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Despite adjuvant treatment with endocrine therapies, estrogen receptor-positive (ER+) breast cancers recur in a significant proportion of patients. Recurrences are attributable to clinically undetectable endocrine-tolerant persister cancer cells that retain tumor-forming potential. Therefore, strategies targeting such persister cells may prevent recurrent disease. Using CRISPR-Cas9 genome-wide knockout screening in ER+ breast cancer cells, we identified a survival mechanism involving metabolic reprogramming with reliance upon mitochondrial respiration in endocrine-tolerant persister cells. Quantitative proteomic profiling showed reduced levels of glycolytic proteins in persisters. Metabolic tracing of glucose revealed an energy-depleted state in persisters, in which oxidative phosphorylation was required to generate ATP. A phase II clinical trial was conducted to evaluate changes in mitochondrial markers in primary ER+/HER2- breast tumors induced by neoadjuvant endocrine therapy (NCT04568616). In an analysis of tumor specimens from 32 patients, tumors exhibiting residual cell proliferation after aromatase inhibitor-induced estrogen deprivation with letrozole showed increased mitochondrial content. Genetic profiling and barcode lineage tracing showed that endocrine-tolerant persistence occurred stochastically without genetic predisposition. Pharmacologic inhibition of mitochondrial complex I suppressed the tumor-forming potential of persisters in mice and synergized with the antiestrogen drug fulvestrant to induce regression of patient-derived xenografts. These findings indicate that mitochondrial metabolism is essential in endocrine-tolerant persister ER+ breast cancer cells and warrant the development of treatment strategies to leverage this vulnerability for treating breast cancer. Significance: Persister cancer cells that survive endocrine therapy exhibit increased energetic dependence upon mitochondria for survival and tumor regrowth potential, indicating that therapies targeting this metabolic dependency could help prevent disease recurrence. Show less

Mitochondria are associated with cellular energy metabolism, proliferation, and mode of death. Damage to mitochondrial DNA (mtDNA) greatly affects mitochondrial function by interfering with energy production and the signaling pathway. Monofunctional trinuclear platinum complex MTPC demonstrates different actions on the mtDNA of cancerous and normal cells. It severely impairs the integrity and function of mitochondria in the human lung cancer A549 cells, such as dissipating mitochondrial membrane potential, decreasing the copy number of mtDNA, interfering in nucleoid proteins and polymerase gamma gene, reducing adenosine triphosphate (ATP), and inducing mitophagy, whereas it barely affects the mtDNA of the human kidney 2 (HK-2) cells. Moreover, MTPC promotes the release of mtDNA into the cytosol and stimulates the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway, thus showing the potential to trigger antitumor immunity. MTPC displays significant cytotoxicity against A549 cells, while it exhibits weak toxicity toward HK-2 cells, therefore displaying great advantage to overcome the lingering nephrotoxicity of platinum anticancer drugs. Discrepant effects of a metal complex on mitochondria of different cells mean that targeting mitochondria has special significance in cancer therapy. Show less

The effectiveness of existing systemic and targeted therapies remains limited in triple-negative breast cancer (TNBC) treatment. Much research has been conducted on reactive oxygen species (ROS)-mediated cancer cell death to overcome the shortcomings of the currently applied chemotherapeutic treatments. Herein, we have developed novel Ru(II)/Ir(III)-mediated triazolylpyridine complexes as ROS inducers. Upon entering the TNBC cells, the Ru(II) complex effectively accumulated in mitochondria and triggered the creation of ROS, facilitating dysfunction of mitochondria and oxidative DNA damage, ultimately causing death of cells through G2/M phase cell cycle arrest. Eventually, this complex induced the upregulation of BAX (pro-apoptotic protein) and downregulation of BCL-2 (antiapoptotic protein) and triggered the caspase 3/9 pathway and released cytochrome c in the cytosol for apoptosis. The complex JRu (RuII triazolylpyridine) significantly reduced the integrity and viability of TNBC 3D spheroids. Show less

Nucleotide excision repair (NER) is a universal cut-and-paste DNA repair mechanism that corrects bulky DNA lesions such as those caused by UV radiation, environmental mutagens, and some chemotherapy drugs. In this review, we focus on the human transcription/DNA repair factor TFIIH, a key player of the NER pathway in eukaryotes. This 10-subunit multiprotein complex notably verifies the presence of a lesion and opens the DNA around the damage via its XPB and XPD subunits, two proteins identified in patients suffering from Xeroderma Pigmentosum syndrome. Isolated as a class II gene transcription factor in the late 1980s, TFIIH is a prototypic molecular machine that plays an essential role in both DNA repair and transcription initiation and harbors a DNA helicase, a DNA translocase, and kinase activity. More recently, TFIIH subunits have been identified as participating in other cellular processes, including chromosome segregation during mitosis, maintenance of mitochondrial DNA integrity, and telomere replication. Show less

Background Rhabdomyolysis (RM), particularly heat exhaustion-associated rhabdomyolysis (ehsRM), is a significant clinical issue associated with high mortality and healthcare costs. However, the cellular death mechanisms remain incompletely understood. Oncosis, a form of passive cell death distinct from apoptosis, is characterized by cell swelling and triggered by ATP depletion. Additionally, porimin, a specific biomarker, can uniquely identify oncosis. This study aims to investigate the role and mechanisms of oncosis in both in vitro and in vivo models of ehsRM. Objective This study aims to investigate the role and mechanisms of oncosis in both in vitro and in vivo models of ehsRM. Methods In the in vitro study, 6-8-week-old male rats were subjected to treadmill exercise at an ambient temperature of (39.5 ± 0.5)°C and relative humidity of 50%-60%, at a speed of 15 meters per minute until their core body temperature (Tc) reached 43.0°C to establish a heatstroke animal model. Skeletal muscle and blood samples from the gastrocnemius were collected for cytokine, biochemical, and histopathological analyses. Pathological findings revealed decreased muscle fiber density, structural disarray, swelling, degeneration, and hemorrhage. Ultrastructural analysis showed cell swelling, structural disarray, cytoplasmic vacuolation, mitochondrial swelling and degeneration, loss of cristae, and nuclear degeneration, indicating myocyte swelling and necrosis. Porimin, CytC, Bax, and caspase-1 expression increased, while Bcl-2 expression decreased. JC-1 staining indicated a decline in mitochondrial membrane potential and dysfunction. ATP levels decreased, and reactive oxygen species (ROS) production increased. In the in vivo study, HSKMC cells were subjected to 4 hours of heat shock at 43°C to establish a heatstroke-induced rhabdomyolysis cell model. Electron microscopy revealed cell swelling, cytoplasmic vacuolation, mitochondrial swelling and degeneration, and nuclear swelling; late-stage (necrotic-like death) was characterized by nucleolar dissolution, nuclear fragmentation, chromatin condensation, and collapse of cytoplasmic structures. After 24 hours post-modeling, the proportion of double-positive cells (porimin + /PI+) and ROS levels significantly increased, as did porimin expression, while mitochondrial membrane potential and ATP levels significantly decreased. The proportion of Annexin V + /PI + double-positive cells and caspase-3 levels showed no significant changes. Results In both in vitro and in vivo studies, oncosis played a crucial role in ehsRM. Pathological and ultrastructural analyses demonstrated cell swelling, structural disarray, mitochondrial damage, and nuclear degeneration. Porimin, CytC, Bax, and caspase-1 expression increased, while Bcl-2 expression decreased. ATP levels decreased, and ROS production increased. In the in vivo study, the proportion of porimin + /PI + double-positive cells and ROS levels significantly increased, while mitochondrial membrane potential and ATP levels significantly decreased. The proportion of Annexin V + /PI + double-positive cells and caspase-3 levels showed no significant changes. Conclusion Oncosis is predominant in ehsRM, involving mitochondrial dysfunction, ATP depletion, and oxidative stress. Show less

Hypoxia is a common feature of solid tumors and is associated with a poor response to anticancer therapies. Hypoxia also induces metabolic changes, such as a switch to glycolysis. This glycolytic switch causes acidification of the tumor microenvironment (TME), thereby attenuating the anticancer immune response. A promising therapeutic strategy to reduce hypoxia and thereby sensitize tumors to irradiation and/or antitumor immune responses is pharmacological inhibition of oxidative phosphorylation (OXPHOS). Several OXPHOS inhibitors (OXPHOSi) have been tested in clinical trials. However, moderate responses and/or substantial toxicity have hampered clinical implementation. OXPHOSi tested in clinical trials inhibit the oxidative metabolism in tumor cells as well as healthy cells. Therefore, new strategies are needed to improve the efficacy of OXPHOSi while minimizing side effects. To enhance the therapeutic window, available OXPHOSi have, for instance, been conjugated to triphenylphosphonium to preferentially target the mitochondria of cancer cells, resulting in increased tumor uptake compared with healthy cells, as cancer cells have a higher mitochondrial membrane potential. However, OXPHOS inhibition also induces reactive oxygen species and subsequent antioxidant responses, which may influence the efficacy of therapies, such as platinum-based chemotherapy and radiotherapy. Here, we review the limitations of the clinically tested OXPHOSi metformin, atovaquone, tamoxifen, BAY 87-2243, and IACS-010759 and the potential of mitochondria-targeted OXPHOSi and their influence on reactive oxygen species production. Furthermore, the effect of the mitochondria-targeting moiety triphenylphosphonium on mitochondria is discussed as it affects mitochondrial bioenergetics. Show less

Mitochondria are dynamic organelles that are essential for cellular energy generation, metabolic regulation, and signal transduction. Their structural complexity enables adaptive responses to diverse physiological demands. In cancer, mitochondria orchestrate multiple cellular processes critical to tumor development. Metabolic reprogramming enables cancer cells to exploit aerobic glycolysis, glutamine metabolism, and lipid alterations, supporting uncontrolled growth, survival, and treatment resistance. Genetic and epigenetic alterations in mitochondrial and nuclear DNA disrupt oxidative phosphorylation, tricarboxylic acid cycle dynamics, and redox homeostasis, driving oncogenic progression. Mitochondrial dysfunction in tumors is highly heterogeneous, influencing disease phenotypes and treatment responses across cancer types. Within the tumor microenvironment, mitochondria profoundly impact immune responses by modulating T-cell survival and function, macrophage polarization, NK cell cytotoxicity, and neutrophil activation. They also mediate stromal cell functions, particularly in cancer-associated fibroblasts and tumor endothelial cells. Although targeting mitochondrial function represents a promising therapeutic strategy, mitochondrial heterogeneity and adaptive resistance mechanisms complicate interventional approaches. Advances in mitochondrial genome editing, proteomics, and circulating mitochondrial DNA analysis have enhanced tumor diagnostic precision. This review synthesizes the developmental landscape of mitochondrial research in cancer, comprehensively summarizing mitochondrial structural dynamics, metabolic plasticity, signaling networks, and interactions with the tumor microenvironment. Finally, we discuss the translational challenges in developing effective mitochondria-based cancer interventions. Show less

Ferredoxins (FDXs) are evolutionarily conserved iron-sulfur (Fe-S) proteins that serve as master regulators of mitochondrial redox homeostasis, governing critical processes including electron transfer, energy metabolism, Fe-S cluster biogenesis, and steroidogenesis. In humans, the mitochondrial isoforms FDX1 and FDX2 exhibit specialized yet complementary functions: FDX1 directs steroidogenesis, protein lipoylation, and copper redox cycling, while FDX2 is a core factor in Fe-S cluster assembly. Crucially, dysregulation of these proteins disrupts mitochondrial integrity, impairs redox balance, and activates multiple programmed cell death (PCD) pathways such as cuproptosis, ferroptosis, apoptosis, and autophagic cell death. This review systematically analyzes their isoform-specific roles in mitochondrial electron transport, Fe-S cluster dynamics, metabolic regulation, and summarizes major advances in understanding how FDX1 and FDX2 orchestrate mitochondrial-PCD crosstalk. The work further examines their critical functions in PCD execution, including FDX1-mediated cuproptosis through Cu+-dependent aggregation of lipoylated proteins and FDX2-deficiency-driven ferroptosis via Fe-S cluster collapse and iron overload. Disease mechanisms across multiple pathologies, including cancer, neurodegeneration, cardiovascular disease, endocrine disorders, and genetic syndromes, are explored, highlighting links to FDX dysfunction, with emerging therapeutic strategies targeting FDXs also addressed. By elucidating the synergistic roles of FDX1 and FDX2 as metabolic-death gatekeepers, this review establishes a foundation for developing isoform-targeted therapies against diverse pathologies. Show less

Mitochondria are essential organelles for many aspects of cellular homeostasis. They play an indispensable role in the development and progression of diseases, particularly cancer which is a major cause of death worldwide. We analyzed the scientific research output on mitochondria and cancer via PubMed and Web of Science over the period 1990-2023. Show less

Ferroptosis is an iron-dependent form of regulated cell death driven by lipid peroxidation. Since the identification of dihydroorotate dehydrogenase (DHODH) as a mitochondrial suppressor of ferroptosis in 2021, increasing evidence has highlighted its role in linking nucleotide metabolism, redox regulation, and tumor progression. We conducted a comprehensive review of publications on DHODH, ferroptosis, and cancer. Relevant studies were analyzed to synthesize mechanistic insights, translational implications, and therapeutic perspectives. DHODH, a flavin-dependent mitochondrial enzyme catalyzing the oxidation of dihydroorotate to orotate, integrates pyrimidine biosynthesis with electron transport chain activity. Beyond its canonical metabolic role, DHODH regenerates ubiquinol (CoQ10H2) to suppress mitochondrial lipid peroxidation and ferroptosis. Elevated DHODH expression in colorectal, hepatocellular, breast, renal, and brain cancers correlates with poor prognosis, therapy resistance, and immune evasion. Pharmacological inhibition of DHODH disrupts pyrimidine synthesis and redox defense, sensitizing GPX4-low tumors to ferroptosis. Preclinical studies demonstrate synergy between DHODH inhibitors and chemotherapy, radiotherapy, or immune checkpoint blockade. Nanoparticle-based delivery systems enhance therapeutic efficacy by simultaneously targeting multiple ferroptosis defense arms while reducing toxicity. DHODH serves as both a metabolic and redox checkpoint in cancer, linking ferroptosis suppression to proliferation and immune escape. Targeting DHODH offers a promising strategy to dismantle cancer resilience, particularly in combination with ferroptosis inducers and immunotherapies. Future research should focus on biomarker-guided stratification, nanomedicine platforms, and clinical translation of DHODH inhibitors. Show less

Sassano et al. identify endoplasmic reticulum–mitochondria contact sites as the intracellular location where phospholipid peroxidation first occurs to promote ferroptosis. Manipulating these contact sites dictates ferroptosis sensitivity in breast cancer. Show less

Ferroptosis is a distinct form of regulated cell death characterized by iron-dependent lipid peroxidation, which plays a critical role in the pathogenesis of various diseases, including ischemic tissue injury, infectious diseases, neurodegenerative disorders, and cancer. The regulatory mechanisms underlying ferroptosis involve a complex interplay of multiple subcellular organelles, orchestrating iron homeostasis, lipid metabolism, and the generation of reactive oxygen species (ROS) that drive peroxidation processes, ultimately leading to membrane damage and cell death. Numerous antioxidant systems play pivotal roles in regulating and preventing ferroptosis, among which the recently identified mitochondrial inner membrane enzyme dihydroorotate dehydrogenase (DHODH) represents a novel therapeutic target for ferroptosis intervention. This systematic review comprehensively elucidates several key cellular defense mechanisms against ferroptosis that counteract ROS-driven peroxidation and operate through distinct subcellular localizations. We particularly focus on delineating the molecular mechanisms by which DHODH regulates ferroptosis, with special emphasis on its role in suppressing mitochondrial lipid peroxidation. Furthermore, we systematically evaluate the therapeutic potential of DHODH inhibitors in oncology, virology, and immune-inflammatory disorders. By integrating ferroptosis biology with DHODH-mediated cytoprotective networks, this review aims to provide mechanistic insights and novel therapeutic strategies for cancer and oxidative stress-related disorders. Show less

Platinum-based drugs are a mainstay in chemotherapy, with traditional forms exerting their work directly on DNA. In recent years, it has been observed that platinum complexes had the potential to induce immunogenic cell death (ICD) and effectively trigger antitumor immune responses. Herein, to obtain novel platinum complexes with chemo-immunological properties, a series of Pt(ΙΙ)-N-heterocyclic carbene (Pt(ΙΙ)-NHC) complexes derived from 4,5-diarylimidazoles were synthesized. Among them, the dominant complex 3f was proved to exhibit better anti-liver cancer capacity compared to cisplatin and oxaliplatin. Complex 3f showed the ability to cause DNA damage by binding to DNA. In addition, it triggered intracellular reactive oxygen species (ROS) generation, affected the function of mitochondria, and blocked cells in G0/G1 phase, ultimately induced apoptosis in liver cancer cells. Furthermore, complex 3f activated endoplasmic reticulum stress (ERS) which promoted the release of damage-associated molecular patterns (DAMPs), induced ICD and dendritic cells (DCs) maturation. Interestingly, complex 3f also upregulated PD-L1, consequently converted "cold tumors" into "hot tumors". Overall, complex 3f had the potential to be regarded as a promising chemoimmunotherapy for the treatment of liver cancer. Show less

Cisplatin and its analogs are extensively utilized as metal-based anticancer agents in clinical settings due to their mechanism of action, which involves targeting genomic double-stranded DNA to induce cytotoxicity in cancer cells. However, the associated severe side effects and DNA damage repair-inducing drug resistance present significant challenges. In recent years, G-quadruplex nucleic acids, formed through the self-assembly of guanine-rich nucleic acid sequences, have emerged as a compelling target for the design of novel anticancer therapeutics. The strategic design of platinum complexes that selectively interact with, stabilize, or cleave G-quadruplex structures represents a promising approach for developing effective anticancer agents to overcome cisplatin resistance. This review will emphasize the advancements made over the past decade in interacting G-quadruplexes with platinum complexes as potential anticancer therapeutics. The ongoing development of platinum complexes spans from targeting nuclear DNA G-quadruplexes to mitochondrial DNA and cytoplasmic RNA G-quadruplexes, evolving from monotherapy approaches, such as chemotherapy and photodynamic therapy, to a combination of radiotherapy, immunotherapy, and more, highlighting the dynamic progress of platinum complexes. At the end, we have summarized 4 points of pending issues in this fast-growing field, which we hope can provide some help to the development of this field. Show less

Ferroptosis, a novel form of regulated cell death induced by the excessive accumulation of lipid peroxidation products, plays a pivotal role in the suppression of tumorigenesis. Two prominent mitochondrial ferroptosis defense systems are glutathione peroxidase 4 (GPX4) and dihydroorotate dehydrogenase (DHODH), both of which are localized within the mitochondria. However, the existence of supplementary cellular defense mechanisms against mitochondrial ferroptosis remains unclear. Our findings unequivocally demonstrate that inactivation of mitochondrial respiratory chain complex I (MCI) induces lipid peroxidation and consequently invokes ferroptosis across GPX4 low-expression cancer cells. However, in GPX4 high expression cancer cells, the MCI inhibitor did not induce ferroptosis, but increased cell sensitivity to ferroptosis induced by the GPX4 inhibitor. Overexpression of the MCI alternative protein yeast NADH-ubiquinone reductase (NDI1) not only quells ferroptosis induced by MCI inhibitors but also confers cellular protection against ferroptosis inducers. Mechanically, MCI inhibitors actuate an elevation in the NADH level while concomitantly diminishing the CoQH2 level. The manifestation of MCI inhibitor-induced ferroptosis can be reversed by supplementation with mitochondrial-specific analogues of CoQH2. Notably, MCI operates in parallel with mitochondrial-localized GPX4 and DHODH to inhibit mitochondrial ferroptosis, but independently of cytosolically localized GPX4 or ferroptosis suppressor protein 1(FSP1). The MCI inhibitor IACS-010759, is endowed with the ability to induce ferroptosis while concurrently impeding tumor proliferation in vivo. Our results identified a ferroptosis defense mechanism mediated by MCI within the mitochondria and suggested a therapeutic strategy for targeting ferroptosis in cancer treatment. Show less

Mitochondria are the energy production centers in cells and have unique genetic information. Due to the irreplaceable function of mitochondria, mitochondrial dysfunction often leads to pathological changes. Mitochondrial dysfunction induces an imbalance between oxidation and antioxidation, mitochondrial DNA (mtDNA) damage, mitochondrial dynamics dysregulation, and changes in mitophagy. It results in oxidative stress due to excessive reactive oxygen species (ROS) generation, which contributes to cell damage and death. Mitochondrial dysfunction can also trigger inflammation through the activation of damage-associated molecular patterns (DAMPs), inflammasomes and inflammatory cells. Besides, mitochondrial alterations in the functional regulation, energy metabolism and genetic stability accompany the aging process, and there has been a lot of evidence suggesting that oxidative stress and inflammation, both of which are associated with mitochondrial dysfunction, are predisposing factors of aging. Therefore, this review hypothesizes that mitochondria serve as central hubs regulating oxidative stress, inflammation, and aging, and their dysfunction contributes to various diseases, including cancers, cardiovascular diseases, neurodegenerative disorders, metabolic diseases, sepsis, ocular pathologies, liver diseases, and autoimmune conditions. Moreover, we outline therapies aimed at various mitochondrial dysfunctions, highlighting their performance in animal models and human trials. Additionally, we focus on the limitations of mitochondrial therapy in clinical applications, and discuss potential future research directions for mitochondrial therapy. Show less

The extent of mitochondrial heterogeneity and the presence of mitochondrial archetypes in cancer remain unknown. Mitochondria play a central role in the metabolic reprogramming that occurs in cancer cells. This process adjusts the activity of metabolic pathways to support growth, proliferation, and survival of cancer cells. Using a panel of colorectal cancer (CRC) cell lines, we revealed extensive differences in their mitochondrial composition, suggesting functional specialisation of these organelles. We differentiated bioenergetic and mitochondrial phenotypes, which point to different strategies used by CRC cells to maintain their sustainability. Moreover, the efficacy of various treatments targeting metabolic pathways was dependent on the respiration and glycolysis levels of cancer cells. Furthermore, we identified metabolites associated with both bioenergetic profiles and cell responses to treatments. The levels of these molecules can be used to predict the therapeutic efficacy of anti-cancer drugs and identify metabolic vulnerabilities of CRC. Our study indicates that the efficacy of CRC therapies is closely linked to mitochondrial status and cellular bioenergetics. Show less

Mitochondria are bilayer membrane organelles with basic metabolic activity. They are considered hubs for biosynthesis, bioenergy, and signaling functions, coordinating major biological pathways. Mitochondria are coupled to the oxidation of fatty acids and pyruvate through electron transport chains and have historically been considered the primary source of cellular energy. Recent studies have depicted that mitochondria are centers that promote inflammatory responses and play a crucial role in combating pathogenic infections. Moreover, Show less

NRF2 is a redox-sensitive transcription factor that activates the expression of phase II detoxifying and antioxidant enzymes. In addition to maintaining redox homeostasis, NRF2 regulates various other processes, including metabolism, stem cell renewal, mitochondrial function, and proteostasis. NRF2 is considered a tumor suppressor because its activation by chemopreventive phytochemicals contributes to the detoxification of oxidants and electrophiles in normal cells. However, aberrant NRF2 activation occurs in cancer due to mutations in the KEAP1/NRF2 pathway, and it contributes to the generation of a tumor microenvironment that favors the proliferation, survival, and chemoresistance of cancer cells. In this review, we present the regulatory mechanisms of NRF2 and discuss how NRF2 activation contributes to chemoresistance. We also explain therapeutic strategies that exploit the vulnerabilities of NRF2-addicted cancer cells, providing NRF2 small-molecule inhibitors along with their mechanisms of action. Show less

Abstract Ferroptosis, a novel form of regulated cell death induced by the excessive accumulation of lipid peroxidation products, plays a pivotal role in the suppression of tumorigenesis. Two prominent mitochondrial ferroptosis defense systems are glutathione peroxidase 4 (GPX4) and dihydroorotate dehydrogenase (DHODH), both of which are localized within the mitochondria. However, the existence of supplementary cellular defense mechanisms against mitochondrial ferroptosis remains unclear. Our findings unequivocally demonstrate that inactivation of mitochondrial respiratory chain complex I (MCI) induces lipid peroxidation and consequently invokes ferroptosis across GPX4 low-expression cancer cells. However, in GPX4 high expression cancer cells, the MCI inhibitor did not induce ferroptosis, but increased cell sensitivity to ferroptosis induced by the GPX4 inhibitor. Overexpression of the MCI alternative protein yeast NADH-ubiquinone reductase (NDI1) not only quells ferroptosis induced by MCI inhibitors but also confers cellular protection against ferroptosis inducers. Mechanically, MCI inhibitors actuate an elevation in the NADH level while concomitantly diminishing the CoQH2 level. The manifestation of MCI inhibitor-induced ferroptosis can be reversed by supplementation with mitochondrial-specific analogues of CoQH2. Notably, MCI operates in parallel with mitochondrial-localized GPX4 and DHODH to inhibit mitochondrial ferroptosis, but independently of cytosolically localized GPX4 or ferroptosis suppressor protein 1(FSP1). The MCI inhibitor IACS-010759, is endowed with the ability to induce ferroptosis while concurrently impeding tumor proliferation in vivo. Our results identified a ferroptosis defense mechanism mediated by MCI within the mitochondria and suggested a therapeutic strategy for targeting ferroptosis in cancer treatment. Show less

Studies by microbiologists in the 1970s provided robust estimates for the energy supply and demand of a prokaryotic cell. The amount of ATP needed to support growth was calculated from the chemical composition of the cell and known enzymatic pathways that synthesize its constituents from known substrates in culture. Starting in 2015, geneticists and evolutionary biologists began investigating the bioenergetic role of mitochondria at eukaryote origin and energy in metazoan evolution using their own, widely trusted-but hitherto unvetted-model for the costs of growth in terms of ATP per cell. The more recent model contains, however, a severe and previously unrecognized error that systematically overestimates the ATP cost of amino acid synthesis up to 200-fold. The error applies to all organisms studied by such models and leads to conspicuously false inferences, for example that the synthesis of an average amino acid in humans requires 30 ATP, which no biochemistry textbook will confirm. Their ATP 'cost' calculations would require that E. coli obtains ~100 ATP per glucose and that mammals obtain ~240 ATP per glucose, untenable propositions that invalidate and void all evolutionary inferences so based. By contrast, established methods for estimating the ATP cost of microbial growth show that the first mitochondrial endosymbionts could have easily doubled the host's available ATP pool, provided (i) that genes for growth on environmental amino acids were transferred from the mitochondrial symbiont to the archaeal host, and (ii) that the host for mitochondrial origin was an autotroph using the acetyl-CoA pathway. Stated in simple terms, the significance of these findings are this: Life is a chemical reaction. It requires energy release in order to proceed. The currency of energy in cells is adenosine triphosphate, ATP. Five decades ago, microbiologists were able to measure and understand the amount of ATP that cells require to grow. New studies by evolutionary biologists have appeared in the meantime that brush aside the older microbiological findings, using their own methods to calculate the ATP cost of growth instead. Science is, however, an imperfect undertaking. The new studies contain a major error, similar to conflating centimeters with yards. The error affects many publications and their conclusions. Using the old methods, we can still meaningfully study the role of energy in evolution, including the origin of complex, nucleus-bearing cells. Show less

Redox signaling acts as a critical mediator in the dynamic interactions between organisms and their external environment, profoundly influencing both the onset and progression of various diseases. Under physiological conditions, oxidative free radicals generated by the mitochondrial oxidative respiratory chain, endoplasmic reticulum, and NADPH oxidases can be effectively neutralized by NRF2-mediated antioxidant responses. These responses elevate the synthesis of superoxide dismutase (SOD), catalase, as well as key molecules like nicotinamide adenine dinucleotide phosphate (NADPH) and glutathione (GSH), thereby maintaining cellular redox homeostasis. Disruption of this finely tuned equilibrium is closely linked to the pathogenesis of a wide range of diseases. Recent advances have broadened our understanding of the molecular mechanisms underpinning this dysregulation, highlighting the pivotal roles of genomic instability, epigenetic modifications, protein degradation, and metabolic reprogramming. These findings provide a foundation for exploring redox regulation as a mechanistic basis for improving therapeutic strategies. While antioxidant-based therapies have shown early promise in conditions where oxidative stress plays a primary pathological role, their efficacy in diseases characterized by complex, multifactorial etiologies remains controversial. A deeper, context-specific understanding of redox signaling, particularly the roles of redox-sensitive proteins, is critical for designing targeted therapies aimed at re-establishing redox balance. Emerging small molecule inhibitors that target specific cysteine residues in redox-sensitive proteins have demonstrated promising preclinical outcomes, setting the stage for forthcoming clinical trials. In this review, we summarize our current understanding of the intricate relationship between oxidative stress and disease pathogenesis and also discuss how these insights can be leveraged to optimize therapeutic strategies in clinical practice. Show less

BACKGROUND: Globally, the onset and progression of multiple human diseases are associated with mitochondrial dysfunction and dysregulation of Ca2+ uptake dynamics mediated by the mitochondrial calcium uniporter (MCU) complex, which plays a key role in mitochondrial dysfunction. Despite relevant studies, the underlying pathophysiological mechanisms have not yet been fully elucidated. AIM OF REVIEW: This article provides an in-depth analysis of the current research status of the MCU complex, focusing on its molecular composition, regulatory mechanisms, and association with diseases. In addition, we conducted an in-depth analysis of the regulatory effects of agonists, inhibitors, and traditional Chinese medicine (TCM) monomers on the MCU complex and their application prospects in disease treatment. From the perspective of medicinal chemistry, we conducted an in-depth analysis of the structure-activity relationship between these small molecules and MCU and deduced potential pharmacophores and binding pockets. Simultaneously, key structural domains of the MCU complex in Homo sapiens were identified. We also studied the functional expression of the MCU complex in Drosophila, Zebrafish, and Caenorhabditis elegans. These analyses provide a basis for exploring potential treatment strategies targeting the MCU complex and provide strong support for the development of future precision medicine and treatments. KEY SCIENTIFIC CONCEPTS OF REVIEW: The MCU complex exhibits varying behavior across different tissues and plays various roles in metabolic functions. It consists of six MCU subunits, an essential MCU regulator (EMRE), and solute carrier 25A23 (SLC25A23). They regulate processes, such as mitochondrial Ca2+ (mCa2+) uptake, mitochondrial adenosine triphosphate (ATP) production, calcium dynamics, oxidative stress (OS), and cell death. Regulation makes it a potential target for treating diseases, especially cardiovascular diseases, neurodegenerative diseases, inflammatory diseases, metabolic diseases, and tumors. Show less

Rhenium(I) tricarbonyl complexes are widely studied for their cell imaging properties and anti-cancer and anti-microbial activities, but the complexes with S-donor ligands remain relatively unexplored. A series of six fac-[Re(NN)(CO)3(SR)] complexes, where (NN) is 2,2′-bipyridyl (bipy) or 1,10-phenanthroline (phen), and RSH is a series of thiocarboxylic acid methyl esters, have been synthesized and characterized. Cellular uptake and anti-proliferative activities of these complexes in human breast cancer cell lines (MDA-MB-231 and MCF-7) were generally lower than those of the previously described fac-[Re(NN)(CO)3(OH2)]+ complexes; however, one of the complexes, fac-[Re(CO)3(phen)(SC(Ph)CH2C(O)OMe)] (3b), was active (IC50 ∼ 10 μM at 72 h treatment) in thiol-depleted MDA-MB-231 cells. Moreover, unlike fac-[Re(CO)3(phen)(OH2)]+, this complex did not lose activity in the presence of extracellular glutathione. Taken together these properties show promise for further development of 3b and its analogues as potential anti-cancer drugs for co-treatment with thiol-depleting agents. Conversely, the stable and non-toxic complex, fac-[Re(bipy)(CO)3(SC(Me)C(O)OMe)] (1a), predominantly localized in the lysosomes of MDA-MB-231 cells, as shown by live cell confocal microscopy (λex = 405 nm, λem = 470–570 nm). It is strongly localized in a subset of lysosomes (25 μM Re, 4 h treatment), as shown by co-localization with a Lysotracker dye. Longer treatment times with 1a (25 μM Re for 48 h) resulted in partial migration of the probe into the mitochondria, as shown by co-localization with a Mitotracker dye. These properties make complex 1a an attractive target for further development as an organelle probe for multimodal imaging, including phosphorescence, carbonyl tag for vibrational spectroscopy, and Re tag for X-ray fluorescence microscopy. Show less

AbstractMitochondria, recognized as the cellular powerhouses, are indispensable organelles responsible for crucial cellular processes, such as energy metabolism, material synthesis, and signaling transduction. Their intricate involvement in a broad spectrum of diseases, particularly cancer, has propelled the exploration of mitochondria‐targeting treatment as a promising strategy for cancer therapy. Since the groundbreaking discovery of cisplatin, the trajectory of research on the development of metal complexes have been marked by continuous advancement, giving rise to a diverse array of metallodrugs characterized by variations in ligand types, metal center properties, and oxidation states. By specifically targeting mitochondria, these metallodrugs exhibit the remarkable ability to elicit various programmed cell death pathways, encompassing apoptosis, autophagy, and ferroptosis. This review primarily focuses on recent developments in transition metal‐based mitochondria‐targeting agents, offering a comprehensive exploration of their capacity to induce distinct cell death modes. The aim is not only to disseminate knowledge but also to stimulate an active field of research toward new clinical applications and novel anticancer mechanisms. Show less

“Reprogramming of energy metabolism” was first considered an emerging hallmark of cancer in 2011 by Hanahan & Weinberg and is now considered a core hallmark of cancer. Mitochondria are the hubs of metabolism, crucial for energetic functions and cellular homeostasis. The mitochondrion’s bacterial origin and preservation of their own genome, which encodes proteins and RNAs essential to their function, make them unique organelles. Successful generation of mitochondrial gene products requires coordinated functioning of the mitochondrial ‘central dogma,’ encompassing all steps necessary for mtDNA to yield mitochondrial proteins. Each of these processes has several levels of regulation, including mtDNA accessibility and protection through mtDNA packaging and epigenetic modifications, mtDNA copy number through mitochondrial replication, mitochondrial transcription through mitochondrial transcription factors, and mitochondrial translation through mitoribosome formation. Deregulation of these mitochondrial processes in the context of cancers has only recently been appreciated, with most studies being correlative in nature. Nonetheless, numerous significant associations of the mitochondrial central dogma with pro-tumor phenotypes have been documented. Several studies have even provided mechanistic insights and further demonstrated successful pharmacologic targeting strategies. Based on the emergent importance of mitochondria for cancer biology and therapeutics, it is becoming increasingly important that we gain an understanding of the underpinning mechanisms so they can be successfully therapeutically targeted. It is expected that this mechanistic understanding will result in mitochondria-targeting approaches that balance anticancer potency with normal cell toxicity. This review will focus on current evidence for the dysregulation of mitochondrial gene expression in cancers, as well as therapeutic opportunities on the horizon. Show less

The brain’s high demand for energy necessitates tightly regulated metabolic pathways to sustain physiological activity. Glucose, the primary energy substrate, undergoes complex metabolic transformations, with mitochondria playing a central role in ATP production via oxidative phosphorylation. Dysregulation of this metabolic interplay is implicated in Alzheimer’s disease (AD), where compromised glucose metabolism, oxidative stress, and mitochondrial dysfunction contribute to disease progression. This review explores the intricate bioenergetic crosstalk between astrocytes and neurons, highlighting the function of mitochondrial uncoupling proteins (UCPs), particularly UCP4, as important regulators of brain metabolism and neuronal function. Predominantly expressed in the brain, UCP4 reduces the membrane potential in the inner mitochondrial membrane, thereby potentially decreasing the generation of reactive oxygen species. Furthermore, UCP4 mitigates mitochondrial calcium overload and sustains cellular ATP levels through a metabolic shift from mitochondrial respiration to glycolysis. Interestingly, the levels of the neuronal UCPs, UCP2, 4 and 5 are significantly reduced in AD brain tissue and a specific UCP4 variant has been associated to an increased risk of developing AD. Few studies modulating the expression of UCP4 in astrocytes or neurons have highlighted protective effects against neurodegeneration and aging, suggesting that pharmacological strategies aimed at activating UCPs, such as protonophoric uncouplers, hold promise for therapeutic interventions in AD and other neurodegenerative diseases. Despite significant advances, our understanding of UCPs in brain metabolism remains in its early stages, emphasizing the need for further research to unravel their biological functions in the brain and their therapeutic potential. Show less

Cuproptosis is a newly identified form of cell death induced by excessive copper (Cu) accumulation within cells. Mechanistically, cuproptosis results from Cu-induced aggregation of dihydrolipoamide S-acetyltransferase, correlated with the mitochondrial tricarboxylic acid cycle and the loss of iron–sulfur cluster proteins, ultimately resulting in proteotoxic stress and triggering cell death. Recently, cuproptosis has garnered significant interest in tumor research due to its potential as a crucial therapeutic strategy against cancer. In this review, we summarized the cellular and molecular mechanisms of cuproptosis and its relationship with other types of cell death. Additionally, we reviewed the current drugs or strategies available to induce cuproptosis in tumor cells, including Cu ionophores, small compounds, and nanomedicine. Furthermore, we targeted cell metabolism and specific regulatory genes in cancer therapy to enhance tumor sensitivity to cuproptosis. Finally, we discussed the feasibility of targeting cuproptosis to overcome tumor chemotherapy and immunotherapy resistance and suggested future research directions. This study suggested that targeting cuproptosis could open new avenues for developing tumor therapy. Show less