Mitochondrial genome acquisition restores respiratory function and tumorigenic potential of cancer cells without mitochondrial DNA

MSC-mediated mitochondrial transfer promotes metabolic reprograming in endothelial cells and vascular regeneration in ARDS

BACKGROUND

Mesenchymal stem cells (MSCs) are a potential therapy for acute respiratory distress syndrome (ARDS), but their mechanisms in repairing mitochondrial damage in ARDS endothelial cells remain unclear.

METHODS

We first examined MSCs' mitochondrial transfer ability and mechanisms to mouse pulmonary microvascular endothelial cells (MPMECs) in ARDS. Then, we investigated how MSC-mediated mitochondrial transfer affects the repair of endothelial damage. Finally, we elucidated the mechanisms by which MSC-mediated mitochondrial transfer promotes vascular regeneration.

RESULTS

Compared to mitochondrial-damaged MSCs, normal MSCs showed a significantly higher mitochondrial transfer rate to MPMECs, with increases of 41.68% in vitro (P < 0.0001) and 10.50% in vivo (P = 0.0005). Furthermore, MSC-mediated mitochondrial transfer significantly reduced reactive oxygen species (P < 0.05) and promoted proliferation (P < 0.0001) in MPMECs. Finally, MSC-mediated mitochondrial transfer significantly increased the activity of the tricarboxylic acid (TCA) cycle (MD of CS mRNA: 23.76, P = 0.032), and further enhanced fatty acid synthesis (MD of FAS mRNA: 6.67, P = 0.0001), leading to a 6.7-fold increase in vascular endothelial growth factor release from MPMECs and promoted vascular regeneration in ARDS.

CONCLUSION

MSC-mediated mitochondrial transfer to MPMECs activates the TCA cycle and fatty acid synthesis, promoting endothelial proliferation and pro-angiogenic factor release, thereby enhancing vascular regeneration in ARDS.

Connecting the dots: Mitochondrial transfer in immunity, inflammation, and cancer

Mitochondria are more than mere energy generators; they are multifaceted organelles that integrate metabolic, signalling, and immune functions, making them indispensable players in maintaining cellular and systemic health. Mitochondrial transfer has recently garnered attention due to its potential role in several physiological and pathological processes. This process involves multiple mechanisms by which mitochondria, along with mitochondrial DNA and other components, are exchanged between cells. In this review, we examine the critical roles of mitochondrial transfer in health and disease, focusing on its impact on immune cell function, the resolution of inflammation, tissue repair, and regeneration. Additionally, we explore its implications in viral infections and cancer progression. We also provide insights into emerging therapeutic applications, emphasizing its potential to address unmet clinical needs.

Mesenchymal stem cell-mediated mitochondrial transfer regulates the fate of B lymphocytes

BACKGROUND

Mitochondrial transfer is becoming recognized as an important immunomodulatory mechanism used by mesenchymal stem cells (MSCs) to influence immune cells. While effects on T cells and macrophages have been documented, the influence on B cells remains unexplored. This study investigates the modulation of B lymphocyte fate by MSC-mediated mitochondrial transfer.

METHODS

MSCs labelled with MitoTracker dyes or derived from mito::mKate2 transgenic mice were co-cultured with splenocytes. Flow cytometry assessed mitochondrial transfer, reactive oxygen species (ROS) levels, apoptosis and mitophagy. Glucose uptake was measured using the 2-NBDG assay. RNA sequencing analysed gene expression changes in CD19+ mitochondria recipients and nonrecipients. Pathway analysis identified affected processes. In an LPS-induced inflammation model, mito::mKate2 MSCs were administered, and B cells from different organs were analysed for mitochondrial uptake and phenotypic changes. MSC-derived mitochondria were also isolated to confirm uptake by FACS-sorted CD19+ cells.

RESULTS

MSCs transferred mitochondria to CD19+ cells, though less than to other immune cells. Transfer correlated with ROS levels and mitophagy induction. Mitochondria were preferentially acquired by activated B cells, as indicated by increased CD69 expression and glycolytic activity. Bidirectional transfer occurred, with immune cells exchanging dysfunctional mitochondria for functional ones. CD19+ recipients exhibited increased viability, proliferation and altered gene expression, with upregulated cell division genes and downregulated antigen presentation genes. In vivo, mitochondrial acquisition reduced B cell activation and inflammatory cytokine production. Pre-sorted B cells also acquired isolated mitochondria, exhibiting a similar anti-inflammatory phenotype.

CONCLUSIONS

These findings highlight mitochondrial trafficking as a key MSC-immune cell interaction mechanism with immunomodulatory therapeutic potential.

Horizontal mitochondrial transfer in cancer biology: Potential clinical relevance

Recent research highlights horizontal mitochondrial transfer as a key biological phenomenon linked to cancer onset and progression. The transfer of mitochondria and their genomes between cancer and non-cancer cells shifts our understanding of intercellular gene trafficking, increasing the metabolic fitness of cancer cells and modulating antitumor immune responses. This process not only facilitates tumor progression but also presents potential therapeutic opportunities.

Targeting mitochondrial transfer as a promising therapeutic strategy

Despite the primary impression of mitochondria as energy factories, these organelles are increasingly recognized for their multifaceted roles beyond energy production. Intriguingly, mitochondria can transfer between cells, influencing physiological and pathological processes through intercellular trafficking termed 'mitochondrial transfer.' This phenomenon is important in maintaining metabolic homeostasis, enhancing tissue regeneration, exacerbating cancer progression, and facilitating immune modulation, depending on the cell type and microenvironment. Recently, mitochondrial transfer has emerged as a promising therapeutic target for tissue repair and antitumor therapy. Here, we summarize and critically review recent advances in this field. We aim to provide an updated overview of the mechanisms and potential therapeutic avenues associated with mitochondrial transfer in various diseases from the perspective of different donor cells.

Functional mitochondrial respiration is essential for glioblastoma tumour growth

Horizontal transfer of mitochondria from the tumour microenvironment to cancer cells to support proliferation and enhance tumour progression has been shown for various types of cancer in recent years. Glioblastoma, the most aggressive adult brain tumour, has proven to be no exception when it comes to dynamic intercellular mitochondrial movement, as shown in this study using an orthotopic tumour model of respiration-deficient glioblastoma cells. Although confirmed mitochondrial transfer was shown to facilitate tumour progression in glioblastoma, we decided to investigate whether the related electron transport chain recovery is necessary for tumour formation in the brain. Based on experiments using time-resolved analysis of tumour formation by glioblastoma cells depleted of their mitochondrial DNA, we conclude that functional mitochondrial respiration is essential for glioblastoma growth in vivo, because it is needed to support coenzyme Q redox cycling for de novo pyrimidine biosynthesis controlled by respiration-linked dihydroorotate dehydrogenase enzyme activity. We also demonstrate here that astrocytes are key mitochondrial donors in this model.

Metabolic crosstalk between platelets and cancer: Mechanisms, functions, and therapeutic potential

Platelets, traditionally regarded as passive mediators of hemostasis, are now recognized as pivotal regulators in the tumor microenvironment, establishing metabolic feedback loops with tumor and immune cells. Tumor-derived signals trigger platelet activation, which induces rapid metabolic reprogramming, particularly glycolysis, to support activation-dependent functions such as granule secretion, morphological changes, and aggregation. Beyond self-regulation, platelets influence the metabolic processes of adjacent cells. Through direct mitochondrial transfer, platelets reprogram tumor and immune cells, promoting oxidative phosphorylation. Additionally, platelet-derived cytokines, granules, and extracellular vesicles drive metabolic alterations in immune cells, fostering suppressive phenotypes that facilitate tumor progression. This review examines three critical aspects: (1) the distinctive metabolic features of platelets, particularly under tumor-induced activation; (2) the metabolic crosstalk between activated platelets and other cellular components; and (3) the therapeutic potential of targeting platelet metabolism to disrupt tumor-promoting networks. By elucidating platelet metabolism, this review highlights its essential role in tumor biology and its therapeutic implications.

Screening of patient-derived organoids identifies mitophagy as a cell-intrinsic vulnerability in colorectal cancer during statin treatment

Statins, commonly used to lower cholesterol, are associated with improved prognosis in colorectal cancer (CRC), though their effectiveness varies. This study investigates the anti-cancer effects of atorvastatin in CRC using patient-derived organoids (PDOs) and PDO-derived xenograft (PDOX) models. Our findings reveal that atorvastatin induces mitochondrial dysfunction, leading to apoptosis in cancer cells. In response, cancer cells induce mitophagy to clear damaged mitochondria, enhancing survival and reducing statin efficacy. Analysis of a clinical cohort confirms mitophagy's role in diminishing statin effectiveness. Importantly, inhibiting mitophagy significantly enhances the anti-cancer effects of atorvastatin in CRC PDOs, xenograft models, and azoxymethane (AOM)-dextran sulfate sodium (DSS) mouse models. These findings identify mitophagy as a critical pro-survival mechanism in CRC during statin treatment, providing insights into the variable responses observed in epidemiological studies. Targeting this vulnerability through combination therapy can elicit potent therapeutic responses.

Bezafibrate-driven mitochondrial targeting enhances antitumor immunity and prevents lung cancer via CD8+ T cell infiltration and MDSC reduction

Bezafibrate (BEZ) is a drug used to treat hypertriglyceridemia and its long-term use has been associated with reduced risk of cancer in patients with coronary artery disease. Recent studies uncovered that BEZ is a potent modulator of mitochondrial biogenesis through activation of PGC-1α/PPAR complexes, resulting in modulation of lipid metabolism and fatty acid oxidation. Mitochondria impact virtually all processes linked to oncogenesis, and disruption of normal mitochondrial bioenergetics and oxidative phosphorylation (OXPHOS) occurs early during oncogenesis to change the energy metabolism of cancer cells as well as various cells in the tumor microenvironment (TME). Therefore, we synthesized a BEZ analog (Mito-BEZ) that preferentially localizes to mitochondria, thereby enabling lower doses of Mito-BEZ than BEZ to achieve greater efficacy. Our studies demonstrate that Mito-BEZ is significantly more potent than BEZ at inhibiting LUAD cell growth in vitro and inhibiting lung tumorigenesis in preclinical mouse models. Mito-BEZ was also >200-fold more potent than BEZ at inhibiting both complex I and III in LUAD cells. Furthermore, Mito-BEZ suppresses oxidative metabolism in cancer cells while markedly upregulating mitochondrial function in effector CD8+ T cells, resulting in activation of a potent T cell immune response in the TME. Our results show that Mito-BEZ, with its favorable toxicity profile, exhibited a striking inhibitory effect on lung cancer progression and metastasis by targeting a fundamental difference in metabolic plasticity between cancer cells and effector T cells in the TME.

Cancer Biology and the Perioperative Period: Opportunities for Disease Evolution and Challenges for Perioperative Care

Efforts to deconvolve the complex interactions of cancer cells with other components of the tumor micro- and macro-environment have exposed a common tendency for cancers to subvert systems physiology and exploit endogenous programs involved in homeostatic control of metabolism, immunity, regeneration, and repair. Many such programs are engaged in the healing response to surgery which, together with other abrupt biochemical changes in the perioperative period, provide an opportunity for the macroevolution of residual disease. This review relates contemporary perspectives of cancer as a systemic disease with the overlapping biology of host responses to surgery and events within the perioperative period. With a particular focus on examples of cancer cell plasticity and changes within the host, we explore how perioperative inflammation and acute metabolic, neuroendocrine, and immune dyshomeostasis might contribute to cancer evolution within this contextually short, yet crucially influential timeframe, and highlight potential therapeutic opportunities within to further optimize surgical cancer care and its long-term oncological outcomes.

Accumulation of Damaging Lipids in the Arf1-Ablated Neurons Promotes Neurodegeneration through Releasing mtDNA and Activating Inflammatory Pathways in Microglia

Lipid metabolism disorders in both neurons and glial cells have been found in neurodegenerative (ND) patients and animal models. However, the pathological connection between lipid droplets and NDs remains poorly understood. The recent work has highlighted the utility of a neuron-specific Arf1-knockout mouse model and corresponding cells for elucidating the nexus between lipid metabolism disorders and amyotrophic lateral sclerosis (ALS) and multiple sclerosis (MS). In this study, it is found that Arf1 deficiency first induced surplus fatty acid synthesis through the AKT-mTORC1-SREBP1-FASN axis, which further triggered endoplasmic reticulum (ER)-mitochondrial stress cascade via calcium flux. The organelle stress cascade further caused mitochondrial DNA (mtDNA) to be released into cytoplasm. Concurrently, the FASN-driven fatty acid synthesis in the Arf1-deficient neurons might also induce accumulation of sphingolipids in lysosomes that caused dysfunction of autophagy and lysosomes, which further promoted lysosomal stress and mitochondria-derived extracellular vesicles (MDEVs) release. The released MDEVs carried mtDNA into microglia to activate the inflammatory pathways and neurodegeneration. The studies on neuronal lipid droplets (LDs) and recent studies of microglial LDs suggest a unified pathological function of LDs in NDs: activating the inflammatory pathways in microglia. This finding potentially provides new therapeutic strategies for NDs.

Metabolic landscape of disseminated cancer dormancy

Cancer dormancy is a phenomenon defined by the entry of cancer cells into a reversible quiescent, nonproliferative state, and represents an essential part of the metastatic cascade responsible for cancer recurrence and mortality. Emerging evidence suggests that metabolic reprogramming plays a pivotal role in enabling entry, maintenance, and exit from dormancy in the face of the different environments of the metastatic cascade. Here, we review the current literature to understand the dynamics of metabolism during dormancy, highlighting its fine-tuning by the host micro- and macroenvironment, and put forward the importance of identifying metabolic vulnerabilities of the dormant state as therapeutic targets to eradicate recurrent disease.

An Energy Metabolism Nanoblocker for Cutting Tumor Cell Respiration and Inhibiting Mitochondrial Hijacking from Cytotoxic T Lymphocyte

Energy metabolism modulation emerges as a highly regarded strategy for tumor therapy. However, the efficacy of targeting energy metabolism in tumor cells remains unsatisfactory due to the alternate energy production pathways by switching between mitochondrial respiration and glycolysis. In addition, tumor cells can hijack mitochondria from peripheral immune cells to maintain their energy metabolism as an extra respiratory pathway. In this study, a CD44 receptor-targeted hyaluronic acid energy metabolism nanoblocker is developed to achieve bidirectional blockade of basal respiration in tumor cells with the loaded mitochondrial oxidative phosphorylation (OXPHOS) inhibitor nebivolol hydrochloride, and the glycolysis inhibitor 3-bromopyruvate. Furthermore, combined intraperitoneal injection of L-778123 hydrochloride inhibits mitochondrial transfer, thus blocking the extra respiratory pathway of tumor cells and the depletion of cytotoxic T lymphocytes. This emerging strategy, which involves depleting tumor cell energy through inhibition of basal respiration (OXPHOS/glycolysis) and extra respiration, while synergistically enhancing effector immune cells to maintain systemic anti-tumor immune effects, demonstrates high efficacy and safety in both in vitro and in vivo experiments. It provides a conceptual paradigm shift in nanomedicine-mediated energy metabolism-based tumor therapy.

Development of a cell-penetrating peptide-based nanocomplex for long-term delivery of intact mitochondrial DNA into epithelial cells

Gene therapy approaches for mitochondrial DNA (mtDNA)-associated damage/diseases have thus far been limited, and despite advancements in single gene therapy for mtDNA mutations and progress in mitochondrial transplantation, no method exists for restoring the entire mtDNA molecule in a clinically translatable manner. Here, we present for the first time a strategy to deliver an exogenous, fully intact, and healthy mtDNA template into cells to correct endogenous mtDNA mutations and deletions, with the potential to be developed into an efficient pan-therapy for inherited and/or acquired mtDNA disorders. More specifically, the novel therapeutic nanoparticle complex used in our study was generated by combining a cell-penetrating peptide (CPP) with purified mtDNA, in conjunction with a mitochondrial targeting reagent. The generated nanoparticle complexes were found to be taken up by cells and localized to mitochondria, with exogenous mtDNA retention/maintenance, along with mitochondrial RNA and protein production, observed in mitochondria-depleted ARPE-19 cells at least 4 weeks following a single treatment. These data demonstrate the feasibility of restoring mtDNA in cells via a CPP carrier, with the therapeutic potential to correct mtDNA damage independent of the number of gene mutations found within the mtDNA.

Engineered mitochondria in diseases: mechanisms, strategies, and applications

Mitochondrial diseases represent one of the most prevalent and debilitating categories of hereditary disorders, characterized by significant genetic, biological, and clinical heterogeneity, which has driven the development of the field of engineered mitochondria. With the growing recognition of the pathogenic role of damaged mitochondria in aging, oxidative disorders, inflammatory diseases, and cancer, the application of engineered mitochondria has expanded to those non-hereditary contexts (sometimes referred to as mitochondria-related diseases). Due to their unique non-eukaryotic origins and endosymbiotic relationship, mitochondria are considered highly suitable for gene editing and intercellular transplantation, and remarkable progress has been achieved in two promising therapeutic strategies-mitochondrial gene editing and artificial mitochondrial transfer (collectively referred to as engineered mitochondria in this review) over the past two decades. Here, we provide a comprehensive review of the mechanisms and recent advancements in the development of engineered mitochondria for therapeutic applications, alongside a concise summary of potential clinical implications and supporting evidence from preclinical and clinical studies. Additionally, an emerging and potentially feasible approach involves ex vivo mitochondrial editing, followed by selection and transplantation, which holds the potential to overcome limitations such as reduced in vivo operability and the introduction of allogeneic mitochondrial heterogeneity, thereby broadening the applicability of engineered mitochondria.

The role of mitochondria transfer in cancer biological behavior, the immune system and therapeutic resistance

Mitochondria play a crucial role as organelles, managing several physiological processes such as redox balance, cell metabolism, and energy synthesis. Initially, the assumption was that mitochondria primarily resided in the host cells and could exclusively transmit from oocytes to offspring by a mechanism known as vertical inheritance of mitochondria. Recent scholarly works, however, suggest that certain cell types transmit their mitochondria to other developmental cell types via a mechanism referred to as intercellular or horizontal mitochondrial transfer. This review details the process of which mitochondria are transferred across cells and explains the impact of mitochondrial transfer between cells on the efficacy and functionality of cancer cells in various cancer forms. Specifically, we review the role of mitochondria transfer in regulating cellular metabolism restoration, excess reactive oxygen species (ROS) generation, proliferation, invasion, metastasis, mitophagy activation, mitochondrial DNA (mtDNA) inheritance, immune system modulation and therapeutic resistance in cancer. Additionally, we highlight the possibility of using intercellular mitochondria transfer as a therapeutic approach to treat cancer and enhance the efficacy of cancer treatments.

Biguanides antithetically regulate tumor properties by the dose-dependent mitochondrial reprogramming-driven c-Src pathway

The biguanide metformin attenuates mitochondrial oxidation and is proposed as an anti-cancer therapy. However, recent clinical studies suggest increased proliferation and fatty acid β-oxidation (FAO) in a subgroup of patients with breast cancer (BC) after metformin therapy. Considering that FAO can activate Src kinase in aggressive triple-negative BC (TNBC), we postulate that low-dose biguanide-driven AMPK-ACC-FAO signaling may activate the Src pathway in TNBC. The low bioavailability of metformin in TNBC xenografts mimics metformin's in vitro low-dose effect. Pharmacological or genetic inhibition of FAO significantly enhances the anti-tumor properties of biguanides. Lower doses of biguanides induce and higher doses suppress Src signaling. Dasatinib and metformin synergistically inhibit TNBC patient-derived xenograft growth, but not in high-fat diet-fed mice. This combination also suppresses TNBC metastatic progression. A combination of biguanides with Src inhibitors provides synergy to target metastatic TNBC suffering with limited treatment options.

The promise of mitochondria in the treatment of glioblastoma: a brief review

Glioblastoma (GBM) is a prevalent and refractory type of brain tumor. Over the past two decades, there have been minimal advancements in GBM therapy. The current standard treatment involves surgical excision followed by radiation and chemotherapy. Compared to other tumors, GBM is more challenging to treat due to the presence of glioma stem-like cells (GSCs) and the blood-brain barrier, resulting in an extremely low survival rate. Mitochondria play a critical role in tumor respiration, metabolism, and multiple signaling pathways involved in tumor formation, progression, and cell apoptosis. Consequently, mitochondria represent promising targets for developing novel anticancer agents, including those targeting oxidative phosphorylation, reactive oxygen species (ROS), mitochondrial transfer, and mitophagy. This review outlines the mitochondrial-related therapeutic targets in GBM, highlighting the potential of mitochondria as a target for GBM treatment.

Metabolic rewiring in skin epidermis drives tolerance to oncogenic mutations

Skin epithelial stem cells correct aberrancies induced by oncogenic mutations. Oncogenes invoke different strategies of epithelial tolerance; while wild-type cells outcompete β-catenin-gain-of-function (βcatGOF) cells, HrasG12V cells outcompete wild-type cells. Here we ask how metabolic states change as wild-type stem cells interface with mutant cells and drive different cell-competition outcomes. By tracking the endogenous redox ratio (NAD(P)H/FAD) with single-cell resolution in the same mouse over time, we discover that βcatGOF and HrasG12V mutations, when interfaced with wild-type epidermal stem cells, lead to a rapid drop in redox ratios, indicating more oxidized cellular redox. However, the resultant redox differential persists through time in βcatGOF, whereas it is flattened rapidly in the HrasG12Vmodel. Using 13C liquid chromatography-tandem mass spectrometry, we find that the βcatGOF and HrasG12V mutant epidermis increase the fractional contribution of glucose through the oxidative tricarboxylic acid cycle. Treatment with metformin, a modifier of cytosolic redox, inhibits downstream mutant phenotypes and reverses cell-competition outcomes of both mutant models.

Immune evasion through mitochondrial transfer in the tumour microenvironment

Cancer cells in the tumour microenvironment use various mechanisms to evade the immune system, particularly T cell attack1. For example, metabolic reprogramming in the tumour microenvironment and mitochondrial dysfunction in tumour-infiltrating lymphocytes (TILs) impair antitumour immune responses2-4. However, detailed mechanisms of such processes remain unclear. Here we analyse clinical specimens and identify mitochondrial DNA (mtDNA) mutations in TILs that are shared with cancer cells. Moreover, mitochondria with mtDNA mutations from cancer cells are able to transfer to TILs. Typically, mitochondria in TILs readily undergo mitophagy through reactive oxygen species. However, mitochondria transferred from cancer cells do not undergo mitophagy, which we find is due to mitophagy-inhibitory molecules. These molecules attach to mitochondria and together are transferred to TILs, which results in homoplasmic replacement. T cells that acquire mtDNA mutations from cancer cells exhibit metabolic abnormalities and senescence, with defects in effector functions and memory formation. This in turn leads to impaired antitumour immunity both in vitro and in vivo. Accordingly, the presence of an mtDNA mutation in tumour tissue is a poor prognostic factor for immune checkpoint inhibitors in patients with melanoma or non-small-cell lung cancer. These findings reveal a previously unknown mechanism of cancer immune evasion through mitochondrial transfer and can contribute to the development of future cancer immunotherapies.

Research progress of mitochondria and cytoskeleton crosstalk in tumour development

During tumour progression, organelle function undergoes dramatic changes, and crosstalk among organelles plays a significant role. Crosstalk between mitochondria and other organelles such as the endoplasmic reticulum and cytoskeleton has focussed attention on the mechanisms of tumourigenesis. This review demonstrates an overview of the molecular structure of the mitochondrial-cytoskeletal junction and its biological interactions. It also presents a detailed and comprehensive description of mitochondrial-cytoskeletal crosstalk in tumour occurrence and development, including tumour cell proliferation, apoptosis, autophagy, metabolic rearrangement, and metastasis. Finally, the application of crosstalk in tumour therapy, including drug combinations and chemoresistance, is discussed. This review offers a theoretical basis for establishing mitochondrial-cytoskeletal junctions as therapeutic targets, and offers novel insights into the future management of malignant tumours.

The adaptor protein Miro1 modulates horizontal transfer of mitochondria in mouse melanoma models

Recent research has shown that mtDNA-deficient cancer cells (ρ0 cells) acquire mitochondria from tumor stromal cells to restore respiration, facilitating tumor formation. We investigated the role of Miro1, an adaptor protein involved in movement of mitochondria along microtubules, in this phenomenon. Inducible Miro1 knockout (Miro1KO) mice markedly delayed tumor formation after grafting ρ0 cancer cells. Miro1KO mice with fluorescently labeled mitochondria revealed that this delay was due to hindered mitochondrial transfer from the tumor stromal cells to grafted B16 ρ0 cells, which impeded recovery of mitochondrial respiration and tumor growth. Miro1KO led to the perinuclear accumulation of mitochondria and impaired mobility of the mitochondrial network. In vitro experiments revealed decreased association of mitochondria with microtubules, compromising mitochondrial transfer via tunneling nanotubes (TNTs) in mesenchymal stromal cells. Here we show the role of Miro1 in horizontal mitochondrial transfer in mouse melanoma models in vivo and its involvement with TNTs.

Exercise-induced extracellular vesicles in reprogramming energy metabolism in cancer

Cancer is caused by complex interactions between genetic, environmental, and lifestyle factors, making prevention strategies, including exercise, a promising avenue for intervention. Physical activity is associated with reduced cancer incidence and progression and systemic anti-cancer effects, including improved tumor suppression and prolonged survival in preclinical models. Exercise impacts the body's nutrient balance and stimulates the release of several exercise-induced factors into circulation. The mechanisms of how exercise modulates cancer energy metabolism and the tumor microenvironment through systemic effects mediated, in part, by extracellular vesicles (EVs) are still unknown. By transferring bioactive cargo such as miRNAs, proteins and metabolites, exercise-induced EVs may influence cancer cells by altering glycolysis and oxidative phosphorylation, potentially shifting metabolic plasticity - a hallmark of cancer. This short review explores the roles of EVs in cancer as mediators to reprogram cellular energy metabolism through exchanging information inside the tumor microenvironment, influencing immune cells, fibroblast and distant cells. Considering this knowledge, further functional studies into exercise-induced EVs and cellular energy production pathways could inform more specific exercise interventions to enhance cancer therapy and improve patient outcomes.

Somatic mtDNA mutation burden shapes metabolic plasticity in leukemogenesis

The role of somatic mitochondrial DNA (mtDNA) mutations in leukemogenesis remains poorly characterized. To determine the impact of somatic mtDNA mutations on this process, we assessed the leukemogenic potential of hematopoietic progenitor cells (HPCs) from mtDNA mutator mice (Polg D257A) with or without NMyc overexpression. We observed a higher incidence of spontaneous leukemogenesis in recipients transplanted with heterozygous Polg HPCs and a lower incidence of NMyc-driven leukemia in those with homozygous Polg HPCs compared to controls. Although mtDNA mutations in heterozygous and homozygous HPCs caused similar baseline impairments in mitochondrial function, only heterozygous HPCs responded to and supported altered metabolic demands associated with NMyc overexpression. Homozygous HPCs showed altered glucose utilization with pyruvate dehydrogenase inhibition due to increased phosphorylation, exacerbated by NMyc overexpression. The impaired growth of NMyc-expressing homozygous HPCs was partially rescued by inhibiting pyruvate dehydrogenase kinase, highlighting a relationship between mtDNA mutation burden and metabolic plasticity in leukemogenesis.

Recommendations for mitochondria transfer and transplantation nomenclature and characterization

Intercellular mitochondria transfer is an evolutionarily conserved process in which one cell delivers some of their mitochondria to another cell in the absence of cell division. This process has diverse functions depending on the cell types involved and physiological or disease context. Although mitochondria transfer was first shown to provide metabolic support to acceptor cells, recent studies have revealed diverse functions of mitochondria transfer, including, but not limited to, the maintenance of mitochondria quality of the donor cell and the regulation of tissue homeostasis and remodelling. Many mitochondria-transfer mechanisms have been described using a variety of names, generating confusion about mitochondria transfer biology. Furthermore, several therapeutic approaches involving mitochondria-transfer biology have emerged, including mitochondria transplantation and cellular engineering using isolated mitochondria. In this Consensus Statement, we define relevant terminology and propose a nomenclature framework to describe mitochondria transfer and transplantation as a foundation for further development by the community as this dynamic field of research continues to evolve.

Mitochondrial DNA damage, repair, and replacement in cancer

Mitochondria are vital organelles with their own DNA (mtDNA). mtDNA is circular and composed of heavy and light chains that are structurally more accessible than nuclear DNA (nDNA). While nDNA is typically diploid, the number of mtDNA copies per cell is higher and varies considerably during development and between tissues. Compared with nDNA, mtDNA is more prone to damage that is positively linked to many diseases, including cancer. Similar to nDNA, mtDNA undergoes repair processes, although these mechanisms are less well understood. In this review, we discuss the various forms of mtDNA damage and repair and their association with cancer initiation and progression. We also propose horizontal mitochondrial transfer as a novel mechanism for replacing damaged mtDNA.

Inter- and intracellular mitochondrial communication: signaling hubs in aging and age-related diseases

Mitochondria are versatile and complex organelles that can continuously communicate and interact with the cellular milieu. Deregulated communication between mitochondria and host cells/organelles has significant consequences and is an underlying factor of many pathophysiological conditions, including the process of aging. During aging, mitochondria lose function, and mitocellular communication pathways break down; mitochondrial dysfunction interacts with mitochondrial dyscommunication, forming a vicious circle. Therefore, strategies to protect mitochondrial function and promote effective communication of mitochondria can increase healthy lifespan and longevity, which might be a new treatment paradigm for age-related disorders. In this review, we comprehensively discuss the signal transduction mechanisms of inter- and intracellular mitochondrial communication, as well as the interactions between mitochondrial communication and the hallmarks of aging. This review emphasizes the indispensable position of inter- and intracellular mitochondrial communication in the aging process of organisms, which is crucial as the cellular signaling hubs. In addition, we also specifically focus on the status of mitochondria-targeted interventions to provide potential therapeutic targets for age-related diseases.

Mitochondria and Cancer

Mitochondria are semiautonomous organelles with diverse metabolic and cellular functions including anabolism and energy production through oxidative phosphorylation. Following the pioneering observations of Otto Warburg nearly a century ago, an immense body of work has examined the role of mitochondria in cancer pathogenesis and progression. Here, we summarize the current state of the field, which has coalesced around the position that functional mitochondria are required for cancer cell proliferation. In this review, we discuss how mitochondria influence tumorigenesis by impacting anabolism, intracellular signaling, and the tumor microenvironment. Consistent with their critical functions in tumor formation, mitochondria have become an attractive target for cancer therapy. We provide a comprehensive update on the numerous therapeutic modalities targeting the mitochondria of cancer cells making their way through clinical trials.

Transfer and fates of damaged mitochondria: role in health and disease

Intercellular communication is pivotal in mediating the transfer of mitochondria from donor to recipient cells. This process orchestrates various biological functions, including tissue repair, cell proliferation, differentiation and cancer invasion. Typically, dysfunctional and depolarized mitochondria are eliminated through intracellular or extracellular pathways. Nevertheless, increasing evidence suggests that intercellular transfer of damaged mitochondria is associated with the pathogenesis of diverse diseases. This review investigates the prevalent triggers of mitochondrial damage and the underlying mechanisms of mitochondrial transfer, and elucidates the role of directional mitochondrial transfer in both physiological and pathological contexts. Additionally, we propose potential previously unknown mechanisms mediating mitochondrial transfer and explore their prospective roles in disease prevention and therapy.

Deregulation of mitochondrial gene expression in cancer: mechanisms and therapeutic opportunities

"Reprogramming of energy metabolism" was first considered an emerging hallmark of cancer in 2011 by Hanahan & Weinberg and is now considered a core hallmark of cancer. Mitochondria are the hubs of metabolism, crucial for energetic functions and cellular homeostasis. The mitochondrion's bacterial origin and preservation of their own genome, which encodes proteins and RNAs essential to their function, make them unique organelles. Successful generation of mitochondrial gene products requires coordinated functioning of the mitochondrial 'central dogma,' encompassing all steps necessary for mtDNA to yield mitochondrial proteins. Each of these processes has several levels of regulation, including mtDNA accessibility and protection through mtDNA packaging and epigenetic modifications, mtDNA copy number through mitochondrial replication, mitochondrial transcription through mitochondrial transcription factors, and mitochondrial translation through mitoribosome formation. Deregulation of these mitochondrial processes in the context of cancers has only recently been appreciated, with most studies being correlative in nature. Nonetheless, numerous significant associations of the mitochondrial central dogma with pro-tumor phenotypes have been documented. Several studies have even provided mechanistic insights and further demonstrated successful pharmacologic targeting strategies. Based on the emergent importance of mitochondria for cancer biology and therapeutics, it is becoming increasingly important that we gain an understanding of the underpinning mechanisms so they can be successfully therapeutically targeted. It is expected that this mechanistic understanding will result in mitochondria-targeting approaches that balance anticancer potency with normal cell toxicity. This review will focus on current evidence for the dysregulation of mitochondrial gene expression in cancers, as well as therapeutic opportunities on the horizon.

Pathogenic mitochondrial DNA mutations inhibit melanoma metastasis

Mitochondrial DNA (mtDNA) mutations are frequent in cancer, yet their precise role in cancer progression remains debated. To functionally evaluate the impact of mtDNA variants on tumor growth and metastasis, we developed an enhanced cytoplasmic hybrid (cybrid) generation protocol and established isogenic human melanoma cybrid lines with wild-type mtDNA or pathogenic mtDNA mutations with partial or complete loss of mitochondrial oxidative function. Cybrids with homoplasmic levels of pathogenic mtDNA reliably established tumors despite dysfunctional oxidative phosphorylation. However, these mtDNA variants disrupted spontaneous metastasis from primary tumors and reduced the abundance of circulating tumor cells. Migration and invasion of tumor cells were reduced, indicating that entry into circulation is a bottleneck for metastasis amid mtDNA dysfunction. Pathogenic mtDNA did not inhibit organ colonization following intravenous injection. In heteroplasmic cybrid tumors, single-cell analyses revealed selection against pathogenic mtDNA during melanoma growth. Collectively, these findings experimentally demonstrate that functional mtDNA is favored during melanoma growth and supports metastatic entry into the blood.

Mitochondrial Extracellular Vesicles (mitoEVs): Emerging mediators of cell-to-cell communication in health, aging and age-related diseases

Mitochondria are metabolic and signalling hubs that integrate a plethora of interconnected processes to maintain cell homeostasis. They are also dormant mediators of inflammation and cell death, and with aging damages affecting mitochondria gradually accumulate, resulting in the manifestation of age-associated disorders. In addition to coordinate multiple intracellular functions, mitochondria mediate intercellular and inter-organ cross talk in different physiological and stress conditions. To fulfil this task, mitochondrial signalling has evolved distinct and complex conventional and unconventional routes of horizontal/vertical mitochondrial transfer. In this regard, great interest has been focused on the ability of extracellular vesicles (EVs), such as exosomes and microvesicles, to carry selected mitochondrial cargoes to target cells, in response to internal and external cues. Over the past years, the field of mitochondrial EVs (mitoEVs) has grown exponentially, revealing unexpected heterogeneity of these structures associated with an ever-expanding mitochondrial function, though the full extent of the underlying mechanisms is far from being elucidated. Therefore, emerging subsets of EVs encompass exophers, migrasomes, mitophers, mitovesicles, and mitolysosomes that can act locally or over long-distances to restore mitochondrial homeostasis and cell functionality, or to amplify disease. This review provides a comprehensive overview of our current understanding of the biology and trafficking of MitoEVs in different physiological and pathological conditions. Additionally, a specific focus on the role of mitoEVs in aging and the onset and progression of different age-related diseases is discussed.

Mitochondrial transfer from mesenchymal stem cells: Mechanisms and functions

Mesenchymal stem cells based therapy has been used in clinic for almost 20 years and has shown encouraging effects in treating a wide range of diseases. However, the underlying mechanism is far more complicated than it was previously assumed. Mitochondria transfer is one way that recently found to be employed by mesenchymal stem cells to exert its biological effects. As one way of exchanging mitochondrial components, mitochondria transfer determines both mesenchymal stem cells and recipient cell fates. In this review, we describe the factors that contribute to MSCs-MT. Then, the routes and mechanisms of MSCs-MT are summarized to provide a theoretical basis for MSCs therapy. Besides, the advantages and disadvantages of MSCs-MT in clinical application are analyzed.

Metabolic dysregulation of tricarboxylic acid cycle and oxidative phosphorylation in glioblastoma

Glioblastoma multiforme (GBM) exhibits genetic alterations that induce the deregulation of oncogenic pathways, thus promoting metabolic adaptation. The modulation of metabolic enzyme activities is necessary to generate nucleotides, amino acids, and fatty acids, which provide energy and metabolic intermediates essential for fulfilling the biosynthetic needs of glioma cells. Moreover, the TCA cycle produces intermediates that play important roles in the metabolism of glucose, fatty acids, or non-essential amino acids, and act as signaling molecules associated with the activation of oncogenic pathways, transcriptional changes, and epigenetic modifications. In this review, we aim to explore how dysregulated metabolic enzymes from the TCA cycle and oxidative phosphorylation, along with their metabolites, modulate both catabolic and anabolic metabolic pathways, as well as pro-oncogenic signaling pathways, transcriptional changes, and epigenetic modifications in GBM cells, contributing to the formation, survival, growth, and invasion of glioma cells. Additionally, we discuss promising therapeutic strategies targeting key players in metabolic regulation. Therefore, understanding metabolic reprogramming is necessary to fully comprehend the biology of malignant gliomas and significantly improve patient survival.

Targeting mitochondria: a novel approach for treating platinum-resistant ovarian cancer

Ovarian cancer is a prevalent gynecologic malignancy with the second-highest mortality rate among gynecologic malignancies. Platinum-based chemotherapy is the first-line treatment for ovarian cancer; however, a majority of patients with ovarian cancer experience relapse and develop platinum resistance following initial treatment. Despite extensive research on the mechanisms of platinum resistance at the nuclear level, the issue of platinum resistance in ovarian cancer remains largely unresolved. It is noteworthy that mitochondrial DNA (mtDNA) exhibits higher affinity for platinum compared to nuclear DNA (nDNA). Mutations in mtDNA can modulate tumor chemosensitivity through various mechanisms, including DNA damage responses, shifts in energy metabolism, maintenance of Reactive Oxygen Species (ROS) homeostasis, and alterations in mitochondrial dynamics. Concurrently, retrograde signals produced by mtDNA mutations and their subsequent cascades establish communication with the nucleus, leading to the reorganization of the nuclear transcriptome and governing the transcription of genes and signaling pathways associated with chemoresistance. Furthermore, mitochondrial translocation among cells emerges as a crucial factor influencing the effectiveness of chemotherapy in ovarian cancer. This review aims to explore the role and mechanism of mitochondria in platinum resistance, with a specific focus on mtDNA mutations and the resulting metabolic reprogramming, ROS regulation, changes in mitochondrial dynamics, mitochondria-nucleus communication, and mitochondrial transfer.

Bidirectional regulation of the cGAS-STING pathway in the immunosuppressive tumor microenvironment and its association with immunotherapy

Adaptive anti-tumor immunity is currently dependent on the natural immune system of the body. The emergence of tumor immunotherapy has improved prognosis and prolonged the survival cycle of patients. Current mainstream immunotherapies, including immune checkpoint blockade, chimeric antigen receptor T-cell immunotherapy, and monoclonal antibody therapy, are linked to natural immunity. The cGAS-STING pathway is an important natural immunity signaling pathway that plays an important role in fighting against the invasion of foreign pathogens and maintaining the homeostasis of the organism. Increasing evidence suggests that the cGAS-STING pathway plays a key role in tumor immunity, and the combination of STING-related agonists can significantly enhance the efficacy of immunotherapy and reduce the emergence of immunotherapeutic resistance. However, the cGAS-STING pathway is a double-edged sword, and its activation can enhance anti-tumor immunity and immunosuppression. Immunosuppressive cells, including M2 macrophages, MDSC, and regulatory T cells, in the tumor microenvironment play a crucial role in tumor escape, thereby affecting the immunotherapy effect. The cGAS-STING signaling pathway can bi-directionally regulate this group of immunosuppressive cells, and targeting this pathway can affect the function of immunosuppressive cells, providing new ideas for immunotherapy. In this study, we summarize the activation pathway of the cGAS-STING pathway and its immunological function and elaborate on the key role of this pathway in immune escape mediated by the tumor immunosuppressive microenvironment. Finally, we summarize the mainstream immunotherapeutic approaches related to this pathway and explore ways to improve them, thereby providing guidelines for further clinical services.

The movement of mitochondria in breast cancer: internal motility and intercellular transfer of mitochondria

As a major energy source for cells, mitochondria are involved in cell growth and proliferation, as well as migration, cell fate decisions, and many other aspects of cellular function. Once thought to be irreparably defective, mitochondrial function in cancer cells has found renewed interest, from suggested potential clinical biomarkers to mitochondria-targeting therapies. Here, we will focus on the effect of mitochondria movement on breast cancer progression. Mitochondria move both within the cell, such as to localize to areas of high energetic need, and between cells, where cells within the stroma have been shown to donate their mitochondria to breast cancer cells via multiple methods including tunneling nanotubes. The donation of mitochondria has been seen to increase the aggressiveness and chemoresistance of breast cancer cells, which has increased recent efforts to uncover the mechanisms of mitochondrial transfer. As metabolism and energetics are gaining attention as clinical targets, a better understanding of mitochondrial function and implications in cancer are required for developing effective, targeted therapeutics for cancer patients.

Cancer stem cells: advances in the glucose, lipid and amino acid metabolism

Cancer stem cells (CSCs) are a class of cells with self-renewal and multi-directional differentiation potential, which are present in most tumors, particularly in aggressive tumors, and perform a pivotal role in recurrence and metastasis and are expected to be one of the important targets for tumor therapy. Studies of tumor metabolism in recent years have found that the metabolic characteristics of CSCs are distinct from those of differentiated tumor cells, which are unique to CSCs and contribute to the maintenance of the stemness characteristics of CSCs. Moreover, these altered metabolic profiles can drive the transformation between CSCs and non-CSCs, implying that these metabolic alterations are important markers for CSCs to play their biological roles. The identification of metabolic changes in CSCs and their metabolic plasticity mechanisms may provide some new opportunities for tumor therapy. In this paper, we review the metabolism-related mechanisms of CSCs in order to provide a theoretical basis for their potential application in tumor therapy.

The evolutionary theory of cancer: challenges and potential solutions

The clonal evolution model of cancer was developed in the 1950s-1970s and became central to cancer biology in the twenty-first century, largely through studies of cancer genetics. Although it has proven its worth, its structure has been challenged by observations of phenotypic plasticity, non-genetic forms of inheritance, non-genetic determinants of clone fitness and non-tree-like transmission of genes. There is even confusion about the definition of a clone, which we aim to resolve. The performance and value of the clonal evolution model depends on the empirical extent to which evolutionary processes are involved in cancer, and on its theoretical ability to account for those evolutionary processes. Here, we identify limits in the theoretical performance of the clonal evolution model and provide solutions to overcome those limits. Although we do not claim that clonal evolution can explain everything about cancer, we show how many of the complexities that have been identified in the dynamics of cancer can be integrated into the model to improve our current understanding of cancer.

Beyond mitochondrial transfer, cell fusion rescues metabolic dysfunction and boosts malignancy in adenoid cystic carcinoma

Cancer cells with mitochondrial dysfunction can be rescued by cells in the tumor microenvironment. Using human adenoid cystic carcinoma cell lines and fibroblasts, we find that mitochondrial transfer occurs not only between human cells but also between human and mouse cells both in vitro and in vivo. Intriguingly, spontaneous cell fusion between cancer cells and fibroblasts could also emerge; specific chromosome loss might be essential for nucleus reorganization and the post-hybrid selection process. Both mitochondrial transfer through tunneling nanotubes (TNTs) and cell fusion "selectively" revive cancer cells, with mitochondrial dysfunction as a key motivator. Beyond mitochondrial transfer, cell fusion significantly enhances cancer malignancy and promotes epithelial-mesenchymal transition. Mechanistically, mitochondrial dysfunction in cancer cells causes L-lactate secretion to attract fibroblasts to extend TNTs and TMEM16F-mediated phosphatidylserine externalization, facilitating TNT formation and cell-membrane fusion. Our findings offer insights into mitochondrial transfer and cell fusion, highlighting potential cancer therapy targets.

Cell death and DNA damage via ROS mechanisms after applied antibiotics and antioxidants doses in prostate hyperplasia primary cell cultures

Tumor heterogeneity results in aggressive cancer phenotypes with acquired resistance. However, combining chemical treatment with adjuvant therapies that cause cellular structure and function perturbations may diminish the ability of cancer cells to resist at chemical treatment and lead to a less aggressive cancer phenotype. Applied treatments on prostate hyperplasia primary cell cultures exerted their antitumor activities through mechanisms including cell cycle blockage, oxidative stress, and cell death induction by flow cytometry methods. A 5.37 mM Chloramphenicol dose acts on prostate hyperplasia cells by increasing the pro-oxidant status, inducing apoptosis, autophagy, and DNA damage, but without ROS changes. Adding 6.30 mM vitamin C or 622 µM vitamin E as a supplement to 859.33 µM Chloramphenicol dose in prostate hyperplasia cells determines a significant increase of ROS level for a part of cells. However, other cells remain refractory to initial ROS, with significant changes in apoptosis, autophagy, and cell cycle arrest in G0/G1 or G2/M. When the dose of Chloramphenicol was increased to 5.37 mM for 6.30 mM of vitamin C, prostate hyperplasia cells reacted by ROS level drastically decreased, cell cycle arrest in G2/M, active apoptosis, and autophagy. The pro-oxidant action of 1.51 mM Erythromycin dose in prostate hyperplasia cell cultures induces changes in the apoptosis mechanisms and cell cycle arrest in G0/G1. Addition of 6.30 mM vitamin C to 1.51 mM Erythromycin dose in hyperplasia cell cultures, the pro-oxidant status determines diminished caspase 3/7 mechanism activation, but ROS level presents similar changes as Chloramphenicol dose and cell cycle arrest in G2/M. Flow cytometric analysis of cell death, oxidative stress, and cell cycle are recommended as laboratory techniques in therapeutic and diagnostic fields.

Cisplatin Resistance and Metabolism: Simplification of Complexity

Cisplatin is one of the most well-known anti-cancer drugs and has demonstrated efficacy against numerous tumor types for many decades. However, a key challenge with cisplatin, as with any chemotherapeutic agent, is the development of resistance with a resultant loss of efficacy. This resistance is often associated with metabolic alterations that allow insensitive cells to divide and survive under treatment. These adaptations could vary greatly among different tumor types and may seem questionable and incomprehensible at first glance. Here we discuss the disturbances in glucose, lipid, and amino acid metabolism in cisplatin-resistant cells as well as the roles of ferroptosis and autophagy in acquiring this type of drug intolerance.

Exploring the impact of flavin homeostasis on cancer cell metabolism

Flavins and their associated proteins have recently emerged as compelling players in the landscape of cancer biology. Flavins, encompassing flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), serve as coenzymes in a multitude of cellular processes, such as metabolism, apoptosis, and cell proliferation. Their involvement in oxidative phosphorylation, redox homeostasis, and enzymatic reactions has long been recognized. However, recent research has unveiled an extended role for flavins in the context of cancer. In parallel, riboflavin transporters (RFVTs), FAD synthase (FADS), and riboflavin kinase (RFK) have gained prominence in cancer research. These proteins, responsible for riboflavin uptake, FAD biosynthesis, and FMN generation, are integral components of the cellular machinery that governs flavin homeostasis. Dysregulation in the expression/function of these proteins has been associated with various cancers, underscoring their potential as diagnostic markers, therapeutic targets, and key determinants of cancer cell behavior. This review embarks on a comprehensive exploration of the multifaceted role of flavins and of the flavoproteins involved in nucleus-mitochondria crosstalk in cancer. We journey through the influence of flavins on cancer cell energetics, the modulation of RFVTs in malignant transformation, the diagnostic and prognostic significance of FADS, and the implications of RFK in drug resistance and apoptosis. This review also underscores the potential of these molecules and processes as targets for novel diagnostic and therapeutic strategies, offering new avenues for the battle against this relentless disease.

Mitochondrial Transfer as a Strategy for Enhancing Cancer Cell Fitness:Current Insights and Future Directions

It is now recognized that tumors are not merely masses of transformed cells but are intricately interconnected with healthy cells in the tumor microenvironment (TME), forming complex and heterogeneous structures. Recent studies discovered that cancer cells can steal mitochondria from healthy cells to empower themselves, while reducing the functions of their target organ. Mitochondrial transfer, i.e. the intercellular movement of mitochondria, is recently emerging as a novel process in cancer biology, contributing to tumor growth, metastasis, and resistance to therapy by shaping the metabolic landscape of the tumor microenvironment. This review highlights the influence of transferred mitochondria on cancer bioenergetics, redox balance and apoptotic resistance, which collectively foster aggressive cancer phenotype. Furthermore, the therapeutic implications of mitochondrial transfer are discussed, emphasizing the potential of targeting these pathways to overcome drug resistance and improve treatment efficacy.

A novel HMGA2/MPC-1/mTOR signaling pathway promotes cell growth via facilitating Cr (VI)-induced glycolysis

Mitochondrial Pyruvate Carrier 1 (MPC1) is localized on mitochondrial outer membrane to mediate the transport of pyruvate from cytosol to mitochondria. It is also well known to act as a tumor suppressor. Hexavalent chromium (Cr (VI)) contamination poses a global challenge due to its high toxicity and carcinogenesis. This research was intended to probe the potential mechanism of MPC1 in the effect of Cr (VI)-induced carcinogenesis. First, Cr (VI)-treatments decreased the expression of MPC1 in vitro and in vivo. Overexpression of MPC1 inhibited Cr (VI)-induced glycolysis and migration in A549 cells. Then, high mobility group A2 (HMGA2) protein strongly suppressed the transcription of MPC1 by binding to its promoter, and HMGA2/MPC1 axis played an important role in oxidative phosphorylation (OXPHOS), glycolysis and cell migration. Furthermore, endoplasmic reticulum (ER) stress made a great effect on the interaction between HMGA2 and MPC1. Finally, the mammalian target of the rapamycin (mTOR) was determined to mediate MPC1-regulated OXPHOS, aerobic glycolysis and cell migration. Collectively, our data revealed a novel HMGA2/MPC-1/mTOR signaling pathway to promote cell growth via facilitating the metabolism reprogramming from OXPHOS to aerobic glycolysis, which might be a potential therapy for cancers.

[Mitohormesis: a key driver of the therapy resistance in cancer cells]

A large body of literature highlights the importance of energy metabolism in the response of haematological malignancies to therapy. In this review, we are particularly interested in acute myeloid leukaemia, where mitochondrial metabolism plays a key role in response and resistance to treatment. We describe the new concept of mitohormesis in the response to therapy-induced stress and in the initiation of relapse in this disease.

Evolution and maintenance of mtDNA gene content across eukaryotes

Across eukaryotes, most genes required for mitochondrial function have been transferred to, or otherwise acquired by, the nucleus. Encoding genes in the nucleus has many advantages. So why do mitochondria retain any genes at all? Why does the set of mtDNA genes vary so much across different species? And how do species maintain functionality in the mtDNA genes they do retain? In this review, we will discuss some possible answers to these questions, attempting a broad perspective across eukaryotes. We hope to cover some interesting features which may be less familiar from the perspective of particular species, including the ubiquity of recombination outside bilaterian animals, encrypted chainmail-like mtDNA, single genes split over multiple mtDNA chromosomes, triparental inheritance, gene transfer by grafting, gain of mtDNA recombination factors, social networks of mitochondria, and the role of mtDNA dysfunction in feeding the world. We will discuss a unifying picture where organismal ecology and gene-specific features together influence whether organism X retains mtDNA gene Y, and where ecology and development together determine which strategies, importantly including recombination, are used to maintain the mtDNA genes that are retained.

Advances in the interaction of glycolytic reprogramming with lactylation

Lactylation is a novel post-translational modification (PTM) involving proteins that is induced by lactate accumulation. Histone lysine lactylation alters chromatin spatial configuration, influencing gene transcription and regulating the expression of associated genes. This modification plays a crucial role as an epigenetic regulatory factor in the progression of various diseases. Glycolytic reprogramming is one of the most extensively studied forms of metabolic reprogramming, recognized as a key hallmark of cancer cells. It is characterized by an increase in glycolysis and the inhibition of the tricarboxylic acid (TCA) cycle, accompanied by significant lactate production and accumulation. The two processes are closely linked by lactate, which interacts in various physiological and pathological processes. On the one hand, lactylation levels generally correlate positively with the extent of glycolytic reprogramming, being directly influenced by the lactate concentration produced during glycolytic reprogramming. On the other hand, lactylation can also regulate glycolytic pathways by affecting the transcription and structural functions of essential glycolytic enzymes. This review comprehensively outlines the mechanisms of lactylation and glycolytic reprogramming and their interactions in tumor progression, immunity, and inflammation, with the aim of elucidating the relationship between glycolytic reprogramming and lactylation.

To transfer mitochondria or not to transfer mitochondria: ADP does the trick

Horizontal mitochondrial transfer (HMT) has emerged as a novel phenomenon in cell biology, but it is unclear how this process of intercellular movement of mitochondria is regulated. A new study in PLOS Biology reports that ADP released by stressed cells is a signal that triggers HMT.