Cancer metabolism: facts, fantasy, and fiction

Ethyl p-methoxycinnamate inhibits tumor growth by suppressing of fatty acid synthesis and depleting ATP

Cancer cells reprogram their energy metabolism pathways, but the mechanisms that enable them to meet their energy demands remain poorly understood. This study investigates the anticancer effects of ethyl p-methoxycinnamate (EMC) in Ehrlich ascites tumor cells (EATCs) and reveals that de novo fatty acid synthesis, rather than glycolysis, plays a pivotal role in sustaining energy homeostasis in cancer cells. EMC significantly reduced ATP levels despite enhancing glycolytic activity. It suppressed the expression of key enzymes involved in de novo fatty acid synthesis, including Acly, Acc1, and Fasn, resulting in decreased intracellular triglyceride (TG) levels. The addition of exogenous palmitic acid reversed EMC-induced ATP depletion and mitigated its anti-proliferative effects. Mechanistically, the ATP reduction caused by EMC was associated with inhibition of the c-Myc/SREBP1 pathway and arrest of the G1/S cell cycle transition. These findings demonstrate that EMC inhibits EATC proliferation by reducing ATP levels via suppression of de novo fatty acid synthesis. This study highlights the critical role of de novo fatty acid synthesis, rather than glycolysis, in maintaining energy homeostasis in cancer cells and provides novel insights into targeting cancer metabolism.

The Warburg hypothesis and the emergence of the mitochondrial metabolic theory of cancer

Otto Warburg originally proposed that cancer arose from a two-step process. The first step involved a chronic insufficiency of mitochondrial oxidative phosphorylation (OxPhos), while the second step involved a protracted compensatory energy synthesis through lactic acid fermentation. His extensive findings showed that oxygen consumption was lower while lactate production was higher in cancerous tissues than in non-cancerous tissues. Warburg considered both oxygen consumption and extracellular lactate as accurate markers for ATP production through OxPhos and glycolysis, respectively. Warburg's hypothesis was challenged from findings showing that oxygen consumption remained high in some cancer cells despite the elevated production of lactate suggesting that OxPhos was largely unimpaired. New information indicates that neither oxygen consumption nor lactate production are accurate surrogates for quantification of ATP production in cancer cells. Warburg also did not know that a significant amount of ATP could come from glutamine-driven mitochondrial substrate level phosphorylation in the glutaminolysis pathway with succinate produced as end product, thus confounding the linkage of oxygen consumption to the origin of ATP production within mitochondria. Moreover, new information shows that cytoplasmic lipid droplets and elevated aerobic lactic acid fermentation are both biomarkers for OxPhos insufficiency. Warburg's original hypothesis can now be linked to a more complete understanding of how OxPhos insufficiency underlies dysregulated cancer cell growth. These findings can also address several questionable assumptions regarding the origin of cancer thus allowing the field to advance with more effective therapeutic strategies for a less toxic metabolic management and prevention of cancer.

Phosphorylation of POU3F3 Mediated Nuclear Translocation Promotes Proliferation in Non-Small Cell Lung Cancer through Accelerating ATP5PF Transcription and ATP Production

Targeting oxidative phosphorylation (OXPHOS) through inhibiting the electron transport chain (ETC) has shown promising pre-clinical efficacy in cancer therapy. Although aerobic glycolysis is a hallmark of cancer, emerging evidence suggest OXPHOS is frequently enhanced, providing metabolic advantages for cell proliferation, metastasis, and drug resistance in a variety of aggressive cancer types including non-small cell lung cancer (NSCLC), yet the underlying molecular mechanisms remain elusive. Here it is reported that POU-domain containing family protein POU3F3 is translocated into the nuclei of NSCLC cell lines harboring mutant RAS, where it activates transcription of ATP5PF, an essential component of mitochondrial ATP synthase and consequent ATP production, leading to enhanced NSCLC proliferation and migration. Moreover, it is further found out that ERK1 phosphorylates POU3F3 at the S393 site in the cytoplasm and promotes the nuclear translocation of POU3F3 via receptor importin β1 in RAS mutant NSCLC cells. Mechanistically, RNA sequencing analysis combined with chromatin immunoprecipitation (ChIP) assay revealed that POU3F3 binds to the promoter of ATP5PF, leading to enhanced ATP5PF transcription and ATP production. Together, this study uncovers a novel RAS-POU3F3-ATP5PF axis in facilitating NSCLC progression, providing a new perspective on the understanding of molecular mechanisms for NSCLC progression.

Intranuclear TCA and mitochondrial overload: The nascent sprout of tumors metabolism

Abnormal glucose metabolism in tumors is a well-known form of metabolic reprogramming in tumor cells, the most representative of which, the Warburg effect, has been widely studied and discussed since its discovery. However, contradictions in a large number of studies and suboptimal efficacy of drugs targeting glycolysis have prompted us to further deepen our understanding of glucose metabolism in tumors. Here, we review recent studies on mitochondrial overload, nuclear localization of metabolizing enzymes, and intranuclear TCA (nTCA) in the context of the anomalies produced by inhibition of the Warburg effect. We provide plausible explanations for many of the contradictory points in the existing studies, including the causes of the Warburg effect. Furthermore, we provide a detailed prospective discussion of these studies in the context of these new findings, providing new ideas for the use of nTCA and mitochondrial overload in tumor therapy.

Redefining the role of hypoxia-inducible factors (HIFs) in oxygen homeostasis

Hypoxia-inducible factors (HIFs) are key regulators of intracellular oxygen homeostasis. The marked increase in HIFs activity in hypoxia as compared to normoxia, together with their transcriptional control of primary metabolic pathways, motivated the widespread view of HIFs as responsible for the cell's metabolic adaptation to hypoxic stress. In this work, we suggest that this prevailing model of HIFs regulation is misleading. We propose an alternative model focused on understanding the dynamics of HIFs' activity within its physiological context. Our model suggests that HIFs would not respond to but rather prevent the onset of hypoxic stress by regulating the traffic of electrons between catabolic substrates and oxygen. The explanatory power of our approach is patent in its interpretation of the Warburg effect, the tendency of tumor cells to favor anaerobic metabolism over respiration, even in fully aerobic conditions. This puzzling behavior is currently considered as an anomalous metabolic deviation. Our model predicts the Warburg effect as the expected homeostatic response of tumor cells to the abnormal increase in metabolic demand that characterizes malignant phenotypes. This alternative perspective prompts a redefinition of HIFs' function and underscores the need to explicitly consider the cell's metabolic activity in understanding its responses to changes in oxygen availability.

Microbes, macrophages, and melanin: a unifying theory of disease as exemplified by cancer

It is widely accepted that cancer mostly arises from random spontaneous mutations triggered by environmental factors. Our theory challenges the idea of the random somatic mutation theory (SMT). The SMT does not fit well with Charles Darwin's theory of evolution in that the same relatively few mutations would occur so frequently and that these mutations would lead to death rather than survival of the fittest. However, it would fit well under the theory of evolution, if we were to look at it from the vantage point of pathogens and their supporting microbial communities colonizing humans and mutating host cells for their own benefit, as it does give them an evolutionary advantage and they are capable of selecting genes to mutate and of inserting their own DNA or RNA into hosts. In this article, we provide evidence that tumors are actually complex microbial communities composed of various microorganisms living within biofilms encapsulated by a hard matrix; that these microorganisms are what cause the genetic mutations seen in cancer and control angiogenesis; that these pathogens spread by hiding in tumor cells and M2 or M2-like macrophages and other phagocytic immune cells and traveling inside them to distant sites camouflaged by platelets, which they also reprogram, and prepare the distant site for metastasis; that risk factors for cancer are sources of energy that pathogens are able to utilize; and that, in accordance with our previous unifying theory of disease, pathogens utilize melanin for energy for building and sustaining tumors and metastasis. We propose a paradigm shift in our understanding of what cancer is, and, thereby, a different trajectory for avenues of treatment and prevention.

Why and how citrate may sensitize malignant tumors to immunotherapy

Immunotherapy, either alone or in combination with chemotherapy, has demonstrated limited efficacy in a variety of solid cancers. Several factors contribute to explaining primary or secondary resistance. Among them, cancer cells, whose metabolism frequently relies on aerobic glycolysis, promote exhaustion of cytotoxic immune cells by diverting the glucose in the tumor microenvironment (TME) to their own profit, while secreting lactic acid that sustains the oxidative metabolism of immunosuppressive cells. Here, we propose to combine current treatment based on the use of immune checkpoint inhibitors (ICIs) with high doses of sodium citrate (SCT) because citrate inhibits cancer cell metabolism (by targeting both glycolysis and oxidative metabolism) and may active anti-tumor immune response. Indeed, as showed in preclinical studies, SCT reduces cancer cell growth, promoting cell death and chemotherapy effectiveness. Furthermore, since the plasma membrane citrate carrier pmCIC is mainly expressed in cancer cells and low or not expressed in immune and non-transformed cells, we argue that the inhibition of cancer cell metabolism by SCT may increase glucose availability in the TME, thus promoting functionality of anti-tumor immune cells. Concomitantly, the decrease in the amount of lactic acid in the TME may reduce the functionality of immunosuppressive cells. Preclinical studies have shown that SCT can enhance the anti-tumor immune response through an enhancement of T cell infiltration and activation, and a repolarization of macrophages towards a TAM1-like phenotype. Therefore, this simple and cheap strategy may have a major impact to increase the efficacy of current immunotherapies in human solid tumors and we encourage testing it in clinical trials.

Energy Metabolism Behavior and Response to Microenvironmental Factors of the Experimental Cancer Cell Models Differ from that of Actual Human Tumors

Analysis of the biochemical differences in the energy metabolism among bi-dimensional (2D) and tri-dimensional (3D) cultured cancer cell models and actual human tumors was undertaken. In 2D cancer cells, the oxidative phosphorylation (OxPhos) fluxes range is 2.5-19 nmol O2/min/mg cellular protein. Hypoxia drastically decreased OxPhos flux by 2-3 times in 2D models, similar to what occurs in mature multicellular tumor spheroids (MCTS), a representative 3D cancer cell model. However, mitochondrial protein contents and enzyme activities were significantly different between both models. Moreover, glycolytic fluxes were also significantly different between 2D and MCTS. The glycolytic flux range in 2D models is 1-34 nmol lactate/min/mg cellular protein, whereas in MCTS the range of glycolysis fluxes is 60-80 nmol lactate/min/mg cellular. In addition, sensitivity to anticancer canonical and metabolic drugs was greater in MCTS than in 2D. Actual solid human tumor samples show lower (1.6-4.5 times) OxPhos fluxes compared to normoxic 2D cancer cell cultures. These observations indicate that tridimensional organization provides a unique microenvironment affecting tumor physiology, which has not been so far faithfully reproduced by the 2D environment. Thus, the analysis of the resemblances and differences among cancer cell models undertaken in the present study raises caution on the interpretation of results derived from 2D cultured cancer cells when they are extended to clinical settings. It also raises awareness about detecting which biological and environmental factors are missing in 2D and 3D cancer cell models to be able to reproduce the actual human tumor behavior.

Unlocking the Heterogeneity in Acute Leukaemia: Dissection of Clonal Architecture and Metabolic Properties for Clinical Interventions

Genetic studies of haematological cancers have pointed out the heterogeneity of leukaemia in its different subpopulations, with distinct mutations and characteristics, impacting the treatment response. Next-generation sequencing (NGS) and genome-wide analyses, as well as single-cell technologies, have offered unprecedented insights into the clonal heterogeneity within the same tumour. A key component of this heterogeneity that remains unexplored is the intracellular metabolome, a dynamic network that determines cell functions, signalling, epigenome regulation, immunity and inflammation. Understanding the metabolic diversities among cancer cells and their surrounding environments is therefore essential in unravelling the complexities of leukaemia and improving therapeutic strategies. Here, we describe the currently available methodologies and approaches to addressing the dynamic heterogeneity of leukaemia progression. In the second section, we focus on metabolic leukaemic vulnerabilities in acute myeloid leukaemia (AML) and acute lymphoblastic leukaemia (ALL). Lastly, we provide a comprehensive overview of the most interesting clinical trials designed to target these metabolic dependencies, highlighting their potential to advance therapeutic strategies in leukaemia treatment. The integration of multi-omics data for cancer identification with the metabolic states of tumour cells will enable a comprehensive "micro-to-macro" approach for the refinement of clinical practices and delivery of personalised therapies.

Enhancing lobaplatin sensitivity in lung adenocarcinoma through inhibiting LDHA-targeted metabolic pathways

BACKGROUND AND OBJECTIVE

Lung adenocarcinoma (LUAD), a subtype of non-small cell lung cancer (NSCLC), is associated with high incidence and mortality rates. Effective treatment options are limited due to the frequent development of multidrug resistance, making it crucial to identify new therapeutic targets and sensitizing agents. This study investigates the role of Lactate dehydrogenase A (LDHA) in enhancing the chemotherapy sensitivity of Lobaplatin (LBP) in LUAD.

METHODS

Bioinformatics analyses were performed using data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) to assess LDHA expression in LUAD tissues. LUAD cell lines A549 and NCL-H1975 were treated with siRNA targeting LDHA and the small molecule inhibitor Oxamate. We measured changes in lactate production, ATP levels, NAD+ and pyruvate levels, and assessed cell viability. The chemotherapy sensitivity to Lobaplatin was evaluated, and key signaling pathways related to chemotherapy resistance were analyzed.

RESULTS

The inhibition of LDHA resulted in a significant reduction in lactate production and ATP levels, along with an increase in NAD+ and pyruvate levels. These metabolic alterations led to decreased cell viability and enhanced sensitivity to Lobaplatin. The study identified the PI3K/AKT signaling pathway as a critical mediator of this enhanced sensitivity, with reduced phosphorylation of AKT observed upon LDHA inhibition. Furthermore, the combination of LDHA inhibition and Lobaplatin treatment demonstrated a synergistic effect, significantly inhibiting tumor growth and highlighting the potential of LDHA as a therapeutic target to overcome drug resistance in LUAD.

CONCLUSION

Targeting LDHA and disrupting lactate metabolism and its signaling pathways can effectively enhance the sensitivity of LUAD to Lobaplatin, providing a promising approach to overcoming multidrug resistance. These findings offer valuable insights into developing new treatment strategies for lung adenocarcinoma, emphasizing the role of metabolic pathways in cancer therapy.

Mitochondrial proteome analysis reveals that an augmented cytochrome c oxidase assembly and activity potentiates respiratory capacity in sarcoma

Mitochondrial oxidative phosphorylation (OXPHOS) is an obligatory process in sarcoma. Despite that, the metabolic programming of sarcoma mitochondria is still unknown. To obtain a comprehensive metabolic insight of mitochondria, we developed a mouse fibrosarcoma model by injecting 3-methylcholanthrene and compared mitochondrial proteomes between sarcoma and its contralateral normal muscle using mass spectrometry. Our study identified ∼449 proteins listed in the SwissProt databases, and all the data sets are available via ProteomeXchange with the identifier PXD044903. In sarcoma, 49 mitochondrial proteins were found differentially expressed, including 36 proteins up-regulated and 13 proteins down-regulated, with the significance of p-value <0.05 and the log2[fold change] > 1 and < -1 as compared to normal muscle. Our data revealed that various anaplerotic reactions actively replenish the TCA cycle in sarcoma. The comparative expression profile and Western blotting analysis of OXPHOS subunits showed that complex-IV subunits, MT-CO3 and COX6A1, were significantly up-regulated in sarcoma vs. normal muscle. Further, biochemical and physiological assays confirmed enhanced complex-IV specific enzymatic and supercomplex activities with a concomitant increase of oxygen consumption rate in sarcoma mitochondria compared to normal muscle. Validation with human post-operative sarcoma tissues also confirms an increased MT-CO3 expression compared to normal tissue counterparts. Thus, our data comprehensively analyses the mitochondrial proteome and identifies augmented complex-IV assembly and activity in sarcoma.

The role of mitochondria in tumor metastasis and advances in mitochondria-targeted cancer therapy

Mitochondria are central actors in diverse physiological phenomena ranging from energy metabolism to stress signaling and immune modulation. Accumulating scientific evidence points to the critical involvement of specific mitochondrial-associated events, including mitochondrial quality control, intercellular mitochondrial transfer, and mitochondrial genetics, in potentiating the metastatic cascade of neoplastic cells. Furthermore, numerous recent studies have consistently emphasized the highly significant role mitochondria play in coordinating the regulation of tumor-infiltrating immune cells and immunotherapeutic interventions. This review provides a comprehensive and rigorous scholarly investigation of this subject matter, exploring the intricate mechanisms by which mitochondria contribute to tumor metastasis and examining the progress of mitochondria-targeted cancer therapies.

Metabolic Adaptations in Cancer and the Host Using Drosophila Models and Advanced Tools

Cancer is a multifactorial process involving genetic, epigenetic, physiological, and metabolic changes. The ability of tumours to regulate new reactive pathways is essential for their survival. A key aspect of this involves the decision-making process of cancer cells as they balance the exploitation of surrounding and distant tissues for their own benefit while avoiding the rapid destruction of the host. Nutrition plays a central role in these processes but is inherently limited. Understanding how tumour cells interact with non-tumoural tissues to acquire nutrients is crucial. In this review, we emphasise the utility of Drosophila melanogaster as a model organism for dissecting the complex oncogenic networks underlying these interactions. By studying various levels-from individual tumour cells to systemic markers-we can gain new insights into how cancer adapts and thrives. Moreover, developing innovative technologies, such as high-throughput methods and metabolic interventions, enhances our ability to explore how tumours adapt to different conditions. These technological advances allow us to explore tumour adaptations and open new opportunities for potential therapeutic strategies.

NSUN4-mediated m5C modification of circERI3 promotes lung cancer development by altering mitochondrial energy metabolism

As a highly important methylation modification, the 5-methyladenosine (m5C) modification can profoundly affect RNAs by regulating their transcription, structure and stability. With the continuous development of high-throughput technology, differentially expressed circular RNAs (circRNAs) have been increasingly discovered, and circRNAs play unique roles in tumorigenesis and development. However, the regulatory mechanism of the m5C modification of circRNAs has not yet been revealed. In this study, circERI3, which is highly expressed in lung cancer tissue and significantly correlated with the clinical progression of lung cancer, was initially identified through differential expression profiling of circRNAs. A combined m5C microarray analysis revealed that circERI3 contains the m5C modification and that the NSUN4-mediated m5C modification of circERI3 can increase its nuclear export. The important function of circERI3 in promoting lung cancer progression in vitro and in vivo was clarified. Moreover, we elucidated the novel mechanism by which circERI3 targets DNA binding protein 1 (DDB1), regulates its ubiquitination, enhances its stability, and in turn promotes the transcription of peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) through DDB1 to affect mitochondrial function and energy metabolism, which ultimately promotes the development of lung cancer. This study not only revealed the reasons for the abnormal distribution of circERI3 in lung cancer tissues from the perspective of methylation and clarified the important role of circERI3 in lung cancer progression but also described a novel mechanism by which circERI3 promotes lung cancer development through mitochondrial energy metabolism, providing new insights for the study of circRNAs in lung cancer.

The Warburg Effect: Is it Always an Enemy?

The Warburg effect, also known as 'aerobic' glycolysis, describes the preference of cancer cells to favor glycolysis over oxidative phosphorylation for energy (adenosine triphosphate-ATP) production, despite having high amounts of oxygen and fully active mitochondria, a phenomenon first identified by Otto Warburg. This metabolic pathway is traditionally viewed as a hallmark of cancer, supporting rapid growth and proliferation by supplying energy and biosynthetic precursors. However, emerging research indicates that the Warburg effect is not just a strategy for cancer cells to proliferate at higher rates compared to normal cells; thus, it should not be considered an 'enemy' since it also plays complex roles in normal cellular functions and/or under stress conditions, prompting a reconsideration of its purely detrimental characterization. Moreover, this review highlights that distinguishing glycolysis as 'aerobic' and 'anaerobic' should not exist, as lactate is likely the final product of glycolysis, regardless of the presence of oxygen. Finally, this review explores the nuanced contributions of the Warburg effect beyond oncology, including its regulatory roles in various cellular environments and the potential effects on systemic physiological processes. By expanding our understanding of these mechanisms, we can uncover novel therapeutic strategies that target metabolic reprogramming, offering new avenues for treating cancer and other diseases characterized by metabolic dysregulation. This comprehensive reevaluation not only challenges traditional views but also enhances our understanding of cellular metabolism's adaptability and its implications in health and disease.

Nuclear TOP1MT Confers Cisplatin Resistance via Pseudogene in HNSCC

Cisplatin resistance is one of the major causes of treatment failure in head and neck squamous cell carcinoma (HNSCC). There is an urgent need to uncover the underlying mechanism for developing effective treatment strategies. A quantitative proteomics assay was used to identify differential proteins in cisplatin-resistant cells. Mitochondrial topoisomerase I (TOP1MT) localization was determined using laser confocal microscopy and nucleocytoplasmic separation assay. Chromatin immunoprecipitation sequencing, dual-luciferase reporter assay, and RNA immunoprecipitation were used to identify the interaction between pseudogenes, miRNAs, and real genes. In vivo experiments verified the interaction between TOP1MT and pseudogenes on cisplatin resistance. TOP1MT was identified as a driving factor of cisplatin resistance in vitro, in vivo, and in HNSCC patients. Moreover, TOP1MT exceptionally translocated to the nucleus in cisplatin-resistant HNSCC cells in a signal peptide-dependent manner. Nuclear TOP1MT (nTOP1MT) transcriptionally regulated the mitochondrial functional pseudogene MTATP6P1, which bound to miR-137 and miR-491-5p as a competing endogenous RNA (ceRNA) and promoted the expression of MTATP6. An increase in MTATP6 enhanced mitochondrial oxidative phosphorylation (OXPHOS), which conferred cisplatin resistance in HNSCC. Our findings revealed that nTOP1MT transcriptionally activated MTAPT6P1 and increased MTATP6 expression via ceRNA, which facilitated OXPHOS and cisplatin resistance. These results provide novel insight for overcoming cisplatin resistance in HNSCC.

Oxidative phosphorylation related gene COA6 is a novel indicator for the prognosis and immune response in lung adenocarcinoma

Although the initial research focused on glycolysis, mitochondrial oxidative phosphorylation has become a major target of cancer cells. Cytochrome C oxidase assembly factor 6 (COA6) is a conserved assembly factor necessary for complex IV biogenesis. Nevertheless, the clinical predictive value of COA6, especially its correlation with immune cell infiltration in lung adenocarcinoma (LUAD), has not yet been elucidated. COA6 exhibited higher expression levels in LUAD cells and tumor tissues compared to normal tissues. Additionally, heightened COA6 expression was associated with reduced overall survival (OS) and advanced tumor stage. Apart from its role in mitochondrial respiratory processes, COA6 may be involved in the process of antigen binding, immunoglobulin receptor binding. Interestingly, we observed a positive correlation between COA6 expression and tumor mutational burden (TMB), as well as a significant association with decreased immune cell infiltration. COA6 was linked to resistance against gemcitabine and etoposide. We verified that COA6 was highly expressed in LUAD experimentally and cell proliferation was inhibited after COA6 knockdown. Thus, we conclude that the expression of COA6 was correlated with reduced immune cell infiltration. Additionally, COA6 functioned as a biomarker for drug sensitivity and the prognosis of lung adenocarcinoma.

Metabolic dependencies of acute myeloid leukemia stem cells

Acute myeloid leukemia (AML) is a heterogeneous hematologic malignancy primarily driven by an immature population of AML cells termed leukemia stem cells (LSCs) that are implicated in AML development, chemoresistance, and relapse. An emerging area of research in AML focuses on identifying and targeting the aberrant metabolism in LSCs. Dysregulated metabolism is involved in sustaining functional properties of LSCs, impeding myeloid differentiation, and evading programmed cell death, both in the process of leukemogenesis and in response to chemotherapy. This review discusses recent discoveries regarding the aberrant metabolic processes of AML LSCs that have begun to change the therapeutic landscape of AML.

Role of pyruvate kinase M2 in regulating sepsis (Review)

Glycolysis occurs in all living organisms as a form of energy supply. Pyruvate kinase M2 (PKM2) is one of the rate‑limiting enzymes in the glycolytic process. PKM2 is considered to serve an important role in several terminal diseases, including sepsis. However, to the best of our knowledge, the specific mechanistic role of PKM2 in sepsis remains to be systematically summarised. Therefore, the present review aims to summarise the roles of PKM2 in sepsis progression. In addition, potential treatment strategies for patients with sepsis are discussed. The present review hopes to lay the groundwork for studying the role of PKM2 and developing therapeutic strategies against metabolic disorders that occur during sepsis.

Divergent iron regulatory states contribute to heterogeneity in breast cancer aggressiveness

Contact with dense collagen I (Col1) can induce collective invasion of triple negative breast cancer (TNBC) cells and transcriptional signatures linked to poor patient prognosis. However, this response is heterogeneous and not well understood. Using phenotype-guided sequencing analysis of invasive vs. noninvasive subpopulations, we show that these two phenotypes represent opposite sides of the iron response protein 1 (IRP1)-mediated response to cytoplasmic labile iron pool (cLIP) levels. Invasive cells upregulate iron uptake and utilization machinery characteristic of a low cLIP response, which includes contractility regulating genes that drive migration. Non-invasive cells upregulate iron sequestration machinery characteristic of a high cLIP response, which is accompanied by upregulation of actin sequestration genes. These divergent IRP1 responses result from Col1-induced transient expression of heme oxygenase I (HO-1), which cleaves heme and releases iron. These findings lend insight into the emerging theory that heme and iron fluxes regulate TNBC aggressiveness.

Structure-activity relationships study of N-ethylene glycol-comprising alkyl heterocyclic carboxamides against A549 lung cancer cells

Aim: Certain cancer cells depend on oxidative phosphorylation for survival; thus, inhibiting this process may be a promising treatment strategy. This study explored the structure-activity relationships of the mitochondrial inhibitor N-ethylene glycol-comprising alkyl thiophene-3-carboxamide 3.Methods & results: We synthesized and evaluated 13 analogs (5a-m) with different ethylene glycol units, heterocycles and connecting groups for their growth-inhibitory effects on A549 non-small cell lung cancer cells. We found that increasing the number of ethylene glycol units significantly enhanced inhibitory activity. Some analogs activated adenosine monophosphate-activated protein kinase, similar to 3. Notably, analog 5e, which contains tetraethylene glycol units, significantly inhibited tumor growth in vivo.Conclusion: Analog 5 may be a potential therapeutic agent for non-small cell lung cancer treatment.

The multifaceted role of quercetin derived from its mitochondrial mechanism

Quercetin is a flavonoid with promising therapeutic applications; nonetheless, the phenotype exerted in some diseases is contradictory. For instance, anticancer properties may be explained by a cytotoxic mechanism, whereas antioxidant-related neuroprotection is a pro-survival process. According to the available literature, quercetin exerts a redox interaction with the electron transport chain (ETC) in the mitochondrion, affecting its membrane potential. It also affects ATP generation by oxidative phosphorylation, where ATP deprivation could partly explain its cytotoxic effect. Moreover, quercetin may support the generation of free radicals through redox reactions, causing a prooxidant effect. The nutrimental stress and prooxidant effect induced by quercetin might promote pro-survival properties such as antioxidant processes. Thus, in this review, we discuss the evidence supporting that quercetin redox interaction with the ETC could explain its beneficial and toxic properties.

The bioenergetic landscape of cancer

BACKGROUND

Bioenergetic remodeling of core energy metabolism is essential to the initiation, survival, and progression of cancer cells through exergonic supply of adenosine triphosphate (ATP) and metabolic intermediates, as well as control of redox homeostasis. Mitochondria are evolutionarily conserved organelles that mediate cell survival by conferring energetic plasticity and adaptive potential. Mitochondrial ATP synthesis is coupled to the oxidation of a variety of substrates generated through diverse metabolic pathways. As such, inhibition of the mitochondrial bioenergetic system by restricting metabolite availability, direct inhibition of the respiratory Complexes, altering organelle structure, or coupling efficiency may restrict carcinogenic potential and cancer progression.

SCOPE OF REVIEW

Here, we review the role of bioenergetics as the principal conductor of energetic functions and carcinogenesis while highlighting the therapeutic potential of targeting mitochondrial functions.

MAJOR CONCLUSIONS

Mitochondrial bioenergetics significantly contribute to cancer initiation and survival. As a result, therapies designed to limit oxidative efficiency may reduce tumor burden and enhance the efficacy of currently available antineoplastic agents.

7-amino carboxycoumarin 2 inhibits lactate induced epithelial-to-mesenchymal transition via MPC1 in oral and breast cancer cells

Lactate is an oncometabolite that play important role in tumor aggressiveness. Lactate from the tumor microenvironment (TME) is taken up by cancer cells as an energy resource via mitochondrial oxidative phosphorylation (or OXPHOS). In the present study, by using an online meta-analysis tool we demonstrated that in oral squamous cancer cells (OSCCs) glycolytic and OXPHOS governing genes are overexpressed, like in breast cancer. For experimental demonstration, we treated the OSCC cell line (SCC4) and breast cancer cells (MDA-MB-231) with sodium L-lactate and analyzed its effects on changes in EMT and migration. For the therapeutic intervention of lactate metabolism, we used AZD3965 (an MCT1 inhibitor), and 7ACC2 (an MPC inhibitor). Like breast cancer, oral cancer tissues showed increased transcripts of 12 genes that were previously shown to be associated with glycolysis and OXPHOS. We experimentally demonstrated that L-lactate treatment induced mesenchymal markers and migration of cancer cells, which was significantly neutralized by MPC inhibitor that is, 7ACC2. Such an effect on EMT status was not observed with AZD3965. Furthermore, we showed that lactate treatment increases the MPC1 expression in both cancer cells, and this might be the reason why cancer cells in the high lactate environment are more sensitive to 7ACC2. Overall, our present findings demonstrate that extracellular lactate positively regulates the MPC1 protein expression in cancer cells, thereby putting forward the notion of using 7ACC2 as a potential therapeutic alternative to inhibit malignant oxidative cancers. Future preclinical studies are warranted to validate the present findings.

Using Gaussian accelerated molecular dynamics combined with Markov state models to explore the mechanism of action of new oral inhibitors on Complex I

In this study, our focus was on investigating H-1,2,3-triazole derivative HP661 as a novel and highly efficient oral OXPHOS inhibitor, with its molecular-level inhibitory mechanism not yet fully understood. We selected the ND1, NDUFS2, and NDUFS7 subunits of Mitochondrial Complex I as the receptor proteins and established three systems for comparative analysis: protein-IACS-010759, protein-lead compound 10, and protein-HP661. Through extensive analysis involving 500 ns Gaussian molecular dynamics simulations, we gained insights into these systems. Additionally, we constructed a Markov State Models to examine changes in secondary structures during the motion processes. The research findings suggest that the inhibitor HP661 enhances the extensibility and hydrophilicity of the receptor protein. Furthermore, HP661 induces the unwinding of the α-helical structure in the region of residues 726-730. Notably, key roles were identified for Met37, Phe53, and Pro212 in the binding of various inhibitors. In conclusion, we delved into the potential molecular mechanisms of triazole derivative HP661 in inhibiting Complex I. These research outcomes provide crucial information for a deeper understanding of the mechanisms underlying OXPHOS inhibition, offering valuable theoretical support for drug development and disease treatment design.

Immunometabolism unveiled: Pioneering breakthroughs in cancer therapeutics

The field of immunometabolism cannot be considered 'emerging' anymore; it is at the moment one of the most active and rapidly evolving areas of biomedical research. Its hottest zone is cancer immunometabolism. This is partly due to the clinical application of immunotherapy, with either antibodies (checkpoint blockade) or cellular therapies (e.g., CAR-T cells). In addition, the proliferating tumor cells create a nutrient-deprived microenvironment that impairs the metabolic fitness and functionality of infiltrating immune cells such as T cells, NK cells, and macrophages. The key concepts are bidirectional metabolic signaling, plus the conviction that a better understanding of these processes will improve current immunotherapies, and foster new tools and targets for treatment. This collection of reviews will address various exciting aspects from junior and established scientists in the field.

Glycolytic enzymes in non-glycolytic web: functional analysis of the key players

To survive in the tumour microenvironment, cancer cells undergo rapid metabolic reprograming and adaptability. One of the key characteristics of cancer is increased glycolytic selectivity and decreased oxidative phosphorylation (OXPHOS). Apart from ATP synthesis, glycolysis is also responsible for NADH regeneration and macromolecular biosynthesis, such as amino acid biosynthesis and nucleotide biosynthesis. This allows cancer cells to survive and proliferate even in low-nutrient and oxygen conditions, making glycolytic enzymes a promising target for various anti-cancer agents. Oncogenic activation is also caused by the uncontrolled production and activity of glycolytic enzymes. Nevertheless, in addition to conventional glycolytic processes, some glycolytic enzymes are involved in non-canonical functions such as transcriptional regulation, autophagy, epigenetic changes, inflammation, various signaling cascades, redox regulation, oxidative stress, obesity and fatty acid metabolism, diabetes and neurodegenerative disorders, and hypoxia. The mechanisms underlying the non-canonical glycolytic enzyme activities are still not comprehensive. This review summarizes the current findings on the mechanisms fundamental to the non-glycolytic actions of glycolytic enzymes and their intermediates in maintaining the tumor microenvironment.

Relevance of Cardiovascular Exercise in Cancer and Cancer Therapy-Related Cardiac Dysfunction

PURPOSE OF THE REVIEW

Cancer therapy-related cardiac dysfunction (CTRCD) has been identified as a threat to overall and cancer-related survival. Although aerobic exercise training (AET) has been shown to improve cardiorespiratory fitness (CRF), the relationship between specific exercise regimens and cancer survival, heart failure development, and reduction of CTRCD is unclear. In this review, we discuss the impact of AET on molecular pathways and the current literature of sports in the field of cardio-oncology.

RECENT FINDINGS

Cardio-oncological exercise trials have focused on variations of AET intensity by using moderate continuous and high intensity interval training, which are applicable, safe, and effective approaches to improve CRF. AET increases CRF, reduces cardiovascular morbidity and heart failure hospitalization and should thus be implemented as an adjunct to standard cancer therapy, although its long-term effect on CTRCD remains unknown. Despite modulating diverse molecular pathways, it remains unknown which exercise regimen, including variations of AET duration and frequency, is most suited to facilitate peripheral and central adaptations to exercise and improve survival in cancer patients.

Should the standard model of cellular energy metabolism be reconsidered? Possible coupling between the pentose phosphate pathway, glycolysis and extra-mitochondrial oxidative phosphorylation

The process of cellular respiration occurs for energy production through catabolic reactions, generally with glucose as the first process step. In the present work, we introduce a novel concept for understanding this process, based on our conclusion that glucose metabolism is coupled to the pentose phosphate pathway (PPP) and extra-mitochondrial oxidative phosphorylation in a closed-loop process. According to the current standard model of glycolysis, glucose is first converted to glucose 6-phosphate (glucose 6-P) and then to fructose 6-phosphate, glyceraldehyde 3-phosphate and pyruvate, which then enters the Krebs cycle in the mitochondria. However, it is more likely that the pyruvate will be converted to lactate. In the PPP, glucose 6-P is branched off from glycolysis and used to produce NADPH and ribulose 5-phosphate (ribulose 5-P). Ribulose 5-P can be converted to fructose 6-P and glyceraldehyde 3-P. In our view, a circular process can take place in which the ribulose 5-P produced by the PPP enters the glycolysis pathway and is then retrogradely converted to glucose 6-P. This process is repeated several times until the complete degradation of glucose 6-P. The role of mitochondria in this process is to degrade lipids by beta-oxidation and produce acetyl-CoA; the function of producing ATP appears to be only secondary. This proposed new concept of cellular bioenergetics allows the resolution of some previously unresolved controversies related to cellular respiration and provides a deeper understanding of metabolic processes in the cell, including new insights into the Warburg effect.

Metabolomics at the tumor microenvironment interface: Decoding cellular conversations

Cancer heterogeneity remains a significant challenge for effective cancer treatments. Altered energetics is one of the hallmarks of cancer and influences tumor growth and drug resistance. Studies have shown that heterogeneity exists within the metabolic profile of tumors, and personalized-combination therapy with relevant metabolic interventions could improve patient response. Metabolomic studies are identifying novel biomarkers and therapeutic targets that have improved treatment response. The spatial location of elements in the tumor microenvironment are becoming increasingly important for understanding disease progression. The evolution of spatial metabolomics analysis now allows scientists to deeply understand how metabolite distribution contributes to cancer biology. Recently, these techniques have spatially resolved metabolite distribution to a subcellular level. It has been proposed that metabolite mapping could improve patient outcomes by improving precision medicine, enabling earlier diagnosis and intraoperatively identifying tumor margins. This review will discuss how altered metabolic pathways contribute to cancer progression and drug resistance and will explore the current capabilities of spatial metabolomics technologies and how these could be integrated into clinical practice to improve patient outcomes.

Targeting Mitochondria for Cancer Treatment

There is an increasing accumulation of data on the exceptional importance of mitochondria in the occurrence and treatment of cancer, and in all lines of evidence for such participation, there are both energetic and non-bioenergetic functional features of mitochondria. This analytical review examines three specific features of adaptive mitochondrial changes in several malignant tumors. The first feature is characteristic of solid tumors, whose cells are forced to rebuild their energetics due to the absence of oxygen, namely, to activate the fumarate reductase pathway instead of the traditional succinate oxidase pathway that exists in aerobic conditions. For such a restructuring, the presence of a low-potential quinone is necessary, which cannot ensure the conventional conversion of succinate into fumarate but rather enables the reverse reaction, that is, the conversion of fumarate into succinate. In this scenario, complex I becomes the only generator of energy in mitochondria. The second feature is the increased proliferation in aggressive tumors of the so-called mitochondrial (peripheral) benzodiazepine receptor, also called translocator protein (TSPO) residing in the outer mitochondrial membrane, the function of which in oncogenic transformation stays mysterious. The third feature of tumor cells is the enhanced retention of certain molecules, in particular mitochondrially directed cations similar to rhodamine 123, which allows for the selective accumulation of anticancer drugs in mitochondria. These three features of mitochondria can be targets for the development of an anti-cancer strategy.

A Comparison of In Vitro Studies between Cobalt(III) and Copper(II) Complexes with Thiosemicarbazone Ligands to Treat Triple Negative Breast Cancer

Metal complexes have gained significant attention as potential anti-cancer agents. The anti-cancer activity of [Co(phen)2(MeATSC)](NO3)3•1.5H2O•C2H5OH 1 (where phen = 1,10-phenanthroline and MeATSC = 9-anthraldehyde-N(4)-methylthiosemicarbazone) and [Cu(acetylethTSC)Cl]Cl•0.25C2H5OH 2 (where acetylethTSC = (E)-N-ethyl-2-[1-(thiazol-2-yl)ethylidene]hydrazinecarbothioamide) was investigated by analyzing DNA cleavage activity. The cytotoxic effect was analyzed using CCK-8 viability assay. The activities of caspase 3/7, 9, and 1, reactive oxygen species (ROS) production, cell cycle arrest, and mitochondrial function were further analyzed to study the cell death mechanisms. Complex 2 induced a significant increase in nicked DNA. The IC50 values of complex 1 were 17.59 μM and 61.26 μM in cancer and non-cancer cells, respectively. The IC50 values of complex 2 were 5.63 and 12.19 μM for cancer and non-cancer cells, respectively. Complex 1 induced an increase in ROS levels, mitochondrial dysfunction, and activated caspases 3/7, 9, and 1, which indicated the induction of intrinsic apoptotic pathway and pyroptosis. Complex 2 induced cell cycle arrest in the S phase, ROS generation, and caspase 3/7 activation. Thus, complex 1 induced cell death in the breast cancer cell line via activation of oxidative stress which induced apoptosis and pyroptosis while complex 2 induced cell cycle arrest through the induction of DNA cleavage.

The Warburg Effect Reinterpreted 100 yr on: A First-Principles Stoichiometric Analysis and Interpretation from the Perspective of ATP Metabolism in Cancer Cells

The Warburg Effect is a longstanding enigma in cancer biology. Despite the passage of 100 yr since its discovery, and the accumulation of a vast body of research on the subject, no convincing biochemical explanation has been given for the original observations of aerobic glycolysis in cancer cell metabolism. Here, we have worked out a first-principles quantitative analysis of the problem from the principles of stoichiometry and available electron balance. The results have been interpreted using Nath's unified theory of energy coupling and adenosine triphosphate (ATP) synthesis, and the original data of Warburg and colleagues have been analyzed from this new perspective. Use of the biomass yield based on ATP per unit substrate consumed, [Formula: see text], or the Nath-Warburg number, NaWa has been shown to excellently model the original data on the Warburg Effect with very small standard deviation values, and without employing additional fitted or adjustable parameters. Based on the results of the quantitative analysis, a novel conservative mechanism of synthesis, utilization, and recycling of ATP and other key metabolites (eg, lactate) is proposed. The mechanism offers fresh insights into metabolic symbiosis and coupling within and/or among proliferating cells. The fundamental understanding gained using our approach should help in catalyzing the development of more efficient metabolism-targeting anticancer drugs.

Durable Attenuation of Tumor pH-Platelet Linkage Reinstates Bioorthogonal Targeting of Residual Tumors Post-Debulking

There are circumstances where tumors can only be partially resected. Therefore, multimodality therapy targeting post-operative residuals is important. Here, we show that bioorthogonal click chemistry enables targeted delivery to heterogeneous tumors, but its utility against tumor post-debulking is ineffective due to platelet cloaks that shield tumor cells from bioorthogonal pairing. We further discover tumor-infiltrating platelet levels respond to local pH changes. Elucidating this pH-platelet linkage, we design an injectable hydrogel for resection cavity implantation that simultaneously azido-tags tumor cells and inhibit their catalysis to acidify surrounding milieu. Unlike transient buffering, tumor acidification blockade sustains pH normalization, leading to durable platelet reduction. This reinstates bioorthogonal targeting of dibenzyl cyclooctyne-modified nanoparticles, thereby enhancing photodynamic ablation of residuals while amplifying systemic antitumor immunity. Concurrently, platelet/pH normalization interrupts metastasis cascade from invasion to circulation to colonization. Overall, attenuating tumor pH-platelet linkage unlocks bioorthogonal chemistry as a potential option for adjuvant therapy after tumor debulking.

Tuberculosis and lung cancer: metabolic pathways play a key role

Despite the fact that some cases of tuberculosis (TB) are undiagnosed and untreated, it remains a serious global public health issue. In the diagnosis, treatment, and control of latent and active TB, there may be a lack of effectiveness. An understanding of metabolic pathways can be fundamental to treat latent TB infection and active TB disease. Rather than targeting Mycobacterium tuberculosis, the control strategies aim to strengthen host responses to infection and reduce chronic inflammation by effectively enhancing host resistance to infection. The pathogenesis and progression of TB are linked to several metabolites and metabolic pathways, and they are potential targets for host-directed therapies. Additionally, metabolic pathways can contribute to the progression of lung cancer in patients with latent or active TB. A comprehensive metabolic pathway analysis is conducted to highlight lung cancer development in latent and active TB. The current study aimed to emphasize the association between metabolic pathways of tumor development in patients with latent and active TB. Health control programs around the world are compromised by TB and lung cancer due to their special epidemiological and clinical characteristics. Therefore, presenting the importance of lung cancer progression through metabolic pathways occurring upon TB infection can open new doors to improving control of TB infection and active TB disease while stressing that further evaluations are required to uncover this correlation.

Oxygen and Iron Availability Shapes Metabolic Adaptations of Cancer Cells

The dynamic changes between glycolysis and oxidative phosphorylation (OXPHOS) for adenosine triphosphate (ATP) output, along with glucose, glutamine, and fatty acid utilization, etc., lead to the maintenance and selection of growth advantageous to tumor cell subgroups in an environment of iron starvation and hypoxia. Iron plays an important role in the three major biochemical reactions in nature: photosynthesis, nitrogen fixation, and oxidative respiration, which all require the participation of iron-sulfur proteins, such as ferredoxin, cytochrome b, and the complex I, II, III in the electron transport chain, respectively. Abnormal iron-sulfur cluster synthesis process or hypoxia will directly affect the function of mitochondrial electron transfer and mitochondrial OXPHOS. More research results have indicated that iron metabolism, oxygen availability and hypoxia-inducible factor mutually regulate the shift between glycolysis and OXPHOS. In this article, we make a perspective review to provide novel opinions of the regulation of glycolysis and OXPHOS in tumor cells.

Mitochondrial Proteins as Metabolic Biomarkers and Sites for Therapeutic Intervention in Primary and Metastatic Cancers

Accelerated aerobic glycolysis is one of the main metabolic alterations in cancer, associated with malignancy and tumor growth. Although glycolysis is one of the most studied properties of tumor cells, recent studies demonstrate that oxidative phosphorylation (OxPhos) is the main ATP provider for the growth and development of cancer. In this last regard, the levels of mRNA and protein of OxPhos enzymes and transporters (including glutaminolysis, acetate and ketone bodies catabolism, free fatty acid β-oxidation, Krebs Cycle, respiratory chain, phosphorylating system- ATP synthase, ATP/ADP translocator, Pi carrier) are altered in tumors and cancer cells in comparison to healthy tissues and organs, and non-cancer cells. Both energy metabolism pathways are tightly regulated by transcriptional factors, oncogenes, and tumor-suppressor genes, all of which dictate their protein levels depending on the micro-environmental conditions and the type of cancer cell, favoring cancer cell adaptation and growth. In the present review paper, variation in the mRNA and protein levels as well as in the enzyme/ transporter activities of the OxPhos machinery is analyzed. An integral omics approach to mitochondrial energy metabolism pathways may allow for identifying their use as suitable, reliable biomarkers for early detection of cancer development and metastasis, and for envisioned novel, alternative therapies.

Glycolysis Reprogramming in Idiopathic Pulmonary Fibrosis: Unveiling the Mystery of Lactate in the Lung

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive lung disease characterized by excessive deposition of fibrotic connective tissue in the lungs. Emerging evidence suggests that metabolic alterations, particularly glycolysis reprogramming, play a crucial role in the pathogenesis of IPF. Lactate, once considered a metabolic waste product, is now recognized as a signaling molecule involved in various cellular processes. In the context of IPF, lactate has been shown to promote fibroblast activation, myofibroblast differentiation, and extracellular matrix remodeling. Furthermore, lactate can modulate immune responses and contribute to the pro-inflammatory microenvironment observed in IPF. In addition, lactate has been implicated in the crosstalk between different cell types involved in IPF; it can influence cell-cell communication, cytokine production, and the activation of profibrotic signaling pathways. This review aims to summarize the current research progress on the role of glycolytic reprogramming and lactate in IPF and its potential implications to clarify the role of lactate in IPF and to provide a reference and direction for future research. In conclusion, elucidating the intricate interplay between lactate metabolism and fibrotic processes may lead to the development of innovative therapeutic strategies for IPF.

The Warburg effect: a signature of mitochondrial overload

A long-standing question in cancer biology has been why oxygenated tumors ferment the majority of glucose they consume to lactate rather than oxidizing it in their mitochondria, a phenomenon known as the 'Warburg effect.' An abundance of evidence shows not only that most cancer cells have fully functional mitochondria but also that mitochondrial activity is important to proliferation. It is therefore difficult to rationalize the metabolic benefit of cancer cells switching from respiration to fermentation. An emerging perspective is that rather than mitochondrial metabolism being suppressed in tumors, as is often suggested, mitochondrial activity increases to the level of saturation. As such, the Warburg effect becomes a signature of excess glucose being released as lactate due to mitochondrial overload.

LncRNA MAFG-AS1 is involved in human cancer progression

Long noncoding RNAs (lncRNAs) refer to a type of non-protein-coding transcript of more than 200 nucleotides. LncRNAs play fundamental roles in disease development and progression, and lncRNAs are dysregulated in many pathophysiological processes. Thus, lncRNAs may have potential value in clinical applications. The lncRNA, MAF BZIP Transcription Factor G (MAFG)-AS1, is dysregulated in several cancer, including breast cancer, lung cancer, liver cancer, bladder cancer, colorectal cancer, gastric cancer, esophagus cancer, prostate cancer, pancreatic cancer, ovarian cancer, and glioma. Altered MAFG-AS1 levels are also associated with diverse clinical characteristics and patient outcomes. Mechanistically, MAFG-AS1 mediates a variety of cellular processes via the regulation of target gene expression. Therefore, the diagnostic, prognostic, and therapeutic aspects of MAFG-AS1 have been widely explored. In this review, we discuss the expression, major roles, and molecular mechanisms of MAFG-AS1, the relationship between MAFG-AS1 and clinical features of diseases, and the clinical applications of MAFG-AS1.

The dual role of citrate in cancer

Citrate is a key metabolite of the Krebs cycle that can also be exported in the cytosol, where it performs several functions. In normal cells, citrate sustains protein acetylation, lipid synthesis, gluconeogenesis, insulin secretion, bone tissues formation, spermatozoid mobility, and immune response. Dysregulation of citrate metabolism is implicated in several pathologies, including cancer. Here we discuss how cancer cells use citrate to sustain their proliferation, survival, and metastatic progression. Also, we propose two paradoxically opposite strategies to reduce tumour growth by targeting citrate metabolism in preclinical models. In the first strategy, we propose to administer in the tumor microenvironment a high amount of citrate, which can then act as a glycolysis inhibitor and apoptosis inducer, whereas the other strategy targets citrate transporters to starve cancer cells from citrate. These strategies, effective in several preclinical in vitro and in vivo cancer models, could be exploited in clinics, particularly to increase sensibility to current anti-cancer agents.

Inverse correlation between Alzheimer's disease and cancer from the perspective of hypoxia

Sporadic Alzheimer's disease and cancer remain epidemiologically inversely related, and exploring the reverse pathogenesis is important for our understanding of both. Cognitive dysfunctions in Alzheimer's disease (AD) might result from the depletion of adaptive reserves in the brain. Energy storage in the brain is limited and is dynamically regulated by neurovascular and neurometabolic coupling. The research on neurodegenerative diseases has been dominated by the neurocentric view that neuronal defects cause the diseases. However, the proposal of the 2-hit vascular hypothesis in AD led us to focus on alterations in the vasculature, especially hypoperfusion. Chronic hypoxia is a feature shared by AD and cancer. It is interesting how contradicting chronic hypoxia's effects on both cancer and AD are. In this article, we discuss the potential links between the 2 diseases' etiology, from comparable upstream circumstances to diametrically opposed downstream effects. We suggest opposing potential mechanisms, including upregulation and downregulation of hypoxia-inducible factor-1α, the Warburg and reverse-Warburg effects, lactate-mediated intracellular acidic and alkaline conditions, and VDAC1-mediated apoptosis and antiapoptosis, and search for regulators that may be identified as the crossroads between cancer and AD.

Cancer Cachexia: Underlying Mechanisms and Potential Therapeutic Interventions

Cancer cachexia, a multifactorial metabolic syndrome developed during malignant tumor growth, is characterized by an accelerated loss of body weight accompanied by the depletion of skeletal muscle mass. This debilitating condition is associated with muscle degradation, impaired immune function, reduced functional capacity, compromised quality of life, and diminished survival in cancer patients. Despite the lack of the known capability of fully reversing or ameliorating this condition, ongoing research is shedding light on promising preclinical approaches that target the disrupted mechanisms in the pathophysiology of cancer cachexia. This comprehensive review delves into critical aspects of cancer cachexia, including its underlying pathophysiological mechanisms, preclinical models for studying the progression of cancer cachexia, methods for clinical assessment, relevant biomarkers, and potential therapeutic strategies. These discussions collectively aim to contribute to the evolving foundation for effective, multifaceted counteractive strategies against this challenging condition.

Stereospecificity of Ginsenoside AD-1 and AD-2 Showed Anticancer Activity via Inducing Mitochondrial Dysfunction and Reactive Oxygen Species Mediate Cell Apoptosis

In this paper, the anti-cancer activity and molecular mechanisms of the isomers of AD-1 and AD-2 (20(R)-AD-1, 20(R)-AD-2, 20(S)-AD-1 and 20(S)-AD-2) were investigated. The results indicated that all of the four compounds obviously suppressed the viability of various cancer cells, and the anti-cancer activity of 20(R)-AD-1 and 20(R)-AD-2 was significantly better than 20(S)-AD-1 and 20(S)-AD-2, especially for gastric cancer cells (BGC-803). Then, the differences in the anti-cancer mechanisms of the isomers were investigated. The data showed that 20(R)-AD-1 and 20(R)-AD-2 induced apoptosis and decreased MMP, up-regulated the expression of cytochrome C in cytosol, transferred Bax to the mitochondria, suppressed oxidative phosphorylation and glycolysis and stimulated reactive oxygen species (ROS) production. Apoptosis can be attenuated by the reactive oxygen species scavenger N-acetylcysteine. However, 20(S)-AD-1 and 20(S)-AD-2 barely exhibited the same results. The results indicated that 20(R)-AD-1 and 20(R)-AD-2 suppressed cellular energy metabolism and caused apoptosis through the mitochondrial pathway, which ROS generation was probably involved in. Above all, the data support the development of 20(R)-AD-1 and 20(R)-AD-2 as potential agents for human gastric carcinoma therapy.

Mitochondrial dysfunction and drug targets in multiple myeloma

Multiple myeloma (MM) is the second most common hematological cancer that has no cure. Although currently there are several novel drugs, most MM patients experience drug resistance and disease relapse. The results of previous studies suggest that aberrant mitochondrial function may contribute to tumor progression and drug resistance. Mitochondrial DNA mutations and metabolic reprogramming have been reported in MM patients. Several preclinical and clinical studies have shown encouraging results of mitochondria-targeting therapy in MM patients. In this review, we have summarized our current understanding of mitochondrial biology in MM. More importantly, we have reviewed mitochondrial targeting strategies in MM treatment.

Integrated analyses reveal the prognostic, immunological features and mechanisms of cuproptosis critical mediator gene FDX1 in KIRC

The ferredoxin 1 (FDX1) gene had been recently reported as a critical mediator of cuproptosis, and without doubt, its roles in KIRC would be of importance. Hence, this paper was to explore the roles of FDX1 in kidney renal clear cell carcinoma (KIRC) and its potential molecular mechanisms via scRNA-sequencing and bulk RNA-sequencing analyses. FDX1 was lowly expressed in KIRC and validated both at the protein and mRNA levels (all p < 0.05). Moreover, its elevated expression was linked with a better overall survival (OS) prognosis in KIRC (p < 0.01). The independent impact of FDX1 on KIRC prognosis was demonstrated by univariate/multivariate regression analysis (p < 0.01). Gene set enrichment analysis (GSEA) identified seven pathways strongly associated with FDX1 in KIRC. Furthermore, FDX1 was also revealed to be significantly related with immunity (p < 0.05). In addition, patients with low expression of FDX1 might be more sensitive to immunotherapies. ScRNA-seq analysis found that FDX1 could be expressed in immune cells and was mainly differently expressed in Mono/Macro cells. Ultimately, we also identified several LncRNA/RBP/FDX1 mRNA networks to reveal its underlying mechanisms in KIRC. Taken together, FDX1 was closely related to prognosis and immunity in KIRC, and its RBP-involved mechanisms of LncRNA/RBP/FDX1 networks were also revealed by us.

The role and molecular mechanism of metabolic reprogramming of colorectal cancer by UBR5 through PYK2 regulation of OXPHOS expression study

Colorectal carcinoma (CRC) is the third most malignant tumor in the world, but the key mechanisms of CRC progression have not been confirmed. UBR5 and PYK2 expression levels were detected by RT-qPCR. The levels of UBR5, PYK2, and mitochondrial oxidative phosphorylation (OXPHOS) complexes were detected by western blot analysis. Flow cytometry was used to detect ROS activity. The CCK-8 assay was used to assess cell proliferation and viability. The interaction between UBR5 and PYK2 was detected by immunoprecipitation. A clone formation assay was used to determine the cell clone formation rate. The ATP level and lactate production of each group of cells were detected by the kit. EdU staining was performed for cell proliferation.Transwell assay was performed for cell migration ability. For the CRC nude mouse model, we also observed and recorded the volume and mass of tumor-forming tumors. The expression of UBR5 and PYK2 was elevated in both CRC and human colonic mucosal epithelial cell lines, and knockdown of UBR5 had inhibitory effects on cancer cell proliferation and cloning and other behaviors in the CRC process by knockdown of UBR5 to downregulate the expression of PYK2, thus inhibiting the OXPHOS process in CRC; rotenone (OXPHOS inhibitor) treatment enhanced all these inhibitory effects. Knockdown of UBR5 can reduce the expression level of PYK2, thus downregulating the OXPHOS process in CRC cell lines and inhibiting the CRC metabolic reprogramming process.

The Interplay between Dysregulated Metabolism and Epigenetics in Cancer

Cellular metabolism (or energetics) and epigenetics are tightly coupled cellular processes. It is arguable that of all the described cancer hallmarks, dysregulated cellular energetics and epigenetics are the most tightly coregulated. Cellular metabolic states regulate and drive epigenetic changes while also being capable of influencing, if not driving, epigenetic reprogramming. Conversely, epigenetic changes can drive altered and compensatory metabolic states. Cancer cells meticulously modify and control each of these two linked cellular processes in order to maintain their tumorigenic potential and capacity. This review aims to explore the interplay between these two processes and discuss how each affects the other, driving and enhancing tumorigenic states in certain contexts.

Development of isoselenazolium chlorides as selective pyruvate kinase isoform M2 inhibitors

Alterations in cancer metabolic pathways open up an opportunity for targeted and effective elimination of tumor cells. Pyruvate kinase M2 (PKM2) is predominantly expressed in proliferating cells and plays an essential role in directing glucose metabolism in cancer. Here, we report the design of novel class of selective PKM2 inhibitors as anti-cancer agents and their mechanism of action. Compound 5c being the most active with IC₅₀ = 0.35 ± 0.07 μM, also downregulates PKM2 mRNA expression, modulates mitochondrial functionality, induces oxidative burst and is cytotoxic for various cancer types. Isoselenazolium chlorides have an unusual mechanism of PKM2 inhibition, inducing a functionally deficient tetrameric assembly, while exhibiting a competitive inhibitor character. The discovery of robust PKM2 inhibitors not only offers candidates for anticancer therapy but is also crucial for studying the role of PKM2 in cancer.

Metabolic Rewiring and Stemness: A Critical Attribute of Pancreatic Cancer Progression

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive diseases with a poor 5-year survival rate. PDAC cells rely on various metabolic pathways to fuel their unlimited proliferation and metastasis. Reprogramming glucose, fatty acid, amino acid, and nucleic acid metabolisms contributes to PDAC cell growth. Cancer stem cells are the primary cell types that play a critical role in the progression and aggressiveness of PDAC. Emerging studies indicate that the cancer stem cells in PDAC tumors are heterogeneous and show specific metabolic dependencies. In addition, understanding specific metabolic signatures and factors that regulate these metabolic alterations in the cancer stem cells of PDAC paves the way for developing novel therapeutic strategies targeting CSCs. In this review, we discuss the current understanding of PDAC metabolism by specifically exploring the metabolic dependencies of cancer stem cells. We also review the current knowledge of targeting these metabolic factors that regulate CSC maintenance and PDAC progression.