Research progress on SLC7A11 in the regulation of cystine/cysteine metabolism in tumors

Quercetin and microRNA Interplay in Apoptosis Regulation: A New Therapeutic Strategy for Cancer?

Cancer is known as a global problem for the health and economy. Following cancer onset, apoptosis is the primary mechanism countering the tumor cells' growth. Most anticancer agents initiate apoptosis to remove tumor cells. Phytochemicals have appeared as a beneficial treatment option according to their less adverse effects. In recent decades, quercetin has been highlighted due to its high pharmacological benefits, and various literature has suggested it as a potential anti-proliferative agent against different kinds of cancers. The microRNAs (miRNAs) play key roles in cancer treatment, progression, and apoptosis. This review reviewed the effect of quercetin on miRNAs contributing to the induction or inhibition of apoptosis in cancers.

SLC7A11 Expression Is Up-Regulated in HPV- and Tobacco-Associated Lung Cancer

High-risk human papillomaviruses (HR-HPVs) are the etiological agents of cervical, anogenital, and a subset of oropharyngeal cancers. In addition, HR-HPVs have been detected in lung carcinomas worldwide, even though the role of these viruses in this type of cancer is not fully understood. This study evaluated the presence of HPV in a cohort of 204 lung cancer cases by multiplex polymerase chain reaction (PCR)-Luminex. In addition, we used transcriptomic approaches to characterize the HPV-associated gene expression profile in the context of tobacco-smoke-associated lung cancer. HPV16 was detected in 8/204 lung carcinomas (4.0%). Through a significance analysis of microarrays (SAM) analysis, we found that the solute carrier family 7-member 11 (SLC7A11/xCT) gene (an antiporter that mediates the uptake of extracellular cystine) is up-regulated in tobacco-smoke- and HPV-associated lung cancers. In addition, SLC7A11 up-regulation correlates with both HR-HPV16 E6/E7 expression and tobacco smoke exposure in lung epithelial cells. Furthermore, we found decreased survival in HPV/SLC7A11-positive patients with lung cancer when compared to HPV/SLC7A11-negative cases. Thus, this study suggests that SLC7A11 up-regulation is associated with both HPV-positive and tobacco-smoke-associated lung carcinomas, with a potential association with clinical prognosis.

Integrated analysis of disulfidptosis-related genes SLC7A11, SLC3A2, RPN1 and NCKAP1 across cancers

Disulfidptosis, a newly identified form of regulated cell death associated with disruption of disulfide bond formation in the endoplasmic reticulum, involves the dysregulation of disulfidptosis-related genes (DRGs) that may contribute to cancer development and progression. However, the molecular mechanisms and clinical implications of DRGs in different cancer types remain poorly characterized. Therefore, in this comprehensive study, we investigated the expression, prognostic value, and functional roles of four recently identified DRGs (SLC7A11, SLC3A2, RPN1, and NCKAP1) across various cancers. Especially, in clinical samples of glioblastoma, we found that RPN1 was significantly correlated with patient survival. Through mutation landscape analysis, we identified diverse missense mutations in these DRGs, with NCKAP1 exhibiting the highest mutation frequency (5.9% in skin cutaneous melanoma). Additionally, we observed positive correlations between these DRGs and tumor stemness (DNAss DNA stemness score and RNAss RNA stemness score) as well as RNA modifications, particularly m6A modification, in several cancer types. Furthermore, high expression of SLC7A11, RPN1, and NCKAP1 was positively associated with infiltration of T-helper type 2 (Th2) cells in various cancers, while high expression of SLC7A11, SLC3A2, and RPN1 correlated with tumor mutational burden (TMB) in 10, 4, and 8 tumor types, respectively. Utilizing a protein-protein interaction network, we identified the RHO GTPases Activate WASPs and WAVEs pathway as significantly enriched, suggesting the involvement of these DRGs in cancer-related signaling pathways. Collectively, our findings provide novel insights into the molecular mechanisms and clinical implications of DRGs in pan-cancer, highlighting their potential as biomarkers and therapeutic targets for cancer treatment.

Integrated stress response-upregulated mitochondrial SLC1A5var enhances glucose dependency in human breast cancer cells in vitro

Breast cancer is the most commonly diagnosed cancer among women. The growth of triple-negative breast cancer (TNBC) cells is glucose-dependent. The integrated stress response (ISR) is a cellular stress response to glucose depletion. The ISR-solute carrier family 7 member 11 pathway is activated during glucose depletion and contributes to glucose dependence by decreasing intracellular glutamate levels. Solute carrier family 1 member 5 (SLC1A5) and the mitochondrial solute carrier family 1 member 5 variant (SLC1A5var) are glutamine transporters that play essential roles in the reprogramming of cancer metabolism. However, whether ISR can regulate mitochondrial SLC1A5var expression and further affect glucose dependence remains unclear. Glucose depletion-, oligomycin-, and salubrinal-activated activating transcription factor-4 (ATF4) induced SLC1A5var expression. ATF4 is critical for SLC1A5var regulation, as it binds to specific regulatory elements in its promoter. SLC1A5var knockdown decreases glucose depletion-induced cell death, whereas SLC1A5var overexpression increases glucose depletion-induced cell death in TNBC cells. SLC1A5var knockdown reduced cancer cell proliferation, colony formation, and migration, whereas SLC1A5var overexpression increased cell proliferation and migration. Moreover, the knockdown of SLC1A5var reduces the oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) while increasing the maximal OCR and ECAR under glucose depletion. These results suggest that activated ISR-induced increased expression of SLC1A5var may regulate mitochondrial oxidative phosphorylation and glycolytic metabolic characteristics to enhance glucose depletion-induced cell death. In conclusion, SLC1A5var plays a vital role in metabolic reprogramming and may be a potential target for breast cancer treatment.

Hypoxia-inducible factor-1 as targets for neuroprotection : from ferroptosis to Parkinson's disease

BACKGROUND

Parkinson's disease (PD) is a neurodegenerative disease characterized by motor paralysis, tremor,and cognitive impairment. Risk factors such as brain hypoxia caused by aging and abnormal expression of HIF-1α areconsidered to be key to the development of PD, including α-synuclein accumulation and ferroptosis. However, therelationship between HIF-1α signaling and ferroptosis in PD has not been elucidated. The stable expression of HIF-1αinhibits the pathological development of PD. Aging aggravates PD pathology by promoting α-synuclein accumulationand oxidative stress.

METHODS

The literature on lipid peroxidation, oxidative stress, iron metabolism and other key factors in Parkinson'sdisease in recent years was reviewed through a variety of literature search channels, such as PubMed and Elsevier.

RESULTS

HIF-1α mediated ferroptosis through oxidative stress and GPX4-GSH system. HIF-1α mediates ferroptosisthrough Keap1-Nrf2-ARE, Grx3 and Grx4. HIF-1α mediates ferroptosis through iron metabolism.

CONCLUSION

This article reviews the oxygen-dependent regulatory mechanism of HIF-1α and its role in cerebralhypoxia homeostasis. Studies in the past decade have shown that Hif-1α mediated ferroptosis is important in PD.HIF-1α has a dual role, depending on the degree of cellular hypoxia and the environment. The equilibrium complexityneeds to be explained, and the role of ferroptosis needs to be investigated. The literature shows that the stabilizationof HIF-1α with PHD inhibitors and the combination of antioxidants and iron chelators are potential therapeuticdirections. In the future, the optimal use time and dose of inhibitors should be studied to improve the efficacy.

The splicing factor SF3B1 confers ferroptosis resistance and promotes lung adenocarcinoma progression via upregulation of SLC7A11

This study aimed to investigate the expression of SF3B1 in non-small cell lung cancer, and its clinical significance, biological function, and molecular mechanisms. SF3B1 mRNA and protein levels were elevated in both lung squamous cell carcinoma and lung adenocarcinoma (LUAD) tissues based on TCGA data and immunohistochemistry. Notably, high SF3B1 expression in LUAD was significantly associated with increased lymph node metastasis. Functional experiments involving SF3B1 knockdown and overexpression demonstrated that SF3B1 facilitated the proliferation, invasion, and migration of LUAD cells. Additionally, the SF3B1 inhibitor pladienolide-B attenuated the aggressive behavior of LUAD cells both in vitro and in vivo. RNA sequencing analysis indicated that differentially expressed genes in the SF3B1 knockdown and SF3B1 inhibitor groups were enriched in ferroptosis-related pathways compared to their respective control groups. The antiferroptotic role of SF3B1 in LUAD cells was validated by detecting glutathione depletion, lipid peroxidation, and observing morphological changes using transmission electron microscopy. This process was confirmed to be independent of apoptosis and autophagy, as evidenced by the effects of the ferroptosis inducer erastin, the apoptosis inhibitor Z-VAD-FMK, and the autophagy inhibitor 3-methyladenine. Rescue experiments indicated that the antiferroptotic role of SF3B1 in LUAD is partially mediated by upregulating the expression of SLC7A11.

Emerging insights: miRNA modulation of ferroptosis pathways in lung cancer

The newly discovered programmed iron-dependent necrosis, ferroptosis, is a novel pathway that is controlled by iron-dependent lipid peroxidation and cellular redox changes. It can be triggered intrinsically by low antioxidant enzyme activity or extrinsically by blocking amino acid transporters or activating iron transporters. The induction of ferroptosis involves the activation of specific proteins, suppression of transporters, and increased endoplasmic reticulum (ER) stress (a condition in which the ER, a crucial organelle involved in protein folding and processing, becomes overwhelmed by an accumulation of misfolded or unfolded proteins. This situation disrupts the normal functioning of the ER, leading to a cellular stress response known as the unfolded protein response), leading to lipid peroxidation byproduct accumulation and toxic reactive oxygen species (ROS), which are highly reactive molecules derived from diatomic oxygen and include various forms such as superoxide (O₂⁻), hydroxyl radicals (•OH), and hydrogen peroxide (H₂O₂). Ferroptosis is closely associated with signaling molecules in lung cancer, including epidermal growth factor receptor (EGFR), mitogen-activated protein kinase (MAPK), hypoxia-inducible factor 1-alpha (HIF-1α), and P53, and is regulated by epigenetic factors such as microRNAs (miRNAs). miRNAs are small non-coding RNA molecules that regulate gene expression by binding to target messenger RNAs (mRNAs), leading to translational repression or degradation. Several miRNAs have been found to modulate ferroptosis by targeting key genes involved in iron metabolism, lipid peroxidation, and antioxidant defense pathways. The research on ferroptosis has expanded to target its role in lung cancer treatment and resistance prevention. This review encapsulates the significance of ferroptosis in lung cancer. Understanding the mechanisms and implications of ferroptosis in lung cancer cells may lead to targeted therapies exploiting cancer cell vulnerabilities to ferroptosis Also, improving treatment outcomes, and overcoming resistance.

The epigenetic modification of DNA methylation in neurological diseases

Methylation, a key epigenetic modification, is essential for regulating gene expression and protein function without altering the DNA sequence, contributing to various biological processes, including gene transcription, embryonic development, and cellular functions. Methylation encompasses DNA methylation, RNA methylation and histone modification. Recent research indicates that DNA methylation is vital for establishing and maintaining normal brain functions by modulating the high-order structure of DNA. Alterations in the patterns of DNA methylation can exert significant impacts on both gene expression and cellular function, playing a role in the development of numerous diseases, such as neurological disorders, cardiovascular diseases as well as cancer. Our current understanding of the etiology of neurological diseases emphasizes a multifaceted process that includes neurodegenerative, neuroinflammatory, and neurovascular events. Epigenetic modifications, especially DNA methylation, are fundamental in the control of gene expression and are critical in the onset and progression of neurological disorders. Furthermore, we comprehensively overview the role and mechanism of DNA methylation in in various biological processes and gene regulation in neurological diseases. Understanding the mechanisms and dynamics of DNA methylation in neural development can provide valuable insights into human biology and potentially lead to novel therapies for various neurological diseases.

Ferroptosis in radiation-induced brain injury: roles and clinical implications

Radiation-induced brain injury (RBI) presents a significant challenge for patients undergoing radiation therapy for head, neck, and intracranial tumors. This review aims to elucidate the role of ferroptosis in RBI and its therapeutic implications. Specifically, we explore how ferroptosis can enhance the sensitivity of tumor cells to radiation while also examining strategies to mitigate radiation-induced damage to normal brain tissues. By investigating the mechanisms through which radiation increases cellular reactive oxygen species (ROS) and initiates ferroptosis, we aim to develop targeted therapeutic strategies that maximize treatment efficacy and minimize neurotoxicity. The review highlights key regulatory factors in the ferroptosis pathway, including glutathione peroxidase 4 (GPX4), cystine/glutamate antiporter system Xc- (System Xc-), nuclear factor erythroid 2-related factor 2 (NRF2), Acyl-CoA synthetase long-chain family member 4 (ACSL4), and others, and their interactions in the context of RBI. Furthermore, we discuss the clinical implications of modulating ferroptosis in radiation therapy, emphasizing the potential for selective induction of ferroptosis in tumor cells and inhibition in healthy cells. The development of advanced diagnostic tools and therapeutic strategies targeting ferroptosis offers a promising avenue for enhancing the safety and efficacy of radiation therapy, underscoring the need for further research in this burgeoning field.

CircPDSS1 (hsa_circ_0017998) silencing induces ferroptosis in non-small-cell lung cancer cells by modulating the miR-137/SLC7A11/GPX4/GCLC axis

BACKGROUND

Circular RNAs (circRNAs) regulate the tumorigenesis of non-small-cell lung cancer (NSCLC). CircPDSS1 (hsa_circ_0017998) has been newly discovered, and its role in NSCLC remains elusive. We aimed to investigate the functional roles and downstream targets of circPDSS1 in NSCLC cells.

MATERIALS AND METHODS

Cellular viabilities were measured through the Cell Counting Kit-8 (CCK-8) assay, whereas cell death was assessed through flow cytometry. The lactate dehydrogenase activity, malondialdehyde levels, ferrous iron, and reactive oxygen species were measured using commercial assay kits. The interaction between circPDSSA/ microRNA-137 (miR-137) and miR-137/solute carrier family 7 member 11 (SLC7A11) was assayed through a dual luciferase activity assay. Finally, the mRNA and protein levels were measured using real-time reverse transcriptase-polymerase chain reaction and western blots, respectively.

RESULTS

CircPDSS1 expression was upregulated in NSCLC cells, compared with healthy lung cells. CircPDSS1 silencing suppressed the viability of NSCLC cells. Additionally, circPDSS1 knockdown induced ferroptosis rather than other types of cell death in NSCLC cells. Mechanically, circPDSS1 functions as a "sponge" to inversely control miR-137 expression, which directly targets SLC7A11. Moreover, circPDSS1 silencing causes the downregulation of glutathione peroxidase 4 (GPX4) and glutamate-cysteine ligase catalytic subunit (GCLC).

CONCLUSIONS

Targeting the circPDSS1/miR-137/SLC7A11/GPX4/GCLC axis may be a promising strategy to kill NSCLC cells.

Decoding the Role of O-GlcNAcylation in Hepatocellular Carcinoma

Post-translational modifications (PTMs) influence protein functionality by modulating protein stability, localization, and interactions with other molecules, thereby controlling various cellular processes. Common PTMs include phosphorylation, acetylation, ubiquitination, glycosylation, SUMOylation, methylation, sulfation, and nitrosylation. Among these modifications, O-GlcNAcylation has been shown to play a critical role in cancer development and progression, especially in hepatocellular carcinoma (HCC). This review outlines the role of O-GlcNAcylation in the development and progression of HCC. Moreover, we delve into the underlying mechanisms of O-GlcNAcylation in HCC and highlight compounds that target O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA) to improve treatment outcomes. Understanding the role of O-GlcNAcylation in HCC will offer insights into potential therapeutic strategies targeting OGT and OGA, which could improve treatment for patients with HCC.

High expression of AlkB homolog 5 suppresses the progression of non-small cell lung cancer by facilitating ferroptosis through m6A demethylation of SLC7A11

OBJECTIVE

Non-small cell lung cancer (NSCLC) is a prevailing LC characterized by poor outcomes. AlkB homolog 5 (ALKBH5) functions as a tumor suppressor in several cancers. This study delved into the role of ALKBH5 in NSCLC development.

METHODS

TCGA database predicted ALKBH5 expression in NSCLC patients. ALKBH5 levels in NSCLC and human bronchial epithelial cells were determined. pcDNA3.1-ALKBH5/NC, pcDNA3.1-SLC7A11/NC, and ferrostatin-1 were used to explore the interactions among ALKBH5, SLC7A11, and ferroptosis. SLC7A11 mRNA and its protein levels were measured by RT-qPCR and Western blot. Cell viability, apoptosis, migration, and invasion were assessed by CCK-8, flow cytometry, and Transwell. Total N6-methyladenosine (m6A) quantification and its enrichment on SLC7A11 mRNA were determined, followed by the observation of Ki67, ALKBH5 and SLC7A11-positive cell numbers. Glutathione (GSH), lipid reactive oxygen species (lipid-ROS), malondialdehyde (MDA), and iron ion contents were determined. Animal experiments further analyzed the role of ALKBH5 in tumor development and glutathione peroxidase 4 (GPX4) expression.

RESULTS

Bioinformatics analysis revealed the lowly-expressed ALKBH5 in LC patients. ALKBH5 was downregulated in NSCLC cells and its upregulation repressed proliferation activity, invasion, and migration, and facilitated apoptosis. ALKBH5 upregulation decreased GSH, increased lipid-ROS, MDA, and iron ion contents, and downregulated SLC7A11 by reducing m6A modification. SLC7A11 upregulation partly annulled the effect of ALKBH5 overexpression on cell ferroptosis and malignant behaviors. In vivo assays elucidated the suppression of ALKBH5 upregulation on tumor development and GPX4 levels.

CONCLUSION

ALKBH5 upregulation downregulates SLC7A11 transcription by decreasing m6A modification, thus promoting NSCLC cell ferroptosis and ultimately repressing NSCLC progression.

Advancements in inhibitors of crucial enzymes in the cysteine biosynthetic pathway: Serine acetyltransferase and O-acetylserine sulfhydrylase

Infectious diseases have been jeopardized problem that threaten public health over a long period of time. The growing prevalence of drug-resistant pathogens and infectious cases have led to a decrease in the number of effective antibiotics, which highlights the urgent need for the development of new antibacterial agents. Serine acetyltransferase (SAT), also known as CysE in certain bacterial species, and O-acetylserine sulfhydrylase (OASS), also known as CysK in select bacteria, are indispensable enzymes within the cysteine biosynthesis pathway of various pathogenic microorganisms. These enzymes play a crucial role in the survival of these pathogens, making SAT and OASS promising targets for the development of novel anti-infective agents. In this comprehensive review, we present an introduction to the structure and function of SAT and OASS, along with an overview of existing inhibitors for SAT and OASS as potential antibacterial agents. Our primary focus is on elucidating the inhibitory activities, structure-activity relationships, and mechanisms of action of these inhibitors. Through this exploration, we aim to provide insights into promising strategies and prospects in the development of antibacterial agents that target these essential enzymes.

Oxidative Stress in Breast Cancer: A Biochemical Map of Reactive Oxygen Species Production

This review systematizes information about the metabolic features of breast cancer directly related to oxidative stress. It has been shown those redox changes occur at all levels and affect many regulatory systems in the human body. The features of the biochemical processes occurring in breast cancer are described, ranging from nonspecific, at first glance, and strictly biochemical to hormone-induced reactions, genetic and epigenetic regulation, which allows for a broader and deeper understanding of the principles of oncogenesis, as well as maintaining the viability of cancer cells in the mammary gland. Specific pathways of the activation of oxidative stress have been studied as a response to the overproduction of stress hormones and estrogens, and specific ways to reduce its negative impact have been described. The diversity of participants that trigger redox reactions from different sides is considered more fully: glycolytic activity in breast cancer, and the nature of consumption of amino acids and metals. The role of metals in oxidative stress is discussed in detail. They can act as both co-factors and direct participants in oxidative stress, since they are either a trigger mechanism for lipid peroxidation or capable of activating signaling pathways that affect tumorigenesis. Special attention has been paid to the genetic and epigenetic regulation of breast tumors. A complex cascade of mechanisms of epigenetic regulation is explained, which made it possible to reconsider the existing opinion about the triggers and pathways for launching the oncological process, the survival of cancer cells and their ability to localize.

Advances in Ferroptosis-Inducing Agents by Targeted Delivery System in Cancer Therapy

Currently, cancer remains one of the most significant threats to human health. Treatment of most cancers remains challenging, despite the implementation of diverse therapies in clinical practice. In recent years, research on the mechanism of ferroptosis has presented novel perspectives for cancer treatment. Ferroptosis is a regulated cell death process caused by lipid peroxidation of membrane unsaturated fatty acids catalyzed by iron ions. The rapid development of bio-nanotechnology has generated considerable interest in exploiting iron-induced cell death as a new therapeutic target against cancer. This article provides a comprehensive overview of recent advancements at the intersection of iron-induced cell death and bionanotechnology. In this respect, the mechanism of iron-induced cell death and its relation to cancer are summarized. Furthermore, the feasibility of a nano-drug delivery system based on iron-induced cell death for cancer treatment is introduced and analyzed. Secondly, strategies for inducing iron-induced cell death using nanodrug delivery technology are discussed, including promoting Fenton reactions, inhibiting glutathione peroxidase 4, reducing low glutathione levels, and inhibiting system Xc-. Additionally, the article explores the potential of combined treatment strategies involving iron-induced cell death and bionanotechnology. Finally, the application prospects and challenges of iron-induced nanoagents for cancer treatment are discussed.

Ascorbic acid induces ferroptosis via STAT3/GPX4 signaling in oropharyngeal cancer

Ferroptosis is recognized as a new type of regulated cell death initiated by iron-dependent accumulation of lipid peroxidation. Recent studies have shown that the administration of ascorbic acid (AA) preferentially kills tumor cells by impairing iron metabolism and exerting pro-oxidant effects. Despite mounting evidence indicating the anticancer potential of AA, the underlying molecular mechanisms remain unknown. In this study, we demonstrated that AA decreased cell viability and Ki67 expression, along with its accumulation in the G0/G1 phase in FaDu and SCC-154 cell lines. Furthermore, AA exposure induced morphological changes in mitochondria associated with ferroptosis. AA-induced ferroptosis is accompanied by depletion of glutathione (GSH) and increased levels of ferrous ions (Fe2+), reactive oxygen species (ROS), and malondialdehyde (MDA). However, these ferroptotic effects were ameliorated by deferoxamine and N-acetylcysteine. Network pharmacology results showed that signal transducer and activator of transcription 3 (STAT3) is a key target of AA against oropharyngeal cancer. AA markedly downregulates the relative mRNA expression of STAT3 and glutathione peroxidase 4 (GPX4). Immunoblotting indicated that the protein levels of p-STAT3, STAT3, and GPX4 in FaDu and SCC-154 cells decreased significantly in response to AA treatment. Mechanistically, a chromatin immunoprecipitation assay confirmed that AA exposure reduced STAT3 expression in the GPX4 promoter region. Additionally, AA-induced inhibition of cell growth and ferroptosis was suppressed by STAT3 and GPX4 overexpression, respectively. In summary, AA inhibited oropharyngeal cancer cell growth in vitro by regulating STAT3/GPX4-mediated ferroptosis, which may provide a novel theoretical basis for the clinical treatment of oropharyngeal cancer with AA.

Cucurbitacin B and erastin co-treatment synergistically induced ferroptosis in breast cancer cells via altered iron-regulating proteins and lipid peroxidation

Ferroptosis is a unique type of cell death which co-exists with elevated iron, suppressed antioxidative function and increased lipid peroxidation. Recent studies have shown that cancer cells are particularly susceptible to the compounds with ferroptotic activities. Cucurbitacin B (CuB) is a triterpenoid with potent biological properties. It has been demonstrated to induce apoptosis and inhibit metastasis in cancer cells. However, the underlying mechanism of the compound is still not fully understood. In the present study, we investigated the ferroptotic effect of CuB in breast cancer cells and evaluated the impact of its combination with erastin, a ferroptosis inducer. In this regard, MTT assay was performed to analyze cell viability. Lipid peroxidation, oxidative stress and the cellular antioxidant capacity were determined with relevant kits. The expression of ferroptotic proteins were analyzed by western blotting. The results indicated that the combined treatment of CuB and erastin activated the ferroptotic pathways significantly in MCF-7 and MDA-MB-231 breast cancer cells. More importantly, the combination treatment altered the expression of iron-related proteins IREB2 and FPN1. In conclusion, this study demonstrated the ferroptotic potential of CuB in breast cancer cells for the first time, and revealed its impact on the expression of iron-regulating proteins.

Role of SLC7A11/xCT in Ovarian Cancer

Ovarian cancer is one of the most dangerous gynecologic cancers worldwide and has a high fatality rate due to diagnosis at an advanced stage of the disease as well as a high recurrence rate due to the occurrence of chemotherapy resistance. In fact, chemoresistance weakens the therapeutic effects, worsening the outcome of this pathology. Solute Carrier Family 7 Member 11 (SLC7A11, also known as xCT) is the functional subunit of the Xc- system, an anionic L-cystine/L-glutamate antiporter expressed on the cell surface. SLC7A11 expression is significantly upregulated in several types of cancers in which it can inhibit ferroptosis and favor cancer cell proliferation, invasion and chemoresistance. SLC7A11 expression is also increased in ovarian cancer tissues, suggesting a possible role of this protein as a therapeutic target. In this review, we provide an overview of the current literature regarding the role of SLC7A11 in ovarian cancer to provide new insights on SLC7A11 modulation and evaluate the potential role of SLC7A11 as a therapeutic target.

Targeting ferroptosis in gastric cancer: Strategies and opportunities

Ferroptosis is a novel form of programmed cell death morphologically, genetically, and biochemically distinct from other cell death pathways and characterized by the accumulation of iron-dependent lipid peroxides and oxidative damage. It is now understood that ferroptosis plays an essential role in various biological processes, especially in the metabolism of iron, lipids, and amino acids. Gastric cancer (GC) is a prevalent malignant tumor worldwide with low early diagnosis rates and high metastasis rates, accounting for its relatively poor prognosis. Although chemotherapy is commonly used to treat GC, drug resistance often leads to poor therapeutic outcomes. In the last several years, extensive research on ferroptosis has highlighted its significant potential in GC therapy, providing a promising strategy to address drug resistance associated with standard cancer therapies. In this review, we offer an extensive summary of the key regulatory factors related to the mechanisms underlying ferroptosis. Various inducers and inhibitors specifically targeting ferroptosis are uncovered. Additionally, we explore the prospective applications and outcomes of these agents in the field of GC therapy, emphasizing their capacity to improve the outcomes of this patient population.

Ferroptosis landscape in prostate cancer from molecular and metabolic perspective

Prostate cancer is a major disease that threatens men's health. Its rapid progression, easy metastasis, and late castration resistance have brought obstacles to treatment. It is necessary to find new effective anticancer methods. Ferroptosis is a novel iron-dependent programmed cell death that plays a role in various cancers. Understanding how ferroptosis is regulated in prostate cancer will help us to use it as a new way to kill cancer cells. In this review, we summarize the regulation and role of ferroptosis in prostate cancer and the relationship with AR from the perspective of metabolism and molecular pathways. We also discuss the feasibility of ferroptosis in prostate cancer treatment and describe current limitations and prospects, providing a reference for future research and clinical application of ferroptosis.

Etoposide in combination with erastin synergistically altered iron homeostasis and induced ferroptotic cell death through regulating IREB2/FPN1 expression in estrogen receptor positive-breast cancer cells

AIM

Ferroptosis is an iron-dependent cell death mechanism that substantially differs from apoptosis. Since its mechanism involves increased oxidative stress and rich iron content, cancer cells are particularly vulnerable to ferroptotic death compared to healthy tissues. In the present study, the effect of etoposide in combination with a ferroptotic agent, erastin, was investigated in breast cancer.

MAIN METHODS

Cell viability was assessed by the MTT assay. Oxidative stress, lipid peroxidation and glutathione peroxidase activity were detected using the relevant kits. Intracellular iron levels were measured by HPLC. Ferroptosis markers were explored by western blotting.

KEY FINDINGS

Results demonstrated that although etoposide didn't induce a significant cell death up to 50 μM in MCF-7 cells, with the addition of erastin, a significant synergistic activity was achieved at a dose as low as 1 μM (p < 0.05), contrary to normal breast epithelial cells. This cytotoxic effect was blocked by ferrostatin-1, which is a specific inhibitor of ferroptosis. The combined treatment of etoposide and erastin synergistically induced oxidative stress and lipid peroxidation, while suppressing glutathione peroxidase activity. More importantly, the combination treatment synergistically increased iron accumulation, which was associated with altered expression of IREB2/FPN1. Additionally, ferroptosis-regulating proteins ACSF2 and GPX4 were altered more potently by the combination treatment, compared to untreated cells and erastin treatment alone (p < 0.05).

SIGNIFICANCE

In conclusion, this is the first study that reports enhanced cytotoxicity of etoposide, in combination with erastin, in ER-positive breast cancer cells via activation of ferroptotic pathways, and offers a new perspective for future regimens.

The role of microRNAs in ferroptosis

Ferroptosis is a newly discovered type of programmed cell death, which is closely related to the imbalance of iron metabolism and oxidative stress. Ferroptosis has become an important research topic in the fields of cardiomyopathy, tumors, neuronal injury disorders, and ischemia perfusion disorders. As an important part of non-coding RNA, microRNAs regulate various metabolic pathways in the human body at the post-transcriptional level and play a crucial role in the occurrence and development of many diseases. The present review introduces the mechanisms of ferroptosis and describes the relevant pathways by which microRNAs affect cardiomyopathy, tumors, neuronal injury disorders and ischemia perfusion disorders through regulating ferroptosis. In addition, it provides important insights into ferroptosis-related microRNAs, aiming to uncover new methods for treatment of the above diseases, and discusses new ideas for the implementation of possible microRNA-based ferroptosis-targeted therapies in the future.

The amino acid transporter SLC7A11-mediated crosstalk implicated in cancer therapy and the tumor microenvironment

The solute carrier family 7 member 11 (SLC7A11), an amino acid transporter protein is frequently overexpressed in human malignancies. The expression and activity of SLC7A11 is finely regulated by oncogenes and tumor suppressors in tumor cells through various mechanisms and is highly specific for cystine and glutamate. Cystine is mainly transported intracellularly by SLC7A11 in the tumor microenvironment (TME) and is involved in GSH synthesis, which leads to ferroptosis resistance in tumor cells and promotes tumorigenesis and progression. The downregulation of SLC7A11 presents a unique drug discovery opportunity for ferroptosis-related diseases. Experimental work has shown that the combination of targeting SLC7A11 and tumor immunotherapy triggers ferroptosis more potently. Moreover, immunotargeting of SLC7A11 increases the chemosensitivity of cancer stem cells to doxorubicin, suggesting that it may act as an adjuvant to chemotherapy. Thus, SLC7A11 could be a promising target to overcome resistance mechanisms in conventional cancer treatments. This review provides an overview of the regulatory network of SLC7A11 in the TME and progress in the development of SLC7A11 inhibitors. In addition, we summarize the cytotoxic effects of blocking SLC7A11 in cancer cells, cancer stem cells and immune cells.

Bromodomains in Human-Immunodeficiency Virus-Associated Neurocognitive Disorders: A Model of Ferroptosis-Induced Neurodegeneration

Human immunodeficiency virus (HIV)-associated neurocognitive disorders (HAND) comprise a group of illnesses marked by memory and behavioral dysfunction that can occur in up to 50% of HIV patients despite adequate treatment with combination antiretroviral drugs. Iron dyshomeostasis exacerbates HIV-1 infection and plays a major role in Alzheimer's disease pathogenesis. In addition, persons living with HIV demonstrate a high prevalence of neurodegenerative disorders, indicating that HAND provides a unique opportunity to study ferroptosis in these conditions. Both HIV and combination antiretroviral drugs increase the risk of ferroptosis by augmenting ferritin autophagy at the lysosomal level. As many viruses and their proteins exit host cells through lysosomal exocytosis, ferroptosis-driving molecules, iron, cathepsin B and calcium may be released from these organelles. Neurons and glial cells are highly susceptible to ferroptosis and neurodegeneration that engenders white and gray matter damage. Moreover, iron-activated microglia can engage in the aberrant elimination of viable neurons and synapses, further contributing to ferroptosis-induced neurodegeneration. In this mini review, we take a closer look at the role of iron in the pathogenesis of HAND and neurodegenerative disorders. In addition, we describe an epigenetic compensatory system, comprised of bromodomain-containing protein 4 (BRD4) and microRNA-29, that may counteract ferroptosis by activating cystine/glutamate antiporter, while lowering ferritin autophagy and iron regulatory protein-2. We also discuss potential interventions for lysosomal fitness, including ferroptosis blockers, lysosomal acidification, and cathepsin B inhibitors to achieve desirable therapeutic effects of ferroptosis-induced neurodegeneration.

IFNγ enhances ferroptosis by increasing JAK‑STAT pathway activation to suppress SLCA711 expression in adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is a rare type of tumor with a poor prognosis. Ferroptosis is a relatively novel form of programmed cell death driven by iron-dependent lipid peroxidation accumulation. Recent evidence suggests that IFNγ facilitates erastin-induced ferroptosis, which contributed to anticancer therapy in various types of cancer. However, it has remained elusive whether the regulation of IFNγ on ferroptosis has a positive role in the treatment of ACC. Thus, the aim of the present study was to explore the effects of IFNγ on erastin-induced ferroptosis in the ACC cell line NCI-H295R and investigate the underlying mechanisms. Cell viability was assessed using a Cell Counting Kit-8 assay, an ethynyldioxyuridine proliferation assay and Live/Dead staining. The levels of iron, reactive oxygen species, lipid peroxidation and mitochondrial damage were also assessed. Western blot and reverse transcription-quantitative PCR analyses were used to determine the underlying molecular mechanisms involved in the erastin-induced ferroptosis of NCI-H295R cells. The results suggested that IFNγ promoted erastin-induced ferroptotic cell death. Furthermore, IFNγ enhanced erastin-induced ferroptosis, as evidenced by the accumulation of iron, as well as the increase in lipid peroxidation and promotion of mitochondrial damage. Further analysis suggested that IFNγ enhanced ferroptosis by suppressing the expression of solute carrier family 7 member 11, an important negative regulator of ferroptosis, and this was achieved via activation of the JAK/STAT pathway in NCI-H295R cells. The present study provided experimental evidence on the activity and mechanism of ferroptosis enhanced by IFNγ in ACC and may give critical insight into the immunotherapeutic management of ACC.