bims-medica 2023-10-15 papers

bims-medica

Biomed News

on Metabolism and diet in cancer

Issue of 2023–10–15
29 papers selected by
Brett Chrest, East Carolina University

Cancer Metabolism as a Therapeutic Target and Review of Interventions.
Hepatic safety profile of pancreatic cancer‑bearing mice fed a ketogenic diet in combination with gemcitabine.
The Physiological and Pathological Role of Acyl-CoA Oxidation.
Combined inhibition of pyruvate dehydrogenase kinase 1 and lactate dehydrogenase a induces metabolic and signaling reprogramming and enhances lung adenocarcinoma cell killing.
Arginine reprograms metabolism in liver cancer via RBM39.
Ketogenic Diet and Multiple Health Outcomes: An Umbrella Review of Meta-Analysis.
Positive regulation of oxidative phosphorylation by nuclear myosin 1 protects cells from metabolic reprogramming and tumorigenesis in mice.
Hypoxia and lactate influence VOC production in A549 lung cancer cells.
The Pro-Oncogenic Protein IF1 Promotes Proliferation of Anoxic Cancer Cells during Re-Oxygenation.
Inhibition of mitochondrial fission activates glycogen synthesis to support cell survival in colon cancer.
Targeting pancreatic cancer metabolic dependencies through glutamine antagonism.
Optimal control strategies for SGLT2 inhibitors as a novel anti-tumor agent and their effect on human breast cancer cells with the effect of time delay and hyperglycemia.
Multispectral Imaging of Metabolic Fluorophores: Comparing In Vivo and Fresh Ex Vivo Tissue.
The yin and yang of itaconate metabolism and its impact on the tumor microenvironment.
Succinate metabolism: a promising therapeutic target for inflammation, ischemia/reperfusion injury and cancer.
NOX2 control over energy metabolism plays a role in acute myeloid leukaemia prognosis and survival.
Metabolic reprogramming induced by DCA enhances cisplatin sensitivity through increasing mitochondrial oxidative stress in cholangiocarcinoma.
Lactate oxidase nanocapsules boost T cell immunity and efficacy of cancer immunotherapy.
Role of Mitochondrial Dysfunction in Cellular Lipid Homeostasis and Disease.
Engineering dense tumor constructs via cellular contraction of extracellular matrix hydrogels.
Demonstrating drug treatment efficacies by monitoring superoxide dynamics in human lung cancer cells with time-lapse fluorescence microscopy.
Glutamine metabolism in tumor metastasis: Genes, mechanisms and the therapeutic targets.
Tumor microenvironment diversity and plasticity in cancer multidrug resistance.
Deletion of PGAM5 Downregulates FABP1 and Attenuates Long-Chain Fatty Acid Uptake in Hepatocellular Carcinoma.
Profiling ovarian cancer tumor and microenvironment during disease progression for cell-based immunotherapy design.
Forward genetic screens identify mechanisms of resistance to small molecule lactate dehydrogenase inhibitors.
Near-Infrared Imaging of Colonic Adenomas In Vivo Using Orthotopic Human Organoids for Early Cancer Detection.
Use of patient-derived explants as a preclinical model for precision medicine in colorectal cancer: A scoping review.
Quantifying intracellular glucose levels when yeast is grown in glucose media.

Nutrients. 2023 Oct 01. pii: 4245. [Epub ahead of print]15(19):

Cancer Metabolism as a Therapeutic Target and Review of Interventions.

Matthew T J Halma, Jack A Tuszynski, Paul E Marik.

  Cancer is amenable to low-cost treatments, given that it has a significant metabolic component, which can be affected through diet and lifestyle change at minimal cost. The Warburg hypothesis states that cancer cells have an altered cell metabolism towards anaerobic glycolysis. Given this metabolic reprogramming in cancer cells, it is possible to target cancers metabolically by depriving them of glucose. In addition to dietary and lifestyle modifications which work on tumors metabolically, there are a panoply of nutritional supplements and repurposed drugs associated with cancer prevention and better treatment outcomes. These interventions and their evidentiary basis are covered in the latter half of this review to guide future cancer treatment.

Keywords:  Warburg effect; cancer metabolism; glycolysis; ketogenic diet; lifestyle interventions; repurposed drugs

DOI:  https://doi.org/10.3390/nu15194245
Oncol Lett. 2023 Nov;26(5): 479

Hepatic safety profile of pancreatic cancer‑bearing mice fed a ketogenic diet in combination with gemcitabine.

Natalia E Cortez, Cecilia Rodriguez Lanzi, Payam Vahmani, Karen Matsukuma, Gerardo G Mackenzie.

  Ketogenic diets (KDs) are actively being evaluated for their potential anticancer effects. Although KDs are generally considered safe, their safety profile when combined with chemotherapy remains unknown. It is known that a KD enhances the anticancer effect of gemcitabine (2',2'-difluoro-2'-deoxycytidine) in LSL-KrasLSL-G12D/+Trp53R172H/+Pdx-1-Cre (KPC) tumor-bearing mice. In the present study, whether a KD in combination with gemcitabine affected the liver safety profile in KPC mice was evaluated. For this purpose, male and female pancreatic tumor-bearing KPC mice were allocated to a control diet (CD; % kcal: 20% fat, 65% carbohydrate, 15% protein) + gemcitabine [control plus gemcitabine group (CG)] or a KD (% kcal: 84% fat, 15% protein, 1% carbohydrate) + gemcitabine [ketogenic plus gemcitabine group (KG)] for two months. After two months of treatment, no significant differences in body weight were observed between CGs and KGs. Moreover, the KD did not significantly alter the serum protein expression levels of liver enzymes, including aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase. In addition, the KD did not alter markers of liver-lipid accumulation as well as serum cholesterol and triglyceride levels, compared with the CG-treated group. Upon histologic examination, steatosis was rare, with no notable differences between treatment groups. When examining liver fatty acid composition, KD treatment significantly increased the content of saturated fatty acids and significantly decreased levels of cis-monounsaturated fatty acids compared with the CG. Finally, the KD did not affect liver markers of inflammation and oxidative stress, nor the protein expression levels of enzymes involved in ketone bodies, such as 3-hydroxy-3-methylglutaryl-CoA lyase and hidroximetilglutaril-CoA sintasa, and glucose metabolism, such as hexokinase 2, pyruvate dehydrogenase and phosphofructokinase. In summary, a KD in combination with gemcitabine appears to be safe, with no apparent hepatotoxicity and these data support the further evaluation of a KD as an adjuvant dietary treatment for pancreatic cancer.

Keywords:  KPC mice; gemcitabine; ketogenic diet; liver steatosis; liver toxicity; pancreatic cancer

DOI:  https://doi.org/10.3892/ol.2023.14067
Int J Mol Sci. 2023 Oct 03. pii: 14857. [Epub ahead of print]24(19):

The Physiological and Pathological Role of Acyl-CoA Oxidation.

Sylwia Szrok-Jurga, Aleksandra Czumaj, Jacek Turyn, Areta Hebanowska, Julian Swierczynski, Tomasz Sledzinski, Ewa Stelmanska.

  Fatty acid metabolism, including β-oxidation (βOX), plays an important role in human physiology and pathology. βOX is an essential process in the energy metabolism of most human cells. Moreover, βOX is also the source of acetyl-CoA, the substrate for (a) ketone bodies synthesis, (b) cholesterol synthesis, (c) phase II detoxication, (d) protein acetylation, and (d) the synthesis of many other compounds, including N-acetylglutamate-an important regulator of urea synthesis. This review describes the current knowledge on the importance of the mitochondrial and peroxisomal βOX in various organs, including the liver, heart, kidney, lung, gastrointestinal tract, peripheral white blood cells, and other cells. In addition, the diseases associated with a disturbance of fatty acid oxidation (FAO) in the liver, heart, kidney, lung, alimentary tract, and other organs or cells are presented. Special attention was paid to abnormalities of FAO in cancer cells and the diseases caused by mutations in gene-encoding enzymes involved in FAO. Finally, issues related to α- and ω- fatty acid oxidation are discussed.

Keywords:  acyl-CoA; beta-oxidation; fatty acid metabolism; peroxisomal fatty acid oxidation

DOI:  https://doi.org/10.3390/ijms241914857
Cancer Lett. 2023 Oct 05. pii: S0304-3835(23)00376-2. [Epub ahead of print] 216425

Combined inhibition of pyruvate dehydrogenase kinase 1 and lactate dehydrogenase a induces metabolic and signaling reprogramming and enhances lung adenocarcinoma cell killing.

Yan Zhou, Yizhen Guo, Maoxin Ran, Wenying Shan, Carlotta Granchi, Elisa Giovannetti, Filippo Minutolo, Godefridus J Peters, Kin Yip Tam.

  Lung adenocarcinoma (LUAD) is one of the most prevalent and aggressive types of lung cancer. Metabolic reprogramming plays a critical role in the development and progression of LUAD. Pyruvate dehydrogenase kinase 1 (PDK1) and lactate dehydrogenase A (LDHA) are two key enzymes involved in glucose metabolism, whilst their aberrant expressions are often associated with tumorigenesis. Herein, we investigated the anticancer effects of combined inhibition of PDK1 and LDHA in LUAD in vitro and in vivo and its underlying mechanisms of action. The combination of a PDK1 inhibitor, 64, and a LDHA inhibitor, NHI-Glc-2, led to a synergistic growth inhibition in 3 different LUAD cell lines and more than additively suppressed tumor growth in the LUAD xenograft H1975 model. This combination also inhibited cellular migration and colony formation, while it induced a metabolic shift from glycolysis to oxidative phosphorylation (OXPHOS) resulting in mitochondrial depolarization and apoptosis in LUAD cells. These effects were related to modulation of multiple cell signaling pathways, including AMPK, RAS/ERK, and AKT/mTOR. Our findings demonstrate that simultaneous inhibition of multiple glycolytic enzymes (PDK1 and LDHA) is a promising novel therapeutic approach for LUAD.

Keywords:  Anticancer; Combination treatment; Non-small cell lung cancer; Warburg effect

DOI:  https://doi.org/10.1016/j.canlet.2023.216425
Cell. 2023 Sep 26. pii: S0092-8674(23)01032-2. [Epub ahead of print]

Arginine reprograms metabolism in liver cancer via RBM39.

Dirk Mossmann, Christoph Müller, Sujin Park, Brendan Ryback, Marco Colombi, Nathalie Ritter, Diana Weißenberger, Eva Dazert, Mairene Coto-Llerena, Sandro Nuciforo, Lauriane Blukacz, Caner Ercan, Veronica Jimenez, Salvatore Piscuoglio, Fatima Bosch, Luigi M Terracciano, Uwe Sauer, Markus H Heim, Michael N Hall.

  Metabolic reprogramming is a hallmark of cancer. However, mechanisms underlying metabolic reprogramming and how altered metabolism in turn enhances tumorigenicity are poorly understood. Here, we report that arginine levels are elevated in murine and patient hepatocellular carcinoma (HCC), despite reduced expression of arginine synthesis genes. Tumor cells accumulate high levels of arginine due to increased uptake and reduced arginine-to-polyamine conversion. Importantly, the high levels of arginine promote tumor formation via further metabolic reprogramming, including changes in glucose, amino acid, nucleotide, and fatty acid metabolism. Mechanistically, arginine binds RNA-binding motif protein 39 (RBM39) to control expression of metabolic genes. RBM39-mediated upregulation of asparagine synthesis leads to enhanced arginine uptake, creating a positive feedback loop to sustain high arginine levels and oncogenic metabolism. Thus, arginine is a second messenger-like molecule that reprograms metabolism to promote tumor growth.

Keywords:  AGMAT; ARG1; ASNS; RBM39; arginine; hepatocellular carcinoma; indisulam; metabolism

DOI:  https://doi.org/10.1016/j.cell.2023.09.011
Nutrients. 2023 Sep 27. pii: 4161. [Epub ahead of print]15(19):

Ketogenic Diet and Multiple Health Outcomes: An Umbrella Review of Meta-Analysis.

Shiyun Chen, Xin Su, Yonghui Feng, Ruojie Li, Minqi Liao, Laina Fan, Jiazi Liu, Shasha Chen, Shiwen Zhang, Jun Cai, Sui Zhu, Jianxiang Niu, Yanbin Ye, Kenneth Lo, Fangfang Zeng.

  Numerous studies have examined the effects of ketogenic diets (KD) on health-related outcomes through meta-analyses. However, the presence of biases may compromise the reliability of conclusions. Therefore, we conducted an umbrella review to collate and appraise the strength of evidence on the efficacy of KD interventions. We conducted a comprehensive search on PubMed, EMBASE, and the Cochrane Database until April 2023 to identify meta-analyses that investigated the treatment effects of KD for multiple health conditions, which yielded 23 meta-analyses for quantitative analyses. The evidence suggests that KD could increase the levels of low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-C), the respiratory exchange rate (RER), and could decrease total testosterone and testosterone levels (all p-random effects: <0.05). The combination of KD and physical activity can significantly reduce body weight and increase the levels of LDL-C and cortisol. In addition, KD was associated with seizure reduction in children, which can be explained by the ketosis state as induced by the diet. Furthermore, KD demonstrated a better alleviation effect in refractory childhood epilepsy, in terms of median effective rates for seizure reduction of ≥50%, ≥90%, and seizure freedom. However, the strength of evidence supporting the aforementioned associations was generally weak, thereby challenging their credibility. Consequently, future studies should prioritize stringent research protocols to ascertain whether KD interventions with longer intervention periods hold promise as a viable treatment option for various diseases.

Keywords:  cancer; ketogenic diets; meta-analysis; obesity; overweight; seizure reduction; umbrella review

DOI:  https://doi.org/10.3390/nu15194161
Nat Commun. 2023 Oct 10. 14(1): 6328

Positive regulation of oxidative phosphorylation by nuclear myosin 1 protects cells from metabolic reprogramming and tumorigenesis in mice.

Tomas Venit, Oscar Sapkota, Wael Said Abdrabou, Palanikumar Loganathan, Renu Pasricha, Syed Raza Mahmood, Nadine Hosny El Said, Shimaa Sherif, Sneha Thomas, Salah Abdelrazig, Shady Amin, Davide Bedognetti, Youssef Idaghdour, Mazin Magzoub, Piergiorgio Percipalle.

Metabolic reprogramming is one of the hallmarks of tumorigenesis. Here, we show that nuclear myosin 1 (NM1) serves as a key regulator of cellular metabolism. NM1 directly affects mitochondrial oxidative phosphorylation (OXPHOS) by regulating mitochondrial transcription factors TFAM and PGC1α, and its deletion leads to underdeveloped mitochondria inner cristae and mitochondrial redistribution within the cell. These changes are associated with reduced OXPHOS gene expression, decreased mitochondrial DNA copy number, and deregulated mitochondrial dynamics, which lead to metabolic reprogramming of NM1 KO cells from OXPHOS to aerobic glycolysis.This, in turn, is associated with a metabolomic profile typical for cancer cells, namely increased amino acid-, fatty acid-, and sugar metabolism, and increased glucose uptake, lactate production, and intracellular acidity. NM1 KO cells form solid tumors in a mouse model, suggesting that the metabolic switch towards aerobic glycolysis provides a sufficient carcinogenic signal. We suggest that NM1 plays a role as a tumor suppressor and that NM1 depletion may contribute to the Warburg effect at the onset of tumorigenesis.

DOI: https://doi.org/10.1038/s41467-023-42093-w
Front Mol Biosci. 2023 ;10 1274298

Hypoxia and lactate influence VOC production in A549 lung cancer cells.

Takeshi Furuhashi, Yuki Matsumoto, Ryuga Ishii, Takehito Sugasawa, Shigenori Ota.

  Introduction: Cancer cells emit characteristic volatile organic compounds (VOCs), which are potentially generated from ROS-based lipid peroxidation of polyunsaturated fatty acids. The metabolism of such VOCs and their regulation remain to be fully investigated. In fact, the enzymes involved in the synthesis of these VOCs have not been described yet. Methods: In this study, we firstly conducted in vitro enzyme assays and demonstrated that recombinant alcohol dehydrogenase (ADH) converted Trans 2-hexenal into Trans 2-hexenol. The latter has previously been reported as a cancer VOC. To study VOC metabolism, 14 different culture conditions were compared in view of Trans 2-hexenol production. Results and discussion: The data indicate that hypoxia and the addition of lactate positively influenced Trans 2-hexenol production in A549 cancer cells. The RNAseq data suggested certain gene expressions in the VOC pathway and in lactate signaling, parallel to VOC production. This implies that hypoxia and lactate signaling with a VOC production can be characteristic for cancer in vitro.

Keywords:  cancer metabolism; cellular VOC; hypoxia; lactic acid signaling; lipid peroxidation; lung cancer cell

DOI:  https://doi.org/10.3389/fmolb.2023.1274298
Int J Mol Sci. 2023 Sep 27. pii: 14624. [Epub ahead of print]24(19):

The Pro-Oncogenic Protein IF1 Promotes Proliferation of Anoxic Cancer Cells during Re-Oxygenation.

Riccardo Righetti, Silvia Grillini, Valentina Del Dotto, Anna Costanzini, Francesca Liuzzi, Claudia Zanna, Gianluca Sgarbi, Giancarlo Solaini, Alessandra Baracca.

  Cancer cells overexpress IF1, the endogenous protein that inhibits the hydrolytic activity of ATP synthase when mitochondrial membrane potential (ΔμH+) falls, as in ischemia. Other roles have been ascribed to IF1, but the associated molecular mechanisms are still under debate. We investigated the ability of IF1 to promote survival and proliferation in osteosarcoma and colon carcinoma cells exposed to conditions mimicking ischemia and reperfusion, as occurs in vivo, particularly in solid tumors. IF1-silenced and parental cells were exposed to the FCCP uncoupler to collapse ΔμH+ and the bioenergetics of cell models were validated. All the uncoupled cells preserved mitochondrial mass, but the implemented mechanisms differed in IF1-expressing and IF1-silenced cells. Indeed, the membrane potential collapse and the energy charge preservation allowed an increase in both mitophagy and mitochondrial biogenesis in IF1-expressing cells only. Interestingly, the presence of IF1 also conferred a proliferative advantage to cells highly dependent on oxidative phosphorylation when the uncoupler was washed out, mimicking cell re-oxygenation. Overall, our results indicate that IF1, by allowing energy preservation and promoting mitochondrial renewal, can favor proliferation of anoxic cells and tumor growth. Therefore, hindering the action of IF1 may be promising for the therapy of tumors that rely on oxidative phosphorylation for energy production.

Keywords:  143B osteosarcoma cells; ATP synthase; HCT116 colon carcinoma cells; anoxia; autophagy; biogenesis; metabolism; mitochondria; mitophagy; oxidative phosphorylation

DOI:  https://doi.org/10.3390/ijms241914624
Cell Death Dis. 2023 Oct 10. 14(10): 664

Inhibition of mitochondrial fission activates glycogen synthesis to support cell survival in colon cancer.

Sumati Hasani, Lyndsay E A Young, Warren Van Nort, Moumita Banerjee, Dylan R Rivas, Jinhwan Kim, Xiaopeng Xiong, Ramon C Sun, Matthew S Gentry, Hiromi Sesaki, Tianyan Gao.

Metabolic reprogramming has been recognized as one of the major mechanisms that fuel tumor initiation and progression. Our previous studies demonstrate that activation of Drp1 promotes fatty acid oxidation and downstream Wnt signaling. Here we investigate the role of Drp1 in regulating glycogen metabolism in colon cancer. Knockdown of Drp1 decreases mitochondrial respiration without increasing glycolysis. Analysis of cellular metabolites reveals that the levels of glucose-6-phosphate, a precursor for glycogenesis, are significantly elevated whereas pyruvate and other TCA cycle metabolites remain unchanged in Drp1 knockdown cells. Additionally, silencing Drp1 activates AMPK to stimulate the expression glycogen synthase 1 (GYS1) mRNA and promote glycogen storage. Using 3D organoids from Apcf/f/Villin-CreERT2 models, we show that glycogen levels are elevated in tumor organoids upon genetic deletion of Drp1. Similarly, increased GYS1 expression and glycogen accumulation are detected in xenograft tumors derived from Drp1 knockdown colon cancer cells. Functionally, increased glycogen storage provides survival advantage to Drp1 knockdown cells. Co-targeting glycogen phosphorylase-mediated glycogenolysis sensitizes Drp1 knockdown cells to chemotherapy drug treatment. Taken together, our results suggest that Drp1-loss activates glucose uptake and glycogenesis as compensative metabolic pathways to promote cell survival. Combined inhibition of glycogen metabolism may enhance the efficacy of chemotherapeutic agents for colon cancer treatment.

DOI: https://doi.org/10.1038/s41419-023-06202-3
Nat Cancer. 2023 Oct 09.

Targeting pancreatic cancer metabolic dependencies through glutamine antagonism.

Joel Encarnación-Rosado, Albert S W Sohn, Douglas E Biancur, Elaine Y Lin, Victoria Osorio-Vasquez, Tori Rodrick, Diana González-Baerga, Ende Zhao, Yumi Yokoyama, Diane M Simeone, Drew R Jones, Seth J Parker, Robert Wild, Alec C Kimmelman.

Pancreatic ductal adenocarcinoma (PDAC) cells use glutamine (Gln) to support proliferation and redox balance. Early attempts to inhibit Gln metabolism using glutaminase inhibitors resulted in rapid metabolic reprogramming and therapeutic resistance. Here, we demonstrated that treating PDAC cells with a Gln antagonist, 6-diazo-5-oxo-L-norleucine (DON), led to a metabolic crisis in vitro. In addition, we observed a profound decrease in tumor growth in several in vivo models using sirpiglenastat (DRP-104), a pro-drug version of DON that was designed to circumvent DON-associated toxicity. We found that extracellular signal-regulated kinase (ERK) signaling is increased as a compensatory mechanism. Combinatorial treatment with DRP-104 and trametinib led to a significant increase in survival in a syngeneic model of PDAC. These proof-of-concept studies suggested that broadly targeting Gln metabolism could provide a therapeutic avenue for PDAC. The combination with an ERK signaling pathway inhibitor could further improve the therapeutic outcome.

DOI: https://doi.org/10.1038/s43018-023-00647-3
Comput Biol Med. 2023 Oct 05. pii: S0010-4825(23)01017-X. [Epub ahead of print]166 107552

Optimal control strategies for SGLT2 inhibitors as a novel anti-tumor agent and their effect on human breast cancer cells with the effect of time delay and hyperglycemia.

Abeer Hamdan Alblowy, Normah Maan, Abdulkareem Afolabi Ibrahim.

  Breast cancer is the most frequent cancer in the world, and it continues to have a significant impact on the total number of cancer deaths. Recently, oncology findings hint at the role of excessive glucose in cancer progression and immune cells' suppression. Sequel to this revelation is ongoing researches on possible inhibition of glucose flow into the tumor micro-environment as therapeutics for malignant treatment. In this study, the effect of glucose blockage therapeutics such as SGLT-2 inhibitors drug on the dynamics of normal, tumors and immune cells interaction is mathematically studied. The asymptomatic nature of the breast cancer is factored into the model using time delay. We first investigate the boundedness and non-negativity of the solution. The condition for existence of critical equilibrium point is determined, and its global stability conditions are derived using Lyapunov function. This revealed that a timely administration of the SGLT-2 inhibitors drug can eliminate tumor cells. Secondly, we determine the sufficient and necessary conditions for optimal control strategy of SGLT-2 inhibitors so as to avert side effects on normal cells using a Pontryagin's Minimum Principle. The results showed that if the ingestion rate of the inhibitor drug is equal to the digestion rate, the tumor cells can be completely eliminated within 9 months without side effects. The analytical results were numerically verified and the qualitative views of interacting cells dynamics is showcased.

Keywords:  Breast cancer; Delay model; Hyperglycemia; Optimal control; Sodium glucose transporter-2 inhibitor

DOI:  https://doi.org/10.1016/j.compbiomed.2023.107552
Crit Rev Eukaryot Gene Expr. 2024 ;34(1): 69-74

Multispectral Imaging of Metabolic Fluorophores: Comparing In Vivo and Fresh Ex Vivo Tissue.

Gary E Carver, Sarah A Locknar, Prachi N Ghule, Christopher J Pung, Donald L Weaver, Janet L Stein, Gary S Stein.

The enhanced uptake of glucose by cancer cells via aerobic glycolysis occurs when the lactic acid pathway is favored over the citric acid cycle. The lactic acid cycle in cancer cells influences the cytosolic concentration of metabolic fluorophores including NADH (the reduced form of nicotinamide adenine dinucleotide) and flavin adenine dinucleotide (FAD). In particular, the literature has shown that breast cancer influences the relative magnitude of fluorescence from NADH and FAD. A multispectral imaging system has been developed for rapid non-destructive imaging of intrinsic fluorescence in tissue. This paper compares in vivo data to fresh ex vivo data gathered as a function of time in mouse models. The data indicate that, if measured within 30 min of excision, a cancer diagnosis in fresh ex vivo tissue correlates with a cancer diagnosis in in vivo tissue. These results justify a plan to evaluate fresh ex vivo human tissue to quantify the sensitivity and specificity of the multispectral system.

DOI: https://doi.org/10.1615/CritRevEukaryotGeneExpr.2023049567
Curr Opin Biotechnol. 2023 Oct 06. pii: S0958-1669(23)00106-4. [Epub ahead of print]84 102996

The yin and yang of itaconate metabolism and its impact on the tumor microenvironment.

Fangfang Chen, Birte Dowerg, Thekla Cordes.

The tumor microenvironment (TME) consists of a network of metabolically interconnected tumor and immune cell types. Macrophages influence the metabolic composition within the TME, which directly impacts the metabolic state and drug response of tumors. The accumulation of oncometabolites, such as succinate, fumarate, and 2-hydroxyglutarate, represents metabolic vulnerabilities in cancer that can be targeted therapeutically. Immunometabolites are emerging as metabolic regulators of the TME impacting immune cell functions and cancer cell growth. Here, we discuss recent discoveries on the potential impact of itaconate on the TME. We highlight how itaconate influences metabolic pathways relevant to immune responses and cancer cell proliferation. We also consider the therapeutic implications of manipulating itaconate metabolism as an immunotherapeutic strategy to constrain tumor growth.

DOI: https://doi.org/10.1016/j.copbio.2023.102996
Front Cell Dev Biol. 2023 ;11 1266973

Succinate metabolism: a promising therapeutic target for inflammation, ischemia/reperfusion injury and cancer.

Wenhui Zhang, Ren Lang.

  Succinate serves as an essential circulating metabolite within the tricarboxylic acid (TCA) cycle and functions as a substrate for succinate dehydrogenase (SDH), thereby contributing to energy production in fundamental mitochondrial metabolic pathways. Aberrant changes in succinate concentrations have been associated with pathological states, including chronic inflammation, ischemia/reperfusion (IR) injury, and cancer, resulting from the exaggerated response of specific immune cells, thereby rendering it a central area of investigation. Recent studies have elucidated the pivotal involvement of succinate and SDH in immunity beyond metabolic processes, particularly in the context of cancer. Current scientific endeavors are concentrated on comprehending the functional repercussions of metabolic modifications, specifically pertaining to succinate and SDH, in immune cells operating within a hypoxic milieu. The efficacy of targeting succinate and SDH alterations to manipulate immune cell functions in hypoxia-related diseases have been demonstrated. Consequently, a comprehensive understanding of succinate's role in metabolism and the regulation of SDH is crucial for effectively targeting succinate and SDH as therapeutic interventions to influence the progression of specific diseases. This review provides a succinct overview of the latest advancements in comprehending the emerging functions of succinate and SDH in metabolic processes. Furthermore, it explores the involvement of succinate, an intermediary of the TCA cycle, in chronic inflammation, IR injury, and cancer, with particular emphasis on the mechanisms underlying succinate accumulation. This review critically assesses the potential of modulating succinate accumulation and metabolism within the hypoxic milieu as a means to combat various diseases. It explores potential targets for therapeutic interventions by focusing on succinate metabolism and the regulation of SDH in hypoxia-related disorders.

Keywords:  cancer; immune cells; inflammation; ischemia/reperfusion (IR) injury; succinate; succinate dehydrogenase (SDH)

DOI:  https://doi.org/10.3389/fcell.2023.1266973
Free Radic Biol Med. 2023 Oct 06. pii: S0891-5849(23)00677-9. [Epub ahead of print]209(Pt 1): 18-28

NOX2 control over energy metabolism plays a role in acute myeloid leukaemia prognosis and survival.

Carla Ijurko, Marta Romo-González, Clara García-Calvo, José Luis Sardina, Carmen Sánchez-Bernal, Jesús Sánchez-Yagüe, Bénédicte Elena-Herrmann, Joran Villaret, Catherine Garrel, Julie Mondet, Pascal Mossuz, Ángel Hernández-Hernández.

  Acute myeloid leukaemia (AML) is a highly heterogeneous disease, however the therapeutic approaches have hardly changed in the last decades. Metabolism rewiring and the enhanced production of reactive oxygen species (ROS) are hallmarks of cancer. A deeper understanding of these features could be instrumental for the development of specific AML-subtypes treatments. NADPH oxidases (NOX), the only cellular system specialised in ROS production, are also involved in leukemic metabolism control. NOX2 shows a variable expression in AML patients, so patients can be classified based on such difference. Here we have analysed whether NOX2 levels are important for AML metabolism control. The lack of NOX2 in AML cells slowdowns basal glycolysis and oxidative phosphorylation (OXPHOS), along with the accumulation of metabolites that feed such routes, and a sharp decrease of glutathione. In addition, we found changes in the expression of 725 genes. Among them, we have discovered a panel of 30 differentially expressed metabolic genes, whose relevance was validated in patients. This panel can segregate AML patients according to CYBB expression, and it can predict patient prognosis and survival. In summary, our data strongly support the relevance of NOX2 for AML metabolism, and highlights the potential of our discoveries in AML prognosis.

Keywords:  Acute myeloid leukaemia; CYBB; Metabolism; NADPH oxidase; NOX2

DOI:  https://doi.org/10.1016/j.freeradbiomed.2023.10.013
Front Pharmacol. 2023 ;14 1128312

Metabolic reprogramming induced by DCA enhances cisplatin sensitivity through increasing mitochondrial oxidative stress in cholangiocarcinoma.

Hanjiao Qin, Ge Zheng, Qiao Li, Luyan Shen.

  Background: Cholangiocarcinoma has obvious primary multidrug resistance and is generally resistant to cisplatin and other chemotherapy drugs and high glycolytic levels may be associated with chemotherapy resistance of cholangiocarcinoma cells. Dichloroacetate (DCA) is a specific inhibitor of PDK, which can promote mitochondrial aerobic oxidation process by activating PDH. In the past few years, there have been an increasing number of studies supporting the action of DCA against cancer, which also provided evidence for targeting metabolism to enhance the efficacy of cholangiocarcinoma chemotherapy. Methods: Glucose uptake and lactic acid secretion were used to detect cell metabolism level. Cell apoptosis and cell cycle were detected to confirm cell fate induced by cisplatin combined with DCA. Mito-TEMPO was used to inhibit mtROS to explore the relationship between oxidative stress and cell cycle arrest induced by DCA under cisplatin stress. Finally, PCR array and autophagy inhibitor CQ were used to explore the potential protective mechanism under cell stress. Results: DCA changed the metabolic model from glycolysis to aerobic oxidation in cholangiocarcinoma cells under cisplatin stress. This metabolic reprogramming increased mitochondrial reactive oxygen species (mtROS) levels, which promoted cell cycle arrest, increased the expression of antioxidant genes and activated autophagy. Inhibition of autophagy further increased the synergistic effect of DCA and cisplatin. Conclusion: DCA increased cisplatin sensitivity in cholangiocarcinoma cells via increasing the mitochondria oxidative stress and cell growth inhibition. Synergistic effects of DCA and CQ were observed in cholangiocarcinoma cells, which further increased the cisplatin sensitivity via both metabolic reprogramming and inhibition of the stress response autophagy.

Keywords:  DCA; autophagy; cholangiocarcinoma; cisplatin sensitivity; metabolic reprogramming; redox homeostasis

DOI:  https://doi.org/10.3389/fphar.2023.1128312
Sci Transl Med. 2023 Oct 11. 15(717): eadd2712

Lactate oxidase nanocapsules boost T cell immunity and efficacy of cancer immunotherapy.

Zheng Cao, Duo Xu, Jeffrey Harding, Wenting Chen, Xiangsheng Liu, Zi Wang, Lan Wang, Tong Qi, Shilin Chen, Xinheng Guo, Irvin S Y Chen, Jimin Guo, Yunfeng Lu, Jing Wen.

Cancer immunotherapy has reshaped the landscape of cancer treatment. However, its efficacy is still limited by tumor immunosuppression associated with the excessive production of lactate by cancer cells. Although extensive efforts have been made to reduce lactate concentrations through inhibition of lactate dehydrogenase, such inhibitors disrupt the metabolism of healthy cells, causing severe nonspecific toxicity. We report herein a nanocapsule enzyme therapeutic based on lactate oxidase, which reduces lactate concentrations and releases immunostimulatory hydrogen peroxide, averting tumor immunosuppression and improving the efficacy of immune checkpoint blockade treatment. As demonstrated in a murine melanoma model and a humanized mouse model of triple-negative breast cancer, this enzyme therapeutic affords an effective tool toward more effective cancer immunotherapy.

DOI: https://doi.org/10.1126/scitranslmed.add2712
Discov Med. 2023 Oct;35(178): 653-663

Role of Mitochondrial Dysfunction in Cellular Lipid Homeostasis and Disease.

Siresha Bathina, Undurti N Das.

  Mitochondria-associated membranes (MAMs) play a significant role in multiple cellular processes including lipid metabolism and neuronal survival. Fatty acids constitute 80% of the dry mass of the brain and are vital for life. Apart from mitochondrial β-oxidation, fatty acids are metabolized in part by peroxisomes to regulate the generation of acyl Coenzyme A and adenosine triphosphate (ATP). Ablation of mitochondria and its associated genes tether endoplasmic reticulum (ER)-Mitochondria contact and results in loss of function leading to aberrant lipid metabolism. Additionally, an increase in reactive oxygen species (ROS) levels along with free radicals' generation may lead to alteration in the integrity of membrane phospholipids, proteins, and DNA. Hence, it is critical to understand the effect of structural and functional aspects of mitochondria on lipid homeostasis. This review explains the role of mitochondrial dysfunction in lipid metabolism and its impact on various neurodegenerative diseases and metabolic disorders.

Keywords:  lipid metabolism; mitochondria dysfunction; neurodegenerative disease

DOI:  https://doi.org/10.24976/Discov.Med.202335178.64
Biotechnol Bioeng. 2023 Oct 11.

Engineering dense tumor constructs via cellular contraction of extracellular matrix hydrogels.

Jae A McKee, Elisabet A Olsen, Gideon Wills Kpeli, Moriah R Brooks, Mohamadreza Beitollahpoor, Noshir S Pesika, Matthew E Burow, Mark J Mondrinos.

  Physical characteristics of solid tumors such as dense internal microarchitectures and pathological stiffness influence cancer progression and treatment. While it is routine to engineer culture substrates and scaffolds with elastic moduli that approximate tumors, these models often fail to capture characteristic internal microarchitectures such as densely compacted concentric ECM fibers at the stromal interface. Contractile mesenchymal cells can solve this engineering challenge by deforming, contracting, and compacting extracellular matrix (ECM) hydrogels to decrease tissue volume and increase tissue density. Here we demonstrate that allowing human fibroblasts of varying origins to freely contract collagen type I-containing hydrogels co-seeded with carcinoma cell spheroids produces a tissue engineered construct with structural features that mimic dense solid tumors in vivo. Morphometry and mechanical testing were conducted in tandem with biochemical analysis of proliferation and viability to confirm that dense carcinoma constructs engineered using this approach capture relevant physical characteristics of solid carcinomas in a tractable format that preserves viability and is amenable to extended culture. The reported method is adaptable to the use of multiple mesenchymal cell types and the inclusion of fibrin in the ECM combined with seeding of endothelial cells to produce prevascularized constructs. The physical dense carcinoma constructs engineered using this approach may provide more clinically relevant venues for studying cancer pathophysiology and the challenges associated with the delivery of macromolecular drugs and cellular immunotherapies to solid tumors.

Keywords:  cancer; cell contractility; collagen; fibroblasts; tissue engineering; tumor stroma

DOI:  https://doi.org/10.1002/bit.28561
J Biophotonics. 2023 Oct 11. e202300331

Demonstrating drug treatment efficacies by monitoring superoxide dynamics in human lung cancer cells with time-lapse fluorescence microscopy.

Shalaka Konjalwar, Busenur Ceyhan, Oscar Rivera, Parisa Nategh, Mehrnoosh Neghabi, Mirjana Pavlovic, Shailaja Allani, Mahsa Ranji.

  Metformin hydrochloride, an antihyperglycemic agent, and sulindac, a nonsteroidal anti-inflammatory drug, are FDA-approved drugs known to exert anticancer effects. Previous studies demonstrated sulindac and metformin's anticancer properties through mitochondrial dysfunction and inhibition of mitochondrial electron transport chain (ETC) complex I and key signaling pathways. In this study, various drugs were administered to A549 lung cancer cells, and results revealed that a combination of sulindac and metformin enhanced cell death compared to the administration of the drugs separately. To measure superoxide production over time, we employed a time-lapse fluorescence imaging technique using mitochondrial-targeted hydroethidine. Fluorescence microscopy data showed the most significant increases in superoxide production in the combination treatment of metformin and sulindac. Results showed significant differences between the combined drug treatment and control groups and between the positive control and control groups. This approach can be utilized to quantify the anticancer efficacy of drugs, creating possibilities for additional therapeutic options. This article is protected by copyright. All rights reserved.

Keywords:  MitoSOX red; fluorescence microscopy; metformin; oxidative stress; sulindac; superoxide; time-lapse imaging

DOI:  https://doi.org/10.1002/jbio.202300331
Heliyon. 2023 Oct;9(10): e20656

Glutamine metabolism in tumor metastasis: Genes, mechanisms and the therapeutic targets.

Xugang Zhong, Zeju He, Li Yin, Yong Fan, Yu Tong, Yao Kang, Qing Bi.

  Cancer cells frequently change their metabolism from aerobic glycolysis to lipid metabolism and amino acid metabolism to adapt to the malignant biological behaviours of infinite proliferation and distant metastasis. The significance of metabolic substances and patterns in tumour cell metastasis is becoming increasingly prominent. Tumour metastasis involves a series of significant steps such as the shedding of cancer cells from a primary tumour, resistance to apoptosis, and colonisation of metastatic sites. However, the role of glutamine in these processes remains unclear. This review summarises the key enzymes and transporters involved in glutamine metabolism that are related to the pathogenesis of malignant tumour metastasis. We also list the roles of glutamine in resisting oxidative stress and promoting immune escape. Finally, the significance of targeting glutamine metabolism in inhibiting tumour metastasis was proposed, research in this field improving our understanding of amino acid metabolism rewiring and simultaneously bringing about new and exciting therapeutic prospects.

Keywords:  Amino acid metabolism; Cancer metastasis; Glutamine; Metabolic therapy; Precision medicine

DOI:  https://doi.org/10.1016/j.heliyon.2023.e20656
Biochim Biophys Acta Rev Cancer. 2023 Oct 11. pii: S0304-419X(23)00146-4. [Epub ahead of print] 188997

Tumor microenvironment diversity and plasticity in cancer multidrug resistance.

Zhi Li, Peihao Yin.

  Multidrug resistance (MDR) poses a significant obstacle to effective cancer treatment, and the tumor microenvironment (TME) is crucial for MDR development and reversal. The TME plays an active role in promoting MDR through several pathways. However, a promising therapeutic approach for battling MDR involves targeting specific elements within the TME. Therefore, this comprehensive review elaborates on the research developments regarding the dual role of the TME in promoting and reversing MDR in cancer. Understanding the complex role of the TME in promoting and reversing MDR is essential to developing effective cancer therapies. Utilizing the adaptability of the TME by targeting novel TME-specific factors, utilizing combination therapies, and employing innovative treatment strategies can potentially combat MDR and achieve personalized treatment outcomes for patients with cancer.

Keywords:  Bufalin; Cancer; Hypoxia-inducible factors; Multidrug resistance; Tumor microenvironment

DOI:  https://doi.org/10.1016/j.bbcan.2023.188997
Cancers (Basel). 2023 Sep 29. pii: 4796. [Epub ahead of print]15(19):

Deletion of PGAM5 Downregulates FABP1 and Attenuates Long-Chain Fatty Acid Uptake in Hepatocellular Carcinoma.

Ganesan Muthusamy, Chin-Chi Liu, Andrea N Johnston.

  Phosphoglycerate mutase 5 (PGAM5) is a Ser/His/Thr phosphatase responsible for regulating mitochondrial homeostasis. Overexpression of PGAM5 is correlated with a poor prognosis in hepatocellular carcinoma, colon cancer, and melanoma. In hepatocellular carcinoma, silencing of PGAM5 reduces growth, which has been attributed to decreased mitophagy and enhanced apoptosis. Yet in colon cancer, PGAM5's pro-tumor survival effect is correlated to lipid metabolism. We sought to identify whether deletion of PGAM5 modulated lipid droplet accrual in hepatocellular carcinoma. HepG2 and Huh7 PGAM5 knockout cell lines generated using CRISPR/Cas9 technology were used to measure cell growth, cellular ATP, and long-chain fatty acid uptake. Expression of hepatocellular fatty acid transporters, cluster of differentiation 36 (CD36), solute carrier family 27 member 2 (SLC27A2), solute carrier family 27 member 5 (SLC27A5), and fatty acid binding protein 1 (FABP1) was measured by quantitative PCR and Western blot. We found that deletion of PGAM5 attenuates hepatocellular carcinoma cell growth and ATP production. Further, PGAM5 knockout ameliorates palmitate-induced steatosis and reduces expression of FABP1 in HepG2 and Huh7 cell lines. PGAM5's role in hepatocellular carcinoma includes regulation of fatty acid metabolism, which may be related to expression of the fatty acid transporter, FABP1.

Keywords:  fatty acid transporters; liver cancer; long-chain fatty acids

DOI:  https://doi.org/10.3390/cancers15194796
iScience. 2023 Oct 20. 26(10): 107952

Profiling ovarian cancer tumor and microenvironment during disease progression for cell-based immunotherapy design.

Yan-Ruide Li, Christopher J Ochoa, Yichen Zhu, Adam Kramer, Matthew Wilson, Ying Fang, Yuning Chen, Tanya Singh, Gabriella Di Bernardo, Enbo Zhu, Derek Lee, Neda A Moatamed, Joanne Bando, Jin J Zhou, Sanaz Memarzadeh, Lili Yang.

  Ovarian cancer (OC) is highly lethal due to late detection and frequent recurrence. Initial treatments, comprising surgery and chemotherapy, lead to disease remission but are invariably associated with subsequent relapse. The identification of novel therapies and an improved understanding of the molecular and cellular characteristics of OC are urgently needed. Here, we conducted a comprehensive analysis of primary tumor cells and their microenvironment from 16 chemonaive and 10 recurrent OC patient samples. Profiling OC tumor biomarkers allowed for the identification of potential molecular targets for developing immunotherapies, while profiling the microenvironment yielded insights into its cellular composition and property changes between chemonaive and recurrent samples. Notably, we identified CD1d as a biomarker of the OC microenvironment and demonstrated its targeting by invariant natural killer T (iNKT) cells. Overall, our study presents a comprehensive immuno-profiling of OC tumor and microenvironment during disease progression, guiding the development of immunotherapies for OC treatment, especially for recurrent disease.

Keywords:  Cancer; Immunology; Therapy

DOI:  https://doi.org/10.1016/j.isci.2023.107952
bioRxiv. 2023 Sep 30. pii: 2023.09.30.560315. [Epub ahead of print]

Forward genetic screens identify mechanisms of resistance to small molecule lactate dehydrogenase inhibitors.

Anderson R Frank, Florentina Vandiver, David G McFadden.

Altered metabolism is a hallmark of cancer; however, it has been difficult to specifically target metabolism in cancer for therapeutic benefit. Cancers with genetically defined defects in metabolic enzymes constitute a subset of cancers where targeting metabolism is potentially accessible. Hürthle cell carcinoma of the thyroid (HTC) tumors frequently harbor deleterious mitochondrial DNA (mtDNA) mutations in subunits of complex I of the mitochondrial electron transport chain (ETC). Previous work has shown that HTC models with deleterious mtDNA mutations exhibit mitochondrial ETC defects that expose lactate dehydrogenase (LDH) as a therapeutic vulnerability. Here, we performed forward genetic screens to identify mechanisms of resistance to small molecule LDH inhibitors. We identified two distinct mechanisms of resistance: upregulation of an LDH isoform and a compound-specific resistance mutation. Using these tools, we demonstrate that the anti-cancer activity of LDH inhibitors in cell line and xenograft models of complex I-mutant HTC is through on-target LDH inhibition.

DOI: https://doi.org/10.1101/2023.09.30.560315
Cancers (Basel). 2023 Sep 29. pii: 4795. [Epub ahead of print]15(19):

Near-Infrared Imaging of Colonic Adenomas In Vivo Using Orthotopic Human Organoids for Early Cancer Detection.

Xiaoli Wu, Chun-Wei Chen, Sangeeta Jaiswal, Tse-Shao Chang, Ruoliu Zhang, Michael K Dame, Yuting Duan, Hui Jiang, Jason R Spence, Sen-Yung Hsieh, Thomas D Wang.

  Colorectal cancer is a leading cause of cancer-related morbidity and mortality worldwide. Premalignant lesions that are flat and subtle in morphology are often missed in conventional colonoscopies. Patient-derived adenoma colonoids with high and low cMet expression and normal colonoids were implanted orthotopically in the colon of immunocompromised mice to serve as a preclinical model system. A peptide specific for cMet was labeled with IRDye800, a near-infrared (NIR) fluorophore. This peptide was administered intravenously, and in vivo imaging was performed using a small animal fluorescence endoscope. Quantified intensities showed a peak target-to-background ratio at ~1 h after intravenous peptide injection, and the signal cleared by ~24 h. The peptide was stable in serum with a half-life of 3.6 h. Co-staining of adenoma and normal colonoids showed a high correlation between peptide and anti-cMet antibody. A human-specific cytokeratin stain verified the presence of human tissues implanted among surrounding normal mouse colonic mucosa. Peptide biodistribution was consistent with rapid renal clearance. No signs of acute toxicity were found on either animal necropsy or serum hematology and chemistries. Human colonoids provide a clinically relevant preclinical model to evaluate the specific uptake of a NIR peptide to detect premalignant colonic lesions in vivo.

Keywords:  cMet; cancer; colonoid; early detection; fluorescence; imaging; peptide

DOI:  https://doi.org/10.3390/cancers15194795
Langenbecks Arch Surg. 2023 Oct 10. 408(1): 392

Use of patient-derived explants as a preclinical model for precision medicine in colorectal cancer: A scoping review.

Milton Mui, Molly Clark, Tamara M S H Vu, Nicholas Clemons, Frédéric Hollande, Sara Roth, Robert Ramsay, Michael Michael, Alexander G Heriot, Joseph C H Kong.

   PURPOSE: Whilst the treatment paradigm for colorectal cancer has evolved significantly over time, there is still a lack of reliable biomarkers of treatment response. Treatment decisions are based on high-risk features such as advanced TNM stage and histology. The role of the tumour microenvironment, which can influence tumour progression and treatment response, has generated considerable interest. Patient-derived explant cultures allow preservation of native tissue architecture and tumour microenvironment. The aim of the scoping review is to evaluate the utility of patient-derived explant cultures as a preclinical model in colorectal cancer.
METHODS: A search was conducted using Ovid MEDLINE, EMBASE, Web of Science, and Cochrane databases from start of database records to September 1, 2022. We included all peer-reviewed human studies in English language which used patient-derived explants as a preclinical model in primary colorectal cancer. Eligible studies were grouped into the following categories: assessing model feasibility; exploring tumour microenvironment; assessing ex vivo drug responses; discovering and validating biomarkers.
RESULTS: A total of 60 studies were eligible. Fourteen studies demonstrated feasibility of using patient-derived explants as a preclinical model. Ten studies explored the tumour microenvironment. Thirty-eight studies assessed ex vivo drug responses of chemotherapy agents and targeted therapies. Twenty-four studies identified potential biomarkers of treatment response.
CONCLUSIONS: Given the preservation of tumour microenvironment and tumour heterogeneity, patient-derived explants has the potential to identify reliable biomarkers, treatment resistance mechanisms, and novel therapeutic agents. Further validation studies are required to characterise, refine and standardise this preclinical model before it can become a part of precision medicine in colorectal cancer.

Keywords:  Colorectal cancer; Patient-derived explants; Precision medicine; Tumour microenvironment

DOI:  https://doi.org/10.1007/s00423-023-03133-7
Sci Rep. 2023 10 10. 13(1): 17066

Quantifying intracellular glucose levels when yeast is grown in glucose media.

Xiang Li, Matthias Heinemann.

In Saccharomyces cerevisiae, intracellular glucose levels impact glucose transport and regulate carbon metabolism via various glucose sensors. To investigate mechanisms of glucose sensing, it is essential to know the intracellular glucose concentrations. Measuring intracellular glucose concentrations, however, is challenging when cells are grown on glucose, as glucose in the water phase around cells or stuck to the cell surface can be carried over during cell sampling and in the following attributed to intracellular glucose, resulting in an overestimation of intracellular glucose concentrations. Using lactose as a carryover marker in the growth medium, we found that glucose carryover originates from both the water phase and from sticking to the cell surface. Using a hexokinase null strain to estimate the glucose carryover from the cell surface, we found that glucose stuck on the cell surface only contributes a minor fraction of the carryover. To correct the glucose carryover, we revisited L-glucose as a carryover marker. Here, we found that L-glucose slowly enters cells. Thus, we added L-glucose to yeast cultures growing on uniformly 13C-labeled D-glucose only shortly before sampling. Using GC-MS to distinguish between the two differently labeled sugars and subtracting the carryover effect, we determined the intracellular glucose concentrations among two yeast strains with distinct kinetics of glucose transport to be at 0.89 mM in the wild-type strain and around 0.24 mM in a mutant with compromised glucose uptake. Together, our study provides insight into the origin of the glucose carryover effect and suggests that L-glucose added to the culture shortly before sampling is a possible method that yet has limitations with regard to measurement accuracy.

DOI: https://doi.org/10.1038/s41598-023-43602-z