bims-medica 2023-11-19 papers

bims-medica

Biomed News

on Metabolism and diet in cancer

Issue of 2023–11–19
25 papers selected by
Brett Chrest, East Carolina University

The Warburg Effect Explained: Integration of Enhanced Glycolysis with Heterogeneous Mitochondria to Promote Cancer Cell Proliferation.
Succinate as a signaling molecule in the mediation of liver diseases.
AML under the Scope: Current Strategies and Treatment Involving FLT3 Inhibitors and Venetoclax-Based Regimens.
Mitochondrial adaptation decreases drug sensitivity of persistent triple negative breast cancer cells surviving combinatory and sequential chemotherapy.
Changes in Plasma Pyruvate and TCA Cycle Metabolites upon Increased Hepatic Fatty Acid Oxidation and Ketogenesis in Male Wistar Rats.
Cholesterol Metabolism in Pancreatic Cancer.
Rewiring of cortical glucose metabolism fuels human brain cancer growth.
Avoiding Extinction: Cancer-Associated Fibroblasts Help Triple-Negative Breast Cancer Outrun Chemotherapy.
Ferroptosis induction via targeting metabolic alterations in triple-negative breast cancer.
The mechanisms of action of mitochondrial targeting agents in cancer: inhibiting oxidative phosphorylation and inducing apoptosis.
Perspectives and challenges of small molecule inhibitor therapy for FLT3-mutated acute myeloid leukemia.
A novel CPT1A covalent inhibitor modulates fatty acid oxidation and CPT1A-VDAC1 axis with therapeutic potential for colorectal cancer.
Inhibition of the proline metabolism rate-limiting enzyme P5CS allows proliferation of glutamine-restricted cancer cells.
Cristae dynamics is modulated in bioenergetically compromised mitochondria.
Ketone body β-hydroxybutyrate (BHB) preserves mitochondrial bioenergetics.
The enzymes of the oxidative phase of the pentose phosphate pathway as targets of reactive species: consequences for NADPH production.
Fatty acids abrogate the growth-suppressive effects induced by inhibition of cholesterol flux in pancreatic cancer cells.
NAD+ regulates nucleotide metabolism and genomic DNA replication.
One-carbon unit supplementation fuels tumor-infiltrating T cells and augments checkpoint blockade.
p53-responsive CMBL reprograms glucose metabolism and suppresses cancer development by destabilizing phosphofructokinase PFKP.
The mitochondrial regulation in ferroptosis signaling pathway and its potential strategies for cancer.
Lineage Plasticity: the New Cancer Hallmark on the Block.
Quantification of cell death and proliferation of patient-derived ovarian cancer organoids through 3D imaging and image analysis.
Identification of a selective FLT3 inhibitor with low activity against VEGFR, FGFR, PDGFR, c-KIT, and RET anti-targets.
Establishment and Comprehensive Molecular Characterization of an Immortalized Glioblastoma Cell Line from a Brazilian Patient.

Int J Mol Sci. 2023 Oct 31. pii: 15787. [Epub ahead of print]24(21):

The Warburg Effect Explained: Integration of Enhanced Glycolysis with Heterogeneous Mitochondria to Promote Cancer Cell Proliferation.

Lilia Alberghina.

  The Warburg effect is the long-standing riddle of cancer biology. How does aerobic glycolysis, inefficient in producing ATP, confer a growth advantage to cancer cells? A new evaluation of a large set of literature findings covering the Warburg effect and its yeast counterpart, the Crabtree effect, led to an innovative working hypothesis presented here. It holds that enhanced glycolysis partially inactivates oxidative phosphorylation to induce functional rewiring of a set of TCA cycle enzymes to generate new non-canonical metabolic pathways that sustain faster growth rates. The hypothesis has been structured by constructing two metabolic maps, one for cancer metabolism and the other for the yeast Crabtree effect. New lines of investigation, suggested by these maps, are discussed as instrumental in leading toward a better understanding of cancer biology in order to allow the development of more efficient metabolism-targeted anticancer drugs.

Keywords:  ATP synthase; OXPHOS; ROS; cancer; cellular biochemistry; mitochondria

DOI:  https://doi.org/10.3390/ijms242115787
Biochim Biophys Acta Mol Basis Dis. 2023 Nov 15. pii: S0925-4439(23)00301-0. [Epub ahead of print]1870(2): 166935

Succinate as a signaling molecule in the mediation of liver diseases.

Hui Chen, Cheng Jin, Li Xie, Jian Wu.

  Succinate, one of the intermediates of the tricarboxylic acid (TCA) cycle, plays an essential role in the metabolism of mitochondria and the production of energy, and is considered as a signaling molecule in metabolism as well as in initiation and progression of hepatic diseases. Of note, succinate activates a downstream signaling pathway through GPR91, and elicits a variety of intracellular responses, such as succinylation, production of reactive oxygen species (ROS), stabilization of hypoxia-inducible factor-1α (HIF-1α), and significant impact in cellular metabolism because of the pivotal role in the TCA cycle. Therefore, it is intriguing to deeply elucidate signaling mechanisms of succinate in hepatic fibrosis, metabolic reprogramming in inflammatory or immune responses, as well as carcinogenesis. This manuscript intends to review current understanding of succinate in mediating metabolism, inflammatory and immunologic reactions in liver diseases in order to establish molecular basis for the development of therapeutic strategies.

Keywords:  HIF-1α stabilization; Hepatic fibrosis; Liver cancer; Metabolic reprogramming; Microenvironment; Succinate

DOI:  https://doi.org/10.1016/j.bbadis.2023.166935
Int J Mol Sci. 2023 Oct 31. pii: 15849. [Epub ahead of print]24(21):

AML under the Scope: Current Strategies and Treatment Involving FLT3 Inhibitors and Venetoclax-Based Regimens.

Szymon Milnerowicz, Julia Maszewska, Paulina Skowera, Magdalena Stelmach, Monika Lejman.

  Acute myeloid leukemia (AML) is a disease that mainly affects elderly patients who are more often unfit for intensive chemotherapy (median age of diagnosis is 68). The regimens, including venetoclax, a highly specific BCL-2 (B-cell lymphoma-2) inhibitor, are a common alternative because of their safer profile and fewer side effects. However, the resistance phenomenon of leukemic cells necessitates the search for drugs that would help to overcome the resistance and improve treatment outcomes. One of the resistance mechanisms takes place through the upregulation of MCL-1 and BCL-XL, preventing BAX/BAK-driven MOMP (mitochondrial outer membrane permeabilization), thus stopping the apoptosis process. Possible partners for BCL-2 inhibitors may include inhibitors from the FLT3i (FMS-like tyrosine kinase-3 inhibitor) group. They resensitize cancer cells through the downregulation of MCL-1 expression in the FLT3 mutated cells, resulting in the stronger efficacy of BCL-2 inhibitors. Also, they provide an additional pathway for targeting the clonal cell. Both preclinical and clinical data suggest that the combination might show a synergistic effect and improve patients' outcomes. The aim of this review is to determine whether the combination of venetoclax and FLT3 inhibitors can impact the therapeutic approaches and what other agents they can be combined with.

Keywords:  BCL-2 (B-cell lymphoma-2) inhibitors; FLT3 (FMS-like tyrosine kinase-3) inhibitors; FLT3-internal tandem duplication (ITD); acute myeloid leukemia (AML); tyrosine kinase inhibitors (TKI)

DOI:  https://doi.org/10.3390/ijms242115849
Neoplasia. 2023 Nov 11. pii: S1476-5586(23)00073-8. [Epub ahead of print]46 100949

Mitochondrial adaptation decreases drug sensitivity of persistent triple negative breast cancer cells surviving combinatory and sequential chemotherapy.

Marie Winter, Amina Nait Eldjoudi, Catherine Guette, Hubert Hondermarck, Roland P Bourette, Quentin Fovez, William Laine, Bart Ghesquiere, Eric Adriaenssens, Jérôme Kluza, Xuefen Le Bourhis.

  Triple negative breast cancer (TNBC) is an aggressive malignancy for which chemotherapy remains the standard treatment. However, between 3 and 5 years after chemotherapy, about half patients will relapse and it is essential to identify vulnerabilities of cancer cells surviving neoadujuvant therapy. In this study, we established persistent TNBC cell models after treating MDA-MB-231 and SUM159-PT TNBC cell lines with epirubicin and cyclophosphamide, and then with paclitaxel, for a total of 18 weeks. The resulting chemo-persistent cell lines were more proliferative, both in vitro and in xenografted mice. Interestingly, MDA-MB-231 persistent cells became less sensitive to chemotherapeutic drugs, whereas SUM159-PT persistent cells kept similar sensitivity compared to control cells. The reduced sensitivity to chemotherapy in MDA-MB-231 persistent cells was found to be associated with an increased oxidative phosphorylation (OXPHOS) and modified levels of tricarboxylic acid cycle (TCA) intermediates. Integration of data from proteomics and metabolomics demonstrated TCA cycle among the most upregulated pathways in MDA-MB-231 persistent cells. The absence of glucose and pyruvate impeded OXPHOS in persistent cells, while the absence of glutamine did not. In contrast, OXPHOS was not modified in control cells independently of TCA substrates, indicating that MDA-MB-231 persistent cells evolved towards a more pyruvate dependent profile. Finally, the inhibition of pyruvate entry into mitochondria with UK-5099 reduced OXPHOS and re-sensitized persistent cells to therapeutic agents. Together, these findings suggest that targeting mitochondrial pyruvate metabolism may help to overcome mitochondrial adaptation of chemo-persistent TNBC.

Keywords:  Chemotherapy; Mitochondrial adaptation; Persistence; Pyruvate; Resistance

DOI:  https://doi.org/10.1016/j.neo.2023.100949
Int J Mol Sci. 2023 Oct 24. pii: 15536. [Epub ahead of print]24(21):

Changes in Plasma Pyruvate and TCA Cycle Metabolites upon Increased Hepatic Fatty Acid Oxidation and Ketogenesis in Male Wistar Rats.

Simon Nitter Dankel, Tine-Lise Kalleklev, Siri Lunde Tungland, Marit Hallvardsdotter Stafsnes, Per Bruheim, Thomas Aquinas Aloysius, Carine Lindquist, Jon Skorve, Ottar Kjell Nygård, Lise Madsen, Bodil Bjørndal, Magne Olav Sydnes, Rolf Kristian Berge.

  Altered hepatic mitochondrial fatty acid β-oxidation and associated tricarboxylic acid (TCA) cycle activity contributes to lifestyle-related diseases, and circulating biomarkers reflecting these changes could have disease prognostic value. This study aimed to determine hepatic and systemic changes in TCA-cycle-related metabolites upon the selective pharmacologic enhancement of mitochondrial fatty acid β-oxidation in the liver, and to elucidate the mechanisms and potential markers of hepatic mitochondrial activity. Male Wistar rats were treated with 3-thia fatty acids (e.g., tetradecylthioacetic acid (TTA)), which target mitochondrial biogenesis, mitochondrial fatty acid β-oxidation, and ketogenesis predominantly in the liver. Hepatic and plasma concentrations of TCA cycle intermediates and anaplerotic substrates (LC-MS/MS), plasma ketones (colorimetric assay), and acylcarnitines (HPLC-MS/MS), along with associated TCA-cycle-related gene expression (qPCR) and enzyme activities, were determined. TTA-induced hepatic fatty acid β-oxidation resulted in an increased ratio of plasma ketone bodies/nonesterified fatty acid (NEFA), lower plasma malonyl-CoA levels, and a higher ratio of plasma acetylcarnitine/palmitoylcarnitine (C2/C16). These changes were associated with decreased hepatic and increased plasma pyruvate concentrations, and increased plasma concentrations of succinate, malate, and 2-hydroxyglutarate. Expression of several genes encoding TCA cycle enzymes and the malate-oxoglutarate carrier (Slc25a11), glutamate dehydrogenase (Gdh), and malic enzyme (Mdh1 and Mdh2) were significantly increased. In conclusion, the induction of hepatic mitochondrial fatty acid β-oxidation by 3-thia fatty acids lowered hepatic pyruvate while increasing plasma pyruvate, as well as succinate, malate, and 2-hydroxyglutarate.

Keywords:  biomarkers; fatty acid oxidation; ketogenesis; liver; mitochondria

DOI:  https://doi.org/10.3390/ijms242115536
Cancers (Basel). 2023 Oct 27. pii: 5177. [Epub ahead of print]15(21):

Cholesterol Metabolism in Pancreatic Cancer.

Artur Rebelo, Jörg Kleeff, Yoshiaki Sunami.

  Pancreatic cancer's substantial impact on cancer-related mortality, responsible for 8% of cancer deaths and ranking fourth in the US, persists despite advancements, with a five-year relative survival rate of only 11%. Forecasts predict a 70% surge in new cases and a 72% increase in global pancreatic cancer-related deaths by 2040. This review explores the intrinsic metabolic reprogramming of pancreatic cancer, focusing on the mevalonate pathway, including cholesterol biosynthesis, transportation, targeting strategies, and clinical studies. The mevalonate pathway, central to cellular metabolism, significantly shapes pancreatic cancer progression. Acetyl coenzyme A (Acetyl-CoA) serves a dual role in fatty acid and cholesterol biosynthesis, fueling acinar-to-ductal metaplasia (ADM) and pancreatic intraepithelial neoplasia (PanIN) development. Enzymes, including acetoacetyl-CoA thiolase, 3-hydroxy-3methylglutaryl-CoA (HMG-CoA) synthase, and HMG-CoA reductase, are key enzymes in pancreatic cancer. Inhibiting HMG-CoA reductase, e.g., by using statins, shows promise in delaying PanIN progression and impeding pancreatic cancer. Dysregulation of cholesterol modification, uptake, and transport significantly impacts tumor progression, with Sterol O-acyltransferase 1 (SOAT1) driving cholesterol ester (CE) accumulation and disrupted low-density lipoprotein receptor (LDLR) expression contributing to cancer recurrence. Apolipoprotein E (ApoE) expression in tumor stroma influences immune suppression. Clinical trials targeting cholesterol metabolism, including statins and SOAT1 inhibitors, exhibit potential anti-tumor effects, and combination therapies enhance efficacy. This review provides insights into cholesterol metabolism's convergence with pancreatic cancer, shedding light on therapeutic avenues and ongoing clinical investigations.

Keywords:  cholesterol metabolism; clinical trial; lipid metabolism; lipoprotein; mevalonate pathway; pancreatic cancer

DOI:  https://doi.org/10.3390/cancers15215177
medRxiv. 2023 Oct 25. pii: 2023.10.24.23297489. [Epub ahead of print]

Rewiring of cortical glucose metabolism fuels human brain cancer growth.

Andrew J Scott, Anjali Mittal, Baharan Meghdadi, Sravya Palavalasa, Abhinav Achreja, Alexandra O'Brien, Ayesha U Kothari, Weihua Zhou, Jie Xu, Angelica Lin, Kari Wilder-Romans, Donna M Edwards, Zhe Wu, Jiane Feng, Anthony C Andren, Li Zhang, Vijay Tarnal, Kimberly A Redic, Nathan Qi, Joshua Fischer, Ethan Yang, Michael S Regan, Sylwia A Stopka, Gerard Baquer, Theodore S Lawrence, Sriram Venneti, Nathalie Y R Agar, Costas A Lyssiotis, Wajd N Al-Holou, Deepak Nagrath, Daniel R Wahl.

The brain avidly consumes glucose to fuel neurophysiology. Cancers of the brain, such as glioblastoma (GBM), lose aspects of normal biology and gain the ability to proliferate and invade healthy tissue. How brain cancers rewire glucose utilization to fuel these processes is poorly understood. Here we perform infusions of 13 C-labeled glucose into patients and mice with brain cancer to define the metabolic fates of glucose-derived carbon in tumor and cortex. By combining these measurements with quantitative metabolic flux analysis, we find that human cortex funnels glucose-derived carbons towards physiologic processes including TCA cycle oxidation and neurotransmitter synthesis. In contrast, brain cancers downregulate these physiologic processes, scavenge alternative carbon sources from the environment, and instead use glucose-derived carbons to produce molecules needed for proliferation and invasion. Targeting this metabolic rewiring in mice through dietary modulation selectively alters GBM metabolism and slows tumor growth.
Significance: This study is the first to directly measure biosynthetic flux in both glioma and cortical tissue in human brain cancer patients. Brain tumors rewire glucose carbon utilization away from oxidation and neurotransmitter production towards biosynthesis to fuel growth. Blocking these metabolic adaptations with dietary interventions slows brain cancer growth with minimal effects on cortical metabolism.

DOI: https://doi.org/10.1101/2023.10.24.23297489
Cancer Res. 2023 Nov 15. 83(22): 3667-3669

Avoiding Extinction: Cancer-Associated Fibroblasts Help Triple-Negative Breast Cancer Outrun Chemotherapy.

Steven W Wall, Gloria V Echeverria.

Neoadjuvant chemotherapy is a staple of triple-negative breast cancer (TNBC) treatment. Predicated on the principle of fractional cell killing, chemotherapy regimens are typically cycles of short drug exposure followed by a period of recovery from the toxic side effects. However, many patients experience chemotherapy resistance for a variety of reasons, resulting in tumors that are not sufficiently reduced with treatment. Response to chemotherapy prior to surgical resection is a strong predictor of patient prognosis; therefore, finding ways to improve efficacy is a critical need. Tremendous effort has gone into understanding the relationship between the tumor microenvironment and treatment sensitivity in many tumor types. In this issue of Cancer Research, Miroshnychenko and colleagues investigate how the well-characterized phenomenon of cancer-associated fibroblast (CAF)-induced proliferation of tumor cells allows TNBC to evade extinction after multiple cycles of cytotoxic chemotherapies. Their findings imply CAF-promoted tumor cell proliferation allows tumor cells to push through stressful conditions caused by treatment and to avoid tumor elimination. This mechanism of 'indirect' chemoresistance contrasts with the dogma that tumor cell proliferation enhances chemosensitivity. This study opens the door for the discovery of mechanisms and therapeutic targets to limit the ability of CAFs to rescue tumor cells from the brink of extinction. See related article by Miroshnychenko et al., p. 3681.

DOI: https://doi.org/10.1158/0008-5472.CAN-23-2770
Biomed Pharmacother. 2023 Nov 09. pii: S0753-3322(23)01664-5. [Epub ahead of print]169 115866

Ferroptosis induction via targeting metabolic alterations in triple-negative breast cancer.

Yaru Wang, Yue Sun, Feiran Wang, Hongyi Wang, Jing Hu.

  Triple-negative breast cancer (TNBC), the most aggressive form of breast cancer, presents severe threats to women's health. Therefore, it is critical to find novel treatment approaches. Ferroptosis, a newly identified form of programmed cell death, is marked by the buildup of lipid reactive oxygen species (ROS) and high iron concentrations. According to previous studies, ferroptosis sensitivity can be controlled by a number of metabolic events in cells, such as amino acid metabolism, iron metabolism, and lipid metabolism. Given that TNBC tumors are rich in iron and lipids, inducing ferroptosis in these tumors is a potential approach for TNBC treatment. Notably, the metabolic adaptability of cancer cells allows them to coordinate an attack on one or more metabolic pathways to initiate ferroptosis, offering a novel perspective to improve the high drug resistance and clinical therapy of TNBC. However, a clear picture of ferroptosis in TNBC still needs to be completely revealed. In this review, we provide an overview of recent advancements regarding the connection between ferroptosis and amino acid, iron, and lipid metabolism in TNBC. We also discuss the probable significance of ferroptosis as an innovative target for chemotherapy, radiotherapy, immunotherapy, nanotherapy and natural product therapy in TNBC, highlighting its therapeutic potential and application prospects.

Keywords:  Ferroptosis; Metabolic reprogramming; Therapy; Triple-negative breast cancer (TNBC)

DOI:  https://doi.org/10.1016/j.biopha.2023.115866
Front Pharmacol. 2023 ;14 1243613

The mechanisms of action of mitochondrial targeting agents in cancer: inhibiting oxidative phosphorylation and inducing apoptosis.

Yi Yang, Yahui An, Mingli Ren, Haijiao Wang, Jing Bai, Wenli Du, Dezhi Kong.

  The tumor microenvironment affects the structure and metabolic function of mitochondria in tumor cells. This process involves changes in metabolic activity, an increase in the amount of reactive oxygen species (ROS) in tumor cells compared to normal cells, the production of more intracellular free radicals, and the activation of oxidative pathways. From a practical perspective, it is advantageous to develop drugs that target mitochondria for the treatment of malignant tumors. Such drugs can enhance the selectivity of treatments for specific cell groups, minimize toxic effects on normal tissues, and improve combinational treatments. Mitochondrial targeting agents typically rely on small molecule medications (such as synthetic small molecules agents, active ingredients of plants, mitochondrial inhibitors or autophagy inhibitors, and others), modified mitochondrial delivery system agents (such as lipophilic cation modification or combining other molecules to form targeted mitochondrial agents), and a few mitochondrial complex inhibitors. This article will review these compounds in three main areas: oxidative phosphorylation (OXPHOS), changes in ROS levels, and endogenous oxidative and apoptotic processes.

Keywords:  electron transport chain (ETC); mechanism; mitocans; mitochondria targeting drug; oxidative phoshorylation; reactive oxygen species

DOI:  https://doi.org/10.3389/fphar.2023.1243613
Ann Hematol. 2023 Nov 17.

Perspectives and challenges of small molecule inhibitor therapy for FLT3-mutated acute myeloid leukemia.

Coen J Lap, Marwa Sh Abrahim, Samah Nassereddine.

  Acute myeloid leukemia (AML) is a heterogeneous clonal disease characterized overall by an aggressive clinical course. The underlying genetic abnormalities present in leukemic cells contribute significantly to the AML phenotype. Mutations in FMS-like tyrosine kinase 3 (FLT3) are one of the most common genetic abnormalities identified in AML, and the presence of these mutations strongly influences disease presentation and negatively impacts prognosis. Since mutations in FLT3 were identified in AML, they have been recognized as a valid therapeutic target resulting in decades of research to develop effective small molecule inhibitor treatment that could improve outcome for these patients. Despite the approval of several FLT3 inhibitors over the last couple of years, the treatment of patients with FLT3-mutated AML remains challenging and many questions still need to be addressed. This review will provide an up-to-date overview of our current understanding of FLT3-mutated AML and discuss what the current status is of the available FLT3 inhibitors for the day-to-day management of this aggressive disease.

Keywords:  AML; FLT3; Gilteritinib; Midostaurin; Precision medicine; Quizartinib; Treatment

DOI:  https://doi.org/10.1007/s00277-023-05545-3
Redox Biol. 2023 Nov 10. pii: S2213-2317(23)00360-9. [Epub ahead of print]68 102959

A novel CPT1A covalent inhibitor modulates fatty acid oxidation and CPT1A-VDAC1 axis with therapeutic potential for colorectal cancer.

Anni Hu, Hang Wang, Qianqian Xu, Yuqi Pan, Zeyu Jiang, Sheng Li, Yi Qu, Yili Hu, Hao Wu, Xinzhi Wang.

  Colorectal cancer (CRC) is a common and deadly disease of the digestive system, but its targeted therapy is hampered by the lack of reliable and specific biomarkers. Hence, discovering new therapeutic targets and agents for CRC is an urgent and challenging task. Here we report that carnitine palmitoyltransferase 1A (CPT1A), a mitochondrial enzyme that catalyzes fatty acid oxidation (FAO), is a potential target for CRC treatment. We show that CPT1A is overexpressed in CRC cells and that its inhibition by a secolignan-type compound, 2,6-dihydroxypeperomin B (DHP-B), isolated from the plant Peperomia dindygulensis, suppresses tumor cell growth and induces apoptosis. We demonstrate that DHP-B covalently binds to Cys96 of CPT1A, blocks FAO, and disrupts the mitochondrial CPT1A-VDAC1 interaction, leading to increased mitochondrial permeability and reduced oxygen consumption and energy metabolism in CRC cells. We also reveal that CPT1A expression correlates with the survival of tumor-bearing animals and that DHP-B exhibits anti-CRC activity in vitro and in vivo. Our study uncovers the molecular mechanism of DHP-B as a novel CPT1A inhibitor and provides a rationale for its preclinical development as well as a new strategy for CRC targeted therapy.

Keywords:  2,6-Dihydroxypeperomin B; CPT1A; Colorectal cancer; Covalent inhibitor; VDAC1

DOI:  https://doi.org/10.1016/j.redox.2023.102959
Nat Metab. 2023 Nov 13.

Inhibition of the proline metabolism rate-limiting enzyme P5CS allows proliferation of glutamine-restricted cancer cells.

Samantha J Linder, Tiziano Bernasocchi, Bárbara Martínez-Pastor, Kelly D Sullivan, Matthew D Galbraith, Caroline A Lewis, Christina M Ferrer, Ruben Boon, Giorgia G Silveira, Hyo Min Cho, Charles Vidoudez, Stuti Shroff, Joao P Oliveira-Costa, Kenneth N Ross, Rami Massri, Yusuke Matoba, Eugene Kim, Bo R Rueda, Shannon L Stott, Eyal Gottlieb, Joaquin M Espinosa, Raul Mostoslavsky.

Glutamine is a critical metabolite for rapidly proliferating cells as it is used for the synthesis of key metabolites necessary for cell growth and proliferation. Glutamine metabolism has been proposed as a therapeutic target in cancer and several chemical inhibitors are in development or in clinical trials. How cells subsist when glutamine is limiting is poorly understood. Here, using an unbiased screen, we identify ALDH18A1, which encodes P5CS, the rate-limiting enzyme in the proline biosynthetic pathway, as a gene that cells can downregulate in response to glutamine starvation. Notably, P5CS downregulation promotes de novo glutamine synthesis, highlighting a previously unrecognized metabolic plasticity of cancer cells. The glutamate conserved from reducing proline synthesis allows cells to produce the key metabolites necessary for cell survival and proliferation under glutamine-restricted conditions. Our findings reveal an adaptive pathway that cancer cells acquire under nutrient stress, identifying proline biosynthesis as a previously unrecognized major consumer of glutamate, a pathway that could be exploited for developing effective metabolism-driven anticancer therapies.

DOI: https://doi.org/10.1038/s42255-023-00919-3
Life Sci Alliance. 2024 Feb;pii: e202302386. [Epub ahead of print]7(2):

Cristae dynamics is modulated in bioenergetically compromised mitochondria.

Mathias Golombek, Thanos Tsigaras, Yulia Schaumkessel, Sebastian Hänsch, Stefanie Weidtkamp-Peters, Ruchika Anand, Andreas S Reichert, Arun Kumar Kondadi.

Cristae membranes have been recently shown to undergo intramitochondrial merging and splitting events. Yet, the metabolic and bioenergetic factors regulating them are unclear. Here, we investigated whether and how cristae morphology and dynamics are dependent on oxidative phosphorylation (OXPHOS) complexes, the mitochondrial membrane potential (ΔΨm), and the ADP/ATP nucleotide translocator. Advanced live-cell STED nanoscopy combined with in-depth quantification were employed to analyse cristae morphology and dynamics after treatment of mammalian cells with rotenone, antimycin A, oligomycin A, and CCCP. This led to formation of enlarged mitochondria along with reduced cristae density but did not impair cristae dynamics. CCCP treatment leading to ΔΨm abrogation even enhanced cristae dynamics showing its ΔΨm-independent nature. Inhibition of OXPHOS complexes was accompanied by reduced ATP levels but did not affect cristae dynamics. However, inhibition of ADP/ATP exchange led to aberrant cristae morphology and impaired cristae dynamics in a mitochondrial subset. In sum, we provide quantitative data of cristae membrane remodelling under different conditions supporting an important interplay between OXPHOS, metabolite exchange, and cristae membrane dynamics.

DOI: https://doi.org/10.26508/lsa.202302386
Sci Rep. 2023 11 11. 13(1): 19664

Ketone body β-hydroxybutyrate (BHB) preserves mitochondrial bioenergetics.

I Llorente-Folch, H Düssmann, O Watters, N M C Connolly, Jochen H M Prehn.

The ketogenic diet is an emerging therapeutic approach for refractory epilepsy, as well as certain rare and neurodegenerative disorders. The main ketone body, β-hydroxybutyrate (BHB), is the primary energy substrate endogenously produced in a ketogenic diet, however, mechanisms of its therapeutic actions remain unknown. Here, we studied the effects of BHB on mitochondrial energetics, both in non-stimulated conditions and during glutamate-mediated hyperexcitation. We found that glutamate-induced hyperexcitation stimulated mitochondrial respiration in cultured cortical neurons, and that this response was greater in cultures supplemented with BHB than with glucose. BHB enabled a stronger and more sustained maximal uncoupled respiration, indicating that BHB enables neurons to respond more efficiently to increased energy demands such as induced during hyperexcitation. We found that cytosolic Ca2+ was required for BHB-mediated enhancement of mitochondrial function, and that this enhancement was independent of the mitochondrial glutamate-aspartate carrier, Aralar/AGC1. Our results suggest that BHB exerts its protective effects against hyperexcitation by enhancing mitochondrial function through a Ca2+-dependent, but Aralar/AGC1-independent stimulation of mitochondrial respiration.

DOI: https://doi.org/10.1038/s41598-023-46776-8
Biochem Soc Trans. 2023 Nov 16. pii: BST20231027. [Epub ahead of print]

The enzymes of the oxidative phase of the pentose phosphate pathway as targets of reactive species: consequences for NADPH production.

Eduardo Fuentes-Lemus, Juan Sebastián Reyes, Juan David Figueroa, Michael J Davies, Camilo López-Alarcón.

  The pentose phosphate pathway (PPP) is a key metabolic pathway. The oxidative phase of this process involves three reactions catalyzed by glucose-6-phosphate dehydrogenase (G6PDH), 6-phosphogluconolactonase (6PGL) and 6-phosphogluconate dehydrogenase (6PGDH) enzymes. The first and third steps (catalyzed by G6PDH and 6PGDH, respectively) are responsible for generating reduced nicotinamide adenine dinucleotide phosphate (NAPDH), a key cofactor for maintaining the reducing power of cells and detoxification of both endogenous and exogenous oxidants and electrophiles. Despite the importance of these enzymes, little attention has been paid to the fact that these proteins are targets of oxidants. In response to oxidative stimuli metabolic pathways are modulated, with the PPP often up-regulated in order to enhance or maintain the reductive capacity of cells. Under such circumstances, oxidation and inactivation of the PPP enzymes could be detrimental. Damage to the PPP enzymes may result in a downward spiral, as depending on the extent and sites of modification, these alterations may result in a loss of enzymatic activity and therefore increased oxidative damage due to NADPH depletion. In recent years, it has become evident that the three enzymes of the oxidative phase of the PPP have different susceptibilities to inactivation on exposure to different oxidants. In this review, we discuss existing knowledge on the role that these enzymes play in the metabolism of cells, and their susceptibility to oxidation and inactivation with special emphasis on NADPH production. Perspectives on achieving a better understanding of the molecular basis of the oxidation these enzymes within cellular environments are given.

Keywords:  6-phosphogluconate dehydrogenase; 6-phosphogluconolactonase; NADPH; glucose-6-phosphate dehydrogenase; pentose phosphate pathway; protein oxidation

DOI:  https://doi.org/10.1042/BST20231027
Cancer Cell Int. 2023 Nov 17. 23(1): 276

Fatty acids abrogate the growth-suppressive effects induced by inhibition of cholesterol flux in pancreatic cancer cells.

Yuchuan Li, Manoj Amrutkar, Anette Vefferstad Finstadsveen, Knut Tomas Dalen, Caroline S Verbeke, Ivar P Gladhaug.

   BACKGROUND: Despite therapeutic advances, the prognosis of pancreatic ductal adenocarcinoma (PDAC) remains extremely poor. Metabolic reprogramming is increasingly recognized as a key contributor to tumor progression and therapy resistance in PDAC. One of the main metabolic changes essential for tumor growth is altered cholesterol flux. Targeting cholesterol flux appears an attractive therapeutic approach, however, the complex regulation of cholesterol balance in PDAC cells remains poorly understood.
METHODS: The lipid content in human pancreatic duct epithelial (HPDE) cells and human PDAC cell lines (BxPC-3, MIA PaCa-2, and PANC-1) was determined. Cells exposed to eight different inhibitors targeting different regulators of lipid flux, in the presence or absence of oleic acid (OA) stimulation were assessed for changes in viability, proliferation, migration, and invasion. Intracellular content and distribution of cholesterol was assessed. Lastly, proteome profiling of PANC-1 exposed to the sterol O-acyltransferase 1 (SOAT1) inhibitor avasimibe, in presence or absence of OA, was performed.
RESULTS: PDAC cells contain more free cholesterol but less cholesteryl esters and lipid droplets than HPDE cells. Exposure to different lipid flux inhibitors increased cell death and suppressed proliferation, with different efficiency in the tested PDAC cell lines. Avasimibe had the strongest ability to suppress proliferation across the three PDAC cell lines. All inhibitors showing cell suppressive effect disturbed intracellular cholesterol flux and increased cholesterol aggregation. OA improved overall cholesterol balance, reduced free cholesterol aggregation, and reversed cell death induced by the inhibitors. Treatment with avasimibe changed the cellular proteome substantially, mainly for proteins related to biosynthesis and metabolism of lipids and fatty acids, apoptosis, and cell adhesion. Most of these changes were restored by OA.
CONCLUSIONS: The study reveals that disturbing the cholesterol flux by inhibiting the actions of its key regulators can yield growth suppressive effects on PDAC cells. The presence of fatty acids restores intracellular cholesterol balance and abrogates the alternations induced by cholesterol flux inhibitors. Taken together, targeting cholesterol flux might be an attractive strategy to develop new therapeutics against PDAC. However, the impact of fatty acids in the tumor microenvironment must be taken into consideration.

Keywords:  Cholesterol; Fatty acids; Lipid flux; Pancreatic cancer

DOI:  https://doi.org/10.1186/s12935-023-03138-8
Nat Cell Biol. 2023 Nov 13.

NAD+ regulates nucleotide metabolism and genomic DNA replication.

Sebastian Howen Nesgaard Munk, Joanna Maria Merchut-Maya, Alba Adelantado Rubio, Arnaldur Hall, George Pappas, Giacomo Milletti, MyungHee Lee, Lea Giørtz Johnsen, Per Guldberg, Jiri Bartek, Apolinar Maya-Mendoza.

The intricate orchestration of enzymatic activities involving nicotinamide adenine dinucleotide (NAD+) is essential for maintaining metabolic homeostasis and preserving genomic integrity. As a co-enzyme, NAD+ plays a key role in regulating metabolic pathways, such as glycolysis and Kreb's cycle. ADP-ribosyltransferases (PARPs) and sirtuins rely on NAD+ to mediate post-translational modifications of target proteins. The activation of PARP1 in response to DNA breaks leads to rapid depletion of cellular NAD+ compromising cell viability. Therefore, the levels of NAD+ must be tightly regulated. Here we show that exogenous NAD+, but not its precursors, has a direct effect on mitochondrial activity. Short-term incubation with NAD+ boosts Kreb's cycle and the electron transport chain and enhances pyrimidine biosynthesis. Extended incubation with NAD+ results in depletion of pyrimidines, accumulation of purines, activation of the replication stress response and cell cycle arrest. Moreover, a combination of NAD+ and 5-fluorouridine selectively kills cancer cells that rely on de novo pyrimidine synthesis. We propose an integrated model of how NAD+ regulates nucleotide metabolism, with relevance to healthspan, ageing and cancer therapy.

DOI: https://doi.org/10.1038/s41556-023-01280-z
bioRxiv. 2023 Nov 03. pii: 2023.11.01.565193. [Epub ahead of print]

One-carbon unit supplementation fuels tumor-infiltrating T cells and augments checkpoint blockade.

Xincheng Xu, Zihong Chen, Caroline R Bartman, Xi Xing, Kellen Olszewski, Joshua D Rabinowitz.

Nucleotides perform important metabolic functions, carrying energy and feeding nucleic acid synthesis. Here, we use isotope tracing-mass spectrometry to quantitate the contributions to purine nucleotides of salvage versus de novo synthesis. We further explore the impact of augmenting a key precursor for purine synthesis, one-carbon (1C) units. We show that tumors and tumor-infiltrating T cells (relative to splenic T cells) synthesize purines de novo . Purine synthesis requires two 1C units, which come from serine catabolism and circulating formate. Shortage of 1C units is a potential bottleneck for anti-tumor immunity. Elevating circulating formate drives its usage by tumor-infiltrating T cells. Orally administered methanol functions as a formate pro-drug, with deuteration enabling control of formate-production kinetics. In MC38 tumors, safe doses of methanol raise formate levels and augment anti-PD-1 checkpoint blockade, tripling durable regressions. Thus, 1C deficiency can gate antitumor immunity and this metabolic checkpoint can be overcome with pharmacological 1C supplementation.
Statement of significance: Checkpoint blockade has revolutionized cancer therapy. Durable tumor control, however, is achieved in only a minority of patients. We show that the efficacy of anti-PD-1 blockade can be enhanced by metabolic supplementation with one-carbon donors. Such donors support nucleotide synthesis in tumor-infiltrating T cells and merit future clinical evaluation.

DOI: https://doi.org/10.1101/2023.11.01.565193
Cell Rep. 2023 Nov 14. pii: S2211-1247(23)01438-9. [Epub ahead of print]42(11): 113426

p53-responsive CMBL reprograms glucose metabolism and suppresses cancer development by destabilizing phosphofructokinase PFKP.

Yingdan Huang, Chen Xiong, Chunmeng Wang, Jun Deng, Zhixiang Zuo, Huijing Wu, Jianping Xiong, Xiaohua Wu, Hua Lu, Qian Hao, Xiang Zhou.

  Aerobic glycolysis is critical for cancer progression and can be exploited in cancer therapy. Here, we report that the human carboxymethylenebutenolidase homolog (carboxymethylenebutenolidase-like [CMBL]) acts as a tumor suppressor by reprogramming glycolysis in colorectal cancer (CRC). The anti-cancer action of CMBL is mediated through its interactions with the E3 ubiquitin ligase TRIM25 and the glycolytic enzyme phosphofructokinase-1 platelet type (PFKP). Ectopic CMBL enhances TRIM25 binding to PFKP, leading to the ubiquitination and proteasomal degradation of PFKP. Interestingly, CMBL is transcriptionally activated by p53 in response to genotoxic stress, and p53 activation represses glycolysis by promoting PFKP degradation. Remarkably, CMBL deficiency, which impairs p53's ability to inhibit glycolysis, makes tumors more sensitive to a combination therapy involving the glycolysis inhibitor 2-deoxyglucose. Taken together, our study demonstrates that CMBL suppresses CRC growth by inhibiting glycolysis and suggests a potential combination strategy for the treatment of CMBL-deficient CRC.

Keywords:  CMBL; CP: Cancer; CP: Metabolism; PFKP; TRIM25; cancer therapy; colorectal cancer; glycolysis; p53

DOI:  https://doi.org/10.1016/j.celrep.2023.113426
Biomed Pharmacother. 2023 Nov 15. pii: S0753-3322(23)01690-6. [Epub ahead of print]169 115892

The mitochondrial regulation in ferroptosis signaling pathway and its potential strategies for cancer.

Kai Sun, Yuan Zhi, Wenhao Ren, Shaoming Li, Xiaoqing Zhou, Ling Gao, Keqian Zhi.

  Ferroptosis is an iron-dependent regulated cell death, mainly manifested by the production of reactive oxygen species and accumulation of lipid peroxides. It is distinct from other forms of cell death with regard to morphology and biochemistry, particularly in disrupting mitochondrial function. Mitochondria are essential compartments where the organism generates energy and are closely associated with the fate of ferroptosis. Currently, researchers focus on the potential value of ferroptosis and mitochondria for overcoming drug sensitivity and assisting in cancer therapy. In this review, we summarize the main mechanisms of ferroptosis (the GPX4-realated pathway, FSP1-related pathway, and iron metabolism pathway) and the functions and regulating pathways of mitochondria (the TCA cycle, oxidative phosphorylation, mitochondrial regulation of iron ions, and mtDNA) in ferroptosis. We believe that exploring the role of mitochondria in ferroptosis will help us understand the potential regulatory mechanisms of ferroptosis in cancer and help us find new therapeutic targets.

Keywords:  Cancer therapeutic strategy; Cell death; Ferroptosis; Mitochondria; Molecular mechanism

DOI:  https://doi.org/10.1016/j.biopha.2023.115892
Cancer Res. 2023 Nov 14.

Lineage Plasticity: the New Cancer Hallmark on the Block.

Arnav Mehta, Ben Z Stanger.

Plasticity refers to the ability of cells to adopt a spectrum of states or phenotypes. In cancer, it is a critical contributor to tumor initiation, progression, invasiveness, and therapy resistance, and it has recently been recognized as an emerging cancer hallmark. Plasticity can occur as a result of cell-intrinsic factors (e.g. genetic, transcriptional or epigenetic fluctuations), or through cell-extrinsic cues (e.g. signaling from components of the tumor microenvironment (TME) or selective pressure from therapy). Over the past decade, technological advances, analysis of patient samples, and studies in mouse model systems have led to a deeper understanding of how such plastic states come about. In this review, we discuss: (i) the definition of plasticity; (ii) methods to measure and quantify plasticity; (iii) the clinical relevance of plasticity; and (iv) therapeutic hypotheses to modulate plasticity in the clinic.

DOI: https://doi.org/10.1158/0008-5472.CAN-23-1067
STAR Protoc. 2023 Nov 16. pii: S2666-1667(23)00650-0. [Epub ahead of print]4(4): 102683

Quantification of cell death and proliferation of patient-derived ovarian cancer organoids through 3D imaging and image analysis.

Aikaterini Skorda, Anna Røssberg Lauridsen, Kaisa Huhtinen, Alexandra Lahtinen, Wojciech Senkowski, Jaana Oikkonen, Johanna Hynninen, Sampsa Hautaniemi, Tuula Kallunki.

  Patient-derived organoids (PDOs) are ideal ex vivo model systems to study cancer progression and drug resistance mechanisms. Here, we present a protocol for measuring drug efficacy in three-dimensional (3D) high-grade serous ovarian cancer PDO cultures through quantification of cytotoxicity using propidium iodide incorporation in dead cells. We also provide detailed steps to analyze proliferation of PDOs using the Ki67 biomarker. We describe steps for sample processing, immunofluorescent staining, high-throughput confocal imaging, and image-based quantification for 3D cultures. For complete details on the use and execution of this protocol, please refer to Lahtinen et al. (2023).1.

Keywords:  Cancer; Cell Biology; High-Throughput Screening; Organoids

DOI:  https://doi.org/10.1016/j.xpro.2023.102683
ChemMedChem. 2023 Nov 16. e202300442

Identification of a selective FLT3 inhibitor with low activity against VEGFR, FGFR, PDGFR, c-KIT, and RET anti-targets.

Herman O Sintim, Desmond Akwata, Allison L Kempen, Neetu Dayal, Nickolas R Brauer.

  FLT3 is mainly expressed in immune and various cancer cells and is a drug target for acute myeloid leukemia (AML). Recently, FLT3 has also been identified as a potential target for treating chronic pain. Most FLT3 inhibitors (FLT3i) identified to date, including approved drugs such as gilteritinib, midostaurin, ponatinib, quizartinib, and FLT3i in clinical trials, such as quizartinib and crenolanib, also inhibit closely-related kinases that are important for immune (c-KIT), cardiovascular (KDR/VEGFR2, FGFR, PDGFR) or kidney (RET) functions. While the aforementioned FLT3i may increase survival rates in AML, they are neither ideal for AML maintenance therapy nor for non-oncology applications, such as for the treatment of chronic pain, due to their promiscuous inhibition of many kinase anti-targets. Here, we report the identification of new FLT3i compounds that have low activities against kinases that have traditionally been difficult to differentiate from FLT3 inhibition, such as KDR/VEGFR, FGFR, PGFR, c-KIT, and RET. These selective compounds could be valuable chemical probes for studying FLT3 biology in the context of chronic pain and/or may represent good starting points to develop well-tolerated FLT3 therapeutics for non-oncology indications or for maintenance therapy for AML.

Keywords:  Anti-target; Chronic pain; Leukemia; Selective FLT3 inhibitor

DOI:  https://doi.org/10.1002/cmdc.202300442
Int J Mol Sci. 2023 Nov 01. pii: 15861. [Epub ahead of print]24(21):

Establishment and Comprehensive Molecular Characterization of an Immortalized Glioblastoma Cell Line from a Brazilian Patient.

Fernanda F da Silva, Fernanda C S Lupinacci, Bruno D S Elias, Adriano O Beserra, Paulo Sanematsu, Martin Roffe, Leslie D Kulikowski, Felipe D'almeida Costa, Tiago G Santos, Glaucia N M Hajj.

  Glioblastoma (GBM) is the most common and aggressive primary brain tumor in adults, with few effective treatment strategies. The research on the development of new treatments is often constrained by the limitations of preclinical models, which fail to accurately replicate the disease's essential characteristics. Herein, we describe the obtention, molecular, and functional characterization of the GBM33 cell line. This cell line belongs to the GBM class according to the World Health Organization 2021 Classification of Central Nervous System Tumors, identified by methylation profiling. GBM33 expresses the astrocytic marker GFAP, as well as markers of neuronal origin commonly expressed in GBM cells, such as βIII-tubulin and neurofilament. Functional assays demonstrated an increased growth rate when compared to the U87 commercial cell line and a similar sensitivity to temozolamide. GBM33 cells retained response to serum starvation, with reduced growth and diminished activation of the Akt signaling pathway. Unlike LN-18 and LN-229 commercial cell lines, GBM33 is able to produce primary cilia upon serum starvation. In summary, the successful establishment and comprehensive characterization of this GBM cell line provide researchers with invaluable tools for studying GBM biology, identifying novel therapeutic targets, and evaluating the efficacy of potential treatments.

Keywords:  Akt; cell lines; copy number variation; glioblastoma; mTOR; methylation profile; primary cilia

DOI:  https://doi.org/10.3390/ijms242115861