Cancer related mutations in NRF2 impair its recognition by Keap1-Cul3 E3 ligase and promote malignancy. Proc Natl Acad Sci U S A. 2008;105:13568-13573. [PMID: 18757741 DOI: 10.1073/pnas.0806268105]

Thirty years of NRF2: advances and therapeutic challenges

Over the last 30 years, NRF2 has evolved from being recognized as a transcription factor primarily involved in redox balance and detoxification to a well-appreciated master regulator of cellular proteostasis, metabolism and iron homeostasis. NRF2 plays a pivotal role in diverse pathologies, including cancer, and metabolic, inflammatory and neurodegenerative disorders. It exhibits a Janus-faced duality, safeguarding cellular integrity in normal cells against environmental insults to prevent disease onset, whereas in certain cancers, constitutively elevated NRF2 levels provide a tumour survival advantage, promoting progression, therapy resistance and metastasis. Advances in understanding the mechanistic regulation of NRF2 and its roles in human pathology have propelled the investigation of NRF2-targeted therapeutic strategies. This Review dissects the mechanistic intricacies of NRF2 signalling, its cross-talk with biological processes and its far-reaching implications for health and disease, highlighting key discoveries that have shaped innovative therapeutic approaches targeting NRF2.

Data-Driven Molecular Typing: A New Frontier in Esophageal Cancer Management

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is a predominant and highly lethal form of esophageal cancer, with a five-year survival rate below 20%. Despite advancements, most patients are diagnosed at advanced stages, limiting effective treatment options. Multi-omics integration, encompassing somatic genomic alterations, inherited genetic mutations, transcriptomics, proteomics, metabolomics, and single-cell sequencing, has enabled the identification of distinct molecular subtypes of ESCC.

METHOD

This article systematically reviewed the current status of molecular subtyping of ESCC based on big data, summarized unique subtypes with differing treatment responses and prognostic outcomes.

RESULT

Key findings included subtype-specific genetic mutations, signaling pathway alterations, and metabolomic profiles, which offer novel biomarkers and therapeutic targets. Furthermore, this review discusses the link between molecular subtypes and immunotherapy efficacy, chemotherapy response, and drug development.

CONCLUSION

These insights highlight the potential of omics-based molecular typing to transform ESCC management and facilitate personalized treatment strategies.

The role of NRF2 function and regulation in atherosclerosis: an update

Atherosclerosis, a chronic inflammatory disease of the arteries, remains a leading cause of cardiovascular morbidity and mortality worldwide. This review examines the molecular mechanisms underlying NRF2 role in atherosclerosis, focusing on the recently defined intricate interplay between autophagy, the nuclear factor erythroid 2-related factor 2 (NRF2) pathway, microRNAs (miRNAs), and genes regulating NRF2 with atheroprotective effects. The NRF2/autophagy axis emerges as a critical regulator of cellular responses to oxidative stress and inflammation in atherosclerosis, with key players including Heat Shock Protein 90 (HSP90), Neuropeptide Y (NPY), and Glutaredoxin 2 (GLRX2). MiRNAs are identified as potent regulators of gene expression in atherosclerosis, impacting NRF2 signalling and disease susceptibility. Additionally, genes such as Prenyl diphosphate synthase subunit 2 (PDSS2), Sulfiredoxin1 (Srxn1), and Isocitrate dehydrogenase 1 (IDH1) are implicated in NRF2-dependent atheroprotective pathways. Future research directions include elucidating the complex interactions between these molecular pathways, evaluating novel therapeutic targets in preclinical and clinical settings, and addressing challenges related to drug delivery and patient heterogeneity. Despite limitations, this review underscores the potential for targeted interventions aimed at modulating NRF2/autophagy signalling and miRNA regulatory networks to mitigate atherosclerosis progression and improve cardiovascular outcomes.

NRF-mediated autophagy and UPR: Exploring new avenues to overcome cancer chemo-resistance

The development of chemo-resistance remains a significant hurdle in effective cancer therapy. NRF1 and NRF2, key regulators of redox homeostasis, play crucial roles in the cellular response to oxidative stress, with implications for both tumor growth and resistance to chemotherapy. This study delves into the dualistic role of NRF2, exploring its protective functions in normal cells and its paradoxical support of tumor survival and drug resistance in cancerous cells. We investigate the interplay between the PERK/NRF signaling pathway, ER stress, autophagy, and the unfolded protein response, offering a mechanistic perspective on how these processes contribute to chemoresistance. Our findings suggest that targeting NRF signaling pathways may offer new avenues for overcoming resistance to chemotherapeutic agents, highlighting the importance of a nuanced approach to redox regulation in cancer treatment. This research provides a molecular basis for the development of NRF-targeted therapies, potentially enhancing the efficacy of existing cancer treatments and offering hope for more effective management of resistant tumors.

KEAP1-NRF2 Interaction in Cancer: Competitive Interactors and Their Role in Carcinogenesis

An American Cancer Society report estimates the emergence of around 2 million new cancer cases in the US in 2024 [...].

A histochemical approach to activity-based copper sensing reveals cuproplasia-dependent vulnerabilities in cancer

Copper is an essential nutrient for sustaining vital cellular processes spanning respiration, metabolism, and proliferation. However, loss of copper homeostasis, particularly misregulation of loosely bound copper ions which are defined as the labile copper pool, occurs in major diseases such as cancer, where tumor growth and metastasis have a heightened requirement for this metal. To help decipher the role of copper in the etiology of cancer, we report a histochemical activity-based sensing approach that enables systematic, high-throughput profiling of labile copper status across many cell lines in parallel. Coppermycin-1 reacts selectively with Cu(I) to release puromycin, which is then incorporated into nascent peptides during protein translation, thus leaving a permanent and dose-dependent marker for labile copper that can be visualized with standard immunofluorescence assays. We showcase the utility of this platform for screening labile Cu(I) pools across the National Cancer Institute's 60 (NCI-60) human tumor cell line panel, identifying cell types with elevated basal levels of labile copper. Moreover, we use Coppermycin-1 to show that lung cancer cells with heightened activation of nuclear factor-erythroid 2-related factor 2 (NRF2) possess lower resting labile Cu(I) levels and, as a result, have reduced viability when treated with a copper chelator. This work establishes that methods for labile copper detection can be used to assess cuproplasia, an emerging form of copper-dependent cell growth and proliferation, providing a starting point for broader investigations into the roles of transition metal signaling in biology and medicine.

Biomarker potential of nuclear Nrf2 activation in the ABC subtype of diffuse large B‑cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is an aggressive B-cell lymphoma characterized by distinct subtypes and heterogeneous treatment outcomes. Oxidative stress and the dysregulation of related regulatory genes are prevalent in DLBCL, prompting an investigation into the nuclear factor erythroid 2-related factor 2 (Nrf2)-kelch-like ECH-associated protein 1 (Keap1) signaling pathway and associated genes. The present study assessed pathological specimens and clinical data from 43 newly diagnosed patients with DLBCL, comparing the associations and correlations between the expression of Nrf2, Keap1, microtubule-associated protein 1 light chain 3β (LC3B) and nitrotyrosine and the activated B-cell (ABC) and germinal center B-cell (GCB) subtypes of DLBCL using immunohistochemistry and digital image analysis software. Nuclear Nrf2 activation was observed in 33.3% of patients with DLBCL ABC, demonstrating a higher prevalence of hepatitis B surface antigen positivity, calcium ions and significant body weight loss (P<0.05). Total Nrf2 expression was associated with the DLBCL GCB subtype and inversely correlated with Keap1 expression in the DLBCL ABC subtype. Furthermore, a positive correlation was demonstrated between Nrf2 and LC3, indicating that total Nrf2 is inhibited by Keap1 and regulates LC3 expression. The ABC subtype was also associated with lower white blood cell counts and more frequent chemotherapy courses than the GCB subtype. These findings suggest that nuclear Nrf2 could be a biomarker for DLBCL clinical diagnosis.

Splicing junction-based classifier for the detection of abnormal constitutive activation of the KEAP1-NRF2 system

The KEAP1-NRF2 system plays a crucial role in responding to oxidative and electrophilic stress. Its dysregulation can cause the overexpression of downstream genes, a known cancer hallmark. Understanding and detecting abnormal KEAP1-NRF2 activity is essential for understanding disease mechanisms and identifying therapeutic targets. This study presents an approach that analyzes splicing patterns by a naive Bayes-based classifier to identify constitutive activation of the KEAP1-NRF2 system, focusing on the higher presence of abnormal splicing junctions as a subproduct of overexpression of downstream genes. Our splicing-based classifier demonstrated robust performance, reliably identifying activation of the KEAP1-NRF2 pathway across extensive datasets, including The Cancer Genome Atlas and the Sequence Read Archive. This shows the classifier's potential to analyze hundreds of thousands of transcriptomes, highlighting its utility in broad-scale genomic studies and provides a new perspective on utilizing splicing aberrations caused by overexpression as diagnostic markers, offering potential improvements in diagnosis and treatment strategies.

A Core NRF2 Gene Set Defined Through Comprehensive Transcriptomic Analysis Predicts Selective Drug Resistance and Poor Multicancer Prognosis

Aims: The nuclear factor erythroid 2-related factor 2-Kelch-like ECH-associated protein 1 (NRF2-KEAP1) pathway plays an important role in the cellular response to oxidative stress but may also contribute to metabolic changes and drug resistance in cancer. However, despite its pervasiveness and important role, most of nuclear factor erythroid 2-related factor 2 (NRF2) target genes are defined in context-specific experiments and analysis, making it difficult to translate from one situation to another. Our study investigates whether a core NRF2 gene signature can be derived and used to represent NRF2 activation in various contexts, allowing better reproducibility and understanding of NRF2. Results: We define a core set of 14 upregulated NRF2 target genes from 7 RNA-sequencing datasets that we generated and analyzed. This NRF2 gene signature was validated using analyses of published datasets and gene sets. An NRF2 activity score based on expression of these core target genes correlates with resistance to drugs such as PX-12 and necrosulfonamide but not to paclitaxel or bardoxolone methyl. We validated these findings in our Kelch-like ECH-associated protein 1 (KEAP1) knockout cancer cell lines. Finally, our NRF2 score is prognostic for cancer survival and validated in additional independent cohorts for lung adenocarcinoma and also novel cancer types not associated with NRF2-KEAP1 mutations such as clear cell renal carcinoma, hepatocellular carcinoma, and acute myeloid leukemia. Innovation and Conclusions: These analyses define a core NRF2 gene signature that is robust, versatile, and useful for evaluating NRF2 activity and for predicting drug resistance and cancer prognosis. Using this gene signature, we uncovered novel selective drug resistance and cancer prognosis associated with NRF2 activation. Antioxid. Redox Signal. 41, 1031-1050.

Specific cancer types and prognosis in patients with variations in the KEAP1-NRF2 system: A retrospective cohort study

The KEAP1-NRF2 system induces the expression of antioxidant genes in response to various types of oxidative stress. Some cancer cells activate this system, which increases their malignancy through genetic mutations. We performed a retrospective cohort study using the C-CAT database, which contains the gene-panel sequence data from 60,056 cases of diagnosed solid tumors. We analyzed somatic mutations in NRF2 and KEAP1 genes and their associations with clinical outcomes. Variants in the NRF2 gene were clustered in exon 2, which encodes the DLG and ETGE motifs essential for KEAP1 interaction. The NRF2 variants were frequently observed in esophageal and lung squamous cell carcinoma with frequencies of 35.9% and 19.6%, respectively. Among these mutations, the NRF2 variants in the ETGE motif were indicators of a worse prognosis. KEAP1 variants were found in 2.5% of all cases. The variants were frequent in lung cancer and showed a worse prognosis in lung and other types of adenocarcinomas. We then conducted gene expression analysis using TCGA data. While cancers with DLG and ETGE variants were similar in terms of gene expression profiles, there were significant differences between cancers with KEAP1 and NRF2 variants. Our results indicate that genetic alteration of the KEAP1-NRF2 pathway is a major factor in patient prognosis for each cancer type and its genetic variant. Variants in NRF2 and KEAP1 genes can characterize the biological basis of each cancer type and are involved in carcinogenesis, resistance to therapy, and other biological differences.

Lung-MAP Next-Generation Sequencing Analysis of Advanced Squamous Cell Lung Cancers (SWOG S1400)

INTRODUCTION

Squamous cell cancer (SqCC) is a lung cancer subtype with few targeted therapy options. Molecular characterization, that is, by next-generation sequencing (NGS), is needed to identify potential targets. Lung Cancer Master Protocol Southwest Oncology Group S1400 enrolled patients with previously treated stage IV or recurrent SqCC to assess NGS biomarkers for therapeutic sub-studies.

METHODS

Tumors underwent NGS using Foundation Medicine's FoundationOne research platform, which sequenced the exons and/or introns of 313 cancer-related genes. Mutually exclusive gene set analysis and Selected Events Linked by Evolutionary Conditions across Human Tumors were performed to identify mutually exclusive and co-occurring gene alterations. Comparisons were performed with data on 495 lung SqCC downloaded from The Cancer Genome Atlas. Cox proportional hazards models were used to assess associations between genetic variants and survival.

RESULTS

NGS data are reported for 1672 patients enrolled on S1400 between 2014 and 2019. Mutually exclusive gene set analysis identified two non-overlapping sets of mutually exclusive alterations with a false discovery rate of less than 15%: NFE2L2, KEAP1, and PARP4; and CDKN2A and RB1. PARP4, a relatively uncharacterized gene, showed three frequent mutations suggesting functional significance: 3116T>C (I1039T), 3176A>G (Q1059R), and 3509C>T (T1170I). When taken together, NFE2L2 and KEAP1 alterations were associated with poorer survival.

CONCLUSIONS

As the largest dataset to date of lung SqCC profiled on a clinical trial, the S1400 NGS dataset establishes a rich resource for biomarker discovery. Mutual exclusivity of PARP4 and NFE2L2 or KEAP1 alterations suggests that PARP4 may have an uncharacterized role in a key pathway known to impact oxidative stress response and treatment resistance.

Current landscape of targeted therapy in esophageal squamous cell carcinoma

Esophageal cancer is the seventh most common malignancy worldwide and is primarily categorized into adenocarcinoma and squamous cell carcinoma (SCC), with the predominant histological type varying by region. In Western countries, including the United States, adenocarcinoma is more prevalent, whereas in East Asian countries, SCC is more common, with it constituting 86% of cases in Japan. Although there has been an increasing trend of adenocarcinoma in Western populations, SCC still accounts for the majority of esophageal cancer cases globally. Cytotoxic chemotherapy has been the mainstay of treatment, however, targeted therapies including EGFR, FGFR, PI3K, or CDK4/6, despite showing preliminary efficacy signals, have not yet received regulatory approval. Recently, immune checkpoint inhibitors (ICIs) have shown therapeutic efficacy and have been approved as a monotherapy or combination therapy for advanced esophageal SCC (ESCC). Although PD-L1 expression is the only clinically applicable biomarker for first-line therapy with ICIs in ESCC, responses to ICIs are various, and novel predictive biomarkers are under investigation. Furthermore, novel antibody-drug conjugates (ADC) hold promise for advanced ESCC. This review includes the current landscape and future perspectives of potential targeted therapy for advanced ESCC.

Oxidative Stress and Cancer Therapy: Controlling Cancer Cells Using Reactive Oxygen Species

Cancer is a multifaceted disease influenced by various mechanisms, including the generation of reactive oxygen species (ROS), which have a paradoxical role in both promoting cancer progression and serving as targets for therapeutic interventions. At low concentrations, ROS serve as signaling agents that enhance cancer cell proliferation, migration, and resistance to drugs. However, at elevated levels, ROS induce oxidative stress, causing damage to biomolecules and leading to cell death. Cancer cells have developed mechanisms to manage ROS levels, including activating pathways such as NRF2, NF-κB, and PI3K/Akt. This review explores the relationship between ROS and cancer, focusing on cell death mechanisms like apoptosis, ferroptosis, and autophagy, highlighting the potential therapeutic strategies that exploit ROS to target cancer cells.

Targeting ROS-sensing Nrf2 potentiates anti-tumor immunity of intratumoral CD8+ T and CAR-T cells

Cytotoxic T lymphocytes (CTLs) play a crucial role in cancer rejection. However, CTLs encounter dysfunction and exhaustion in the immunosuppressive tumor microenvironment (TME). Although the reactive oxygen species (ROS)-rich TME attenuates CTL function, the underlying molecular mechanism remains poorly understood. The nuclear factor erythroid 2-related 2 (Nrf2) is the ROS-responsible factor implicated in increasing susceptibility to cancer progression. Therefore, we examined how Nrf2 is involved in anti-tumor responses of CD8+ T and chimeric antigen receptor (CAR) T cells in the ROS-rich TME. Here, we demonstrated that tumor growth in Nrf2-/- mice was significantly controlled and was reversed by T cell depletion and further confirmed that Nrf2 deficiency in T cells promotes anti-tumor responses using an adoptive transfer model of antigen-specific CD8+ T cells. Nrf2-deficient CTLs are resistant to ROS, and their effector functions are sustained in the TME. Furthermore, Nrf2 knockdown in human CAR-T cells enhanced the survival and function of intratumoral CAR-T cells in a solid tumor xenograft model and effectively controlled tumor growth. ROS-sensing Nrf2 inhibits the anti-tumor T cell responses, indicating that Nrf2 may be a potential target for T cell immunotherapy strategies against solid tumors.

Isoliquiritigenin as a modulator of the Nrf2 signaling pathway: potential therapeutic implications

Nuclear factor erythroid-2-related factor 2 (Nrf2), a transcription factor responsible for cytoprotection, plays a crucial role in regulating the expression of numerous antioxidant genes, thereby reducing reactive oxygen species (ROS) levels and safeguarding cells against oxidative stress. Extensive research has demonstrated the involvement of Nrf2 in various diseases, prompting the exploration of Nrf2 activation as a potential therapeutic approach for a variety of diseases. Consequently, there has been a surge of interest in investigating the Nrf2 signaling pathway and developing compounds that can modulate its activity. Isoliquiritigenin (ISL) (PubChem CID:638278) exhibits a diverse range of pharmacological activities, including antioxidant, anticancer, and anti-tumor properties. Notably, its robust antioxidant activity has garnered significant attention. Furthermore, ISL has been found to possess therapeutic effects on various diseases, such as diabetes, cardiovascular diseases, kidney diseases, and cancer, through the activation of the Nrf2 pathway. This review aims to evaluate the potential of ISL in modulating the Nrf2 signaling pathway and summarize the role of ISL in diverse diseases prevention and treatment through modulating the Nrf2 signaling pathway.

NRF2 Signaling Pathway in Chemo/Radio/Immuno-Therapy Resistance of Lung Cancer: Looking Beyond the Tip of the Iceberg

Lung cancer is one of the most common causes of cancer death in men and women worldwide. Various combinations of surgery, chemotherapy, radiation therapy and immunotherapy are currently used to treat lung cancer. However, the prognosis remains relatively poor due to the higher frequency of tumor mutational burden (TMB). Nuclear factor E2-related factor 2 (NFE2L2/NRF2) is often considered a primary regulator of the expression of antioxidant enzymes and detoxification proteins and is involved in cytoprotection. On the contrary, NRF2 is even known to induce metastasis and support tumor progression. Kelch-like ECH-associated protein 1 (KEAP1) plays an important role in negatively regulating NRF2 activity via CUL3-mediated ubiquitinylation and successive proteasomal degradation. Extensive research has shown that the genetic alterations of KEAP1/NFE2L2/CUL3 genes lead to increased expression of NRF2 and its target genes in lung cancer. Thus, these studies provide ample evidence for the dual role of NRF2 in lung cancer. In this review, we discussed the mechanistic insights into the role of NRF2 signaling in therapy resistance by focusing on cell lines, mouse models, and translational studies in lung cancer. Finally, we highlighted the potential therapeutic strategies targeting NRF2 inhibition, followed by the discussion of biomarkers related to NRF2 activity in lung cancer. Overall, our article exclusively discusses in detail the NRF2 signaling pathway in resistance to therapy, especially immunotherapy, and its therapeutic avenue in the treatment of lung cancer.

Three Ru(II) complexes modulate the antioxidant transcription factor Nrf2 to overcome cisplatin resistance

Here, we designed, synthesized and characterized three new cyclometalated Ru(II) complexes, [Ru(phen)2(1-(4-Ph-Ph)-IQ)]+ (phen = 1,10-phenanthroline, IQ = isoquinoline, RuIQ9), [Ru(phen)2(1-(4-Ph-Ph)-7-OCH3-IQ)]+ (RuIQ10), and [Ru(phen)2(1-(4-Ph-Ph)-6,7-(OCH3)2-IQ)]+ (RuIQ11). The cytotoxicity experiments conducted on both 2D and 3D multicellular tumor spheroids (MCTSs) indicated that complexes RuIQ9-11 exhibited notably higher cytotoxicity against A549 and A549/DDP cells when compared to the ligands and precursor compounds as well as clinical cisplatin. Moreover, the Ru(II) complexes displayed low toxicity when tested on normal HBE cells in vitro and exposed to zebrafish embryos in vivo. In addition, complexes RuIQ9-11 could inhibit A549 and A549/DDP cell migration and proliferation by causing cell cycle arrest, mitochondrial dysfunction, and elevating ROS levels to induce apoptosis in these cells. Mechanistic studies revealed that RuIQ9-11 could suppress the expression of Nrf2 and its downstream antioxidant protein HO-1 by inhibiting Nrf2 gene transcription in drug-resistant A549/DDP cells. Simultaneously, they inhibited the expression of efflux proteins MRP1 and p-gp in drug-resistant cells, ensuring the accumulation of the complexes within the cells. This led to an increase in intracellular ROS levels in drug-resistant cells, ultimately causing damage and cell death, thus overcoming cisplatin resistance. More importantly, RuIQ11 could effectively inhibit the migration and proliferation of drug-resistant cells within zebrafish, addressing the issue of cisplatin resistance. Accordingly, the prepared Ru(II) complexes possess significant potential for development as highly effective and low-toxicity lung cancer therapeutic agents to overcome cisplatin resistance.

KEAP1-mutant atypical meningioma: illustrative case

BACKGROUND

While genetic testing of tumors is commonly used to inform the selection of systemic therapies, there is limited evidence for the application of radiotherapy for brain cancer. Recent studies have shown that Kelch-like ECH-associated protein 1 (KEAP1), a key regulator of cellular responses to oxidative and electrophilic stress, is associated with radioresistance in multiple cancer types. Several studies have reported the clinical significance of KEAP1 mutation in brain metastasis; however, the effect of KEAP1 mutations on radioresponse in meningioma has never been reported.

OBSERVATIONS

The authors present the case of a 40-year-old female with a KEAP1 mutation-positive atypical meningioma that was initially treated with resection followed by intensity-modulated radiation therapy (IMRT). Recurrence was observed at 15 months, requiring reoperation and adjuvant stereotactic radiosurgery (SRS). An excellent treatment response was observed at 7 months post-SRS with an improvement in reported symptoms, although bevacizumab was required for the resolution of radiation necrosis observed 2 months post-SRS.

LESSONS

To the authors' knowledge, this is the first report of KEAP1-mutant meningioma, including its clinical course after comprehensive management. Notably, treatment included multimodal radiotherapy with IMRT followed by SRS. SRS led to an excellent treatment response at the 7-month follow-up. However, radiation necrosis developed after both radiotherapy treatments, suggesting that radiological modification can be beneficial in patients with KEAP1 mutations. https://thejns.org/doi/10.3171/CASE24387.

Dual role of Nrf2 signaling in hepatocellular carcinoma: promoting development, immune evasion, and therapeutic challenges

Hepatocellular carcinoma (HCC) is the predominant form of liver cancer and ranks as the third leading cause of cancer-related mortality globally. The liver performs a wide range of tasks and is the primary organ responsible for metabolizing harmful substances and foreign compounds. Oxidative stress has a crucial role in growth and improvement of hepatocellular carcinoma (HCC). Nuclear factor erythroid 2 (1)-related factor 2 (Nrf2) is an element that regulates transcription located in the cytoplasm. It controls the balance of redox reactions by stimulating the expression of many genes that depend on antioxidant response elements. Nrf2 has contrasting functions in the normal, healthy liver and HCC. In the normal liver, Nrf2 provides advantageous benefits, while in HCC it promotes harmful effects that support the growth and survival of HCC. Continuous activation of Nrf2 has been detected in HCC and promotes its advancement and aggressiveness. In addition, Activation of Nrf2 may lead to immune evasion, weakening the immune cells' ability to attack tumors and thereby promoting tumor development. Furthermore, chemoresistance in HCC, which is considered a form of stress response to chemotherapy medications, significantly impedes the effectiveness of HCC treatment. Stress management is typically accomplished by activating specific signal pathways and chemical variables. One important element in the creation of chemoresistance in HCC is nuclear factor-E2-related factor 2 (Nrf2). Nrf2 is a transcription factor that regulates the activation and production of a group of genes that encode proteins responsible for protecting cells from damage. This occurs through the Nrf2/ARE pathway, which is a crucial mechanism for combating oxidative stress within cells.

Nrf2 as a regulator of energy metabolism and mitochondrial function

Nuclear factor erythroid-2-related factor 2 (Nrf2) is essential for the control of cellular redox homeostasis. When activated, Nrf2 elicits cytoprotective effects through the expression of several genes encoding antioxidant and detoxifying enzymes. Nrf2 can also improve antioxidant defense via the pentose phosphate pathway by increasing NADPH availability to regenerate glutathione. Microarray and genome-wide localization analyses have identified many Nrf2 target genes beyond those linked to its redox-regulatory capacity. Nrf2 regulates several intermediary metabolic pathways and is involved in cancer cell metabolic reprogramming, contributing to malignant phenotypes. Nrf2 also modulates substrate utilization for mitochondrial respiration. Here we review the experimental evidence supporting the essential role of Nrf2 in the regulation of energy metabolism and mitochondrial function.

Transcriptional Dynamics of NRF2 Overexpression and KEAP1-NRF2 Inhibitors in Human Cell Line and Primary Lung Cells

Oxidative stress in the human lung is caused by both internal (e.g., inflammation) and external stressors (smoking, pollution, and infection) to drive pathology in a number of lung diseases. Cellular damage caused by oxidative damage is reversed by several pathways, one of which is the antioxidant response. This response is regulated by the transcriptional factor NRF2, which has the ability to regulate the transcription of more than 250 genes. In disease, this balance is overwhelmed, and the cells are unable to return to homeostasis. Several pharmacological approaches aim to improve the antioxidant capacity by inhibiting the interaction of NRF2 with its key cytosolic inhibitor, KEAP1. Here, we evaluate an alternative approach by overexpressing NRF2 from chemically modified RNAs (cmRNAs). Our results demonstrate successful expression of functional NRF2 protein in human cell lines and primary cells. We establish a kinetic transcriptomic profile to compare antioxidant response gene expression after treatment of primary human bronchial epithelial cells with either KEAP1 inhibitors or cmRNAs. The key gene signature is then applied to primary human lung fibroblasts and alveolar macrophages to uncover transcriptional preferences in each cell system. This study provides a foundation for the understanding of NRF2 dynamics in the human lung and provides initial evidence of alternative ways for pharmacological interference.

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

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

Unraveling the Role of Reactive Oxygen Species in T Lymphocyte Signaling

Reactive oxygen species (ROS) are central to inter- and intracellular signaling. Their localized and transient effects are due to their short half-life, especially when generated in controlled amounts. Upon T cell receptor (TCR) activation, regulated ROS signaling is primarily initiated by complexes I and III of the electron transport chain (ETC). Subsequent ROS production triggers the activation of nicotinamide adenine dinucleotide phosphate oxidase 2 (NADPH oxidase 2), prolonging the oxidative signal. This signal then engages kinase signaling cascades such as the mitogen-activated protein kinase (MAPK) pathway and increases the activity of REDOX-sensitive transcription factors such as nuclear factor-kappa B (NF-κB) and activator protein-1 (AP-1). To limit ROS overproduction and prevent oxidative stress, nuclear factor erythroid 2-related factor 2 (Nrf2) and antioxidant proteins such as superoxide dismutases (SODs) finely regulate signal intensity and are capable of terminating the oxidative signal when needed. Thus, oxidative signals, such as T cell activation, are well-controlled and critical for cellular communication.

Nrf-2 as a novel target in radiation induced lung injury

Radiation-induced lung injury (RILI) is a common and fatal complication of chest radiotherapy. The underlying mechanisms include radiation-induced oxidative stress caused by damage to the deoxyribonucleic acid (DNA) and production of reactive oxygen species (ROS), resulting in apoptosis of lung and endothelial cells and recruitment of inflammatory cells and myofibroblasts expressing NADPH oxidase to the site of injury, which in turn contribute to oxidative stress and cytokine production. Nuclear factor erythroid 2-related factor 2 (Nrf-2) is a vital transcription factor that regulates oxidative stress and inhibits inflammation. Studies have shown that Nrf-2 protects against radiation-induced lung inflammation and fibrosis. This review discusses the protective role of Nrf-2 in RILI and its possible mechanisms.

Differential squamous cell fates elicited by NRF2 gain of function versus KEAP1 loss of function

Clinical evidence has revealed that high-level activation of NRF2 caused by somatic mutations in NRF2 (NFE2L2) is frequently detected in esophageal squamous cell carcinoma (ESCC), whereas that caused by somatic mutations in KEAP1, a negative regulator of NRF2, is not. Here, we aspire to generate a mouse model of NRF2-activated ESCC using the cancer-derived NRF2L30F mutation and cancer driver mutant TRP53R172H. Concomitant expression of NRF2L30F and TRP53R172H results in formation of NRF2-activated ESCC-like lesions. In contrast, while squamous-cell-specific deletion of KEAP1 induces similar NRF2 hyperactivation, the loss of KEAP1 combined with expression of TRP53R172H does not elicit the formation of ESCC-like lesions. Instead, KEAP1-deleted cells disappear from the esophageal epithelium over time. These findings demonstrate that, while cellular NRF2 levels are similarly induced, NRF2 gain of function and KEAP1 loss of function elicits distinct fates of squamous cells. The NRF2L30F mutant mouse model developed here will be instrumental in elucidating the mechanistic basis leading to NRF2-activated ESCC.

Natural products as non-covalent and covalent modulators of the KEAP1/NRF2 pathway exerting antioxidant effects

By controlling several antioxidant and detoxifying genes at the transcriptional level, including NAD(P)H quinone oxidoreductase 1 (NQO1), multidrug resistance-associated proteins (MRPs), UDP-glucuronosyltransferase (UGT), glutamate-cysteine ligase catalytic (GCLC) and modifier (GCLM) subunits, glutathione S-transferase (GST), sulfiredoxin1 (SRXN1), and heme-oxygenase-1 (HMOX1), the KEAP1/NRF2 pathway plays a crucial role in the oxidative stress response. Accordingly, the discovery of modulators of this pathway, activating cellular signaling through NRF2, and targeting the antioxidant response element (ARE) genes is pivotal for the development of effective antioxidant agents. In this context, natural products could represent promising drug candidates for supplementation to provide antioxidant capacity to human cells. In recent decades, by coupling in silico and experimental methods, several natural products have been characterized to exert antioxidant effects by targeting the KEAP1/NRF2 pathway. In this review article, we analyze several natural products that were investigated experimentally and in silico for their ability to modulate KEAP1/NRF2 by non-covalent and covalent mechanisms. These latter represent the two main sections of this article. For each class of inhibitors, we reviewed their antioxidant effects and potential therapeutic applications, and where possible, we analyzed the structure-activity relationship (SAR). Moreover, the main computational techniques used for the most promising identified compounds are detailed in this survey, providing an updated view on the development of natural products as antioxidant agents.

Impact of LKB1 status on radiation outcome in patients with stage III non-small-cell lung cancer

Preclinical studies suggest that loss of LKB1 expression renders cancer cells less responsive to radiation partly through NRF2-mediated upregulation of antioxidant enzymes protecting against radiation-induced DNA damage. Here we investigated the association of an alteration in this pathway with radio-resistance in lung cancer patients. Patients with locally advanced non-small cell lung cancer (LA-NSCLC) who were treated with chemoradiotherapy (CRT) and analyzed for LKB1 expression using semiquantitative immunohistochemistry. Clinical characteristics and expression of LKB1 were analyzed for association with radiotherapy outcomes. We analyzed 74 available tumor specimens from 178 patients. After a median follow-up of 40.7 months, 2-year cumulative incidence of locoregional recurrence (LRR) in patients who had LKB1Low expression was significantly higher than those with LKB1High expression (68.8% vs. 31.3%, P = 0.0001). LKB1Low expression was found significantly associated with a higher incidence of distant metastases (DM) (P = 0.0008), shorter disease-free survival (DFS) (P = 0.006), and worse overall survival (OS) (P = 0.02) compared to LKB1High expression. Moreover, patients with LKB1Low expression showed a significantly higher 2-year cumulative incidence of LRR (77.6% vs. 21%; P = 0.02), higher DM recurrence (P = 0.002), and shorter OS (P < 0.0001) compared with the EGFR-mutant group. For all patients with LKB1Low who had LRR, these recurrences occurred within the field of radiation, in contrast to those with LKB1High expression having both in-field, marginal, and out-of-field failures. LKB1 expression may serve as a potential biomarker for poor outcomes after receiving radiation in LA-NSCLC patients. Further studies to confirm the association and application are warranted.

Unique and overlapping roles of NRF2 and NRF1 in transcriptional regulation

Transcription is regulated by specific transcription factors that mediate signaling in response to extrinsic and intrinsic stimuli such as nutrients, hormones, and oxidative stresses. Many transcription factors are grouped based on their highly conserved DNA binding domains. Consequently, transcription factors within the same family often exhibit functional redundancy and compensation. NRF2 (NFE2L2) and NRF1 (NFE2L1) belong to the CNC family transcription factors, which are responsible for various stress responses. Although their DNA binding properties are strikingly similar, NRF2 and NRF1 are recognized to play distinct roles in a cell by mediating responses to oxidative stress and proteotoxic stress, respectively. In this review, we here overview the distinct and shared roles of NRF2 and NRF1 in the transcriptional regulation of target genes, with a particular focus on the nuclear protein binding partners associated with each factor.

Effects of Inhibition of IKK Kinase Phosphorylation On the Cellular Defence System and HSP90 Activity

The present study was conceived to examine the effects of inhibition of BMS-345541 mediated IKK kinase phosphorylation on the cellular defence system as well as on anti-inflammatory response and HSP90 activity. The analysis was conducted in A549 cell line, since such cells carry a homozygous Keap1 mutation (G333C) that alters its interaction with Nrf2. Recent data have highlighted that Keap1, HSP90 protein and IKK kinase interact reciprocally and particularly Keap1 protein is involved in HSP90 and anti-oxidative pathway regulation. The activities of COX2 and HO1 were investigated by real time and immunoblot analysis along with the synthesis and activity of inducible forms of heat shock protein HSP90. Pre-treatment with IKK kinase inhibitor proved to be a protective means to lower the activity of inflammatory cascade, so preventing the formation of excessive amounts of pro-inflammatory molecules. The inhibitor of IKK kinase BMS-345541 was added to cultured A549 cells before the Escherichia coli lipopolysaccharide (LPS) addition. The viability of the cells was determined after 1-24 h incubation with BMS-345541 at concentrations ranging from 1,25-5 µM. It was found that 1 µM concentration does not significantly affected cell viability (data not shown). As a result, the treatment with 1 μM of BMS-345541 induces the inhibition of IKK phosphorylation. In the A549 cells treated with BMS-345541 and LPS, COX2 activity is not induced: mRNA and protein levels have not increased, while there is an increase in the level of HSP90, HO1 proteins and mRNA. The results suggest that the IKK inhibition is effective in the reduction of the inflammatory response thanks to mechanisms involving both the heat shock cellular defense system and the antioxidative pathway.

Potential inhibitors of RPS6KB2 and NRF2 in head and neck squamous cell carcinoma

Among the major altered pathways in head and neck squamous cell carcinoma, AKT/mTORC1/S6K and NRF2/KEAP1 pathway are quite significant. The overexpression and overstimulation of proteins from both these pathways makes them the promising candidates in cancer therapeutics. Inhibiting mTOR has been in research from past several decades but the tumour heterogeneity, and upregulation of several compensatory feed-back mechanisms, encourages to explore other downstream targets for inhibiting the pathway. One such downstream effectors of mTOR is S6K2. It is reported to be overexpressed in cancers such as head and neck cancer, breast cancer and prostate cancer. In case of NRF2/KEAP1 pathway, nuclear factor erythroid 2-related factor 2 (NFE2L2 or NRF2) is overexpressed in ∼90% of head and neck squamous cell carcinoma (HNSCC) cases. It associates with poor survival rate and therapeutic resistance in HNSCC treatment. NRF2 pathway is the primary antioxidant pathway in the cell which also serves pro-tumorigenic functions, such as repression of apoptosis, cell proliferation support and chemoresistance. The aim of this work was to explore S6K2 and NRF2 and identify novel and potential inhibitors against them for treating head and neck squamous cell carcinoma. Since the crystal structure of S6K2 was not available at the time of this study, we modelled its structure using homology modelling and performed high throughput screening, molecular dynamics simulations, free energy calculations and protein-ligand interaction studies to identify the inhibitors. We identified natural compounds Crocin and Gypenoside XVII against S6K2 and Chebulinic acid and Sennoside A against NRF2. This study provides a significant in-depth understanding of the two studied pathways and therefore can be used in the development of potential therapeutics against HNSCC.Communicated by Ramaswamy H. Sarma.

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

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

Regulation of antioxidants in cancer

Scientists in this field often joke, "If you don't have a mechanism, say it's ROS." Seemingly connected to every biological process ever described, reactive oxygen species (ROS) have numerous pleiotropic roles in physiology and disease. In some contexts, ROS act as secondary messengers, controlling a variety of signaling cascades. In other scenarios, they initiate damage to macromolecules. Finally, in their worst form, ROS are deadly to cells and surrounding tissues. A set of molecules with detoxifying abilities, termed antioxidants, is the direct counterpart to ROS. Notably, antioxidants exist in the public domain, touted as a "cure-all" for diseases. Research has disproved many of these claims and, in some cases, shown the opposite. Of all the diseases, cancer stands out in its paradoxical relationship with antioxidants. Although the field has made numerous strides in understanding the roles of antioxidants in cancer, many questions remain.

The Multifaceted Roles of NRF2 in Cancer: Friend or Foe?

Physiological concentrations of reactive oxygen species (ROS) play vital roles in various normal cellular processes, whereas excessive ROS generation is central to disease pathogenesis. The nuclear factor erythroid 2-related factor 2 (NRF2) is a critical transcription factor that regulates the cellular antioxidant systems in response to oxidative stress by governing the expression of genes encoding antioxidant enzymes that shield cells from diverse oxidative alterations. NRF2 and its negative regulator Kelch-like ECH-associated protein 1 (KEAP1) have been the focus of numerous investigations in elucidating whether NRF2 suppresses tumor promotion or conversely exerts pro-oncogenic effects. NRF2 has been found to participate in various pathological processes, including dysregulated cell proliferation, metabolic remodeling, and resistance to apoptosis. Herein, this review article will examine the intriguing role of phase separation in activating the NRF2 transcriptional activity and explore the NRF2 dual impacts on tumor immunology, cancer stem cells, metastasis, and long non-coding RNAs (LncRNAs). Taken together, this review aims to discuss the NRF2 multifaceted roles in both cancer prevention and promotion while also addressing the advantages, disadvantages, and limitations associated with modulating NRF2 therapeutically in cancer treatment.

Genetic Factors and MicroRNAs in the Development of Gallbladder Cancer: The Prospective Clinical Targets

Gallbladder cancer (GBC) is an uncommon condition in which malignant (cancer) cells are detected in gallbladder tissue. Cancer is often triggered when normal cells turn malignant and begin to spread. Cancer can also be caused by genetic anomalies that result in uncontrolled cell proliferation and tumor development. MicroRNAs (also known as miRNAs or miRs) are a group of small, endogenous, non-coding RNAs of 19-23 nucleotides in length, which play a key role in post-transcriptional gene regulation. These miRNAs serve as negative gene regulators by supervising target genes and regulating biological processes, including cell proliferation, migration, invasion, and apoptosis. Cancer development and progression relate to aberrant miRNA expression. This review demonstrated the implication of various genetic factors and microRNAs in developing and regulating GBC. This suggests the potential of genes and RNAs as the diagnostic, prognostic, and therapeutic targets in gallbladder cancer.

Nrf2, A Target for Precision Oncology in Cancer Prognosis and Treatment

Activating nuclear factor-erythroid 2-related factor (Nrf2), a master regulator of redox homeostasis, has been shown to suppress initiation of carcinogenesis in normal cells. However, this transcription factor has recently been reported to promote proliferation of some transformed or cancerous cells. In tumor cells, Nrf2 is prone to mutations that result in stabilization and concurrent accumulation of its protein product. A hyperactivated mutant form of Nrf2 could support the cancer cells for enhanced proliferation, invasiveness, and resistance to chemotherapeutic agents and radiotherapy, which are associated with a poor clinical outcome. Hence understanding mutations in Nrf2 would have a significant impact on the prognosis and treatment of cancer in the era of precision medicine. This perspective would provide an insight into the genetic alterations in Nrf2 and suggest the application of small molecules, RNAi, and genome editing technologies, particularly CRISR-Cas9, in therapeutic intervention of cancer in the context of the involvement of Nrf2 mutations.

Proximity proteomic analysis of the NRF family reveals the Parkinson's disease protein ZNF746/PARIS as a co-complexed repressor of NRF2

The nuclear factor erythroid 2-related factor 2 (NRF2) transcription factor activates cytoprotective and metabolic gene expression in response to various electrophilic stressors. Constitutive NRF2 activity promotes cancer progression, whereas decreased NRF2 function contributes to neurodegenerative diseases. We used proximity proteomic analysis to define protein networks for NRF2 and its family members NRF1, NRF3, and the NRF2 heterodimer MAFG. A functional screen of co-complexed proteins revealed previously uncharacterized regulators of NRF2 transcriptional activity. We found that ZNF746 (also known as PARIS), a zinc finger transcription factor implicated in Parkinson's disease, physically associated with NRF2 and MAFG, resulting in suppression of NRF2-driven transcription. ZNF746 overexpression increased oxidative stress and apoptosis in a neuronal cell model of Parkinson's disease, phenotypes that were reversed by chemical and genetic hyperactivation of NRF2. This study presents a functionally annotated proximity network for NRF2 and suggests a link between ZNF746 overexpression in Parkinson's disease and inhibition of NRF2-driven neuroprotection.

Comparative analysis of the molecular and physiological consequences of constitutive SKN-1 activation

Molecular homeostats play essential roles across all levels of biological organization to ensure a return to normal function after responding to abnormal internal and environmental events. SKN-1 is an evolutionarily conserved cytoprotective transcription factor that is integral for the maintenance of cellular homeostasis upon exposure to a variety of stress conditions. Despite the essentiality of turning on SKN-1/NRF2 in response to exogenous and endogenous stress, animals with chronic activation of SKN-1 display premature loss of health with age, and ultimately, diminished lifespan. Previous genetic models of constitutive SKN-1 activation include gain-of-function alleles of skn-1 and loss-of-function alleles of wdr-23 that impede the turnover of SKN-1 by the ubiquitin proteasome. Here, we define a novel gain-of-function mutation in the xrep-4 locus that results in constitutive activation of SKN-1 in the absence of stress. Although each of these genetic mutations results in continuously unregulated transcriptional output from SKN-1, the physiological consequences of each model on development, stress resistance, reproduction, lipid homeostasis, and lifespan are distinct. Here, we provide a comprehensive assessment of the differential healthspan impacts across multiple models of constitutive SKN-1 activation. Although our results reveal the universal need to reign in the uncontrolled activity of cytoprotective transcription factors, we also define the unique signatures of each model of constitutive SKN-1 activation, which provides innovative solutions for the design of molecular "off-switches" of unregulated transcriptional homeostats.

NRF2/HO-1 axis, BIRC5, and TP53 expression in ESCC and its correlation with clinical pathological characteristics and prognosis

BACKGROUND

Many types of cancer exhibit high nuclear factor erythroid 2-related factor 2 (NRF2), which is effective in resisting drugs and radiation. However, the role of NRF2 gene expression in predicting the prognosis of esophageal squamous cell carcinoma (ESCC) remains unclear.

METHODS

The association between NRF2, heme oxygenase-1 (HO-1), baculovirus IAP repeat 5 (BIRC5), P53 gene expression levels and their relationship to immune-infiltrating cells were assessed using the Cancer Genome Atlas dataset, the Human Protein Atlas and the TISDB database. The expression of NRF2, HO-1, BIRC5, and TP53 in 118 ESCC patients was detected by immunohistochemistry, and the relationship between their expression level and clinicopathological parameters and prognosis was analyzed.

RESULTS

In ESCC, NRF2 overexpression was significantly associated with Han ethnicity, lymph node metastasis, and distant metastasis. HO-1 overexpression was significantly associated with differentiation, advanced clinical staging, lymph node metastasis, nerve invasion, and distant metastasis. BIRC5 overexpression was significantly associated with Han ethnicity and lymph node metastasis. TP53 overexpression was significantly associated with Han ethnicity and T staging. The NRF2/HO-1 axis expression was positively correlated with BIRC5 and TP53. Kaplan-Meier and multivariate Cox regression analysis showed that NRF2, BIRC5, and TP53 genes co-expression was an independent prognostic risk factor. TISIDB dataset analysis showed that immune-infiltrating cells were significantly negatively correlated with NRF2 and BIRC5.

CONCLUSION

NRF2, BIRC5, and TP53 axis gene expressions are predictors of poor prognosis for ESCC. The overexpression of the NRF2/HO-1/BIRC5 axis may not be related to immune-infiltrating cells.

KEAP1 mutation in lung adenocarcinoma promotes immune evasion and immunotherapy resistance

Lung cancer treatment has benefited greatly through advancements in immunotherapies. However, immunotherapy often fails in patients with specific mutations like KEAP1, which are frequently found in lung adenocarcinoma. We established an antigenic lung cancer model and used it to explore how Keap1 mutations remodel the tumor immune microenvironment. Using single-cell technology and depletion studies, we demonstrate that Keap1-mutant tumors diminish dendritic cell and T cell responses driving immunotherapy resistance. This observation was corroborated in patient samples. CRISPR-Cas9-mediated gene targeting revealed that hyperactivation of the NRF2 antioxidant pathway is responsible for diminished immune responses in Keap1-mutant tumors. Importantly, we demonstrate that combining glutaminase inhibition with immune checkpoint blockade can reverse immunosuppression, making Keap1-mutant tumors susceptible to immunotherapy. Our study provides new insight into the role of KEAP1 mutations in immune evasion, paving the way for novel immune-based therapeutic strategies for KEAP1-mutant cancers.

Influence of intermittent fasting on autophagy in the liver

Studies have found that intermittent fasting (IF) can prevent diabetes, cancer, heart disease, and neuropathy, while in humans it has helped to alleviate metabolic syndrome, asthma, rheumatoid arthritis, Alzheimer's disease, and many other disorders. IF involves a series of coordinated metabolic and hormonal changes to maintain the organism's metabolic balance and cellular homeostasis. More importantly, IF can activate hepatic autophagy, which is important for maintaining cellular homeostasis and energy balance, quality control, cell and tissue remodeling, and defense against extracellular damage and pathogens. IF affects hepatic autophagy through multiple interacting pathways and molecular mechanisms, including adenosine monophosphate (AMP)-activated protein kinase (AMPK), mammalian target of rapamycin (mTOR), silent mating-type information regulatory 2 homolog-1 (SIRT1), peroxisomal proliferator-activated receptor alpha (PPARα) and farnesoid X receptor (FXR), as well as signaling pathways and molecular mechanisms such as glucagon and fibroblast growth factor 21 (FGF21). These pathways can stimulate the pro-inflammatory cytokines interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α), play a cytoprotective role, downregulate the expression of aging-related molecules, and prevent the development of steatosis-associated liver tumors. By influencing the metabolism of energy and oxygen radicals as well as cellular stress response systems, IF protects hepatocytes from genetic and environmental factors. By activating hepatic autophagy, IF has a potential role in treating a variety of liver diseases, including non-alcoholic fatty liver disease, drug-induced liver injury, viral hepatitis, hepatic fibrosis, and hepatocellular carcinoma. A better understanding of the effects of IF on liver autophagy may lead to new approaches for the prevention and treatment of liver disease.

Disruption of the Keap1-mTORC2 axis by cancer-derived Keap1/mLST8 mutations leads to oncogenic mTORC2-AKT activation

The mechanistic target of the rapamycin (mTOR) pathway, which participates in the regulation of cellular growth and metabolism, is aberrantly regulated in various cancer types. The mTOR complex 2 (mTORC2), which consists of the core components mTOR, Rictor, mSin1, and mLST8, primarily responds to growth signals. However, the coordination between mTORC2 assembly and activity remains poorly understood. Keap1, a major sensor of oxidative stress in cells, functions as a substrate adaptor for Cullin 3-RING E3 ubiquitin ligase (CRL3) to promote proteasomal degradation of NF-E2-related factor 2 (NRF2), which is a transcription factor that protects cells against oxidative and electrophilic stress. In the present study, we demonstrate that Keap1 binds to mLST8 via a conserved ETGE motif. The CRL3Keap1 ubiquitin ligase complex promotes non-degradative ubiquitination of mLST8, thus reducing mTORC2 complex integrity and mTORC2-AKT activation. However, this effect can be prevented by oxidative/electrophilic stresses and growth factor signaling-induced reactive oxygen species (ROS) burst. Cancer-derived Keap1 or mLST8 mutations disrupt the Keap1-mLST8 interaction and allow mLST8 to evade Keap1-mediated ubiquitination, thereby enhancing mTORC2-AKT activation and promoting cell malignancy and remodeling cell metabolism. Our findings provide new insights into the molecular mechanisms of Keap1/mLST8 mutation-driven tumorigenesis by promoting mTORC2-AKT activation, which is independent of the canonical NRF2 pathway.

Targeted Proteomic Quantitation of NRF2 Signaling and Predictive Biomarkers in HNSCC

The NFE2L2 (NRF2) oncogene and transcription factor drives a gene expression program that promotes cancer progression, metabolic reprogramming, immune evasion, and chemoradiation resistance. Patient stratification by NRF2 activity may guide treatment decisions to improve outcome. Here, we developed a mass spectrometry-based targeted proteomics assay based on internal standard-triggered parallel reaction monitoring to quantify 69 NRF2 pathway components and targets, as well as 21 proteins of broad clinical significance in head and neck squamous cell carcinoma (HNSCC). We improved an existing internal standard-triggered parallel reaction monitoring acquisition algorithm, called SureQuant, to increase throughput, sensitivity, and precision. Testing the optimized platform on 27 lung and upper aerodigestive cancer cell models revealed 35 NRF2 responsive proteins. In formalin-fixed paraffin-embedded HNSCCs, NRF2 signaling intensity positively correlated with NRF2-activating mutations and with SOX2 protein expression. Protein markers of T-cell infiltration correlated positively with one another and with human papilloma virus infection status. CDKN2A (p16) protein expression positively correlated with the human papilloma virus oncogenic E7 protein and confirmed the presence of translationally active virus. This work establishes a clinically actionable HNSCC protein biomarker assay capable of quantifying over 600 peptides from frozen or formalin-fixed paraffin-embedded archived tissues in under 90 min.

A NRF2-induced secretory phenotype activates immune surveillance to remove irreparably damaged cells

While it is well established that the KEAP1-NRF2 pathway regulates the main inducible cellular response to oxidative stress, this cytoprotective function of NRF2 could become deleterious to the host if it confers survival onto irreparably damaged cells. In this regard, we have found that in diseased states, NRF2 promotes the transcriptional activation of a specific subset of the senescence-associated secretory phenotype (SASP) gene program, which we have named the NRF2-induced secretory phenotype (NISP). In two models of hepatic disease using Pten::Keap1 and Keap1::Atg7 double knockout mice, we found that the NISP functions in the liver to recruit CCR2 expressing monocytes, which function as immune system effector cells to directly remove the damaged cells. Through activation of this immune surveillance pathway, in non-transformed cells, NRF2 functions as a tumour suppressor to mitigate the long-term survival of damaged cells which otherwise would be detrimental for host survival. This pathway represents the final stage of the oxidative stress response, as it allows cells to be safely removed if the macromolecular damage caused by the original stressor is so extensive that it is beyond the repair capacity of the cell.

The untapped potential of targeting NRF2 in neurodegenerative disease

Since its initial discovery almost three decades ago, the transcription factor nuclear factor erythroid 2-related factor 2 (NRF2) has been shown to regulate a host of downstream transcriptional responses and play a critical role in preventing or promoting disease progression depending on the context. Critically, while the importance of proper nuclear factor erythroid 2-related factor 2 function has been demonstrated across a variety of pathological settings, the ability to progress NRF2-targeted therapeutics to clinic has remained frustratingly elusive. This is particularly true in the case of age-related pathologies, where nuclear factor erythroid 2-related factor 2 is a well-established mitigator of many of the observed pathogenic effects, yet options to target this pathway remain limited. Along these lines, loss of nuclear factor erythroid 2-related factor 2 function has clearly been shown to enhance neuropathological outcomes, with enhancing nuclear factor erythroid 2-related factor 2 pathway activation to prevent neurodegenerative/neurological disease progression continuing to be an active area of interest. One critical obstacle in generating successful therapeutics for brain-related pathologies is the ability of the compound to cross the blood brain barrier (BBB), which has also hampered the implementation of several promising nuclear factor erythroid 2-related factor 2 inducers. Another limitation is that many nuclear factor erythroid 2-related factor 2 activators have undesirable off-target effects due to their electrophilic nature. Despite these constraints, the field has continued to evolve, and several viable means of targeting nuclear factor erythroid 2-related factor 2 in a neuropathological context have emerged. In this perspective, we will briefly discuss the key findings and promising therapeutic options that have been discovered to date, as well as highlight emerging areas of NRF2-neurodegeneration research that provide hope for successfully targeting this pathway in the future.

Ethnic differences in hepatocellular carcinoma prevalence and therapeutic outcomes

BACKGROUND

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death worldwide. The incidence of HCC is affected by genetic and non-genetic factors. Genetically, mutations in the genes, tumor protein P53 (TP53), catenin beta 1 (CTNNB1), AT-rich interaction domain 1A (ARIC1A), cyclin dependent kinase inhibitor 2A (CDKN2A), mannose 6-phosphate (M6P), smooth muscle action against decapentaplegic (SMAD2), retinoblastoma gene (RB1), cyclin D, antigen presenting cells (APC), AXIN1, and E-cadherin, have been shown to contribute to the occurrence of HCC. Non-genetic factors, including alcohol consumption, exposure to aflatoxin, age, gender, presence of hepatitis B (HBV), hepatitis C (HCV), and non-alcoholic fatty liver disease (NAFLD), increase the risk of HCC.

RECENT FINDINGS

The severity of the disease and its occurrence vary based on geographical location. Furthermore, men and minorities have been shown to be disproportionately affected by HCC, compared with women and non-minorities. Ethnicity has been reported to significantly affect tumorigenesis and clinical outcomes in patients diagnosed with HCC. Generally, differences in gene expression and/or the presence of comorbid medical diseases affect or influence the progression of HCC. Non-Caucasian HCC patients are significantly more likely to have poorer survival outcomes, compared to their Caucasian counterparts. Finally, there are a number of factors that contribute to the success rate of treatments for HCC.

CONCLUSION

Assessment and treatment of HCC must be consistent using evidence-based guidelines and standardized outcomes, as well as international clinical practice guidelines for global consensus. Standardizing the assessment approach and method will enable comparison and improvement of liver cancer research through collaboration between researchers, healthcare providers, and advocacy groups. In this review, we will focus on discussing epidemiological factors that result in deviations and changes in treatment approaches for HCC.

Alantolactone triggers oxeiptosis in human ovarian cancer cells via Nrf2 signaling pathway

Introduction

A growing body of evidence indicated that Alantolactone (ALT) promotes Reactive Oxygen Species (ROS) generation exclusively in cancer cells. Therefore, the aim of this study was to investigate the effect of ALT on the molecular mechanism of oxeiptosis, as a novel cell death pathway due to the high levels of intracellular ROS in ovarian cancer.

Methods

MTT assay was used to evaluate the effect of ALT on SKOV3 cell viability. mRNA and protein expression levels of Nrf2 (nuclear factor erythroid 2-related factor 2), KEAP1 (Kelch-like ECH-associated protein 1), PGAM5 (phosphoglycerate mutase family member 5), AIFM1 (Mitochondrial Apoptosis-Inducing Factor), Glutathione synthetase (GSS) and glutathione peroxidase (GPX) were analyzed by real time PCR and western blotting methods respectively.

Results

Our findings showed that ALT inhibits the proliferation of skov3 cells in a time and dose dependent manner and IC50 was 32 μM at 24h.A significant down-regulation of Nrf2, GSH and GPX mRNA levels was seen in skov3 cells incubated with 32 and 64 μM of ALT in comparison with control group, while, mRNA expression levels of PGAM5 and KEAP1 were increased.Western blot analysis showed that ALT significantly decreases protein levels of Nrf2 and increases PGAM5 and KEAP1.ALT dephosphorylated PS116-AIFM1 and total AIFM1 protein level was elevated.

Conclusion

Our results provided evidence that ALT could be a potential option for ovarian cancer treatment by ROS-mediated oxeiptosis.

Sequential Ubiquitination and Phosphorylation Epigenetics Reshaping by MG132-Loaded Fe-MOF Disarms Treatment Resistance to Repulse Metastatic Colorectal Cancer

Abnormal epigenetic regulation is identified to correlate with cancer progression and renders tumor refractory and resistant to reactive oxygen species (ROS)-based anti-tumor actions. To address it, a sequential ubiquitination and phosphorylation epigenetics modulation strategy is developed and exemplified by the well-established Fe-metal-organic framework (Fe-MOF)-based chemodynamic therapy (CDT) nanoplatforms that load the 26S proteasome inhibitor (i.e., MG132). The encapsulated MG132 can blockade 26S proteasome, terminate ubiquitination, and further inhibit transcription factor phosphorylation (e.g., NF-κB p65), which can boost pro-apoptotic or misfolded protein accumulations, disrupt tumor homeostasis, and down-regulate driving genes expression of metastatic colorectal cancer (mCRC). Contributed by them, Fe-MOF-unlocked CDT is magnified to considerably elevate ROS content for repulsing mCRC, especially after combining with macrophage membrane coating-enabled tropism accumulation. Systematic experiments reveal the mechanism and signaling pathway of such a sequential ubiquitination and phosphorylation epigenetics modulation and explain how it could blockade ubiquitination and phosphorylation to liberate the therapy resistance to ROS and activate NF-κB-related acute immune responses. This unprecedented sequential epigenetics modulation lays a solid foundation to magnify oxidative stress and can serve as a general method to enhance other ROS-based anti-tumor methods.

An antioxidant response element regulates the HIF1α axis in breast cancer cells

The redox sensitive transcription factor NRF2 is a central regulator of the transcriptional response to reactive oxygen species (ROS). NRF2 is widely recognized for its ROS-responsive upregulation of antioxidant genes that are essential for mitigating the damaging effects of oxidative stress. However, multiple genome-wide approaches have suggested that NRF2's regulatory reach extends well beyond the canonical antioxidant genes, with the potential to regulate many noncanonical target genes. Recent work from our lab and others suggests HIF1A, which encodes the hypoxia-responsive transcription factor HIF1α, is one such noncanonical NRF2 target. These studies found that NRF2 activity is associated with high HIF1A expression in multiple cellular contexts, HIF1A expression is partially dependent on NRF2, and there is a putative NRF2 binding site (antioxidant response element, or ARE) approximately 30 kilobases upstream of HIF1A. These findings all support a model in which HIF1A is a direct target of NRF2, but did not confirm the functional importance of the upstream ARE in HIF1A expression. Here we use CRISPR/Cas9 genome editing to mutate this ARE in its genomic context and test the impact on HIF1A expression. We find that mutation of this ARE in a breast cancer cell line (MDA-MB-231) eliminates NRF2 binding and decreases HIF1A expression at the transcript and protein levels, and disrupts HIF1α target genes as well as phenotypes driven by these HIF1α targets. Taken together, these results indicate that this NRF2 targeted ARE plays an important role in the expression of HIF1A and activity of the HIF1α axis in MDA-MB-231 cells.

The mechanistic insights of the antioxidant Keap1-Nrf2 pathway in oncogenesis: a deadly scenario

The Nuclear factor erythroid 2-related factor 2 (Nrf2) protein has garnered significant interest due to its crucial function in safeguarding cells and tissues. The Nrf2 protein is crucial in preserving tissue integrity by safeguarding cells against metabolic, xenobiotic and oxidative stress. Due to its various functions, Nrf2 is a potential pharmacological target for reducing the incidence of diseases such as cancer. However, mutations in Keap1-Nrf2 are not consistently favored in all types of cancer. Instead, they seem to interact with specific driver mutations of tumors and their respective tissue origins. The Kelch-like ECH-associated protein 1 (Keap1)-Nrf2 pathway mutations are a powerful cancer adaptation that utilizes inherent cytoprotective pathways, encompassing nutrient metabolism and ROS regulation. The augmentation of Nrf2 activity elicits significant alterations in the characteristics of neoplastic cells, such as resistance to radiotherapy and chemotherapy, safeguarding against apoptosis, heightened invasiveness, hindered senescence, impaired autophagy and increased angiogenesis. The altered activity of Nrf2 can arise from diverse genetic and epigenetic modifications that instantly impact Nrf2 regulation. The present study aims to showcase the correlation between the Keap1-Nrf2 pathway and the progression of cancers, emphasizing genetic mutations, metabolic processes, immune regulation, and potential therapeutic strategies. This article delves into the intricacies of Nrf2 pathway anomalies in cancer, the potential ramifications of uncontrolled Nrf2 activity, and therapeutic interventions to modulate the Keap1-Nrf2 pathway.

Association between insulin and Nrf2 signalling pathway in Alzheimer's disease: A molecular landscape

Insulin, a well-known hormone, has been implicated as a regulator of blood glucose levels for almost a century now. Over the past few decades, the non-glycemic actions of insulin i.e. neuronal growth and proliferation have been extensively studied. In 2005, Dr. Suzanne de La Monte and her team reported that insulin might be involved in the pathogenesis of Alzheimer's Disease (AD) and thus coined a term "Type-3 diabetes" This hypothesis was supported by several subsequent studies. The nuclear factor erythroid 2- related factor 2 (Nrf2) triggers a cascade of events under the regulation of distinct mechanisms including protein stability, phosphorylation and nuclear cytoplasmic shuttling, finally leading to the protection against oxidative damage. The Nrf2 pathway has been investigated extensively in relevance to neurodegenerative disorders, particularly AD. Many studies have indicated a strong correlation between insulin and Nrf2 signalling pathways both in the periphery and the brainbut merely few of them have focused on elucidating their inter-connective role in AD. The present review emphasizes key molecular pathways that correlate the role of insulin with Nrf2 during AD. The review has also identified key unexplored areas that could be investigated in future to further establish the insulin and Nrf2 influence in AD.