity of CRC cell to ferroptosis inducers by inhibiting Nrf2.

ALKBH5 decreases SLC7A11 expression by erasing m6A modification and promotes the ferroptosis of colorectal cancer cells

BACKGROUND

Colorectal cancer (CRC) is the major subtype of gastrointestinal malignancy and involves cancer-related genes and signaling pathways to regulate ferroptosis. The present study was conducted to analyze the role of alkB homolog 5 (ALKBH5) in the ferroptosis of CRC cells and provide novel targets for CRC treatment.

METHODS

The transcriptional and protein levels of ALKBH5 and solute carrier family 7 members 11 (SLC7A11) in tissues and cells were determined by qRT-PCR and Western blot assay. HCT116 and SW620 cells were transfected with ALKBH5 overexpression vectors to determine cell viability and levels of reactive oxygen species (ROS), Fe⁺, glutathione, and glutathione peroxidase 4 using cell counting kit-8, colony formation, fluorescence probe, assay kits, and Western blot assay. The N6-methyladenosine (m6A) level and the enrichment of m6A on SLC7A11 mRNA were measured by m6A quantitative analysis and m6A methylated RNA immunoprecipitation-qPCR, and the mRNA stability was determined after actinomycin D treatment. CRC cells were treated with the combination of SLC7A11 and ALKBH5 overexpression vectors to confirm the mechanism. Nude mice were subcutaneously injected with CRC cells overexpressing ALKBH5.

RESULTS

ALKBH5 was downregulated in CRC and ALKBH5 overexpression promoted ROS release and ferroptosis. ALKBH5 erased the m6A modification on SLC7A11 mRNA to reduce the mRNA stability of SLC7A11, further reducing SLC7A11 expression. SLC7A11 overexpression reversed the promotive role of ALKBH5 overexpression in ferroptosis. ALKBH5 upregulation mitigated tumor growth in vivo.

CONCLUSIONS

ALKBH5 reduced SLC7A11 transcription by erasing m6A modification, thus promoting the ferroptosis of CRC cells.

Role of ferroptosis in colorectal cancer

Colorectal cancer (CRC) is the second deadliest cancer and the third-most common malignancy in the world. Surgery, chemotherapy, and targeted therapy have been widely used to treat CRC, but some patients still develop resistance to these treatments. Ferroptosis is a novel non-apoptotic form of cell death. It is an iron-dependent non-apoptotic cell death characterized by the accumulation of lipid reactive oxygen species and has been suggested to play a role in reversing resistance to anticancer drugs. This review summarizes recent advances in the prognostic role of ferroptosis in CRC and the mechanism of action in CRC.

Establishment and external verification of an oxidative stress-related gene signature to predict clinical outcomes and therapeutic responses of colorectal cancer

Objective: Accumulated evidence highlights the biological significance of oxidative stress in tumorigenicity and progression of colorectal cancer (CRC). Our study aimed to establish a reliable oxidative stress-related signature to predict patients' clinical outcomes and therapeutic responses. Methods: Transcriptome profiles and clinical features of CRC patients were retrospectively analyzed from public datasets. LASSO analysis was used to construct an oxidative stress-related signature to predict overall survival, disease-free survival, disease-specific survival, and progression-free survival. Additionally, antitumor immunity, drug sensitivity, signaling pathways, and molecular subtypes were analyzed between different risk subsets through TIP, CIBERSORT, oncoPredict, etc. approaches. The genes in the signature were experimentally verified in the human colorectal mucosal cell line (FHC) along with CRC cell lines (SW-480 and HCT-116) through RT-qPCR or Western blot. Results: An oxidative stress-related signature was established, composed of ACOX1, CPT2, NAT2, NRG1, PPARGC1A, CDKN2A, CRYAB, NGFR, and UCN. The signature displayed an excellent capacity for survival prediction and was linked to worse clinicopathological features. Moreover, the signature correlated with antitumor immunity, drug sensitivity, and CRC-related pathways. Among molecular subtypes, the CSC subtype had the highest risk score. Experiments demonstrated that CDKN2A and UCN were up-regulated and ACOX1, CPT2, NAT2, NRG1, PPARGC1A, CRYAB, and NGFR were down-regulated in CRC than normal cells. In H₂O₂-induced CRC cells, their expression was notably altered. Conclusion: Altogether, our findings constructed an oxidative stress-related signature that can predict survival outcomes and therapeutic response in CRC patients, thus potentially assisting prognosis prediction and adjuvant therapy decisions.

Molecular mechanisms of ferroptosis and relevance to inflammation

INTRODUCTION

Inflammation is a defensive response of the organism to irritation which is manifested by redness, swelling, heat, pain and dysfunction. The inflammatory response underlies the role of various diseases. Ferroptosis, a unique modality of cell death, driven by iron-dependent lipid peroxidation, is regulated by multifarious cellular metabolic pathways, including redox homeostasis, iron processing and metabolism of lipids, as well as various signaling pathways associated with diseases. A growing body of evidence suggests that ferroptosis is involved in inflammatory response, and targeting ferroptosis has great prospects in preventing and treating inflammatory diseases.

MATERIALS AND METHODS

Relevant literatures on ferroptosis, inflammation, inflammatory factors and inflammatory diseases published from January 1, 2010 to now were searched in PubMed database.

CONCLUSION

In this review, we summarize the regulatory mechanisms associated with ferroptosis, discuss the interaction between ferroptosis and inflammation, the role of mitochondria in inflammatory ferroptosis, and the role of targeting ferroptosis in inflammatory diseases. As more and more studies have confirmed the relationship between ferroptosis and inflammation in a wide range of organ damage and degeneration, drug induction and inhibition of ferroptosis has great potential in the treatment of immune and inflammatory diseases.

Mechanism and application of ferroptosis in colorectal cancer

Colorectal cancer (CRC) is the third most common malignant tumor in the world. CRC has high morbidity and mortality rates and it is a serious threat to human health. Ferroptosis is a unique form of iron-dependent oxidative cell death that is usually accompanied by iron accumulation and lipid peroxidation. Ferroptosis has attracted worldwide attention since it was first proposed. It plays an important role in the development of a variety of diseases, such as tumors, ischemia/reperfusion injury, nervous system diseases, and kidney damage, and it may serve as a new therapeutic target. This article reviews the mechanism of ferroptosis and the possibility to target ferroptosis pathways in CRC, providing new ideas for the diagnosis and treatment of CRC.

Sesquiterpenoids from Tithonia diversifolia (Hemsl.) A. Gray induce apoptosis and inhibit the cell cycle progression of acute myeloid leukemia cells

Three sesquiterpene lactones (1-3) were isolated from the aerial part of Tithonia diversifolia (Hemsl.) A. Gray grown in the Hoa Binh province in Viet Nam. The structures of these three sesquiterpene lactones were identified as tagitinin A (1), 1β-hydroxytirotundin 3-O-methyl ether (2), and tagitinin C (3) by analyzing spectroscopic data. For the first time, compound 2 was isolated from T. diversifolia growing in Viet Nam. Furthermore, contrary to existing literature, we determined that compound 1 was the major isolate. Compounds 1 and 3 significantly decreased numbers of acute myeloid leukemia OCI-AML3 cells by promoting apoptosis and causing cell cycle arrest at G0/G1 phase at concentrations as low as 2.5 μg/mL (compound 1) and 0.25 μg/mL (compound 3). Additionally, all three compounds showed cytotoxic activity against five human cancer cell lines (A549, T24, Huh-7, 8505, and SNU-1), with IC₅₀ values ranging from 1.32 ± 0.14 to 46.34 ± 2.74 μM. Overall, our findings suggest that compounds 1 and 3 may be potential anti-cancer therapeutics and thus warrant further study.

Cytotoxic and pro-apoptotic effects of botanical drugs derived from the indigenous cultivated medicinal plant Paris polyphylla var. yunnanensis

Background: Cancer is one of the top two leading causes of death worldwide. Ethnobotanical research, it is one of methods, which is able to discover effective anticancer drugs based on "prototype" of indigenous people's historical experiences and practices. The rhizomes of Paris polyphylla var. yunnanensis (Franch.) Hand.-Mazz. have been used as botanical drugs to treat cancer by Yi, Bai, Dai, and Naxi ethnic groups in Yunnan, China, where this species is widely cultivated in a large scale in Yunnan. Materials and methods: To identify the substances of anticancer activities based on indigenous medicine knowledge, chromatography was performed to separate saponins from the rhizomes of P. polyphylla var. yunnanensis, followed by spectroscopy to determine the structure of six isolated saponins. The cytotoxicity of five extracts and six pure compounds were evaluated by MTS method. Quantitative determination of total saponins of P. polyphylla var. yunnanensis was analyzed by HPLC. Cell cycle assay, apoptosis assay, and mitochondrial membrane potential were used to evaluate the pro-apoptotic activity in vitro. Results: Five extracts and six pure saponins showed significant inhibitory cytotoxic activities of three human liver cancer cell lines (SMMC-7721, HepG2, and SK-HEP-1) and one non-small-cell lung cancer cell line (A549). The contents of Paris saponins I, II, and VII were 6.96% in the rhizomes of P. polyphylla var. yunnanensis, much higher than Chinese Pharmacopoeia standards (0.6%). Six saponins induced significant apoptosis and cell cycle arrest in three human cancer cell lines (A549, SMMC-7721, and HepG2), which was associated with the loss of mitochondrial membrane potential. Conclusion: The result of this study support that cultivated P. polyphylla var. yunnanensis could be a substitute for wild resource as an anticancer medicine based on indigenous medicine knowledge.

Ent-kaurenoic acid-enriched Mikania glomerata leaves-complexed β-cyclodextrin: Pharmaceutical development and in vivo antitumor activity in a sarcoma 180 mouse model

The extract obtained from Mikania glomerata leaves rich in ent-kaurenoic acid (ERKA) shows cytotoxic activity in vitro, but its hydrophobic nature and thermosensitivity are issues to be solved prior to in vivo antitumor studies. The purpose of this study was to investigate the antitumor activity of inclusion complexes formed between ERKA and β-cyclodextrin (ERKA:β-CD) in rodents. ERKA:β-CD complexes obtained by malaxation (MX) and co-evaporation (CE) methods were firstly characterized regarding their physical properties, encapsulation efficiency, and cytotoxicity againts L929 cells. The antitumor activity study was then performed in mice with sarcoma 180 treated with saline, 5-fluouracil (5FU) and ERKA:β-CD at 30, 100 and 300 µg/kg. The weight, volume, percentage of inhibition growth, gross and pathological features and positivity for TUNEL, ki67, NFκB and NRF2 in the tumors were assessed. Serum lactate-dehydrogenase activity (LDH), white blood cells count (WBC) and both gross and pathological features of the liver, kidneys and spleen were also evaluated. The formation of the inclusion complexes was confirmed by thermal analysis and FTIR, and they were non-toxic for L929 cells. The MX provided a better complexation efficiency. ERKA:β-CD300 promoted significant tumor growth inhibition, and attenuated the tumor mitotic activity and necrosis content, comparable to 5-fluorouracil. ERKA:β-CD300 also increased TUNEL-detected cell death, reduced Ki67 and NF-kB immunoexpression, and partially inhibited the serum LDH activity. No side effect was observed in ERKA:β-CD300-treated animals. The ERKA:β-CD inclusion complexes at 300 µg/kg displays antitumour activity in mice with low systemic toxicity, likely due to inhibition on the NF-kB signaling pathway and LDH activity.

Cyperotundone combined with adriamycin induces apoptosis in MCF-7 and MCF-7/ADR cancer cells by ROS generation and NRF2/ARE signaling pathway

Breast cancer has become the most prevalent cancer, globally. Adriamycin is a first-line chemotherapeutic agent, however, cancer cells acquire resistance to it, which is one of the most common causes of treatment failure. ROS and NRF2 are essential oxidative stress factors that play a key role in the oxidative stress process and are associated with cancer. Our goal is to create novel therapeutic drugs or chemical sensitizers that will improve chemotherapy sensitivity. The optimal concentration and duration for MCF-7 and MCF-7/ADR cells in ADR and CYT were determined using the CCK-8 assay. We found that ADR + CYT inhibited the activity of MCF-7 and MCF-7/ADR cells in breast cancer, as well as causing apoptosis in MCF-7 and MCF-7/ADR cells and blocking the cell cycle in the G0/G1 phase. ADR + CYT induces apoptosis in MCF-7 and MCF-7/ADR cells through ROS generation and the P62/NRF2/HO-1 signaling pathway. In breast cancer-bearing nude mice, ADR + CYT effectively suppressed tumor development in vivo. Overall, our findings showed that CYT in combination with ADR has potent anti-breast cancer cell activity both in vivo and in vitro, suggesting CYT as the main drug used to improve chemosensitivity.

Targeting critical pathways in ferroptosis and enhancing antitumor therapy of Platinum drugs for colorectal cancer

Colorectal cancer (CRC) can be resistant to platinum drugs, possibly through ferroptosis suppression, albeit the need for further work to completely understand this mechanism. This work aimed to sum up current findings pertaining to oxaliplatin resistance (OR) or resistance to ascertain the potential of ferroptosis to regulate oxaliplatin effects. In this review, tumor development relating to iron homeostasis, which includes levels of iron that ascertain cells' sensitivity to ferroptosis, oxidative stress, or lipid peroxidation in colorectal tumor cells that are connected with ferroptosis initiation, especially the role of c-Myc/NRF2 signaling in regulating iron homeostasis, coupled with NRF2/GPX4-mediated ferroptosis are discussed. Importantly, ferroptosis plays a key role in OR and ferroptotic induction may substantially reverse OR in CRC cells, which in turn could inhibit the imbalance of intracellular redox induced by oxaliplatin and ferroptosis, as well as cause chemotherapeutic resistance in CRC. Furthermore, fundamental research of small molecules, ferroptosis inducers, GPX4 inhibitors, or natural products for OR coupled with their clinical applications in CRC have also been summarized. Also, potential molecular targets and mechanisms of small molecules or drugs are discussed as well. Suggestively, OR of CRC cells could significantly be reversed by ferroptosis induction, wherein this result is discussed in the current review. Prospectively, the existing literature discussed in this review will provide a solid foundation for scientists to research the potential use of combined anticancer drugs which can overcome OR via targeting various mechanisms of ferroptosis. Especially, promising therapeutic strategies, challenges ,and opportunities for CRC therapy will be discussed.

Erastin induces ferroptosis in cervical cancer cells via Nrf2/HO-1 signaling pathway

OBJECTIVE

Our research aims to assess the influence of erastin, a ferroptosis-inducing agent, on cervical cancer cells.

INTRODUCTION

Cervical cancer is a prevalent malignancy in females. Dysregulation of ferroptosis, a form of cell demise reliant on iron, is implicated in several cancers.

METHODS

The effect of erastin on HeLa and SiHa was detected by transwell assay, scratch test, and colony formation assay, while cell apoptosis was detected using flow cytometry. Cellular reactive oxygen species (ROS) generation was detected using the dichloro-dihydro-fluorescein diacetate assay. Sequencing analysis identified differentially expressed genes (DEGs), and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) Enrichment analyses were employed to identify the target gene. Subsequently, the utilization of small interfering RNA (siRNA) was employed to suppress the targeted gene expression in HeLa cells, thereby effectively mitigating the impact of erastin on various cellular processes including invasion, colony formation, migration, and ROS generation.

RESULTS

The findings indicate that erastin attenuates the viability of both HeLa cells (IC50 = 30.88 µM) and SiHa cells (IC50 = 29.40 µM). Treatment with erastin at 10 µM inhibits the invasion, colony formation, and migration of both HeLa and SiHa cells within 24 h. Ferrostatin-1 (1 µM) notably alleviates the inhibitory effects of erastin of HeLa and SiHa cells. Upregulation of nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream target, heme oxygenase-1 (HO-1), was found in erastin-treated cells compared to the control group. When knocked down HO-1 in HeLa cells, effectively counteracting the effects of erastin on the invasion, colony formation, migration, and ROS production in HeLa cells.

CONCLUSION

Our research demonstrates that erastin induces ferroptosis and the accumulation of ROS in cervical cancer cells by activating the Nrf2/HO-1 pathway, significantly reducing cell proliferation and motility. These findings propose a potential molecular mechanism of erastin-mediated cervical cancer development.

Novel anthraquinone derivatives trigger endoplasmic reticulum stress response and induce apoptosis

Background: Endoplasmic reticulum (ER) stress is a therapeutic target in cancer given its regulation of bioenergetics and cell death. Methodology & results: We synthesized 14 ER stress-triggered anthraquinone derivatives by introducing an amino group at the 3-position side chain of the lead compound obtained previously. Most of the anthraquinone derivatives exhibited good antitumor activity due to their ability to induce ER damage through cytoplasmic vacuoles. The mechanisms of ER stress caused by compound KA-4c were related to increasing the expression levels of the ATF6 and Bip proteins and upregulating CHOP and cleaved PARP. Conclusion: Compound KA-4c triggers ER stress response and induces apoptosis via the ATF6-CHOP signaling pathway.

Ultrasound-Targeted Microbubble Disruption with Key Nanodroplets for Effective Ferroptosis in Triple-Negative Breast Cancer Using Animal Model

Introduction

Triple-negative breast cancer (TNBC) is known to be the most aggressive form of breast cancer. Due to its high recurrence and mortality rates, the treatment of TNBC is a significant challenge for the medical community. Besides, ferroptosis is an emerging regulatory cell death that may provide new insights into the treatment of TNBC. As a central inhibitor of the ferroptosis process, the selenoenzyme glutathione peroxidase 4 (GPX4) is its classical therapeutic target. However, inhibition of GPX4 expression is quite detrimental to normal tissues. Ultrasound contrast agents, as an emerging visualization precision treatment, may provide a solution to the existing problem.

Methods

In this study, nanodroplets (NDs) carrying simvastatin (SIM) were constructed using the homogeneous/emulsification method. Then, the characterization of SIM-NDs was systematically evaluated. Meanwhile, in this study, the ability of SIM-NDs combined with ultrasound-targeted microbubble disruption (UTMD) to initiate ferroptosis and its respective mechanisms of ferroptosis induction were verified. Finally, the antitumor activity of SIM-NDs was investigated in vitro and in vivo using MDA-MB-231 cells and TNBC animal models.

Results

SIM-NDs exhibited excellent pH- and ultrasound-responsive drug release and noticeable ultrasonographic imaging ability, also showing good biocompatibility and biosafety. UTMD could promote increased intracellular reactive oxygen species and consume intracellular glutathione. However, SIM-NDs were efficiently internalized into cells under ultrasound irradiation, followed by the rapid release of SIM, which inhibited intracellular mevalonate production, and synergistically downregulated GPX4 expression, thereby promoting ferroptosis. Moreover, this combined treatment demonstrated strong antitumor ability in vitro and in vivo.

Conclusion

The combination of UTMD and SIM-NDs presents a promising avenue for harnessing ferroptosis in the treatment of malignant tumors.

HMOX1 Promotes Ferroptosis Induced by Erastin in Lens Epithelial Cell through Modulates Fe2+ Production

PURPOSE

Ferroptosis is defined by the iron-dependent cell death caused by the accumulation of lipid peroxidation. As a major intracellular Fe pools, heme could be metabolized into ferrous iron, carbon monoxide, and biliverdin by Heme oxygenase-1 (HMOX1). Aged human lens epithelium was reported to highly susceptible to ferroptosis, the functional molecular involved in this progress is not explored. Here, we have demonstrated the function of HMOX1 in human lens epithelium during ferroptotic cell death.

METHODS

HMOX1 stably expressed cell line was constructed by lentivirus transfection. HMOX1 knock-out cell line was constructed by Crispr-cas9 technology. Protein expression was detected by western blot. Inverted microscope was applied to record the morphological changes among different treatments. CCK8 assay and colony formation assay were applied to detect the cell proliferation rate. Cell death was detected by PI staining. Lipid Peroxidation was detected by Cell malondialdehyde (MDA) assay. Intracellular Ferrous and Ferric ions were determined using an iron assay kit.

RESULTS

HMOX1 expression was induced significantly in HLECs under erastin treatment in a time-dependent and dosage-dependent manner. Forced expression of HMOX1 increase the sensitivity of HLECs to erastin treatment. However, knock-out or knock-down of HMOX1 improved the cell viability of HLECs significantly under erastin treatment. Iron liberated from heme by HMOX1 might play pivotal role to improve the sensitivity of HLECs in response to erastin.

CONCLUSION

HMOX1 is an essential pro-ferroptosis enzyme which increase the susceptibility of human lens epithelium to erastin. Ferrous iron, a byproduct of heme, might accelerate erastin triggered ferrotosis cell death in human lens epithelium cells.

Insights on Ferroptosis and Colorectal Cancer: Progress and Updates

Patients with advanced-stage or treatment-resistant colorectal cancer (CRC) benefit less from traditional therapies; hence, new therapeutic strategies may help improve the treatment response and prognosis of these patients. Ferroptosis is an iron-dependent type of regulated cell death characterized by the accumulation of lipid reactive oxygen species (ROS), distinct from other types of regulated cell death. CRC cells, especially those with drug-resistant properties, are characterized by high iron levels and ROS. This indicates that the induction of ferroptosis in these cells may become a new therapeutic approach for CRC, particularly for eradicating CRC resistant to traditional therapies. Recent studies have demonstrated the mechanisms and pathways that trigger or inhibit ferroptosis in CRC, and many regulatory molecules and pathways have been identified. Here, we review the current research progress on the mechanism of ferroptosis, new molecules that mediate ferroptosis, including coding and non-coding RNA; novel inducers and inhibitors of ferroptosis, which are mainly small-molecule compounds; and newly designed nanoparticles that increase the sensitivity of cells to ferroptosis. Finally, the gene signatures and clusters that have predictive value on CRC are summarized.

Ferroptosis: Reviewing CRC with the Third Eye

Colorectal cancer (CRC) has been one of the most common cancers and maintains the second-highest incidence and mortality rates among all cancers. The high risk of recurrence and metastasis and poor survival are still huge challenges in CRC therapy, in which the discovery of ferroptosis provides a novel perspective. It has been ten years since a unique type of regulated cell death driven by iron accumulation and lipid peroxidation was proposed and named ferroptosis. During the past decade, there have been multiple pieces of evidence suggesting that ferroptosis participates in the pathophysiological processes during disease progression. In this review, we describe ferroptosis as an imbalance of oxidant systems and anti-oxidants which results in lipid peroxidation, membrane damage, and finally cell death. We elaborate on the mechanisms of ferroptosis and systematically summarize recent studies on the regulatory pathways of ferroptosis in CRC from various perspectives, ranging from encoding genes, noncoding RNAs to regulatory proteins. Finally, we discuss the potential therapeutic role of ferroptosis in CRC treatments.

Endoplasmic reticulum stress-mediated cell death in liver injury

The endoplasmic reticulum is an important intracellular organelle that plays an important role in maintaining cellular homeostasis. Endoplasmic reticulum stress (ERS) and unfolded protein response (UPR) are induced when the body is exposed to adverse external stimuli. It has been established that ERS can induce different cell death modes, including autophagy, apoptosis, ferroptosis, and pyroptosis, through three major transmembrane receptors on the ER membrane, including inositol requirement enzyme 1α, protein kinase-like endoplasmic reticulum kinase and activating transcription factor 6. These different modes of cell death play an important role in the occurrence and development of various diseases, such as neurodegenerative diseases, inflammation, metabolic diseases, and liver injury. As the largest metabolic organ, the liver is rich in enzymes, carries out different functions such as metabolism and secretion, and is the body's main site of protein synthesis. Accordingly, a well-developed endoplasmic reticulum system is present in hepatocytes to help the liver perform its physiological functions. Current evidence suggests that ERS is closely related to different stages of liver injury, and the death of hepatocytes caused by ERS may be key in liver injury. In addition, an increasing body of evidence suggests that modulating ERS has great potential for treating the liver injury. This article provided a comprehensive overview of the relationship between ERS and four types of cell death. Moreover, we discussed the mechanism of ERS and UPR in different liver injuries and their potential therapeutic strategies.

Role of NRF2 in Colorectal Cancer Prevention and Treatment

Nuclear factor erythroid 2-related factor 2 (NRF2) is a basic leucine zipper protein that participates in a complex regulatory network in the body. The activation of NRF2 can prevent and treat colorectal cancer (CRC). A variety of natural compounds can activate NRF2 to inhibit oxidative stress and inflammation to prevent the occurrence and development of CRC, inhibit the proliferation of CRC cells and induce their apoptosis. However, some studies have also shown that it also has negative effects on CRC, such as overexpression of NRF2 can promote the growth of colorectal tumors and increase the drug resistance of chemotherapeutic drugs such as 5-fluorouracil and oxaliplatin. Therefore, inhibition of NRF2 can also be helpful in the treatment of CRC. In this study, we analyze the current research progress of NRF2 in CRC from various aspects to provide new ideas for prevention and treatment based on the NRF2 signaling pathway in CRC.

Radiotherapy modulates tumor cell fate decisions: a review

Cancer has always been a worldwide problem, and the application of radiotherapy has greatly improved the survival rate of cancer patients. Radiotherapy can modulate multiple cell fate decisions to kill tumor cells and achieve its therapeutic effect. With the development of radiotherapy technology, how to increase the killing effect of tumor cells and reduce the side effects on normal cells has become a new problem. In this review, we summarize the mechanisms by which radiotherapy induces tumor cell apoptosis, necrosis, necroptosis, pyroptosis, ferroptosis, autophagy, senescence, mitotic catastrophe, and cuproptosis. An in-depth understanding of these radiotherapy-related cell fate decisions can greatly improve the efficiency of radiotherapy for cancer.

Anti-Metastatic Activity of Tagitinin C from Tithonia diversifolia in a Xenograft Mouse Model of Hepatocellular Carcinoma

Sesquiterpenoid tagitinin C, present in Tithonia diversifolia leaves, has been known to have anti-hepatoma properties. Therefore, we investigated the anti-metastatic potential of tagitinin C in xenograft models of hepatocellular carcinoma (HCC). We isolated tagitinin C from a methanolic extract of the leaves of T. diversifolia. HepG-2 and Huh 7 hepatoma cells were treated with tagitinin C, and cell viability, migration, and matrix metalloproteinase (MPP) activity were assessed using the 3-(4,5-dimethylthiozol-2-yl)-2,5-diphenyltetrazolium bromide assay, scratch migration assay, and MMP activity assay, respectively. We used magnetic resonance spectroscopy to determine the tumorigenicity of xenografts inoculated with Hep-G2 and Huh 7 cells. Tagitinin C was cytotoxic against Hep-G2 and Huh 7 cells, with IC50 values of 2.0 ± 0.1 µg/mL and 1.2 ± 0.1 µg/mL, respectively, and it showed an anti-metastatic effect in vitro. Additionally, MRS assays revealed that tagitinin C (15 g/mouse/day) reduced the tumorigenicity of Hep-G2 and Huh 7 cell xenografts. Tagitinin C demonstrated significant antitumor and anti-metastatic activity in the two human hepatoma cell lines. Tagitinin C might be used as an alternative or auxiliary therapy for the treatment of HCC, and its effect should be further investigated in clinical settings.

Phytochemicals Targeting Ferroptosis: Therapeutic Opportunities and Prospects for Treating Breast Cancer

Ferroptosis, a recently discovered iron-dependent regulated cell death, has been implicated in the therapeutic responses of various cancers including breast cancer, making it a promising therapeutic target to manage this malignancy. Phytochemicals are conventional sources for medication development. Some phytochemicals have been utilized therapeutically to treat cancers as pharmaceutic agents or dietary supplements. Intriguingly, a considerable number of antitumor drugs derived from phytochemicals have been proven to be targeting ferroptosis, thus producing anticancer effects. In this review, we provide a short overview of the interaction between core ferroptosis modulators and breast cancer, illustrating how ferroptosis affects the destiny of breast cancer cells. We also systematically summarize the regulatory effects of phytochemicals on ferroptosis and emphasize their clinical applications in breast cancer suppression, which may accelerate the development of their therapeutic use in breast cancer.

Identification of active natural products that induce lysosomal biogenesis by lysosome-based screening and biological evaluation

Lysosomal biogenesis is an essential adaptive process by which lysosomes exert their function in maintaining cellular homeostasis. Defects in lysosomal enzymes and functions lead to lysosome-related diseases, including lysosomal storage diseases and neurodegenerative disorders. Thus, activation of the autophagy-lysosomal pathway, especially induction of lysosomal biogenesis, might be an effective strategy for the treatment of lysosome-related diseases. In this study, we established a lysosome-based screening system to identify active compounds from natural products that could promote lysosomal biogenesis. The subcellular localizations of master transcriptional regulators of lysosomal genes, TFEB, TFE3 and ZKSCAN3 were examined to reveal the potential mechanisms. More than 200 compounds were screened, and we found that Hdj-23, a triterpene isolated from Walsura cochinchinensis, induced lysosomal biogenesis via activation of TFEB/TFE3. In summary, this study introduced a lysosome-based live cell screening strategy to identify bioactive compounds that promote lysosomal biogenesis, which would provide potential candidate enhancers of lysosomal biogenesis and novel insight for treating lysosome-related diseases.

The Impact of Oxidative Stress and AKT Pathway on Cancer Cell Functions and Its Application to Natural Products

Oxidative stress and AKT serine-threonine kinase (AKT) are responsible for regulating several cell functions of cancer cells. Several natural products modulate both oxidative stress and AKT for anticancer effects. However, the impact of natural product-modulating oxidative stress and AKT on cell functions lacks systemic understanding. Notably, the contribution of regulating cell functions by AKT downstream effectors is not yet well integrated. This review explores the role of oxidative stress and AKT pathway (AKT/AKT effectors) on ten cell functions, including apoptosis, autophagy, endoplasmic reticulum stress, mitochondrial morphogenesis, ferroptosis, necroptosis, DNA damage response, senescence, migration, and cell-cycle progression. The impact of oxidative stress and AKT are connected to these cell functions through cell function mediators. Moreover, the AKT effectors related to cell functions are integrated. Based on this rationale, natural products with the modulating abilities for oxidative stress and AKT pathway exhibit the potential to regulate these cell functions, but some were rarely reported, particularly for AKT effectors. This review sheds light on understanding the roles of oxidative stress and AKT pathway in regulating cell functions, providing future directions for natural products in cancer treatment.

The "Yin and Yang" of Unfolded Protein Response in Cancer and Immunogenic Cell Death

Physiological and pathological burdens that perturb endoplasmic reticulum homeostasis activate the unfolded protein response (UPR), a conserved cytosol-to-nucleus signaling pathway that aims to reinstate the vital biosynthetic and secretory capacity of the ER. Disrupted ER homeostasis, causing maladaptive UPR signaling, is an emerging trait of cancer cells. Maladaptive UPR sustains oncogene-driven reprogramming of proteostasis and metabolism and fosters proinflammatory pathways promoting tissue repair and protumorigenic immune responses. However, when cancer cells are exposed to conditions causing irreparable ER homeostasis, such as those elicited by anticancer therapies, the UPR switches from a survival to a cell death program. This lethal ER stress response can elicit immunogenic cell death (ICD), a form of cell death with proinflammatory traits favoring antitumor immune responses. How UPR-driven pathways transit from a protective to a killing modality with favorable immunogenic and proinflammatory output remains unresolved. Here, we discuss key aspects of the functional dichotomy of UPR in cancer cells and how this signal can be harnessed for therapeutic benefit in the context of ICD, especially from the aspect of inflammation aroused by the UPR.

ALKBH5 inhibits thyroid cancer progression by promoting ferroptosis through TIAM1-Nrf2/HO-1 axis

As a critical catalytic subunit of N6-methyladenosine (m6A) modification in messenger RNA, ALKBH5 has been reported to affect the progression of numerous tumors. However, the functions and mechanisms of ALKBH5 in thyroid cancer remain largely unknown. Relative mRNA and protein levels in thyroid cancer tissues and cells were detected by qRT-PCR and western blot, respectively. The proliferation and viability were evaluated using colony formation and CCK-8 assays. Intracellular iron level was measured by an iron colorimetric assay kit. ROS level was determined using CellRox Green reagent. TIAM1 mRNA m6A level was detected by MeRIP. Xenograft tumor growth was performed to examine the role of ALKBH5 in thyroid tumor growth in vivo. ALKBH5 was decreased in thyroid cancer tissues and cells. ALKBH5 overexpression inhibited thyroid cancer cell proliferation and increased the levels of Fe²⁺ and ROS and reduced the proteins expression of GPX4 and SLC7A11. Furthermore, overexpression of ALKBH5 inhibited TIAM1 expression by m6A modification, and overexpression of TIAM1 reversed the regulatory of oe-ALKBH5 on cell proliferation and ferroptosis in thyroid cancer. In addition, TIAM1 was elevated in thyroid cancer, and TIAM1 knockdown repressed thyroid cancer cell proliferation and promoted ferroptosis through regulating Nrf2/HO-1 axis. In addition, in vivo evidences also showed that ALKBH5 suppressed thyroid cancer progression by decreasing the m6A level of TIAM1. Our findings suggested that ALKBH5 inhibited thyroid cancer progression by inducing ferroptosis through m6A-TIAM1-Nrf2/HO-1 axis, suggesting ALKBH5 might be a potential target molecule for the treatment and diagnosis of thyroid cancer.

Ferroptosis-induced anticancer effect of resveratrol with a biomimetic nano-delivery system in colorectal cancer treatment

Ferroptosis is a novel form of programmed cell death impelled by iron-dependent lipid peroxidation, which may be a potential strategy for cancer therapy. Here we demonstrated for the first time that Resveratrol (RSV), a traditional Chinese medicine (TCM) chemical monomer, could effectually inhibit the growth of colon cancer cells through the ROS-dependent ferroptosis pathway. Mechanistically, RSV evoked the increase of reactive oxygen species and lipid peroxidation in colorectal cancer cells, and eventually lead to ferroptosis. Furthermore, RSV could promote ferroptosis by downregulating the expression of the channel protein solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4). To improve the delivery efficiency of RSV, a biomimetic nanocarrier was developed by coating RSV-loaded poly(ε-caprolactone)–poly(ethylene glycol) (PCL-PEG) nanoparticles with erythrocyte membrane (RSV-NPs@RBCm). The RSV-NPs@RBCm provide the possibility to escape macrophage phagocytosis and have a long circulation effect. In addition, when coupled with a tumor-penetrating peptide iRGD, which could trigger enhanced tissue penetration tumor-specifically, the delivery of RSV-NPs@RBCm into tumors would be significantly improved results from the in vivo study demonstrated an excellent treatment efficacy for CRC. Altogether, our study highlighted the therapeutic potential of RSV as a ferroptosis-inducing anticancer agent and when loaded into a biomimetic nanoplatform, it might pave the way for the application of RSV loaded nanosystems for colorectal cancer treatment.

S-3'-hydroxy-7', 2', 4'-trimethoxyisoxane, a novel ferroptosis inducer, promotes NSCLC cell death through inhibiting Nrf2/HO-1 signaling pathway

Background: Ferroptosis is a newly discovered and promising non-apoptotic programmed cell death (PCD), and inducing ferroptosis in cancer cells could open up a novel avenue for drug screening and cancer therapy. S-3'-hydroxy-7', 2', 4'-trimethoxyisoxane (ShtIX), a new isoflavane compound, has been reported to possess cytotoxicity in non-small cell lung cancer (NSCLC). The aim of this research is to explore the ShtIX-induced cell death form and its underlying molecular mechanism in NSCLC cells. Methods: Cell proliferation, cell cycle arrest, and cell death tests were used to assess the ability of ShtIX to kill NSCLC cells. Iron metabolism, Fe2+ content, reactive oxygen species (ROS) production, lipid peroxide (MDA) level, glutathione (GSH) level, and glutathione peroxidase 4 (GPX4) level were used to determine ferroptosis caused by ShtIX. We employed western blot, quantitative real-time PCR, and Nrf2 interference in NSCLC cells to investigate the roles of Nrf2/HO-1 in ShtIX-induced ferroptosis. In a xenograft nude mouse model, the anticancer efficacy of ShtIX and the function of ferroptosis were studied. Results: Our research shows that ShtIX can selectively kill NSCLC cells while sparing normal cells and that ShtIX-induced cell death can be efficiently reversed by the ferroptosis inhibitors and the iron chelator, but not by other cell death inhibitors. After cells were treated with ShtIX, there was an increase in Fe2+ content and lipid peroxidation accumulation, as well as a drop in GSH and GPX4 levels, all of which are indicators of ferroptosis. ShtIX also reduced the expression of Nrf2 and HO-1, and genetic Nrf2 silencing in NSCLC enhanced the effect of ShtIX-induced ferroptosis. Additionally, ShtIX retards tumor growth and induced ferroptosis through Nrf2/HO-1 signal pathway in the A549 xenograft model, whereas Fer-1 lessens the anticancer effect. Conclusion: This work provided the evidence that ShtIX caused ferroptosis in NSCLC cells, and inhibiting the Nrf2/HO-1 pathway can considerably exacerbate the effect of ShtIX-induced ferroptosis. The study establishes ShtIX as a promising natural ferroptosis inducer for the treatment of NSCLC.

An overview of ferroptosis in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a public health problem associated with high mortality and high morbidity rates worldwide. Presently, its complex pathophysiology is still unclear, and there is no specific drug to reverse NAFLD. Ferroptosis is an iron-dependent and non-apoptotic form of cell death characterized by the iron-induced accumulation of lipid reactive oxygen species (ROS), which damage nucleic acids, proteins, and lipids; generate intracellular oxidative stress; and ultimately cause cell death. Emerging evidence indicates that ferroptosis is involved in the progression of NAFLD, although the mechanism of action of ferroptosis in NAFLD is still poorly understood. Herein, we summarize the mechanism of action of ferroptosis in certain diseases, especially in the pathogenesis of NAFLD, and discuss the potential therapeutic approaches currently used to treat NAFLD. This review also highlights further directions for the treatment and prevention of NAFLD and related diseases.

Ferroptosis and Its Role in Chronic Diseases

Ferroptosis, which has been widely associated with many diseases, is an iron-dependent regulated cell death characterized by intracellular lipid peroxide accumulation. It exhibits morphological, biochemical, and genetic characteristics that are unique in comparison to other types of cell death. The course of ferroptosis can be accurately regulated by the metabolism of iron, lipids, amino acids, and various signal pathways. In this review, we summarize the basic characteristics of ferroptosis, its regulation, as well as the relationship between ferroptosis and chronic diseases such as cancer, nervous system diseases, metabolic diseases, and inflammatory bowel diseases. Finally, we describe the regulatory effects of food-borne active ingredients on ferroptosis.

Ferroptosis and ferritinophagy in diabetes complications

BACKGROUND

With long-term metabolic malfunction, diabetes can cause serious damage to whole-body tissue and organs, resulting in a variety of complications. Therefore, it is particularly important to further explore the pathogenesis of diabetes complications and develop drugs for prevention and treatment. In recent years, different from apoptosis and necrosis, ferroptosis has been recognized as a new regulatory mode of cell death and involves the regulation of nuclear receptor coactivator 4 (NCOA4)-mediated ferritinophagy. Evidence shows that ferroptosis and ferritinophagy play a significant role in the occurrence and development of diabetes complications.

SCOPE OF REVIEW

we systematically review the current understanding of ferroptosis and ferritinophagy, focusing on their potential mechanisms, connection, and regulation, discuss their involvement in diabetes complications, and consider emerging therapeutic opportunities and the associated challenges with future prospects.

MAJOR CONCLUSIONS

In summary, ferroptosis and ferritinophagy are worthy targets for the treatment of diabetes complications, but their complete molecular mechanism and pathophysiological process still require further study.

Atractylodin Induces Apoptosis and Inhibits the Migration of A549 Lung Cancer Cells by Regulating ROS-Mediated Signaling Pathways

Atractylodin (ATR) has anticancer effects on some tumor cells by inducing apoptosis, but its mechanism in lung cancer remains unclear. This study investigates the inhibitory effect of ATR on A549 lung cancer cells. Cell viability was detected by the Cell Counting Kit-8 assay, and results showed that ATR could significantly inhibit the proliferation of A549 cells. Apoptosis was detected by Annexin V-FITC/PI staining, and apoptosis rate and mitochondrial membrane potential were detected by flow cytometry. Results showed that the effect of ATR on the apoptosis of A549 cells was negatively correlated with the change in mitochondrial membrane potential. Western blot analysis showed that ATR regulated apoptosis induced by mitogen-activated protein kinase, signal transducer and activator of transcription 3, and nuclear factor kappa B signaling pathways. Analyses of reactive oxygen species (ROS), cell cycle, and cell migration showed that ATR induced intracellular ROS accumulation as an initiation signal to induce cell cycle arrest regulated by the AKT signaling pathway and cell migration inhibition regulated by the Wnt signaling pathway. Results showed that ATR can inhibit cell proliferation, induce cell apoptosis, induce cell cycle arrest, and inhibit the migration of A549 cells (p < 0.05 was considered statistically significant, * p < 0.05, ** p < 0.01 and *** p < 0.001).

HO-1 Contributes to Luteolin-Triggered Ferroptosis in Clear Cell Renal Cell Carcinoma via Increasing the Labile Iron Pool and Promoting Lipid Peroxidation

Ferroptosis, a novel form of regulated cell death characterized by disrupted iron metabolism and the accumulation of lipid peroxides, has exhibited enormous potential in the therapy of cancer particularly clear cell renal cell carcinoma (ccRCC). Luteolin (Lut), a natural flavonoid widely existing in various fruits and vegetables, has been proven to exert potent anticancer activity in vitro and in vivo. However, previous studies on the anticancer mechanism of Lut have been shown in apoptosis but not ferroptosis. In the present study, we identified that Lut substantially inhibited the survival of ccRCC in vitro and in vivo, and this phenomenon was accompanied by excessively increased intracellular Fe2+ and abnormal depletion of GSH. In addition, Lut induced the imbalance of mitochondrial membrane potential, classical morphological alterations of mitochondrial ferroptosis, generation of ROS, and occurrence of lipid peroxidation in an iron-dependent manner in ccRCC cells. However, these alterations induced by Lut could be reversed to some extent by the iron ion chelator deferiprone or the ferroptosis inhibitor ferrostatin-1, indicating that ccRCC cells treated with Lut underwent ferroptosis. Mechanistically, molecular docking further established that Lut probably promoted the heme degradation and accumulation of labile iron pool (LIP) by excessively upregulating the HO-1 expression, which led to the Fenton reaction, GSH depletion, and lipid peroxidation in ccRCC, whereas blocking this signaling pathway evidently rescued the Lut-induced cell death of ccRCC by inhibiting ferroptosis. Altogether, the current study shows that the natural compound monomer Lut exerted anticancer efficacy by excessively upregulating HO-1 expression and activating LIP to trigger ferroptosis in ccRCC and could be a promising and potent drug candidate for ccRCC treatment.

Ferroptosis and Acute Kidney Injury (AKI): Molecular Mechanisms and Therapeutic Potentials

Acute kidney injury (AKI), a common and serious clinical kidney syndrome with high incidence and mortality, is caused by multiple pathogenic factors, such as ischemia, nephrotoxic drugs, oxidative stress, inflammation, and urinary tract obstruction. Cell death, which is divided into several types, is critical for normal growth and development and maintaining dynamic balance. Ferroptosis, an iron-dependent nonapoptotic type of cell death, is characterized by iron overload, reactive oxygen species accumulation, and lipid peroxidation. Recently, growing evidence demonstrated the important role of ferroptosis in the development of various kidney diseases, including renal clear cell carcinoma, diabetic nephropathy, and AKI. However, the exact mechanism of ferroptosis participating in the initiation and progression of AKI has not been fully revealed. Herein, we aim to systematically discuss the definition of ferroptosis, the associated mechanisms and key regulators, and pharmacological progress and summarize the most recent discoveries about the role and mechanism of ferroptosis in AKI development. We further conclude its potential therapeutic strategies in AKI.

ATF6α promotes prostate cancer progression by enhancing PLA2G4A-mediated arachidonic acid metabolism and protecting tumor cells against ferroptosis

BACKGROUND

Despite the clinical success of androgen receptor (AR)-targeted therapies, prostate cancer (PCa) inevitably progresses to castration-resistant prostate cancer (CRPC). Transcription factor 6 α (ATF6α), an effector of the unfolded protein response (UPR) that modulates the cellular response to endoplasmic reticulum (ER) stress, has been linked to tumor development, metastasis, and relapse. However, the role of ATF6α in CRPC remains unclear.

METHODS

The effect of ATF6α on the CRPC-like phenotype in PCa cells was evaluated by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carb-Oxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium inner salt (MTS), 5-Bromo-2-deoxyUridine (BrdU) incorporation analysis, and cell death assay. Mechanistically, bioinformatic analysis was utilized to evaluate the potential of PLA2G4A as the target of ATF6α. Moreover, Western blot analysis, real-time polymerase chain reaction, chromatin immunoprecipitation, arachidonic acid (AA), and prostaglandin E2 (PGE2) assays were performed to identify the regulatory effect of ATF6α on PLA2G4A.

RESULTS

In this study, we found that the increase of ATF6α expression in response to androgen deprivation generates PCa cells with a CRPC-like phenotype. PCa cells with high levels of ATF6α expression are resistant to ferroptosis, and genetic and pharmacological inhibition of ATF6α could, therefore, promote the ferroptotic death of tumor cells and delay PCa progression. Molecular analyses linked ATF6α regulation of ferroptosis to the PLA2G4A-mediated release of AA and the resulting increase in PGE2 production, the latter of which acts as an antiferroptotic factor.

CONCLUSIONS

This study defines ATF6α as a novel antiferroptotic regulator that exacerbates PCa progression. In addition, our data establish ATF6α-PLA2G4A signaling as an important pathological pathway in PCa, and targeting this pathway may be a novel treatment strategy.

Insamgobonhwan Protects Neuronal Cells from Lipid ROS and Improves Deficient Cognitive Function

Iron is an essential element in the central nervous system that is involved in many of its important biological processes, such as oxygen transportation, myelin production, and neurotransmitter synthesis. Previous studies have observed the selective accumulation of iron in Aβ aggregates and neurofibrillary tangles in the brains of patients with Alzheimer's disease, and excess of this accumulation is associated with accelerated cognitive decline in Alzheimer's patients. Emerging evidence suggests that ferroptosis, cell death due to iron accumulation, is a potential therapeutic target for treating Alzheimer's disease. Insamgobonhwan (GBH) is a well-regarded traditional medicine from Donguibogam that possess antioxidant properties and has been suggested to slow the aging process. However, the neuroprotective role of GBH against lipid peroxidation-induced ferroptosis and its positive cognitive effects remain unexplored. Here, we investigated the ability of GBH to protect against RSL3-induced ferroptosis in vitro and to suppress amyloid-β-induced cognitive impairment in vivo. First, we treated HT22 cells with RSL3 to induce ferroptosis, which is an inhibitor of glutathione peroxidase 4 (GPX4) and induces lethal lipid hydroperoxide accumulation, reactive oxygen species (ROS) production, and ferroptotic cell death. GBH treatment inhibited cell death and lipid peroxidation, which were increased by RSL3 administration. In addition, GBH restored the expression of ferroptosis marker proteins, such as GPX4, HO-1 and COX-2, which were altered by RSL3. Next, we examined whether the protective ability of GBH in cells was reproduced in animals. We concluded that GBH treatment inhibited Aβ-induced lipid peroxidation and improved Aβ-induced cognitive impairment in mice.

Auriculasin enhances ROS generation to regulate colorectal cancer cell apoptosis, ferroptosis, oxeiptosis, invasion and colony formation

Colorectal cancer (CRC) is one of the most common malignant tumors in the digestive system, and Chinese herbal medicine plays an important role in tumor treatment. The in-depth study of auriculasin isolated from Flemingia philippinensis showed that auriculasin promoted reactive oxygen species (ROS) generation in a concentration-dependent manner; when ROS scavenger NAC was added, the effects of auriculasin in promoting ROS generation and inhibiting cell viability were blocked. Auriculasin induced CRC cell apoptosis, led to mitochondrial shrinkage, and increased the intracellular accumulation of Fe²⁺ and MDA. When auriculasin and NAC were added simultaneously, the levels of apoptosis, Fe²⁺ and MDA returned to the control group levels, indicating that auriculasin activated apoptosis and ferroptosis by inducing ROS generation. In addition, auriculasin promoted the expression of Keap1 and AIFM1, but significantly reduced the phosphorylation level of AIFM1, while NAC significantly blocked the regulation of Keap1 and AIFM1 by auriculasin, which indicates that auriculasin can also induce oxeiptosis through ROS. When Z-VAD-FMK, Ferrostatin-1, Keap1 siRNA, PGAM5 siRNA and AIFM1 siRNA were added respectively, the inhibitory effect of auriculasin on cell viability was significantly weakened, indicating that auriculasin inhibits cell viability by inducing apoptosis, ferroptosis and oxeiptosis. Auriculasin also inhibited the invasion and clone forming ability of CRC cells, while NAC blocked the above effects of auriculasin. Therefore, auriculasin can promote CRC cell apoptosis, ferroptosis and oxeiptosis by inducing ROS generation, thereby inhibiting cell viability, invasion and clone formation, indicating that auriculasin has a significant antitumor effect.

Research progress on ferroptosis in diabetic kidney disease

Ferroptosis is a newly discovered form of cell death that differs from other forms of regulated cell death at morphological, biochemical, and genetic levels, and is characterized by iron-dependent accumulation of lipid peroxides. Ferroptosis is closely related to intracellular metabolism of amino acids, lipids, and iron. Hence, its regulation may facilitate disease intervention and treatment. Diabetic kidney disease is one of the most serious complications of diabetes, which leads to serious psychological and economic burdens to patients and society when it progresses to end-stage renal disease. At present, there is no effective treatment for diabetic kidney disease. Ferroptosis has been recently identified in animal models of diabetic kidney disease. Herein, we systematically reviewed the regulatory mechanism of ferroptosis, its association with different forms of cell death, summarized its relationship with diabetic kidney disease, and explored its regulation to intervene with the progression of diabetic kidney disease or as a treatment.

Ferroptosis: A Double-Edged Sword in Gastrointestinal Disease

Ferroptosis is a novel form of regulated cell death (RCD) that is typically accompanied by iron accumulation and lipid peroxidation. In contrast to apoptosis, autophagy, and necroptosis, ferroptosis has unique biological processes and pathophysiological characteristics. Since it was first proposed in 2012, ferroptosis has attracted attention worldwide. Ferroptosis is involved in the progression of multiple diseases and could be a novel therapeutic target in the future. Recently, tremendous progress has been made regarding ferroptosis and gastrointestinal diseases, including intestinal ischemia/reperfusion (I/R) injury, inflammatory bowel disease (IBD), gastric cancer (GC), and colorectal cancer (CRC). In this review, we summarize the recent progress on ferroptosis and its interaction with gastrointestinal diseases. Understanding the role of ferroptosis in gastrointestinal disease pathogenesis could provide novel therapeutic targets for clinical treatment.