bims-mibica 2025-02-23 papers

bims-mibica

Biomed News

on Mitochondrial bioenergetics in cancer

Issue of 2025–02–23
23 papers selected by
Kelsey Fisher-Wellman, Wake Forest University

Pro-inflammatory macrophages produce mitochondria-derived superoxide by reverse electron transport at complex I that regulates IL-1β release during NLRP3 inflammasome activation.
Hexokinase detachment from mitochondria drives the Warburg effect to support compartmentalized ATP production.
Mdm38/LETM1 couples ion homeostasis and proteostatic mechanisms in the inner mitochondrial membrane.
Lon protease 1-mediated metabolic reprogramming promotes the progression of prostate cancer.
Exploring the proton transport mechanism of the mitochondrial ADP/ATP carrier: FA-cycling hypothesis and beyond.
Putting the brakes on mitochondrial fusion to prevent escape of mitochondrial DNA.
How are mitochondrial nucleoids trafficked?
A Quantitative Approach to Mapping Mitochondrial Specialization and Plasticity.
CDK6 kinase inhibition unmasks metabolic dependencies in BCR::ABL1+ leukemia.
Anaplerosis by medium-chain fatty acids through complex interplay with glucose and glutamine metabolism.
Dual regulation of mitochondrial fusion by Parkin-PINK1 and OMA1.
Uridine Metabolism as a Targetable Metabolic Achilles' Heel for chemo-resistant B-ALL.
M8OI toxicity is associated with an inhibition of ubiquinone reduction by complex I in the mitochondrial electron transport chain.
Mitochondrial metabolism is rapidly re-activated in mature neutrophils to support stimulation-induced response.
Targeting both the enzymatic and non-enzymatic functions of DHODH as a therapeutic vulnerability in c-Myc-driven cancer.
Ruxolitinib as a novel therapeutic agent targeting mitochondrial function and chemo-resistance in nasopharyngeal carcinoma.
STAT1 inhibition promotes oxidative stress to sustain leukemia stem cell maintenance.
Cooperative nutrient scavenging is an evolutionary advantage in cancer.
Ketogenic diet suppresses colorectal cancer through the gut microbiome long chain fatty acid stearate.
Heightened sensitivity to adverse effects of metformin in mtDNA mutant patient cells.
High Glucose Contribution to the TCA Cycle Is a Feature of Aggressive Non-Small Cell Lung Cancer in Patients.
ONC201-Derived Tetrahydropyridopyrimidindiones as Powerful ClpP Protease Activators to Tackle Diffuse Midline Glioma.
Intratumour oxidative hotspots provide a niche for cancer cell dissemination.

Nat Metab. 2025 Feb 19.

Pro-inflammatory macrophages produce mitochondria-derived superoxide by reverse electron transport at complex I that regulates IL-1β release during NLRP3 inflammasome activation.

Alva M Casey, Dylan G Ryan, Hiran A Prag, Suvagata Roy Chowdhury, Eloïse Marques, Keira Turner, Anja V Gruszczyk, Ming Yang, Dane M Wolf, Jan Lj Miljkovic, Joyce Valadares, Patrick F Chinnery, Richard C Hartley, Christian Frezza, Julien Prudent, Michael P Murphy.

Macrophages stimulated by lipopolysaccharide (LPS) generate mitochondria-derived reactive oxygen species (mtROS) that act as antimicrobial agents and redox signals; however, the mechanism of LPS-induced mitochondrial superoxide generation is unknown. Here we show that LPS-stimulated bone-marrow-derived macrophages produce superoxide by reverse electron transport (RET) at complex I of the electron transport chain. Using chemical biology and genetic approaches, we demonstrate that superoxide production is driven by LPS-induced metabolic reprogramming, which increases the proton motive force (∆p), primarily as elevated mitochondrial membrane potential (Δψm) and maintains a reduced CoQ pool. The key metabolic changes are repurposing of ATP production from oxidative phosphorylation to glycolysis, which reduces reliance on F1FO-ATP synthase activity resulting in a higher ∆p, while oxidation of succinate sustains a reduced CoQ pool. Furthermore, the production of mtROS by RET regulates IL-1β release during NLRP3 inflammasome activation. Thus, we demonstrate that ROS generated by RET is an important mitochondria-derived signal that regulates macrophage cytokine production.

DOI: https://doi.org/10.1038/s42255-025-01224-x
bioRxiv. 2025 Feb 08. pii: 2025.02.07.637120. [Epub ahead of print]

Hexokinase detachment from mitochondria drives the Warburg effect to support compartmentalized ATP production.

Kimberly S Huggler, Carlos A Mellado Fritz, Kyle M Flickinger, Gavin R Chang, Meghan F McGuire, Jason R Cantor.

Hexokinase (HK) catalyzes the synthesis of glucose-6-phosphate, marking the first committed step of glucose metabolism. Most cancer cells express two homologous isoforms (HK1 and HK2) that can each bind to the outer mitochondrial membrane (OMM). CRISPR screens across hundreds of cancer cell lines indicate that both are dispensable for cell growth in traditional culture media. By contrast, HK2 deletion impairs cell growth in Human Plasma-Like Medium (HPLM). Here, we find that HK2 is required to maintain sufficient cytosolic (OMM-detached) HK activity under conditions that enhance HK1 binding to the OMM. Notably, OMM-detached rather than OMM-docked HK promotes "aerobic glycolysis" (Warburg effect), an enigmatic phenotype displayed by most proliferating cells. We show that several proposed theories for this phenotype cannot explain the HK2 dependence and instead find that HK2 deletion severely impairs glycolytic ATP production with little impact on total ATP yield for cells in HPLM. Our results reveal a basis for conditional HK2 essentiality and suggest that demand for compartmentalized ATP synthesis underlies the Warburg effect.

DOI: https://doi.org/10.1101/2025.02.07.637120
bioRxiv. 2025 Jan 30. pii: 2025.01.30.635785. [Epub ahead of print]

Mdm38/LETM1 couples ion homeostasis and proteostatic mechanisms in the inner mitochondrial membrane.

Iryna Bohovych, Gabriella Menezes da Silva, Saieeda Fabia Ali, Emma J Bergmeyer, Edward M Germany, Adarsh Mayank, James A Wohlschlegel, Jason C Casler, Muhammad Arifur Rahman, Taras Y Nazarko, Maureen Tarsio, Takuya Shiota, Laura L Lackner, Steven M Claypool, Patricia M Kane, Antoni Barrientos, Oleh Khalimonchuk.

The mitochondrial inner membrane is among the most protein-dense cellular membranes. Its functional integrity is maintained through a concerted action of several conserved mechanisms that are far from clear. Here, using the baker's yeast model, we functionally characterize Mdm38/LETM1, a disease-related protein implicated in mitochondrial translation and ion homeostasis, although the molecular basis of these connections remains elusive. Our findings reveal a novel role for Mdm38 in maintaining protein homeostasis within the inner membrane. Specifically, we demonstrate that Mdm38 is required for mitochondrial iron homeostasis and for signaling iron bioavailability from mitochondria to vacuoles. These processes are linked to the m- AAA quality control protease, whose unrestrained activity disrupts the assembly and stability of respiratory chain complexes in Mdm38-deficient cells. Our study highlights the central role of Mdm38 in mitochondrial biology and reveals how it couples proteostatic mechanisms to ion homeostasis across subcellular compartments.

DOI: https://doi.org/10.1101/2025.01.30.635785
Cell Death Dis. 2025 Feb 19. 16(1): 116

Lon protease 1-mediated metabolic reprogramming promotes the progression of prostate cancer.

Mengfei Yao, Xingming Zhang, Tianqi Wu, Tao Feng, Xiaojie Bian, Mierxiati Abudurexiti, Wenfeng Wang, Guohai Shi, Gong-Hong Wei, Qin Zhang, Xiangyun Li, Gang Feng, Leilei Du, Jianhua Wang.

Lon protease 1 (LONP1) is an ATP-dependent protease located in the mitochondrial matrix and plays a crucial role in regulating mitochondrial proteostasis, metabolism, and cellular stress responses et al. Aberrant LONP1 expression has been found in the progression of various tumors; however, the role and molecular mechanisms of LONP1 in prostate cancer (PCa) remain poorly understood. Here we show that overexpression of LONP1 is closely related to adverse clinic pathological features and poor prognosis in PCa patients. Mechanistically, the findings reveal that LONP1 is implicated in modulating the metabolic switch from oxidative phosphorylation (OXPHOS) to aerobic glycolysis, thereby promoting tumor proliferation, invasion, and metastasis both in vitro and in vivo. Meanwhile, we prove that LONP1 as a protease directly targets mitochondrial pyruvate carrier 1 (MPC1), a key metabolic protein in the process of glycolysis, and enhances its degradation, which in turn suppresses tricarboxylic acid (TCA) cycle and ultimately promotes the progression of PCa. Furthermore, using PCa in cancer-prone mice homozygous for a prostate-targeted conditional Pten knockout and Lonp1 knockin, we integrate transcriptomic and proteomic analyses of prostate tumors, upon which reveals that Lonp1 overexpression results in a significant downregulation of NADH: ubiquinone oxidoreductase activity, consequently impeding the electron transfer process and mitochondrial ATP synthesis, associated with metastasis of PCa. Collectively, our results highlight that metabolic reprogramming induced by LONP1 in PCa is closely coupled with disease progression, suggesting that targeting the LONP1-mediated cascade in the mitochondrial may provide therapeutic potential for PCa disease.

DOI: https://doi.org/10.1038/s41419-025-07449-8
Protein Sci. 2025 Mar;34(3): e70047

Exploring the proton transport mechanism of the mitochondrial ADP/ATP carrier: FA-cycling hypothesis and beyond.

Elena E Pohl, Mario Vazdar, Jürgen Kreiter.

  The mitochondrial ADP/ATP carrier (AAC, ANT), a member of the SLC25 family of solute carriers, plays a critical role in transporting purine nucleotides (ATP and ADP) as well as protons across the inner mitochondrial membrane. However, the precise mechanism and physiological significance of proton transport by ADP/ATP carrier remain unclear. Notably, the presence of uncouplers-such as long-chain fatty acids (FA) or artificial compounds like dinitrophenol (DNP)-is essential for this process. We explore two potential mechanisms that describe ADP/ATP carrier as either (i) a proton carrier that functions in the presence of FA or DNP, or (ii) an anion transporter (FA- or DNP). In the latter case, the proton is translocated by the neutral form of FA, which carries it from the matrix to the intermembrane space (FA-cycling hypothesis). Our recent results support this hypothesis. We describe a four-step mechanism for the "sliding" of the FA anion from the matrix to the mitochondrial intermembrane space and discuss a possible generalization of this mechanism to other SLC25 carriers.

Keywords:  MD simulations; bilayer lipid membranes; membrane proteins; mitochondrial transporter; reconstituted protein; uncoupling protein

DOI:  https://doi.org/10.1002/pro.70047
Nature. 2025 Feb 19.

Putting the brakes on mitochondrial fusion to prevent escape of mitochondrial DNA.

Kate McArthur, Michael T Ryan.



Keywords:  Cell biology

DOI:  https://doi.org/10.1038/d41586-025-00303-z
Trends Cell Biol. 2025 Feb 20. pii: S0962-8924(24)00272-1. [Epub ahead of print]

How are mitochondrial nucleoids trafficked?

Josefa Macuada, Isidora Molina-Riquelme, Verónica Eisner.

  Mitochondria harbor their own DNA (mtDNA), which codifies essential proteins of the oxidative phosphorylation (OXPHOS) system and locally feeds them to their surrounding inner mitochondrial membrane (IMM), according to the 'sphere of influence' theory. mtDNA is compacted into nucleoids, which are tethered to the IMM and distributed throughout the mitochondrial network. Some nucleoid subpopulations present distinct intramitochondrial positioning during fission and their correct positioning is associated with mtDNA segregation and selective degradation. This opinion article focuses on different mechanisms that could control nucleoid positioning through intramitochondrial trafficking, either by cristae reshaping or by intercompartment-driven mechanisms involving the mitochondrial membranes and extramitochondrial elements. Understanding nucleoid trafficking promises insights into mitochondrial dysfunction in pathologies with mtDNA distribution and segregation issues.

Keywords:  cristae reshaping; mitochondrial nucleoid; mtDNA inheritance; nucleoid dynamics; sphere of influence

DOI:  https://doi.org/10.1016/j.tcb.2024.12.007
bioRxiv. 2025 Feb 08. pii: 2025.02.03.635951. [Epub ahead of print]

A Quantitative Approach to Mapping Mitochondrial Specialization and Plasticity.

Anna S Monzel, Jack Devine, Darshana Kapri, Jose Antonio Enriquez, Caroline Trumpff, Martin Picard.

Mitochondria are a diverse family of organelles that specialize to accomplish complimentary functions 1-3 . All mitochondria share general features, but not all mitochondria are created equal 4 .Here we develop a quantitative pipeline to define the degree of molecular specialization among different mitochondrial phenotypes - or mitotypes . By distilling hundreds of validated mitochondrial genes/proteins into 149 biologically interpretable MitoPathway scores (MitoCarta 3.0 5 ) the simple mitotyping pipeline allows investigators to quantify and interpret mitochondrial diversity and plasticity from transcriptomics or proteomics data across a variety of natural and experimental contexts. We show that mouse and human multi-organ mitotypes segregate along two main axes of mitochondrial specialization, contrasting anabolic (liver) and catabolic (brain) tissues. In cultured primary human fibroblasts exhibiting robust time-dependent and treatment-induced metabolic plasticity 6-8 , we demonstrate how the mitotype of a given cell type recalibrates i) over time in parallel with hallmarks of aging, and ii) in response to genetic, pharmacological, and metabolic perturbations. Investigators can now use MitotypeExplorer.org and the associated code to visualize, quantify and interpret the multivariate space of mitochondrial biology.

DOI: https://doi.org/10.1101/2025.02.03.635951
Cell Death Dis. 2025 Feb 18. 16(1): 107

CDK6 kinase inhibition unmasks metabolic dependencies in BCR::ABL1+ leukemia.

Lisa Scheiblecker, Thorsten Klampfl, Eszter Doma, Sofie Nebenfuehr, Omar Torres-Quesada, Sophie Strich, Gerwin Heller, Daniela Werdenich, Waltraud Tschulenk, Markus Zojer, Florian Bellutti, Alessia Schirripa, Sabine Zöchbauer-Müller, Peter Valent, Ingrid Walter, Eduard Stefan, Veronika Sexl, Karoline Kollmann.

Metabolic reprogramming and cell cycle deregulation are hallmarks of cancer cells. The cell cycle kinase CDK6 has recently been implicated in a wide range of hematopoietic malignancies. We here investigate the role of CDK6 in the regulation of cellular metabolism in BCR::ABL1+ leukemic cells. Our study, using gene expression data and ChIP-Seq analysis, highlights the contribution of CDK6 kinase activity in the regulation of oxidative phosphorylation. Our findings imply a competition for promoter interaction of CDK6 with the master regulator of mitochondrial respiration, NRF-1. In line, cells lacking kinase active CDK6 display altered mitochondria morphology with a defective electron transport chain. The enhanced cytoplasm/mitochondria ATP ratio paralleled by high pyruvate and lactate levels indicate a metabolic switch to glycolysis. Accordingly, combinatorial treatment of leukemic cells including imatinib resistant cells with the CDK4/6 inhibitor palbociclib and the glycolysis inhibitor 2-deoxyglucose (2-DG) enhanced apoptosis, while blocking cell proliferation in leukemic cells. These data may open a new therapeutic avenue for hematologic malignancies with high CDK6 expression by exploiting metabolic vulnerabilities unmasked by blocking CDK6 kinase activity that might even be able to overcome imatinib resistance.

DOI: https://doi.org/10.1038/s41419-025-07434-1
J Biol Chem. 2025 Feb 13. pii: S0021-9258(25)00155-3. [Epub ahead of print] 108307

Anaplerosis by medium-chain fatty acids through complex interplay with glucose and glutamine metabolism.

Hannah M German, Jolita Ciapaite, Nanda M Verhoeven-Duif, Judith J M Jans.

  The constant replenishment of tricarboxylic acid (TCA) cycle intermediates, or anaplerosis, is crucial to ensure optimal TCA cycle activity in times of high biosynthetic demand. In inborn metabolic diseases, anaplerosis is often affected, leading to impaired TCA cycle flux and ATP production. In these cases, anaplerotic compounds can be a therapy option. Triheptanoin, a triglyceride containing three heptanoate chains, is thought to be anaplerotic through production of propionyl- and acetyl-CoA. However, the precise mechanism underlying its anaplerotic action remains poorly understood. In this study, we performed a comprehensive in vitro analysis of heptanoate metabolism and compared it to that of octanoate, an even-chain fatty acid which only provides acetyl-CoA. Using stable isotope tracing, we demonstrate that both heptanoate and octanoate contribute carbon to the TCA cycle in HEK293T cells, confirming direct anaplerosis. Furthermore, by using labeled glucose and glutamine, we show that heptanoate and octanoate decrease the contribution of glucose-derived carbon and increase the influx of glutamine-derived carbon into the TCA cycle. Our findings also point towards a change in redox homeostasis, indicated by an increased NAD+/NADH ratio, accompanied by a decreased lactate/pyruvate ratio and increased de novo serine biosynthesis. Taken together, these results highlight the broad metabolic effects of heptanoate and octanoate supplementation, suggesting that therapeutic efficacy may strongly depend on specific disease pathophysiology. Furthermore, they underline the need for careful selection of fatty acid compound and concentration to optimize anaplerotic action.

Keywords:  Anaplerosis; fatty acids; isotopic tracer; mass spectrometry (MS); metabolic disease; metabolomics; redox regulation

DOI:  https://doi.org/10.1016/j.jbc.2025.108307
Nature. 2025 Feb 19.

Dual regulation of mitochondrial fusion by Parkin-PINK1 and OMA1.

Tatsuya Yamada, Arisa Ikeda, Daisuke Murata, Hu Wang, Cissy Zhang, Pratik Khare, Yoshihiro Adachi, Fumiya Ito, Pedro M Quirós, Seth Blackshaw, Carlos López-Otín, Thomas Langer, David C Chan, Anne Le, Valina L Dawson, Ted M Dawson, Miho Iijima, Hiromi Sesaki.

Mitochondrial stress pathways protect mitochondrial health from cellular insults1-8. However, their role under physiological conditions is largely unknown. Here, using 18 single, double and triple whole-body and tissue-specific knockout and mutant mice, along with systematic mitochondrial morphology analysis, untargeted metabolomics and RNA sequencing, we discovered that the synergy between two stress-responsive systems-the ubiquitin E3 ligase Parkin and the metalloprotease OMA1-safeguards mitochondrial structure and genome by mitochondrial fusion, mediated by the outer membrane GTPase MFN1 and the inner membrane GTPase OPA1. Whereas the individual loss of Parkin or OMA1 does not affect mitochondrial integrity, their combined loss results in small body size, low locomotor activity, premature death, mitochondrial abnormalities and innate immune responses. Thus, our data show that Parkin and OMA1 maintain a dual regulatory mechanism that controls mitochondrial fusion at the two membranes, even in the absence of extrinsic stress.

DOI: https://doi.org/10.1038/s41586-025-08590-2
bioRxiv. 2025 Jan 30. pii: 2025.01.27.635108. [Epub ahead of print]

Uridine Metabolism as a Targetable Metabolic Achilles' Heel for chemo-resistant B-ALL.

Yuxuan Liu, Haowen Jiang, Jingjing Liu, Lucille Stuani, Milton Merchant, Astraea Jager, Abhishek Koladiya, Ti-Cheng Chang, Pablo Domizi, Jolanda Sarno, Tim Keyes, Dorra Jedoui, Ao Wang, Jodie Meng, Felix Hartmann, Sean C Bendall, Min Huang, Norman J Lacayo, Kathleen M Sakamoto, Charles G Mullighan, Mignon Loh, Jiyang Yu, Jun Yang, Jiangbin Ye, Kara L Davis.

Relapse continues to limit survival for patients with B-cell acute lymphoblastic leukemia (B-ALL). Previous studies have independently implicated activation of B-cell developmental signaling pathways and increased glucose consumption with chemo-resistance and relapse risk. Here, we connect these observations, demonstrating that B-ALL cells with active signaling, defined by high expression of phosphorylated ribosomal protein S6 ("pS6+ cells"), are metabolically unique and glucose dependent. Isotope tracing and metabolic flux analysis confirm that pS6+ cells are highly glycolytic and notably sensitive to glucose deprivation, relying on glucose for de novo nucleotide synthesis. Uridine, but not purine or pyrimidine, rescues pS6+ cells from glucose deprivation, highlighting uridine is essential for their survival. Active signaling in pS6+ cells drives uridine production through activating phosphorylation of carbamoyl phosphate synthetase (CAD), the enzyme catalyzing the initial steps of uridine synthesis. Inhibition of signaling abolishes glucose dependency and CAD phosphorylation in pS6+ cells. Primary pS6+ cells demonstrate high expression of uridine synthesis proteins, including dihydroorotate dehydrogenase (DHODH), the rate-limiting catalyst of de novo uridine synthesis. Gene expression demonstrates that increased expression of DHODH is associated with relapse and inferior event-free survival after chemotherapy. Further, the majority of B-ALL genomic subtypes demonstrate activity of DHODH. Inhibiting DHODH using BAY2402232 effectively kills pS6+ cells in vitro , with its IC50 correlated with the strength of pS6 signaling across 14 B-ALL cell lines and patient-derived xenografts (PDX). In vivo DHODH inhibition prolongs survival and decreases leukemia burden in pS6+ B-ALL cell line and PDX models. These findings link active signaling to uridine dependency in B-ALL cells and an associated risk of relapse. Targeting uridine synthesis through DHODH inhibition offers a promising therapeutic strategy for chemo-resistant B-ALL as a novel therapeutic approach for resistant disease.

DOI: https://doi.org/10.1101/2025.01.27.635108
Chemosphere. 2025 Feb 18. pii: S0045-6535(25)00155-9. [Epub ahead of print]374 144213

M8OI toxicity is associated with an inhibition of ubiquinone reduction by complex I in the mitochondrial electron transport chain.

Tarek M Abdelghany, Jessica Bosak, Alistair C Leitch, Alex Charlton, Lanyu Fan, Fahad A Aljehani, Omar H Alkhathami, Shireen A Hedya, Satomi Miwa, Agnieszka K Bronowska, Judy Hirst, Matthew C Wright.

  Methylimidazolium ionic liquids (MILs) are solvents used in an increasing variety of industrial applications. Recent studies identified the 8C MIL (M8OI) contaminating the environment, detected exposure in humans and proposed M8OI to be a potential trigger for the autoimmune liver disease primary biliary cholangitis (PBC). To gain a better understanding of any PBC trigger mechanism(s), the interaction of M8OI with mitochondria has been examined. M8OI inhibited oxygen consumption in intact cells and induced cell death (IC50%-10 μM). Results from permeabilized cells indicated M8OI inhibits the mitochondrial electron transport chain at complex I, not complexes II, III or IV. Accordingly, succinate supported mitochondrial oxygen consumption and reduced cell death in the presence of M8OI. M8OI inhibited NADH oxidation by both mitochondrial membranes and purified complex I with IC50% values of 470 μM and 340 μM respectively. Based on direct determinations of M8OI in non-mitochondrial and mitochondrial compartments, toxic M8OI concentrations were estimated to result in mitochondrial concentrations commensurate with complex I inhibition. Mitochondrial accumulation followed by complex I inhibition is therefore a possible molecular initiating event for M8OI-dependent cell death. NADH oxidation by purified complex I in combination with a flavin-site electron acceptor was not inhibited by M8OI, indicating no interaction of M8OI at the NADH-binding active site. Modelling supported M8OI binding to the ubiquinone-binding site. By inhibiting turnover, M8OI also gave rise to increases in complex-I-linked reactive oxygen species. However, inhibitors of oxidative stress did not affect M8OI-mediated cell death. The metabolic consequences of M8OI-mediated complex I inhibition, not increased reactive oxygen species production, are therefore the likely cause of apoptotic cell death. Understanding the effects on complex I and the pathways activated and leading to cell death may be informative regarding mitochondrial stress, cell death and diseases such as PBC.

Keywords:  AR42J-B13; Apoptosis; C8mim; Ionic solvents; Liver progenitor; Mitochondria

DOI:  https://doi.org/10.1016/j.chemosphere.2025.144213
bioRxiv. 2025 Feb 08. pii: 2025.02.03.636312. [Epub ahead of print]

Mitochondrial metabolism is rapidly re-activated in mature neutrophils to support stimulation-induced response.

Jorgo Lika, James A Votava, Rupsa Datta, Aleksandr M Kralovec, Frances M Smith, Anna Huttenlocher, Melissa C Skala, Jing Fan.

Neutrophils are highly abundant innate immune cells that are constantly produced from myeloid progenitors in the bone marrow. Differentiated neutrophils can perform an arsenal of effector functions critical for host defense. This study aims to quantitatively understand neutrophil mitochondrial metabolism throughout differentiation and activation, and to elucidate the impact of mitochondrial metabolism on neutrophil functions. To study metabolic remodeling throughout neutrophil differentiation, murine ER-Hoxb8 myeloid progenitor-derived neutrophils and human induced pluripotent stem cell-derived neutrophils were assessed as models. To study the metabolic remodeling upon neutrophil activation, differentiated ER-Hoxb8 neutrophils and primary human neutrophils were activated with various stimuli, including ionomycin, MSU crystals, and PMA. Characterization of cellular metabolism by isotopic tracing, extracellular flux analysis, metabolomics, and fluorescence-lifetime imaging microscopy revealed dynamic changes in mitochondrial metabolism. As neutrophils mature, mitochondrial metabolism decreases drastically, energy production is fully offloaded from oxidative phosphorylation, and glucose oxidation through TCA cycle is substantially reduced. Nonetheless, mature neutrophils retain the capacity for mitochondrial metabolism. Upon stimulation with certain stimuli, TCA cycle is rapidly activated. Mitochondrial pyruvate carrier inhibitors reduce this re-activation of the TCA cycle and inhibit the release of neutrophil extracellular traps. Mitochondrial metabolism also impacts neutrophil redox status, migration, and apoptosis without significantly changing overall bioenergetics. Together, these results demonstrate that mitochondrial metabolism is dynamically remodeled and plays a significant role in neutrophil function and fate. Furthermore, these findings point to the therapeutic potential of mitochondrial pyruvate carrier inhibitors in a range of conditions where dysregulated neutrophil response drives inflammation and contributes to pathology.

DOI: https://doi.org/10.1101/2025.02.03.636312
Cell Rep. 2025 Feb 19. pii: S2211-1247(25)00098-1. [Epub ahead of print]44(3): 115327

Targeting both the enzymatic and non-enzymatic functions of DHODH as a therapeutic vulnerability in c-Myc-driven cancer.

Qiang Zhang, Kaisa Cui, Yue Kong, Jing Yu, Zhanhao Luo, Xiaoya Yang, Liang Gong, Yanchun Xie, Jiuxiu Lin, Chen Liu, Zongjin Zhang, Yugeng Liu, Bingxin Liu, Dayi Liang, Wanyi Zeng, Zhen He, Ping Lan.

  c-Myc (Myc)-driven cancers exhibit aggressive phenotypes and therapeutic resistance. Here, integrating CRISPR-Cas9 screening, we identify dihydroorotate dehydrogenase (DHODH) as a promising target in Myc-driven cancer. Mechanistically, DHODH interacts with Myc to stabilize it independently of its enzymatic activity, thereby antagonizing SKP2-mediated polyubiquitination and proteasomal degradation. EN4, a Myc transcriptional activity inhibitor, disrupts DHODH-Myc interaction, promoting Myc degradation via SKP2. Additionally, Myc transcriptionally activates DHODH, enhancing pyrimidine biosynthesis and ferroptosis defense, processes dependent on DHODH enzymatic activity. Clinically, DHODH positively correlates with Myc, activating pyrimidine metabolism and ferroptosis defense in Myc-driven cancers. Hyperactivation of the DHODH-Myc axis is linked to colorectal cancer progression and poor prognosis. Therapeutically, combining EN4 with a DHODH enzymatic inhibitor demonstrates potent antitumor efficacy in Myc-driven colorectal cancer. Overall, our findings elucidate the metabolic and non-metabolic roles of DHODH in Myc-driven cancer, underscoring its dual potential as a therapeutic target addressing both enzymatic and non-enzymatic functions.

Keywords:  CP: Cancer; CP: Metabolism; DHODH; EN4; Myc; c-Myc-driven cancer; metabolic and non-metabolic roles; pyrimidine metabolism

DOI:  https://doi.org/10.1016/j.celrep.2025.115327
Biochem Biophys Res Commun. 2025 Feb 13. pii: S0006-291X(25)00200-1. [Epub ahead of print]753 151486

Ruxolitinib as a novel therapeutic agent targeting mitochondrial function and chemo-resistance in nasopharyngeal carcinoma.

Lin Liu, Yongbo Zhu, Yunlong Zhang.

  Chemo-resistance poses a significant obstacle in the effective treatment of nasopharyngeal carcinoma (NPC). To identify novel therapeutic strategies, we conducted high-throughput drug screening using a kinase-focused compound library on chemo-resistant NPC cells and normal human nasopharyngeal epithelial cells (HNECs). The screen identified several compounds with known anti-NPC activities, validating the robustness of the approach, and highlighted ruxolitinib, a Janus kinase (JAK) inhibitor, as a novel candidate. Ruxolitinib demonstrated selective cytotoxicity against NPC cells and exhibited strong synergy with 5-FU and cisplatin, significantly enhancing cytotoxicity in chemo-resistant cell lines. Mechanistic studies revealed that ruxolitinib disrupted mitochondrial bioenergetics through selectively inhibiting complex I activity, leading to reduced oxygen consumption rates, ATP production, and cell viability. In a chemo-resistant NPC mouse model, ruxolitinib delayed tumor growth, reduced tumor cell proliferation as indicated by decreased Ki67 staining, and extended overall survival without affecting body weight, demonstrating its efficacy and safety in vivo. These findings position ruxolitinib as a promising therapeutic agent for overcoming chemo-resistance in NPC, warranting further investigation into its clinical potential.

Keywords:  Chemoresistance; Mitochondrial function; Nasopharyngeal carcinoma; Ruxolitinib

DOI:  https://doi.org/10.1016/j.bbrc.2025.151486
Cell Signal. 2025 Feb 13. pii: S0898-6568(25)00065-8. [Epub ahead of print] 111652

STAT1 inhibition promotes oxidative stress to sustain leukemia stem cell maintenance.

Xue Han, Kexin Wang, Songqi Zhu, Weiwei Ma, Binghuo Wu, Cunte Chen, Wenjian Mo, Xiaowei Chen, Ming Zhou, Yumiao Li, Shilin Xu, Caixia Wang, Ruiqing Zhou, Peng Lei, Shunqing Wang.

  New strategy to prevent relapse and drug resistance in acute myeloid leukemia (AML) is urgently to be solved. The connection between those properties and leukemia stem cells (LSCs) in AML remains poorly understood. In this study, we demonstrate that leukemia cells with high signal transducer and activator of transcription 1 (STAT1) expression preserve quiescent properties, in contrast, leukemia cells with low STAT1 expression possess active and vulnerable apoptotic properties in AML model, highlighting the differential impact of STAT1 expression on cellular behavior in acute myeloid leukemia. STAT1 depletion damages the quiescence of LSCs and prolongs the survive of AML mice. By inhibiting STAT1 in leukemia cells, we observe a significant elevation in reactive oxygen species (ROS) levels, rendering the cells more susceptible to the detrimental effects of oxidative stress. The synergistic administration of Fludarabine, a potent STAT1 inhibitor, with conventional chemotherapy regimens, augments the efficacy of chemotherapy drugs against AML cells and the sensitivity of LSCs to chemotherapy. In a word, STAT1, as a switch, enables leukemia cells convertible in ROS high and low states. Inhibition of STAT1 enables leukemia cells more sensitive to chemotherapy, STAT1 as a new target offers a promising strategy in AML treatment.

Keywords:  Acute myeloid leukemia (AML); Leukemia stem cells (LSCs); Oxidative stress; Signal transducer and activator of transcription 1 (STAT1)

DOI:  https://doi.org/10.1016/j.cellsig.2025.111652
Nature. 2025 Feb 19.

Cooperative nutrient scavenging is an evolutionary advantage in cancer.

Gizem Guzelsoy, Setiembre D Elorza, Manon Ros, Logan T Schachtner, Makiko Hayashi, Spencer Hobson-Gutierrez, Parker Rundstrom, Julia S Brunner, Ray Pillai, William E Walkowicz, Lydia W S Finley, Maxime Deforet, Thales Papagiannakopoulos, Carlos Carmona-Fontaine.

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.

DOI: https://doi.org/10.1038/s41586-025-08588-w
Nat Commun. 2025 Feb 20. 16(1): 1792

Ketogenic diet suppresses colorectal cancer through the gut microbiome long chain fatty acid stearate.

Mina Tsenkova, Madita Brauer, Vitaly Igorevich Pozdeev, Marat Kasakin, Susheel Bhanu Busi, Maryse Schmoetten, Dean Cheung, Marianne Meyers, Fabien Rodriguez, Anthoula Gaigneaux, Eric Koncina, Cedric Gilson, Lisa Schlicker, Diran Herebian, Martine Schmitz, Laura de Nies, Ertan Mayatepek, Serge Haan, Carine de Beaufort, Thorsten Cramer, Johannes Meiser, Carole L Linster, Paul Wilmes, Elisabeth Letellier.

Colorectal cancer (CRC) patients have been shown to possess an altered gut microbiome. Diet is a well-established modulator of the microbiome, and thus, dietary interventions might have a beneficial effect on CRC. An attenuating effect of the ketogenic diet (KD) on CRC cell growth has been previously observed, however the role of the gut microbiome in driving this effect remains unknown. Here, we describe a reduced colonic tumor burden upon KD consumption in a CRC mouse model with a humanized microbiome. Importantly, we demonstrate a causal relationship through microbiome transplantation into germ-free mice, whereby alterations in the gut microbiota were maintained in the absence of continued selective pressure from the KD. Specifically, we identify a shift toward bacterial species that produce stearic acid in ketogenic conditions, whereas consumers were depleted, resulting in elevated levels of free stearate in the gut lumen. This microbial product demonstrates tumor-suppressing properties by inducing apoptosis in cancer cells and decreasing colonic Th17 immune cell populations. Taken together, the beneficial effects of the KD are mediated through alterations in the gut microbiome, including, among others, increased stearic acid production, which in turn significantly reduces intestinal tumor growth.

DOI: https://doi.org/10.1038/s41467-025-56678-0
Life Sci. 2025 Feb 19. pii: S0024-3205(25)00119-5. [Epub ahead of print]366-367 123486

Heightened sensitivity to adverse effects of metformin in mtDNA mutant patient cells.

Sanna Ryytty, Katriina Nurminen, Petri Mäkinen, Anu Suomalainen, Riikka H Hämäläinen.

   AIMS: Metformin (Met) is a widely used, cost-effective, and relatively safe drug, primarily prescribed for diabetes, that also exhibits beneficial effects in other conditions, such as in cardiovascular diseases, neurological disorders, and cancer. Despite its common use, the safety of Met in patients with primary mitochondrial disease remains uncertain, as both Met and mitochondrial dysfunction increase the risk of lactic acidosis. Here we have examined the effects of Met in patient cells with m.3243A>G mitochondrial DNA mutation.
MATERIALS AND METHODS: We utilized induced pluripotent stem cells (iPSCs) derived from two m.3243A>G patients, alongside cardiomyocytes differentiated from these iPSCs (iPSC-CMs). The cells were exposed to 10, 100, and 1000 μM Met for 24 h, and the effects on cellular metabolism and mitochondrial function were evaluated.
KEY FINDINGS: While low concentrations, relative to common therapeutic plasma levels, increased mitochondrial respiration, higher concentrations decreased respiration in both patient and control cells. Furthermore, cells with high level of the m.3243A>G mutation were more sensitive to Met than control cells. Additionally, we observed a clear patient-specific response to Met in cardiomyocytes.
SIGNIFICANCE: The findings emphasize the critical importance of selecting appropriate Met concentrations in cellular experiments and demonstrate the variability in Met's effects between individuals. Moreover, the results highlight the need for caution when considering Met use in patients with primary mitochondrial disorders.

Keywords:  Cardiomyocytes; Induced pluripotent stem cells; Metformin; Mitochondrial disease; m.3243A>G

DOI:  https://doi.org/10.1016/j.lfs.2025.123486
Cancer Discov. 2025 Feb 17. OF1-OF15

High Glucose Contribution to the TCA Cycle Is a Feature of Aggressive Non-Small Cell Lung Cancer in Patients.

Ling Cai, Nia G Hammond, Alpaslan Tasdogan, Massar Alsamraae, Chendong Yang, Robert B Cameron, Peiran Quan, Ashley Solmonson, Wen Gu, Panayotis Pachnis, Mayher Kaur, Brianna K Chang, Qin Zhou, Christopher T Hensley, Quyen N Do, Luiza Martins Nascentes Melo, Jessalyn M Ubellacker, Akash Kaushik, Maia G Clare, Isabel N Alcazar, Katarzyna Kurylowicz, Joseph D Marcuccilli, Gabriele Allies, Andrea Kutritz, Joachim Klode, Vijayashree Ramesh, Thomas J Rogers, Aparna D Rao, Hannah E Crentsil, Hong Li, Fang Brister, Phyllis McDaniel, Xiaohong Xu, Bret M Evers, Lauren G Zacharias, Jessica Sudderth, Jian Xu, Thomas P Mathews, Dwight Oliver, John D Minna, John Waters, Sean J Morrison, Kemp H Kernstine, Brandon Faubert, Ralph J DeBerardinis.

SIGNIFICANCE: Intraoperative 13C-glucose infusions in patients with NSCLC show that tumors with high labeling of TCA cycle intermediates progress rapidly, resulting in metastasis and early death. Blocking this pathway suppresses metastasis of human NSCLC cells in mice.

DOI: https://doi.org/10.1158/2159-8290.CD-23-1319
J Med Chem. 2025 Feb 20.

ONC201-Derived Tetrahydropyridopyrimidindiones as Powerful ClpP Protease Activators to Tackle Diffuse Midline Glioma.

Morena Miciaccia, Olga Maria Baldelli, Cosimo G Fortuna, Gianfranco Cavallaro, Domenico Armenise, Anselma Liturri, Savina Ferorelli, Denise P Muñoz, Alessandro Bonifazi, Francesca Rizzo, Antonella Cormio, Silvana Filieri, Giuseppe Micalizzi, Paola Dugo, Luigi Mondello, Anna Maria Sardanelli, Francesco Bruni, Paola Loguercio Polosa, Maria Grazia Perrone, Antonio Scilimati.

Pediatric diffuse intrinsic pontine glioma (DIPG), classified under diffuse midline glioma, is a deadly tumor, with no effective treatments. The human mitochondrial protease hClpP is a potential DIPG therapeutic target, and this study describes the synthesis of two new series of tetrahydropyridopyrimidindiones (THPPDs) as hClpP activators. Among the tested compounds, we have identified 36 (THX6) that shows a strong hClpP activation (EC50 = 1.18 μM) and good cytotoxicity in ONC201-resistant cells (IC50 = 0.13 μM). Studying the oxidation mechanisms on cell membranes, the treatment of DIPG cells with 36 (THX6) causes a change in levels of fatty acids (PUFAs, MUFAs, and SFAs) compared to untreated cells and dysregulates the level of proteins involved in oxidative phosphorylation, biogenesis, and mitophagy that lead to a global collapse of mitochondrial integrity and function suggesting this as the mechanism through which 36 (THX6) accomplishes its antitumor activity in DIPG cell lines.

DOI: https://doi.org/10.1021/acs.jmedchem.4c01723
Nat Cell Biol. 2025 Feb 21.

Intratumour oxidative hotspots provide a niche for cancer cell dissemination.

Yoshifumi Ueda, Shigeki Kiyonaka, Laura M Selfors, Keisuke Inoue, Hiroshi Harada, Tomohiro Doura, Kunishige Onuma, Makoto Uchiyama, Ryuhei Kurogi, Yuji Yamada, Jiacheng H Sun, Reiko Sakaguchi, Yuki Tado, Haruki Omatsu, Harufumi Suzuki, Mike Aoun, Takahiro Nakayama, Taketoshi Kajimoto, Tetsuya Yano, Rikard Holmdahl, Itaru Hamachi, Masahiro Inoue, Yasuo Mori, Nobuaki Takahashi.

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.

DOI: https://doi.org/10.1038/s41556-025-01617-w