SLC7A11 regulated by NRF2 modulates esophageal squamous cell carcinoma radiosensitivity by inhibiting ferroptosis

Hernandezine acts as a CDK4 suppressor inhibiting tumor growth by the CDK4/PKM2/NRF2 axis in colon cancer

BACKGROUND

The cyclin-dependent kinase 4 (CDK4) interacts with its canonical and non-canonical substrates modulating the cell cycle in tumor cells. However, the potential substrates and the beyond-cell-cycle-regulated functions of CDK4 in colon cancer (CC) are still unknown. Hernandezine (HER) is previously verified to induce G0/G1 phase arrest and autophagic cell death in human cancer cells, which implies that HER might target G0/G1 phase-related proteins, including CDK4.

PURPOSE

The present study tried to investigate the glycolytic metabolism and oxidative stress functions of CDK4 in colon cancer. Furthermore, the inhibitory effects and potential binding sites of HER on CDK4, as well as its anti-tumor activity were investigated in CC cells.

METHODS

The mass spectrometry assay was performed to identify potential endogenous substrates of CDK4 and the correlation between glycolytic metabolic rate and CDK4 level in COAD patient tissues. Meanwhile, after inhibiting the activity or the expression of CDK4, the binding capacity of CDK4 to PKM2 and NRF2 and the latter two protein distributions in cytoplasm and nucleus were detected in CC cells. In vitro, the regulatory effects of the CDK4-PKM2-NRF2 axis on glycolysis and oxidative stress were performed by ECAR, OCR, and ROS assay. The inhibitory effect of HER on CDK4 activity was explored in CC cells and the potential binding sites were predicted and testified in vitro. Furthermore, tumor growth inhibition of HER by suppressing the CDK4-PKM2-NRF2 axis was also investigated in vitro and in vivo.

RESULTS

PKM2 and NRF2 were identified as endogenous substrates of CDK4 and, high-expressed CDK4 was associated with low-level glycolysis in COAD. In vitro, inactivated CDK4 facilitated CDK4-PKM2-NRF2 complex formation which resulted in 1) inhibited PKM2 activity and retarded the glycolytic rate; 2) cytoplasm-detained NRF2 failed to transcript anti-oxidative gene expressions and induced oxidant stress. Additionally, as a CDK4 inhibitor, HER developed triple anti-tumor effects including induced G0/G1 phase arrest, suppressed glycolysis, and disrupted the anti-oxidative capacity of CC cells.

CONCLUSION

The results first time revealed that CDK4 modulated glycolytic and anti-oxidative capacity of CC cells via bound to its endogenous substrates, PKM2 and NRF2. Additionally, 140Asp145Asn amino acid sites of CDK4 were potential targets of HER. HER exerts anti-tumor activity by inhibited the activity of CDK4, promoted the CDK4-PKM2-NRF2 complex formation in the CC cells.

Magnolol against enterovirus 71 by targeting Nrf2-SLC7A11-GSH pathway

Enterovirus 71 (EV71), a prominent pathogen associated with hand, foot, and mouth disease (HFMD), has been reported worldwide. To date, the advancement of effective drugs targeting EV71 remains in the preliminary experimental stage. In this study, magnolol demonstrated a significant dose-dependent inhibition of EV71 replication in vitro. It upregulated the overall expression level of nuclear factor erythroid 2 - related factor 2 (Nrf2) and facilitated its nucleus translocation, resulting in the increased expression of various ferroptosis inhibitory genes. This process led to a reduction in reactive oxygen species (ROS) accumulation induced by viral infection. Additionally, magnolol exhibited a broad-spectrum antiviral effect against enteroviruses. Notably, treatment with magnolol substantially enhanced the survival rate of EV71-infected mice, attenuated viral load in heart, liver, brain, and limb tissues, and mitigated tissue inflammation. Taken together, magnolol emerges as a promising candidate for the development of anti-EV71 drugs.

Clobetasol propionate, a Nrf-2 inhibitor, sensitizes human lung cancer cells to radiation-induced killing via mitochondrial ROS-dependent ferroptosis

Combining radiotherapy with Nrf-2 inhibitor holds promise as a potential therapeutic strategy for radioresistant lung cancer. Here, the radiosensitizing efficacy of a synthetic glucocorticoid clobetasol propionate (CP) in A549 human lung cancer cells was evaluated. CP exhibited potent radiosensitization in lung cancer cells via inhibition of Nrf-2 pathway, leading to elevation of oxidative stress. Transcriptomic studies revealed significant modulation of pathways related to ferroptosis, fatty acid and glutathione metabolism. Consistent with these findings, CP treatment followed by radiation exposure showed characteristic features of ferroptosis in terms of mitochondrial swelling, rupture and loss of cristae. Ferroptosis is a form of regulated cell death triggered by iron-dependent ROS accumulation and lipid peroxidation. In combination with radiation, CP showed enhanced iron release, mitochondrial ROS, and lipid peroxidation, indicating ferroptosis induction. Further, iron chelation, inhibition of lipid peroxidation or scavenging mitochondrial ROS prevented CP-mediated radiosensitization. Nrf-2 negatively regulates ferroptosis through upregulation of antioxidant defense and iron homeostasis. Interestingly, Nrf-2 overexpressing A549 cells were refractory to CP-mediated ferroptosis induction and radiosensitization. Thus, this study identified anti-psoriatic drug clobetasol propionate can be repurposed as a promising radiosensitizer for Keap-1 mutant lung cancers.

Protein modification and degradation in ferroptosis

Ferroptosis is a form of iron-related oxidative cell death governed by an integrated redox system, encompassing pro-oxidative proteins and antioxidative proteins. These proteins undergo precise control through diverse post-translational modifications, including ubiquitination, phosphorylation, acetylation, O-GlcNAcylation, SUMOylation, methylation, N-myristoylation, palmitoylation, and oxidative modification. These modifications play pivotal roles in regulating protein stability, activity, localization, and interactions, ultimately influencing both the buildup of iron and lipid peroxidation. In mammalian cells, regulators of ferroptosis typically undergo degradation via two principal pathways: the ubiquitin-proteasome system, which handles the majority of protein degradation, and autophagy, primarily targeting long-lived or aggregated proteins. This comprehensive review aims to summarize recent advances in the post-translational modification and degradation of proteins linked to ferroptosis. It also discusses strategies for modulating ferroptosis through protein modification and degradation systems, providing new insights into potential therapeutic applications for both cancer and non-neoplastic diseases.

Ferrostatin-1 inhibits fibroblast fibrosis in keloid by inhibiting ferroptosis

Background

Keloid is a chronic proliferative fibrotic disease caused by abnormal fibroblasts proliferation and excessive extracellular matrix (ECM) production. Numerous fibrotic disorders are significantly influenced by ferroptosis, and targeting ferroptosis can effectively mitigate fibrosis development. This study aimed to investigate the role and mechanism of ferroptosis in keloid development.

Methods

Keloid tissues from keloid patients and normal skin tissues from healthy controls were collected. Iron content, lipid peroxidation (LPO) level, and the mRNA and protein expression of ferroptosis-related genes including solute carrier family 7 member 11 (SLC7A11), glutathione peroxidase 4 (GPX4), transferrin receptor (TFRC), and nuclear factor erythroid 2-related factor 2 (Nrf2) were determined. Mitochondrial morphology was observed using transmission electron microscopy (TEM). Keloid fibroblasts (KFs) were isolated from keloid tissues, and treated with ferroptosis inhibitor ferrostatin-1 (fer-1) or ferroptosis activator erastin. Iron content, ferroptosis-related marker levels, LPO level, mitochondrial membrane potential, ATP content, and mitochondrial morphology in KFs were detected. Furthermore, the protein levels of α-smooth muscle actin (α-SMA), collagen I, and collagen III were measured to investigate whether ferroptosis affect fibrosis in KFs.

Results

We found that iron content and LPO level were substantially elevated in keloid tissues and KFs. SLC7A11, GPX4, and Nrf2 were downregulated and TFRC was upregulated in keloid tissues and KFs. Mitochondria in keloid tissues and KFs exhibited ferroptosis-related pathology. Fer-1 treatment reduced iron content, restrained ferroptosis and mitochondrial dysfunction in KFs, Moreover, ferrostatin-1 restrained the protein expression of α-SMA, collagen I, and collagen III in KFs. Whereas erastin treatment showed the opposite results.

Conclusion

Ferroptosis exists in keloid. Ferrostatin-1 restrained ECM deposition and fibrosis in keloid through inhibiting ferroptosis, and erastin induced ECM deposition and fibrosis through intensifying ferroptosis.

The significance of serum SLC7A11 levels in the occurrence of vascular calcification in maintenance peritoneal dialysis patients

AIM

This research aimed to explore the serum levels of solute carrier family 7 member 11 (SLC7A11) in patients with maintenance peritoneal dialysis (MPD) and its correlation with vascular calcification (VC) and clinical results.

METHODS

This present prospective observational cohort study enrolled 189 patients with MPD who were undergoing regular peritoneal dialysis for over 3 months in our hospital from February 2020 to July 2022. The abdominal aortic calcification score was used to assess the VC condition of MPD patients. The serum SLC7A11, interleukin (IL)-6, IL-1β and C-reactive protein levels were measured by enzyme-linked immunosorbent assay (ELISA). Demographic and clinical statistics were collected. All patients were followed up for 1 year and the overall survival time (OS) of all patients were recorded. All data used SPSS 18.0 for statistical analyses.

RESULTS

Patients with moderate/severe calcification in MPD had a longer duration of dialysis, higher serum levels of phosphate (P) and calcium (Ca) and lower serum levels of SLC7A11. Spearman's analysis revealed a negative correlation between serum SLC7A11 levels and the levels of P, Ca and IL-1β. Additionally, we observed an association between serum SLC7A11 levels and clinical prognosis as well as the extent of VC in MPD patients. Multivariate logistic regression analysis indicated that dialysis duration, SLC7A11, and P were risk factors for VC in MPD patients.

CONCLUSION

The serum SLC7A11 levels decreased remarkably in MPD patients with moderate/severe calcification. This study may provide new targets and comprehensive approach to cardiovascular protection in patients with chronic kidney disease.

Identification of a disulfidptosis-related prognostic signature for prediction of the effect of treatment in patients with endometrial carcinoma

Background

Disulfide, an essential compounds family, has diverse biological activity and can affect the dynamic balance between physiological and pathological states. A recently published study found that aberrant accumulation of disulfide had a lethal effect on cells. This mechanism of cell death, named disulfidptosis, differs from other known cell death mechanisms, including cuproptosis, apoptosis, necroptosis, and pyroptosis. The relationship between disulfidptosis and development of cancer, in particular endometrial carcinoma, remains unclear.

Methods

To address this knowledge gap, we performed a preliminary analysis of samples from The Cancer Genome Atlas database. The samples were divided equally into a training group and a test group. A total of 2308 differentially expressed genes were extracted, and 11 were used to construct a prognostic model.

Results

Based on the risk score calculated using the prognostic model, the samples were divided into a high-risk group and a low-risk group. Survival time, tumor mutation burden, and microsatellite instability scores differed significantly between the two groups. Furthermore, a between-group difference in treatment effect was predicted. Comparison with other models in the literature indicated that this prognostic model had better predictive anility.

Conclusion

The results of this study provide a general framework for understanding the relationship between disulfidptosis and endometrial cancer that could be used for clinical evaluation and selection of appropriate personalized treatment strategies.

Amino acid transporters within the solute carrier superfamily: Underappreciated proteins and novel opportunities for cancer therapy

BACKGROUND

Solute carrier (SLC) transporters, a diverse family of membrane proteins, are instrumental in orchestrating the intake and efflux of nutrients including amino acids, vitamins, ions, nutrients, etc, across cell membranes. This dynamic process is critical for sustaining the metabolic demands of cancer cells, promoting their survival, proliferation, and adaptation to the tumor microenvironment (TME). Amino acids are fundamental building blocks of cells and play essential roles in protein synthesis, nutrient sensing, and oncogenic signaling pathways. As key transporters of amino acids, SLCs have emerged as crucial players in maintaining cellular amino acid homeostasis, and their dysregulation is implicated in various cancer types. Thus, understanding the intricate connections between amino acids, SLCs, and cancer is pivotal for unraveling novel therapeutic targets and strategies.

SCOPE OF REVIEW

In this review, we delve into the significant impact of amino acid carriers of the SLCs family on the growth and progression of cancer and explore the current state of knowledge in this field, shedding light on the molecular mechanisms that underlie these relationships and highlighting potential avenues for future research and clinical interventions.

MAJOR CONCLUSIONS

Amino acids transportation by SLCs plays a critical role in tumor progression. However, some studies revealed the tumor suppressor function of SLCs. Although several studies evaluated the function of SLC7A11 and SLC1A5, the role of some SLC proteins in cancer is not studied well. To exert their functions, SLCs mediate metabolic rewiring, regulate the maintenance of redox balance, affect main oncogenic pathways, regulate amino acids bioavailability within the TME, and alter the sensitivity of cancer cells to therapeutics. However, different therapeutic methods that prevent the function of SLCs were able to inhibit tumor progression. This comprehensive review provides insights into a rapidly evolving area of cancer biology by focusing on amino acids and their transporters within the SLC superfamily.

The role of ferroptosis in radiotherapy and combination therapy for head and neck squamous cell carcinoma (Review)

Head and neck squamous cell carcinoma (HNSCC) is a highly aggressive, heterogeneous tumour usually caused by alcohol and tobacco consumption, making it one of the most common malignancies worldwide. Despite the fact that various therapeutic approaches such as surgery, radiation therapy (RT), chemotherapy (CT) and targeted therapy have been widely used for HNSCC in recent years, its recurrence rate and mortality rate remain high. RT is the standard treatment choice for HNSCC, which induces reactive oxygen species production and causes oxidative stress, ultimately leading to tumour cell death. CT is a widely recognized form of cancer treatment that treats a variety of cancers by eliminating cancer cells and preventing them from reproducing. Immune checkpoint inhibitor and epidermal growth factor receptor are important in the treatment of recurrent or metastatic HNSCC. Iron death, a type of cell death regulated by peroxidative damage to phospholipids containing polyunsaturated fatty acids in cell membranes, has been found to be a relevant death response triggered by tumour RT in recent years. In the present review, an overview of the current knowledge on RT and combination therapy and iron death in HNSCC was provided, the mechanisms by which RT induces iron death in tumour cells were summarized, and therapeutic strategies to target iron death in HNSCC were explored. The current review provided important information for future studies of iron death in the treatment of HNSCC.

Competing endogenous RNA networks and ferroptosis in cancer: novel therapeutic targets

As a newly identified regulated cell death, ferroptosis is a metabolically driven process that relies on iron and is associated with polyunsaturated fatty acyl peroxidation, elevated levels of reactive oxygen species (ROS), and mitochondrial damage. This distinct regulated cell death is dysregulated in various cancers; activating ferroptosis in malignant cells increases cancer immunotherapy and chemoradiotherapy responses across different malignancies. Over the last decade, accumulating research has provided evidence of cross-talk between non-coding RNAs (ncRNAs) and competing endogenous RNA (ceRNA) networks and highlighted their significance in developing and progressing malignancies. Aside from pharmaceutical agents to regulate ferroptosis, recent studies have shed light on the potential of restoring dysregulated ferroptosis-related ceRNA networks in cancer treatment. The present study provides a comprehensive and up-to-date review of the ferroptosis significance, ferroptosis pathways, the role of ferroptosis in cancer immunotherapy and chemoradiotherapy, ceRNA biogenesis, and ferroptosis-regulating ceRNA networks in different cancers. The provided insights can offer the authorship with state-of-the-art findings and future perspectives regarding the ferroptosis and ferroptosis-related ceRNA networks and their implication in the treatment and determining the prognosis of affected patients.

Blocking SLC7A11 attenuates the proliferation of esophageal squamous cell carcinoma cells

The role of ferroptosis-associated gene SLC7A11 in esophageal cancer progression is largely unknown, therefore, the effects of blocking SLC7A11 on esophageal squamous cell carcinoma (ESCC) cells are evaluated. Results showed that SLC7A11 was overexpressed in ESCC tissues both in mRNA and protein levels. Blocking SLC7A11 using Erastin suppressed the proliferation and colony formation of ESCC cells, decreased cellular ATP levels, and improved ROS production. Sixty-three SLC7A11-binding proteins were identified using the IP-MS method, and these proteins were enriched in four signaling pathways, including spliceosome, ribosome, huntington disease, and diabetic cardiomyopathy. The deubiquitinase inhibitors PR-619, GRL0617, and P 22077 could reduce at least 40% protein expression level of SLC7A11 in ESCC cells, and PR-619 and GRL0617 exhibited suppressive effects on the cell viability and colony formation ability of KYSE30 cells, respectively. Erastin downregulated GPX4 and DHODH and also reduced the levels of β-catenin, p-STAT3, and IL-6 in ESCC cells. In conclusion, SLC7A11 was overexpressed in ESCC, and blocking SLC7A11 using Erastin mitigated malignant phenotypes of ESCC cells and downregulated key ferroptosis-associated molecules GPX4 and DHODH. The therapeutic potential of targeting SLC7A11 should be further evaluated in the future.

Ononin triggers ferroptosis-mediated disruption in the triple negative breast cancer both in vitro and in vivo

Triple-negative breast cancer (TNBC) is a subtype of breast cancer that is difficult to treat due to a lack of targeted therapies. In this study, we aimed to investigate whether a natural flavonoid compound called ononin could be effective in treating TNBC by triggering ferroptosis in MDA-MB-231 and 4 T1 cell lines, and MDA-MB-231-xenograft nude mice model. Ononin inhibited TNBC through ferroptosis, which was determined by MTT assay, flow cytometry, RT-PCR, immunofluorescence, transmission electron microscopy, histological analysis, western blot and bioluminescence assay. Our results showed that treatment with ononin led to increased levels of malondialdehyde and reactive oxygen species and decreased activity of superoxide dismutase, which are indicatives of ferroptosis. We also found that ononin downregulated two key markers of ferroptosis, SLC7A11 and Nrf2, at both the transcriptional and translational level. Additionally, the administration of ononin resulted in a notable decrease in tumor size and weight in the mouse model. Furthermore, it was observed to enhance the rate of apoptosis in TNBC cells. Importantly, ononin did not induce any histological changes in the kidney, liver, and heart. Taken together, our findings suggest that ononin could be a promising therapeutic strategy for TNBC, and that it works by disrupting the Nrf2/SLC7A11 axis through ferroptosis. These results are encouraging and may lead to the development of new treatments for this challenging cancer subtype.

Disulfidptosis, A Novel Cell Death Pathway: Molecular Landscape and Therapeutic Implications

Programmed cell death is pivotal for several physiological processes, including immune defense. Further, it has been implicated in the pathogenesis of developmental disorders and the onset of numerous diseases. Multiple modes of programmed cell death, including apoptosis, pyroptosis, necroptosis, and ferroptosis, have been identified, each with their own unique characteristics and biological implications. In February 2023, Liu Xiaoguang and his team discovered "disulfidptosis," a novel pathway of programmed cell death. Their findings demonstrated that disulfidptosis is triggered in glucose-starved cells exhibiting high expression of a protein called SLC7A11. Furthermore, disulfidptosis is marked by a drastic imbalance in the NADPH/NADP+ ratio and the abnormal accumulation of disulfides like cystine. These changes ultimately lead to the destabilization of the F-actin network, causing cell death. Given that high SLC7A11 expression is a key feature of certain cancers, these findings indicate that disulfidptosis could serve as the basis of innovative anti-cancer therapies. Hence, this review delves into the discovery of disulfidptosis, its underlying molecular mechanisms and metabolic regulation, and its prospective applications in disease treatment.

Nuclear factor erythroid 2-related factor 2 promotes radioresistance by regulating glutamate-cysteine ligase modifier subunit and its unique immunoinvasive pattern

The enzyme glutamate-cysteine ligase modifier subunit (GCLM) serves as the initial rate-limiting factor in glutathione (GSH) synthesis. GSH is the preferred substrate for glutathione peroxidase 4 (GPX4), directly impacting its activity and stability. This study aims to elucidate the expression of GCLM and its correlation with the nuclear factor erythroid 2-related factor 2 (NFE2L2), commonly referred to as NRF2, in esophageal squamous cell carcinoma (ESCC) and further investigate the potential signaling axis of radiotherapy resistance caused by NRF2-mediated regulation of ferroptosis in ESCC. The expression of NRF2, GCLM, and GPX4 in ESCC was analyzed by bioinformatics, and their relationship with ferroptosis was verified through cell function experiments. Their role in radioresistance was then investigated through multiple validation steps. Bioinformatics analysis was employed to determine the immune infiltration pattern of NRF2 in ESCC. Furthermore, the effect of NRF2-mediated massive macrophage M2 infiltration on radiotherapy and ferroptosis was validated through in vivo experiments. In vitro assays demonstrated that overactivated NRF2 promotes radioresistance by directly binding to the promoter region of GCLM. The Tumor Immune Estimation Resource (TIMER) and quanTIseq analyses revealed NRF2 enrichment in M2 macrophages with a positive correlation. Co-culturing KYSE450 cells with M2 macrophages demonstrated that a significant infiltration of macrophages M2 can render ESCC cells resistant to radiotherapy but restore their sensitivity to ferroptosis in the process. Our study elucidates a link between the NRF2-GCLM-GSH-GPX4 signaling axis in ESCC, highlighting its potential as a therapeutic target for antagonistic biomarkers of resistance in the future. Additionally, it provides a novel treatment avenue for ESCC metastasis and radioresistance.

Mechanism of metal ion-induced cell death in gastrointestinal cancer

Gastrointestinal (GI) cancer is one of the most severe types of cancer, with a significant impact on human health worldwide. Due to the urgent demand for more effective therapeutic strategies against GI cancers, novel research on metal ions for treating GI cancers has attracted increasing attention. Currently, with accumulating research on the relationship between metal ions and cancer therapy, several metal ions have been discovered to induce cell death. In particular, the three novel modes of cell death, including ferroptosis, cuproptosis, and calcicoptosis, have become focal points of research in the field of cancer. Meanwhile, other metal ions have also been found to trigger cell death through various mechanisms. Accordingly, this review focuses on the mechanisms of metal ion-induced cell death in GI cancers, hoping to provide theoretical support for further GI cancer therapies.

AhR signaling modulates Ferroptosis by regulating SLC7A11 expression

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that is pivotal in development, metabolic homeostasis, and immune responses. While recent research has highlighted AhR's significant role in modulating oxidative stress responses, its mechanistic relationship with ferroptosis-an iron-dependent, non-apoptotic cell death-remains to be fully elucidated. In our study, we discovered that AhR plays a crucial role in ferroptosis, in part by transcriptionally regulating the expression of the solute carrier family 7 member 11 (SLC7A11). Our findings indicate that both pharmacological inactivation and genetic ablation of AhR markedly enhance erastin-induced ferroptosis. This enhancement is achieved by suppressing SLC7A11, leading to increased lipid peroxidation. We also obtained evidence of post-translational modifications of SLC7A11 during ferroptosis. Additionally, we observed that indole 3-pyruvate (I3P), an endogenous ligand of AhR, protects cells from ferroptosis through an AhR-dependent mechanism. Based on these insights, we propose that AhR transcriptionally regulates the expression of SLC family genes, which in turn play a pivotal role in mediating ferroptosis. This underscores AhR's essential role in suppressing lipid oxidation and ensuring cell survival under oxidative stress.

The Experimental and In Silico-Based Evaluation of NRF2 Modulators, Sulforaphane and Brusatol, on the Transcriptome of Immortalized Bovine Mammary Alveolar Cells

Changes during the production cycle of dairy cattle can leave these animals susceptible to oxidative stress and reduced antioxidant health. In particular, the periparturient period, when dairy cows must rapidly adapt to the sudden metabolic demands of lactation, is a period when the production of damaging free radicals can overwhelm the natural antioxidant systems, potentially leading to tissue damage and reduced milk production. Central to the protection against free radical damage and antioxidant defense is the transcription factor NRF2, which activates an array of genes associated with antioxidant functions and cell survival. The objective of this study was to evaluate the effect that two natural NRF2 modulators, the NRF2 agonist sulforaphane (SFN) and the antagonist brusatol (BRU), have on the transcriptome of immortalized bovine mammary alveolar cells (MACT) using both the RT-qPCR of putative NRF2 target genes, as well as RNA sequencing approaches. The treatment of cells with SFN resulted in the activation of many putative NRF2 target genes and the upregulation of genes associated with pathways involved in cell survival, metabolism, and antioxidant function while suppressing the expression of genes related to cellular senescence and DNA repair. In contrast, the treatment of cells with BRU resulted in the upregulation of genes associated with inflammation, cellular stress, and apoptosis while suppressing the transcription of genes involved in various metabolic processes. The analysis also revealed several novel putative NRF2 target genes in bovine. In conclusion, these data indicate that the treatment of cells with SFN and BRU may be effective at modulating the NRF2 transcriptional network, but additional effects associated with cellular stress and metabolism may complicate the effectiveness of these compounds to improve antioxidant health in dairy cattle via nutrigenomic approaches.

Endometrial stem cells alleviate cisplatin-induced ferroptosis of granulosa cells by regulating Nrf2 expression

BACKGROUND

Premature ovarian failure (POF) caused by cisplatin is a severe and intractable sequela for young women with cancer who received chemotherapy. Cisplatin causes the dysfunction of granulosa cells and mainly leads to but is not limited to its apoptosis and autophagy. Ferroptosis has been also reported to participate, while little is known about it. Our previous experiment has demonstrated that endometrial stem cells (EnSCs) can repair cisplatin-injured granulosa cells. However, it is still unclear whether EnSCs can play a repair role by acting on ferroptosis.

METHODS

Western blotting and quantitative reverse-transcription polymerase chain reaction (qRT-PCR) were applied to detect the expression levels of ferroptosis-related genes. CCK-8 and 5-Ethynyl-2'-deoxyuridine (EdU) assays were used to evaluate cell viability. Transmission electron microscopy (TEM) was performed to detect ferroptosis in morphology. And the extent of ferroptosis was assessed by ROS, GPx, GSSG and MDA indicators. In vivo, ovarian morphology was presented by HE staining and the protein expression in ovarian tissue was detected by immunohistochemistry.

RESULTS

Our results showed that ferroptosis could occur in cisplatin-injured granulosa cells. Ferroptosis inhibitor ferrostatin-1 (Fer-1) and EnSCs partly restored cell viability and mitigated the damage of cisplatin to granulosa cells by inhibiting ferroptosis. Moreover, the repair potential of EnSCs can be markedly blocked by ML385.

CONCLUSION

Our study demonstrated that cisplatin could induce ferroptosis in granulosa cells, while EnSCs could inhibit ferroptosis and thus exert repair effects on the cisplatin-induced injury model both in vivo and in vitro. Meanwhile, Nrf2 was validated to participate in this regulatory process and played an essential role.

Danggui Buxue Tang improves therapeutic efficacy of doxorubicin in triple negative breast cancer via ferroptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Danggui Buxue Tang (DBT) has been used for over 800 years to enhance Qi and nourish Blood, and it is particularly beneficial for cancer patients. Recent research has shown that combining DBT with chemotherapy agents leads to superior anti-cancer effects, thereby enhancing therapeutic efficacy.

AIM OF THE STUDY

The aim of this study was to evaluate the effectiveness of a combination therapy involving doxorubicin (DOX) and Danggui Buxue Tang (DBT) in the treatment of triple-negative breast cancer (TNBC) and to elucidate the underlying mechanisms of action.

MATERIALS AND METHODS

In vitro experiments were performed using MDA-MB-231 and 4T1 cells, while in vivo experiments were carried out using MDA-MB-231 xenograft mice. The therapeutic effects of the combination therapy were evaluated using various techniques, including MTT assay, colony formation assay, flow cytometry, transwell assay, immunofluorescence, transmission electron microscopy (TEM), histological analysis, western blotting, and bioluminescence assay.

RESULTS

DBT was found to enhance DOX's anti-TNBC activity in vitro by promoting ferroptosis, as evidenced by the observed mitochondrial morphological changes using TEM. The combination therapy was also found to reduce the expression of Nrf2, HO-1, and GPX4, which are all targets for ferroptosis induction, while simultaneously increasing ROS production. Additionally, the combination therapy reduced nuclear accumulation and constitutive activation of Nrf2, which is a significant cause of chemotherapy resistance and promotes cancer growth. In vivo experiments using an MDA-MB-231 xenograft animal model revealed that the combination therapy significantly reduced tumor cell proliferation and accelerated TNBC deaths by modulating the Nrf2/HO-1/GPX4 axis, with no evidence of tissue abnormalities. Moreover, the combination therapy exhibited a liver protective effect, and administration of Fer-1 was able to reduce the ROS formation produced by the DBT + DOX combination therapy.

CONCLUSION

This study provides evidence that the combination therapy of DOX and DBT has the potential to treat TNBC by promoting ferroptosis through the Nrf2/HO-1/GPX4 axis.

Emerging trends of phytochemicals as ferroptosis modulators in cancer therapy

Ferroptosis, a novel form of regulated cell death characterized by dependence on iron and lipid peroxidation, has been implicated in a wide range of clinical conditions including neurological diseases, cardiovascular disorders, acute kidney failure, and various types of cancer. Therefore, it is critical to suppress cancer progression and proliferation. Ferroptosis can be triggered in cancer cells and some normal cells by synthetic substances, such as erastin, Ras-selective lethal small molecule-3, or clinical pharmaceuticals. Natural bioactive compounds are traditional drug discovery tools, and some have been therapeutically used as dietary additives or pharmaceutical agents against various malignancies. The fact that natural products have multiple targets and minimal side effects has led to notable advances in anticancer research. Research has indicated that ferroptosis can also be induced by natural compounds during cancer treatment. In this review, we focused on the most recent developments in emerging molecular processes and the significance of ferroptosis in cancer. To provide new perspectives on the future development of ferroptosis-related anticancer medications, we also provide a summary of the implications of natural phytochemicals in triggering ferroptosis through ROS production and ferritinophagy induction in a variety of malignancies.

Ferroptosis contributing to cardiomyocyte injury induced by silica nanoparticles via miR-125b-2-3p/HO-1 signaling

BACKGROUND

Amorphous silica nanoparticles (SiNPs) have been gradually proven to threaten cardiac health, but pathogenesis has not been fully elucidated. Ferroptosis is a newly defined form of programmed cell death that is implicated in myocardial diseases. Nevertheless, its role in the adverse cardiac effects of SiNPs has not been described.

RESULTS

We first reported the induction of cardiomyocyte ferroptosis by SiNPs in both in vivo and in vitro. The sub-chronic exposure to SiNPs through intratracheal instillation aroused myocardial injury, characterized by significant inflammatory infiltration and collagen hyperplasia, accompanied by elevated CK-MB and cTnT activities in serum. Meanwhile, the activation of myocardial ferroptosis by SiNPs was certified by the extensive iron overload, declined FTH1 and FTL, and lipid peroxidation. The correlation analysis among detected indexes hinted ferroptosis was responsible for the SiNPs-aroused myocardial injury. Further, in vitro tests, SiNPs triggered iron overload and lipid peroxidation in cardiomyocytes. Concomitantly, altered expressions of TfR, DMT1, FTH1, and FTL indicated dysregulated iron metabolism of cardiomyocytes upon SiNP stimuli. Also, shrinking mitochondria with ridge fracture and ruptured outer membrane were noticed. To note, the ferroptosis inhibitor Ferrostatin-1 could effectively alleviate SiNPs-induced iron overload, lipid peroxidation, and myocardial cytotoxicity. More importantly, the mechanistic investigations revealed miR-125b-2-3p-targeted HO-1 as a key player in the induction of ferroptosis by SiNPs, probably through regulating the intracellular iron metabolism to mediate iron overload and ensuing lipid peroxidation.

CONCLUSIONS

Our findings firstly underscored the fact that ferroptosis mediated by miR-125b-2-3p/HO-1 signaling was a contributor to SiNPs-induced myocardial injury, which could be of importance to elucidate the toxicity and provide new insights into the future safety applications of SiNPs-related nano products.

Identification and prognostic analysis of ferroptosis‑related gene HSPA5 to predict the progression of lung squamous cell carcinoma

Ferroptosis, an iron-dependent form of regulated cell death driven by excessive lipid peroxidation, is implicated in the development and therapeutic responses of cancer. However, the role of ferroptosis-related gene profiles in lung squamous cell carcinoma (LSCC) remains largely unknown. The present study aimed to identify the prognostic roles of ferroptosis-related genes in LSCC. Sequencing data from the Cancer Genome Atlas were analyzed and ferroptosis-related gene expression between tumor and para-tumor tissue was identified. The prognostic role of these genes was also assessed using Kaplan-Meier analyses and univariate and multivariate Cox proportional hazards regression model analyses. Immunological correlation, tumor stemness, drug sensitivity and the transcriptional differences of heat shock protein (HSP)A5 in LSCC were also analyzed. Thereafter, the expression of HSPA5 in 100 patients with metastatic LSCC was evaluated using immunohistochemistry (IHC) and the clinical significance of these markers with different risk factors was assessed. Of the 22 ferroptosis-related genes, the expression of HSPA5, HSPB1, glutathione peroxidase 4, Fanconi anemia complementation group D2, CDGSH iron sulfur domain 1, farnesyl-diphosphate farnesyltransferase 1, nuclear factor erythroid 2 like 2, solute carrier (SLC)1A5, ribosomal protein L8, nuclear receptor coactivator 4, transferrin receptor and SLC7A11 was significantly increased in LSCC compared with adjacent tissues. However, only high expression of HSPA5 was able to predict progression-free survival (PFS) and disease-free survival in LSCC. Although HSPA5 was also significantly elevated in patients with lung adenocarcinoma, HSPA5 expression did not predict the prognosis of patients with lung adenocarcinoma. Of note, a higher expression of HSPA5 was related to higher responses to chemotherapy but not to immunotherapy. In addition, HSPA5 expression was positively correlated with 'ferroptosis', 'cellular responses to hypoxia', 'tumor proliferation signature', 'G2M checkpoint', 'MYC targets' and 'TGFB'. IHC analysis also demonstrated that a high expression of HSPA5 in patients with metastatic LSCC in the study cohort was associated with shorter PFS and overall survival. In conclusion, the present study demonstrated that the expression of the ferroptosis-related gene HSPA5 may be a negative prognostic marker for LSCC.

Structural characterization and ferroptosis-related immunomodulatory of a novel exopolysaccharide isolated from marine fungus Aspergillus medius

Marine fungal exopolysaccharides play a crucial role in immunoregulation. In this investigation, a novel polysaccharide was extracted from the culture medium of the marine fungus Aspergillus medius SCAU-236. Compositional analysis revealed a structure composed of glucose units with (1,4)-α-D-Glcp, (1,3,4)-β-D-Glcp, and (1,4,6)-α-D-Glcp, along with side chains of 1-α-D-Glcp linked to carbon 6 of (1,4,6)-α-D-Glcp and carbon 3 of (1,3,4)-β-D-Glcp. Functional evaluations on RAW264.7 macrophage cells demonstrated Aspergillus medius polysaccharide (ASMP)'s effects on cell proliferation, nitric oxide levels, and the secretion of TNF-α, IL-6, and IL-1β cytokines. Additionally, metabolomics indicated ASMP's potential to modulate macrophage immune function by impacting key regulatory molecules, including COX-2, iNOS, Nrf2, SLC7A11, GPX4, and ACSL4. The Nrf2/SLC7A11/GPX4 axis and ACSL4 were suggested to be involved in ASMP-induced ferroptosis, leading to increased reactive oxygen species (ROS) levels and lipid peroxidation. These findings propose a unique mechanism by which ASMP exerts immunomodulatory effects through ferroptosis induction, contributing to the understanding of marine-derived compounds in immunomodulation research.

Single-cell transcriptomic sequencing data reveal aberrant DNA methylation in SMAD3 promoter region in tumor-associated fibroblasts affecting molecular mechanism of radiosensitivity in non-small cell lung cancer

OBJECTIVE

Non-small cell lung cancer (NSCLC) often exhibits resistance to radiotherapy, posing significant treatment challenges. This study investigates the role of SMAD3 in NSCLC, focusing on its potential in influencing radiosensitivity via the ITGA6/PI3K/Akt pathway.

METHODS

The study utilized gene expression data from the GEO database to identify differentially expressed genes related to radiotherapy resistance in NSCLC. Using the GSE37745 dataset, prognostic genes were identified through Cox regression and survival analysis. Functional roles of target genes were explored using Gene Set Enrichment Analysis (GSEA) and co-expression analyses. Gene promoter methylation levels were assessed using databases like UALCAN, DNMIVD, and UCSC Xena, while the TISCH database provided insights into the correlation between target genes and CAFs. Experiments included RT-qPCR, Western blot, and immunohistochemistry on NSCLC patient samples, in vitro studies on isolated CAFs cells, and in vivo nude mouse tumor models.

RESULTS

Fifteen key genes associated with radiotherapy resistance in NSCLC cells were identified. SMAD3 was recognized as an independent prognostic factor for NSCLC, linked to poor patient outcomes. High expression of SMAD3 was correlated with low DNA methylation in its promoter region and was enriched in CAFs. In vitro and in vivo experiments confirmed that SMAD3 promotes radiotherapy resistance by activating the ITGA6/PI3K/Akt signaling pathway.

CONCLUSION

High expression of SMAD3 in NSCLC tissues, cells, and CAFs is closely associated with poor prognosis and increased radiotherapy resistance. SMAD3 is likely to enhance radiotherapy resistance in NSCLC cells by activating the ITGA6/PI3K/Akt signaling pathway.

Ferroptosis in lung cancer: dual role, multi-level regulation, and new therapeutic strategies

Lung cancer is a highly prevalent malignant tumor worldwide, with high incidence and death rates. Recently, there has been increasing recognition of the role of ferroptosis, a unique cell death mechanism, in lung cancer. This review aims to summarize the current research progress on the relationship between ferroptosis and lung cancer. It also provides a comprehensive analysis of the regulatory processes of ferroptosis in various stages, including epigenetics, transcription, post-transcription, translation, and post-translation. Additionally, the review explores the dual nature of ferroptosis in lung cancer progression, which presents interesting therapeutic possibilities. On one hand, ferroptosis can promote the escape of immune surveillance and reduce the efficacy of treatment in the early stages of tumors. On the other hand, it can counter drug resistance, enhance radiosensitivity, and promote immunotherapy. The article also discusses various combination treatment strategies based on the mechanism of ferroptosis. Overall, this review offers a holistic perspective on the role of ferroptosis in the onset, progression, and treatment of lung cancer. It aims to contribute to future research and clinical interventions in this field.

Protective Effect of Compound Tongluo Decoction on Brain Vascular Endothelial Cells after Ischemia-Reperfusion by Inhibition of Ferroptosis Through Regulating Nrf2/ARE/SLC7A11 Signaling Pathway

Cerebral infarction is one of the most common diseases for aged people. Compound Tongluo Decoction (CTLD), a classic traditional Chinese Medicine prescription, has been widely used in the treatment of ischemic cerebral infarction. Transient middle cerebral artery occlusion (tMCAO) rat model is established for the animal experiment and oxygen-glucose deprivation and reperfusion (OGD/R) human umbilical vein endothelial cells (HUVECs) model are established for the cell experiment. This also use Nrf2-/- rats to detect the role of nuclear factor erythroid 2-related factor 2 (Nrf2). Longa score, Evans blue staining, brain water content measurement, and histological observation are done. The levels of reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), and other ferroptosis-related components are detected respectively. In the vivo experiment, CTLD relieved ischemia-reperfusion (IR) injury symptoms and attenuated IR injury in brain tissues of tMCAO rats by relieving peroxidation injury in brain tissues and inhibiting ferroptosis in tMCAO rats. Moreover, CTLD reversed OGD/R-induced oxidative damage of endothelial cells via suppressing ferroptosis. After knocking out the Nrf2 gene, the protective effect of CTLD is sharply reduced. This study put forward that CTLD can inhibit ferroptosis in I/R-injured vascular endothelium by regulating Nrf2/ARE/SLC7A11 signaling to improve the relative symptoms of rats after cerebral I/R injury, thus providing a viable treatment option for cerebrovascular disease.

Targeting SIRT3 sensitizes glioblastoma to ferroptosis by promoting mitophagy and inhibiting SLC7A11

Glioblastoma (GBM) cells require large amounts of iron for tumor growth and progression, which makes these cells vulnerable to destruction via ferroptosis induction. Mitochondria are critical for iron metabolism and ferroptosis. Sirtuin-3 (SIRT3) is a deacetylase found in mitochondria that regulates mitochondrial quality and function. This study aimed to characterize SIRT3 expression and activity in GBM and investigate the potential therapeutic effects of targeting SIRT3 while also inducing ferroptosis in these cells. We first found that SIRT3 expression was higher in GBM tissues than in normal brain tissues and that SIRT3 protein expression was upregulated during RAS-selective lethal 3 (RSL3)-induced GBM cell ferroptosis. We then observed that inhibition of SIRT3 expression and activity in GBM cells sensitized GBM cells to RSL3-induced ferroptosis both in vitro and in vivo. Mechanistically, SIRT3 inhibition led to ferrous iron and ROS accumulation in the mitochondria, which triggered mitophagy. RNA-Sequencing analysis revealed that upon SIRT3 knockdown in GBM cells, the mitophagy pathway was upregulated and SLC7A11, a critical antagonist of ferroptosis via cellular import of cystine for glutathione (GSH) synthesis, was downregulated. Forced expression of SLC7A11 in GBM cells with SIRT3 knockdown restored cellular cystine uptake and consequently the cellular GSH level, thereby partially rescuing cell viability upon RSL3 treatment. Furthermore, in GBM cells, SIRT3 regulated SLC7A11 transcription through ATF4. Overall, our study results elucidated novel mechanisms underlying the ability of SIRT3 to protect GBM from ferroptosis and provided insight into a potential combinatorial approach of targeting SIRT3 and inducing ferroptosis for GBM treatment.

Inhibition of NRF2 enhances the acute myeloid leukemia cell death induced by venetoclax via the ferroptosis pathway

Venetoclax, an inhibitor that selectively targets B cell lymphoma-2 (BCL-2) that has been approved for treating adult acute myeloid leukemia (AML) in combination with hypomethylating agents. However, its short duration of response and emergence of resistance are significant issues. In this study, we found that the sensitivity of AML cells to venetoclax was considerably enhanced by ML385, an inhibitor of the ferroptosis factor nuclear transcription factor erythroid 2-related factor 2 (NRF2). Using AML samples, we verified that NRF2 and its target gene ferritin heavy chain 1 (FTH1) were highly expressed in patients with AML and correlated with poor prognosis. Downregulation of NRF2 could inhibit FTH1 expression and significantly enhance the venetoclax-induced labile iron pool and lipid peroxidation. By contrast, NRF2 overexpression or administration of the reactive oxygen species inhibitor N-acetylcysteine and vitamin E could effectively suppress the anti-AML effects of ML385+venetoclax. Furthermore, the ferroptosis inducer erastin increased the anti-AML effects of venetoclax. Our study demonstrated that NRF2 inhibition could enhance the AML cell death induced by venetoclax via the ferroptosis pathway. Thus, the combination of ML385 with venetoclax may offer a favorable strategy for AML treatment.

Suppression of the SLC7A11/glutathione axis causes ferroptosis and apoptosis and alters the mitogen-activated protein kinase pathway in nasopharyngeal carcinoma

SLC7A11 is a unit of the glutamate cystine antiporter Xc- system. It functions to import cystine for glutathione biosynthesis and maintains the redox balance in cells. Sorafenib inhibits the transporter activity of SLC7A11. The use of sorafenib has been approved in the treatment of multiple cancers. However, at present, our understanding of the mechanism of SLC7A11 and sorafenib in nasopharyngeal carcinoma (NPC) remains limited. We found that the expression of SLC7A11 was upregulated in NPC. A high SLC7A11 expression was associated with poor prognosis, metastasis, and an advanced T stage, which can be used as an independent prognostic indicator of NPC. In vitro, we observed that NPC cells relied on cystine for survival. Targeting SLC7A11 resulted in glutathione biosynthesis limitation, intracellular reactive oxygen species accumulation, lipid peroxides, ferroptosis, and apoptosis. Meanwhile, it altered mitogen activated protein kinase pathway, including p38 activation but ERK inhibition in NPC. This limited the proliferation of NPC cells. Sorafenib inhibited the proliferation and induced the death of NPC cells in vivo. In conclusion, SLC7A11 plays an important role in the occurrence and progression of NPC and may be a novel target for NPC treatment.

Metabolic heterogeneity in cancer

Cancer cells rewire their metabolism to survive during cancer progression. In this context, tumour metabolic heterogeneity arises and develops in response to diverse environmental factors. This metabolic heterogeneity contributes to cancer aggressiveness and impacts therapeutic opportunities. In recent years, technical advances allowed direct characterisation of metabolic heterogeneity in tumours. In addition to the metabolic heterogeneity observed in primary tumours, metabolic heterogeneity temporally evolves along with tumour progression. In this Review, we summarize the mechanisms of environment-induced metabolic heterogeneity. In addition, we discuss how cancer metabolism and the key metabolites and enzymes temporally and functionally evolve during the metastatic cascade and treatment.

CircTMEM87A promotes the tumorigenesis of gastric cancer by regulating the miR-1276/SLC7A11 axis

BACKGROUND

Gastric cancer (GC) is a common malignancy with high incidence and mortality, and its pathogenesis involves the regulation of circular RNAs (circRNAs). However, the molecular mechanism of circTMEM87A in GC malignant progression is uncertain.

METHODS

Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to detect the expressions of circTMEM87A, miR-1276, and solute carrier family 7 membrane 11 (SLC7A11). Western blot was applied to detect protein expression levels of EMT-related proteins (vimentin and E-cadherin) and SLC7A11. Cell counting kit-8 assay (CCK8) and thymidine analog 5-ethynyl-2'-deoxyuridine (EdU) were performed to assess cell proliferation. Apoptosis was investigated using flow cytometry. Transwell assay and wound healing assay were carried out to examine the migration of MKN-7 and AGS cells. The Cellular ROS Assay Kit, Iron Assay Kit, and GSH/GSSG Ratio Detection Assay Kit were utilized to monitor lipid ROS level, iron level, and GSH/GSSG ratio, respectively. The interaction between miR-1276 and circTMEM87A or SLC7A11 was investigated using dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. A xenograft mouse model was constructed to explore the function of circTMEM87A in tumor formation in vivo.

RESULTS

CircTMEM87A and SLC7A11 were upregulated, while miR-1276 was downregulated in GC tissues and cells. Knockdown of circTMEM87A suppressed the proliferation and migration and promoted apoptosis and ferroptosis of GC cells. CircTMEM87A served as a sponge for miR-1276, and miR-1276 inhibitor relieved the circTMEM87A knockdown-induced effects on GC cell phenotypes. Similarly, SLC7A11, a downstream gene of miR-1276, rescued miR-1276 overexpression-induced effects on GC cell function. Furthermore, circTMEM87A knockdown inhibited GC cell tumor phenotypes in vivo.

CONCLUSION

CircTMEM87A promoted the proliferation and migration and inhibited apoptosis and ferroptosis of GC cells by increasing SLC7A11 expression through binding to miR-1276.

YY1 modulates the radiosensitivity of esophageal squamous cell carcinoma through KIF3B-mediated Hippo signaling pathway

Radiotherapy is an important strategy in the comprehensive treatment of esophageal squamous cell carcinoma (ESCC). However, effectiveness of radiotherapy is still restricted by radioresistance. Herein, we aimed to understand the mechanisms underlying ESCC radioresistance, for which we looked into the potential role of YY1. YY1 was upregulated in radioresistant tissues and correlated with poor prognosis of patients with ESCC. YY1 depletion enhanced the radiosensitivity of ESCC in vitro and in vivo. Multi-group sequencing showed that downregulation of YY1 inhibited the transcriptional activity of Kinesin Family Member 3B (KIF3B), which further activated the Hippo signaling pathway by interacting with Integrin-beta1 (ITGB1). Once the Hippo pathway was activated, its main effector, Yes-associated protein 1 (YAP1), was phosphorylated in the cytoplasm and its expression reduced in the nucleus, thus enhancing the radiosensitivity by regulating its targeted genes. Our study provides new insights into the mechanisms underlying ESCC radioresistance and highlights the potential role of YY1 as a therapeutic target for ESCC.

Anaplastic thyroid cancer cells reduce CD71 levels to increase iron overload tolerance

BACKGROUND

Follicular thyroid cancer (FTC) is a prevalent form of differentiated thyroid cancer, whereas anaplastic thyroid cancer (ATC) represents a rare, fast-growing, undifferentiated, and highly aggressive tumor, posing significant challenges for eradication. Ferroptosis, an iron-dependent cell death mechanism driven by the excessive production of reactive oxygen species and subsequent lipid peroxidation, emerges as a promising therapeutic strategy for cancer. It has been observed that many cancer cells exhibit sensitivity to ferroptosis, while some other histotypes appear to be resistant, by counteracting the metabolic changes and oxidative stress induced by iron overload.

METHODS

Here we used human biopsies and in vitro approaches to analyse the effects of iron-dependent cell death. We assessed cell proliferation and viability through MTT turnover, clonogenic assays, and cytofluorimetric-assisted analysis. Lipid peroxidation assay and western blot were used to analyse molecular mechanisms underlying ferroptosis modulation. Two distinct thyroid cancer cell lines, FTC-133 (follicular) and 8505C (anaplastic), were utilized. These cell lines were exposed to ferroptosis inducers, Erastin and RSL3, while simulating an iron overload condition using ferric ammonium citrate.

RESULTS

Our evidence suggests that FTC-133 cell line, exposed to iron overload, reduced their viability and showed increased ferroptosis. In contrast, the 8505C cell line seems to better tolerate ferroptosis, responding by modulating CD71, which is involved in iron internalization and seems to have a role in resistance to iron overload and consequently in maintaining cell viability.

CONCLUSIONS

The differential tolerance to ferroptosis observed in our study may hold clinical implications, particularly in addressing the unmet therapeutic needs associated with ATC treatment, where resistance to ferroptosis appears more pronounced compared to FTC.

Ginsenoside Rg5 promotes wound healing in diabetes by reducing the negative regulation of SLC7A11 on the efferocytosis of dendritic cells

Background: ginsenoside Rg5 is a rare ginsenoside with known hypoglycemic effects in diabetic mice. This study aimed to explore the effects of ginsenoside Rg5 on skin wound-healing in the Leprdb/db mutant (db/db) mice (C57BL/KsJ background) model and the underlying mechanisms.

Methods

Seven-week-old male C57BL/6J, SLC7A11-knockout (KO), the littermate wild-type (WT), and db/db mice were used for in vivo and ex vivo studies.

Results

Ginsenoside Rg5 provided through oral gavage in db/db mice significantly alleviated the abundance of apoptotic cells in the wound areas and facilitated skin wound healing. 50 μM ginsenoside Rg5 treatment nearly doubled the efferocytotic capability of bone marrow-derived dendritic cells (BMDCs) from db/db mice. It also reduced NF-κB p65 and SLC7A11 expression in the wounded areas of db/db mice dose-dependently. Ginsenoside Rg5 physically interacted with SLC7A11 and suppressed the cystine uptake and glutamate secretion of BMDCs from db/db and SLC7A11-WT mice but not in BMDCs from SLC7A11-KO mice. In BMDCs and conventional type 1 dendritic cells (cDC1s), ginsenoside Rg5 reduced their glycose storage and enhanced anaerobic glycolysis. Glycogen phosphorylase inhibitor CP-91149 almost abolished the effect of ginsenoside Rg5 on promoting efferocytosis. Conclusion: ginsenoside Rg5 can suppress the expression of SLC7A11 and inhibit its activity via physical binding. These effects collectively alleviate the negative regulations of SLC7A11 on anaerobic glycolysis, which fuels the efferocytosis of dendritic cells. Therefore, ginsenoside Rg5 has a potential adjuvant therapeutic reagent to support patients with wound-healing problems, such as diabetic foot ulcers.

Brusatol induces ferroptosis in oesophageal squamous cell carcinoma by repressing GSH synthesis and increasing the labile iron pool via inhibition of the NRF2 pathway

Brusatol (Bru), a bioactive compound found in Brucea sumatrana, exerts antitumour effects on several malignancies. However, the role and molecular mechanism of Bru in squamous cell carcinoma of the oesophagus (ESCC) remain unclear. Here, we found that Bru decreased the survival of ESCC cells. Subsequently, the ferroptosis inhibitors, deferoxamine and liproxstatin-1, rescued Bru-induced cell death, indicating that ferroptosis plays a major role in Bru-induced cell death. Furthermore, Bru promoted lipid peroxidation, glutathione (GSH) depletion, and ferrous iron overload in vitro. Consistent with these in vitro results, Bru significantly inhibited tumour growth in KYSE150 xenograft nude mice by triggering ferroptosis. Mechanistically, nuclear factor E2-related factor 2 (NRF2) inactivation via increased ubiquitin-proteasome degradation was found to be a vital determinant of ferroptosis induced by Bru. Notably, Bru significantly decreases GSH synthesis, iron storage, and efflux by downregulating the expression of NRF2 target genes (glutamate-cysteine ligase catalytic subunit (GCLC), solute carrier family 7 member 11 (SLC7A11), ferritin heavy chain 1 (FTH1), and solute carrier family 40 member 1 (SLC40A1)), resulting in the accumulation of lethal lipid-based reactive oxygen species (ROS) and intracellular enrichment of chelated iron. Taken together, our findings indicate that ferroptosis is a novel mechanism underlying Bru-induced antitumour activity and will hopefully provide a valuable compound for ESCC treatment.

Glutamine metabolism in tumor metastasis: Genes, mechanisms and the therapeutic targets

Cancer cells frequently change their metabolism from aerobic glycolysis to lipid metabolism and amino acid metabolism to adapt to the malignant biological behaviours of infinite proliferation and distant metastasis. The significance of metabolic substances and patterns in tumour cell metastasis is becoming increasingly prominent. Tumour metastasis involves a series of significant steps such as the shedding of cancer cells from a primary tumour, resistance to apoptosis, and colonisation of metastatic sites. However, the role of glutamine in these processes remains unclear. This review summarises the key enzymes and transporters involved in glutamine metabolism that are related to the pathogenesis of malignant tumour metastasis. We also list the roles of glutamine in resisting oxidative stress and promoting immune escape. Finally, the significance of targeting glutamine metabolism in inhibiting tumour metastasis was proposed, research in this field improving our understanding of amino acid metabolism rewiring and simultaneously bringing about new and exciting therapeutic prospects.

NRF2 Antagonizes HIV-1 Tat and Methamphetamine-Induced BV2 Cell Ferroptosis by Regulating SLC7A11

Methamphetamine (METH) and HIV-1 lead to oxidative stress and their combined effect increases the risk of HIV-associated neurocognitive disorder (HAND), which may be related to the synergistic ferroptotic impairment in microglia. Ferroptosis is a redox imbalance cell damage associated with iron overload that is linked to the pathogenic processes of METH and HIV-1. NRF2 is an antioxidant transcription factor that plays a protective role in METH and HIV-1-induced neurotoxicity, but its mechanism has not been fully elucidated. To explore the role of ferroptosis in METH abuse and HIV-1 infection and the potential role of NRF2 in this process, we conducted METH and HIV-1 Tat exposure models using the BV2 microglia cells. We found that METH and HIV-1 Tat reduced the expression of ferroptotic protein GPX4 and the cell viability and enhanced the expression of P53 and the level of ferrous iron, while the above indices were significantly improved with pretreatment of ferrostatin-1. In addition, NRF2 knockdown accelerated METH and HIV-1 Tat-induced BV2 cell ferroptosis accompanied by decreased expression of SLC7A11. On the contrary, NRF2 stimulation significantly increased the expression of SLC7A11 and attenuated ferroptosis in cells. In summary, our study indicates that METH and HIV-1 Tat synergistically cause BV2 cell ferroptosis, while NRF2 antagonizes BV2 cell ferroptotic damage induced by METH and HIV-1 Tat through regulation of SLC7A11. Overall, this study provides potential therapeutic strategies for the treatment of neurotoxicity caused by METH and HIV-1 Tat, providing a theoretical basis and new targets for the treatment of HIV-infected drug abusers.

Exosome-mediated metabolic reprogramming: Implications in esophageal carcinoma progression and tumor microenvironment remodeling

Esophageal carcinoma is among the most fatal malignancies with increasing incidence globally. Tumor onset and progression can be driven by metabolic reprogramming, especially during esophageal carcinoma development. Exosomes, a subset of extracellular vesicles, display an average size of ∼100 nanometers, containing multifarious components (nucleic acids, proteins, lipids, etc.). An increasing number of studies have shown that exosomes are capable of transferring molecules with biological functions into recipient cells, which play crucial roles in esophageal carcinoma progression and tumor microenvironment that is a highly heterogeneous ecosystem through rewriting the metabolic processes in tumor cells and environmental stromal cells. The review introduces the reprogramming of glucose, lipid, amino acid, mitochondrial metabolism in esophageal carcinoma, and summarize current pharmaceutical agents targeting such aberrant metabolism rewiring. We also comprehensively overview the biogenesis and release of exosomes, and recent advances of exosomal cargoes and functions in esophageal carcinoma and their promising clinical application. Moreover, we discuss how exosomes trigger tumor growth, metastasis, drug resistance, and immunosuppression as well as tumor microenvironment remodeling through focusing on their capacity to transfer materials between cells or between cells and tissues and modulate metabolic reprogramming, thus providing a theoretical reference for the design potential pharmaceutical agents targeting these mechanisms. Altogether, our review attempts to fully understand the significance of exosome-based metabolic rewriting in esophageal carcinoma progression and remodeling of the tumor microenvironment, bringing novel insights into the prevention and treatment of esophageal carcinoma in the future.

BBOX1-AS1: A novel oncogenic long non-coding RNA in human cancers

Long non-coding RNAs (lncRNAs) are transcripts that contain more than 200 nucleotides. Despite the fact that they cannot encode proteins, many studies have identified roles they play in human cancers through diverse mechanisms. BBOX1-AS1, an oncogenic lncRNA, has recently been demonstrated to participate in tumorigenesis and progression of numerous cancers. Experimental evidence has determined that it participates in diverse biological process, including cell proliferation, invasion, migration, and apoptosis. The dysregulation of BBOX1-AS1 exerts its oncogenicity by acting as a competitive endogenous RNA (ceRNA) or by directly impacting downstream molecules and signaling pathways. Here we summarize the current understanding of the biological functions and clinical significance of BBOX1-AS1 for human cancers.

Recent advances of ferroptosis in tumor: From biological function to clinical application

Ferroptosis is a recently recognized form of cell death with distinct features in terms of morphology, biochemistry, and molecular mechanisms. Unlike other types of cell death, ferroptosis is characterized by iron dependence, reactive oxygen species accumulation and lipid peroxidation. Recent studies have demonstrated that selective autophagy plays a vital role in the induction of ferroptosis, including ferritinophagy, lipophagy, clockophagy, and chaperone-mediated autophagy. Emerging evidence has indicated the involvement of ferroptosis in tumorigenesis through regulating various biological processes, including tumor growth, metastasis, stemness, drug resistance, and recurrence. Clinical and preclinical studies have found that novel therapies targeting ferroptosis exert great potential in the treatment of tumors. This review provides a comprehensive overview of the molecular mechanisms in ferroptosis, especially in autophagy-driven ferroptosis, discusses the recent advances in the biological roles of ferroptosis in tumorigenesis, and highlights the application of novel ferroptosis-targeted therapies in the clinical treatment of tumors.

The role of novel programmed cell death in head and neck squamous cell carcinoma: from mechanisms to potential therapies

Head and neck squamous cell carcinoma (HNSCC) is a common oral cancer with poor prognosis and for which no targeted therapeutic strategies are currently available. Accumulating evidence has demonstrated that programmed cell death (PCD) is essential in the development of HNSCC as a second messenger. PCD can be categorized into numerous different subroutines: in addition to the two well-known types of apoptosis and autophagy, novel forms of programmed cell death (e.g., necroptosis, pyroptosis, ferroptosis, and NETosis) also serve as key alternatives in tumorigenesis. Cancer cells are not able to avoid all types of cell death simultaneously, since different cell death subroutines follow different regulatory pathways. Herein, we summarize the roles of novel programmed cell death in tumorigenesis and present our interpretations of the molecular mechanisms with a view to the development of further potential therapies.

Nrf2 signaling pathway: current status and potential therapeutic targetable role in human cancers

Cancer is a borderless global health challenge that continues to threaten human health. Studies have found that oxidative stress (OS) is often associated with the etiology of many diseases, especially the aging process and cancer. Involved in the OS reaction as a key transcription factor, Nrf2 is a pivotal regulator of cellular redox state and detoxification. Nrf2 can prevent oxidative damage by regulating gene expression with antioxidant response elements (ARE) to promote the antioxidant response process. OS is generated with an imbalance in the redox state and promotes the accumulation of mutations and genome instability, thus associated with the establishment and development of different cancers. Nrf2 activation regulates a plethora of processes inducing cellular proliferation, differentiation and death, and is strongly associated with OS-mediated cancer. What's more, Nrf2 activation is also involved in anti-inflammatory effects and metabolic disorders, neurodegenerative diseases, and multidrug resistance. Nrf2 is highly expressed in multiple human body parts of digestive system, respiratory system, reproductive system and nervous system. In oncology research, Nrf2 has emerged as a promising therapeutic target. Therefore, certain natural compounds and drugs can exert anti-cancer effects through the Nrf2 signaling pathway, and blocking the Nrf2 signaling pathway can reduce some types of tumor recurrence rates and increase sensitivity to chemotherapy. However, Nrf2's dual role and controversial impact in cancer are inevitable consideration factors when treating Nrf2 as a therapeutic target. In this review, we summarized the current state of biological characteristics of Nrf2 and its dual role and development mechanism in different tumor cells, discussed Keap1/Nrf2/ARE signaling pathway and its downstream genes, elaborated the expression of related signaling pathways such as AMPK/mTOR and NF-κB. Besides, the main mechanism of Nrf2 as a cancer therapeutic target and the therapeutic strategies using Nrf2 inhibitors or activators, as well as the possible positive and negative effects of Nrf2 activation were also reviewed. It can be concluded that Nrf2 is related to OS and serves as an important factor in cancer formation and development, thus provides a basis for targeted therapy in human cancers.

Regulation of m6A modification on ferroptosis and its potential significance in radiosensitization

Radiotherapy is often used to treat various types of cancers, but radioresistance greatly limits the clinical efficiency. Recent studies have shown that radiotherapy can lead to ferroptotic cancer cell deaths. Ferroptosis is a new type of programmed cell death caused by excessive lipid peroxidation. The induction of ferroptosis provides a potential therapeutic strategy for radioresistance. As the most common post-transcriptional modification of mRNA, m6A methylation is widely involved in the regulation of various physiopathological processes by regulating RNA function. Dynamic m6A modification controlled by m6A regulatory factors also affects the susceptibility of cells to ferroptosis, thereby determining the radiosensitivity of tumor cells to radiotherapy. In this review, we summarize the mechanism and significance of radiotherapy induced ferroptosis, analyze the regulatory characteristics of m6A modification on ferroptosis, and discuss the possibility of radiosensitization by enhancing m6A-mediated ferroptosis. Clarifying the regulation of m6A modification on ferroptosis and its significance in the response of tumor cells to radiotherapy will help us identify novel targets to improve the efficacy of radiotherapy and reduce or overcome radioresistance.

New mechanisms and biomarkers of lymph node metastasis in cervical cancer: reflections from plasma proteomics

OBJECTIVE

Lymph node metastasis (LNM) and lymphatic vasculature space infiltration (LVSI) in cervical cancer patients indicate a poor prognosis, but satisfactory methods for diagnosing these phenotypes are lacking. This study aimed to find new effective plasma biomarkers of LNM and LVSI as well as possible mechanisms underlying LNM and LVSI through data-independent acquisition (DIA) proteome sequencing.

METHODS

A total of 20 cervical cancer plasma samples, including 7 LNM-/LVSI-(NC), 4 LNM-/LVSI + (LVSI) and 9 LNM + /LVSI + (LNM) samples from a cohort, were subjected to DIA to identify differentially expressed proteins (DEPs) for LVSI and LNM. Subsequently, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed for DEP functional annotation. Protein-protein interaction (PPI) and weighted gene coexpression network analysis (WGCNA) were used to detect new effective plasma biomarkers and possible mechanisms.

RESULTS

A total of 79 DEPs were identified in the cohort. GO and KEGG analyses showed that DEPs were mainly enriched in the complement and coagulation pathway, lipid and atherosclerosis pathway, HIF-1 signal transduction pathway and phagosome and autophagy. WGCNA showed that the enrichment of the green module differed greatly between groups. Six interesting core DEPs (SPARC, HPX, VCAM1, TFRC, ERN1 and APMAP) were confirmed to be potential plasma diagnostic markers for LVSI and LNM in cervical cancer patients.

CONCLUSION

Proteomic signatures developed in this study reflected the potential plasma diagnostic markers and new possible pathogenesis mechanisms in the LVSI and LNM of cervical cancer.

Reinforcing the immunogenic cell death to enhance cancer immunotherapy efficacy

Immunogenic cell death (ICD) has been a revolutionary modality in cancer treatment since it kills primary tumors and prevents recurrent malignancy simultaneously. ICD represents a particular form of cancer cell death accompanied by production of damage-associated molecular patterns (DAMPs) that can be recognized by pattern recognition receptors (PRRs), which enhances infiltration of effector T cells and potentiates antitumor immune responses. Various treatment methods can elicit ICD involving chemo- and radio-therapy, phototherapy and nanotechnology to efficiently convert dead cancer cells into vaccines and trigger the antigen-specific immune responses. Nevertheless, the efficacy of ICD-induced therapies is restrained due to low accumulation in the tumor sites and damage of normal tissues. Thus, researchers have been devoted to overcoming these problems with novel materials and strategies. In this review, current knowledge on different ICD modalities, various ICD inducers, development and application of novel ICD-inducing strategies are summarized. Moreover, the prospects and challenges are briefly outlined to provide reference for future design of novel immunotherapy based on ICD effect.

Aloe-emodin alleviates doxorubicin-induced cardiotoxicity via inhibition of ferroptosis

Aloe-emodin (AE), a novel ferroptosis inhibitor, alleviates the doxorubicin (DOX)-induced cardiotoxicity in H9c2 rat cardiomyocytes. The inhibition of ferroptosis and the protective effect against cardiotoxicity were evaluated via MTT assay in H9c2 cells. The molecular mechanism of action (MOA) of nuclear factor erythroid 2-related factor 2 (Nrf2) activation, including transactivation of multiple downstream cytoprotective genes, were further assessed by Western blot, luciferase reporter assay and qRT-PCR analyses. Fluorescent imaging was performed to detect the change of intracellular reactive oxygen species, mitochondrial membrane potential and lipid peroxidation. In addition, an infrared spectroscopy was employed to detect the AE-Fe (II) complex. AE, alleviates oxidative stress in DOX-induced H9c2 cells by activating Nrf2 and increasing the expression of Nrf2 downstream antioxidant genes, SLC7A11 and GPX4. Furthermore, AE complexes bivalent iron and regulates the intracellular iron-related genes. In conclusion, the discovery of AE as a novel ferroptosis inhibitor and its MOA provides a new perspective for further exploration of cardio-protective agents in cancer patients during chemotherapy.

Ferroptosis, Necroptosis, and Pyroptosis in Gastrointestinal Cancers: The Chief Culprits of Tumor Progression and Drug Resistance

In recent years, the incidence of gastrointestinal cancers is increasing, particularly in the younger population. Effective treatment is crucial for improving patients' survival outcomes. Programmed cell death, regulated by various genes, plays a fundamental role in the growth and development of organisms. It is also critical for maintaining tissue and organ homeostasis and takes part in multiple pathological processes. In addition to apoptosis, there are other types of programmed cell death, such as ferroptosis, necroptosis, and pyroptosis, which can induce severe inflammatory responses. Notably, besides apoptosis, ferroptosis, necroptosis, and pyroptosis also contribute to the occurrence and development of gastrointestinal cancers. This review aims to provide a comprehensive summary on the biological roles and molecular mechanisms of ferroptosis, necroptosis, and pyroptosis, as well as their regulators in gastrointestinal cancers and hope to open up new paths for tumor targeted therapy in the near future.

Mechanisms of radiotherapy resistance and radiosensitization strategies for esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is the sixth most common cause of cancer-related mortality worldwide, with more than half of them occurred in China. Radiotherapy (RT) has been widely used for treating ESCC. However, radiation-induced DNA damage response (DDR) can promote the release of cytokines and chemokines, and triggers inflammatory reactions and changes in the tumor microenvironment (TME), thereby inhibiting the immune function and causing the invasion and metastasis of ESCC. Radioresistance is the major cause of disease progression and mortality in cancer, and it is associated with heterogeneity. Therefore, a better understanding of the radioresistance mechanisms may generate more reversal strategies to improve the cure rates and survival periods of ESCC patients. We mainly summarized the possible mechanisms of radioresistance in order to reveal new targets for ESCC therapy. Then we summarized and compared the current strategies to reverse radioresistance.

Long noncoding RNA CASC11 suppresses sorafenib-triggered ferroptosis via stabilizing SLC7A11 mRNA in hepatocellular carcinoma cells

As a frontline treatment for patients with advanced hepatocellular carcinoma (HCC), sorafenib is an effective drug approved by the Food and Drug Administration (FDA). Ferroptosis, a newly defined programmed cell death process with the hallmark of the accumulation of iron-dependent lipid peroxides, can be induced by sorafenib treatment. Our previous study identified oncogenic roles of long noncoding RNA (lncRNA) Cancer susceptibility candidate 11 (CASC11) in HCC progression. However, the relationship between CASC11 and sorafenib-induced ferroptosis in HCC remains unclear. In the present study, we aim to investigate the role of CASC11 in sorafenib-induced ferroptosis in HCC cell lines and determine the involved molecular mechanisms. Here, we demonstrated that sorafenib decreased CASCL11 expression. Knockdown of CASC11 enhanced sorafenib-induced ferroptosis, while overexpression of CASC11 exerted the opposite effect in HCC cells. Moreover, CASC11 led to the accumulation of intracellular malondialdehyde (MDA), lipid reactive oxygen species (ROS) and Fe2+ while depleting glutathione (GSH), thereby suppressing sorafenib-induced ferroptosis and cell death. Ferrostatin-1 (Ferr-1), a ferroptosis inhibitor, reversed the enhanced anticancer effect of sorafenib caused by the silence of CASC11 in HCC cells. Mechanistically, CASC11 upregulated the expression of solute carrier family 7 member 11 (SLC7A11) which is critical for ferroptosis inhibition. CASC11 associated with and stabilized SLC7A11 mRNA. In summary, our data revealed, for the first time, that CASC11 inhibits the sorafenib-induced ferroptosis in HCC cells via regulating SLC7A11, providing a new basis for clinical therapeutic strategies for patients with HCC.

Unraveling the Complexity of Regulated Cell Death in Esophageal Cancer: from Underlying Mechanisms to Targeted Therapeutics

Esophageal cancer (EC) is the sixth most common and the seventh most deadly malignancy of the digestive tract, representing a major global health challenge. Despite the availability of multimodal therapeutic strategies, the existing EC treatments continue to yield unsatisfactory results due to their limited efficacy and severe side effects. Recently, knowledge of the subroutines and molecular mechanisms of regulated cell death (RCD) has progressed rapidly, enhancing the understanding of key pathways related to the occurrence, progression, and treatment of many types of tumors, including EC. In this context, the use of small-molecule compounds to target such RCD subroutines has emerged as a promising therapeutic strategy for patients with EC. Thus, in this review, we firstly discussed the risk factors and prevention of EC. We then outlined the established treatment regimens for patients with EC. Furthermore, we not only briefly summarized the mechanisms of five best studied subroutines of RCD related to EC, including apoptosis, ferroptosis, pyroptosis, necroptosis and autophagy, but also outlined the recent advances in the development of small-molecule compounds and long non-coding RNA (lncRNA) targeting the abovementioned RCD subroutines, which may serve as a new therapeutic strategy for patients with EC in the future.