-
Protein & Cell Aug 2021The cystine/glutamate antiporter SLC7A11 (also commonly known as xCT) functions to import cystine for glutathione biosynthesis and antioxidant defense and is... (Review)
Review
The cystine/glutamate antiporter SLC7A11 (also commonly known as xCT) functions to import cystine for glutathione biosynthesis and antioxidant defense and is overexpressed in multiple human cancers. Recent studies revealed that SLC7A11 overexpression promotes tumor growth partly through suppressing ferroptosis, a form of regulated cell death induced by excessive lipid peroxidation. However, cancer cells with high expression of SLC7A11 (SLC7A11) also have to endure the significant cost associated with SLC7A11-mediated metabolic reprogramming, leading to glucose- and glutamine-dependency in SLC7A11 cancer cells, which presents potential metabolic vulnerabilities for therapeutic targeting in SLC7A11 cancer. In this review, we summarize diverse regulatory mechanisms of SLC7A11 in cancer, discuss ferroptosis-dependent and -independent functions of SLC7A11 in promoting tumor development, explore the mechanistic basis of SLC7A11-induced nutrient dependency in cancer cells, and conceptualize therapeutic strategies to target SLC7A11 in cancer treatment. This review will provide the foundation for further understanding SLC7A11 in ferroptosis, nutrient dependency, and tumor biology and for developing novel effective cancer therapies.
Topics: Amino Acid Transport System y+; Antineoplastic Agents; Cystine; DNA Methylation; Ferroptosis; Gene Expression Regulation, Neoplastic; Glucose; Glutamine; Glutathione; Histones; Humans; Molecular Targeted Therapy; Neoplasms; Piperazines; Signal Transduction; Sorafenib; Sulfasalazine
PubMed: 33000412
DOI: 10.1007/s13238-020-00789-5 -
Frontiers in Immunology 2022Ferroptosis is a kind of regulatory cell death (RCD) caused by iron accumulation and lipid peroxidation, which is characterized by mitochondrial morphological changes... (Review)
Review
Ferroptosis is a kind of regulatory cell death (RCD) caused by iron accumulation and lipid peroxidation, which is characterized by mitochondrial morphological changes and has a complex regulatory network. Ferroptosis has been gradually emphasized in the pathogenesis of inflammatory arthritis. In this review, we summarized the relevant research on ferroptosis in various inflammatory arthritis including rheumatoid arthritis (RA), osteoarthritis, gout arthritis, and ankylosing spondylitis, and focused on the relationship between RA and ferroptosis. In patients with RA and animal models of RA, there was evidence of iron overload and lipid peroxidation, as well as mitochondrial dysfunction that may be associated with ferroptosis. Ferroptosis inducers have shown good application prospects in tumor therapy, and some anti-rheumatic drugs such as methotrexate and sulfasalazine have been shown to have ferroptosis modulating effects. These phenomena suggest that the role of ferroptosis in the pathogenesis of inflammatory arthritis will be worth further study. The development of therapeutic strategies targeting ferroptosis for patients with inflammatory arthritis may be a promising future.
Topics: Animals; Arthritis, Rheumatoid; Ferroptosis; Iron; Iron Overload; Lipid Peroxidation
PubMed: 35958605
DOI: 10.3389/fimmu.2022.955069 -
International Journal of Molecular... Jul 2020Ferroptosis is an iron-dependent form of cell death characterized by intracellular lipid peroxide accumulation and redox imbalance. Ferroptosis shows specific biological... (Review)
Review
Ferroptosis is an iron-dependent form of cell death characterized by intracellular lipid peroxide accumulation and redox imbalance. Ferroptosis shows specific biological and morphological features when compared to the other cell death patterns. The loss of lipid peroxide repair activity by glutathione peroxidase 4 (GPX4), the presence of redox-active iron and the oxidation of polyunsaturated fatty acid (PUFA)-containing phospholipids are considered as distinct fingerprints of ferroptosis. Several pathways, including amino acid and iron metabolism, ferritinophagy, cell adhesion, p53, Keap1/Nrf2 and phospholipid biosynthesis, can modify susceptibility to ferroptosis. Through the decades, various diseases, including acute kidney injury; cancer; ischemia-reperfusion injury; and cardiovascular, neurodegenerative and hepatic disorders, have been associated with ferroptosis. In this review, we provide a comprehensive analysis of the main biological and biochemical mechanisms of ferroptosis and an overview of chemicals used as inducers and inhibitors. Then, we report the contribution of ferroptosis to the spectrum of liver diseases, acute or chronic. Finally, we discuss the use of ferroptosis as a therapeutic approach against hepatocellular carcinoma, the most common form of primary liver cancer.
Topics: Animals; Autophagy; Chemical and Drug Induced Liver Injury; Cyclohexylamines; Cysteine; Ferroptosis; Glutathione; Heme; Humans; Iron; Kelch-Like ECH-Associated Protein 1; Lipid Peroxidation; Lipoxygenase; Liver Diseases; Liver Neoplasms; Oxidative Stress; Phenylenediamines; Phospholipid Hydroperoxide Glutathione Peroxidase; Piperazines; Quinoxalines; Reactive Oxygen Species; Reperfusion Injury; Signal Transduction; Sorafenib; Spiro Compounds; Sulfasalazine; Tumor Suppressor Protein p53; alpha-Tocopherol
PubMed: 32664576
DOI: 10.3390/ijms21144908 -
Current Gastroenterology Reports Mar 2023Crohn's Disease (CD) is a chronic inflammatory disease that can lead to progressive damage to the gastrointestinal tract and significant disability. Early, "top-down"... (Review)
Review
PURPOSE OF REVIEW
Crohn's Disease (CD) is a chronic inflammatory disease that can lead to progressive damage to the gastrointestinal tract and significant disability. Early, "top-down" biologic therapy is recommended in moderate-to-severe CD to induce remission and to prevent hospitalization and complications. However, an estimated 20-30% of patients with CD have a mild disease course and may not garner sufficient benefit from expensive, immunosuppressing agents to justify their risks. Herein, we review characteristics of patients with mild CD, the available options for disease treatment and monitoring, and future directions of research.
RECENT FINDINGS
For ambulatory outpatients with low-risk, mild, ileal or ileocolonic CD, induction of remission with budesonide is recommended. For colonic CD, sulfasalazine is a reasonable choice, although other aminosalicylates have no role in the treatment of CD. No large, randomized trial has supported the use of antibiotics or antimycobacterials in the treatment of CD. Partial Enteral Nutrition and Crohn's Disease Exclusion Diets may be appropriate for inducing remission in some adult patients, with trials ongoing. Select patients with mild-to-moderate CD may benefit from maintenance therapy with azathioprines or gut specific biologics, such as vedolizumab. The role of complementary and alternative medicine is not well defined. The identification, risk stratification, and monitoring of patients with mild CD can be a challenging clinical scenario. Some patients with low risk of disease progression may be appropriate for initial induction of remission with budesonide or sulfasalazine, followed by close clinical monitoring. Future research should focus on pre-clinical biomarkers to stratify disease, novel therapies with minimal systemic immune suppression, and validation of rigorous clinical monitoring algorithms.
Topics: Humans; Crohn Disease; Sulfasalazine; Budesonide; Anti-Bacterial Agents; Enteral Nutrition; Remission Induction
PubMed: 36753033
DOI: 10.1007/s11894-023-00863-y -
Clinical Rheumatology Sep 2023Systematic r eview to evaluate the quality of the clinical practice guidelines (CPG) for rheumatoid arthritis (RA) management and to provide a synthesis of high-quality... (Review)
Review
Systematic r eview to evaluate the quality of the clinical practice guidelines (CPG) for rheumatoid arthritis (RA) management and to provide a synthesis of high-quality CPG recommendations, highlighting areas of consistency, and inconsistency. Electronic searches of five databases and four online guideline repositories were performed. RA management CPGs were eligible for inclusion if they were written in English and published between January 2015 and February 2022; focused on adults ≥ 18 years of age; met the criteria of a CPG as defined by the Institute of Medicine; and were rated as high quality on the Appraisal of Guidelines for Research and Evaluation II instrument. RA CPGs were excluded if they required additional payment to access; only addressed recommendations for the system/organization of care and did not include interventional management recommendations; and/or included other arthritic conditions. Of 27 CPGs identified, 13 CPGs met eligibility criteria and were included. Non-pharmacological care should include patient education, patient-centered care, shared decision-making, exercise, orthoses, and a multi-disciplinary approach to care. Pharmacological care should include conventional synthetic disease modifying anti-rheumatic drugs (DMARDs), with methotrexate as the first-line choice. If monotherapy conventional synthetic DMARDs fail to achieve a treatment target, this should be followed by combination therapy conventional synthetic DMARDs (leflunomide, sulfasalazine, hydroxychloroquine), biologic DMARDS and targeted synthetic DMARDS. Management should also include monitoring, pre-treatment investigations and vaccinations, and screening for tuberculosis and hepatitis. Surgical care should be recommended if non-surgical care fails. This synthesis offers clear guidance of evidence-based RA care to healthcare providers. TRIAL REGISTRATION: The protocol for this review was registered with Open Science Framework ( https://doi.org/10.17605/OSF.IO/UB3Y7 ).
Topics: Adult; Humans; Antirheumatic Agents; Arthritis, Rheumatoid; Hydroxychloroquine; Methotrexate; Sulfasalazine; Practice Guidelines as Topic
PubMed: 37291382
DOI: 10.1007/s10067-023-06654-0 -
Cancer Discovery Dec 2019A challenge in oncology is to rationally and effectively integrate immunotherapy with traditional modalities, including radiotherapy. Here, we demonstrate that...
A challenge in oncology is to rationally and effectively integrate immunotherapy with traditional modalities, including radiotherapy. Here, we demonstrate that radiotherapy induces tumor-cell ferroptosis. Ferroptosis agonists augment and ferroptosis antagonists limit radiotherapy efficacy in tumor models. Immunotherapy sensitizes tumors to radiotherapy by promoting tumor-cell ferroptosis. Mechanistically, IFNγ derived from immunotherapy-activated CD8 T cells and radiotherapy-activated ATM independently, yet synergistically, suppresses SLC7A11, a unit of the glutamate-cystine antiporter xc, resulting in reduced cystine uptake, enhanced tumor lipid oxidation and ferroptosis, and improved tumor control. Thus, ferroptosis is an unappreciated mechanism and focus for the development of effective combinatorial cancer therapy. SIGNIFICANCE: This article describes ferroptosis as a previously unappreciated mechanism of action for radiotherapy. Further, it shows that ferroptosis is a novel point of synergy between immunotherapy and radiotherapy. Finally, it nominates SLC7A11, a critical regulator of ferroptosis, as a mechanistic determinant of synergy between radiotherapy and immunotherapy..
Topics: Amino Acid Transport System y+; Animals; Antineoplastic Agents, Immunological; CD8-Positive T-Lymphocytes; Cell Line, Tumor; Cell Survival; Down-Regulation; Ferroptosis; Gene Expression Regulation, Neoplastic; Humans; Immunotherapy; Interferon-gamma; Lipid Metabolism; Melanoma, Experimental; Mice; Oxidation-Reduction; Sulfasalazine; Xenograft Model Antitumor Assays
PubMed: 31554642
DOI: 10.1158/2159-8290.CD-19-0338 -
Nature Cell Biology Apr 2020SLC7A11-mediated cystine uptake is critical for maintaining redox balance and cell survival. Here we show that this comes at a significant cost for cancer cells with...
SLC7A11-mediated cystine uptake is critical for maintaining redox balance and cell survival. Here we show that this comes at a significant cost for cancer cells with high levels of SLC7A11. Actively importing cystine is potentially toxic due to its low solubility, forcing cancer cells with high levels of SLC7A11 (SLC7A11) to constitutively reduce cystine to the more soluble cysteine. This presents a significant drain on the cellular NADPH pool and renders such cells dependent on the pentose phosphate pathway. Limiting glucose supply to SLC7A11 cancer cells results in marked accumulation of intracellular cystine, redox system collapse and rapid cell death, which can be rescued by treatments that prevent disulfide accumulation. We further show that inhibitors of glucose transporters selectively kill SLC7A11 cancer cells and suppress SLC7A11 tumour growth. Our results identify a coupling between SLC7A11-associated cystine metabolism and the pentose phosphate pathway, and uncover an accompanying metabolic vulnerability for therapeutic targeting in SLC7A11 cancers.
Topics: Amino Acid Transport System y+; Animals; Biological Transport; Carcinoma, Renal Cell; Cell Death; Cell Line, Tumor; Cystine; Disulfides; Gastrointestinal Agents; Gene Expression Regulation, Neoplastic; Glucose; Glucose Transporter Type 1; Glucose Transporter Type 3; Glucosephosphate Dehydrogenase; Humans; Kidney Neoplasms; Mice; Mice, Nude; Pentose Phosphate Pathway; Phosphogluconate Dehydrogenase; Pyrazoles; Quinolines; Stress, Physiological; Sulfasalazine; Survival Analysis; Xenograft Model Antitumor Assays
PubMed: 32231310
DOI: 10.1038/s41556-020-0496-x -
Digestion 2023Two major types of 5-aminosalicylic acid (5-ASA)-containing preparations, namely, mesalazine/5-ASA and sulfasalazine (SASP), are currently used as first-line therapy for... (Review)
Review
BACKGROUND
Two major types of 5-aminosalicylic acid (5-ASA)-containing preparations, namely, mesalazine/5-ASA and sulfasalazine (SASP), are currently used as first-line therapy for ulcerative colitis. Recent reports show that optimization of 5-ASA therapy is beneficial for both patient outcomes and healthcare costs. Although 5-ASA and SASP have good efficacy and safety profiles, clinicians occasionally encounter patients who develop 5-ASA intolerance.
SUMMARY
The most common symptoms of acute 5-ASA intolerance syndrome are exacerbation of diarrhea, fever, and abdominal pain. Patients who discontinue 5-ASA therapy because of intolerance have a higher risk of adverse clinical outcomes, such as hospital admission, colectomy, need for advanced therapies, and loss of response to anti-tumor necrosis factor (TNF) biologics. When patients develop symptoms of 5-ASA intolerance, the clinician should consider changing the type of 5-ASA preparation. Recent genome-wide association studies and meta-analyses have shown that 5-ASA allergy is associated with certain single-nucleotide polymorphisms. Although there are no modalities or biomarkers for diagnosing 5-ASA intolerance, the drug-induced lymphocyte stimulation test can be used to assist in the diagnosis of acute 5-ASA intolerance syndrome with high specificity and low sensitivity. This review presents a general overview of 5-ASA and SASP in the treatment of inflammatory bowel disease and discusses the latest insights into 5-ASA intolerance.
KEY MESSAGES
5-ASA is used as first-line therapy for ulcerative colitis. Optimization of 5-ASA may be beneficial for patient outcomes and healthcare systems. Acute 5-ASA intolerance syndrome is characterized by diarrhea, fever, and abdominal pain. Periodic renal function monitoring is recommended for patients receiving 5-ASA.
Topics: Humans; Mesalamine; Colitis, Ulcerative; Anti-Inflammatory Agents, Non-Steroidal; Genome-Wide Association Study; Remission Induction; Administration, Oral; Sulfasalazine; Fever; Abdominal Pain
PubMed: 36366816
DOI: 10.1159/000527452 -
Theranostics 2022: Intracellular bacterial survival is a major factor causing chronic or recurrent infection, leading to the failure of both host defense and/or antibiotic treatment....
: Intracellular bacterial survival is a major factor causing chronic or recurrent infection, leading to the failure of both host defense and/or antibiotic treatment. However, the elimination of intracellular bacteria is challenging as they are protected from antibiotics and host immune attack. Recent studies have indicated that iron helps macrophages against intracellular bacteria, contradictory to traditional "nutritional immunity", in which iron is considered a key nutrient for bacterial survival in host cells. However, how iron facilitates intracellular bacterial death has not been fully clarified. In this study, we found that ferroptotic stress can help macrophages suppress intracellular bacteria by reversing the importation of ferrous iron into bacterial vacuoles via ferroportin and thereby inducing ferroptosis-like bacterial death. : A macrophage model of bacterial invasion was established to monitor dynamic changes in ferroptotic hallmarks, including ferrous iron and lipid peroxidation. Ferroptosis inducers and inhibitors were added to the model to evaluate the relationship between ferroptotic stress and intracellular bacterial survival. We then determined the spatiotemporal distributions of ferroportin, ferrous iron, and lipid peroxidation in macrophages and intracellular bacteria. A bacterial infection mouse model was established to evaluate the therapeutic effects of drugs that regulate ferroptotic stress. : Ferrous iron and lipid peroxidation increased sharply in the early stage of bacterial infection in the macrophages, then decreased to normal levels in the late stage of infection. The addition of ferroptosis inducers (ras-selective lethal small molecule 3, sulfasalazine, and acetaminophen) in macrophages promoted intracellular bacterial suppression. Further studies revealed that ferrous iron could be delivered to the intracellular bacterial compartment via inward ferroportin transportation, where ferrous iron induced ferroptosis-like death of bacteria. In addition, ferroptotic stress declined to normal levels in the late stage of infection by regulating iron-related pathways in the macrophages. Importantly, we found that enhancing ferroptotic stress with a ferroptosis inducer (sulfasalazine) successfully suppressed bacteria in the mouse infection models. : Our study suggests that the spatiotemporal response to ferroptosis stress is an efficient pathway for macrophage defense against bacterial invasion, and targeting ferroptosis may achieve therapeutic targets for infectious diseases challenged by intracellular pathogens.
Topics: Animals; Cell Death; Ferroptosis; Iron; Macrophages; Mice; Sulfasalazine
PubMed: 35265210
DOI: 10.7150/thno.66663