bims-mibica 2023-03-05 papers

bims-mibica

Biomed News

on Mitochondrial bioenergetics in cancer

Issue of 2023‒03‒05
29 papers selected by
Kelsey Fisher-Wellman
East Carolina University

MYC-driven increases in mitochondrial DNA copy number occur early and persist throughout prostatic cancer progression.
mcPGK1-dependent mitochondrial import of PGK1 promotes metabolic reprogramming and self-renewal of liver TICs.
Mitochondrial elongation factor 4 modulates energy metabolism and promotes breast cancer metastasis by orchestration of mitochondrial translation.
Site IQ in mitochondrial complex I generates S1QEL-sensitive superoxide/hydrogen peroxide in both the reverse and forward reactions.
Mitochondrial pyruvate metabolism regulates the activation of quiescent adult neural stem cells.
Pyruvate dehydrogenase fuels a critical citrate pool that is essential for Th17 cell effector functions.
The multifaceted mitochondrial OXA insertase.
Comprehensive Metabolic Tracing Reveals the Origin and Catabolism of Cysteine in Mammalian Tissues and Tumors.
NADK-mediated de novo NADP(H) synthesis is a metabolic adaptation essential for breast cancer metastasis.
Mitochondria-localized cGAS suppresses ferroptosis to promote cancer progression.
NRF2 activation induces NADH-reductive stress, providing a metabolic vulnerability in lung cancer.
ANKLE1 cleaves mitochondrial DNA and contributes to cancer risk by promoting apoptosis resistance and metabolic dysregulation.
Transgenic NADH dehydrogenase restores oxygen regulation of breathing in mitochondrial complex I-deficient mice.
A dual-salt fluorescent probe for specific recognition of mitochondrial NADH and potential cancer diagnosis.
Defective COX1 expression in aging mice liver.
MRPS36 provides a structural link in the eukaryotic 2-oxoglutarate dehydrogenase complex.
Ubiquinone deficiency drives reverse electron transport to disrupt hepatic metabolic homeostasis in obesity.
Mitochondrial gene expression signature predicts prognosis of pediatric acute myeloid leukemia patients.
(R)-2-hydroxyglutarate inhibits KDM5 histone lysine demethylases to drive transformation in IDH-mutant cancers.
Docosahexaenoic Acid Potentiates the Anticancer Effect of the Menadione/Ascorbate Redox Couple by Increasing Mitochondrial Superoxide and Accelerating ATP Depletion.
Combination of a New Oral Demethylating Agent, OR2100, and Venetoclax for Treatment of Acute Myeloid Leukemia.
Accumulation of branched-chain amino acids reprograms glucose metabolism in CD8+ T cells with enhanced effector function and anti-tumor response.
Dietary restriction of cysteine and methionine sensitizes gliomas to ferroptosis and induces alterations in energetic metabolism.
What is cancer metabolism?
On the cutting edge: perspectives in bioenergetics.
Tuning the Cellular Uptake and Retention of Rhodamine Dyes by Molecular Engineering for High-Contrast Imaging of Cancer Cells.
Fatty acids prime the lung as a site for tumour spread.
TOMM34 serves as a candidate therapeutic target associated with immune cell infiltration in colon cancer.
Armeniaspirol analogues disrupt the electrical potential (ΔΨ) of the proton motive force.

bioRxiv. 2023 Feb 21. pii: 2023.02.20.529259. [Epub ahead of print]

MYC-driven increases in mitochondrial DNA copy number occur early and persist throughout prostatic cancer progression.

Jiayu Chen, Qizhi Zheng, Jessica L Hicks, Levent Trabzonlu, Busra Ozbek, Tracy Jones, Ajay Vaghasia, Tatianna C Larman, Rulin Wang, Mark C Markowski, Sam R Denmeade, Kenneth J Pienta, Ralph H Hruban, Emmanuel S Antonaraskis, Anuj Gupta, Chi V Dang, Srinivasan Yegnasubramanian, Angelo M De Marzo.

Increased mitochondrial function may render some cancers vulnerable to mitochondrial inhibitors. Since mitochondrial function is regulated partly by mitochondrial DNA copy number (mtDNAcn), accurate measurements of mtDNAcn could help reveal which cancers are driven by increased mitochondrial function and may be candidates for mitochondrial inhibition. However, prior studies have employed bulk macrodissections that fail to account for cell type-specific or tumor cell heterogeneity in mtDNAcn. These studies have often produced unclear results, particularly in prostate cancer. Herein, we developed a multiplex in situ method to spatially quantify cell type specific mtDNAcn. We show that mtDNAcn is increased in luminal cells of high-grade prostatic intraepithelial neoplasia (HGPIN), is increased in prostatic adenocarcinomas (PCa), and is further elevated in metastatic castration-resistant prostate cancer. Increased PCa mtDNAcn was validated by two orthogonal methods and is accompanied by increases in mtRNAs and enzymatic activity. Mechanistically, MYC inhibition in prostate cancer cells decreases mtDNA replication and expression of several mtDNA replication genes, and MYC activation in the mouse prostate leads to increased mtDNA levels in the neoplastic prostate cells. Our in situ approach also revealed elevated mtDNAcn in precancerous lesions of the pancreas and colon/rectum, demonstrating generalization across cancer types using clinical tissue samples.

DOI: https://doi.org/10.1101/2023.02.20.529259
Nat Commun. 2023 Feb 27. 14(1): 1121

mcPGK1-dependent mitochondrial import of PGK1 promotes metabolic reprogramming and self-renewal of liver TICs.

Zhenzhen Chen, Qiankun He, Tiankun Lu, Jiayi Wu, Gaoli Shi, Luyun He, Hong Zong, Benyu Liu, Pingping Zhu.

Liver tumour-initiating cells (TICs) contribute to tumour initiation, metastasis, progression and drug resistance. Metabolic reprogramming is a cancer hallmark and plays vital roles in liver tumorigenesis. However, the role of metabolic reprogramming in TICs remains poorly explored. Here, we identify a mitochondria-encoded circular RNA, termed mcPGK1 (mitochondrial circRNA for translocating phosphoglycerate kinase 1), which is highly expressed in liver TICs. mcPGK1 knockdown impairs liver TIC self-renewal, whereas its overexpression drives liver TIC self-renewal. Mechanistically, mcPGK1 regulates metabolic reprogramming by inhibiting mitochondrial oxidative phosphorylation (OXPHOS) and promoting glycolysis. This alters the intracellular levels of α-ketoglutarate and lactate, which are modulators in Wnt/β-catenin activation and liver TIC self-renewal. In addition, mcPGK1 promotes PGK1 mitochondrial import via TOM40 interactions, reprogramming metabolism from oxidative phosphorylation to glycolysis through PGK1-PDK1-PDH axis. Our work suggests that mitochondria-encoded circRNAs represent an additional regulatory layer controlling mitochondrial function, metabolic reprogramming and liver TIC self-renewal.

DOI: https://doi.org/10.1038/s41467-023-36651-5
Arch Biochem Biophys. 2023 Feb 28. pii: S0003-9861(23)00055-3. [Epub ahead of print]737 109556

Mitochondrial elongation factor 4 modulates energy metabolism and promotes breast cancer metastasis by orchestration of mitochondrial translation.

Qianqian Chen, Min Xiao, Fei Dai, Ye Zhang, Jiayun Li, Yanwu Huo, Zhen Huang, Yi Fang, Taotao Wei.

  To cope with the requirements of energy and building blocks for rapid proliferation, cancer cells reprogram their metabolic pathways profoundly, especially in oxygen- and nutrients-deficient tumor microenvironments. However, functional mitochondria and mitochondria-dependent oxidative phosphorylation are still necessary for the tumorigenesis and metastasis of cancer cells. We show here that mitochondrial elongation factor 4 (mtEF4) is commonly upregulated in breast tumors compared to adjacent non-cancerous tissues, and is relevant to tumor progression and poor prognosis. Down regulation of mtEF4 in breast cancer cells impairs the assembly of mitochondrial respiration complexes, decreases mitochondrial respiration, reduces ATP production, attenuates the formation of lamellipodia, and suppresses cell motility in vitro and cancer metastasis in vivo. On the contrary, upregulation of mtEF4 elevates the mitochondrial oxidative phosphorylation, which contributes to the migratory capacities of breast cancer cells. mtEF4 also increases the potential of glycolysis, probably via an AMPK-related mechanism. In summary, we provide direct evidences that the aberrantly upregulated mtEF4 contributes to the metastasis of breast cancer by coordinating metabolic pathways.

Keywords:  Breast cancer; Glycolysis; Metastasis; Mitochondrial elongation factor 4; Oxidative phosphorylation; Tumorigenesis

DOI:  https://doi.org/10.1016/j.abb.2023.109556
Biochem J. 2022 Mar 02. pii: BCJ20220611. [Epub ahead of print]

Site IQ in mitochondrial complex I generates S1QEL-sensitive superoxide/hydrogen peroxide in both the reverse and forward reactions.

Edwin T Gibbs Ii, Chad A Lerner, Mark A Watson, Hoi-Shan Wong, Akos A Gerencser, Martin D Brand.

  Superoxide/hydrogen peroxide production by site IQ in complex I of the electron transport chain is conventionally assayed during reverse electron transport from ubiquinol to NAD. However, S1QELs (specific suppressors of superoxide/hydrogen peroxide production by site IQ) have potent effects in cells and in vivo during presumed forward electron transport. Therefore, we tested whether site IQ generates S1QEL-sensitive superoxide/hydrogen peroxide during forward electron transport (site IQf), or alternatively, whether reverse electron transport and associated S1QEL-sensitive superoxide/hydrogen peroxide production (site IQr) occurs in cells under normal conditions. We introduce an assay to determine if electron flow through complex I is thermodynamically forward or reverse: on blocking electron flow through complex I, the endogenous matrix NAD pool will become more reduced if flow before the challenge was forward, but more oxidised if flow was reverse. Using this assay we show in the model system of isolated rat skeletal muscle mitochondria that superoxide/hydrogen peroxide production by site IQ can be equally great whether reverse electron transport or forward electron transport is running. We show that sites IQr and IQf are equally sensitive to S1QELs, and to rotenone and piericidin A, inhibitors that block the Q-site of complex I. We exclude the possibility that some sub-fraction of the mitochondrial population running site IQr during forward electron transport is responsible for S1QEL-sensitive superoxide/hydrogen peroxide production by site IQ. Finally, we show that superoxide/hydrogen peroxide production by site IQ in cells occurs during forward electron transport, and is S1QEL-sensitive.

Keywords:  Reverse electron transport; S1QEL; complex I; electron transport chain; mitochondria; reactive oxygen species

DOI:  https://doi.org/10.1042/BCJ20220611
Sci Adv. 2023 Mar;9(9): eadd5220

Mitochondrial pyruvate metabolism regulates the activation of quiescent adult neural stem cells.

Francesco Petrelli, Valentina Scandella, Sylvie Montessuit, Nicola Zamboni, Jean-Claude Martinou, Marlen Knobloch.

Cellular metabolism is important for adult neural stem/progenitor cell (NSPC) behavior. However, its role in the transition from quiescence to proliferation is not fully understood. We here show that the mitochondrial pyruvate carrier (MPC) plays a crucial and unexpected part in this process. MPC transports pyruvate into mitochondria, linking cytosolic glycolysis to mitochondrial tricarboxylic acid cycle and oxidative phosphorylation. Despite its metabolic key function, the role of MPC in NSPCs has not been addressed. We show that quiescent NSPCs have an active mitochondrial metabolism and express high levels of MPC. Pharmacological MPC inhibition increases aspartate and triggers NSPC activation. Furthermore, genetic Mpc1 ablation in vitro and in vivo also activates NSPCs, which differentiate into mature neurons, leading to overall increased hippocampal neurogenesis in adult and aged mice. These findings highlight the importance of metabolism for NSPC regulation and identify an important pathway through which mitochondrial pyruvate import controls NSPC quiescence and activation.

DOI: https://doi.org/10.1126/sciadv.add5220
Cell Rep. 2023 Feb 26. pii: S2211-1247(23)00164-X. [Epub ahead of print]42(3): 112153

Pyruvate dehydrogenase fuels a critical citrate pool that is essential for Th17 cell effector functions.

Leticia Soriano-Baguet, Melanie Grusdat, Henry Kurniawan, Mohaned Benzarti, Carole Binsfeld, Anouk Ewen, Joseph Longworth, Lynn Bonetti, Luana Guerra, Davide G Franchina, Takumi Kobayashi, Veronika Horkova, Charlène Verschueren, Sergio Helgueta, Deborah Gérard, Tushar H More, Antonia Henne, Catherine Dostert, Sophie Farinelle, Antoine Lesur, Jean-Jacques Gérardy, Christian Jäger, Michel Mittelbronn, Lasse Sinkkonen, Karsten Hiller, Johannes Meiser, Dirk Brenner.

  Pyruvate dehydrogenase (PDH) is the central enzyme connecting glycolysis and the tricarboxylic acid (TCA) cycle. The importance of PDH function in T helper 17 (Th17) cells still remains to be studied. Here, we show that PDH is essential for the generation of a glucose-derived citrate pool needed for Th17 cell proliferation, survival, and effector function. In vivo, mice harboring a T cell-specific deletion of PDH are less susceptible to developing experimental autoimmune encephalomyelitis. Mechanistically, the absence of PDH in Th17 cells increases glutaminolysis, glycolysis, and lipid uptake in a mammalian target of rapamycin (mTOR)-dependent manner. However, cellular citrate remains critically low in mutant Th17 cells, which interferes with oxidative phosphorylation (OXPHOS), lipid synthesis, and histone acetylation, crucial for transcription of Th17 signature genes. Increasing cellular citrate in PDH-deficient Th17 cells restores their metabolism and function, identifying a metabolic feedback loop within the central carbon metabolism that may offer possibilities for therapeutically targeting Th17 cell-driven autoimmunity.

Keywords:  CP: Immunology; CP: Metabolism; IL-17; T cells; Th17 cells; acetyl-CoA; citrate; epigenetics; experimental autoimmune encephalomyelitis; glucose metabolism; histone acetylation; pyruvate dehydrogenase

DOI:  https://doi.org/10.1016/j.celrep.2023.112153
Trends Cell Biol. 2023 Feb 28. pii: S0962-8924(23)00020-X. [Epub ahead of print]

The multifaceted mitochondrial OXA insertase.

Bettina Homberg, Peter Rehling, Luis Daniel Cruz-Zaragoza.

  Most mitochondrial proteins are synthesized in the cytosol and transported into mitochondria by protein translocases. Yet, mitochondria contain their own genome and gene expression system, which generates proteins that are inserted in the inner membrane by the oxidase assembly (OXA) insertase. OXA contributes to targeting proteins from both genetic origins. Recent data provides insights into how OXA cooperates with the mitochondrial ribosome during synthesis of mitochondrial-encoded proteins. A picture of OXA emerges in which it coordinates insertion of OXPHOS core subunits and their assembly into protein complexes but also participates in the biogenesis of select imported proteins. These functions position the OXA as a multifunctional protein insertase that facilitates protein transport, assembly, and stability at the inner membrane.

Keywords:  mitochondria; oxidase assembly; oxidative phosphorylation; protein translocation; ribosomes

DOI:  https://doi.org/10.1016/j.tcb.2023.02.001
Cancer Res. 2023 Mar 02. pii: CAN-22-3000. [Epub ahead of print]

Comprehensive Metabolic Tracing Reveals the Origin and Catabolism of Cysteine in Mammalian Tissues and Tumors.

Sang Jun Yoon, Joseph A Combs, Aimee Falzone, Nicolas Prieto-Farigua, Samantha Caldwell, Hayley D Ackerman, Elsa R Flores, Gina M DeNicola.

Cysteine plays critical roles in cellular biosynthesis, enzyme catalysis, and redox metabolism. The intracellular cysteine pool can be sustained by cystine uptake or de novo synthesis from serine and homocysteine. Demand for cysteine is increased during tumorigenesis for generating glutathione to deal with oxidative stress. While cultured cells have been shown to be highly dependent on exogenous cystine for proliferation and survival, how diverse tissues obtain and use cysteine in vivo has not been characterized. We comprehensively interrogated cysteine metabolism in normal murine tissues and cancers that arise from them using stable isotope 13C1-serine and 13C6-cystine tracing. De novo cysteine synthesis was highest in normal liver and pancreas and absent in lung tissue, while cysteine synthesis was either inactive or downregulated during tumorigenesis. By contrast, cystine uptake and metabolism to downstream metabolites was a universal feature of normal tissues and tumors. However, differences in glutathione labeling from cysteine were evident across tumor types. Thus, cystine is a major contributor to the cysteine pool in tumors, and glutathione metabolism is differentially active across tumor types.

DOI: https://doi.org/10.1158/0008-5472.CAN-22-3000
Redox Biol. 2023 Feb 09. pii: S2213-2317(23)00028-9. [Epub ahead of print]61 102627

NADK-mediated de novo NADP(H) synthesis is a metabolic adaptation essential for breast cancer metastasis.

Didem Ilter, Stanislav Drapela, Tanya Schild, Nathan P Ward, Emma Adhikari, Vivien Low, John Asara, Thordur Oskarsson, Eric K Lau, Gina M DeNicola, Melanie R McReynolds, Ana P Gomes.

  Metabolic reprogramming and metabolic plasticity allow cancer cells to fine-tune their metabolism and adapt to the ever-changing environments of the metastatic cascade, for which lipid metabolism and oxidative stress are of particular importance. NADPH is a central co-factor for both lipid and redox homeostasis, suggesting that cancer cells may require larger pools of NADPH to efficiently metastasize. NADPH is recycled through reduction of NADP+ by several enzymatic systems in cells; however, de novo NADP+ is synthesized only through one known enzymatic reaction, catalyzed by NAD+ kinase (NADK). Here, we show that NADK is upregulated in metastatic breast cancer cells enabling de novo production of NADP(H) and the expansion of the NADP(H) pools thereby increasing the ability of these cells to adapt to the challenges of the metastatic cascade and efficiently metastasize. Mechanistically, we found that metastatic signals lead to a histone H3.3 variant-mediated epigenetic regulation of the NADK promoter, resulting in increased NADK levels in cells with metastatic ability. Together, our work presents a previously uncharacterized role for NADK and de novo NADP(H) production as a contributor to breast cancer progression and suggests that NADK constitutes an important and much needed therapeutic target for metastatic breast cancers.

Keywords:  Breast cancer; Metastasis; NADK; NADPH; Redox

DOI:  https://doi.org/10.1016/j.redox.2023.102627
Cell Res. 2023 Mar 02.

Mitochondria-localized cGAS suppresses ferroptosis to promote cancer progression.

Shiqiao Qiu, Xiuying Zhong, Xiang Meng, Shiting Li, Xiaoyu Qian, Hui Lu, Jin Cai, Yi Zhang, Mingjie Wang, Zijian Ye, Huafeng Zhang, Ping Gao.

A well-established role of cyclic GMP-AMP synthase (cGAS) is the recognition of cytosolic DNA, which is linked to the activation of host defense programs against pathogens via stimulator of interferon genes (STING)-dependent innate immune response. Recent advance has also revealed that cGAS may be involved in several noninfectious contexts by localizing to subcellular compartments other than the cytosol. However, the subcellular localization and function of cGAS in different biological conditions is unclear; in particular, its role in cancer progression remains poorly understood. Here we show that cGAS is localized to mitochondria and protects hepatocellular carcinoma cells from ferroptosis in vitro and in vivo. cGAS anchors to the outer mitochondrial membrane where it associates with dynamin-related protein 1 (DRP1) to facilitate its oligomerization. In the absence of cGAS or DRP1 oligomerization, mitochondrial ROS accumulation and ferroptosis increase, inhibiting tumor growth. Collectively, this previously unrecognized role for cGAS in orchestrating mitochondrial function and cancer progression suggests that cGAS interactions in mitochondria can serve as potential targets for new cancer interventions.

DOI: https://doi.org/10.1038/s41422-023-00788-1
Cell Metab. 2023 Feb 22. pii: S1550-4131(23)00012-8. [Epub ahead of print]

NRF2 activation induces NADH-reductive stress, providing a metabolic vulnerability in lung cancer.

Tommy Weiss-Sadan, Maolin Ge, Makiko Hayashi, Magdy Gohar, Cong-Hui Yao, Adriaan de Groot, Stefan Harry, Alexander Carlin, Hannah Fischer, Lei Shi, Ting-Yu Wei, Charles H Adelmann, Konstantin Wolf, Tristan Vornbäumen, Benedikt R Dürr, Mariko Takahashi, Marianne Richter, Junbing Zhang, Tzu-Yi Yang, Vindhya Vijay, David E Fisher, Aaron N Hata, Marcia C Haigis, Raul Mostoslavsky, Nabeel Bardeesy, Thales Papagiannakopoulos, Liron Bar-Peled.

  Multiple cancers regulate oxidative stress by activating the transcription factor NRF2 through mutation of its negative regulator, KEAP1. NRF2 has been studied extensively in KEAP1-mutant cancers; however, the role of this pathway in cancers with wild-type KEAP1 remains poorly understood. To answer this question, we induced NRF2 via pharmacological inactivation of KEAP1 in a panel of 50+ non-small cell lung cancer cell lines. Unexpectedly, marked decreases in viability were observed in >13% of the cell lines-an effect that was rescued by NRF2 ablation. Genome-wide and targeted CRISPR screens revealed that NRF2 induces NADH-reductive stress, through the upregulation of the NAD+-consuming enzyme ALDH3A1. Leveraging these findings, we show that cells treated with KEAP1 inhibitors or those with endogenous KEAP1 mutations are selectively vulnerable to Complex I inhibition, which impairs NADH oxidation capacity and potentiates reductive stress. Thus, we identify reductive stress as a metabolic vulnerability in NRF2-activated lung cancers.

Keywords:  NADH/NAD(+); NRF2-KEAP1 pathway; functional genomic; non-small cell lung cancer; oxidative phosphorylation; reductive stress

DOI:  https://doi.org/10.1016/j.cmet.2023.01.012
Commun Biol. 2023 Mar 01. 6(1): 231

ANKLE1 cleaves mitochondrial DNA and contributes to cancer risk by promoting apoptosis resistance and metabolic dysregulation.

Piotr Przanowski, Róża K Przanowska, Michael J Guertin.

Alleles within the chr19p13.1 locus are associated with increased risk of both ovarian and breast cancer and increased expression of the ANKLE1 gene. ANKLE1 is molecularly characterized as an endonuclease that efficiently cuts branched DNA and shuttles between the nucleus and cytoplasm. However, the role of ANKLE1 in mammalian development and homeostasis remains unknown. In normal development ANKLE1 expression is limited to the erythroblast lineage and we found that ANKLE1's role is to cleave the mitochondrial genome during erythropoiesis. We show that ectopic expression of ANKLE1 in breast epithelial-derived cells leads to genome instability and mitochondrial DNA (mtDNA) cleavage. mtDNA degradation then leads to mitophagy and causes a shift from oxidative phosphorylation to glycolysis (Warburg effect). Moreover, mtDNA degradation activates STAT1 and expression of epithelial-mesenchymal transition (EMT) genes. Reduction in mitochondrial content contributes to apoptosis resistance, which may allow precancerous cells to avoid apoptotic checkpoints and proliferate. These findings provide evidence that ANKLE1 is the causal cancer susceptibility gene in the chr19p13.1 locus and describe mechanisms by which higher ANKLE1 expression promotes cancer risk.

DOI: https://doi.org/10.1038/s42003-023-04611-w
Nat Commun. 2023 Mar 01. 14(1): 1172

Transgenic NADH dehydrogenase restores oxygen regulation of breathing in mitochondrial complex I-deficient mice.

Blanca Jiménez-Gómez, Patricia Ortega-Sáenz, Lin Gao, Patricia González-Rodríguez, Paula García-Flores, Navdeep Chandel, José López-Barneo.

The hypoxic ventilatory response (HVR) is a life-saving reflex, triggered by the activation of chemoreceptor glomus cells in the carotid body (CB) connected with the brainstem respiratory center. The molecular mechanisms underlying glomus cell acute oxygen (O2) sensing are unclear. Genetic disruption of mitochondrial complex I (MCI) selectively abolishes the HVR and glomus cell responsiveness to hypoxia. However, it is unknown what functions of MCI (metabolic, proton transport, or signaling) are essential for O2 sensing. Here we show that transgenic mitochondrial expression of NDI1, a single-molecule yeast NADH/quinone oxidoreductase that does not directly contribute to proton pumping, fully recovers the HVR and glomus cell sensitivity to hypoxia in MCI-deficient mice. Therefore, maintenance of mitochondrial NADH dehydrogenase activity and the electron transport chain are absolutely necessary for O2-dependent regulation of breathing. NDI1 expression also rescues other systemic defects caused by MCI deficiency. These data explain the role of MCI in acute O2 sensing by arterial chemoreceptors and demonstrate the optimal recovery of complex organismal functions by gene therapy.

DOI: https://doi.org/10.1038/s41467-023-36894-2
Talanta. 2023 Feb 24. pii: S0039-9140(23)00144-3. [Epub ahead of print]257 124393

A dual-salt fluorescent probe for specific recognition of mitochondrial NADH and potential cancer diagnosis.

Qi Wang, Yanzhe Zhu, Debao Chen, Jiale Ou, Man Chen, Yan Feng, Wenbin Wang, Xiangming Meng.

  Reduced nicotinamide adenine dinucleotide (NADH) is a kind of coenzyme and widely works as a biomarker in cancer cells. It plays a crucial role in many cellular metabolic processes, especially NADH in mitochondria is indispensable for the mitochondrial respiration chain that produces ATP. Herein, we designed a fluorescent probe Mito-FCC based on an ethylene-bridging dual-salt structure, in which benzo[e]indolium fluorophore was used as the mitochondria-targeting group and 1-methylquinolinium moiety as the NADH recognition unit. Mito-FCC exhibited high sensitivity and selectivity for NADH with a rapid "turn-on" fluorescence signal. The dual-salt structure endowed the probe with a reliable mitochondria-targeted ability even after the recognition unit was reduced by NADH. With the help of the probe, the fluctuations of endogenous NADH induced by glucose or pyruvate were imaged. Besides, Mito-FCC had a capability to make a distinction between cancer cells and normal cells due that the content of NADH in cancer cells was distinctly higher than that in normal ones. Notably, the visualization of tumor in vivo through monitoring NADH using Mito-FCC was realized successfully. These experimental results showed that Mito-FCC hold a great perspective in study of mitochondrial function and potential diagnosis of cancer diseases.

Keywords:  Bioimaging; Cancer diagnosis; Fluorescent probe; Mitochondria; NADH

DOI:  https://doi.org/10.1016/j.talanta.2023.124393
Biol Open. 2023 Mar 15. pii: bio059844. [Epub ahead of print]12(3):

Defective COX1 expression in aging mice liver.

Steffen Witte, Angela Boshnakovska, Metin Özdemir, Arpita Chowdhury, Peter Rehling, Abhishek Aich.

  Mitochondrial defects are associated with aging processes and age-related diseases, including cardiovascular diseases, neurodegenerative diseases and cancer. In addition, some recent studies suggest mild mitochondrial dysfunctions appear to be associated with longer lifespans. In this context, liver tissue is considered to be largely resilient to aging and mitochondrial dysfunction. Yet, in recent years studies report dysregulation of mitochondrial function and nutrient sensing pathways in ageing livers. Therefore, we analyzed the effects of the aging process on mitochondrial gene expression in liver using wildtype C57BL/6N mice. In our analyses, we observed alteration in mitochondrial energy metabolism with age. To assess if defects in mitochondrial gene expression are linked to this decline, we applied a Nanopore sequencing based approach for mitochondrial transcriptomics. Our analyses show that a decrease of the Cox1 transcript correlates with reduced respiratory complex IV activity in older mice livers.

Keywords:  Ageing; Mitochondria; Nanopore; Transcriptomics

DOI:  https://doi.org/10.1242/bio.059844
Open Biol. 2023 03;13(3): 220363

MRPS36 provides a structural link in the eukaryotic 2-oxoglutarate dehydrogenase complex.

Johannes F Hevler, Pascal Albanese, Alfredo Cabrera-Orefice, Alisa Potter, Andris Jankevics, Jelena Misic, Richard A Scheltema, Ulrich Brandt, Susanne Arnold, Albert J R Heck.

  The tricarboxylic acid cycle is the central pathway of energy production in eukaryotic cells and plays a key part in aerobic respiration throughout all kingdoms of life. One of the pivotal enzymes in this cycle is 2-oxoglutarate dehydrogenase complex (OGDHC), which generates NADH by oxidative decarboxylation of 2-oxoglutarate to succinyl-CoA. OGDHC is a megadalton protein complex originally thought to be assembled from three catalytically active subunits (E1o, E2o, E3). In fungi and animals, however, the protein MRPS36 has more recently been proposed as a putative additional component. Based on extensive cross-linking mass spectrometry data supported by phylogenetic analyses, we provide evidence that MRPS36 is an important member of the eukaryotic OGDHC, with no prokaryotic orthologues. Comparative sequence analysis and computational structure predictions reveal that, in contrast with bacteria and archaea, eukaryotic E2o does not contain the peripheral subunit-binding domain (PSBD), for which we propose that MRPS36 evolved as an E3 adaptor protein, functionally replacing the PSBD. We further provide a refined structural model of the complete eukaryotic OGDHC of approximately 3.45 MDa with novel mechanistic insights.

Keywords:  2-oxoglutarate dehydrogenase (OGDHC); MRPS36; complexome profiling; cross-linking mass spectrometry; structural biology; tricarboxylic acid (TCA) cycle

DOI:  https://doi.org/10.1098/rsob.220363
bioRxiv. 2023 Feb 22. pii: 2023.02.21.528863. [Epub ahead of print]

Ubiquinone deficiency drives reverse electron transport to disrupt hepatic metabolic homeostasis in obesity.

Renata L S Goncalves, Zeqiu Branden Wang, Karen E Inouye, Grace Yankun Lee, Xiaorong Fu, Jani Saksi, Clement Rosique, Gunes Parlakgul, Ana Paula Arruda, Sheng Tony Hui, Mar Coll Loperena, Shawn C Burgess, Isabel Graupera, Gökhan S Hotamisligil.

Mitochondrial reactive oxygen species (mROS) are central to physiology. While excess mROS production has been associated with several disease states, its precise sources, regulation, and mechanism of generation in vivo remain unknown, limiting translational efforts. Here we show that in obesity, hepatic ubiquinone (Q) synthesis is impaired, which raises the QH 2 /Q ratio, driving excessive mROS production via reverse electron transport (RET) from site I Q in complex I. Using multiple complementary genetic and pharmacological models in vivo we demonstrated that RET is critical for metabolic health. In patients with steatosis, the hepatic Q biosynthetic program is also suppressed, and the QH 2 /Q ratio positively correlates with disease severity. Our data identify a highly selective mechanism for pathological mROS production in obesity, which can be targeted to protect metabolic homeostasis.

DOI: https://doi.org/10.1101/2023.02.21.528863
Front Oncol. 2023 ;13 1109518

Mitochondrial gene expression signature predicts prognosis of pediatric acute myeloid leukemia patients.

Shilpi Chaudhary, Shuvadeep Ganguly, Jayanth Kumar Palanichamy, Archna Singh, Dibyabhaba Pradhan, Radhika Bakhshi, Anita Chopra, Sameer Bakhshi.

  Introduction: Gene expression profile of mitochondrial-related genes is not well deciphered in pediatric acute myeloid leukaemia (AML). We aimed to identify mitochondria-related differentially expressed genes (DEGs) in pediatric AML with their prognostic significance.Methods: Children with de novo AML were included prospectively between July 2016-December 2019. Transcriptomic profiling was done for a subset of samples, stratified by mtDNA copy number. Top mitochondria-related DEGs were identified and validated by real-time PCR. A prognostic gene signature risk score was formulated using DEGs independently predictive of overall survival (OS) in multivariable analysis. Predictive ability of the risk score was estimated along with external validation in The Tumor Genome Atlas (TCGA) AML dataset.
Results: In 143 children with AML, twenty mitochondria-related DEGs were selected for validation, of which 16 were found to be significantly dysregulated. Upregulation of SDHC (p<0.001), CLIC1 (p=0.013) and downregulation of SLC25A29 (p<0.001) were independently predictive of inferior OS, and included for developing prognostic risk score. The risk score model was independently predictive of survival over and above ELN risk categorization (Harrell's c-index: 0.675). High-risk patients (risk score above median) had significantly inferior OS (p<0.001) and event free survival (p<0.001); they were associated with poor-risk cytogenetics (p=0.021), ELN intermediate/poor risk group (p=0.016), absence of RUNX1-RUNX1T1 (p=0.027), and not attaining remission (p=0.016). On external validation, the risk score also predicted OS (p=0.019) in TCGA dataset.
Discussion: We identified and validated mitochondria-related DEGs with prognostic impact in pediatric AML and also developed a novel 3-gene based externally validated gene signature predictive of survival.

Keywords:  RNA sequencing; acute myeloid leukema; child; gene signature; mitochondria

DOI:  https://doi.org/10.3389/fonc.2023.1109518
Cancer Discov. 2023 Feb 27. pii: CD-22-0825. [Epub ahead of print]

(R)-2-hydroxyglutarate inhibits KDM5 histone lysine demethylases to drive transformation in IDH-mutant cancers.

Kathryn Gunn, Matti Myllykoski, John Z Cao, Manna Ahmed, Bofu Huang, Betty Rouaisnel, Bill H Diplas, Michael M Levitt, Ryan Looper, John G Doench, Keith L Ligon, Harley I Kornblum, Samuel K McBrayer, Hai Yan, Cihangir Duy, Lucy A Godley, Peppi Koivunen, Julie-Aurore Losman.

Oncogenic mutations in isocitrate dehydrogenase (IDH)-1 and -2 occur in a wide range of cancers, including acute myeloid leukemia (AML) and glioma. Mutant IDH enzymes convert 2-oxoglutarate (2OG) to (R)-2-hydroxyglutarate ((R)-2HG)), an oncometabolite that is hypothesized to promote cellular transformation by dysregulating 2OG-dependent enzymes. The only (R)-2HG target that has been convincingly shown to contribute to transformation by mutant IDH is the myeloid tumor suppressor TET2. However, there is ample evidence to suggest that (R)-2HG has other functionally relevant targets in IDH-mutant cancers. Here, we show that (R)-2HG inhibits KDM5 histone lysine demethylases and that this inhibition contributes to cellular transformation in IDH-mutant AML and IDH-mutant glioma. These studies provide the first evidence of a functional link between dysregulation of histone lysine methylation and transformation in IDH-mutant cancers.

DOI: https://doi.org/10.1158/2159-8290.CD-22-0825
Anticancer Res. 2023 Mar;43(3): 1213-1220

Docosahexaenoic Acid Potentiates the Anticancer Effect of the Menadione/Ascorbate Redox Couple by Increasing Mitochondrial Superoxide and Accelerating ATP Depletion.

Donika Ivanova, Severina Semkova, Zvezdelina Yaneva, Biliana Nikolova, Zhivko Zhelev, Rumiana Bakalova, Ichio Aoki.

  BACKGROUND/AIM: Mitochondria-targeted anticancer drugs ("mitocans") of natural origin are attractive candidates as adjuvants in cancer therapy. The redox couple menadione/ascorbate (M/A), which belongs to the "mitocans" family, induces selective oxidative stress in cancerous mitochondria and cells, respectively. DHA has also been found to regulate the mevalonate pathway, which is closely related to the prenylation of the cytotoxic menadione to the non-cytotoxic menaquinone. The aim of this study was to elucidate the ability of docosahexaenoic acid (DHA) to potentiate the anticancer effect of M/A by increasing ROS production, as well as affecting steady-state ATP levels in cancer cells.MATERIALS AND METHODS: The experiments were performed on leukemic lymphocyte Jurkat. Cells were treated with DHA, M/A, and their combination (M/A/DHA) and four parameters were examined using the following assays: cell viability and proliferation, steady-state ATP, mitochondrial superoxide, intracellular hydroperoxides. Three independent experiments with two or six parallel measurements were performed for each parameter.
RESULTS: The triple combination M/A/DHA was characterized by much higher antiproliferative activity and cytotoxicity than M/A and DHA administered alone. DHA significantly accelerated M/A-induced ATP depletion in cells, which was accompanied by an additional increase in mitochondrial superoxide compared to cells treated with M/A or DHA alone.
CONCLUSION: DHA significantly enhanced M/A-induced cytotoxicity in leukemic lymphocytes by inducing severe mitochondrial oxidative stress and accelerated ATP depletion. Selective DHA-mediated suppression of cholesterol synthesis in cancer cells (involved in the prenylation of cytotoxic menadione to the less cytotoxic phylloquinone), as well as DHA-mediated inhibition of superoxide dismutase are suggested to underlie the potentiation of the anticancer effect of M/A.

Keywords:  ATP; Docosahexaenoic acid; leukemia; menadione/ascorbate; mitochondrial superoxide

DOI:  https://doi.org/10.21873/anticanres.16268
Cancer Res Commun. 2023 Feb;3(2): 297-308

Combination of a New Oral Demethylating Agent, OR2100, and Venetoclax for Treatment of Acute Myeloid Leukemia.

Kazuharu Kamachi, Hiroshi Ureshino, Tatsuro Watanabe, Nao Yoshida-Sakai, Yuki Fukuda-Kurahashi, Kazunori Kawasoe, Toshimi Hoshiko, Yuta Yamamoto, Yuki Kurahashi, Shinya Kimura.

The standard treatment for elderly patients with acute myeloid leukemia (AML) is venetoclax (Ven), a BCL-2-selective inhibitor, combined with hypomethylating agents (HMA) such as azacitidine or decitabine. This regimen results in low toxicity, high response rates, and potentially durable remission; however, because of low oral bioavailability, these conventional HMAs must be administered intravenously or subcutaneously. A combination of oral HMAs and Ven would provide a therapeutic advantage over parenteral administration of drugs and improve quality of life by reducing the number of hospital visits. Previously, we showed the promising oral bioavailability and antileukemia effects of a new HMA, OR2100 (OR21). Here, we investigated the efficacy and underlying mechanism of OR21 when used in combination with Ven to treat AML. OR21/Ven showed synergistic antileukemia effects in vitro, and significantly prolonged survival without increasing toxicity in a human leukemia xenograft mice model. RNA sequencing following combination therapy revealed downregulation of VAMP7, which is involved in autophagic maintenance of mitochondrial homeostasis. Combination therapy led to accumulation of reactive oxygen species, leading to increased apoptosis. The data suggest that the combination of OR21 plus Ven is a promising candidate oral therapy for AML.Significance: The standard treatment for elderly patients with AML is Ven combined with HMAs. OR21, a new oral HMA plus Ven showed synergistic antileukemia effects in vitro and vivo, suggesting that the combination of OR2100 plus Ven is a promising candidate oral therapy for AML.

DOI: https://doi.org/10.1158/2767-9764.CRC-22-0259
Cell Rep. 2023 Mar 03. pii: S2211-1247(23)00197-3. [Epub ahead of print]42(3): 112186

Accumulation of branched-chain amino acids reprograms glucose metabolism in CD8+ T cells with enhanced effector function and anti-tumor response.

Cheng-Cheng Yao, Rui-Ming Sun, Yi Yang, Hai-Yan Zhou, Zhou-Wenli Meng, Rui Chi, Li-Liang Xia, Ping Ji, Ying-Ying Chen, Guo-Qing Zhang, Hai-Peng Sun, Shun Lu, Chen Yang, Ying Wang.

  Branched-chain amino acids (BCAAs) provide nutrient signals for cell survival and growth. How BCAAs affect CD8+ T cell functions remains unexplored. Herein, we report that accumulation of BCAAs in CD8+ T cells due to the impairment of BCAA degradation in 2C-type serine/threonine protein phosphatase (PP2Cm)-deficient mice leads to hyper-activity of CD8+ T cells and enhanced anti-tumor immunity. CD8+ T cells from PP2Cm-/- mice upregulate glucose transporter Glut1 expression in a FoxO1-dependent manner with more glucose uptake, as well as increased glycolysis and oxidative phosphorylation. Moreover, BCAA supplementation recapitulates CD8+ T cell hyper-functions and synergizes with anti-PD-1, in line with a better prognosis in NSCLC patients containing high BCAAs when receiving anti-PD-1 therapy. Our finding thus reveals that accumulation of BCAAs promotes effector function and anti-tumor immunity of CD8+ T cells through reprogramming glucose metabolism, making BCAAs alternative supplementary components to increase the clinical efficacy of anti-PD-1 immunotherapy against tumors.

Keywords:  CD8(+) T cells; CP: Immunology; anti-tumor immunity; branched-chain amino acid accumulation; effector function; glucose metabolism; synergy with anti-PD-1 treatment

DOI:  https://doi.org/10.1016/j.celrep.2023.112186
Nat Commun. 2023 Mar 02. 14(1): 1187

Dietary restriction of cysteine and methionine sensitizes gliomas to ferroptosis and induces alterations in energetic metabolism.

Pavan S Upadhyayula, Dominique M Higgins, Angeliki Mela, Matei Banu, Athanassios Dovas, Fereshteh Zandkarimi, Purvi Patel, Aayushi Mahajan, Nelson Humala, Trang T T Nguyen, Kunal R Chaudhary, Lillian Liao, Michael Argenziano, Tejaswi Sudhakar, Colin P Sperring, Benjamin L Shapiro, Eman R Ahmed, Connor Kinslow, Ling F Ye, Markus D Siegelin, Simon Cheng, Rajesh Soni, Jeffrey N Bruce, Brent R Stockwell, Peter Canoll.

Ferroptosis is mediated by lipid peroxidation of phospholipids containing polyunsaturated fatty acyl moieties. Glutathione, the key cellular antioxidant capable of inhibiting lipid peroxidation via the activity of the enzyme glutathione peroxidase 4 (GPX-4), is generated directly from the sulfur-containing amino acid cysteine, and indirectly from methionine via the transsulfuration pathway. Herein we show that cysteine and methionine deprivation (CMD) can synergize with the GPX4 inhibitor RSL3 to increase ferroptotic cell death and lipid peroxidation in both murine and human glioma cell lines and in ex vivo organotypic slice cultures. We also show that a cysteine-depleted, methionine-restricted diet can improve therapeutic response to RSL3 and prolong survival in a syngeneic orthotopic murine glioma model. Finally, this CMD diet leads to profound in vivo metabolomic, proteomic and lipidomic alterations, highlighting the potential for improving the efficacy of ferroptotic therapies in glioma treatment with a non-invasive dietary modification.

DOI: https://doi.org/10.1038/s41467-023-36630-w
Cell. 2023 Feb 22. pii: S0092-8674(23)00097-1. [Epub ahead of print]

What is cancer metabolism?

Lydia W S Finley.

The uptake and metabolism of nutrients support fundamental cellular process from bioenergetics to biomass production and cell fate regulation. While many studies of cell metabolism focus on cancer cells, the principles of metabolism elucidated in cancer cells apply to a wide range of mammalian cells. The goal of this review is to discuss how the field of cancer metabolism provides a framework for revealing principles of cell metabolism and for dissecting the metabolic networks that allow cells to meet their specific demands. Understanding context-specific metabolic preferences and liabilities will unlock new approaches to target cancer cells to improve patient care.

DOI: https://doi.org/10.1016/j.cell.2023.01.038
Nat Rev Endocrinol. 2023 Mar 03.

On the cutting edge: perspectives in bioenergetics.

Melia Granath-Panelo, Anna Krook, Jared Rutter, Shingo Kajimura.

DOI: https://doi.org/10.1038/s41574-023-00820-9
Angew Chem Int Ed Engl. 2023 Feb 28. e202218613

Tuning the Cellular Uptake and Retention of Rhodamine Dyes by Molecular Engineering for High-Contrast Imaging of Cancer Cells.

Gangwei Jiang, Xiao-Feng Lou, Shan Zuo, Xixuan Liu, Tian-Bing Ren, Lu Wang, Xiao-Bing Zhang, Lin Yuan.

  Probes allowing high-contrast discrimination of cancer cells and effective retention are powerful tools for the early diagnosis and treatment of cancer. However, conventional small-molecule probes often show limited performance in both aspects. Herein, we report an ingenious molecular engineering strategy for tuning the cellular uptake and retention of rhodamine dyes. Introduction of polar aminoethyl lead to the increased brightness and reduced cellular uptake of dyes, and this change can be reversed by amino acetylation. Moreover, these modifications allow cancer cells to take up more dyes than normal cells (16-fold) through active transport. Specifically, we further improve the signal contrast (56-fold) between cancer and normal cells by constructing activatable probes and confirm that the released fluorophore can remain in cancer cells with extended time, enabling long-term and specific tumor imaging.

Keywords:  Fluorescent probe; activatable molecular probe; cancer cells; cellular uptake; molecular imaging

DOI:  https://doi.org/10.1002/anie.202218613
Nature. 2023 Feb 28.

Fatty acids prime the lung as a site for tumour spread.

Laura V Pinheiro, Kathryn E Wellen.



Keywords:  Cancer; Medical research; Metabolism

DOI:  https://doi.org/10.1038/d41586-023-00538-8
Front Oncol. 2023 ;13 947364

TOMM34 serves as a candidate therapeutic target associated with immune cell infiltration in colon cancer.

Zhigui Li, Hongzhao Yang, Jianbo Liu, Li Li, Xiaodong Wang.

  Background: Colon cancer represents one of the most pervasive digestive malignancies worldwide. Translocase of the outer mitochondrial membrane 34 (TOMM34) is considered an oncogene and is implicated in tumor proliferation. However, the correlation between TOMM34 and immune cell infiltration in colon cancer has not been investigated.Materials and methods: Based on multiple open online databases, we performed integrated bioinformatics analysis of TOMM34 to evaluate the prognostic value of TOMM34 and its correlation with immune cell infiltration.
Results: TOMM34 gene and protein expression levels were elevated in tumor tissues compared with normal tissues. Survival analysis revealed that upregulation of TOMM34 was significantly associated with poorer survival time in colon cancer. High TOMM34 expression was dramatically related to low levels of B cells, CD8+ T cells, neutrophils, dendritic cells, PD-1, PD-L1 and CTLA-4.
Conclusions: Our results confirmed that high expression of TOMM34 in tumor tissue correlates with immune cell infiltration and worse prognosis in colon cancer patients. TOMM34 may serve as a potential prognostic biomarker for colon cancer diagnosis and prognosis prediction.

Keywords:  Tomm34; colon cancer; immune infiltration; immunotherapy; prognostic biomarker

DOI:  https://doi.org/10.3389/fonc.2023.947364
Bioorg Med Chem Lett. 2023 Feb 27. pii: S0960-894X(23)00088-4. [Epub ahead of print] 129210

Armeniaspirol analogues disrupt the electrical potential (ΔΨ) of the proton motive force.

Michael G Darnowski, Taylor D Lanosky, André R Paquette, Christopher N Boddy.

The armeniaspirol family of natural products antibiotics have been shown to inhibit the ATP-dependent proteases ClpXP and ClpYQ and disrupt membrane potential through shuttling of protons across the membrane. Herein we investigate their ability to disrupt the proton motive force (PMF). We show, using a voltage sensitive, that armeniaspiols disrupt the electrical membrane potential (ΔΨ) component of the PMF and not the transmembrane proton gradient (ΔpH). Using checkerboard assays, we confirm this by showing antagonism, with kanamycin, an antibiotic that required ΔΨ for penetration. By evaluating the antibiotic activity and disruption of the PMF by fourteen armeniaspirol analogs, we find that disruption of the PMF is necessary but not sufficient for antibiotic activity. Analogs that are potent disruptors of the PMF without possessing the ability to inhibit ClpXP and ClpYQ are not potent antibiotics. Thus we propose that the armeniaspirols utilize a dual mechanism of action where they disrupt PMF and inhibit the ATP-dependent proteases ClpXP and ClpYQ. This type of dual mechanism has been observed in other natural product-based antibiotics, most notably chelocardin.

DOI: https://doi.org/10.1016/j.bmcl.2023.129210