Ferroptosis in cancer therapy: a novel approach to reversing drug resistance

FASN contributes to ADM resistance of diffuse large B-cell lymphoma by inhibiting ferroptosis via nf-κB/STAT3/GPX4 axis

Drug resistance is a critical impediment to efficient therapy of diffuse large B-cell lymphoma (DLBCL) patients. Recent studies have highlighted the association between ferroptosis and drug resistance that has been reported. Fatty acid synthase (FASN) is always related to a poor prognosis. In this study, we investigate the impact of FASN on drug resistance in DLBCL and explore its potential modulation of ferroptosis mechanisms. The clinical correlation of FASN mRNA expression was first analyzed to confirm the role of FASN on drug resistance in DLBCL based on the TCGA database. Next, the impact of FASN on ferroptosis was investigated in vitro and in vivo. Furthermore, a combination of RNA-seq, western blot, luciferase reporter, and ChIP experiments was employed to elucidate the underlying mechanism. The prognosis for patients with DLBCL was worse when FASN was highly expressed, particularly in those undergoing chemotherapy for Adriamycin (ADM). FASN promoted tumor growth and resistance of DLBCL to ADM, both in vitro and in vivo. It is noteworthy that this effect was achieved by inhibiting ferroptosis, since Fer-1 (a ferroptosis inhibitor) treatment significantly recovered the effects of silencing FASN on inhibiting ferroptosis, while Erastin (a ferroptosis inducer) treatment attenuated the impact of overexpressing FASN. Mechanistically, FASN activated NF-κB/STAT3 signaling pathway through phosphorylating the upstream IKKα and IκBα, and the activated STAT3 promoted GPX4 expression by directly binding to GPX4 promoter. FASN inhibits ferroptosis in DLBCL via NF-κB/STAT3/GPX4 signaling pathway, indicating its critical role in mediating ADM resistance of DLBCL.

Benja-ummarit induces ferroptosis with cell ballooning feature through ROS and iron-dependent pathway in hepatocellular carcinoma

ETHNOPHARMACOLOGICAL RELEVANCE

Benja-ummarit (BU), a traditional Thai herbal formula, has been prescribed by traditional Thai practitioners for the treatment of liver cancer. Clinical trials of BU have shown an increase in overall survival in hepatocellular carcinoma (HCC) patients, including stage 1-3 (with or without prior standard chemotherapy) and terminal stage. The clinical outcomes differ from those of other apoptosis-based conventional chemotherapies. The molecular mechanisms underlying the anti-cancer properties of BU remain unclear.

AIM OF STUDY

To investigate BU-induced ferroptosis through morphological and molecular analyses of HCC cell lines and HCC rat tissues.

METHODOLOGY

Cytotoxicity of BU extract in HepG2 and HuH-7 cells, with or without LX-2 in 2D and 3D cultures, was determined through MTT assay and by observing spheroid formation, respectively, as compared to sorafenib. Morphological changes and the cellular ultrastructure of the treated cells were evaluated by light microscopy and transmission electron microscopy (TEM), respectively. In addition, alterations in ferroptosis protein markers in both cell lines and rat liver tissue were determined using western blot analysis and immunohistochemical staining, respectively. To investigate the pathways mediating ferroptosis, cells were pretreated with an iron chelator to confirm the iron-dependent ferroptosis induced by the BU extract. Intracellular ROS, a mediator of ferroptosis, was measured using a scanning ion conductance microscope (SICM). SICM was also used to determine cellular stiffness. The lipid profiles of BU-treated cells were studied using LC-MS/MS.

RESULTS

The BU extract induced cell death under all HCC cell culture conditions. The BU-IC50 in HepG2 and HuH-7 were 31.24 ± 4.46 μg/mL and 23.35 ± 0.27 μg/mL, respectively as determined by MTT assay. In co-culture with LX-2, BU exhibited a similar trend of cytotoxicity in both HepG2 and HuH-7 cells. Light microscopy showed cell ballooning features with intact plasma membranes, and TEM microscopy showed mitochondrial swelling and reduced mitochondrial cristae in BU-treated cells. BU promotes intracellular iron levels by increasing DMT1 and NCOA4 expression and decreasing FTH1 expression. BU also suppressed the cellular antioxidant system by lowering CD98, NRF2, and GPX4 expression, and promoting KEAP1 expression. IHC results of HCC rat liver tissues showed the absence of DMT1 and high expression of GPX4 in the tumor area. Pre-treatment with an iron chelator partially restored cell viability and shifted the mode of cell death to a more apoptosis-like morphology in the BU-treated group. The SICM showed increased intracellular ROS levels and cellular stiffness 24 h after BU treatment. In more detail of BU-mediated ferroptosis, cellular lipid profiling revealed increased expression of 3 polyunsaturated lipids, which are highly susceptible to lipid peroxidation, in BU-treated cells.

DISCUSSION

Alterations in intracellular iron levels, ROS levels, and cellular lipid composition have been previously reported in cancer cells. Therefore, targeting the iron-dependent ROS pathway and polyunsaturated lipids via BU-induced ferroptosis may be more cancer-specific than apoptosis-based cancer drugs. These observations are in accordance with the clinical outcomes of BU. The ferroptosis-inducing mechanism of BU makes it an extremely promising novel drug candidate for the treatment of HCC.

Solanum torvum induces ferroptosis to suppress hepatocellular carcinoma

ETHNOPHARMACOLOGICAL RELEVANCE

Solanum torvum Sw. (ST) is used to clear heat toxins, promote blood circulation, and alleviate blood stasis. Therefore, this plant has traditionally been used as an ethnomedicine for common cold, chronic gastritis, and tumors.

AIM OF THE STUDY

This study aimed to elucidate the mechanism by which ST induces ferroptosis in hepatocellular carcinoma (HCC), the combination effect with lenvatinib, and the impact on lenvatinib-resistant cells.

MATERIALS AND METHODS

Cell viability assays were performed using different hepatoma cell lines treated with ST. Lipid peroxidation and iron assays were performed using flow cytometry. Molecules involved in the ferroptosis pathway were detected by Western blotting. Finally, a lenvatinib-resistant cell line was established to evaluate the antiproliferative effects of ST.

RESULTS

ST ethanol extract inhibited the growth of various hepatoma cell lines. A significant reduction in glutathione peroxidase 4 (GPX4) expression was observed following ST treatment, which was accompanied by increased lipid peroxidation and Fe2+ accumulation. ST induced ferroptosis mainly through heme oxygenase-1 (HO-1) expression. HO-1 knockdown reduced ST-induced lipid peroxidation and reversed GPX4 suppression. Acyl-CoA synthetase long-chain family member 4 (ACSL4) also participated in ST-induced ferroptosis. ST and lenvatinib combination showed an additive effect, and ST retained its potential anti-HCC efficacy in a lenvatinib-resistant cell line.

CONCLUSION

This study demonstrated that the ethanol extract of ST inhibits hepatoma cell growth by inducing ferroptosis. ST displayed an additive effect with lenvatinib in Hep 3B cells and showed remarkable anti-HCC activity in lenvatinib-resistant Hep 3B cells. Collectively, the study shows that ST might have the potential to reduce lenvatinib use in clinical practice and salvage cases of lenvatinib resistance.

Ferroptosis: Potential therapeutic targets and prognostic predictions for acute myeloid leukemia (Review)

Ferroptosis is a relatively recently discovered type of regulated cell death that is induced by iron-dependent lipid peroxidation. The key contributing factors to ferroptosis are the loss of glutathione peroxidase 4 which is required for reversing lipid peroxidation, the buildup of redox-active iron and the oxidation of phospholipids containing polyunsaturated fatty acids. Ferroptosis has been associated with a number of diseases, including cancers such as hepatocellular carcinoma, breast cancer, acute renal damage and neurological disorders such as Alzheimer's disease and Alzheimer's disease, and there may be an association between ferroptosis and acute myeloid leukemia (AML). The present review aims to describe the primary regulatory pathways of ferroptosis, and the relationship between ferroptosis and the occurrence and development of AML. Furthermore, the present review comprehensively summarizes the latest advances in the treatment and prognosis of ferroptosis in AML.

Emerging insights into ferroptosis in cholangiocarcinoma (Review)

Cholangiocarcinoma (CCA) is a malignant tumor that arises within the biliary system, which exhibits a progressively increasing incidence and a poor patient prognosis. A thorough understanding of the molecular pathogenesis that drives the progression of CCA is essential for the development of effective molecular target therapeutic approaches. Ferroptosis is driven by excessive iron accumulation and catalysis, lipid peroxidation and the failure of antioxidant defense systems. Key molecular targets of iron metabolism, lipid metabolism and antioxidant defense systems involve molecules such as transferrin receptor, ACSL4 and GPX4, respectively. Inhibitors of ferroptosis include ferrostatin-1, liproxstatin-1, vitamin E and coenzyme Q10. By contrast, compounds such as erastin, RSL3 and FIN56 have been identified as inducers of ferroptosis. Ferroptosis serves a notable role in the onset and progression of CCA. CCA cells exhibit high sensitivity to ferroptosis and aberrant iron metabolism in these cells increases oxidative stress and iron accumulation. The induction of ferroptosis markedly reduces the ability of CCA cells to proliferate and migrate. Certain ferroptosis agonists, such as RSL3 and erastin, cause lipid peroxide build up and GPX4 inhibition to induce ferroptosis in CCA cells. Current serological markers, such as CA-199, have low specificity and cause difficulties in the diagnosis of CCA. However, novel techniques, such as non-invasive liquid biopsy and assays for oxidative stress markers and double-cortin-like kinase 1, could improve diagnostic accuracy. CCA is primarily treated with surgery and chemotherapy. A close association between the progression of CCA with ferroptosis mechanisms and related regulatory pathways has been demonstrated. Therefore, it could be suggested that multi-targeted therapeutic approaches, such as ferroptosis inducers, iron chelating agents and novel modulators such as YL-939, may improve treatment efficacy. Iron death-related genes, such as GPX4, that are highly expressed in CCA and are associated with a poor prognosis for patients may represent potential prognostic markers for CCA. The present review focused on molecular targets such as p53 and ACSL4, the process of targeted medications in combination with PDT in CCA and the pathways of lipid peroxidation, the Xc-system and GSH-GPX4 in ferroptosis. The present review thus offered novel perspectives to improve the current understanding of CCA.

Cytoglobin attenuates melanoma malignancy but protects melanoma cells from ferroptosis

Cutaneous malignant melanoma is the most aggressive and the deadliest form of skin cancer. There are two types of limitations which universally exist in current melanoma therapy: Adverse effects and reduced efficiency. Cytoglobin (CYGB), an iron hexacoordinated globin, is highly enriched in melanocytes and frequently epigenetically silenced during melanoma genesis. The present study aimed to explore its potential role as a biomarker for ferroptosis treatment. It was observed that B16F10 and A375 melanoma cells with loss of CYGB expression were highly sensitive to ferroptosis inducers RSL3 and erastin, whereas G361 melanoma cells with highly enriched CYGB were resistant to RSL3 or erastin. Ectopically overexpressed CYGB rendered B16F10 and A375 cells resistant to RSL3 or erastin, accompanied by decreased proliferation and epithelial‑mesenchymal transition (EMT). By contrast, knockdown of CYGB expression made G361 cells sensitive to ferroptosis induction but induced proliferation and EMT progression of G361 cells. Mechanistically, CYGB‑induced resistance of melanoma cells to ferroptosis may have been associated, in part, with i) Suppression of EMT; ii) upregulation of glutathione peroxidase 4 expression; iii) decrease of labile iron pool. In vivo study also demonstrated that CYGB overexpression rendered xenograft melanoma much more resist to RSL3 treatment. Based on these findings, CYGB is a potential therapeutic biomarker to screen the melanoma patients who are most likely benefit from ferroptosis treatment.

Investigating the mechanism of ferroptosis induction by sappanone A in hepatocellular carcinoma: NRF2/xCT/GPX4 axis

Hepatocellular carcinoma (HCC) is a prevalent and lethal malignancy with significant global impact, necessitating the development of novel therapeutic strategies and drugs. Ferroptosis, a newly identified form of iron-dependent programmed cell death, has emerged as a promising strategy to combat HCC. Sappanone A, an isoflavone compound derived from the heartwood of Biancaea sappan (L.) Tod., is known for its anti-inflammatory and antioxidant properties. However, its anti-HCC effects and underlying mechanisms remain unclear. This study is the first time to demonstrate the anti-tumor effect of Sappanone A on HCC both in vitro and in vivo, through the assessment of cell viability and apoptosis following Sappanone A treatment. Flow cytometry and confocal microscopy revealed that Sappanone A induced ferroptosis in HCC cells by increasing Fe2+ accumulation, reactive oxygen (ROS) level, and lipid peroxidation, specifically targeting inosine monophosphate dehydrogenase-2 (IMPDH2). Additionally, Western blot analysis suggested that the anti-HCC effects of Sappanone A were mediated through the regulation of the NRF2/xCT/GPX4 axis, highlighting its potential to enhance ferroptosis in HCC cells and underscoring the critical role of IMPDH2 in HCC treatment.

New Emerging Therapeutic Strategies Based on Manipulation of the Redox Regulation Against Therapy Resistance in Cancer

Background: Resistance to standard therapeutic methods, including chemotherapy, immunotherapy, and targeted therapy, remains a critical challenge in effective cancer treatment. Redox homeostasis modification has emerged as a promising approach to address medication resistance. Objective: This review aims to explore the mechanisms of redox alterations and signaling pathways contributing to treatment resistance in cancer. Methods: In this study, a comprehensive review of the molecular mechanisms underlying drug resistance governed by redox signaling was conducted. Emphasis was placed on understanding how tumor cells manage increased reactive oxygen species (ROS) levels through upregulated antioxidant systems, enabling resistance across multiple therapeutic pathways. Results: Key mechanisms identified include alterations in drug efflux, target modifications, metabolic changes, enhanced DNA damage repair, stemness preservation, and tumor microenvironment remodeling. These pathways collectively facilitate tumor cells' adaptive response and resistance to various cancer treatments. Conclusion: Developing a detailed understanding of the interrelationships between these redox-regulated mechanisms and therapeutic resistance holds potential to improve treatment effectiveness, offering valuable insights for both fundamental and clinical cancer research. Antioxid. Redox Signal. 00, 000-000.

MGST1 facilitates novel KRASG12D inhibitor resistance in KRASG12D-mutated pancreatic ductal adenocarcinoma by inhibiting ferroptosis

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal cancer with a low 5-year survival rate. Treatment options for PDAC patients are limited. Recent studies have shown promising results with MRTX1133, a KRASG12D inhibitor that demonstrated potent antitumor activity in various types of tumors with KRASG12D mutation. Resistance to KRAS inhibitors is frequently occurred and one of the main reasons for treatment failure. Understanding resistance mechanisms to novel KRAS inhibitors is crucial to ensure sustained and durable remissions.

METHODS

Two KRASG12D inhibitor MRTX1133-resistant PDAC cell lines were established in vitro. The resistance mechanisms to KRASG12D inhibitor MRTX1133 against PDAC in vitro and in vivo were characterized by RNA sequencing, reverse transcript polymerase chain reaction, cytotoxicity test, plasmid transfection, lentivirus transfection, lipid peroxidation detection, malondialdehyde levels detection, glutathione levels detection, western blot, immunofluorescence, nude mice tumorigenesis experiment and immunohistochemistry.

RESULTS

The bioinformatics analysis and transcriptome sequencing showed that ferroptosis was involved in the resistant effect of the KRASG12D inhibitor treatment, and MGST1 was the key molecule against MRTX1133-induced ferroptosis. Increased expression of MGST1 weakened the cytotoxicity of MRTX1133 by inhibiting lipid peroxidation-induced ferroptosis in KRASG12D inhibitor-resistant PDAC cells. Knockdown or overexpression of MGST1 conferred sensitivity or resistance to KRASG12D inhibitor MRTX1133, respectively. Mechanismly, increased nuclear localization and higher levels of active β-catenin were observed in MRTX1133-resistant PDAC cells, which contributed to higher MGST1 expression. Knockdown of CTNNB1 or TCF4 can decreased MGST1 expression. Additionally, we found that PKF-118-310, an antagonist of β-catenin/Tcf4 complex, repressed MGST1 expression. In both in vitro and in vivo models, a synergistic effect was observed when combining MRTX1133 and PKF-118-310 in KRASG12D inhibitor MRTX1133-resistant PDAC cells and tumors.

CONCLUSION

Our data showed that KRASG12D inhibitor MRTX1133 combined with PKF-118-310 could enhance the effectiveness of MRTX1133 treatment response through induction of ferroptosis via inhibiting MGST1 expression in MRTX1133-resistant PDAC cells and tumors. This evidence may provide a promising strategy to overcome KRASG12D inhibitor MRTX1133 resistance in PDAC patients with KRASG12D mutations.

Construction of Prognostic Prediction Models for Colorectal Cancer Based on Ferroptosis-Related Genes: A Multi-Dataset and Multi-Model Analysis

Background

Colorectal cancer (CRC) remains a significant health burden globally, necessitating a deeper understanding of its molecular landscape and prognostic markers. This study characterized ferroptosis-related genes (FRGs) to construct models for predicting overall survival (OS) across various CRC datasets.

Methods

In TCGA-COAD dataset, differentially expressed genes (DEGs) were identified between tumor and normal tissues using DESeq2 package. Prognostic genes were identified associated with OS, disease-specific survival, and progression-free interval using survival package. Additionally, FRGs were downloaded from FerrDb website, categorized into unclassified, marker, and driver genes. Finally, multiple models (Coxboost, Elastic Net, Gradient Boosting Machine, LASSO Regression, Partial Least Squares Regression for Cox Regression, Ridge Regression, Random Survival Forest [RSF], stepwise Cox Regression, Supervised Principal Components analysis, and Support Vector Machines) were employed to predict OS across multiple datasets (TCGA-COAD, GSE103479, GSE106584, GSE17536, GSE17537, GSE29621, GSE39084, GSE39582, and GSE72970) using intersection genes across DEGs, OS, disease-specific survival, and progression-free interval, and FRG categories.

Results

Six intersection genes (ASNS, TIMP1, H19, CDKN2A, HOTAIR, and ASMTL-AS1) were identified, upregulated in tumor tissues, and associated with poor survival outcomes. In the TCGA-COAD dataset, the RSF model demonstrated the highest concordance index. Kaplan-Meier analysis revealed significantly lower OS probabilities in high-risk groups identified by the RSF model. The RSF model exhibited high accuracy with AUC values of 0.978, 0.985, and 0.965 for 1-, 3-, and 5-year survival predictions, respectively. Calibration curves demonstrated excellent agreement between predicted and observed survival probabilities. Decision curve analysis confirmed the clinical utility of the RSF model. Additionally, the model's performances were validated in GSE29621 dataset.

Conclusions

The study underscores the prognostic relevance of 6 intersection genes in CRC, providing insights into potential therapeutic targets and biomarkers for patient stratification. The RSF model demonstrates robust predictive performance, suggesting its utility in clinical risk assessment and personalized treatment strategies.

The deubiquitinase OTUD5 stabilizes SLC7A11 to promote progression and reduce paclitaxel sensitivity in triple-negative breast cancer

Ferroptosis is a newly defined form of programmed cell death characterized by iron-dependent lipid peroxide accumulation and is associated with the progression of cancer. Solute carrier family 7 member 11 (SLC7A11), a key component of cystine/glutamate antiporter, has been characterized as a critical regulator of ferroptosis. Although many studies have established the transcriptional regulation of SLC7A11, it remains largely unknown how the stability of SLC7A11 is regulated in cancers, especially in triple-negative breast cancer (TNBC). Here we demonstrated that ovarian tumor domain-containing protein 5 (OTUD5), which deubiquitinated and stabilized SLC7A11, played a key role in TNBC progression and paclitaxel chemosensitivity through modulating ferroptosis. The clinical data analysis showed OTUD5 was higher expressed in TNBC, which positively correlated with SLC7A11 level. Mechanistically, OTUD5 interacted with SLC7A11 and cleaved K48-linked polyubiquitin chains from SLC7A11 to enhance the stability of SLC7A11. Taken together, these findings uncover a functional and mechanistic role of OTUD5 in TNBC progression and paclitaxel sensitivity, indicating OTUD5 could be a potential target for TNBC treatment.

The role of lncRNA binding to RNA‑binding proteins to regulate mRNA stability in cancer progression and drug resistance mechanisms (Review)

Cancer is a disease that poses a serious threat to human health, the occurrence and development of which involves complex molecular mechanisms. Long non‑coding RNAs (lncRNAs) and RNA‑binding proteins (RBPs) are important regulatory molecules within cells, which have garnered extensive attention in cancer research in recent years. The binding of lncRNAs and RBPs plays a crucial role in the post‑transcriptional regulation of mRNA, affecting the synthesis of proteins related to cancer by regulating the stability of mRNA. This, in turn, regulates the malignant biological behaviors of tumor cells, such as proliferation and metastasis, and serves an important role in therapeutic resistance. The present study reviewed the role of lncRNA‑RBP interactions in the regulation of mRNA stability in various malignant tumors, with a focus on the molecular mechanisms underlying this regulatory interaction. The aim of the present review was to gain a deeper understanding of these molecular mechanisms to provide new strategies and insights for the precise treatment of cancer.

Simeprevir induces ferroptosis through β-TrCP/Nrf2/GPX4 axis in triple-negative breast cancer cells

The effective treatment regimens of triple-negative breast cancer (TNBC), a specific subtype of breast cancer (BC) with proneness to relapse and poor prognosis, are still lacking. Simeprevir (SIM), approved for hepatitis C infection treatment, has been proved to be a competitive drug for the treatment of various solid tumors recently. However, the anti-tumor mechanisms of SIM and therapeutic effects on TNBC are uncertain. In this study, we suggested that SIM effectively restrained the growth of MDA-MB-231 and BT-549 cells, two cell lines from TNBC. The RNA sequencing revealed that ferroptosis signaling was activated in SIM-treated TNBC cells. SIM induced ferroptosis in TNBC cells through reduced glutathione (GSH) levels, increased iron levels, ROS and lipid peroxidation. Mechanistically, SIM promoted the expression of β-TrCP to inhibit the Nrf2/GPX4 axis in TNBC cells, leading to ferroptosis. Moreover, SIM administration into the xenografts formed by MDA-MB-231 dramatically suppressed the tumor progression by inducing ferroptosis in vivo. Collectively, this finding reveals that SIM may serve as a competitive therapeutic strategy to inhibit TNBC.

STIM1 promotes acquired resistance to sorafenib by attenuating ferroptosis in hepatocellular carcinoma

Dysregulated calcium (Ca2+) signaling pathways are associated with tumor cell death and drug resistance. In non-excitable cells, such as hepatocellular carcinoma (HCC) cells, the primary pathway for Ca2+ influx is through stromal interaction molecule 1 (STIM1)-mediated store-operated calcium entry (SOCE). Previous studies have demonstrated the involvement of STIM1-mediated SOCE in processes such as genesis, metastasis, and stem cell self-renewal of HCC. However, it remains unclear whether STIM1-mediated SOCE plays a role in developing acquired resistance to sorafenib in HCC patients. In this study, we established acquired sorafenib-resistant (SR) HCC cell lines by intermittently exposing them to increasing concentrations of sorafenib. Our results showed higher levels of STIM1 and stronger SOCE in SR cells compared with parental cells. Deleting STIM1 significantly enhanced sensitivity to sorafenib in SR cells, while overexpressing STIM1 promoted SR by activating SOCE. Mechanistically, STIM1 increased the transcription of SLC7A11 through the SOCE-CaN-NFAT pathway. Subsequently, up-regulated SLC7A11 increased glutathione synthesis, resulting in ferroptosis insensitivity and SR. Furthermore, combining the SOCE inhibitor SKF96365 with sorafenib significantly improved the sensitivity of SR cells to sorafenib both in vitro and in vivo. These findings suggest a potential strategy to overcome acquired resistance to sorafenib in HCC cells.

Targeting ALDH1A1 to enhance the efficacy of KRAS-targeted therapy through ferroptosis

KRAS is among the most commonly mutated oncogenes in human malignancies. Although the advent of sotorasib and adagrasib, has lifted the "undruggable" stigma of KRAS, the resistance to KRAS inhibitors quickly becomes a major issue. Here, we reported that aldehyde dehydrogenase 1 family member A1 (ALDH1A1), an enzyme in retinoic acid biosynthesis and redox balance, increases in response to KRAS inhibitors and confers resistance in a range of cancer types. KRAS inhibitors' efficacy is significantly improved in sensitive or drug-resistant cells, patient-derived organoids (PDO), and xenograft models by ALDH1A1 knockout, loss of enzyme function, or inhibitor. Furthermore, we discovered that ALDH1A1 suppresses the efficacy of KRAS inhibitors by counteracting ferroptosis. ALDH1A1 detoxicates deleterious aldehydes, boosts the synthesis of NADH and retinoic acid (RA), and improves RARA function. ALDH1A1 also activates the CREB1/GPX4 pathway, stimulates the production of lipid droplets in a pH-dependent manner, and subsequently prevents ferroptosis induced by KRAS inhibitors. Meanwhile, we established that GTF2I is dephosphorylated at S784 via ERK by KRAS inhibitors, which hinders its nuclear translocation and mediates ALDH1A1's upregulation in response to KRAS inhibitors. In summary, the results offer valuable insights into targeting ALDH1A1 to enhance the effectiveness of KRAS-targeted therapy through ferroptosis in cancer treatment.

Mutual regulation between histone methyltransferase Suv39h1 and the Wnt/β-catenin signaling pathway promoted cell proliferation and inhibited apoptosis in bone marrow mesenchymal stem cells exposed to hydroquinone

Hydroquinone (HQ), a metabolite of benzene, is frequently utilized as a surrogate for benzene in in vitro studies and is associated with the development of acute myeloid leukemia (AML). In the hemotoxicity caused by benzene and HQ, cell apoptosis plays a key role. However, the molecular mechanisms underlying HQ are unknown. Studies have indicated that Suv39h1 is involved in regulating cell division and proliferation by regulating histone H3K9me3. Meanwhile, the Wnt/β-catenin signaling pathway also plays a significant role in cell proliferation and apoptosis. Therefore, this study was aimed at exploring the regulatory role of Suv39h1 and the Wnt/β-catenin signaling pathway in the effects of HQ on bone marrow mesenchymal stem cells (BMSCs), as well as its influence on cell proliferation and apoptosis. The results demonstrated that HQ elevated the levels of Suv39h1 and H3K9me3 and activated the Wnt/β-catenin signaling pathway by upregulating β-catenin, Wnt2b, C-myc, and Cyclin D1 and downregulating Wnt5a, resulting in an increase in cell growth and a decrease in apoptosis. Suv39h1 knockdown inhibited the Wnt/β-catenin signaling pathway. Meanwhile, inhibition of the Wnt/β-catenin signaling pathway resulted in the down-regulation of Suv39h1 and H3K9me3 in BMSCs. They both promoted cell proliferation and inhibited apoptosis in the effects of HQ on BMSCs by downregulating the expression of Cyt-C, Bax, Caspase 3, and Caspase 9 and upregulating the expression of Bcl-xl. Therefore, we concluded that Suv39h1 and the Wnt/β-catenin signaling pathway may mutually regulate each other in the effects of HQ on BMSCs in order to ameliorate the altered function of BMSCs.

The role of short-chain fatty acids in cancer prevention and cancer treatment

Short-chain fatty acids (SCFAs) are microbial metabolites in the gut that may play a role in cancer prevention and treatment. They affect the metabolism of both normal and cancer cells, regulating various cellular energetic processes. SCFAs also inhibit histone deacetylases, which are targets for cancer therapy. The three main SCFAs are acetate, propionate, and butyrate, which are transported into cells through specific transporters. SCFAs may enhance the efficacy of chemotherapeutic agents and modulate immune cell metabolism, potentially reprogramming the tumor microenvironment. Although SCFAs and SCFA-generating microbes enhance therapeutic efficacy of several forms of cancer therapy, published data also support the opposing viewpoint that SCFAs mitigate the efficacy of some cancer therapies. Therefore, the relationship between SCFAs and cancer is more complex, and this review discusses some of these aspects. Clearly, further research is needed to understand the role of SCFAs, their mechanisms, and applications in cancer prevention and treatment.

Rituximab induces ferroptosis and RSL3 overcomes rituximab resistance in diffuse large B-cell lymphoma cells

Diffuse large B-cell lymphoma (DLBCL) is the most common malignant lymphoma in adults, and the use of rituximab has greatly improved the survival of DLBCL patients. Currently, the first-line treatment regimen for DLBCL is still rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP), which significantly improves outcomes for DLBCL patients. However, a percentage of patients still experience refractory or relapsed disease. Since Dr. Brent R Stockwell proposed ferroptosis in 2012, Roudkenar, M. H. Roushandeh, A. M. Valashedi, M. R. and others proved the importance of ferroptosis in cancer drug resistance. The purpose of this study was to elucidate whether rituximab could exert anticancer effects on DLBCL cells by promoting ferroptosis. Cell viability was assessed using the Cell Counting Kit-8. The results showed that rituximab exposure induced ferroptosis in OCI-LY1 cells. However, combination with ferroptosis inhibitor ferrostatin (Fer-1) rescued ferroptosis-induced injury, indicating that ferroptosis plays a key role in rituximab-induced cell death. Western blotting was performed to detect the levels of specific ferroptosis-associated proteins in DLBCL. Moreover, GSH depletion and MDA upregulation was assessed using GSH assays and MDA assay kits in rituximab-treated OCI-LY1 cells. In addition, rituximab failed to induce ferroptosis in rituximab-resistant cell lines. Treatment with RSL3 enhanced the effects of rituximab on DLBCL cells by inhibiting cell viability. In conclusion, we report for the first time that rituximab induces ferroptosis in lymphoma cells, at least partially through the SLC7A11/GPX4 axis. We also identify targeting ferroptosis as a promising therapeutic option for both sensitive cells and resistant cells in the treatment of DLBCL.

Resistance to FOXM1 inhibitors in breast cancer is accompanied by impeding ferroptosis and apoptotic cell death

PURPOSE

Cancer treatments often become ineffective because of acquired drug resistance. To characterize changes in breast cancer cells accompanying development of resistance to inhibitors of the oncogenic transcription factor, FOXM1, we investigated the suppression of cell death pathways, especially ferroptosis, in FOXM1 inhibitor-resistant cells. We also explored whether ferroptosis activators can synergize with FOXM1 inhibitors and can overcome FOXM1 inhibitor resistance.

METHODS

In estrogen receptor-positive and triple-negative breast cancer cells treated with FOXM1 inhibitor NB73 and ferroptosis activators dihydroartemisinin and JKE1674, alone and in combination, we measured suppression of cell viability, motility, and colony formation, and monitored changes in gene and protein pathway expressions and mitochondrial integrity.

RESULTS

Growth suppression of breast cancer cells by FOXM1 inhibitors is accompanied by increased cell death and alterations in mitochondrial morphology and metabolic activity. Low doses of FOXM1 inhibitor strongly synergize with ferroptosis inducers to reduce cell viability, migration, colony formation, and expression of proliferation-related genes, and increase intracellular Fe+2 and lipid peroxidation, markers of ferroptosis. Acquired resistance to FOXM1 inhibition is associated with increased expression of cancer stem-cell markers and proteins that repress ferroptosis, enabling cell survival and drug resistance. Notably, resistant cells are still sensitive to growth suppression by low doses of ferroptosis activators, effectively overcoming the acquired resistance.

CONCLUSION

Delineating changes in viability and cell death pathways that can overcome drug resistance should be helpful in determining approaches that might best prevent or reverse resistance to therapeutic targeting of FOXM1 and ultimately improve patient clinical outcomes.

Delay the progression of glucocorticoid-induced osteoporosis: Fraxin targets ferroptosis via the Nrf2/GPX4 pathway

Glucocorticoid-induced osteoporosis (GIOP) commonly accelerates bone loss, increasing the risk of fractures and osteonecrosis more significantly than traditional menopausal osteoporosis. The extracellular environment influenced by glucocorticoids heightens fracture and osteonecrosis risks. Fraxin (Fra), a key component of the traditional Chinese herbal remedy Cortex Fraxini, is known for its wide-ranging pharmacological effects, but its impact on GIOP remains unexplored. This investigation aims to delineate the effects and underlying mechanisms of Fra in combating dexamethasone (Dex)-induced ferroptosis and GIOP. We established a mouse model of GIOP via intraperitoneal injections of Dex and cultured osteoblasts with Dex treatment for in vitro analysis. We evaluated the impact of Fra on Dex-treated osteoblasts through assays such as C11-BODIPY and FerroOrange staining, mitochondrial functionality tests, and protein expression analyses via Western blot and immunofluorescence. The influence of Fra on bone microarchitecture of GIOP in mice was assessed using microcomputerized tomography, hematoxylin and eosin staining, double-labeling with Calcein-Alizarin Red S, and immunohistochemistry at imaging and histological levels. Based on our data, Fra prevented Dex-induced ferroptosis and bone loss. In vitro, glutathione levels increased and malondialdehyde, lipid peroxidation, and mitochondrial reactive oxygen species decreased. Fra treatment also increases nuclear factor erythroid 2-related factor 2 (Nrf2), glutathione peroxidase 4 (GPX4), and COL1A1 expression and promotes bone formation. To delve deeper into the mechanism, the findings revealed that Fra triggered the activation of Nrf2/GPX4 signaling. Moreover, the use of siRNA-Nrf2 blocked the beneficial effect of Fra in osteoblasts cultivated with Dex. Fra effectively combats GIOP by activating the Nrf2/GPX4 signaling pathway to inhibit ferroptosis.

Gas6/AXL Alleviates Hepatic Ischemia/Reperfusion Injury by Inhibiting Ferroptosis via the PI3K/AKT Pathway

BACKGROUND

Hepatic ischemia/reperfusion (I/R) injury is a major cause of complications in clinical liver surgery. AXL receptor tyrosine kinase (AXL) is a member of the TAM receptor tyrosine kinase family (TYRO3, AXL, and MERTK). Our previous study has shown that AXL expression was markedly upregulated in liver transplantation patients. However, the underlying mechanism of AXL in hepatic I/R injury remains unclear.

METHODS

A mouse liver warm I/R model and a primary hepatocyte hypoxia/reoxygenation model were established to investigate the role of AXL activation and ferroptosis in hepatic I/R injury by pretreating with recombinant mouse growth arrest-specific protein 6 (AXL activator) or R428 (AXL inhibitor). Moreover, we used LY294002 (phosphatidylinositol 3-kinase [PI3K] inhibitor) to evaluate the relationship between the PI3K/AKT (the Ser and Thr kinase AKT) pathway and ferroptosis in hepatic I/R injury.

RESULTS

Hepatic I/R injury decreased phosphorylation AXL expression and enhanced ferroptosis in liver transplantation patients and hepatic I/R-subjected mice. AXL activation attenuated lipid peroxidation and ferroptosis in hepatic I/R injury in vivo and in vitro. Inhibition of AXL activation exacerbated liver pathological damage and liver dysfunction, as well as iron accumulation and lipid peroxidation in hepatic I/R injury. Mechanistically, activated growth arrest-specific protein 6/AXL and its downstream PI3K/AKT signaling pathway inhibited ferroptosis during hepatic I/R injury.

CONCLUSIONS

AXL activation protects against hepatic I/R injury by preventing ferroptosis through the PI3K/AKT pathway. This study is the first investigation on the AXL receptor and ferroptosis, and activating AXL to mitigate ferroptosis may be an innovative therapeutic strategy to combat hepatic I/R injury.

Activation of autophagy, paraptosis, and ferroptosis by micheliolide through modulation of the MAPK signaling pathway in pancreatic and colon tumor cells

Micheliolide (MCL), a naturally occurring sesquiterpene lactone, has demonstrated significant anticancer properties through the induction of various programmed cell death mechanisms. This study aimed to explore MCL's effects on autophagy, paraptosis, and ferroptosis in pancreatic and colon cancer cells, along with its modulation of the MAPK signaling pathway. MCL was found to substantially suppress cell viability in these cancer cells, particularly in MIA PaCa-2 and HT-29 cell lines. The study identified that MCL induced autophagy by enhancing the levels of autophagy markers such as Atg7, p-Beclin-1, and Beclin-1, which was attenuated by the autophagy inhibitor 3-MA. Furthermore, MCL was found to facilitate paraptosis, indicated by decreased Alix and in-creased ATF4 and CHOP levels. It also promoted ferroptosis, as demonstrated by the reduced expression of SLC7A11, elevated TFRC levels, and increased intracellular iron. Additionally, MCL activated the MAPK signaling pathway, marked by the phosphorylation of JNK, p38, and ERK, linked with an increase in ROS production that is vital in regulating these cell death mechanisms. These findings propose that MCL is a versatile anticancer agent, capable of activating various cell death pathways by modulating MAPK signaling and ROS levels. These results emphasize the therapeutic promise of MCL in treating cancer, pointing to the necessity of further in vivo investigations to confirm these effects and determine its potential clinical uses.

Cellular and molecular mechanisms of gastrointestinal cancer liver metastases and drug resistance

Distant metastases and drug resistance account for poor survival of patients with gastrointestinal (GI) malignancies such as gastric cancer, pancreatic cancer, and colorectal cancer. GI cancers most commonly metastasize to the liver, which provides a unique immunosuppressive tumour microenvironment to support the development of a premetastatic niche for tumor cell colonization and metastatic outgrowth. Metastatic tumors often exhibit greater resistance to drugs than primary tumors, posing extra challenges in treatment. The liver metastases and drug resistance of GI cancers are regulated by complex, intertwined, and tumor-dependent cellular and molecular mechanisms that influence tumor cell behavior (e.g. epithelial-to-mesenchymal transition, or EMT), tumor microenvironment (TME) (e.g. the extracellular matrix, cancer-associated fibroblasts, and tumor-infiltrating immune cells), tumor cell-TME interactions (e.g. through cytokines and exosomes), liver microenvironment (e.g. hepatic stellate cells and macrophages), and the route and mechanism of tumor cell dissemination (e.g. circulating tumor cells). This review provides an overview of recent advances in the research on cellular and molecular mechanisms that regulate liver metastases and drug resistance of GI cancers. We also discuss recent advances in the development of mechanism-based therapy for these GI cancers. Targeting these cellular and molecular mechanisms, either alone or in combination, may potentially provide novel approaches to treat metastatic GI malignancies.

USP22 promotes gefitinib resistance and inhibits ferroptosis in non-small cell lung cancer by deubiquitination of MDM2

BACKGROUND

The emergence of chemoresistance markedly compromised the treatment efficiency of human cancer, including non-small cell lung cancer (NSCLC). In the present study, we aimed to explore the effects of ubiquitin-specific peptidase 22 (USP22) and murine double minute 2 (MDM2) in gefitinib resistance in NSCLC.

METHODS

Immunohistochemistry (IHC) assay, quantitative real-time polymerase chain reaction (qRT-PCR) assay and western blot assay were carried out to determine the expression of USP22 and MDM2. Transwell assay and flow cytometry analysis were performed to evaluate cell migration and apoptosis. Cell Counting Kit-8 (CCK-8) assay was employed to assess gefitinib resistance. The phenomenon of ferroptosis was estimated by related commercial kits. The oxidized C11-BODIPY fluorescence intensity by C11-BODIPY staining. The relation between USP22 and MDM2 was analyzed by ubiquitination assay and co-immunoprecipitation (Co-IP) assay.

RESULTS

USP22 was abnormally upregulated in NSCLC tissues and cells, and USP22 silencing markedly repressed NSCLC cell migration and facilitated apoptosis and ferroptosis. Moreover, our results indicated that ferroptosis could enhance the suppressive effect of gefitinib on NSCLC cells. Besides, USP22 overexpression enhanced gefitinib resistance and ferroptosis protection in NSCLC cells. Mechanically, USP22 stabilized MDM2 and regulated MDM2 expression through deubiquitination of MDM2. MDM2 deficiency partially restored the effects of USP22 on gefitinib resistance and ferroptosis in NSCLC cells. Of note, we validated the promotional effect of USP22 on gefitinib resistance in NSCLC in vivo through establishing the murine xenograft model.

CONCLUSION

USP22/MDM2 promoted gefitinib resistance and inhibited ferroptosis in NSCLC, which might offer a novel strategy for overcoming gefitinib resistance in NSCLC.

Ferroptosis in Parkinson's disease -- The iron-related degenerative disease

Parkinson's disease (PD) is a prevalent and advancing age-related neurodegenerative disorder, distinguished by the degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNpc). Iron regional deposit in SNpc is a significant pathological characteristic of PD. Brain iron homeostasis is precisely regulated by iron metabolism related proteins, whereas disorder of these proteins can damage neurons and glial cells in the brain. Additionally, growing studies have reported iron metabolism related proteins are involved in the ferroptosis progression in PD. However, the effect of these proteins in the ferroptosis of PD has not been systematically summarized. This review focuses on the roles of iron metabolism related proteins in the ferroptosis of PD. Finally, we put forward the iron early diagnosis according to the observation of iron deposits in the brain and showed the recent advances in iron chelation therapy in PD.

Natural product mitigation of ferroptosis in platinum-based chemotherapy toxicity: targeting the underpinning oxidative signaling pathways

OBJECTIVES

Platinum-based anticancer chemotherapy (PAC) represents a cornerstone in cancer treatment, retaining its status as the gold standard therapy. However, PAC's efficacy is countered by significant toxicities, such as nephrotoxicity, ototoxicity, and neurotoxicity. Recent studies have linked these toxicities to ferroptosis, characterized by iron accumulation, reactive oxygen species generation, and lipid peroxidation. This review explores the mechanisms underlying PAC-induced toxicities, focusing on the involvement of ferroptosis with three major PAC drugs-cisplatin, carboplatin, and oxaliplatin. Further, we provide a comprehensive analysis of the natural product mitigation of PAC-induced ferroptotic toxicity.

KEY FINDINGS

The mechanistic role of ferroptosis in cisplatin- and oxaliplatin-induced toxicities has been investigated, while studies on carboplatin-induced ferroptotic toxicities are lacking. Natural compounds targeting molecular pathways of ferroptosis have been explored to mitigate PAC-induced ferroptotic toxicity.

CONCLUSION

While ferroptosis in cisplatin- and oxaliplatin-induced toxicities has been investigated, there remains a notable dearth of studies examining its involvement in carboplatin-induced toxicities. Hence, further exploration is warranted to define the role of ferroptosis in carboplatin-induced toxicities, and its further mitigation. Moreover, in-depth mechanistic evaluation is necessary to establish natural products evaluated against PAC-induced ferroptosis, as PAC adjuvants.

FMRP protects breast cancer cells from ferroptosis by promoting SLC7A11 alternative splicing through interacting with hnRNPM

Ferroptosis is a unique modality of regulated cell death that is driven by iron-dependent phospholipid peroxidation. N6-methyladenosine (m6A) RNA modification participates in varieties of cellular processes. However, it remains elusive whether m6A reader Fragile X Mental Retardation Protein (FMRP) are involved in the modulation of ferroptosis in breast cancer (BC). In this study, we found that FMRP expression was elevated and associated with poor prognosis and pathological stage in BC patients. Overexpression of FMRP induced ferroptosis resistance and exerted oncogenic roles by positively regulating a critical ferroptosis defense gene SLC7A11. Mechanistically, upregulated FMRP catalyzes m6A modification of SLC7A11 mRNA and further influences the SLC7A11 translation through METTL3-dependent manner. Further studies revealed that FMRP interacts with splicing factor hnRNPM to recognize the splice site and then modulated the exon skip splicing event of SLC7A11 transcript. Interestingly, SLC7A11-S splicing variant can effectively promote FMRP overexpression-induced ferroptosis resistance in BC cells. Moreover, our clinical data suggested that FMRP/hnRNPM/SLC7A11 expression were significantly increased in the tumor tissues, and this signal axis was important evaluation factors closely related to the worse survival and prognosis of BC patients. Overall, our results uncovered a novel regulatory mechanism by which high FMRP expression protects BC cells from undergoing ferroptosis. Targeting the FMRP-SLC7A11 axis has a dual effect of inhibiting ferroptosis resistance and tumor growth, which could be a promising therapeutic target for treating BC.

Exploring the roles and molecular mechanisms of RNA binding proteins in the sorting of noncoding RNAs into exosomes during tumor progression

BACKGROUND

RNA binding proteins (RBPs) play a role in sorting non-coding RNAs (ncRNAs) into exosomes. These ncRNAs, carried by exosomes, are involved in regulating various aspects of tumor progression, including metastasis, angiogenesis, control of the tumor microenvironment, and drug resistance. Recent studies have emphasized the importance of the RBP-ncRNA-exosome mechanism in tumor regulation.

AIM OF REVIEW

This comprehensive review aims to explore the RBP-ncRNA-exosome mechanism and its influence on tumor development. By understanding this intricate mechanism provides novel insights into tumor regulation and may lead to innovative treatment strategies in the future.

KEY SCIENTIFIC CONCEPTS OF REVIEW

The review discusses the formation of exosomes and the complex relationships among RBPs, ncRNAs, and exosomes. The RBP-ncRNA-exosome mechanism is shown to affect various aspects of tumor biology, including metastasis, multidrug resistance, angiogenesis, the immunosuppressive microenvironment, and tumor progression. Tumor development relies on the transmission of information between cells, with RBPs selectively mediating sorting of ncRNAs into exosomes through various mechanisms, which in turn carry ncRNAs to regulate RBPs. The review also provides an overview of potential therapeutic strategies, such as targeted drug discovery and genetic engineering for modifying therapeutic exosomes, which hold great promise for improving cancer treatment.

SNORA71A Downregulation Enhances Gemcitabine Sensitivity in Gallbladder Cancer Cells by Inducing Ferroptosis Through Inhibiting the AKT/NRF2/GPX4 Pathway

Previous findings have indicated a marked upregulation of SNORA71A in gallbladder cancer (GBC) tissues compared to normal samples. However, the precise role and molecular mechanisms of SNORA71A in GBC remain largely unknown. Moreover, gemcitabine (GEM) drug resistance has been found to lead to unfavorable outcomes and recurrence in GBC patients. Therefore, this study aims to investigate the impact of SNORA71A on GBC and explore its potential effects on the sensitivity of GBC cells to GEM. RT-qPCR was conducted to assess SNORA71A level in matched normal and GBC tissues. Cell proliferation was examined through CCK-8 and 5-ethynyl-2'-deoxyuridine (EdU) assays. Additionally, the expression of proteins in GBC cells was analyzed using western blot assay. The level of SNORA71A was notably higher in GBC tissues relative to normal tissues. SNORA71A overexpression led to increased GBC cell proliferation and invasion. Conversely, SNORA71A deficiency strongly suppressed GBC cell proliferation and invasion and triggered cell apoptosis and ferroptosis. Additionally, downregulation of SNORA71A obviously enhanced the antiproliferative and anti-invasive effects of GEM on GBC cells, whereas these changes were reversed by inhibiting ferroptosis. Furthermore, deficiency of SNORA71A further augmented the GEM-induced downregulation of p-Akt, Nrf2, and GPX4 in NOZ cells; however, these effects were reversed by ferroptosis inhibition. Collectively, these findings suggested that downregulation of SNORA71A may increase the sensitivity of GBC cells to GEM by triggering ferroptosis through inhibiting the AKT/NRF2/GPX4 signaling pathway.

Targeting ferroptosis in autoimmune diseases: Mechanisms and therapeutic prospects

Ferroptosis is a form of regulated cell death that relies on iron and exhibits unique characteristics, including disrupted iron balance, reduced antioxidant defenses, and abnormal lipid peroxidation. Recent research suggests that ferroptosis is associated with the onset and progression of autoimmune disorders such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), inflammatory bowel disease (IBD), and multiple sclerosis (MS). However, the precise effects and molecular mechanisms remain incompletely understood. This article presents an overview of how ferroptosis mechanisms contribute to the development and advancement of autoimmune diseases, as well as the involvement of various immune cells in linking ferroptosis to autoimmune conditions. It also explores potential drug targets within the ferroptosis pathway and recent advancements in therapeutic approaches aimed at preventing and treating autoimmune diseases by targeting ferroptosis. Lastly, the article discusses the challenges and opportunities in utilizing ferroptosis as a potential therapeutic avenue for autoimmune disorders.

A Nanoreactor Based on Metal-Organic Frameworks With Triple Synergistic Therapy for Hepatocellular Carcinoma

The transformation of monotherapy into multimodal combined targeted therapy to fully exploit synergistic efficacy is of increasing interest in tumor treatment. In this work, a novel nanodrug-carrying platform based on iron-based MOFs, which is loaded with doxorubicin hydrochloride (DOX), dihydroartemisinin (DHA), and glucose oxidase (GOx), and concurrently covalently linked to the photosensitizer 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (TCPP) in polydopamine (PDA)-encapsulated MIL-101(Fe) (denoted as MIL-101(Fe)-DOX-DHA@TCPP/GOx@PDA, MDDTG@P), is successfully developed. Upon entering the tumor microenvironment, MDDTG@P catalyzes the hydrogen peroxide (H2O2) into hydroxyl radicals (·OH) and depletes glutathione (GSH); thus, exerting the role of chemodynamic therapy (CDT). The reduced Fe2+ can also activate DHA, further expanding CDT and promoting tumor cell apoptosis. The introduced GOx will rapidly consume glucose and oxygen (O2) in the tumor; while, replenishing H2O2 for Fenton reaction, starving the cancer cells; and thus, realizing starvation and chemodynamic therapy. In addition, the covalent linkage of TCPP endows MDDTG@P with good photodynamic therapeutic (PDT) properties. Therefore, this study develops a nanocarrier platform for triple synergistic chemodynamic/photodynamic/starvation therapy, which has promising applications in the efficient treatment of tumors.

Silencing CCT3 induces ferroptosis through the NOD1-NF-κB signaling pathway in bladder cancer

Bladder cancer (BCa) is a lethal malignancy of the urinary system and exhibits a poor prognosis. Chaperonin-containing tailless complex polypeptide 1 subunit 3 (CCT3) acts as an oncogene in various tumors, whereas its effect on BCa remains unknown. We identified the ferroptosis-associated differentially expressed genes through bioinformatic analysis and selected CCT3 for further verification. The levels of cell viability, apoptosis, migration, invasion, and proliferation were measured to clarify the effect of silencing CCT3 on BCa cells. Then we evaluated the role of CCT3 knockdown in vivo. Ferroptosis was assessed by the expression detection of the ferroptosis-related proteins. The underlying mechanism was predicted by RNA sequencing and verified by an agonist for nucleotide-binding and oligomerization domain 1 (NOD1). Western blotting was conducted to detect the protein expression of NOD1, nuclear factor kappa B (NF-κB) inhibitor alpha (IκBα), and phospho-IκBα (p-IκBα). In vitro, down-regulation of CCT3 suppressed the cell viability, migration, invasion, and proliferation, as well as induced apoptosis of BCa cells. In vivo, silencing CCT3 elevated the body weight of mice and suppressed the BCa progression. In addition, CCT3 knockdown could induce ferroptosis in vitro and in vivo. CCT3 knockdown suppressed the expression of NOD1 and p-IκBα/IκBα and the NOD1 agonist could reverse the effect of CCT3 suppression on BCa in vitro and in vivo. In summary, our findings demonstrate that silencing CCT3 inhibits BCa via induction of ferroptosis and suppression of the NOD1-NF-κB pathway.

Reverse magnetic resonance tuning nanoplatform with heightened sensitivity for non-invasively multiscale visualizing ferroptosis-based tumor sensitization therapy

Ferroptosis-based therapy has garnered considerable attention for its ability to kill drug-resistant cancer cells. Consequently, it holds great significance to assess the therapeutic outcomes by monitoring ferroptosis-related biomarkers, which enables the provision of real-time pathological insights into disease progression. Nevertheless, conventional imaging technology suffers from limitations including reduced sensitivity and difficulty in achieving real-time precise monitoring. Here, we report a tumor acidic-microenvironment-responsive nanoplatform with "Reverse Magnetic Resonance Tuning (ReMRT)" property and effective combined chemodynamic therapy (CDT) through the loading of chemotherapeutic drugs. This reverse MR mapping change is correlated with iron ion, reactive oxygen species (ROS) generation and drug release, etc., contributing to the precise monitoring of chemo-CDT effectiveness. Furthermore, the ReMRT nanoplatform presents as a highly efficacious combined chemo-CDT agent, and when this nanoplatform is used in conjunction with the "Area Reconstruction" method, it can afford a significant sensitivity (95.1-fold) in multiscale visualization of therapeutic, compared with the conventional MR R1/R2 values. The high-sensitive biological quantitative imaging provides a novel strategy for MR-guided multiscale dynamic tumor-related ferroptosis therapy.

NPR1 promotes cisplatin resistance by inhibiting PARL-mediated mitophagy-dependent ferroptosis in gastric cancer

Cisplatin-based chemotherapy serves as the standard of care for individuals with advanced stages of gastric cancer. Nevertheless, the emergence of chemoresistance in GC has detrimental impacts on prognosis, yet the underlying mechanisms governing this phenomenon remain elusive. Level of mitophagy and ferroptosis of GC cells were detected by fluorescence, flow cytometry, GSH, MDA, Fe2+ assays, and to explore the specific molecular mechanisms between NPR1 and cisplatin resistance by performing western blot and coimmunoprecipitation (co-IP) assays. These results indicates that NPR1 positively correlated with cisplatin-resistance and played a crucial part in conferring resistance to cisplatin in gastric cancer cells. Mechanistically, NPR1 affected levels of mitophagy and ferroptosis in human cisplatin-resistance GC cells with cisplatin treatment. Specifically, NPR1 inhibited mitophagy-dependent ferroptosis by reducing the ubiquitination-mediated degradation of PARL; moreover, NPR1 promoted PARL stabilization by disrupting the PARL-MARCH8 complex, which ultimately led to the development of chemoresistance in GC cells. Considering our findings, NPR1 appears to play an important role in chemotherapy for GC. NPR1 could potentially be used to overcome chemotherapy resistance.

A prospective therapeutic strategy: GPX4-targeted ferroptosis mediators

As a crucial regulator of oxidative homeostasis, seleno-protein glutathione peroxidase 4 (GPX4) represents the primary defense system against ferroptosis, making it a promising target with important clinical application prospects. From the discovery of covalent and allosteric sites in GPX4, substantial advancements in GPX4-targeted small molecules have been made through diverse discovery and design strategies in recent years. Moreover, as an emerging hotspot in drug development, seleno-organic compounds can functionally mimic GPX4 to reduce hydroperoxides. To facilitate the further development of selective ferroptosis mediators as potential pharmaceutical agents, this review comprehensively covers all GPX4-targeted small molecules, including inhibitors, degraders, and activators. In addition, seleno-organic compounds as GPX mimics are also included. We also provide perspectives regarding challenges and future research directions in this field.

Combined targeting of GPX4 and BCR-ABL tyrosine kinase selectively compromises BCR-ABL+ leukemia stem cells

BACKGROUND

In the ongoing battle against BCR-ABL+ leukemia, despite significant advances with tyrosine kinase inhibitors (TKIs), the persistent challenges of drug resistance and the enduring presence of leukemic stem cells (LSCs) remain formidable barriers to achieving a cure.

METHODS

In this study, we demonstrated that Disulfiram (DSF) induces ferroptosis to synergize with TKIs in inhibiting BCR-ABL+ cells, particularly targeting resistant cells and LSCs, using cell models, mouse models, and primary cells from patients. We elucidated the mechanism by which DSF promotes GPX4 degradation to induce ferroptosis through immunofluorescence, co-immunoprecipitation (CO-IP), RNA sequencing, lipid peroxidation assays, and rescue experiments.

RESULTS

Here, we present compelling evidence elucidating the sensitivity of DSF, an USA FDA-approved drug for alcohol dependence, towards BCR-ABL+ cells. Our findings underscore DSF's ability to selectively induce a potent cytotoxic effect on BCR-ABL+ cell lines and effectively inhibit primary BCR-ABL+ leukemia cells. Crucially, the combined treatment of DSF with TKIs selectively eradicates TKI-insensitive stem cells and resistant cells. Of particular note is DSF's capacity to disrupt GPX4 stability, elevate the labile iron pool, and intensify lipid peroxidation, ultimately leading to ferroptotic cell death. Our investigation shows that BCR-ABL expression induces alterations in cellular iron metabolism and increases GPX4 expression. Additionally, we demonstrate the indispensability of GPX4 for LSC development and the initiation/maintenance of BCR-ABL+ leukemia. Mechanical analysis further elucidates DSF's capacity to overcome resistance by reducing GPX4 levels through the disruption of its binding with HSPA8, thereby promoting STUB1-mediated GPX4 ubiquitination and subsequent proteasomal degradation. Furthermore, the combined treatment of DSF with TKIs effectively targets both BCR-ABL+ blast cells and drug-insensitive LSCs, conferring a significant survival advantage in mouse models.

CONCLUSION

In summary, the dual inhibition of GPX4 and BCR-ABL presents a promising therapeutic strategy to synergistically target blast cells and drug-insensitive LSCs in patients, offering potential avenues for advancing leukemia treatment.

Progress in research of ferroptosis in gastrointestinal tumors

Ferroptosis is a non-apoptotic and oxidation-damaged regulated cell death caused by iron accumulation, lipid peroxidation, and subsequent plasma membrane rupture. Ferroptosis is the main cause of tissue damage caused by iron overload and lipid peroxidation. With the deepening of the research in recent years, the understanding of the occurrence and treatment of tumors has made a major breakthrough, which brings new strategies for anti-cancer treatment. This paper reviews the relationship between ferroptosis and gastrointestinal tumors, the research of ferroptosis in cancer prevention and treatment, and the role of ferroptosis in the prevention and treatment of gastrointestinal tumors.

Genetic profile of ferroptosis in non-small cell lung carcinoma and pharmaceutical options for ferroptosis induction

Lung cancer (LC) is the leading cause of cancer-related deaths and the second most commonly diagnosed malignancy worldwide. Lung adenocarcinoma (LUAD) and lung squamous cell LC (LUSCC) are the most common subtypes of non-small cell LC (NSCLC). Early diagnosis of LC can be challenging due to a lack of biomarkers. The overall survival (OS) of patients with NSCLC is still poor despite the enormous efforts that have been made to develop novel treatments. Understanding fundamental molecular and genetic mechanisms is necessary to develop new therapeutic approaches for NSCLC. A recently identified type of programmed cell death known as ferroptosis is one potential approach. Ferroptosis causes oxidative damage and the death of cancerous cells by peroxidizing unsaturated phospholipids and accumulating reactive oxygen species (ROS) in an iron-dependent manner. Ferroptosis-related gene (FRG) signatures have recently been evaluated for their ability to predict patient OS and prognosis. These analyses show FRGs are involved in cancer progression, and may serve as promising biomarkers for tumor diagnosis and therapy. Moreover, we summarize the current pharmaceutical options of ferroptosis induction and their underlying molecular mechanism in LC. Therefore, this review aims to provide a comprehensive summary of FRG-based prognostic models, their associated metabolic and signaling pathways, and promising therapeutic options for ferroptosis induction in NSCLC.

SLC7A9 suppression increases chemosensitivity by inducing ferroptosis via the inhibition of cystine transport in gastric cancer

BACKGROUND

SLC7A9 is responsible for the exchange of dibasic amino acids and cystine (influx) for neutral amino acids (efflux). Cystine/cysteine transport is related to ferroptosis.

METHODS

Sanger sequencing detected TP53 status of cancer cells. Transcriptomic sequencing and untargeted metabolome profiling were used to identify differentially expressed genes and metabolites, respectively, upon SLC7A9 overexpression. CCK8, cell clonality, and EdU assays were used to observe cell proliferation. Cystine probes, glutathione (GSH) probes, and lipid ROS probes were used to examine cystine, GSH, and lipid ROS levels. 13C metabolic flow assays were used to monitor cellular cystine and GSH metabolism. Patient-derived organoids (PDO), immunocompetent MFC mice allograft models and patient-derived xenograft (PDX) models were used to evaluate SLC7A9 impact on chemotherapeutic response and to observe therapeutic effect of SLC7A9 knockdown.

FINDINGS

Elevated SLC7A9 expression levels in gastric cancer cells were attributed to p53 loss. SLC7A9 knockdown suppressed the proliferation and increased the chemotherapy sensitivity of the cells. Chemotherapy was more effective in PDX and immunocompetent mice models upon SLC7A9 knockdown. Differentially expressed genes and metabolites between the SLC7A9 overexpression and control groups were associated with ferroptosis and GSH metabolism. SLC7A9 knockdown reduced cystine transport into cells, hampered intracellular cystine and GSH metabolic flow, decreased GSH synthesis, and increased lipid ROS levels in gastric cancer cells. Erastin was more effective at inducing ferroptosis in PDO and PDX models upon SLC7A9 knockdown.

INTERPRETATION

SLC7A9 promotes gastric cancer progression by acting as a suppressor of ferroptosis, independent of SLC7A11, which is negatively regulated by p53.

FUNDING

This work was supported by National Natural Science Foundation of China, Innovation Promotion Program of NHC and Shanghai Key Labs SIBPT, and Shanghai Academy of Science & Technology.

EIF2S1 Silencing Impedes Neuroblastoma Development Through GPX4 Inactivation and Ferroptosis Induction

Background: Neuroblastoma (NB) is one of the most devastating malignancies in children, accounting for a high mortality rate due to limited treatment options. This study is aimed at elucidating the role of the ferroptosis-related EIF2S1 gene in NB pathogenesis and exploring its potential as a therapeutic target. Methods: We conducted comprehensive bioinformatics analyses utilizing the FerrDb database and NB-related transcriptomics data to investigate the role of EIF2S1 in NB. Changes in EIF2S1 expression were subsequently validated in NB tissues and cell lines. Loss-of-function experiments were performed in SK-N-SH and IMR-32 cell lines through shRNA-mediated EIF2S1 knockdown. The impact of EIF2S1 knockdown on the tumorigenesis of SK-N-SH cells was assessed in nude mice. Results: Bioinformatics analyses revealed a significant association between elevated EIF2S1 expression and poor prognosis in NB patients. The increased levels of EIF2S1 expression were confirmed in NB tissues and cancerous cell lines. Furthermore, EIF2S1 overexpression was linked to translational regulation and immune cell infiltration modulation. Silencing of EIF2S1 resulted in the suppression of cell proliferation, migration, and tumorigenicity in NB cells. Additionally, EIF2S1 knockdown led to an accumulation of iron and oxidative stress, as well as a reduction in GPX4 and SLC7A11 expression. Conclusion: Our findings indicate that EIF2S1 appears to facilitate the progression of NB by protecting tumor cells from ferroptosis through modulating GPX4 and SLC7A11 expression. Consequently, EIF2S1 may serve as a potential therapeutic target for the management of NB.

Cold and hot tumors: from molecular mechanisms to targeted therapy

Immunotherapy has made significant strides in cancer treatment, particularly through immune checkpoint blockade (ICB), which has shown notable clinical benefits across various tumor types. Despite the transformative impact of ICB treatment in cancer therapy, only a minority of patients exhibit a positive response to it. In patients with solid tumors, those who respond well to ICB treatment typically demonstrate an active immune profile referred to as the "hot" (immune-inflamed) phenotype. On the other hand, non-responsive patients may exhibit a distinct "cold" (immune-desert) phenotype, differing from the features of "hot" tumors. Additionally, there is a more nuanced "excluded" immune phenotype, positioned between the "cold" and "hot" categories, known as the immune "excluded" type. Effective differentiation between "cold" and "hot" tumors, and understanding tumor intrinsic factors, immune characteristics, TME, and external factors are critical for predicting tumor response and treatment results. It is widely accepted that ICB therapy exerts a more profound effect on "hot" tumors, with limited efficacy against "cold" or "altered" tumors, necessitating combinations with other therapeutic modalities to enhance immune cell infiltration into tumor tissue and convert "cold" or "altered" tumors into "hot" ones. Therefore, aligning with the traits of "cold" and "hot" tumors, this review systematically delineates the respective immune characteristics, influencing factors, and extensively discusses varied treatment approaches and drug targets based on "cold" and "hot" tumors to assess clinical efficacy.

Ironing Out the Mechanism of gp130 Signaling

gp130 functions as a shared signal-transducing subunit not only for interleukin (IL)-6 but also for eight other human cytokine receptor complexes. The IL-6 signaling pathway mediated through gp130 encompasses classical, trans, or cluster signaling, intricately regulated by a diverse array of modulators affecting IL-6, its receptor, and gp130. Currently, only a limited number of small molecule antagonists and agonists for gp130 are known. This review aims to comprehensively examine the current knowledge of these modulators and provide insights into their pharmacological properties, particularly in the context of cancer and other diseases. Notably, the prominent gp130 modulators SC144, bazedoxifene, and raloxifene are discussed in detail, with a specific focus on the discovery of SC144's iron-chelating properties. This adds a new dimension to the understanding of its pharmacological effects and therapeutic potential in conditions where iron homeostasis is significant. Our bioinformatic analysis of gp130 and genes related to iron homeostasis reveals insightful correlations, implicating the role of iron in the gp130 signaling pathway. Overall, this review contributes to the evolving understanding of gp130 modulation and its potential therapeutic applications in various disease contexts. SIGNIFICANCE STATEMENT: This perspective provides a timely and comprehensive analysis of advancements in gp130 signaling research, emphasizing the therapeutic implications of the currently available modulators. Bioinformatic analysis demonstrates potential interplay between gp130 and genes that regulate iron homeostasis, suggesting new therapeutic avenues. By combining original research findings with a broader discussion of gp130's therapeutic potential, this perspective significantly contributes to the field.

Navigating the complexities of cell death: Insights into accidental and programmed cell death

Cell death is a critical biological phenomenon that can be categorized into accidental cell death (ACD) and programmed cell death (PCD), each exhibiting distinct signaling, mechanistic and morphological characteristics. This paper provides a comprehensive overview of seven types of ACD, including coagulative, liquefactive, caseous, fat, fibrinoid, gangrenous and secondary necrosis, discussing their pathological implications in conditions such as ischemia and inflammation. Additionally, we review eighteen forms of PCD, encompassing autophagy, apoptosis, necroptosis, pyroptosis, paraptosis, ferroptosis, anoikis, entosis, NETosis, eryptosis, parthanatos, mitoptosis, and newly recognized types such as methuosis, autosis, alkaliptosis, oxeiptosis, cuprotosis and erebosis. The implications of these cell death modalities for cellular processes, development, and disease-particularly in the context of neoplastic and neurodegenerative disorders-are also covered. Furthermore, we explore the crosstalk between various forms of PCD, emphasizing how apoptotic mechanisms can influence pathways like necroptosis and pyroptosis. Understanding this interplay is crucial for elucidating cellular responses to stress, as well as for its potential relevance in clinical applications and therapeutic strategies. Future research should focus on clarifying the molecular mechanisms that govern different forms of PCD and their interactions.

Iron homeostasis and ferroptosis in human diseases: mechanisms and therapeutic prospects

Iron, an essential mineral in the body, is involved in numerous physiological processes, making the maintenance of iron homeostasis crucial for overall health. Both iron overload and deficiency can cause various disorders and human diseases. Ferroptosis, a form of cell death dependent on iron, is characterized by the extensive peroxidation of lipids. Unlike other kinds of classical unprogrammed cell death, ferroptosis is primarily linked to disruptions in iron metabolism, lipid peroxidation, and antioxidant system imbalance. Ferroptosis is regulated through transcription, translation, and post-translational modifications, which affect cellular sensitivity to ferroptosis. Over the past decade or so, numerous diseases have been linked to ferroptosis as part of their etiology, including cancers, metabolic disorders, autoimmune diseases, central nervous system diseases, cardiovascular diseases, and musculoskeletal diseases. Ferroptosis-related proteins have become attractive targets for many major human diseases that are currently incurable, and some ferroptosis regulators have shown therapeutic effects in clinical trials although further validation of their clinical potential is needed. Therefore, in-depth analysis of ferroptosis and its potential molecular mechanisms in human diseases may offer additional strategies for clinical prevention and treatment. In this review, we discuss the physiological significance of iron homeostasis in the body, the potential contribution of ferroptosis to the etiology and development of human diseases, along with the evidence supporting targeting ferroptosis as a therapeutic approach. Importantly, we evaluate recent potential therapeutic targets and promising interventions, providing guidance for future targeted treatment therapies against human diseases.

PRODH Regulates Tamoxifen Resistance through Ferroptosis in Breast Cancer Cells

BACKGROUND

Estrogen receptor-positive breast cancer accounts for around 70% of all cases. Tamoxifen, an anti-estrogenic inhibitor, is the primary drug used for this type of breast cancer treatment. However, tamoxifen resistance is a major challenge in clinics. Metabolic reprogramming, an emerging hallmark of cancer, plays a key role in cancer initiation, progression, and therapy resistance. The metabolism of non-essential amino acids such as serine, proline, and glutamine is involved in tumor metabolism reprogramming. Although the association of glutamine metabolism with tamoxifen resistance has been well established, the role of proline metabolism and its critical enzyme PRODH is unknown.

OBJECTIVE

The aim of this study is to explore the role and mechanism of PRODH in tamoxifen resistance in breast cancer cells.

METHODS

PRODH and GPX4 expressions in tamoxifen-resistant cells were detected using real-time PCR and Western blot analysis. The breast cells' response to tamoxifen was measured using MTT assays. Trans-well assays were used to detect cell migration and invasion. A Xenograft tumor assay was used to detect the role of PRODH in tumor growth. Reactive oxygen species were measured using flow cytometry.

RESULTS

PRODH expression is reduced in tamoxifen-resistant cells, and its overexpression enhances tamoxifen response in vitro and in vivo. Conversely, PRODH knockdown confers tamoxifen resistance in tamoxifen-sensitive cells. Mechanistic studies show that ferroptosis is inhibited in tamoxifen-resistant cells and overexpression of PRODH restores the ferroptosis in tamoxifen-resistant cells. Moreover, Ferrostatin-1 (Fer-1), the ferroptosis inhibitor, reversed the effect of PRODH on tamoxifen resistance.

CONCLUSIONS

These findings suggest that PRODH regulates tamoxifen resistance by regulating ferroptosis in tamoxifen-resistant cells.

ROS-Responsive and Self-Catalytic Nanocarriers for a Combination of Chemotherapy and Reinforced Ferroptosis against Breast Cancer

Ferroptosis is an appealing cancer therapy strategy based on the H2O2-involved Fenton reaction to produce toxic •OH for lipid peroxidation. However, intracellular H2O2 is easily consumed and results in a deficient Fenton reaction. This obstacle can be overcome by traditional chemotherapeutic drugs for H2O2 supplements. Moreover, a recent work illustrated that dihydroartemisinin (DHA) could promote ferroptosis against tumoral cells, particularly in the presence of ferrous compounds. To achieve combined chemotherapy and ferroptosis, a nanocarrier (TKNPDHA-Fc) was constructed by using thioketal (TK)-bridged paclitaxel prodrug (PEG-TK-PTX) and ferrocene (Fc)-conjugated PEG-Fc, where DHA was encapsulated by a hydrophobic-hydrophobic interaction. Upon cellular uptake, TKNPDHA-Fc could facilitate PTX release through TK breakage under an excess H2O2 microenvironment. Owing to the loss of the hydrophobic PTX component, TKNPDHA-Fc underwent a rapid dissociation for improving DHA to act as a ferroptotic inducer along with Fe supplied from Fc. Moreover, both the chemotherapy-induced reactive oxygen species and the •OH produced from reinforced ferroptosis further stimulated the TK cleavage. The "self-catalytic" loop of TKNPDHA-Fc remarkably improved the antitumor performance in vivo via combined mechanisms, and its tumor inhibition rate reached 78.3%. This work highlights the contribution of ROS-responsive and self-catalytic nanoplatforms for enhancing the potential of combined chemotherapy and ferroptosis for cancer therapy in the future.

USP5 Stabilizes IKBKG Through Deubiquitination to Suppress Ferroptosis and Promote Growth in Non-small Cell Lung Cancer

Ferroptosis, a distinctive modality of cell mortality, has emerged as a critical regulator in non-small cell lung cancer (NSCLC). The deubiquitinating enzyme USP5 has established an oncogenic role in NSCLC. However, its biological relevance in NSCLC cell ferroptosis is currently unexplored. Expression analysis was performed by quantitative PCR (qPCR), immunohistochemistry (IHC) and immunoblotting. Animal xenograft studies were used to detect USP5's role in tumor growth. Cell proliferation, colony formation and apoptotic ratio were assessed by CCK-8, colony formation and flow cytometry assays, respectively. Cell ferroptosis was evaluated by gauging ROS, MDA, GSH, SOD, and Fe2+ contents. The USP5/IKBKG relationship and the ubiquitinated IKBKG were evaluated by Co-IP experiments. USP5 expression was elevated in human NSCLC. USP5 depletion suppressed NSCLC cell in vitro and in vivo growth and enhanced cell apoptosis. Moreover, USP5 depletion induced ferroptosis in NSCLC cell lines. Mechanistically, USP5 could enhance the stability of IKBKG protein through deubiquitination. Re-expression of IKBKG partially but significantly abolished USP5 depletion-mediated anti-growth and pro-ferroptosis effects in NSCLC cells. Our study demonstrates that USP5 suppresses ferroptosis and enhances growth in NSCLC cells by stabilizing IKBKG protein through deubiquitination. Targeting USP5 expression is an encouraging strategy to block NSCLC progression.

FTO/m6A mediates miR-138-5p maturation and regulates gefitinib resistance of lung adenocarcinoma cells by miR-138-5p/LCN2 axis

BACKGROUND

Lung cancer (LC) occupies an important position in the lethality of cancer patients. Acquired resistance to gefitinib in lung adenocarcinoma (LUAD) seriously affects the therapeutic efficacy of LC. Thus, it is of major scientific and clinical significance to probe the mechanism of gefitinib resistance in LUAD for ameliorating the prognosis of patients.

METHODS

The expression of miRNAs in gefitinib-resistant LUAD cells was validated using qRT-PCR. Cell viability was assessed through CCK-8, whereas cell death was examined through PI staining. Changes in the ferroptosis process were evaluated by detecting the intracellular Glutathione (GSH), Malondialdehyde (MDA), and Reactive Oxygen Species (ROS) levels. Downstream targets of miR-138-5p were verified via luciferase reporter and RNA pull-down assays. RIP and qRT-PCR were employed to evaluate pri-miR-138-5p binding to DiGeorge critical region 8 (DGCR8) and the pri-miR-138-5p m6A modification level. Additionally, the impact of fat mass and obesity-associated protein (FTO) on LUAD gefitinib sensitivity was assessed in vivo by constructing a xenograft model.

RESULTS

We observed that miR-138-5p was notably diminished in gefitinib-resistant cells. Overexpression of miR-138-5p suppressed viability while facilitated cell death and intracellular ferroptosis in gefitinib-resistant cells. Moreover, lipocalin 2 (LCN2) was the downstream target of miR-138-5p. The biological functions of miR-138-5p on gefitinib-resistant cells was reversed by introduction of LCN2. FTO suppressed the binding of DGCR8 to pri-miR-138-5p through m6A modification, thereby restraining the processing of miR-138-5p. Meanwhile, silencing of FTO enhanced the sensitivity of LUAD to gefitinib treatment.

CONCLUSION

FTO suppressed the processing of miR-138-5p and then modulated the proliferation, death, and ferroptosis of gefitinib-resistant cells through the miR-138-5p/LCN2 pathway, which may put forward novel insights for clinically ameliorating the therapeutic effect of gefitinib in LUAD.

Mechanisms of ferroptosis and targeted therapeutic approaches in urological malignancies

The prevalence of urological malignancies remains a significant global health concern, particularly given the challenging prognosis for patients in advanced disease stages. Consequently, there is a pressing need to explore the molecular mechanisms that regulate the development of urological malignancies to discover novel breakthroughs in diagnosis and treatment. Ferroptosis, characterized by iron-ion-dependent lipid peroxidation, is a form of programmed cell death (PCD) distinct from apoptosis, autophagy, and necrosis. Notably, lipid, iron, and glutathione metabolism intricately regulate intracellular ferroptosis, playing essential roles in the progression of various neoplasms and drug resistance. In recent years, ferroptosis has been found to be closely related to urological malignancies. This paper provides an overview of the involvement of ferroptosis in the pathogenesis and progression of urological malignancies, elucidates the molecular mechanisms governing its regulation, and synthesizes recent breakthroughs in diagnosing and treating these malignancies. We aim to provide a new direction for the clinical treatment of urological malignancies.