Oncogene-induced Nrf2 transcription promotes ROS detoxification and tumorigenesis

Synergistic effects of BET inhibitors and ferroptosis inducers via targeted inhibition of the BRD4/c-Myc/NRF2 pathway in AML

In acute myeloid leukemia (AML), high expression of BRD4 is associated with poor prognosis. BET inhibitors that mainly inhibit BRD4 can induce AML cell death, but some AML cells are insensitive to BET inhibitors. We found that BET inhibitors could promote the up-regulation of the ferroptosis signaling pathway in AML. In this study, we intend to investigate the synergistic effects of BET inhibitors with ferroptosis inducers in AML cells. The combination of BET inhibitors with ferroptosis inducers (RSL3, FIN56, and Erastin) markedly reduced AML cell viability and increased cell death, as demonstrated by CCK-8 assays and flow cytometry analysis across multiple AML cell lines and primary AML patient samples. Moreover, BET inhibitors combined with ferroptosis inducers elevated the lipid reactive oxygen species (ROS) levels, indicating heightened lipid peroxidation, a hallmark of ferroptosis. Mechanistically, BET inhibitor and ferroptosis inducer co-targeted the BRD4/c-Myc/NRF2 axis, leading to downregulation of NRF2, key regulators of AML cell survival and oxidative stress resistance. NRF2 knockdown amplified the anti-AML effect of this combined treatment, whereas NRF2 overexpression negated this synergy, highlighting its critical role in mediating ferroptosis resistance. Finally, survival analyses of AML patients from the TCGA and GSE71014 datasets revealed that elevated expression of BRD4, NRF2, and its downstream target GPX4, an essential ferroptosis regulator, correlated with poor overall survival, highlighting the clinical relevance of our findings. In all, combining BET inhibition with ferroptosis induction could enhance anti-leukemia effect and represent a novel therapeutic strategy for targeting AML cells.

Urolithins: Emerging natural compound targeting castration-resistant prostate cancer (CRPC)

Castration-resistant prostate cancer (CRPC) presents a significant challenge due to its resistance to conventional androgen deprivation therapies. Urolithins, bioactive metabolites derived from ellagitannins, have recently emerged as promising therapeutic agents for CRPC. Urolithins not only inhibit androgen receptor (AR) signaling, a crucial factor in the progression of CRPC, but also play a key role in regulating oxidative stress by their antioxidant properties, thereby inhibiting increased reactive oxygen species, a common feature of the aggressive nature of CRPC. Research has shown that urolithins induce apoptosis and diminish pro-survival signaling, leading to tumor inhibition. This review delves into the intricate mechanisms through which urolithins exert their therapeutic effects, focusing on both AR-dependent and AR-independent pathways. It also explores the exciting potential of combining urolithins with androgen ablation therapy, opening new avenues for CRPC treatment.

Molecular Targets of Oxidative Stress: Focus on Nuclear Factor Erythroid 2-Related Factor 2 Function in Leukemia and Other Cancers

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that plays a central role in regulating cellular responses to oxidative stress. It governs the expression of a broad range of genes involved in antioxidant defense, detoxification, metabolism, and other cytoprotective pathways. In normal cells, the transient activation of Nrf2 serves as a protective mechanism to maintain redox homeostasis. However, the persistent or aberrant activation of Nrf2 in cancer cells has been implicated in tumor progression, metabolic reprogramming, and resistance to chemotherapy and radiotherapy. These dual roles underscore the complexity of Nrf2 signaling and its potential as a therapeutic target. A deeper understanding of Nrf2 regulation in both normal and malignant contexts is essential for the development of effective Nrf2-targeted therapies. This review provides a comprehensive overview of Nrf2 regulation and function, highlighting its unique features in cancer biology, particularly its role in metabolic adaptation and drug resistance. Special attention is given to the current knowledge of Nrf2's involvement in leukemia and emerging strategies for its therapeutic modulation.

NRF2 supports non-small cell lung cancer growth independently of CBP/p300-enhanced glutathione synthesis

Nuclear factor erythroid 2-related factor 2 (NRF2) is a stress responsive transcription factor that is mutationally activated in a subset (~25%) of clinically-aggressive non-small cell lung cancers (NSCLC). Mechanistic insight into drivers of the NRF2 dependency remains poorly understood. Here, we defined a novel NRF2 target gene set linked to NRF2-dependency in cancer cell lines, and observed that a significant portion of these genes is devoid of promoter-proximal NRF2 occupancy. Using integrated genomic analyses, we characterized extensive NRF2-dependent enhancer RNA (eRNA) synthesis and NRF2-mediated H3K27ac deposition at proximal and distal enhancer regions regulating these genes. While CBP/p300 is a well-validated direct interaction partner of NRF2 with prominent functions at enhancers, we report that this interaction is not required for NRF2-dependent NSCLC cell growth, indicating that NRF2 can sustain sufficient transcriptional activity in the absence of CBP/p300 coactivation. Broad metabolic profiling established a primary role for CBP/p300 in NRF2-dependent accumulation of glutathione and glutathione-related metabolites. While redox homeostasis via enhanced glutathione production is commonly associated with the normal physiological role of NRF2, collectively our results suggest that NRF2-dependent cancer cell growth does not require this enhanced glutathione production.

Auranofin resensitizes ferroptosis-resistant lung cancer cells to ferroptosis inducers

Lung cancer, a major cause of cancer-related mortality, has limited therapeutic options, especially for advanced cases. Ferroptosis, an iron-dependent form of cell death, is a potential therapeutic strategy for this disease; however, resistance mechanisms in the tumor microenvironment impede its effectiveness. Therefore, in this study, we aimed to investigate the efficacy of sulfasalazine (SAS), a ferroptosis inducer, and auranofin (AUR), a Food and Drug Administration-approved anti-inflammatory agent, combination to counteract ferroptosis resistance in lung cancer. SAS induced ferroptosis in vitro; however, its efficacy in vivo was limited, possibly because of factors, such as nutrient deprivation and high cell density, in the microenvironment that suppressed the activities of Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ), key regulators of ferroptosis resistance. Screening of 2483 drugs revealed AUR as a compound resensitizing the YAP/TAZ-deficient lung cancer cells to ferroptosis. Moreover, SAS and AUR combination significantly enhanced lipid peroxidation and reactive oxygen species accumulation, further driving ferroptosis in cells. This combination effectively inhibited tumor growth and enhanced survival in a murine lung cancer model. Overall, our findings suggest that AUR potentiates ferroptosis-based therapies, serving as an effective candidate to overcome ferroptosis resistance in lung cancer.

SiO2 particles induce pulmonary fibrosis by modulating NLRP3 through the ROS/Keap1/Nrf2 signaling pathway in rats

Recent studies have shown that the activation of the ROS-dependent NLRP3 inflammasome plays a key role in the pathogenesis of silicosis; however, the mechanism by which SiO2-induced ROS activates NLRP3 remains unclear. In this study, rats were intratracheally instilled with a SiO2 suspension once and then received daily intravenous injections of NAC (at doses of 20, 40, and 80 mg/kg, respectively) to inhibit SiO2-induced ROS. Rats that were intratracheally instilled with a SiO2 suspension once served as silicosis models, while those that were intratracheally instilled with PBS once served as controls. After 40 days, lung samples were taken for pathological observation, and the BALF was collected to measure ROS levels. The mRNA and protein expression levels of Keap1/Nrf2 signaling indicators (Keap1, Nrf2) and NLRP3 inflammasome indicators (NLRP3, GSDMD) were detected. The results showed that the Keap1/Nrf2 signaling pathway and the NLRP3 were activated in the silicosis rat lungs, accompanied by an increase in ROS levels. When ROS was inhibited, the Keap1/Nrf2 signaling pathway, the NLRP3, and the degree of pulmonary fibrosis were all suppressed in a dose-dependent manner. Therefore, we conclude that SiO2 particles induce pulmonary fibrosis in rats by modulating the NLRP3 inflammasome via the ROS/Keap1/Nrf2 signaling pathway.

Oncogenic KRAS addiction states differentially influence MTH1 expression and 8-oxodGTPase activity in lung adenocarcinoma

The efficacy of strategies targeting oncogenic RAS, prevalent in lung adenocarcinoma (LUAD), is limited by rapid adaptive resistance mechanisms. These include loss of RAS addiction and hyperactivation of downstream signaling pathways, such as PI3K/AKT. We previously reported that oncogenic RAS-driven LUAD cells possess an enhanced reliance on MTH1, the mammalian 8-oxodGTPase, to prevent genomic incorporation of oxidized nucleotides, and that MTH1 depletion compromises tumorigenesis and oncogenic signaling. Here, we show that elevated MTH1 correlates with poor prognosis in LUAD and that its redox-protective 8-oxodGTPase activity is variably regulated in KRAS-addicted vs. non-addicted states. Multiple oncogenic KRAS mutants or overexpression of wildtype (wt) KRAS increased MTH1 expression. Conversely, KRAS depletion or its inhibition by AMG-510 (sotorasib) decreased MTH1 in KRASG12C-addicted LUAD cells. Separation-of-function MEK/ERK1/2-activating mutants recapitulated the elevated MTH1 expression induced by oncogenic RAS in wt KRAS LUAD cells. However, upon inhibition of the MEK/ERK1/2 pathway, compensatory AKT activation maintained MTH1 expression. Indeed, elevated AKT signaling maintained high MTH1 expression even when KRAS oncoprotein was low. We previously reported that cancer cells possess variable MTH1-specific and MTH1-independent 8-oxodGTPase activity levels. Whereas both ERK1/2 and AKT could regulate MTH1 protein levels in KRAS-addicted cells, only AKT signaling was associated with elevated MTH1-specific 8-oxodGTPase activity under KRAS-low or KRAS non-addicted states. Our studies suggest that despite loss of KRAS dependency, LUAD cells retain the requirement for high MTH1 8-oxodGTPase activity due to redox vulnerabilities associated with AKT signaling. Thus, MTH1 may serve as a novel orthogonal vulnerability in LUAD that has lost KRAS addiction.

ISG15 Enhances the Activity of γ-Glutamate Cysteine Ligase to Suppress Apoptosis in High Fat Diet-Promoted Hepatocellular Carcinoma

Obesity is a leading risk factor for development of hepatocellular carcinoma (HCC). High-fat intake produces cytotoxic effects in liver cells, such as excessive reactive oxygen species (ROS) accumulation and apoptosis. How HCC cells regulate ROS level and escape the cytotoxic effects of high fat diet (HFD) stress remains unclear. Herein, this work reports a critical anti-ROS/apoptotic role of the ubiquitin-like protein interferon stimulated gene 15 (ISG15) in HFD-promoted HCC. In mouse models and clinical HCC samples, upregulation of ISG15 is associated with hepatic steatosis. Notably, upregulated ISG15 elevates cellular glutathione levels, which subsequently reduces ROS accumulation and confers resistance to apoptosis in HCC cells. In diethylnitrosamine-induced HCC mouse model, HFD-feeding promotes HCC progression in wildtype mice, while tumor growth is significantly suppressed accompanied by apoptosis of HCC cells in Isg15-KO mice. Mechanistically, ISG15 promotes the activity of γ-glutamate cysteine ligase (γ-GCL), a rate-limiting heterodimeric holoenzyme of glutathione synthesis consisting of glutamate-cysteine ligase catalytic subunit (GCLC) and glutamate-cysteine ligase modifier subunit (GCLM). Independent of ISGylation, ISG15 forms an ISG15/GCLM/GCLC complex that promotes GCLM-GCLC interaction, increases glutathione generation and inhibits HFD-induced apoptosis in HCC cells. Together, an anti-apoptotic ISG15-γ-GCL-glutothione axis is suggested in HFD-promoted HCC.

FAO-fueled OXPHOS and NRF2-mediated stress resilience in MICs drive lymph node metastasis

Metastasis is an inefficient process requiring cancer cells to adapt metabolically for survival and colonization in new environments. The contributions of tumor metabolic reprogramming to lymph node (LN) metastasis and its underlying mechanisms remain elusive. Through single-cell RNA sequencing, we identified rare metastasis-initiating cells (MICs) with stem-like properties that drive early LN metastasis. Integrated transcriptome, lipidomic, metabolomic, and functional analyses demonstrated that MICs depend on oxidative phosphorylation (OXPHOS) fueled by fatty acid oxidation (FAO) in the lipid-rich LN microenvironment. Mechanistically, the NRF2-SLC7A11 axis promotes glutathione synthesis to mitigate oxidative stress, thereby enhancing stress resistance and metastatic potential of MICs. Inhibition of NRF2-SLC7A11 reduced LN metastasis and sensitized tumors to cisplatin. Clinically, elevated NRF2-SLC7A11 expression was observed in tumors, with high expression correlating with LN metastasis, chemoresistance, and poor prognosis in esophageal squamous cell carcinoma (ESCC). These findings highlight the pivotal roles of FAO-fueled OXPHOS and NRF2 in LN metastasis and suggest targeting these pathways as a promising therapeutic strategy for metastatic ESCC.

Diet-induced phospholipid remodeling dictates ferroptosis sensitivity and tumorigenesis in the pancreas

High-fat diet (HFD) intake has been linked to an increased risk of pancreatic ductal adenocarcinoma (PDAC), a lethal and therapy-resistant cancer. However, whether and how specific dietary fats drive cancer development remains unresolved. Leveraging an oncogenic Kras -driven mouse model that closely mimics human PDAC progression, we screened a dozen isocaloric HFDs differing solely in fat source and representing the diversity of human fat consumption. Unexpectedly, diets rich in oleic acid - a monounsaturated fatty acid (MUFA) typically associated with good health - markedly enhanced tumorigenesis. Conversely, diets high in polyunsaturated fatty acids (PUFAs) suppressed tumor progression. Relative dietary fatty acid saturation levels (PUFA/MUFA) governed pancreatic membrane phospholipid composition, lipid peroxidation, and ferroptosis sensitivity in mice, concordant with circulating PUFA/MUFA levels being linked to altered PDAC risk in humans. These findings directly implicate dietary unsaturated fatty acids in controlling ferroptosis susceptibility and tumorigenesis, supporting potential "precision nutrition" strategies for PDAC prevention.

Targeting TUT1 Depletes Tri-snRNP Pools to Suppress Splicing and Inhibit Pancreatic Cancer Cell Survival

Pancreatic ductal adenocarcinoma (PDAC) is highly aggressive and lacks effective therapeutic options. Cancer cells frequently become more dependent on splicing factors than normal cells due to increased rates of transcription. Terminal uridylyltransferase 1 (TUT1) is a specific terminal uridylyltransferase for U6 small nuclear RNA (snRNA), which plays a catalytic role in the spliceosome. In this study, we found that TUT1 was required for the survival of PDAC cells but not for normal pancreatic cells. In PDAC cells, the uridylylation activity of TUT1 promoted U4/U6.U5 tri-small nuclear ribonucleoprotein particles (snRNP) assembly by facilitating the binding of LSM proteins to U6 snRNA and subsequent tri-snRNP assembly. PDAC cells required higher amounts of U4/U6.U5 tri-snRNP to efficiently splice pre-mRNA with weak splice sites to support the high transcriptional output. Depletion of TUT1 in PDAC cells resulted in inefficient splicing of exons in a group of highly expressed RNAs containing weak splice sites, thereby resulting in the collapse of an mRNA processing circuit and consequently dysregulating splicing required by PDAC cells. Overall, this study unveiled an interesting function of TUT1 in regulating splicing by modulating U4/U6.U5 tri-snRNP levels and demonstrated a distinct mechanism underlying splicing addiction in pancreatic cancer cells. Significance: The higher amounts of U6 snRNA in tri-snRNP pools in pancreatic cancer cells compared with normal cells confers sensitivity to TUT1 inhibition, which mimics tri-snRNP inhibition and causes pancreatic cancer cell senescence.

USP13: A therapeutic target for combating tumorigenesis and antitumor therapy resistance

Ubiquitin-specific peptidase 13 (USP13) has emerged as a key regulator of proteins critical to the hallmarks of cancer, playing an essential role in cellular regulation. This deubiquitinating enzyme, often overexpressed in malignancies, wields its molecular scissors precisely, snipping ubiquitin tags to rescue oncoproteins from degradation. Our review highlights the dual role of USP13 in cancer biology: while it predominantly fuels tumor growth and metastasis, USP13 occasionally functions as a tumor suppressor. USP13 is as a formidable factor in cancer therapy, fortifying tumors against an arsenal of treatments. It bolsters DNA repair mechanisms, ignites prosurvival autophagy, and even reprograms cell lineages to evade targeted therapies. However, USP13 is also a promising target in the treatment of cancer. We highlight burgeoning strategies to neutralize USP13, from small molecule inhibitors to innovative protein degraders, which may disarm cancer resistance mechanisms. We also offer suggestions for future USP13 research, emphasizing the need for structural insights and more potent inhibitors. This review highlights the critical role of USP13 in cancer and underscores its potential as a therapeutic target for advancing cancer treatment.

ML385, a selective inhibitor of Nrf2, demonstrates efficacy in the treatment of adult T-cell leukemia

Nrf2 plays a critical role in regulating cytoprotective transcriptional responses and glucose metabolism while also preventing inflammation-induced carcinogenesis. However, Nrf2 can paradoxically promote carcinogenesis. Here, we aimed to elucidate the role of Nrf2 in ATL associated with HTLV-1. HTLV-1-infected T-cell lines exhibited nuclear accumulation of Nrf2. Nrf2 knockdown along with the inhibition of its activity using ML385, decreased cell proliferation and survival. Furthermore, ML385-induced G1 arrest by enhancing γH2AX and p53 expression while downregulating CDK4/6, cyclin D2/E, and c-Myc. Additionally, ML385 triggered caspase-mediated apoptosis by downregulating the expression of anti-apoptotic proteins while upregulating pro-apoptotic proteins. The compound also induced necroptosis, promoted JNK phosphorylation, and inhibited the NF-κB, AP-1, and STAT3/5 signaling. Moreover, ML385 was found to reduce the expression of LDHA, glucose uptake, and the levels of lactate derived from glycolysis. Overall, these results suggest that Nrf2 functions as an oncogene in ATL and may represent a promising therapeutic target.

Lactate dehydrogenase B noncanonically promotes ferroptosis defense in KRAS-driven lung cancer

Ferroptosis is an oxidative, non-apoptotic cell death frequently inactivated in cancer, but the underlying mechanisms in oncogene-specific tumors remain poorly understood. Here, we discover that lactate dehydrogenase (LDH) B, but not the closely related LDHA, subunits of active LDH with a known function in glycolysis, noncanonically promotes ferroptosis defense in KRAS-driven lung cancer. Using murine models and human-derived tumor cell lines, we show that LDHB silencing impairs glutathione (GSH) levels and sensitizes cancer cells to blockade of either GSH biosynthesis or utilization by unleashing KRAS-specific, ferroptosis-catalyzed metabolic synthetic lethality, culminating in increased glutamine metabolism, oxidative phosphorylation (OXPHOS) and mitochondrial reactive oxygen species (mitoROS). We further show that LDHB suppression upregulates STAT1, a negative regulator of SLC7A11, thereby reducing SLC7A11-dependent GSH metabolism. Our study uncovers a previously undefined mechanism of ferroptosis resistance involving LDH isoenzymes and provides a novel rationale for exploiting oncogene-specific ferroptosis susceptibility to treat KRAS-driven lung cancer.

Redox signaling in the pancreas in health and disease

This review addresses oxidative stress and redox signaling in the pancreas under healthy physiological conditions as well as in acute pancreatitis, chronic pancreatitis, pancreatic cancer, and diabetes. Physiological redox homeodynamics is maintained mainly by NRF2/KEAP1, NF-κB, protein tyrosine phosphatases, peroxisome proliferator-activated receptor-γ coactivator 1α (PGC1α), and normal autophagy. Depletion of reduced glutathione (GSH) in the pancreas is a hallmark of acute pancreatitis and is initially accompanied by disulfide stress, which is characterized by protein cysteinylation without increased glutathione oxidation. A cross talk between oxidative stress, MAPKs, and NF-κB amplifies the inflammatory cascade, with PP2A and PGC1α as key redox regulatory nodes. In acute pancreatitis, nitration of cystathionine-β synthase causes blockade of the transsulfuration pathway leading to increased homocysteine levels, whereas p53 triggers necroptosis in the pancreas through downregulation of sulfiredoxin, PGC1α, and peroxiredoxin 3. Chronic pancreatitis exhibits oxidative distress mediated by NADPH oxidase 1 and/or CYP2E1, which promotes cell death, fibrosis, and inflammation. Oxidative stress cooperates with mutant KRAS to initiate and promote pancreatic adenocarcinoma. Mutant KRAS increases mitochondrial reactive oxygen species (ROS), which trigger acinar-to-ductal metaplasia and progression to pancreatic intraepithelial neoplasia (PanIN). ROS are maintained at a sufficient level to promote cell proliferation, while avoiding cell death or senescence through formation of NADPH and GSH and activation of NRF2, HIF-1/2α, and CREB. Redox signaling also plays a fundamental role in differentiation, proliferation, and insulin secretion of β-cells. However, ROS overproduction promotes β-cell dysfunction and apoptosis in type 1 and type 2 diabetes.

New insights into reductive stress responses and its clinical relation in cancer

Cells are susceptible to both oxidative and reductive stresses, with reductive stress being less studied and potentially therapeutic in cancer. Reductive stress, characterized by an excess of reducing equivalents exceeding the activity of endogenous oxidoreductases, can lead to an imbalance in homeostasis, causing an increase in reactive oxygen species induction, affecting cellular antioxidant load and flux. Unlike oxidative stress, reductive stress has been understudied and poorly understood, and there is still much to learn about its mechanisms in cancer, its therapeutic potential, and how cancer cells react to it. Changes in redox balance and interference with redox signaling are linked to cancer cell growth, metastasis, and resistance to chemotherapy and radiation. Overconsumption of reducing equivalents can reduce metabolism, alter protein disulfide bond formation, disrupt mitochondrial homeostasis, and disrupt cancer cell signaling pathways. Novel approaches to delivering or using cancer medicines and techniques to influence redox biology have been discovered. Under reductive stress, cancer cells may coordinate separate pools of redox pairs, potentially impacting biology.

Cooperative nutrient scavenging is an evolutionary advantage in cancer

The survival of malignant cells within tumours is often seen as depending on ruthless competition for nutrients and other resources1,2. Although competition is certainly critical for tumour evolution and cancer progression, cooperative interactions within tumours are also important, albeit poorly understood3,4. Cooperative populations at all levels of biological organization risk extinction if their population size falls below a critical tipping point5,6. Here we examined whether cooperation among tumour cells may be a potential therapeutic target. We identified a cooperative mechanism that enables tumour cells to proliferate under the amino acid-deprived conditions found in the tumour microenvironment. Disruption of this mechanism drove cultured tumour populations to the critical extinction point and resulted in a marked reduction in tumour growth in vivo. Mechanistically, we show that tumour cells collectively digest extracellular oligopeptides through the secretion of aminopeptidases. The resulting free amino acids benefit both aminopeptidase-secreting cells and neighbouring cells. We identified CNDP2 as the key enzyme that hydrolyses these peptides extracellularly, and loss of this aminopeptidase prevents tumour growth in vitro and in vivo. These data show that cooperative scavenging of nutrients is key to survival in the tumour microenvironment and reveal a targetable cancer vulnerability.

Selective targeting of genes regulated by zinc finger proteins in endometriosis and endometrioid adenocarcinoma by zinc niflumato complex with neocuproine

Inadequate angiogenesis of endometriotic implants stimulated by the inflammatory microenvironment in the uterine region leads to the development of gynecological diseases, which significantly reduce the fertility and vitality of young women. Angiogenic processes are controlled by factors whose activities are regulated at the gene level by reactive oxygen species (ROS), hypoxia-induced factors (HIFs), and zinc-finger proteins (ZnFs) or posttranscriptionally via non-coding RNAs. The cooperation of these factors is responsible for the manifestation of pathological stimuli in the form of endometriosis of the body of the uterus, ovaries, or peritoneum, from which endometrioid carcinoma can develop. Molecules that can control gene expression by their intercalation to target DNA sequence, such as [Zn(neo)(nif)2], could prevent the hyperactivation of pro-angiogenic pathways (decrease HIF-1α, VEGF-A, TGF-β1, COX2, and ANG2/ANG1), reduce the formation of ROS, and reduce the risk of uterine neoplasticity. The NSAID-metal complex [Zn(neo)(nif)2] shows an ability to intercalate into ZNF3-7 target DNA sequence at a higher rate, which could explain its effect on genes regulated by this transcription factor. In addition, [Zn(neo)(nif)2] affects ROS production and Ca2+ level, possibly pointing to mitochondrial dysfunction as a potential cause for the described apoptosis.

Targeting ubiquitin-independent proteasome with small molecule increases susceptibility in pan-KRAS-mutant cancer models

Despite advances in the development of direct KRAS inhibitors, KRAS-mutant cancers continue to exhibit resistance to the currently available therapies. Here, we identified REGγ as a mutant KRAS-associated factor that enhanced REGγ transcription through the KRAS intermediate NRF2, suggesting that the REGγ-proteasome is a potential target for pan-KRAS inhibitor development. We elucidated a mechanism involving the KRAS/NRF2/REGγ regulatory axis, which links activated KRAS to the ATP- and ubiquitin-independent proteasome. We subsequently developed RLY01, a REGγ-proteasome inhibitor that effectively suppressed tumor growth in KRAS-mutant cancer models and lung cancer organoids. Notably, the combination of RLY01 and the KRASG12C inhibitor AMG510 exhibited enhanced antitumor efficacy in KRASG12C cancer cells. Collectively, our data support the hypothesis that KRAS mutations enhance the capacity of the REGγ-proteasome by increasing REGγ expression, highlighting the potential of ubiquitin-independent proteasome inhibition as a therapeutic approach for pan-KRAS-mutant cancers.

CBX3 promotes multidrug resistance by suppressing ferroptosis in colorectal carcinoma via the CUL3/NRF2/GPX2 axis

Chemoresistance poses a significant challenge in colorectal cancer (CRC) treatment. However, the mechanisms underlying chemoresistance remain unclear. CBX3 promoted proliferation and metastasis in CRC. However, the role and mechanism of CBX3 in chemoresistance remain unknown. Therefore, we aimed to investigate the effects and mechanisms of CBX3 on multidrug resistance in CRC. Our studies showed that higher levels of CBX3 expression were associated with poor survival, especially in groups with progression following chemotherapy. CBX3 overexpression increased Irinotecan and Oxaliplatin resistance, whereas CBX3 knockdown suppressed multidrug resistance in CRC cells. Additionally, CBX3 inhibited ferroptosis associated with multidrug resistance, and the ferroptosis activators prevented CBX3 overexpression-mediated cell survival. RNA sequencing revealed that the NRF2-signaling pathway was involved in this process. CBX3-upregulated NRF2 protein expression by directly binding to the promoter of Cullin3 (CUL3) to suppress CUL3 transcription and CUL3-mediated NRF2 degradation. Moreover, Glutathione Peroxidase 2 (GPX2) was downstream of the CBX3-NRF2 pathway in CRC chemoresistance. ML385, an NRF2 inhibitor, suppressed GPX2 expression, and increased ferroptosis in PDX models. Our study identified CBX3/NRF2/GPX2 axis may be a novel signaling pathway that mediates multidrug resistance in CRC. This study proposes developing novel strategies for cancer treatment to overcome drug resistance in the future.

Predicting implicit concept embeddings for singular relationship discovery replication of closed literature-based discovery

Objective

Literature-based Discovery (LBD) identifies new knowledge by leveraging existing literature. It exploits interconnecting implicit relationships to build bridges between isolated sets of non-interacting literatures. It has been used to facilitate drug repurposing, new drug discovery, and study adverse event reactions. Within the last decade, LBD systems have transitioned from using statistical methods to exploring deep learning (DL) to analyze semantic spaces between non-interacting literatures. Recent works explore knowledge graphs (KG) to represent explicit relationships. These works envision LBD as a knowledge graph completion (KGC) task and use DL to generate implicit relationships. However, these systems require the researcher to have domain-expert knowledge when submitting relevant queries for novel hypothesis discovery.

Methods

Our method explores a novel approach to identify all implicit hypotheses given the researcher's search query and expedites the knowledge discovery process. We revise the KGC task as the task of predicting interconnecting vertex embeddings within the graph. We train our model using a similarity learning objective and compare our model's predictions against all known vertices within the graph to determine the likelihood of an implicit relationship (i.e., connecting edge). We also explore three approaches to represent edge connections between vertices within the KG: average, concatenation, and Hadamard. Lastly, we explore an approach to induce inductive biases and expedite model convergence (i.e., input representation scaling).

Results

We evaluate our method by replicating five known discoveries within the Hallmark of Cancer (HOC) datasets and compare our method to two existing works. Our results show no significant difference in reported ranks and model convergence rate when comparing scaling our input representations and not using this method. Comparing our method to previous works, we found our method achieves optimal performance on two of five datasets and achieves comparable performance on the remaining datasets. We further analyze our results using statistical significance testing to demonstrate the efficacy of our method.

Conclusion

We found our similarity-based learning objective predicts linking vertex embeddings for single relationship closed discovery replication. Our method also provides a ranked list of linking vertices between a set of inputs. This approach reduces researcher burden and allows further exploration of generated hypotheses.

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.

Gut Microbiota-Mediated hsa_circ_0126925 Targets BCAA Metabolic Enzyme BCAT2 to Exacerbate Colorectal Cancer Progression

Recent evidence indicates that a high-fat diet can promote tumor development, especially colorectal cancer, by influencing the microbiota. Regulatory circular RNA (circRNA) plays an important role in modulating host-microbe interactions; however, the specific mechanisms by which circRNAs influence cancer progression by regulating these interactions remain unclear. Here, we report that consumption of a high-fat diet modulates the microbiota by specifically upregulating the expression of the noncoding RNA hsa_circ_0126925 (herein, referred to as circ_0126925) in colorectal cancer. Acting as a scaffold, circ_0126925 hinders the recruitment of the E3 ubiquitin ligase tripartite motif-containing protein 21 (TRIM21) to branched-chain amino acid transaminase 2 (BCAT2), leading to reduced degradation of BCAT2. This reduction in targeted degradation of BCAT2 can protect tumors from limited branched-chain amino acid (BCAA) interference by improving the metabolism of BCAAs in colorectal cancer. Taken together, these data demonstrate that circ_0126925 plays a critical role in promoting the progression of colorectal cancer by maintaining BCAA metabolism and provide insight into the functions and crosstalk of circ_0126925 in host-microbe interactions in colorectal cancer. Implications: This study preliminarily confirms that circRNAs do indeed respond to microbiota/microbial metabolites, providing further evidence for the potential development of circRNAs as diagnostic tools and/or therapeutic agents to alleviate microbiome-related pathology in humans.

Intratumour oxidative hotspots provide a niche for cancer cell dissemination

Intratumour heterogeneity represents the hierarchical integration of genetic, phenotypic and microenvironmental heterogeneity. Although single-cell sequencing has clarified genetic and phenotypic variability, the heterogeneity of nongenetic, microenvironmental factors remains elusive. Here, we developed T-AP1, a tumour-targeted probe tracking extracellular H2O2, which allows the visualization and characterization of tumour cells exposed to oxidative stress, a hallmark of cancer. T-AP1 identified actively budding intratumour regions as H2O2-rich microenvironments (H2O2 hotspots), which were primarily established by neutrophils. Mechanistically, tumour cells exposed to H2O2 underwent partial epithelial-mesenchymal transition through p38-MYC axis activation and migrated away from H2O2 hotspots. This escape mechanism was absent in normal epithelial cells but prevalent in most cancers except NRF2-hyperactivated tumours, which exhibited abrogated p38 responses and enhanced antioxidant programmes, thus revealing an intrinsic stress defence programme in cancers. Together, T-AP1 enabled the identification of H2O2 hotspots that provide a niche for cancer cell dissemination, offering insights into metastasis initiation.

Examining the prognostic and clinicopathological significance of GPX4 in human cancers: a meta-analysis

Elevated levels of the enzyme GPX4 have been detected in tumor tissues, which may play a role in cancer progression. We did a meta-analysis of eight studies encompassing 1180 individuals to evaluate the importance of GPX4 in cancer, particularly in terms of prognosis and clinicopathological characteristics. Research results indicate that higher levels of GPX4 were linked to worse overall survival (OS) (HR = 1.47 [95%CI = 1.18-1.76], p < .001). Elevated levels of GPX4 were linked to lymph node invasion (OR.69 [95% CI.44-1.10], p =.12), metastasis (OR 1.58 [95% CI.97-2.55], p =.06, p <.0001), and advanced clinical stage III-IV (OR.82 [95% CI.70-.96], p =.001). A sensitivity study revealed that the general findings were constant across all levels of impact intensity. The findings of this meta-analysis suggest that increased GPX4 levels are not only correlated with reduced overall survival rates for patients with tumors but it also offers valuable insights regarding the clinical traits of tumor malignancy and metastasis. Based on these connections, GPX4 has the potential to serve as a biomarker for tumor detection, prognosis, and targeted therapy.

Regulating Nrf2 activity: ubiquitin ligases and signaling molecules in redox homeostasis

Transcription factor NF-E2 p45-related factor 2 (Nrf2) orchestrates defenses against oxidants and thiol-reactive electrophiles. It is controlled at the protein stability level by several E3 ubiquitin ligases (CRL3Keap1, CRL4DCAF11, SCFβ-TrCP, and Hrd1). CRL3Keap1 is of the greatest importance because it constitutively targets Nrf2 for proteasomal degradation under homeostatic conditions but is prevented from doing so by oxidative stressors. Repression of Nrf2 by CRL3Keap1 is attenuated by SQSTM1/p62, and this is reinforced by phosphorylation of SQSTM1/p62. Repression by SCFβ-TrCP requires phosphorylation of Nrf2 by GSK3, the activity of which is inhibited by PKB/Akt and other kinases. We discuss how Nrf2 activity is controlled by the ubiquitin ligases under different circumstances. We also describe endogenous signaling molecules that inactivate CRL3Keap1 to alleviate stress and restore homeostasis.

Effect of curcumin on lipid mediators, glycemic index, and oxidative stress and inflammation biomarkers in polycystic ovary syndrome: Future directions and current knowledge - A systematic review

Polycystic ovary syndrome (PCOS) is one of the most common and important polygenic endocrine disorders among women of reproductive-aged. Current treatments are mostly used only to control the signs and symptoms of the disease, while not being able to completely prevent complications. Curcumin is one of the active compounds in turmeric, which is commonly used for a wide range of metabolic and inflammatory diseases. Therefore, this systematic review was performed to evaluate the effect of curcumin supplementation on PCOS. The current systematic review was performed according to the guidelines of the 2015 PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) statements. We searched ProQuest, PubMed, Google Scholar electronic, Scopus, and Cochrane, Embase, and Science Direct databases and on articles published up until November 2024. All of the animal studies (seven studies) and clinical trials (five studies) included in this systematic review that assessed the effect of curcumin on, reproductive hormones and metabolic risk markers in PCOS were published in English-language journals. Most studies supported the beneficial effects of curcumin on folliculogenesis, ovarian histomorphology, and luteinization processes. The effects of curcumin on decreasing the levels of luteinizing insulin resistance luteinizing hormone (LH), Follicle-stimulating hormone (FSH)and testosterone, were also reported. Curcumin also improved dyslipidemia, but no significant effect on weight loss has been reported. It is suggested that the effect of curcumin in PCOS is more related to the antioxidant and anti-inflammatory properties of curcumin than to the effects of weight loss. Therefore, this study provides evidence that curcumin can be considered an effective factor in reducing the complications of PCOS. However, due to the low number of human studies in this field, further clinical trials are warranted to verify these outcomes.

USP13 facilitates a ferroptosis-to-autophagy switch by activation of the NFE2L2/NRF2-SQSTM1/p62-KEAP1 axis dependent on the KRAS signaling pathway

Macroautophagy/autophagyis a lysosomal-regulated degradation process that participates incellular stress and then promotes cell survival or triggers celldeath. Ferroptosis was initially described as anautophagy-independent, iron-regulated, nonapoptotic cell death.However, recent studies have revealed that autophagy is positivelyassociated with sensitivity to ferroptosis. Nonetheless, themolecular mechanisms by which these two types of regulated cell death(RCD) modulate each other remain largely unclear. Here, we screened85 deubiquitinating enzymes (DUBs) and found that overexpression ofUSP13 (ubiquitin specific peptidase 13) could significantlyupregulate NFE2L2/NRF2 (NFE2 like bZIP transcription factor 2)protein levels. In addition, in 39 cases of KRAS-mutated lungadenocarcinoma (LUAD), we found that approximately 76% of USP13overexpression is positively correlated with NFE2L2 overexpression.USP13 interacts with and catalyzes the deubiquitination of thetranscription factor NFE2L2. Additionally, USP13 depletion promotesan autophagy-to-ferroptosis switch invitro andin xenograft tumor mouse models, through the activation of theNFE2L2-SQSTM1/p62 (sequestosome 1)-KEAP1 axis in KRAS mutant cellsand tumor tissues. Hence, targeting USP13 effectively switchedautophagy-to-ferroptosis, thereby inhibiting KRAS (KRASproto-oncogene, GTPase) mutant LUAD, suggesting the therapeuticpromise of combining autophagy and ferroptosis in the KRAS-mutantLUAD.Abbreviation: ACSL4: acyl-CoA synthetase long-chain family member 4; ACTB: actin beta; AL: autolysosomes; AP: autophagosomes; BCL2L1/BCL-xL: BCL2 like 1; CCK8: Cell Counting Kit-8; CQ: chloroquine; CUL3: cullin 3; DMSO: dimethyl sulfoxide; DOX: doxorubicin; DUB: deubiquitinating enzyme; Ferr-1: ferrostatin-1; GPX4: glutathione peroxidase 4; GSEA: gene set enrichment analysis; 4HNE: 4-hydroxynonenal; IKE: imidazole ketone erastin; KEAP1: kelch like ECH associated protein 1; KRAS: KRAS proto-oncogene, GTPase; LCSC: lung squamous cell carcinoma; IF: immunofluorescence; LUAD: lung adenocarcinoma; Lys05: Lys01 trihydrochloride; MAPK1/ERK2/p42: mitogen-activated protein kinase 1; MAPK3/ERK1/p44; MTOR: mechanistic target of rapamycin kinase; NFE2L2/NRF2: NFE2 like bZIP transcription factor, 2; NQO1: NAD(P)H quinone dehydrogenase 1; PG: phagophore; RCD: regulated cell death; RAPA: rapamycin; ROS: reactive oxygen species; SLC7A11/xCT: solute carrier family 7 member 11; SQSTM1/p62: sequestosome 1; TEM: transmission electron microscopy; TUBB/beta-tubulin: tubulin, beta; UPS: ubiquitin-proteasome system; USP13: ubiquitin specific peptidase 13.

Lipid peroxidation and colorectal cancer risk: a time-varying relationship

Importance

We recently observed an inverse and time-dependent association between systemic oxidative stress (OxS), measured by urinary biomarkers of nucleic acid oxidation, and colorectal cancer (CRC) risk. Further investigations into other types of OxS markers are warranted.

Objective

To extend the investigation into systemic lipid peroxidation and CRC risk.

Design Setting and Participants

Utilizing a nested case-control design, this study's primary analysis was performed in two large prospective cohorts in Shanghai, China, and replicated in an independent cohort in the US.

Exposures

Systemic lipid peroxidation was assessed by urinary F 2 -isoprostanes (F 2 -IsoPs) using UPLC-MS/MS assays.

Main Outcomes and Measures

During 15.1-year follow-up in the Shanghai cohorts, 1938 incident CRC cases were identified and matched to one control each through incidence-density sampling. In the US cohort, 285 incident CRC cases were included, each matched to two controls. Odds ratios (ORs) for CRC were calculated using multivariable conditional logistic regression models.

Results

Elevated levels of urinary 5-F 2t -IsoP (5-iPF 2α -VI), a major isomer of F 2 -IsoPs induced solely by free radicals, were associated with reduced risk of CRC in the Shanghai cohorts. This finding was replicated in the US cohort. Moreover, this inverse association was time-dependent, manifesting only in the later years of cancer development. Multivariable-adjusted ORs (95% CI) for CRC diagnosed within 5 years of enrollment at the 10th and 90th percentiles of 5-F 2t -IsoP levels, relative to the median, were 1.57 (1.26-1.96) and 0.61 (0.42-0.89), respectively, indicating a 2.2-fold difference in risk between the two groups. A stronger association was observed when using the composite index of DNA, RNA and lipid OxS markers, showing a 3.9-fold difference in risk between the two groups. No significant association was found for CRC diagnosed beyond 5 years of enrollment.

Conclusions

This study provides new evidence that systemic OxS is inversely and time-dependently associated with CRC risk in humans.

Key Points

Question: Is the time-dependent relationship between oxidative stress and tumorigenesis observed at the cellular level in experimental models also present at the systemic level in a population-based setting?Findings: Elevated systemic lipid peroxidation, measured by urinary F 2 -isoprostanes, was associated with a reduced risk of colorectal cancer (CRC) in two large prospective cohort studies in Shanghai, China, which was replicated in an independent cohort in the United States. This association varied over time, showing a stronger effect as cancer advanced. Meaning: This study provides new evidence that systemic oxidative stress is inversely and time-dependently associated with CRC risk in humans.

Rhodoquinone carries electrons in the mammalian electron transport chain

Ubiquinone (UQ), the only known electron carrier in the mammalian electron transport chain (ETC), preferentially delivers electrons to the terminal electron acceptor oxygen (O2). In hypoxia, ubiquinol (UQH2) diverts these electrons onto fumarate instead. Here, we identify rhodoquinone (RQ), an electron carrier detected in mitochondria purified from certain mouse and human tissues that preferentially delivers electrons to fumarate through the reversal of succinate dehydrogenase, independent of environmental O2 levels. The RQ/fumarate ETC is strictly present in vivo and is undetectable in cultured mammalian cells. Using genetic and pharmacologic tools that reprogram the ETC from the UQ/O2 to the RQ/fumarate pathway, we establish that these distinct ETCs support unique programs of mitochondrial function and that RQ confers protection upon hypoxia exposure in vitro and in vivo. Thus, in discovering the presence of RQ in mammals, we unveil a tractable therapeutic strategy that exploits flexibility in the ETC to ameliorate hypoxia-related conditions.

Recent Anti-KRASG12D Therapies: A "Possible Impossibility" for Pancreatic Ductal Adenocarcinoma

Background: Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer, able to thrive in a challenging tumor microenvironment. Current standard therapies, including surgery, radiation, chemotherapy, and chemoradiation, have shown a dismal survival prognosis, resulting in less than a year of life in the metastatic setting. Methods: The pressing need to find better therapeutic methods brought about the discovery of new targeted therapies against the infamous KRAS mutations, the major oncological drivers of PDAC. Results: The most common KRAS mutation is KRASG12D, which causes a conformational change in the protein that constitutively activates downstream signaling pathways driving cancer hallmarks. Novel anti-KRASG12D therapies have been developed for solid-organ tumors, including small compounds, pan-RAS inhibitors, protease inhibitors, chimeric T cell receptors, and therapeutic vaccines. Conclusions: This comprehensive review summarizes current knowledge on the biology of KRAS-driven PDAC, the latest therapeutic options that have been experimentally validated, and developments in ongoing clinical trials.

From Pathophysiology to Treatment: The Role of Ferroptosis in PCOS

Polycystic ovary syndrome (PCOS) is a prevalent gynecological endocrine and metabolic disorder in women, with an incidence rate of 10-13%. The etiology of PCOS is multifaceted, involving genetic predisposition, environmental influences, lifestyle factors, and endocrine metabolic dysregulation. Iron, a critical mineral, not only plays a role in regulating female physiological functions and the progression of PCOS but also requires careful management to avoid deficiency. However, excess iron can trigger ferroptosis, a form of nonapoptotic cell death characterized by the accumulation of lipid peroxides. While numerous studies have explored ferroptosis in patients with PCOS and animal models, the precise mechanisms and therapeutic implications remain inadequately understood. This review seeks to elucidate the pathophysiology of PCOS and the contributory factors of ferroptosis. Additionally, we examine the diverse manifestations of ferroptosis in PCOS and evaluate its role. Furthermore, we introduce ferroptosis-related traditional Chinese medicines that may enhance the understanding of PCOS pathogenesis and aid in the development of targeted therapies for ferroptosis in PCOS.

Yersiniabactin produced by Escherichia coli promotes intestinal inflammation through lipid peroxidation and ferroptosis

Escherichia coli (E. coli), a major foodborne pathogen, poses significant risks to public health by causing gastrointestinal diseases. Among its virulence factors, Yersiniabactin (Ybt), a siderophore, plays a crucial role in iron acquisition and enhancing intestinal colonization. Despite previous studies highlighting E. coli-Ybt's involvement in inflammation, its exact mechanisms remain unclear. This study investigates how Ybt contributes to intestinal inflammation through ferroptosis, using both in vitro and in vivo models. Our findings demonstrate that Ybt promotes oxidative stress, lipid peroxidation, inflammation, and iron accumulation in intestinal epithelial cells, leading to ferroptosis. Mechanistically, Ybt suppresses the Keap1/Nrf2 pathway, amplifying reactive oxygen species (ROS) and activating the TNF/NF-κB pathway, which drives inflammation. Moreover, Ybt induces lipid peroxidation via the arachidonic acid pathway, producing 6-trans-leukotriene B4 (6-transLTB4), which exacerbates inflammation and ferroptosis. Exogenous 6-transLTB4 further intensifies this cascade. Additionally, Ybt disrupts iron efflux by suppressing FPN1 expression, causing excessive intracellular iron accumulation. Using tree shrews as an in vivo model, we confirm that Ybt-induced ferroptosis significantly aggravates intestinal inflammation. These findings underscore the pathogenic role of Ybt in E. coli-induced intestinal injury and highlight ferroptosis as a novel mechanism contributing to gut health disruption. This study provides new insights into the molecular pathways of E. coli infection, with implications for therapeutic strategies targeting ferroptosis in intestinal diseases.

Copper Drives Remodeling of Metabolic State and Progression of Clear Cell Renal Cell Carcinoma

SIGNIFICANCE

The work establishes a requirement for glucose-dependent coordination between energy production and redox homeostasis, which is fundamental for the survival of cancer cells that accumulate Cu and contributes to tumor growth.

Extracellular vesicles deliver thioredoxin to rescue stem cells from senescence and intervertebral disc degeneration via a feed-forward circuit of the NRF2/AP-1 composite pathway

Intervertebral disc degeneration (IDD) is largely attributed to impaired endogenous repair. Nucleus pulposus-derived stem cells (NPSCs) senescence leads to endogenous repair failure. Small extracellular vesicles/exosomes derived from mesenchymal stem cells (mExo) have shown great therapeutic potential in IDD, while whether mExo could alleviate NPSCs senescence and its mechanisms remained unknown. We established a compression-induced NPSCs senescence model and rat IDD models to evaluate the therapeutic efficiency of mExo and investigate the mechanisms. We found that mExo significantly alleviated NPSCs senescence and promoted disc regeneration while knocking down thioredoxin (TXN) impaired the protective effects of mExo. TXN was bound to various endosomal sorting complex required for transport (ESCRT) proteins. Autocrine motility factor receptor (AMFR) mediated TXN K63 ubiquitination to promote the binding of TXN on ESCRT proteins and sorting of TXN into mExo. Knocking down exosomal TXN inhibited the transcriptional activity of nuclear factor erythroid 2-related factor 2 (NRF2) and activator protein 1 (AP-1). NRF2 and AP-1 inhibition reduced endogenous TXN production that was promoted by exosomal TXN. Inhibition of NRF2 in vivo diminished the anti-senescence and regenerative effects of mExo. Conclusively, AMFR-mediated TXN ubiquitination promoted the sorting of TXN into mExo, allowing exosomal TXN to promote endogenous TXN production in NPSCs via TXN/NRF2/AP-1 feed-forward circuit to alleviate NPSCs senescence and disc degeneration.

Model organisms for investigating the functional involvement of NRF2 in non-communicable diseases

Non-communicable chronic diseases (NCDs) are most commonly characterized by age-related loss of homeostasis and/or by cumulative exposures to environmental factors, which lead to low-grade sustained generation of reactive oxygen species (ROS), chronic inflammation and metabolic imbalance. Nuclear factor erythroid 2-like 2 (NRF2) is a basic leucine-zipper transcription factor that regulates the cellular redox homeostasis. NRF2 controls the expression of more than 250 human genes that share in their regulatory regions a cis-acting enhancer termed the antioxidant response element (ARE). The products of these genes participate in numerous functions including biotransformation and redox homeostasis, lipid and iron metabolism, inflammation, proteostasis, as well as mitochondrial dynamics and energetics. Thus, it is possible that a single pharmacological NRF2 modulator might mitigate the effect of the main hallmarks of NCDs, including oxidative, proteostatic, inflammatory and/or metabolic stress. Research on model organisms has provided tremendous knowledge of the molecular mechanisms by which NRF2 affects NCDs pathogenesis. This review is a comprehensive summary of the most commonly used model organisms of NCDs in which NRF2 has been genetically or pharmacologically modulated, paving the way for drug development to combat NCDs. We discuss the validity and use of these models and identify future challenges.

The multifaceted anticancer potential of luteolin: involvement of NF-κB, AMPK/mTOR, PI3K/Akt, MAPK, and Wnt/β-catenin pathways

Cancer is the predominant and major cause of fatality worldwide, based on the different types of cancer. There is a limitation in the current treatment. So we need better therapeutic agents that counteract the progression and development of malignant tumours. Plant-derived products are closely related and useful for human health. Luteolin is a polyphenolic flavonoid bioactive molecule that is present in various herbs, vegetables, fruits, and flowers and exhibits chemoprotective and pharmacological activity against different malignancies. To offer innovative approaches for the management of various cancers, we present a comprehensive analysis of the latest discoveries on luteolin. The aim is to inspire novel concepts for the development of advanced pharmaceuticals targeting cancer and search specifically targeted reviews and research articles published from January 1999 to January 2024 that investigated the application of luteolin in various cancer management. A thorough literature search utilizing the keywords "luteolin" "Signalling Pathway" "cancer" and nanoparticles was performed in the databases of Google Scholar, Web of Science, SCOPUS, UGC care list and PubMed. Through the compilation of existing research, we have discovered that luteolin possesses several therapeutic actions against various cancer via a signaling pathway involving the of NF-κB regulation, AMPK/mTOR, toll-like receptor, Nrf-2, PI3K/Akt MAPK and Wnt/β-catenin and their underlying mechanism of action has been well understood. This review intended to completely integrate crucial information on natural sources, biosynthesis, pharmacokinetics, signaling pathways, chemoprotective and therapeutic properties against various cancers, and nanoformulation of luteolin.

Time-dependent relationship between urinary biomarkers of nucleic acid oxidation and colorectal cancer risk

PURPOSE

Randomized controlled trials have failed to validate that neutralizing oxidative stress (OxS) through antioxidant supplementation reduces cancer risk. This study aims to prospectively investigate whether the relationship between systemic OxS and colorectal cancer (CRC) risk changes over the course of cancer development.

METHODS

This study utilized a nested case-control design in two Shanghai cohorts for primary analysis and one US cohort for replication analysis. During a median follow-up of 15.1 years in the Shanghai cohorts, 1938 incident CRC cases were identified and matched to one control each. In the US cohort, 285 incident CRC cases were included with two matched controls per case. Systemic OxS was assessed by urinary markers of DNA oxidation (8-oxo-7,8-dihydro-2'-deoxyguanosine [8-oxo-dG]) and RNA oxidation (7,8-dihydro-8-oxo-guanosine [8-oxo-Guo]) using UPLC-MS/MS assays. Multivariable-adjusted odds ratios (ORs) for CRC risk were calculated.

RESULTS

After adjusting for potential confounders, we observed an inversion association between OxS markers and CRC risk in the Shanghai cohorts, which was independently replicated in the US cohort. Moreover, the inverse association was time-dependent, manifesting only for CRC cases diagnosed within 5 years of enrollment. ORs (95% CI) for CRC at the 10th and 90th percentiles of 8-oxo-dG levels, relative to the median, were 1.87 (1.39 to 2.53) and 0.48 (0.37 to 0.63), respectively, demonstrating an approximate 4-fold difference in risk between the two groups, with P for overall association of < 0.001. A similar pattern was observed for 8-oxo-Guo. No significant association was found for CRC diagnosed beyond 5 years of enrollment.

CONCLUSION

This novel finding of an inverse and time-dependent relationship between systemic OxS and CRC risk, if further confirmed, may provide a new perspective for revisiting redox-based chemoprevention.

CONTEXT

Background: Almost all large randomized controlled trials have failed to validate the hypothesis that neutralizing oxidative stress through antioxidant supplementation can lower cancer risk, which has puzzled the public and researchers for decades.Key Findings: A reduced risk for colorectal cancer (CRC) with increasing systemic oxidative stress, measured by two urinary biomarkers of DNA and RNA oxidation, was observed in two large prospective cohort studies in Shanghai, China, and was replicated in an independent cohort in the United States. This association was time-dependent, with the inverse relationship strengthening as the biomarker assessment neared the time of CRC diagnosis.Relevance: Our study, for the first time, suggests an inverse and time-dependent relationship between systemic oxidative stress and CRC development, which, if further confirmed, may provide a new perspective for revisiting redox-based chemoprevention.

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.

Alogliptin attenuates STZ-induced diabetic nephropathy in rats through the modulation of autophagy, apoptosis, and inflammation pathways: Targeting NF-κB and AMPK/mTOR pathway

AIM

Diabetic nephropathy (DN) is a type of microvascular complication that arises from diabetes mellitus and leads to further health issues. Most importantly, the prevalence of DN is steadily rising in developed countries. This research explored the therapeutic benefits of alogliptin, a dipeptidyl peptidase IV (DPP-4) inhibitor, on streptozotocin (STZ)-induced DN and its underlying mechanisms in rats.

MAIN METHODS

Ten rats were allocated to group 1, served as the normal group; and received saline. To develop diabetes, thirty rats were administered a single intraperitoneal dose of STZ (45 mg/kg). STZ-induced diabetic rats were randomly assigned to three groups: group 2 diabetic control; was given saline, groups 3 and 4 received alogliptin (10 mg/kg) and (20 mg/kg), respectively. The treatment began 8 weeks after diabetes onset and continued for four weeks. Histopathological alterations in the kidney were detected. Serum was collected to measure blood glucose levels (BGL), renal function, and lactate dehydrogenase (LDH). Tissue samples were collected to detect changes in oxidative stress (OS), inflammation, 5' adenosine monophosphate-activated protein kinase (AMPK), and the mammalian target of Rapamycin (mTOR) signaling pathways in addition to apoptotic and autophagy changes.

KEY FINDINGS

Alogliptin reduced STZ-induced histological changes in the kidney as well as OS, and inflammation. Alogliptin also ameliorated the AMPK/mTOR signaling pathways, enhanced autophagy, and reduced apoptosis.

SIGNIFICANCE

These results demonstrate that alogliptin ameliorates inflammation and OS and consequently modulates the AMPK/mTOR axis along with targeting autophagy and apoptosis, leading to the alleviation of DN.

PHGDH Induction by MAPK Is Essential for Melanoma Formation and Creates an Actionable Metabolic Vulnerability

Overexpression of phosphoglycerate dehydrogenase (PHGDH), the rate-limiting enzyme in the serine synthesis pathway, promotes melanomagenesis, melanoma cell proliferation, and survival of metastases in serine-low environments such as the brain. Here, we found that PHGDH is universally increased in melanoma cells and required for melanomagenesis. Although PHGDH amplification explained PHGDH overexpression in a subset of melanomas, oncogenic BRAFV600E also promoted PHGDH transcription through mTORC1-mediated translation of ATF4. Importantly, depletion of PHGDH in genetic mouse melanoma models blocked tumor formation. In addition to BRAFV600E-mediated upregulation, PHGDH was further induced by exogenous serine restriction. Surprisingly, BRAFV600E inhibition diminished serine restriction-mediated PHGDH expression by preventing ATF4 induction. Consequently, melanoma cells could be specifically starved of serine by combining BRAFV600E inhibition with exogenous serine restriction, which promoted cell death in vitro and attenuated melanoma growth in vivo. In summary, this study identified that PHGDH is essential for melanomagenesis and regulated by BRAFV600E, revealing a targetable vulnerability in BRAFV600E-mutant melanoma. Significance: BRAFV600E promotes the expression of the serine synthesis enzyme PHGDH, which is required for melanoma formation, and can be targeted to sensitize melanoma to dietary serine restriction, providing a melanoma cell-specific treatment strategy.

Ferroptosis and its relationship with cancer

Marked by iron buildup and lipid peroxidation, ferroptosis is a relatively new regulatory cell death (RCD) pathway. Many diseases like cancer, myocardial ischemia-reperfusion injury (MIRI), neurological disorders and acute renal failure (AKI) are corelated with ferroptosis. The main molecular processes of ferroptosis discovered yet will be presented here, along with the approaches in which it interacts with tumour-associated signaling pathways and its uses in systemic therapy, radiation therapy, and immunotherapy managing tumors.

Design of a Magnetic Nanoplatform Based on CD26 Targeting and HSP90 Inhibition for Apoptosis and Ferroptosis-Mediated Elimination of Senescent Cells

The accumulation of senescent cells, a hallmark of aging and age-related diseases, is also considered as a side effect of anticancer therapies, promoting drug resistance and leading to treatment failure. The use of senolytics, selective inducers of cell death in senescent cells, is a promising pharmacological antiaging and anticancer approach. However, more studies are needed to overcome the limitations of first-generation senolytics by the design of targeted senolytics and nanosenolytics and the validation of their usefulness in biological systems. In the present study, we have designed a nanoplatform composed of iron oxide nanoparticles functionalized with an antibody against a cell surface marker of senescent cells (CD26), and loaded with the senolytic drug HSP90 inhibitor 17-DMAG (MNP@CD26@17D). We have documented its action against oxidative stress-induced senescent human fibroblasts, WI-38 and BJ cells, and anticancer drug-induced senescent cutaneous squamous cell carcinoma A431 cells, demonstrating for the first time that CD26 is a valid marker of senescence in cancer cells. A dual response to MNP@CD26@17D stimulation in senescent cells was revealed, namely, apoptosis-based early response (2 h treatment) and ferroptosis-based late response (24 h treatment). MNP@CD26@17D-mediated ferroptosis might be executed by ferritinophagy as judged by elevated levels of the ferritinophagy marker NCOA4 and a decreased pool of ferritin. As 24 h treatment with MNP@CD26@17D did not induce hemolysis in human erythrocytes in vitro, this newly designed nanoplatform could be considered as an optimal multifunctional tool to target and eliminate senescent cells of skin origin, overcoming their apoptosis resistance.

Targeting KRAS: from metabolic regulation to cancer treatment

The Kirsten rat sarcoma viral oncogene homolog (KRAS) protein plays a key pathogenic role in oncogenesis, cancer progression, and metastasis. Numerous studies have explored the role of metabolic alterations in KRAS-driven cancers, providing a scientific rationale for targeting metabolism in cancer treatment. The development of KRAS-specific inhibitors has also garnered considerable attention, partly due to the challenge of acquired treatment resistance. Here, we review the metabolic reprogramming of glucose, glutamine, and lipids regulated by oncogenic KRAS, with an emphasis on recent insights into the relationship between changes in metabolic mechanisms driven by KRAS mutant and related advances in targeted therapy. We also focus on advances in KRAS inhibitor discovery and related treatment strategies in colorectal, pancreatic, and non-small cell lung cancer, including current clinical trials. Therefore, this review provides an overview of the current understanding of metabolic mechanisms associated with KRAS mutation and related therapeutic strategies, aiming to facilitate the understanding of current challenges in KRAS-driven cancer and to support the investigation of therapeutic strategies.

Metabolic Reprogramming at the Edge of Redox: Connections Between Metabolic Reprogramming and Cancer Redox State

The importance of redox systems as fundamental elements in biology is now widely recognized across diverse fields, from ecology to cellular biology. Their connection to metabolism is particularly significant, as it plays a critical role in energy regulation and distribution within organisms. Over recent decades, metabolism has emerged as a relevant focus in studies of biological regulation, especially following its recognition as a hallmark of cancer. This shift has broadened cancer research beyond strictly genetic perspectives. The interaction between metabolism and redox systems in carcinogenesis involves the regulation of essential metabolic pathways, such as glycolysis and the Krebs cycle, as well as the involvement of redox-active components like specific amino acids and cofactors. The feedback mechanisms linking redox systems and metabolism in cancer highlight the development of redox patterns that enhance the flexibility and adaptability of tumor processes, influencing larger-scale biological phenomena such as circadian rhythms and epigenetics.

Ferroptosis-related signaling pathways in cancer drug resistance

Ferroptosis is an iron-dependent form of programmed cell death induced by lipid peroxidation. This process is regulated by signaling pathways associated with redox balance, iron metabolism, and lipid metabolism. Cancer cells' increased iron demand makes them especially susceptible to ferroptosis, significantly influencing cancer development, therapeutic response, and metastasis. Recent findings indicate that cancer cells can evade ferroptosis by downregulating key signaling pathways related to this process, contributing to drug resistance. This underscores the possibility of modulating ferroptosis as an approach to counteract drug resistance and enhance therapeutic efficacy. This review outlines the signaling pathways involved in ferroptosis and their interactions with cancer-related signaling pathways. We also highlight the current understanding of ferroptosis in cancer drug resistance, offering insights into how targeting ferroptosis can provide novel therapeutic approaches for drug-resistant cancers. Finally, we explore the potential of ferroptosis-inducing compounds and examine the challenges and opportunities for drug development in this evolving field.

Regulation of SLC7A11 as an unconventional checkpoint in tumorigenesis through ferroptosis

Although cell-cycle arrest, senescence, and apoptosis are well accepted as the classic barriers in tumorigenesis, recent studies indicate that metabolic regulation is equally important as a major checkpoint in cancer development. It is well accepted that ferroptosis, an iron-dependent programmed cell death, acts as a new type of tumor suppression mechanism tightly linked with numerous metabolic pathways. SLC7A11 is a transmembrane cystine/glutamate transporter protein that plays a vital role in controlling ferroptosis in vivo. The levels of SLC7A11 are dynamically regulated by various types of stresses, such as oxidative stress, nutrient deprivation, endoplasmic reticulum stress, radiation, oncogenic stress, DNA damage, and immune stress. SLC7A11 can be transcriptionally regulated by both activators such as ATF4, NRF2, and ETS1, and repressors including BACH1, p53, ATF3, and STAT1 during stress responses. Moreover, SLC7A11 activity and its protein stability and cellular localization are also modulated upon stress. Patients' data show that SLC7A11 is overexpressed in various types of human cancers, and higher levels of SLC7A11 predict poorer overall survival. Growing evidence also suggests that targeting SLC7A11 is a promising approach in cancer therapy by effectively inhibiting tumor proliferation, invasion, and metastasis, as well as counteracting cancer stem cells and overcoming chemoresistance. This review highlights the regulation of SLC7A11 as an unconventional checkpoint in tumorigenesis through modulating ferroptotic responses under various types of stress.

STK11 mutations correlate with poor prognosis for advanced NSCLC treated with first-line immunotherapy or chemo-immunotherapy according to KRAS, TP53, KEAP1, and SMARCA4 status

BACKGROUND

The upfront treatment of non-oncogene-addicted NSCLC relies on immunotherapy alone (ICI) or in combination with chemotherapy (CT-ICI). Genomic aberrations such as KRAS, TP53, KEAP1, SMARCA4, or STK11 may impact survival outcomes.

METHODS

We performed an observational study of 145 patients treated with first-line IO or CT-ICI for advanced non-squamous (nsq) NSCLC at our institution tested with an extensive lab-developed NGS panel. The primary objective was to assess the clinical outcomes of STK11-mutated patients. Then, we performed an external validation through the public OAK/POPLAR dataset, including nsq NSCLC patients treated with single-agent ICI or CT.

RESULTS

Most patients were male (59.7 %), former smokers (61.1 %), with ECOG PS 0-1 (84 %), and received first-line CT-IO (58.6 %). 44.8 % had a mutation in KRAS, 21.4 % in KEAP1, 50.3 % in TP53, 13.1 % in SMARCA4, and 14.4 % in the STK11 gene. The mOS was 8 mo. (95 % CI, 5-16.7) for STK11 mutated pts and 17.3 mo. for STK11 wild-type patients (95 % CI, 8.9-24.4) (p = 0.038). TP53 (8.3 vs 17.3), KRAS (9.2 vs 15.9), and KEAP1 (8.9 vs 15.9) mutated patients evidenced a trend for dismal mOS. SMARCA4 status had no impact on mOS. STK11 mutations were detrimental to OS in the univariate (HR 1.74, p = 0.041) and multivariate model (HR 1.97, p = 0.025) after adjusting for sex, age, ECOG PS, treatment (ICI vs CT-ICI), KRAS, KEAP1, TP53, and SMARCA4 status. Genomic alterations did not impact the mPFS in our cohort. Within the OAK/POPLAR dataset, STK11 mutations (60/818 pts) were significantly associated with increased death risk in the univariate (HR 2.01, p < 0.001) and multivariate model (HR 1.66, p = 0.001) after adjusting for age, sex, treatment (ICI vs CT), KRAS, KEAP1, TP53, and SMARCA4 status.

CONCLUSION

STK11 aberrations hampered the mOS of nsq NSCLC patients treated with first-line ICI or CT-ICI. The negative prognostic impact seems to be unrelated to ICI administration.

Reactive Oxygen Species and its Manipulation Strategies in Cancer Treatment

Cancer is one of the serious diseases of modern times, occurring in all parts of the world and shows a wide range of effects on the human body. Reactive Oxygen Species (ROS) such as oxide and superoxide ions have both advantages and disadvantages during the progression of cancer, dependent on their concentration. It is a necessary part of the normal cellular mechanisms. Changes in its normal level can cause oncogenesis and other relatable problems. Metastasis can also be controlled by ROS levels in the tumor cells, which can be prevented by the use of antioxidants. However, ROS is also used for the initiation of apoptosis in cells by different mediators. There exists a cycle between the production of oxygen reactive species, their effect on the genes, role of mitochondria and the progression of tumors. ROS levels cause DNA damage by the oxidation process, gene damage, altered expression of the genes and signalling mechanisms. They finally lead to mitochondrial disability and mutations, resulting in cancer. This review summarizes the important role and activity of ROS in developing different types of cancers like cervical, gastric, bladder, liver, colorectal and ovarian cancers.

LRRC45 accelerates bladder cancer development and ferroptosis inhibition via stabilizing NRF2 by competitively KEAP1 interaction

Centrosomal dysregulation is closely linked to the genesis and progression of tumors. A comprehensive analysis of single-cell RNA sequencing (scRNA-seq) data has revealed that leucine-rich repeat-containing protein 45 (LRRC45), a centrosome linker protein crucial for maintaining centrosome cohesion and a member of the leucine-rich repeat-containing proteins (LRRCs) family, is significantly upregulated in bladder cancer. Notably, the elevated expression levels of LRRC45 were strongly correlated with a poor prognosis in patients. Furthermore, the depletion of LRRC45 in bladder cancer cells markedly inhibited tumorigenic proliferation and increased intracellular iron and reactive oxygen species (ROS) levels. It ultimately triggered ferroptosis, an iron-dependent form of programmed cell death characterized by lipid peroxidation. Mechanistic studies revealed that LRRC45 exerts its oncogenic effects through competitive interaction with Kelch-like ECH-associated protein 1 (KEAP1), which inhibits the ubiquitin-proteasome-mediated degradation of nuclear factor erythroid 2-related factor 2 (NRF2). This interaction enhances the nuclear translocation of NRF2 and its subsequent anti-ferroptotic activity. In conclusion, our studies highlight the critical role of LRRC45 in enhancing the stability of NRF2, thereby promoting the tumorigenic potential of bladder cancer. These insights suggest that targeting LRRC45 could serve as a promising molecular target for developing novel therapeutic interventions for bladder cancer.