Decreased plasma beta-carotene levels in women with uterine cervical dysplasias and cancer

Adaptive Changes Allow Targeting of Ferroptosis for Glioma Treatment

Ferroptosis is a type of regulated cell death that plays an essential role in various brain diseases, including cranial trauma, neuronal diseases, and brain tumors. It has been reported that cancer cells rely on their robust antioxidant capacity to escape ferroptosis. Therefore, ferroptosis exploitation could be an effective strategy to prevent tumor proliferation and invasion. Glioma is a common malignant craniocerebral tumor exhibiting complicated drug resistance and survival mechanisms, resulting in a high mortality rate and short survival time. Recent studies have determined that metabolic alterations in glioma offer exploitable therapeutic targets. These metabolic alterations allow targeted therapy to achieve some initial efficacy but have failed to inhibit glioma growth, invasion, and drug resistance effectively. It has been proposed that the reason for the high malignancy and drug resistance observed with glioma is that these tumors can effectively evade ferroptosis. Ferroptosis-inducing drugs were found to exert a positive effect by targeting this particular characteristic of glioma cells. Moreover, gliomas develop enhanced drug resistance through anti-ferroptosis mechanisms. In this study, we provided an overview of the mechanisms by which glioma aggressiveness and drug resistance are mediated by the evasion of ferroptosis. This information might provide new targets for glioma therapy as well as new insights and ideas for future research.

AUF1 protects against ferroptosis to alleviate sepsis-induced acute lung injury by regulating NRF2 and ATF3

BACKGROUND

The AU-rich element (ARE)-binding factor 1 (AUF1) acts as a switch for septic shock, although its underlying mechanisms remain largely unknown. In this study, we examined the biological significance and potential molecular mechanism of AUF1 in regulating ferroptosis in sepsis-induced acute lung injury (ALI).

METHODS

Alveolar epithelial cells (AECs) challenged with ferroptosis-inducing compounds and cecum ligation and puncture (CLP)-induced ALI were used as the in vitro and in vivo model, respectively. The stability of AUF1 and its degradation by ubiquitin-proteasome pathway were examined by cycloheximide chase analysis and co-immunoprecipitation assay. The regulation of AUF1 on nuclear factor E2-related factor 2 (NRF2) and activation transcription factor 3 (ATF3) was explored by RNA immunoprecipitation (RIP), RNA pull-down, and mRNA stability assays. Functionally, the effects of altering AUF1, NRF2 or ATF3 on ferroptosis in AECs or ALI mice were evaluated by measuring cell viability, lipid peroxidation, iron accumulation, and total glutathione level.

RESULTS

AUF1 was down-regulated in AECs challenged with ferroptosis-inducing compounds, both on mRNA and protein levels. The E3 ubiquitin ligase FBXW7 was responsible for protein degradation of AUF1 during ferroptosis. By up-regulating NRF2 and down-regulating ATF3, AUF1 antagonized ferroptosis in AECs in vitro. In the CLP-induced ALI model, the survival rate of AUF1 knockout mice was significantly reduced and the lung injuries were aggravated, which were related to the enhancement of lung ferroptosis.

CONCLUSIONS

FBXW7 mediates the ubiquitination and degradation of AUF1 in ferroptosis. AUF1 antagonizes ferroptosis by regulating NRF2 and ATF3 oppositely. Activating AUF1 pathway may be beneficial to the treatment of sepsis-induced ALI.

The Gpx4NIKO Mouse Is a Versatile Model for Testing Interventions Targeting Ferroptotic Cell Death of Spinal Motor Neurons

The degeneration and death of motor neurons lead to motor neuron diseases such as amyotrophic lateral sclerosis (ALS). Although the exact mechanism by which motor neuron degeneration occurs is not well understood, emerging evidence implicates the involvement of ferroptosis, an iron-dependent oxidative mode of cell death. We reported previously that treating Gpx4NIKO mice with tamoxifen to ablate the ferroptosis regulator glutathione peroxidase 4 (GPX4) in neurons produces a severe paralytic model resembling an accelerated form of ALS that appears to be caused by ferroptotic cell death of spinal motor neurons. In this study, in support of the role of ferroptosis in this model, we found that the paralytic symptoms and spinal motor neuron death of Gpx4NIKO mice were attenuated by a chemical inhibitor of ferroptosis. In addition, we observed that the paralytic symptoms of Gpx4NIKO mice were malleable and could be tapered by lowering the dose of tamoxifen, allowing for the generation of a mild paralytic model without a rapid onset of death. We further used both models to evaluate mitochondrial reactive oxygen species (mtROS) in the ferroptosis of spinal motor neurons and showed that overexpression of peroxiredoxin 3, a mitochondrial antioxidant defense enzyme, ameliorated symptoms of the mild but not the severe model of the Gpx4NIKO mice. Our results thus indicate that the Gpx4NIKO mouse is a versatile model for testing interventions that target ferroptotic death of spinal motor neurons in vivo.

Novel insights into the SLC7A11-mediated ferroptosis signaling pathways in preeclampsia patients: identifying pannexin 1 and toll-like receptor 4 as innovative prospective diagnostic biomarkers

PURPOSE

Ferroptosis is associated with oxidative stress (OS) and is caused by iron-dependent lipid-peroxidative damage, but its role in PE is unclear. The aim of this study is to determine whether pannexin 1 (Panx1) and toll-like receptor 4 (TLR4) are key regulators of ferroptosis in PE.

METHODS

The study included 65 patients with PE and 25 healthy pregnant women. In normal and PE placental tissues, OS and ferroptosis markers, including Fe²⁺, malondialdehyde (MDA), reduced glutathione (GSH) levels, heme oxygenase-1 (HO-1) and glutathione peroxidase 4 (Gpx4) activity, were estimated. Panx1 and solute carrier family 7 member 11 (SLC7A11) mRNA expression levels were relatively quantified in placental tissues using real-time polymerase chain reaction (RT-PCR), while serum Panx1, serum TLR4, and placental activating transcription factor 3 (ATF3) levels were measured by ELISA.

RESULTS

In placental tissues, Panx1 and TLR4 expression levels were significantly increased in patients with PE compared to controls and were positively correlated with pro-ferroptosis mediators such as placental Fe²⁺ and MDA levels and negatively correlated with anti-ferroptosis regulators such as placental GSH level, HO-1, and Gpx4 activity. Additionally, Panx1 and TLR4 had a positive correlation with ATF3 and a negative correlation with SLC7A11. Serum Panx1 and TLR4 levels were positively correlated with their placental tissue expression and showed good diagnostic capabilities for ferroptosis in PE.

CONCLUSION

Therefore, Panx1 and TLR4 are suggested to induce ferroptosis in PE via SLC7A11-mediated signaling pathways, offering a novel perspective on PE pathogenesis and novel diagnostic tools for PE.

Comprehensive analysis of the autophagy-dependent ferroptosis-related gene FANCD2 in lung adenocarcinoma

BACKGROUND

The development of lung adenocarcinoma (LUAD) involves the interactions between cell proliferation and death. Autophagy-dependent ferroptosis, a distinctive cell death process, was implicated in a multitude of diseases, whereas no research revealing the relationship between autophagy-dependent ferroptosis and LUAD pathogenesis was reported. Thus, the primary objective was to explore the role and potential function of the autophagy-dependent ferroptosis-related genes in LUAD.

METHODS

Clinical information and transcriptome profiling of patients with LUAD were retrieved and downloaded from open-source databases. Autophagy-dependent ferroptosis-related genes were screened by published articles. The critical gene was identified as the intersection between the differentially expressed genes and prognosis-related genes. Patients were divided into high- and low-risk groups using the expression level of the critical gene. The validity of the key gene prognosis model was verified by survival analysis. The correlation between the clinical characteristics of LUAD and the expression level of the key gene was analyzed to explore the clinical significance and prognosis value. And the roles of the key gene in response to chemotherapy, immune microenvironment, and tumor mutation burden were predicted. The validation of key gene expression levels was further performed by quantitative real-time PCR and immunohistochemistry staining.

RESULTS

FANCD2, an essential autophagy-dependent ferroptosis-related gene by searching database, was confirmed as an independent prognostic factor for LUAD occurrence. The high expression level of FANCD2 was associated with an advantaged TNM stage, a less chemotherapy sensitivity, a low ImmuneScore, which indicated a deactivation status in an immune microenvironment, a high tumor mutation burden, and poor survival for LUAD patients. Pathway enrichment analysis showed that FANCD2 responded to oxidative stress and neutrophil-mediated immunity. Quantitative real-time PCR and immunohistochemistry staining showed that the expression level of FANCD2 is higher in LUAD patients than in normal tissue samples, which was in accordance with the database report.

CONCLUSION

FANCD2, an essential gene related to autophagy-dependent ferroptosis, could work as a biomarker, predicting the survival, chemotherapy sensitivity, tumor immunity, and mutation burden of LUAD. Researching autophagy-dependent ferroptosis and targeting the FANCD2 may offer a new perspective for treating and improving prognosis in LUAD.

Combination of ferroptosis and pyroptosis to construct a prognostic classifier and predict immune landscape, chemotherapeutic efficacy and immunosuppressive molecules in hepatocellular carcinoma

BACKGROUND

The induction of ferroptosis and pyroptosis has been highlighted as a novel approach to decide cancer cell fate. However, few studies have systematically explored the role of combining these two novel cell death modalities in hepatocellular carcinoma  (HCC).

METHODS

Ferroptosis-related genes (FRGs) and pyroptosis-related genes (PRGs) were retrieved and downloaded from FerrDb and GeneCards database, respectively. A prognostic classifier integrating with prognostic differentially expressed FRGs and PRGs was constructed by the least absolute shrinkage and selection operator (LASSO) algorithm in the TCGA-LIHC dataset and verified using the ICGC (LIRI-JP) dataset.

RESULTS

A total of 194 differentially expressed FRGs and PRGs were identified and named as differentially expressed genes (DEGs) and, out of them 79 were found dramatically correlated with prognosis in HCC. Based on 13 key DEGs with prognostic value, a novel expression signature was constructed and used to stratify HCC patients into 2 groups. Kaplan-Meier analysis demonstrated that high-risk patients had a more dismal prognosis. Receiver operating characteristic curve (ROC) and multivariate Cox analysis confirmed its predictive power and independent characteristic. Immune profile analysis demonstrated that high-risk group had prominent upregulation of immunosuppressive cells, including macrophages, Th2_cells and Treg. The correlation analysis between this signature and immunosuppressive molecules, Immunophenoscore (IPS) and chemotherapeutic efficacy demonstrated that low-risk group had a higher  IC50 of cisplatin, mitomycin and doxorubicin and negatively related with CTLA4, HAVCR2, LAG3, PDCD1, TIGIT and ICIs treatment represented by CTLA4-/PD-1-, CTLA4 + /PD-1-, CTLA4-/PD-1 + .

CONCLUSIONS

In this research, a novel expression signature was identified based on FRGs and PRGs in HCC, and this signature could be used to predict prognosis and select patients potentially benefiting from immunotherapies and chemotherapy.

MS4A15 drives ferroptosis resistance through calcium-restricted lipid remodeling

Ferroptosis is an iron-dependent form of cell death driven by biochemical processes that promote oxidation within the lipid compartment. Calcium (Ca²⁺) is a signaling molecule in diverse cellular processes such as migration, neurotransmission, and cell death. Here, we uncover a crucial link between ferroptosis and Ca²⁺ through the identification of the novel tetraspanin MS4A15. MS4A15 localizes to the endoplasmic reticulum, where it blocks ferroptosis by depleting luminal Ca²⁺ stores and reprogramming membrane phospholipids to ferroptosis-resistant species. Specifically, prolonged Ca²⁺ depletion inhibits lipid elongation and desaturation, driving lipid droplet dispersion and formation of shorter, more saturated ether lipids that protect phospholipids from ferroptotic reactive species. We further demonstrate that increasing luminal Ca²⁺ levels can preferentially sensitize refractory cancer cell lines. In summary, MS4A15 regulation of anti-ferroptotic lipid reservoirs provides a key resistance mechanism that is distinct from antioxidant and lipid detoxification pathways. Manipulating Ca²⁺ homeostasis offers a compelling strategy to balance cellular lipids and cell survival in ferroptosis-associated diseases.

Dexmedetomidine post-conditioning alleviates myocardial ischemia-reperfusion injury in rats by ferroptosis inhibition via SLC7A11/GPX4 axis activation

The SLC7A11/GPX4 axis plays an important role in ferroptosis during cardiac ischemia/reperfusion injury (IRI). The present study was designed to evaluate the impact of dexmedetomidine (DEX) post-conditioning on cardiac IRI and to explore whether the effect was achieved by SLC7A11/GPX4 signaling pathway regulation. Rat myocardial IRI was established by occluding the left anterior descending artery for 30 min followed by 2-h reperfusion. The infarct area was detected by diphenyltetrazolium chloride (TTC) staining; the cardiac function was evaluated by echocardiography. The levels of lipid peroxide biomarkers were measured to estimate the injury caused by lipid peroxide. HE staining and Sirius staining were utilized to assess myocardial damage and fibrosis. The mitochondrial morphology was observed by electron micrography. Western blot and quantitative real-time polymerase chain reaction were employed to measure the relative molecular characteristics. Our results showed that DEX administration at the beginning of reperfusion attenuated IRI-induced myocardial injury, alleviated mitochondrial dysfunction, decreased the level of reactive oxygen species (ROS), alleviated mitochondrial dysfunction, inhibited the activation of SLC7A11/GPX4, and modulated the expression of ferroptosis-related proteins, including SLC7A11, glutathione peroxidase 4 (GPX4), ferritin heavy chain (FTH), and cyclooxygenase-2 (COX-2). Conversely, the ferroptosis activator erastin partly suppressed the DEX-mediated cardio protection. Altogether, these results reveal that DEX inhibits ferroptosis by enhancing the expression of SLC7A11 and GPX4, thereby preventing cardiac I/R injury.

RIPK1 or RIPK3 deletion prevents progressive neuronal cell death and improves memory function after traumatic brain injury

Traumatic brain injury (TBI) causes acute and subacute tissue damage, but is also associated with chronic inflammation and progressive loss of brain tissue months and years after the initial event. The trigger and the subsequent molecular mechanisms causing chronic brain injury after TBI are not well understood. The aim of the current study was therefore to investigate the hypothesis that necroptosis, a form a programmed cell death mediated by the interaction of Receptor Interacting Protein Kinases (RIPK) 1 and 3, is involved in this process. Neuron-specific RIPK1- or RIPK3-deficient mice and their wild-type littermates were subjected to experimental TBI by controlled cortical impact. Posttraumatic brain damage and functional outcome were assessed longitudinally by repetitive magnetic resonance imaging (MRI) and behavioral tests (beam walk, Barnes maze, and tail suspension), respectively, for up to three months after injury. Thereafter, brains were investigated by immunohistochemistry for the necroptotic marker phosphorylated mixed lineage kinase like protein(pMLKL) and activation of astrocytes and microglia. WT mice showed progressive chronic brain damage in cortex and hippocampus and increased levels of pMLKL after TBI. Chronic brain damage occurred almost exclusively in areas with iron deposits and was significantly reduced in RIPK1- or RIPK3-deficient mice by up to 80%. Neuroprotection was accompanied by a reduction of astrocyte and microglia activation and improved memory function. The data of the current study suggest that progressive chronic brain damage and cognitive decline after TBI depend on the expression of RIPK1/3 in neurons. Hence, inhibition of necroptosis signaling may represent a novel therapeutic target for the prevention of chronic post-traumatic brain damage.

Effects of acute iron overload on Nrf2-related glutathione metabolism in rat brain

Iron (Fe) overload triggers free radical production and lipid peroxidation processes that may lead to cell death (ferroptosis). The hypothesis of this work was that acute Fe-dextran treatment triggers Nrf2-mediated antioxidant regulation in rat brain involving glutathione (GSH) metabolism. Over the initial 8 h after Fe-dextran administration (single dose of 500 mg Fe-dextran/kg), total Fe, malondialdehyde (MDA) content, glutathione peroxidase (GPx), GPx-Se dependent (GPx-Se) and glutathione S-transferases (GST) activities were increased in rat whole brain. The content of GSH and the activity of glutathione reductase (GR) showed decreases (p < 0.05) after 6 and 8 h post injection in cortex. A significant increase in nuclear Nrf2 protein levels over control values was achieved after 6 h of Fe-dextran administration, while no significant differences were observed in the cytosolic fraction. Nuclear Nrf2/cytosolic Nrf2 ratios showed enhancement (p < 0.05) after 6 h of Fe overload, suggesting a greater translocation of the factor to the nucleus. No significant differences were observed in the expression of Keap1 in nuclear or cytosolic extracts. It is concluded that acute Fe overload induces oxidative stress in rat brain with the concomitant lipid peroxidation increase and GSH depletion, leading to the elevation of Nrf2-controlled GPx, GPx-Se and GST protein expression as a protective adaptive response. Further studies are required to fully comprehend the complex network of interrelated processes keeping the balance of GSH functions as chelator, antioxidant and redox buffer in the understanding of the ferroptotic and hormetic mechanisms triggered by Fe overload in brain.

Ferroptosis, radiotherapy, and combination therapeutic strategies

Ferroptosis, an iron-dependent form of regulated cell death driven by peroxidative damages of polyunsaturated-fatty-acid-containing phospholipids in cellular membranes, has recently been revealed to play an important role in radiotherapy-induced cell death and tumor suppression, and to mediate the synergy between radiotherapy and immunotherapy. In this review, we summarize known as well as putative mechanisms underlying the crosstalk between radiotherapy and ferroptosis, discuss the interactions between ferroptosis and other forms of regulated cell death induced by radiotherapy, and explore combination therapeutic strategies targeting ferroptosis in radiotherapy and immunotherapy. This review will provide important frameworks for future investigations of ferroptosis in cancer therapy.

Ferroptosis: mechanisms, biology and role in disease

The research field of ferroptosis has seen exponential growth over the past few years, since the term was coined in 2012. This unique modality of cell death, driven by iron-dependent phospholipid peroxidation, is regulated by multiple cellular metabolic pathways, including redox homeostasis, iron handling, mitochondrial activity and metabolism of amino acids, lipids and sugars, in addition to various signalling pathways relevant to disease. Numerous organ injuries and degenerative pathologies are driven by ferroptosis. Intriguingly, therapy-resistant cancer cells, particularly those in the mesenchymal state and prone to metastasis, are exquisitely vulnerable to ferroptosis. As such, pharmacological modulation of ferroptosis, via both its induction and its inhibition, holds great potential for the treatment of drug-resistant cancers, ischaemic organ injuries and other degenerative diseases linked to extensive lipid peroxidation. In this Review, we provide a critical analysis of the current molecular mechanisms and regulatory networks of ferroptosis, the potential physiological functions of ferroptosis in tumour suppression and immune surveillance, and its pathological roles, together with a potential for therapeutic targeting. Importantly, as in all rapidly evolving research areas, challenges exist due to misconceptions and inappropriate experimental methods. This Review also aims to address these issues and to provide practical guidelines for enhancing reproducibility and reliability in studies of ferroptosis. Finally, we discuss important concepts and pressing questions that should be the focus of future ferroptosis research.

The deubiquitinase USP11 regulates cell proliferation and ferroptotic cell death via stabilization of NRF2 USP11 deubiquitinates and stabilizes NRF2

The transcription factor nuclear factor (erythroid-derived 2)-like 2 (NRF2) plays a key role in cancer progression and is tightly regulated by the proteasome pathway. E3 ligases that mediate NRF2 ubiquitination have been widely reported, but the mechanism of NRF2 deubiquitination remains largely unclear. Here, we identified ubiquitin-specific-processing protease 11 (USP11) in NRF2 complexes and confirmed an interaction between these two proteins. We further found that USP11 deubiquitinates NRF2; this modification stabilizes NRF2. Functionally, USP11 depletion contributes to the suppression of cell proliferation and induction of ferroptotic cell death due to ROS-mediated stress, which can be largely abrogated by overexpression of NRF2. Finally, immunohistochemical staining of USP11 and NRF2 was performed using a lung tissue microarray, which revealed that USP11 is highly expressed in patients with NSCLC and positively correlated with NRF2 expression. Together, USP11 stabilizes NRF2 and is thus an important player in cell proliferation and ferroptosis.

Heteromeric Amino Acid Transporters in Brain: from Physiology to Pathology

In humans, more than 50 transporters are responsible for the traffic and balance of amino acids within and between cells and tissues, and half of them have been associated with disease [1]. Covering all common amino acids, Heteromeric Amino acid Transporters (HATs) are one class of such transporters. This review first highlights structural and functional studies that solved the atomic structure of HATs and revealed molecular clues on substrate interaction. Moreover, this review focuses on HATs that have a role in the central nervous system (CNS) and that are related to neurological diseases, including: (i) LAT1/CD98hc and its role in the uptake of branched chain amino acids trough the blood brain barrier and autism. (ii) LAT2/CD98hc and its potential role in the transport of glutamine between plasma and cerebrospinal fluid. (iii) y⁺LAT2/CD98hc that is emerging as a key player in hepatic encephalopathy. xCT/CD98hc as a potential therapeutic target in glioblastoma, and (iv) Asc-1/CD98hc as a potential therapeutic target in pathologies with alterations in NMDA glutamate receptors.

ROS-Dependent Lipid Peroxidation and Reliant Antioxidant Ferroptosis-Suppressor-Protein 1 in Rheumatoid Arthritis: a Covert Clue for Potential Therapy

Rheumatoid arthritis (RA) is a common systemic autoimmune disease with a prevalence of about 1% in which genetic and environmental risk factors both participate in performance of disease. Though several studies contributed in identifying its etiology and pathogenesis, the underlying mechanisms are still unknown. To date, so as palliative for RA, cure strategies are still popular. Hypoxia and oxidative stress are implicated to RA development and subsequent ROS-mediated cell death which is a critical feature for RA progression. As for cell death and lipid peroxidation, ferroptosis is a newly discovered, iron-dependent, and non-apoptotic cell death which draws various attention due to its potential strategies for cancer therapy. Meanwhile, ferroptosis-suppressor-protein 1 (FSP1) is recently identified as a seminal breakthrough owing to its property of versus ferroptosis. By virtue of the complicated research progress on FSP1 with ferroptosis, in this review, we summarize the whole region of relevance between ROS and RA. Taken together, we hypothesize that ROS accompanied with ferroptosis may function as a reciprocal with cell death that interplays with RA; besides, FSP1 might become a potential therapeutic target for RA because of its potential interaction with TNF-α/ROS-positive feedback loop. This review systematically concludes the previous understandings about identification of ROS and FSP1 and, in turn, aims to provide references for further achievements of them and hints on elucidation of its thorough underlying mechanisms.

Broadening horizons: the role of ferroptosis in cancer

The discovery of regulated cell death processes has enabled advances in cancer treatment. In the past decade, ferroptosis, an iron-dependent form of regulated cell death driven by excessive lipid peroxidation, has been implicated in the development and therapeutic responses of various types of tumours. Experimental reagents (such as erastin and RSL3), approved drugs (for example, sorafenib, sulfasalazine, statins and artemisinin), ionizing radiation and cytokines (such as IFNγ and TGFβ1) can induce ferroptosis and suppress tumour growth. However, ferroptotic damage can trigger inflammation-associated immunosuppression in the tumour microenvironment, thus favouring tumour growth. The extent to which ferroptosis affects tumour biology is unclear, although several studies have found important correlations between mutations in cancer-relevant genes (for example, RAS and TP53), in genes encoding proteins involved in stress response pathways (such as NFE2L2 signalling, autophagy and hypoxia) and the epithelial-to-mesenchymal transition, and responses to treatments that activate ferroptosis. Herein, we present the key molecular mechanisms of ferroptosis, describe the crosstalk between ferroptosis and tumour-associated signalling pathways, and discuss the potential applications of ferroptosis in the context of systemic therapy, radiotherapy and immunotherapy.

Roles and mechanisms of BAP1 deubiquitinase in tumor suppression

The BAP1 gene has emerged as a major tumor suppressor mutated with various frequencies in numerous human malignancies, including uveal melanoma, malignant pleural mesothelioma, clear cell renal cell carcinoma, intrahepatic cholangiocarcinoma, hepatocellular carcinoma, and thymic epithelial tumors. BAP1 mutations are also observed at low frequency in other malignancies including breast, colorectal, pancreatic, and bladder cancers. BAP1 germline mutations are associated with high incidence of mesothelioma, uveal melanoma, and other cancers, defining the "BAP1 cancer syndrome." Interestingly, germline BAP1 mutations constitute an important paradigm for gene-environment interactions, as loss of BAP1 predisposes to carcinogen-induced tumorigenesis. Inactivating mutations of BAP1 are also identified in sporadic cancers, denoting the importance of this gene for normal tissue homeostasis and tumor suppression, although some oncogenic properties have also been attributed to BAP1. BAP1 belongs to the deubiquitinase superfamily of enzymes, which are responsible for the maturation and turnover of ubiquitin as well as the reversal of substrate ubiquitination, thus regulating ubiquitin signaling. BAP1 is predominantly nuclear and interacts with several chromatin-associated factors, assembling multi-protein complexes with mutually exclusive partners. BAP1 exerts its function through highly regulated deubiquitination of its substrates. As such, BAP1 orchestrates chromatin-associated processes including gene expression, DNA replication, and DNA repair. BAP1 also exerts cytoplasmic functions, notably in regulating Ca²⁺ signaling at the endoplasmic reticulum. This DUB is also subjected to multiple post-translational modifications, notably phosphorylation and ubiquitination, indicating that several signaling pathways tightly regulate its function. Recent progress indicated that BAP1 plays essential roles in multiple cellular processes including cell proliferation and differentiation, cell metabolism, as well as cell survival and death. In this review, we summarize the biological and molecular functions of BAP1 and explain how the inactivation of this DUB might cause human cancers. We also highlight some of the unresolved questions and suggest potential new directions.

Sulfur sequestration promotes multicellularity during nutrient limitation

The behaviour of Dictyostelium discoideum depends on nutrients¹. When sufficient food is present these amoebae exist in a unicellular state, but upon starvation they aggregate into a multicellular organism^2,3. This biology makes D. discoideum an ideal model for investigating how fundamental metabolism commands cell differentiation and function. Here we show that reactive oxygen species-generated as a consequence of nutrient limitation-lead to the sequestration of cysteine in the antioxidant glutathione. This sequestration limits the use of the sulfur atom of cysteine in processes that contribute to mitochondrial metabolism and cellular proliferation, such as protein translation and the activity of enzymes that contain an iron-sulfur cluster. The regulated sequestration of sulfur maintains D. discoideum in a nonproliferating state that paves the way for multicellular development. This mechanism of signalling through reactive oxygen species highlights oxygen and sulfur as simple signalling molecules that dictate cell fate in an early eukaryote, with implications for responses to nutrient fluctuations in multicellular eukaryotes.

Molecular characteristics associated with ferroptosis in hepatocellular carcinoma progression

The aim of this study was to investigate the genes associated with ferroptosis and the progression of hepatocellular carcinoma (HCC). The RNA sequencing data of erastin-induced ferroptosis in HCC cells were downloaded from the Sequence Read Archive database with accession number SRP119173. The microarray dataset GSE89377 of HCC progression was downloaded from the Gene Expression Omnibus database. The ferroptosis-related genes were screened by differential analysis and HCC progression-related genes were screened by cluster analysis using Mfuzz. Then, the genes associated with ferroptosis and HCC progression were screened by Venn analysis, followed by functional enrichment, protein-protein interaction (PPI) analysis, and transcription factor (TF) prediction. Finally, survival analysis was performed using data from the Cancer Genome Atlas database. A total of 33 upregulated and 52 downregulated genes associated with HCC progression and ferroptosis were obtained, and these genes were significantly involved in the negative regulation of ERK1 and ERK2 cascades; the NAD biosynthetic process; alanine, aspartate, and glutamate metabolism; and other pathways. The PPI network contained 52 genes and 78 interactions, of which, cell division cycle 20 (CDC20) and heat shock protein family B (small) member 1 (HSPB1) were hub genes found in higher degrees. Among the 85 genes associated with HCC progression and ferroptosis, two TFs (activating TF 3 (ATF3) and HLF) were predicted, with HSPB1 targeted by ATF3. In addition, 26 genes that were found to be significantly correlated with the overall survival of HCC patients were screened, including CDC20 and thyroid hormone receptor interactor 13. Several genes associated with HCC progression and ferroptosis were screened based on a comprehensive bioinformatics analysis. These genes played roles in HCC progression and ferroptosis via the negative regulation of the ERK1 and ERK2 cascades; the NAD biosynthetic process; and alanine, aspartate, and glutamate metabolism. ATF3 and HSPB1 played important roles in HCC progression and ferroptosis, with HSPB1 possibly regulated by ATF3.

Acyl-CoA thioesterase 1 prevents cardiomyocytes from Doxorubicin-induced ferroptosis via shaping the lipid composition

In this study, we first established the doxorubicin-induced cardiotoxicity (DIC) model with C57BL/6 mice and confirmed cardiac dysfunction with transthoracic echocardiography examination. RNA-sequencing was then performed to explore the potential mechanisms and transcriptional changes in the process. The metabolic pathway, biosynthesis of polyunsaturated fatty acid was significantly altered in DOX-treated murine heart, and Acot1 was one of the leading-edge core genes. We then investigated the role of Acot1 to ferroptosis that was reported recently to be related to DIC. The induction of ferroptosis in the DOX-treated heart was confirmed by transmission electron microscopy, and the inhibition of ferroptosis using Fer-1 effectively prevented the cardiac injury as well as the ultrastructure changes of cardiomyocyte mitochondrial. Both in vitro and in vivo experiments proved the downregulation of Acot1 in DIC, which can be partially prevented with Fer-1 treatment. Overexpression of Acot1 in cell lines showed noteworthy protection to ferroptosis, while the knock-down of Acot1 sensitized cardiomyocytes to ferroptosis by DIC. Finally, the heart tissue of αMHC-Acot1 transgenic mice presented altered free fatty acid composition, indicating that the benefit of Acot1 in the inhibition of ferroptosis lies biochemically and relates to its enzymatic function in lipid metabolism in DIC. The current study highlights the importance of ferroptosis in DIC and points out the potential protective role of Acot1 in the process. The beneficial role of Acot1 may be related to its biochemical function by shaping the lipid composition. In all, Acot1 may become a potential treating target in preventing DIC by anti-ferroptosis.

Selective covalent targeting of GPX4 using masked nitrile-oxide electrophiles

We recently described glutathione peroxidase 4 (GPX4) as a promising target for killing therapy-resistant cancer cells via ferroptosis. The onset of therapy resistance by multiple types of treatment results in a stable cell state marked by high levels of polyunsaturated lipids and an acquired dependency on GPX4. Unfortunately, all existing inhibitors of GPX4 act covalently via a reactive alkyl chloride moiety that confers poor selectivity and pharmacokinetic properties. Here, we report our discovery that masked nitrile-oxide electrophiles, which have not been explored previously as covalent cellular probes, undergo remarkable chemical transformations in cells and provide an effective strategy for selective targeting of GPX4. The new GPX4-inhibiting compounds we describe exhibit unexpected proteome-wide selectivity and, in some instances, vastly improved physiochemical and pharmacokinetic properties compared to existing chloroacetamide-based GPX4 inhibitors. These features make them superior tool compounds for biological interrogation of ferroptosis and constitute starting points for development of improved inhibitors of GPX4.

Peroxiredoxin 5 deficiency exacerbates iron overload-induced neuronal death via ER-mediated mitochondrial fission in mouse hippocampus

Iron is an essential element for cellular functions, including those of neuronal cells. However, an imbalance of iron homeostasis, such as iron overload, has been observed in several neurodegenerative diseases, including Alzheimer’s disease and Parkinson’s disease. Iron overload causes neuronal toxicity through mitochondrial fission, dysregulation of Ca²⁺, ER-stress, and ROS production. Nevertheless, the precise mechanisms between iron-induced oxidative stress and iron toxicity related to mitochondria and endoplasmic reticulum (ER) in vivo are not fully understood. Here, we demonstrate the role of peroxiredoxin 5 (Prx5) in iron overload-induced neurotoxicity using Prx5-deficient mice. Iron concentrations and ROS levels in mice fed a high iron diet were significantly higher in Prx5^−/− mice than wildtype (WT) mice. Prx5 deficiency also exacerbated ER-stress and ER-mediated mitochondrial fission via Ca²⁺/calcineurin-mediated dephosphorylation of Drp1 at Serine 637. Moreover, immunoreactive levels of cleaved caspase3 in the CA3 region of the hippocampus were higher in iron-loaded Prx5^−/− mice than WT mice. Furthermore, treatment with N-acetyl-cysteine, a reactive oxygen species (ROS) scavenger, attenuated iron overload-induced hippocampal damage by inhibiting ROS production, ER-stress, and mitochondrial fission in iron-loaded Prx5^−/− mice. Therefore, we suggest that iron overload-induced oxidative stress and ER-mediated mitochondrial fission may be essential for understanding iron-mediated neuronal cell death in the hippocampus and that Prx5 may be useful as a novel therapeutic target in the treatment of iron overload-mediated diseases and neurodegenerative diseases.

DJ-1 suppresses ferroptosis through preserving the activity of S-adenosyl homocysteine hydrolase

Ferroptosis is a newly characterized form of regulated cell death mediated by iron-dependent accumulation of lipid reactive oxygen species and holds great potential for cancer therapy. However, the molecular mechanisms underlying ferroptosis remain largely elusive. In this study, we define an integrative role of DJ-1 in ferroptosis. Inhibition of DJ-1 potently enhances the sensitivity of tumor cells to ferroptosis inducers both in vitro and in vivo. Metabolic analysis and metabolite rescue assay reveal that DJ-1 depletion inhibits the transsulfuration pathway by disrupting the formation of the S-adenosyl homocysteine hydrolase tetramer and impairing its activity. Consequently, more ferroptosis is induced when homocysteine generation is decreased, which might be the only source of glutathione biosynthesis when cystine uptake is blocked. Thus, our findings show that DJ-1 determines the response of cancer cells to ferroptosis, and highlight a candidate therapeutic target to potentially improve the effect of ferroptosis-based antitumor therapy.

H-Ferritin is essential for macrophages' capacity to store or detoxify exogenously added iron

Macrophages are central cells both in the immune response and in iron homeostasis. Iron is both essential and potentially toxic. Therefore, iron acquisition, transport, storage, and release are tightly regulated, by several important proteins. Cytosolic ferritin is an iron storage protein composed of 24 subunits of either the L- or the H-type chains. H-ferritin differs from L-ferritin in the capacity to oxidize Fe²⁺ to Fe³⁺. In this work, we investigated the role played by H-ferritin in the macrophages’ ability to respond to immune stimuli and to deal with exogenously added iron. We used mice with a conditional deletion of the H-ferritin gene in the myeloid lineage to obtain bone marrow-derived macrophages. These macrophages had normal viability and gene expression under basal culture conditions. However, when treated with interferon-gamma and lipopolysaccharide they had a lower activation of Nitric Oxide Synthase 2. Furthermore, H-ferritin-deficient macrophages had a higher sensitivity to iron-induced toxicity. This sensitivity was associated with a lower intracellular iron accumulation but a higher production of reactive oxygen species. These data indicate that H-ferritin modulates macrophage response to immune stimuli and that it plays an essential role in protection against iron-induced oxidative stress and cell death.

The iron chelator Deferasirox causes severe mitochondrial swelling without depolarization due to a specific effect on inner membrane permeability

The iron chelator Deferasirox (DFX) causes severe toxicity in patients for reasons that were previously unexplained. Here, using the kidney as a clinically relevant in vivo model for toxicity together with a broad range of experimental techniques, including live cell imaging and in vitro biophysical models, we show that DFX causes partial uncoupling and dramatic swelling of mitochondria, but without depolarization or opening of the mitochondrial permeability transition pore. This effect is explained by an increase in inner mitochondrial membrane (IMM) permeability to protons, but not small molecules. The movement of water into mitochondria is prevented by altering intracellular osmotic gradients. Other clinically used iron chelators do not produce mitochondrial swelling. Thus, DFX causes organ toxicity due to an off-target effect on the IMM, which has major adverse consequences for mitochondrial volume regulation.

Frataxin deficiency induces lipid accumulation and affects thermogenesis in brown adipose tissue

Decreased expression of mitochondrial frataxin (FXN) causes Friedreich's ataxia (FRDA), a neurodegenerative disease with type 2 diabetes (T2D) as severe comorbidity. Brown adipose tissue (BAT) is a mitochondria-enriched and anti-diabetic tissue that turns excess energy into heat to maintain metabolic homeostasis. Here we report that the FXN knock-in/knock-out (KIKO) mouse shows hyperlipidemia, reduced energy expenditure and insulin sensitivity, and elevated plasma leptin, recapitulating T2D-like signatures. FXN deficiency leads to disrupted mitochondrial ultrastructure and oxygen consumption as well as lipid accumulation in BAT. Transcriptomic data highlights cold intolerance in association with iron-mediated cell death (ferroptosis). Impaired PKA-mediated lipolysis and expression of genes controlling mitochondrial metabolism, lipid catabolism and adipogenesis were observed in BAT of KIKO mice as well as in FXN-deficient T37i brown and primary adipocytes. Significant susceptibility to ferroptosis was observed in adipocyte precursors that showed increased lipid peroxidation and decreased glutathione peroxidase 4. Collectively our data point to BAT dysfunction in FRDA and suggest BAT as promising therapeutic target to overcome T2D in FRDA.

The role of ferroptosis in ionizing radiation-induced cell death and tumor suppression

Ferroptosis, a form of regulated cell death caused by lipid peroxidation, was recently identified as a natural tumor suppression mechanism. Here, we show that ionizing radiation (IR) induces ferroptosis in cancer cells. Mechanistically, IR induces not only reactive oxygen species (ROS) but also the expression of ACSL4, a lipid metabolism enzyme required for ferroptosis, resulting in elevated lipid peroxidation and ferroptosis. ACSL4 ablation largely abolishes IR-induced ferroptosis and promotes radioresistance. IR also induces the expression of ferroptosis inhibitors, including SLC7A11 and GPX4, as an adaptive response. IR- or KEAP1 deficiency-induced SLC7A11 expression promotes radioresistance through inhibiting ferroptosis. Inactivating SLC7A11 or GPX4 with ferroptosis inducers (FINs) sensitizes radioresistant cancer cells and xenograft tumors to IR. Furthermore, radiotherapy induces ferroptosis in cancer patients, and increased ferroptosis correlates with better response and longer survival to radiotherapy in cancer patients. Our study reveals a previously unrecognized link between IR and ferroptosis and indicates that further exploration of the combination of radiotherapy and FINs in cancer treatment is warranted.

Artemisinin compounds sensitize cancer cells to ferroptosis by regulating iron homeostasis

The antimalarial drug artemisinin and its derivatives have been explored as potential anticancer agents, but their underlying mechanisms are controversial. In this study, we found that artemisinin compounds can sensitize cancer cells to ferroptosis, a new form of programmed cell death driven by iron-dependent lipid peroxidation. Mechanistically, dihydroartemisinin (DAT) can induce lysosomal degradation of ferritin in an autophagy-independent manner, increasing the cellular free iron level and causing cells to become more sensitive to ferroptosis. Further, by associating with cellular free iron and thus stimulating the binding of iron-regulatory proteins (IRPs) with mRNA molecules containing iron-responsive element (IRE) sequences, DAT impinges on IRP/IRE-controlled iron homeostasis to further increase cellular free iron. Importantly, in both in vitro and a mouse xenograft model in which ferroptosis was triggered in cancer cells by the inducible knockout of GPX4, we found that DAT can augment GPX4 inhibition-induced ferroptosis in a cohort of cancer cells that are otherwise highly resistant to ferroptosis. Collectively, artemisinin compounds can sensitize cells to ferroptosis by regulating cellular iron homeostasis. Our findings can be exploited clinically to enhance the effect of future ferroptosis-inducing cancer therapies.

Serum carotenoids and vitamins and risk of cervical dysplasia from a case-control study in Japan

The relationships between risk of cervical dysplasia and dietary and serum carotenoids and vitamins were investigated in a case-control study. Cases were 156 women who attended Papanicolaou test screening in nine institutes affiliated with Japan Study Group of Human Papillomavirus (HPV) and Cervical Cancer and had cervical dysplasia newly histologically confirmed. Age-matched controls were selected from women with normal cervical cytology attending the same clinic. Blood sample and cervical exfoliated cells were obtained for measuring serum retinol, alpha-carotene, beta-carotene, zeaxanthin/lutein, cryptoxanthin, lycopene and alpha-tocopherol and for HPV detection. Higher serum level of alpha-carotene was significantly associated with decreased risk of cervical dysplasia after controlling for HPV infection and smoking status (odds ratio (OR) = 0.16, 95% confidence interval (CI) 0.04-0.62 for the highest as compared with the lowest tertile). Decreased risk for the highest tertile of serum lycopene (OR = 0.28) was marginally significant. Decreased risks observed for the highest tertiles of beta-carotene (OR = 0.65) and zeaxanthin/lutein (OR = 0.53), were not statistically significant.

Serum retinol level and risk of subsequent cervical cancer in cases with cervical dysplasia

We followed up on 134 women who had been diagnosed with cervical dysplasia to examine the relationship of dietary and serum vitamin A to subsequent cervical cancer. The subjects were women attending the Papanicolaou test screening for residents in Miyagi, Japan and histologically diagnosed as having cervical dysplasia between October 1987 and September 1988. Personal interviews were carried out, and blood samples were taken on the date of diagnosis of cervical dysplasia. The subjects were followed-up with cervical smear and colposcopy at about 3-month intervals from the date of interview until the end of February 1995. During the follow-up, 8 women (5.9%) developed cancer in situ or invasive cervical cancer and 106 (79.1%) reverted to normal. The rate of progression of the cancer in situ or invasive cervical cancer was 4.5 times higher in women with lower serum retinol levels than those with higher serum retinol levels (p = 0.08). The results suggest an association of low serum retinol level with development of cervical cancer.

Decreased serum retinol levels in women with cervical dysplasia

To examine the relationship of dietary and serum vitamin A to the risk of cervical dysplasia, a case-control study was conducted in Miyagi, Japan. Cases were 137 women who were found by Papanicolaou test screening and histological examination provided by Miyagi Cancer Society between October 1987 and September 1988 to have cervical dysplasia. Controls were selected from participants of the general health examination provided by the Society and individually matched to cases on age and screening date. The consumption of retinol or carotene-rich foods during the past 7 days was assessed at interview. Information was also collected about other risk factors of cervical dysplasia, such as reproductive histories and sexual behaviour. The mean serum retinol levels were significantly lower among cases compared with controls, although dietary intake levels of retinol and carotene were not different between the two groups. When examined by tertile, the risk of cervical dysplasia was significantly higher among women in the highest tertile of dietary vitamin A level. An inverse association was observed between serum retinol level and risk of cervical dysplasia, although it did not achieve statistical significance.

Risk factors for invasive cervix cancer in young women

The aim of the study was to evaluate risk factors for invasive cervix cancer in young British women and to look for factors which might explain its increased incidence in younger ages. A case-control study involving 121 women with invasive cervix cancer diagnosed before the age of 40 years, and 241 matched controls was undertaken. Questions were asked about demography, sexual behaviour, reproductive and contraceptive history, smoking, diet and hygiene. Age at first intercourse and lifetime number of sexual partners were found to be the most important factors, whereas parity, educational attainment and social class were not related to risk. Smoking was only weakly related to risk (P = 0.01) and this effect disappeared after adjustment for sexual behaviour variables. A weak protective effective of increased fruit consumption was observed (P = 0.03), but again this became non-significant after adjustment for sexual behaviour. Only factors related to sexual behaviour were found to be important in this study and other cofactors often associated with invasive cancer in older women were not found to be involved. It is possible that genetic factors influencing viral persistence, and specific more virulent strains of human papillomavirus may be more important in early onset cases.

Serum carotene, vitamin A, and vitamin C levels in breast cancer and cancer of the uterine cervix

Levels of carotene, vitamin A, and vitamin C measured in the serum of patients with cancer of the breast and uterine cervix were compared with levels in healthy controls and patients with benign diseases of the breast and cervix. Serum ascorbate levels were significantly lower in patients with benign diseases of the breast and cervix than in controls. In cancer patients, there was a significant trend of lower serum vitamin levels with increasing stage of the disease.

Nutrition and cervical neoplasia

Epidemiologic evidence on the relation between nutrition and cervical cancer is reviewed. Cervical cancer is the leading cancer among women in many developing countries, and remains a major public health problem worldwide. This review of nutritional research on cervical neoplasia encompasses the range of epithelial abnormalities from early preneoplastic lesions to invasive cancer. Identified risk factors for cervical neoplasia suggest a multifactorial etiology with several cancer-associated human papillomaviruses (HPV) as the central cause. Studies of nutritional predictors of cervical neoplasia to date, however, have been limited by inadequate HPV measures, which compromise the interpretations of findings. Current research using accurate measures of HPV will be most revealing. Nonetheless, agreement in findings from previous studies suggest a role for nutritional factors in some or all stages of cervical neoplasia. Low vitamin C and carotenoid status are associated fairly consistently with both cervical cancer and precursors, whereas results for vitamin E status are less consistent. The effect of folate status may be restricted to early preneoplastic cervical lesions and not to more advanced disease. Current research is addressing nutritional influences on HPV infection and persistence and on progression of cervical disease. Limitations and recommendations for future research directions are discussed in light of methodologic issues related to nutritional and HPV research.

Use of antioxidant supplements in the treatment of human oral leukoplakia

An increasing public awareness of antioxidants may prompt a patient's request to be treated without surgery if a leukoplakic lesion is discovered. However, surgical excision remains the treatment of choice for oral leukoplakia. The use of antioxidant supplements has shown some promise, but the predictability of success remains uncertain and long-term results are unavailable. Before the decision to use any antioxidant is made, it is critical to obtain a histopathologic diagnosis of the lesion. When dealing with a lesion diagnosed as hyperkeratosis, it may be appropriate to choose an antioxidant that may take some time for clinical improvement to occur. However, as the grade of epithelial dysplasia becomes more severe, consideration must be given to the possibility of malignant transformation during antioxidant treatment. We do not recommend the use of antioxidant supplements in the treatment of any carcinoma. The therapeutic use of antioxidant supplements outside of clinical trials conducted at academic medical centers should be done with considerable caution by practitioners in private practice. It should be emphasized that in these clinical trial patients were seen at frequent intervals to monitor their progress and to intervene if there was a noticeable deterioration in the clinical appearance of the lesion. In spite of the uncertainty with respect to antioxidant treatment, there are circumstances in which it should be considered. Recurrence after surgical excision when there is little reason to believe that a second surgical excision would be any more successful is an ideal candidate. Also, patients with widespread leukoplakia that involves a large area of the oral mucosa might be suitable for treatment with antioxidants, as well as patients who have extensive medical problems that make them surgical risks. The choice of which antioxidant(s) to use is complex because thus far there is no combination that is superior to the others. Beta-carotene with ascorbic acid or alpha-tocopherol is attractive because of a lack of side effects, but the range in reported values for lesion improvement has been broad and the clinical improvement typically takes several months. Clinical response with 13-cRA is faster but requires baseline and periodic serologic testing, as well as close monitoring for side effects. In those circumstances in which time is an important consideration, 13-cRA might be useful because clinical improvement can be evaluated within a matter of weeks as compared with beta-carotene. The group from M.D. Anderson Hospital has shown the value of an induction dose of 13-cRA that is followed by a lower maintenance dose. Unfortunately, the problem of recurrence after discontinuation of 13-cRA is quite common. One aspect that has not been evaluated is the combination of conventional surgical excision and the administration of postoperative antioxidants. This would have the obvious advantage of conventional treatment of surgery together with the possible protective effect of the antioxidants. Although this is an attractive hypothesis, we do not know of any studies that have proven this to be beneficial.

Epidemiology of cervical intraepithelial neoplasia: the role of human papillomavirus

The evidence implicating specific HPV types in the aetiology of cervical cancer is now strong enough to establish a causative role. HPV infection of the cervix affects the developing immature metaplastic cells of the transformation zone. Cervical neoplasia can be viewed as the interaction of high risk papillomavirus and immature metaplastic epithelium. Once maturity is reached, there is minimal risk of subsequent development of cervical squamous neoplasia. Exposure to HPV is an extremely common event, especially in young sexually active women. Yet, despite frequent HPV exposure at that phase of life in which the cervical transformation zone is at its most vulnerable, established expressed disease is relatively uncommon. Most studies in which the natural history of CIN is not altered by cervical biopsy reveal a progression rate from low to high grade CIN of less than one third. Where viral type is taken into account, however, the progression rate from normal but high risk HPV-infected cervical epithelium to CIN 2 or 3 is higher. Despite this, most cervical abnormalities will not transform into invasive cancer, even if left untreated. The variance between the high rate of HPV infection, the intermediate rate of CIN and the relatively low rate of cervical cancer establishes a stepwise gradient of disease of increasing severity with decreasing prevalence. In an immunocompetent host, HPV infection alone does not appear to be sufficient to induce the step from high grade CIN to invasion. Epidemiological studies indicating that HPV infection with oncogenic viral types is far more common than cervical neoplasia suggest the necessity of cofactors in cervical carcinogenesis. The long time-lag between initial infection and eventual malignant conversion suggests that random events may be necessary for such conversion, and the spontaneous regression of many primary lesions suggests that most patients are not exposed to these random events. Potential cofactors include cigarette smoking, hormonal effects of oral contraceptives and pregnancy, dietary deficiencies, immunosuppression and chronic inflammation. In those women who develop cervical cancer, malignant progression is rarely rapid, more commonly taking many years or decades. Malignant progression has been documented in patients who presented initially with only low grade HPV-induced atypia. On the other hand, progression may be a misnomer, as 'apparent' progression may really represent adjacent 'de novo' development of higher grade CIN. Although most cervical cancers contain high risk HPV types, up to 15% of such cancers test negative for HPV, raising the possibility that a few, usually more aggressive, cervical cancers may arise from from a non-viral source.(ABSTRACT TRUNCATED AT 400 WORDS)

Nutrient antioxidants in the pathogenesis and prevention of cervical dysplasias and cancer

The role of nutritional factors in biochemical interactions that are part of an oncogenic process or inhibit free radical proliferation have attracted considerable interest in relation to molecular mechanism(s) and the natural history of human cancer. Epidemiologic and experimental studies have drawn attention to the association between dietary micronutrient deficiencies and the incidence of neoplastic and malignant lesions. In the last two decades, the role(s) of retinoids, carotenoids, tocopherols and water-soluble antioxidant vitamins, and allegations of anti-tumor properties in the daily dietary consumption of fresh fruits and green leafy vegetables, have captured the attention of an increasingly sensitive diet- and health care-conscious public, the biochemical community, and industrial food producers. Moreover, recent epidemiologic and compelling advances in molecular biology have linked the presence of restricted human papillomavirus (HPV) subtypes to cervical carcinoma and precursor lesions. In the present report, we identify and review measurable effects of dietary deficiencies of selected antioxidant micronutrients (i.e., beta-carotene and vitamins A, C, and E) and their association with known cervix cancer risk factors in the pathogenesis and potential prevention of cervix dysplasias, presumed to be the precursor lesions of cervix cancer.

A review of the use of antioxidant supplements in the treatment of human oral leukoplakia

Over the past twenty years, research into the role of antioxidants in the prevention of cancer has increased dramatically. The use of antioxidant supplements to treat oral leukoplakia has gained acceptance due to the success demonstrated in several clinical trials. This review discusses the role of antioxidants in the development of cancer and their possible use in the treatment of oral leukoplakia.

The prevalence of oral lesions in smokeless tobacco users and an evaluation of risk factors

BACKGROUND

The widespread use of smokeless tobacco (ST) has prompted concern in regard to the development of oral lesions in long-term users.

METHODS

For inclusion in the current study, a subject must have used an ST product, either snuff or chewing tobacco, for at least 6 months. The subjects were recruited by advertising, and none was referred for the evaluation of an oral lesion. The following were performed on all subjects: assessment of exposure to ST, cigarettes, and alcohol; examination of the oral cavity; a biopsy, if an oral lesion was found; and analysis of a blood sample for beta-carotene. The dietary intake of most of the subjects was analyzed.

RESULTS

Of the 347 ST users, all of whom were white male subjects, 45 (13.0%) had an oral lesion. Thirty-five of the lesions were hyperkeratosis and 10 were epithelial dysplasia.

CONCLUSIONS

Snuff exposure was associated significantly with the presence of an oral lesion (P < 0.0001). A decreased vitamin C intake also was found among the ST users with oral lesions (P < 0.01). The ST users with epithelial dysplasia, as compared with those with hyperkeratotic lesions, were slightly older, had a lower intake of vitamin C (P < 0.05), and were more likely to have used chewing tobacco than snuff.

Factors influencing the exfoliation of cervicovaginal epithelial cells

OBJECTIVE

Our objective was to investigate the association of smoking and exfoliation of cervicovaginal epithelial cells while controlling for other factors that may potentially influence cell exfoliation (e.g., presence of cervical intraepithelial neoplasia or koilocytes, the use of oral contraceptives, age, and the phase of the menstrual cycle).

STUDY DESIGN

Cervicovaginal lavage specimens and epidemiologic questionnaires were obtained with informed consent from 190 women. The cervicovaginal lavage samples were processed to separate other contaminants. The number of squamous epithelial cells counted was expressed as cells per milliliter of lavage.

RESULTS

Multiple linear regression analysis revealed that the number of exfoliated epithelial cells was significantly higher in smokers (p < 0.01) and also in women with cervical intraepithelial neoplasia (p < 0.05). The other studied variables had no detectable effect.

CONCLUSION

The findings suggest that smoking or the presence of cervical intraepithelial neoplasia may induce an acceleration in the exfoliation of cervicovaginal epithelial cells. This may alter cell maturation and may be a factor in the oncogenic process.

Beta-carotene levels in exfoliated cervicovaginal epithelial cells in cervical intraepithelial neoplasia and cervical cancer

OBJECTIVE

The purpose of this study was to measure beta-carotene levels in exfoliated epithelial cervicovaginal cells collected by a lavage technique in normal women and patients with histopathologically diagnosed cervical intraepithelial neoplasia and cervical cancer.

STUDY DESIGN

In a cross-sectional sampling of women (n = 105), cervicovaginal cells and plasma beta-carotene levels were assayed with high-pressure liquid chromatography. In addition, beta-carotene levels were measured in exfoliated epithelial samples of cervicovaginal cells obtained from women (n = 24) enrolled in an ongoing oral beta-carotene supplementation clinical trial.

RESULTS

Cervicovaginal cells and plasma beta-carotene levels were found to be significantly decreased in women with cervical intraepithelial neoplasia and cervical cancer as compared with controls (p < 0.0001, analysis of variance). Retinol levels in cervicovaginal cells were undetectable. The beta-carotene levels in cervicovaginal cells were markedly increased in the majority of patients (79%) after oral supplementation as compared with baseline levels in women enrolled in the beta-carotene clinical trial.

CONCLUSION

The study demonstrates that changes of in situ cellular beta-carotene concentrations are measurable in samples of exfoliated epithelial cells obtained by a noninvasive saline lavage harvesting technique. The current findings further support our previous hypothesis that beta-carotene deficiency may have an etiologic role in the pathogenesis of cervical intraepithelial neoplasia and/or cervical cancer.

Genital human papillomavirus infection in women

OBJECTIVE

To enhance nurse clinicians' knowledge of genital human papillomavirus infection in women.

DATA SOURCES

Several literature searches using the following terms, dating back to 1986: human papillomavirus (HPV), females, human, cervical neoplasia, risk factors, condylomata acuminata, detection, epidemiology, pathology, psychology, Papanicolaou test, immunosuppression, HIV infection, and AIDS.

STUDY SELECTIONS

Forty-three formal research studies regarding the association of various types of HPV infection with cervical intraepithelial lesions, the putative precursor lesions for cervical neoplasia; the outcomes of diagnostic techniques for HPV types; the outcomes of diagnostic/screening techniques for abnormal cervical cells; the association of risk factors for acquiring HPV infection; or the outcomes of therapy. Some additional references were chosen for their presentation of epidemiologic or surveillance data, others for their scientific discussions on related topics.

DATA EXTRACTION

Data were abstracted according to summary measures of the parameter of interest in the sample studied. In most instances, it was the prevalence of HPV, cervical neoplasia, or frequency of use of screening tests.

DATA SYNTHESIS

Immunosuppressed clients are at particular risk for HPV-mediated cervical neoplasia.

CONCLUSION

Because Papanicolaou tests are an effective screening tool, cervical cancer is easily detectable. The nurse may facilitate treatment. This is an especially important issue for young women, among whom sexual activity is growing--with attendant increases of HPV and HIV infection.

Social class, marital status, and cancer of the uterine cervix in England and Wales, 1950-1983

STUDY OBJECTIVE

The aim was to investigate whether trends in mortality from cancer of the cervix uteri by age, marital status, and social class are compatible with current beliefs about the epidemiology of the disease.

DESIGN

Data on mortality from cancer of the cervix for single and married women by age and social class were obtained from the Registrar General's Decennial Supplements on occupational mortality for the years 1950-53, 1959-63, 1970-72, and 1979, 1980, 1982, and 1983. Age standardised mortality rates were calculated directly by social class and marital status.

SETTING

The data relate to all cases of carcinoma of the cervix reported in England and Wales in the years studied.

MAIN RESULTS

There was a marked convergence of mortality between single and married women over the period within every social class grouping examined. The social class differential, however, remained essentially unchanged for both single and married women considered separately.

CONCLUSIONS

Trends in mortality by marital status appear to reflect accurately the changes in the pattern of marriage and sexual behaviour that have taken place in the post-war period, whereas the patterns of other risk and protective factors such as screening explain these trends less well. In contrast, it seems likely that factors other than patterns of sexual behaviour and screening operate to maintain the social class differential in England and Wales.

Diet and the risk of in situ cervical cancer among white women in the United States

A case-control study of women with incident in situ and invasive cervical cancer was conducted during 1982-83 in five US areas reporting to the Comprehensive Cancer Patient Data System: Birmingham, AL; Chicago, IL; Denver, CO; Miami, FL; and Philadelphia, PA. Controls were selected by random-digit dialing and matched to invasive cases on age, race, and telephone exchange. Of the white non-Hispanic in situ cases and controls identified, 229 (78 percent) and 502 (74 percent) were successfully interviewed. Diet was assessed by asking about the usual adult frequency of consumption of 75 food items and the use of vitamin supplements. Included were the major sources of the four micronutrients postulated to reduce the risk of cervical cancer: carotenoids, vitamin A, vitamin C, and folate. Weak inverse associations between risk of in situ disease and intake of carotenoids, vitamin C, folate, fruit, and vegetables/fruits were noted but, with further analysis, these seemed attributable to residual confounding by the multiple lifestyle-related risk factors for this disease and possibly to selection bias. Vitamin A and vegetable intake were unrelated to risk. Dark yellow-orange vegetable consumption and duration of multivitamin use were each strongly related to reduced risk of in situ disease (P for trend = 0.02 and 0.002, respectively) and need to be evaluated in other studies. The absence of persuasive protective effects for the four micronutrients and the similar findings from our analysis of invasive cervical cancer do not concur with other epidemiologic studies and suggest that the role of diet and nutrition in the etiology of cervical cancer is not yet resolved.

Plasma levels of antioxidant beta-carotene and alpha-tocopherol in uterine cervix dysplasias and cancer

Chronic human health problems, namely arteriosclerosis, myocardial ischemia, and cancer, may be caused by highly active oxygen species and may be preventable by antioxidant vitamins. In humans, the sources of two major antioxidants, beta-carotene and alpha-tocopherol, are dietary. In this study, we measured the plasma concentrations of beta-carotene and alpha-tocopherol by reverse-phase high-pressure liquid chromatography in a cross-sectional sampling of 116 women. Significantly reduced plasma levels of beta-carotene and alpha-tocopherol were observed in women with histopathologically diagnosed cervical dysplasias or cancer (p less than 0.0001 and p less than 0.005, respectively). There was an inverse association between the plasma levels of both beta-carotene and alpha-tocopherol and increasingly severe graded cervical histopathology. In groups with advanced dysplasias, the percentage of smokers was markedly increased and the women were comparatively older (p less than 0.0001). A strong association was noted between smoking status and plasma beta-carotene levels, independent of cervical pathology. However, this was not evident with respect to alpha-tocopherol. The findings suggest that the antioxidants beta-carotene and alpha-tocopherol have biologic functions that are interdependent in the pathogenesis of cervical intraepithelial lesions and cervical cancer.