Targeting mitochondria metabolism for cancer therapy

Knockdown of NDUFAF6 inhibits breast cancer progression via promoting mitophagy and apoptosis

BACKGROUND

While NDUFAF6 is implicated in breast cancer, its specific role remains unclear.

METHODS

The expression levels and prognostic significance of NDUFAF6 in breast cancer were assessed using The Cancer Genome Atlas, Gene Expression Omnibus, Kaplan-Meier plotter and cBio-Portal databases. We knocked down NDUFAF6 in breast cancer cells using small interfering RNA and investigated its effects on cell proliferation and migration ability. We performed gene expression analysis and validated key findings using protein analysis. We also assessed mitochondrial activity and cellular metabolism.

RESULTS

NDUFAF6 was highly expressed in breast cancer, which was associated with a poorer prognosis. Knockdown of NDUFAF6 reduced the proliferation and migration ability of breast cancer cells. Transcriptome analysis revealed 2,101 differentially expressed genes enriched in apoptosis and mitochondrial signaling pathways. Western blot results showed NDUFAF6 knockdown enhanced apoptosis. In addition, differential gene enrichment analysis was related to mitochondrial signaling pathways, and western blot results verified that mitophagy was enhanced in NDUFAF6 knockdown breast cancer cells. JC-1 assay also showed that mitochondrial dysfunction and reactive oxygen species content were increased after knocking down NDUFAF6. In addition, basal and maximal mitochondrial oxygen consumption decreased, and intracellular glycogen content increased.

CONCLUSIONS

Knockdown of NDUFAF6 resulted in apoptosis and mitophagy in breast cancer cells and NDUFAF6 may be a potential molecular target for breast cancer therapy.

DNA or not DNA -that is the question determining the design of platinum anticancer drugs

Platinum drugs are the most widely used chemotherapeutics to treat various tumors. Their primary mode of action is supposed to be inducing apoptosis of cancer cells via covalent binding to DNA. This mechanism has shackled the design of new platinum drugs for many years. Mounting evidence shows that many platinum complexes form non-covalent adducts with DNA or interact with proteins to exhibit significant antitumor activity, thus implying some distinct mechanisms from that of traditional platinum drugs. These unconventional examples indicate that covalent DNA binding is not the precondition for the antitumor activity of platinum complexes, and diversified reactions or interactions with biomolecules, organelles, signal pathways, or immune system could lead to the antitumor activity of platinum complexes. The atypical mechanisms break the classical DNA-only paradigm and structure-activity relationships, thus opening a wide avenue for the design of innovative platinum anticancer drugs.

Mitochondrial mechanisms in Treg cell regulation: Implications for immunotherapy and disease treatment

Regulatory T cells (Tregs) play a critical role in maintaining immune homeostasis and preventing autoimmune diseases. Recent advances in immunometabolism have revealed the pivotal role of mitochondrial dynamics and metabolism in shaping Treg functionality. Tregs depend on oxidative phosphorylation (OXPHOS) and fatty acid oxidation (FAO) to support their suppressive functions and long-term survival. Mitochondrial processes such as fusion and fission significantly influence Treg activity, with mitochondrial fusion enhancing bioenergetic efficiency and reducing reactive oxygen species (ROS) production, thereby promoting Treg stability. In contrast, excessive mitochondrial fission disrupts ATP synthesis and elevates ROS levels, impairing Treg suppressive capacity. Furthermore, mitochondrial ROS act as critical signaling molecules in Treg regulation, where controlled levels stabilize FoxP3 expression, but excessive ROS leads to mitochondrial dysfunction and immune dysregulation. Mitophagy, as part of mitochondrial quality control, also plays an essential role in preserving Treg function. Understanding the intricate interplay between mitochondrial dynamics and Treg metabolism provides valuable insights for developing novel therapeutic strategies to treat autoimmune disorders and enhance immunotherapy in cancer.

Unraveling the intrinsic and photodynamic effects of aluminum chloride phthalocyanine on bioenergetics and oxidative state in rat liver mitochondria

Previous research has revealed that mitochondria are an important target for photodynamic therapy (PDT), which might be employed as a therapeutic approach for several malignancies, including hepatocellular carcinoma (HCC). In this study, we investigated both intrinsic toxicity and photodynamic effects of the photosensitizer (PS) aluminum chloride phthalocyanine (AlClPc) on mitochondrial functions. Several aspects of mitochondrial bioenergetics, structure, and oxidative state were investigated in the isolated mitochondria obtained from rat liver by differential centrifugation. Additionally, experiments were conducted to demonstrate the intrinsic and photodynamic effects of AlClPc on the viability of HepG2 cells. AlClPc interacted with mitochondria regardless of photostimulation; however, at the maximum utilized concentration (40 μM), photostimulation reduced its interaction with mitochondria. Although AlClPc hindered catalase (CAT) and glutathione reductase (GR) activities intrinsically, it had no discernable capacity to generate oxidative stress or impact bioenergetics in mitochondria without photostimulation, as one would anticipate from an ideal PS. When exposed to light, however, AlClPc had a substantially unfavorable influence on mitochondrial function, strengthening its intrinsic inhibitory action on CAT, producing oxidative stress, and jeopardizing mitochondrial bioenergetics. In terms of oxidative stress parameters, AlClPc induced lipid peroxidation and decreased the level of reduced glutathione (GSH) in mitochondria. Regarding bioenergetics, AlClPc promoted oxidative phosphorylation uncoupling and photodynamic inactivation of complex I, complex II, and the FoF1-ATP synthase complex, lowering mitochondrial ATP production. Lastly, AlClPc exhibited a concentration-dependent decrease in the viability of HepG2 cells, regardless of the presence or absence of photostimulation. While the harmful photodynamic effects of AlClPc on mitochondrial bioenergetics hold promise for treating HCC and other malignancies, the inherent toxic impacts on HepG2 cells underscore the need for caution in its application for this purpose.

Lysosome-Mitochondria Cascade Targeting Nanoparticle Drives Robust Pyroptosis for Cancer Immunotherapy

The subcellular distribution of cargoes plays a crucial role in determining cell fate and therapeutic efficacy. However, achieving the precise delivery of therapeutics to specific intracellular targets remains a significant challenge. Here, we present a trimodular and acid/enzyme-gated nanoplatform (TAEN) that undergoes disassembly within acidic endosomes and then is cleaved by lysosomal cathepsin B to facilitate efficient and targeted transport of released cargoes into mitochondria compartments. By utilizing this nanovehicle, we successfully achieve selective sorting of photosensitizer molecules into mitochondria with a colocalization coefficient of up to 0.98, leading to the generation of reactive oxygen species stress specifically within the mitochondria for potent pyroptosis-based cancer therapy. The induction of mitochondrial stress triggers the intrinsic apoptotic pathway as well as caspase-3/gasdermin-E (GSDME) cascade, resulting in an enhanced cancer cell killing efficacy by nearly 2 orders of magnitude as compared to lysosomal stress. Furthermore, due to its superior capability to stimulate both innate and adaptive immune responses, our mitochondria-sorted nanophotosensitizer exhibits robust antitumor immune efficacy in multiple tumor-bearing mice models. This study not only provides insights into engineering nanomedicines for subcellular targeted delivery but also offers a valuable toolkit for advanced research in the field of nanobiology at subcellular resolution.

ZNF143 is a transcriptional regulator of nuclear-encoded mitochondrial genes that acts independently of looping and CTCF

Gene expression is orchestrated by transcription factors, which function within the context of a three-dimensional genome. Zinc-finger protein 143 (ZNF143/ZFP143) is a transcription factor that has been implicated in both gene activation and chromatin looping. To study the direct consequences of ZNF143/ZFP143 loss, we generated a ZNF143/ZFP143 depletion system in mouse embryonic stem cells. Our results show that ZNF143/ZFP143 degradation has no effect on chromatin looping. Systematic analysis of ZNF143/ZFP143 occupancy data revealed that a commonly used antibody cross-reacts with CTCF, leading to its incorrect association with chromatin loops. Nevertheless, ZNF143/ZFP143 specifically activates nuclear-encoded mitochondrial genes, and its loss leads to severe mitochondrial dysfunction. Using an in vitro embryo model, we find that ZNF143/ZFP143 is an essential regulator of organismal development. Our results establish ZNF143/ZFP143 as a conserved transcriptional regulator of cell proliferation and differentiation by safeguarding mitochondrial activity.

Therapeutic types and advantages of functionalized nanoparticles in inducing ferroptosis in cancer therapy

BACKGROUND

The clinical efficacy of cancer treatment protocols remains unsatisfactory; however, the emergence of ferroptosis-driven therapy strategies has renewed hope for tumor treatment, owing to their remarkable tumor suppression effects. Biologically based small-molecule inducers are used in conventional method to induce ferroptosis. Nevertheless, some molecular drugs have limited solubility, poor ability to target cells, and fast metabolism, which hinder their ability to induce ferroptosis over a prolonged period. Fortunately, further investigations of ferroptosis and the development of nanotechnology have demonstrated that nanoparticles (NPs) are more efficient in inducing ferroptosis than drugs alone, which opens up new perspectives for cancer therapy.

OBJECTIVE

In order to organize a profile of recent advance in NPs for inducing ferroptosis in cancer therapy, and NPs were comprehensively classified in a new light.Materials and methods: We comprehensively searched the databases such as PubMed and Embase. The time limit for searching was from the establishment of the database to 2023.11. All literatures were related to "ferroptosis", "nanoparticles", "nanodelivery systems", "tumors", "cancer".

RESULTS

We summarized and classified the available NPs from a new perspective. The NPs were classified into six categories based on their properties: (1) iron oxide NPs (2) iron - based conversion NPs (3) core-shell structure (4) organic framework (5) silica NPs (6) lipoprotein NPs. According to the therapeutic types of NPs, they can be divided into categories: (1) NPs induced ferroptosis-related immunotherapy (2) NPs loaded with drugs (3) targeted therapy of NPs (4) multidrug resistance therapy (5) gene therapy with NPs (6) energy conversion therapy.

CONCLUSIONS

The insights gained from this review can provide ideas for the development of original NPs and nanodelivery systems, pave the way for related nanomaterials application in clinical cancer therapy, and advance the application and development of nanotechnology in the medical field.

Organelle-Specific Smart Supramolecular Materials for Bioimaging and Theranostics Application

In cellular environments, certain synthetic molecules can form nanostructures via self-assembly, impacting molecular imaging, and biomedical applications. Control over the formation of these self-assembled nanostructures in subcellular organelle is challenging. By the action of stimuli, either present in the cellular environment or applied externally, in situ generation of molecular precursors can lead to accumulation and supramolecular nanostructure formation, resulting in efficient bioimaging. Here, we summarize smart fluorophore-based ordered nanostructure preparation at specific organelles for efficient bioimaging and therapeutic application towards cancer theranostics. We also present challenges and an outlook regarding intercellular self-assembly for theranostics application. Altogether, smart nanostructured materials with fluorescence read-outs at specific subcellular compartments would be beneficial in synthetic biology and precision therapeutics.

Integrated analyses of multi-omic data derived from paired primary lung cancer and brain metastasis reveal the metabolic vulnerability as a novel therapeutic target

BACKGROUND

Lung cancer brain metastases (LC-BrMs) are frequently associated with dismal mortality rates in patients with lung cancer; however, standard of care therapies for LC-BrMs are still limited in their efficacy. A deep understanding of molecular mechanisms and tumor microenvironment of LC-BrMs will provide us with new insights into developing novel therapeutics for treating patients with LC-BrMs.

METHODS

Here, we performed integrated analyses of genomic, transcriptomic, proteomic, metabolomic, and single-cell RNA sequencing data which were derived from a total number of 154 patients with paired and unpaired primary lung cancer and LC-BrM, spanning four published and two newly generated patient cohorts on both bulk and single cell levels.

RESULTS

We uncovered that LC-BrMs exhibited a significantly greater intra-tumor heterogeneity. We also observed that mutations in a subset of genes were almost always shared by both primary lung cancers and LC-BrM lesions, including TTN, TP53, MUC16, LRP1B, RYR2, and EGFR. In addition, the genome-wide landscape of somatic copy number alterations was similar between primary lung cancers and LC-BrM lesions. Nevertheless, several regions of focal amplification were significantly enriched in LC-BrMs, including 5p15.33 and 20q13.33. Intriguingly, integrated analyses of transcriptomic, proteomic, and metabolomic data revealed mitochondrial-specific metabolism was activated but tumor immune microenvironment was suppressed in LC-BrMs. Subsequently, we validated our results by conducting real-time quantitative reverse transcription PCR experiments, immunohistochemistry, and multiplexed immunofluorescence staining of patients' paired tumor specimens. Therapeutically, targeting oxidative phosphorylation with gamitrinib in patient-derived organoids of LC-BrMs induced apoptosis and inhibited cell proliferation. The combination of gamitrinib plus anti-PD-1 immunotherapy significantly improved survival of mice bearing LC-BrMs. Patients with a higher expression of mitochondrial metabolism genes but a lower expression of immune genes in their LC-BrM lesions tended to have a worse survival outcome.

CONCLUSIONS

In conclusion, our findings not only provide comprehensive and integrated perspectives of molecular underpinnings of LC-BrMs but also contribute to the development of a potential, rationale-based combinatorial therapeutic strategy with the goal of translating it into clinical trials for patients with LC-BrMs.

Mitochondrial Dysfunction in Environmental Toxicology: Mechanisms, Impacts, and Health Implications

Mitochondria, pivotal to cellular metabolism, serve as the primary sources of biological energy and are key regulators of intracellular calcium ion storage, crucial for maintaining cellular calcium homeostasis. Dysfunction in these organelles impairs ATP synthesis, diminishing cellular functionality. Emerging evidence implicates mitochondrial dysfunction in the etiology and progression of diverse diseases. Environmental factors that induce mitochondrial dysregulation raise significant public health concerns, necessitating a nuanced comprehension and classification of mitochondrial-related hazards. This review systematically adopts a toxicological perspective to illuminate the biological functions of mitochondria, offering a comprehensive exploration of how toxicants instigate mitochondrial dysfunction. It delves into the disruption of energy metabolism, the initiation of mitochondrial fragility and autophagy, and the induction of mutations in mitochondrial DNA by mutagens. The overarching objective is to enhance our understanding of the repercussions of mitochondrial damage on human health.

Recent Advances in Silica-Based Nanomaterials for Enhanced Tumor Imaging and Therapy

Cancer remains a formidable challenge, inflicting profound physical, psychological, and financial burdens on patients. In this context, silica-based nanomaterials have garnered significant attention for their potential in tumor imaging and therapy owing to their exceptional properties, such as biocompatibility, customizable porosity, and versatile functionalization capabilities. This review meticulously examines the latest advancements in the application of silica-based nanomaterials for tumor imaging and therapy. It underscores their potential in enhancing various cancer imaging modalities, including fluorescence imaging, magnetic resonance imaging, computed tomography, positron emission tomography, ultrasound imaging, and multimodal imaging approaches. Moreover, the review delves into their therapeutic efficacy in chemotherapy, radiotherapy, phototherapy, immunotherapy, gas therapy, sonodynamic therapy, chemodynamic therapy, starvation therapy, and gene therapy. Critical evaluations of the biosafety profiles and degradation pathways of these nanomaterials within biological environments are also presented. By discussing the current challenges and prospects, this review aims to provide a nuanced perspective on the clinical translation of silica-based nanomaterials, thereby highlighting their promise in revolutionizing cancer diagnostics, enabling real-time monitoring of therapeutic responses, and advancing personalized medicine.

Spatial and Single-Cell Transcriptomics Unraveled Spatial Evolution of Papillary Thyroid Cancer

Recurrence and metastasis are the major issues for papillary thyroid cancer (PTC). Current morphological and molecular classification systems are not satisfied for PTC diagnosis due to lacking variant-specific morphological criteria and high signal-to-noise in mutation-based diagnosis, respectively. Importantly, intratumor heterogeneity is largely lost in current molecular classification system, which can be resolved by single cell RNA sequencing (scRNA-seq). However, scRNA-seq loses spatial information and morphological features. Herein, scRNA-seq is integrated and spatially-resolved transcriptomics (SRT) to elaborate the mechanisms underlying the spatial heterogeneity, malignancy and metastasis of PTCs by associating transcriptome and local morphology. This results demonstrated that PTC cells evolved with multiple routes, driven by the enhanced aerobic metabolism and the suppressed mRNA translation and protein synthesis and the involvement of cell-cell interaction. Two curated malignant and metastatic footprints can discriminate PTC cells from normal thyrocytes. Ferroptosis resistance contributed to PTC evolution. This results will advance the knowledge of intratumor spatial heterogeneity and evolution of PTCs at spatial and single-cell levels, and propose better diagnostic strategy.

PRMT1-mediated methylation of ME2 promotes hepatocellular carcinoma growth by inhibiting ubiquitination

The mitochondrial malic enzyme 2 (ME2), which is frequently elevated during carcinogenesis and may be a target for cancer therapy, catalyzes the conversion of malate to pyruvate. The processes controlling ME2 activity, however, remain largely unclear. In this work, we show that human hepatocellular carcinoma (HCC) tissues contain high levels of ME2 and that the methylation of ME2 stimulates the growth and migration of HCC cells. Furthermore, we observed that ME2 interacts with protein arginine methyltransferase 1 (PRMT1) and that ME2 enzymatic activity is activated by mutation of ME2 at lysine 67. Mitochondrial respiration was markedly increased by activated ME2, which promoted cell division and carcinogenesis. Furthermore, a negative prognosis for patients was strongly linked with the expression levels of PRMT1 and ME2 R67K in HCC tissues. These findings imply that hepatocellular carcinoma growth is aided by PRMT1-mediated ME2 methylation, that is an essential signaling event that cancer cells need to continue mitochondrial respiration.

LncRNA mediated metabolic reprogramming: the chief culprits of solid tumor malignant progression: an update review

Metabolism reprogramming (MR) is one of the top ten hallmarks of malignant tumors. The aberrant activation of MR has been recognized as a critical contributory factor to the malignant progression of solid tumors. Moreover, various long non-coding RNAs (lncRNAs) are implicated in the aberrant activation of MR in solid tumor cells. Therefore, in this review, we mainly focus on summarizing the functional relevance and molecular mechanistic underpinnings of lncRNAs in modulating MR of solid tumors by targeting glucose metabolism, lipid metabolism, affecting mitochondrial function, and regulating interactions between tumor and non-tumor cells in tumor microenvironment. Besides, we also underscore the potential for constructing lncRNAs-centered tumor metabolic regulation networks and developing novel anti-tumor strategies by targeting lncRNAs and abnormal MR. Ultimately, this review seeks to offer new targets and avenues for the clinical treatment of solid tumors in the future.

High mitochondrial DNA levels accelerate lung adenocarcinoma progression

Lung adenocarcinoma is a common aggressive cancer and a leading cause of mortality worldwide. Here, we report an important in vivo role for mitochondrial DNA (mtDNA) copy number during lung adenocarcinoma progression in the mouse. We found that lung tumors induced by KRASG12D expression have increased mtDNA levels and enhanced mitochondrial respiration. To experimentally assess a possible causative role in tumor progression, we induced lung cancer in transgenic mice with a general increase in mtDNA copy number and found that they developed a larger tumor burden, whereas mtDNA depletion in tumor cells reduced tumor growth. Immune cell populations in the lung and cytokine levels in plasma were not affected by increased mtDNA levels. Analyses of large cancer databases indicate that mtDNA copy number is also important in human lung cancer. Our study thus reports experimental evidence for a tumor-intrinsic causative role for mtDNA in lung cancer progression, which could be exploited for development of future cancer therapies.

Three-in-One: Molecular Engineering of D-A-π-A Featured Type I and Type II Near-Infrared AIE Photosensitizers for Efficient Photodynamic Cancer Therapy and Bacteria Killing

Bacterial infections are closely correlated with the genesis and progression of cancer, and the elimination of cancer-related bacteria may improve the efficacy of cancer treatment. However, the combinatorial therapy that utilizes two or more chemodrugs will increase potential adverse effects. Image-guided photodynamic therapy is a highly precise and potential therapy to treat tumor and microbial infections. Herein, four donor-acceptor-π-bridge-acceptor (D-A-π-A) featured near-infrared (NIR) aggregation-induced emission luminogens (AIEgens) (TQTPy, TPQTPy, TQTC, and TPQTC) with type I and type II reaction oxygen species (ROS) generation capabilities are synthesized. Notably, TQTPy shows mitochondria targeted capacity, the best ROS production efficiency, long-term tumor retention capacity, and more importantly, the three-in-one fluorescence imaging guided therapy against both tumor and microbial infections. Both in vitro and in vivo results validate that TQTPy performs well in practical biomedical application in terms of NIR-fluorescence imaging-guided photodynamic cancer diagnosis and treatment. Moreover, the amphiphilic and positively charged TQTPy is able to specific and ultrafast discrimination and elimination of Gram-positive (G+) Staphylococcus aureus from Gram-negative (G-) Escherichia coli and normal cells. This investigation provides an instructive way for the construction of three-in-one treatment for image-guided photodynamic cancer therapy and bacteria elimination.

Mitochondrial RelA empowers mtDNA G-quadruplex formation for hypoxia adaptation in cancer cells

Mitochondrial DNA (mtDNA) G-quadruplexes (G4s) have important regulatory roles in energy metabolism, yet their specific functions and underlying regulatory mechanisms have not been delineated. Using a chemical-genetic screening strategy, we demonstrated that the JAK/STAT3 pathway is the primary regulatory mechanism governing mtDNA G4 dynamics in hypoxic cancer cells. Further proteomic analysis showed that activation of the JAK/STAT3 pathway facilitates the translocation of RelA, a member of the NF-κB family, to the mitochondria, where RelA binds to mtDNA G4s and promotes their folding, resulting in increased mtDNA instability, inhibited mtDNA transcription, and subsequent mitochondrial dysfunction. This binding event disrupts the equilibrium of energy metabolism, catalyzing a metabolic shift favoring glycolysis. Collectively, the results provide insights into a strategy employed by cancer cells to adapt to hypoxia through metabolic reprogramming.

Identification of the metabolic protein ATP5MF as a potential therapeutic target of TNBC

BACKGROUND

Triple-negative breast cancer (TNBC), a distinct subtype of breast cancer, is characterized by its high invasiveness, high metastatic potential, proneness to relapse, and poor prognosis. Effective treatment regimens for non-BRCA1/2 mutation TNBC are still lacking. As a result, there is a pressing clinical necessity to develop novel treatment approaches for non-BRCA1/2 mutation TNBC.

METHODS

For this research, the scRNA data was obtained from the GEO database, while the transcriptome data was obtained from the TCGA and METABRIC databases. Quality control procedures were conducted on single-cell sequencing data. and then annotation and the Copycat algorithm were applied for anlysis. Employing the high dimensional weighted gene coexpression network analysis (hdWGCNA) method, we analyzed the tumor epithelial cells from non-BRCA1/2 mutation TNBC to identify the functional module genes. PPI analysis and survival analysis were further emplyed to identify the key gene. siRNA-NC and siRNA-ATP5MF were transfected into two MDA-MB-231 and BT-549 TNBC cell lines. Cell growth was determined by CCK8 assay, colony formation and migration assay. Electron microscopy was used to examine the structure of mitochondria in cells. JC-1 staining was used to measure the potential of the mitochondrial membrane. A tumor xenograft animal model was established by injecting TNBC cells into nude mice. The animal model was usded to evaluated in vivo tumor response aftering ATP5MF silencing.

RESULTS

Using hdWGCNA, we have identified 136 genes in module 3. After PPI and survival analysis, we have identified ATP5MF as a potential therapeutic gene. High ATP5MF expression was associated with poor prognosis of non-BRCA1/2 mutation TNBC. The high expression of ATP5MF in TNBC tissues was evaluated using the TCGA database and IHC staining of clinical TNBC specimens. Silencing ATP5MF in two TNBC cell lines reduced the growth and colony formation of TNBC cells in vitro, and hindered the growth of TNBC xenografts in vivo. Additionally, ATP5MF knockdown impaired mitochondrial functions in TNBC cells.

CONCLUSION

In summary, the metabolic protein ATP5MF plays a crucial role in the non-BRCA1/2 mutation TNBC cells, making it a potential novel diagnostic and therapeutic oncotarget for non-BRCA1/2 mutation TNBC.

Insights into the anticancer photodynamic activity of Ir(III) and Ru(II) polypyridyl complexes bearing β-carboline ligands

Ir(III) and Ru(II) polypyridyl complexes are promising photosensitizers (PSs) for photodynamic therapy (PDT) due to their outstanding photophysical properties. Herein, one series of cyclometallated Ir(III) complexes and two series of Ru(II) polypyridyl derivatives bearing three different thiazolyl-β-carboline N^N' ligands have been synthesized, aiming to evaluate the impact of the different metal fragments ([Ir(C^N)2]+ or [Ru(N^N)2]2+) and N^N' ligands on the photophysical and biological properties. All the compounds exhibit remarkable photostability under blue-light irradiation and are emissive (605 < λem < 720 nm), with the Ru(II) derivatives displaying higher photoluminescence quantum yields and longer excited state lifetimes. The Ir PSs display pKa values between 5.9 and 7.9, whereas their Ru counterparts are less acidic (pKa > 9.3). The presence of the deprotonated form in the Ir-PSs favours the generation of reactive oxygen species (ROS) since, according to theoretical calculations, it features a low-lying ligand-centered triplet excited state (T1 = 3LC) with a long lifetime. All compounds have demonstrated anticancer activity. Ir(III) complexes 1-3 exhibit the highest cytotoxicity in dark conditions, comparable to cisplatin. Their activity is notably enhanced by blue-light irradiation, resulting in nanomolar IC50 values and phototoxicity indexes (PIs) between 70 and 201 in different cancer cell lines. The Ir(III) PSs are also activated by green (with PI between 16 and 19.2) and red light in the case of complex 3 (PI = 8.5). Their antitumor efficacy is confirmed by clonogenic assays and using spheroid models. The Ir(III) complexes rapidly enter cells, accumulating in mitochondria and lysosomes. Upon photoactivation, they generate ROS, leading to mitochondrial dysfunction and lysosomal damage and ultimately cell apoptosis. Additionally, they inhibit cancer cell migration, a crucial step in metastasis. In contrast, Ru(II) complex 6 exhibits moderate mitochondrial activity. Overall, Ir(III) complexes 1-3 show potential for selective light-controlled cancer treatment, providing an alternative mechanism to chemotherapy and the ability to inhibit lethal cancer cell dissemination.

F-ATP synthase inhibitory factor 1 and mitochondria-organelle interactions: New insight and implications

Mitochondria are metabolic hub, and act as primary sites for reactive oxygen species (ROS) and metabolites generation. Mitochondrial Ca2+ uptake contributes to Ca2+ storage. Mitochondria-organelle interactions are important for cellular metabolic adaptation, biosynthesis, redox balance, cell fate. Organelle communications are mediated by Ca2+/ROS signals, vesicle transport and membrane contact sites. The permeability transition pore (PTP) is an unselective channel that provides a release pathway for Ca2+/ROS, mtDNA and metabolites. F-ATP synthase inhibitory factor 1 (IF1) participates in regulation of PTP opening and is required for the translocation of transcriptional factors c-Myc/PGC1α to mitochondria to stimulate metabolic switch. IF1, a mitochondrial specific protein, has been suggested to regulate other organelles including nucleus, endoplasmic reticulum and lysosomes. IF1 may be able to mediate mitochondria-organelle interactions and cellular physiology through regulation of PTP activity.

Treg Cell Therapeutic Strategies for Breast Cancer: Holistic to Local Aspects

Regulatory T cells (Tregs) play a key role in maintaining immune homeostasis and preventing autoimmunity through their immunosuppressive function. There have been numerous reports confirming that high levels of Tregs in the tumor microenvironment (TME) are associated with a poor prognosis, highlighting their role in promoting an immunosuppressive environment. In breast cancer (BC), Tregs interact with cancer cells, ultimately leading to the suppression of immune surveillance and promoting tumor progression. This review discusses the dual role of Tregs in breast cancer, and explores the controversies and therapeutic potential associated with targeting these cells. Researchers are investigating various strategies to deplete or inhibit Tregs, such as immune checkpoint inhibitors, cytokine antagonists, and metabolic inhibition. However, the heterogeneity of Tregs and the variable precision of treatments pose significant challenges. Understanding the functional diversity of Tregs and the latest advances in targeted therapies is critical for the development of effective therapies. This review highlights the latest approaches to Tregs for BC treatment that both attenuate Treg-mediated immunosuppression in tumors and maintain immune tolerance, and advocates precise combination therapy strategies to optimize breast cancer outcomes.

Mitochondrial reprogramming by activating OXPHOS via glutamine metabolism in African American patients with bladder cancer

Bladder cancer (BLCA) mortality is higher in African American (AA) patients compared with European American (EA) patients, but the molecular mechanism underlying race-specific differences are unknown. To address this gap, we conducted comprehensive RNA-Seq, proteomics, and metabolomics analysis of BLCA tumors from AA and EA. Our findings reveal a distinct metabolic phenotype in AA BLCA characterized by elevated mitochondrial oxidative phosphorylation (OXPHOS), particularly through the activation of complex I. The results provide insight into the complex I activation-driven higher OXPHOS activity resulting in glutamine-mediated metabolic rewiring and increased disease progression, which was also confirmed by [U]13C-glutamine tracing. Mechanistic studies further demonstrate that knockdown of NDUFB8, one of the components of complex I in AA BLCA cells, resulted in reduced basal respiration, ATP production, GLS1 expression, and proliferation. Moreover, preclinical studies demonstrate the therapeutic potential of targeting complex I, as evidenced by decreased tumor growth in NDUFB8-depleted AA BLCA tumors. Additionally, genetic and pharmacological inhibition of GLS1 attenuated mitochondrial respiration rates and tumor growth potential in AA BLCA. Taken together, these findings provide insight into BLCA disparity for targeting GLS1-Complex I for future therapy.

Comparison of Mitochondrial and Antineoplastic Effects of Amiodarone and Desethylamiodarone in MDA-MB-231 Cancer Line

Previously, we have demonstrated that amiodarone (AM), a widely used antiarrhythmic drug, and its major metabolite desethylamiodarone (DEA) both affect several mitochondrial processes in isolated heart and liver mitochondria. Also, we have established DEA's antitumor properties in various cancer cell lines and in a rodent metastasis model. In the present study, we compared AM's and DEA's mitochondrial and antineoplastic effects in a human triple-negative breast cancer (TNBC) cell line. Both compounds reduced viability in monolayer and sphere cultures and the invasive growth of the MDA-MB-231 TNBC line by inducing apoptosis. They lowered mitochondrial trans-membrane potential, increased Ca2+ influx, induced mitochondrial permeability transition, and promoted mitochondrial fragmentation. In accordance with their mitochondrial effects, both substances massively decreased overall, and even to a greater extent, mitochondrial ATP production decreased, as determined using a Seahorse live cell respirometer. In all these effects, DEA was more effective than AM, indicating that DEA may have higher potential in the therapy of TNBC than its parent compound.

Cytotoxic properties, glycolytic effects and high-resolution respirometry mitochondrial activities of Eriocephalus racemosus against MDA-MB 231 triple-negative breast cancer

INTRODUCTION

Triple-negative breast cancer (TNBC) represents a significant global health crisis due to its resistance to conventional therapies and lack of specific molecular targets. This study explored the potential of Eriocephalus racemosus (E. racemosus) as an alternative treatment for TNBC. The cytotoxic properties and high-resolution respirometry mitochondrial activities of E. racemosus against the MDA-MB 231 TNBC cell line were evaluated.

METHODS

Hexane solvent and bioactive fraction extractions of E. racemosus were performed, while mass spectrometry-based metabolite profiling was used to identify the phytochemical constituents of the extracts. The extracts were further tested against MDA-MB 231 TNBC cells to determine their cytotoxicity. The mode of cell death was determined using flow cytometry. The activities of caspases 3, 8, and 9 were assessed using a multiplex activity assay kit. Glycolytic activity and High-resolution respirometry measurements of mitochondrial function in the MDA-MB 231 cell line were conducted using the Seahorse XFp and Oroboros O2K.

RESULTS

Metabolite profiling of E. racemosus plant crude extracts identified the presence of coumarins, flavonoids, sesquiterpenoids, triterpenoids, and unknown compounds. The extracts demonstrated promising cytotoxic activities, with a half maximal inhibitory concentration (IC50) of 12.84 µg/mL for the crude hexane extract and 15.49 µg/mL for the bioactive fraction. Further, the crude hexane and bioactive fraction extracts induced apoptosis in the MDA-MB-231 TNBC cells, like the reference drug cisplatin (17.44%, 17.26% and 20.25%, respectively) compared to untreated cells. Caspase 3 activities confirmed the induction of apoptosis in both cisplatin and the plant crude extracts, while caspase 8 and 9 activities confirmed the activation of both the intrinsic and extrinsic apoptosis pathways. Increased levels of glycolytic activity were observed in the hexane crude extract. High-resolution respiratory measurements showed elevated mitochondrial activities in all mitochondrial states except for complex-IV activity.

CONCLUSION

These findings support further exploration of E. racemosus as a potential therapeutic agent for TNBC, offering a promising avenue for the development of targeted treatments with minimal adverse effects.

SMYD2 induced PGC1α methylation promotes stemness maintenance of glioblastoma stem cells

BACKGROUND

The high fatality rate of glioblastoma (GBM) is attributed to glioblastoma stem cells (GSCs), which exhibit heterogeneity and therapeutic resistance. Metabolic plasticity of mitochondria is the hallmark of GSCs. Targeting mitochondrial biogenesis of GSCs is crucial for improving clinical prognosis in GBM patients.

METHODS

SMYD2-induced PGC1α methylation and followed nuclear export are confirmed by co-immunoprecipitation, cellular fractionation, and immunofluorescence. The effects of SMYD2/PGC1α/CRM1 axis on GSCs mitochondrial biogenesis are validated by oxygen consumption rate, ECAR, and intracranial glioma model.

RESULTS

PGC1α methylation causes the disabled mitochondrial function to maintain the stemness, thereby enhancing the radio-resistance of GSCs. SMYD2 drives PGC1α K224 methylation (K224me), which is essential for promoting the stem-like characteristics of GSCs. PGC1α K224me is preferred binding with CRM1, accelerating PGC1α nuclear export and subsequent dysfunction. Targeting PGC1α methylation exhibits significant radiotherapeutic efficacy and prolongs patient survival.

CONCLUSIONS

These findings unveil a novel regulatory pathway involving mitochondria that govern stemness in GSCs, thereby emphasizing promising therapeutic strategies targeting PGC1α and mitochondria for the treatment of GBM.

DNA Nanotechnology Targeting Mitochondria: From Subcellular Molecular Imaging to Tailor-Made Therapeutics

Mitochondria, one of the most important organelles, represent a crucial subcellular target for fundamental research and biomedical applications. Despite significant advances in the design of DNA nanotechnologies for a variety of bio-applications, the dearth of strategies that enable mitochondria targeting for subcellular molecular imaging and therapy remains an outstanding challenge in this field. In this Minireview, we summarize the recent progresses on the emerging design and application of DNA nanotechnology for mitochondria-targeted molecular imaging and tumor treatment. We first highlight the engineering of mitochondria-localized DNA nanosensors for in situ detection and imaging of diverse key molecules that are essential to maintain mitochondrial functions, including mitochondrial DNA and microRNA, enzymes, small molecules, and metal ions. Then, we compile the developments of DNA nanotechnologies for mitochondria-targeted anti-tumor therapy, including modularly designed DNA nanodevices for subcellular delivery of therapeutic agents, and programmed DNA assembly for mitochondrial interference. We will place an emphasis on clarification of the chemical principles of how DNA nanobiotechnology can be designed to target mitochondria for various biomedical applications. Finally, the remaining challenges and future directions in this emerging field will be discussed, hoping to inspire further development of advanced DNA toolkits for both academic and clinical research regarding mitochondria.

Current status and trend of mitochondrial research in lung cancer: A bibliometric and visualization analysis

This study summarizes and analyzes the relationship between mitochondria and the pathogenesis of lung cancer. The related articles in the Web of Science core literature database are searched and collected, and the data are processed by R software, Citespace, VOSviewer, and Excel. A total of 4476 related papers were retrieved, 4476 articles from 20162 co-authors of 3968 institutions in 84 countries and published in 951 journals. Through various bibliometric analysis tools, the relationship between mitochondria and the pathogenesis of lung cancer was analyzed, the previous research results were summarized, and the potential research direction was found.

Discovery of NFκB2-Coordinated Dual Regulation of Mitochondrial and Nuclear Genomes Leads to an Effective Therapy for Acute Myeloid Leukemia

Acute myeloid leukemia (AML) has a poor survival rate for both pediatric and adult patients due to its frequent relapse. To elucidate the bioenergetic principle underlying AML relapse, we investigated the transcriptional regulation of mitochondrial-nuclear dual genomes responsible for metabolic plasticity in treatment-resistant blasts. Both the gain and loss of function results demonstrated that NFκB2, a noncanonical transcription factor (TF) of the NFκB (nuclear factor kappa-light-chain-enhancer of activated B cells) family, can control the expression of TFAM (mitochondrial transcription factor A), which is known to be essential for metabolic biogenesis. Furthermore, genetic tracking and promoter assays revealed that NFκB2 is in the mitochondria and can bind the specific "TTGGGGGGTG" region of the regulatory D-loop domain to activate the light-strand promoter (LSP) and heavy-strand promoter 1 (HSP1), promoters of the mitochondrial genome. Based on our discovery of NFκB2's novel function of regulating mitochondrial-nuclear dual genomes, we explored a novel triplet therapy including inhibitors of NFκB2, tyrosine kinase, and mitochondrial ATP synthase that effectively eliminated primary AML blasts with mutations of the FMS-related receptor tyrosine kinase 3 (FLT3) and displayed minimum toxicity to control cells ex vivo. As such, effective treatments for AML must include strong inhibitory actions on the dual genomes mediating metabolic plasticity to improve leukemia prognosis.

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.

An Intramolecular Rotor-Bridged Dimeric Cyanine Photothermal Transducer for Efficient Near-Infrared II Fluorescence Imaging-Guided Mitochondria-Targeted Phototherapy

Near-infrared (NIR) heptamethine cyanine (HCy) dyes are promising photothermal transducers for image-guided cancer treatment owing to their prominent photophysical properties and high photothermal conversion ability. However, HCy photothermal transducers usually have poor photostability due to degradation induced by the self-generated reactive oxygen species. Herein, a novel mitochondria-targeting dimeric HCy dye, named dimeric oBHCy, is rationally designed, exhibiting strong near-infrared II (NIR-II) fluorescence emission, high photothermal conversion efficiency (PCE), and excellent photostability. The large π-conjugation and drastic intramolecular motion of the diphenol rotor in the dimeric oBHCy enhance the nonradiative energy dissipation and suppress the intersystem crossing process, thereby achieving a high PCE (49.2%) and improved photostability. Impressively, dimeric oBHCy can precisely target mitochondria and induce mitochondrial damage upon NIR light irradiation. Under the guidance of in vivo NIR-II fluorescence imaging, efficient NIR light-activated photothermal therapy of 4T1 breast tumors is accomplished with a tumor inhibitory rate of 96% following a single injection of the dimeric oBHCy. This work offers an innovative strategy for designing cyanine photothermal transducers with integrated NIR-II fluorescence and photothermal properties for efficient cancer theranostics.

A Ketogenic Diet Sensitizes Pancreatic Cancer to Inhibition of Glutamine Metabolism

Pancreatic cancer is the third leading cause of cancer death in the United States, and while conventional chemotherapy remains the standard treatment, responses are poor. Safe and alternative therapeutic strategies are urgently needed 1 . A ketogenic diet has been shown to have anti-tumor effects across diverse cancer types but will unlikely have a significant effect alone. However, the diet shifts metabolism in tumors to create new vulnerabilities that can be targeted (1). Modulators of glutamine metabolism have shown promise in pre-clinical models but have failed to have a marked impact against cancer in the clinic. We show that a ketogenic diet increases TCA and glutamine-associated metabolites in murine pancreatic cancer models and under metabolic conditions that simulate a ketogenic diet in vitro. The metabolic shift leads to increased reliance on glutamine-mediated anaplerosis to compensate for low glucose abundance associated with a ketogenic diet. As a result, glutamine metabolism inhibitors, such as DON and CB839 in combination with a ketogenic diet had robust anti-cancer effects. These findings provide rationale to study the use of a ketogenic diet with glutamine targeted therapies in a clinical context.

Molecular Mechanisms of Anticarcinogenic Potential of Hydrocotyle umbellata and Its Major Components

Despite the development of several anticancer treatments, there remains a need for new drugs that can overcome resistance and reduce side effects. While the medicinal herb Hydrocotyle umbellata (H. umbellata) has been used to relieve pain and inflammation, its antitumor properties have not yet been explored. In this study, we investigated the anticarcinogenic potential of H. umbellata extract (HUE) and its major components, as well as the underlying molecular mechanisms. Our results showed that HUE inhibited the growth of various tumor cell lines, including B16F10, without affecting non-cancer cells. Furthermore, HUE was effective in treating and preventing tumor growth in mice. Our mechanistic studies revealed that HUE inhibited cellular respiration, thereby reducing tumor cell proliferation. When combined with 2-deoxy-D-glucose, HUE demonstrated an enhanced anticancer effect by increasing the rate apoptosis. Analysis of the ethyl acetate and n-butanol fractions of HUE identified 1,3,4-trihydroxy-2-butanyl-α-d-glucopyranoside and caffeoylquinic acid derivatives as the major components responsible for the observed anticancer effects. In conclusion, our findings suggest that HUE and its two major components have the potential to be developed as effective therapeutic agents for a wide range of tumors by targeting cancer cell metabolism.

Metabolic pathway-based subtyping reveals distinct microenvironmental states associated with diffuse large B-cell lymphoma outcomes

Diffuse large B-cell lymphoma (DLBCL) is a biologically and clinically heterogeneous disease that requires personalized clinical treatment. Assigning patients to different risk categories and cytogenetic abnormality and genetic mutation groups has been widely applied for prognostic stratification of DLBCL. Increasing evidence has demonstrated that dysregulated metabolic processes contribute to the initiation and progression of DLBCL. Metabolic competition within the tumor microenvironment is also known to influence immune cell metabolism. However, metabolism- and immune-related stratification has not been established. Here, 1660 genes involved in 84 metabolic pathways were selected and tested to establish metabolic clusters (MECs) of DLBCL. MECs established based on independent lymphoma datasets distinguished different survival outcomes. The CIBERSORT algorithm and EcoTyper were applied to quantify the relative abundance of immune cell types and identify variation in cell states for 13 lineages comprising the tumor micro environment among different MECs, respectively. Functional characterization showed that MECs were an indicator of the immune microenvironment and correlated with distinctive mutational characteristics and oncogenic signaling pathways. The novel immune-related MECs exhibited promising clinical prognostic value and potential for informing DLBCL treatment decisions.

Decoding mitochondria's role in immunity and cancer therapy

The functions of mitochondria, including energy production and biomolecule synthesis, have been known for a long time. Given the rising incidence of cancer, the role of mitochondria in cancer has become increasingly popular. Activated by components released by mitochondria, various pathways interact with each other to induce immune responses to protect organisms from attack. However, mitochondria play dual roles in the progression of cancer. Abnormalities in proteins, which are the elementary structures of mitochondria, are closely linked with oncogenesis. Both the aberrant accumulation of intermediates and mutations in enzymes result in the generation and progression of cancer. Therefore, targeting mitochondria to treat cancer may be a new strategy. Several drugs aimed at inhibiting mutated enzymes and accumulated intermediates have been tested clinically. Here, we discuss the current understanding of mitochondria in cancer and the interactions between mitochondrial functions, immune responses, and oncogenesis. Furthermore, we discuss mitochondria as hopeful targets for cancer therapy, providing insights into the progression of future therapeutic strategies.

Our current understanding of the biological impact of endometrial cancer mtDNA genome mutations and their potential use as a biomarker

Endometrial cancer (EC) is a devastating and common disease affecting women's health. The NCI Surveillance, Epidemiology, and End Results Program predicted that there would be >66,000 new cases in the United States and >13,000 deaths from EC in 2023, and EC is the sixth most common cancer among women worldwide. Regulation of mitochondrial metabolism plays a role in tumorigenesis. In proliferating cancer cells, mitochondria provide the necessary building blocks for biosynthesis of amino acids, lipids, nucleotides, and glucose. One mechanism causing altered mitochondrial activity is mitochondrial DNA (mtDNA) mutation. The polyploid human mtDNA genome is a circular double-stranded molecule essential to vertebrate life that harbors genes critical for oxidative phosphorylation plus mitochondrial-derived peptide genes. Cancer cells display aerobic glycolysis, known as the Warburg effect, which arises from the needs of fast-dividing cells and is characterized by increased glucose uptake and conversion of glucose to lactate. Solid tumors often contain at least one mtDNA substitution. Furthermore, it is common for cancer cells to harbor mixtures of wild-type and mutant mtDNA genotypes, known as heteroplasmy. Considering the increase in cancer cell energy demand, the presence of functionally relevant carcinogenesis-inducing or environment-adapting mtDNA mutations in cancer seems plausible. We review 279 EC tumor-specific mtDNA single nucleotide variants from 111 individuals from different studies. Many transition mutations indicative of error-prone DNA polymerase γ replication and C to U deamination events were present. We examine the spectrum of mutations and their heteroplasmy and discuss the potential biological impact of recurrent, non-synonymous, insertion, and deletion mutations. Lastly, we explore current EC treatments, exploiting cancer cell mitochondria for therapy and the prospect of using mtDNA variants as an EC biomarker.

Anticancer activity of 8-hydroxyquinoline-triphenylphosphine rhodium(III) complexes targeting mitophagy pathways

Metallodrugs exhibiting distinct mechanisms of action compared with cisplatin hold promise for overcoming cisplatin resistance and improving the efficacy of anticancer drugs. In this study, a new series of rhodium (Rh)(III) complexes containing tris(triphenylphosphine)rhodium(I) chloride [(TPP)3RhCl] (TPP = triphenylphosphine, TPP=O = triphenylphosphine oxide) and 8-hydroxyquinoline derivatives (H-XR1-H-XR4), namely [Rh(XR1)2(TPP)Cl]·(TPP=O) (Yulin Normal University-1a [YNU-1a]), [Rh(XR2)2(TPP)Cl] (YNU-1b), [Rh(XR3)2(TPP)Cl] (YNU-1c), and [Rh(XR4)2(TPP)Cl] (YNU-1d), was synthesized and characterized via X-ray diffraction, mass spectrometry and IR. The cytotoxicity of the compounds YNU-1a-YNU-1d in Hep-G2 and HCC1806 human cancer cell lines and normal HL-7702 cell line was evaluated. YNU-1c exhibited cytotoxicity and selectivity in HCC1806 cells (IC50 = 0.13 ± 0.06 μM, selectivity factor (SF) = 384.6). The compounds YNU-1b and YNU-1c, which were selected for mechanistic studies, induced the activation of apoptotic pathways and mitophagy. In addition, these compounds released cytochrome c, cleaved caspase-3/pro-caspase-3 and downregulated the levels of mitochondrial respiratory chain complexes I/IV (M1 and M4) and ATP. The compound YNU-1c, which was selected for in vivo experiments, exhibited tumor growth inhibition (58.9 %). Importantly, hematoxylin and eosin staining and TUNEL revealed that HCC1806 tumor tissues exhibited significant apoptotic characteristics. YNU-1a-YNU-1d compounds are promising drug candidates that can be used to overcome cisplatin resistance.

Suppressing mitochondrial inner membrane protein (IMMT) inhibits the proliferation of breast cancer cells through mitochondrial remodeling and metabolic regulation

Metabolic reprogramming is widely recognized as a hallmark of malignant tumors, and the targeting of metabolism has emerged as an appealing approach for cancer treatment. Mitochondria, as pivotal organelles, play a crucial role in the metabolic regulation of tumor cells, and their morphological and functional alterations are intricately linked to the biological characteristics of tumors. As a key regulatory subunit of mitochondria, mitochondrial inner membrane protein (IMMT), plays a vital role in degenerative diseases, but its role in tumor is almost unknown. The objective of this research was to investigate the roles that IMMT play in the development and progression of breast cancer (BC), as well as to elucidate the underlying biological mechanisms that drive these effects. In this study, it was confirmed that the expression of IMMT in BC tissues was significantly higher than that in normal tissues. The analysis of The Cancer Genome Atlas (TCGA) database revealed that IMMT can serve as an independent prognostic factor for BC patients. Additionally, verification in clinical specimens of BC demonstrated a positive association between high IMMT expression and larger tumor size (> 2 cm), Ki-67 expression (> 15%), and HER-2 status. Furthermore, in vitro experiments have substantiated that the suppression of IMMT expression resulted in a reduction in cell proliferation and alterations in mitochondrial cristae, concomitant with the liberation of cytochrome c, but it did not elicit mitochondrial apoptosis. Through Gene Set Enrichment Analysis (GSEA) analysis, we have predicted the associated metabolic genes and discovered that IMMT potentially modulates the advancement of BC through its interaction with 16 metabolic-related genes, and the changes in glycolysis related pathways have been validated in BC cell lines after IMMT inhibition. Consequently, this investigation furnishes compelling evidence supporting the classification of IMMT as prognostic marker in BC, and underscoring its prospective utility as a novel target for metabolic therapy.

RESPIRATION DEFECTS LIMIT SERINE SYNTHESIS REQUIRED FOR LUNG CANCER GROWTH AND SURVIVAL

Mitochondrial function is important for both energetic and anabolic metabolism. Pathogenic mitochondrial DNA (mtDNA) mutations directly impact these functions, resulting in the detrimental consequences seen in human mitochondrial diseases. The role of pathogenic mtDNA mutations in human cancers is less clear; while pathogenic mtDNA mutations are observed in some cancer types, they are almost absent in others. We report here that the proofreading mutant DNA polymerase gamma ( PolG D256A ) induced a high mtDNA mutation burden in non-small-cell lung cancer (NSCLC), and promoted the accumulation of defective mitochondria, which is responsible for decreased tumor cell proliferation and viability and increased cancer survival. In NSCLC cells, pathogenic mtDNA mutations increased glycolysis and caused dependence on glucose. The glucose dependency sustained mitochondrial energetics but at the cost of a decreased NAD+/NADH ratio that inhibited de novo serine synthesis. Insufficient serine synthesis, in turn, impaired the downstream synthesis of GSH and nucleotides, leading to impaired tumor growth that increased cancer survival. Unlike tumors with intact mitochondrial function, NSCLC with pathogenic mtDNA mutations were sensitive to dietary serine and glycine deprivation. Thus, mitochondrial function in NSCLC is required specifically to sustain sufficient serine synthesis for nucleotide production and redox homeostasis to support tumor growth, explaining why these cancers preserve functional mtDNA.

In brief

High mtDNA mutation burden in non-small-cell lung cancer (NSCLC) leads to the accumulation of respiration-defective mitochondria and dependency on glucose and glycolytic metabolism. Defective respiratory metabolism causes a massive accumulation of cytosolic nicotinamide adenine dinucleotide + hydrogen (NADH), which impedes serine synthesis and, thereby, glutathione (GSH) and nucleotide synthesis, leading to impaired tumor growth and increased survival.

Highlights

Proofreading mutations in Polymerase gamma led to a high burden of mitochondrial DNA mutations, promoting the accumulation of mitochondria with respiratory defects in NSCLC.Defective respiration led to reduced proliferation and viability of NSCLC cells increasing survival to cancer.Defective respiration caused glucose dependency to fuel elevated glycolysis.Altered glucose metabolism is associated with high NADH that limits serine synthesis, leading to impaired GSH and nucleotide production.Mitochondrial respiration defects sensitize NSCLC to dietary serine/glycine starvation, further increasing survival.

Abstract Figure

Unlocking mitochondrial drug targets: The importance of mitochondrial transport proteins

A disturbed mitochondrial function contributes to the pathology of many common diseases. These organelles are therefore important therapeutic targets. On the contrary, many adverse effects of drugs can be explained by a mitochondrial off-target effect, in particular, due to an interaction with carrier proteins in the inner membrane. Yet this class of transport proteins remains underappreciated and understudied. The aim of this review is to provide a deeper understanding of the role of mitochondrial carriers in health and disease and their significance as drug targets. We present literature-based evidence that mitochondrial carrier proteins are associated with prevalent diseases and emphasize their potential as drug (off-)target sites by summarizing known mitochondrial drug-transporter interactions. Studying these carriers will enhance our knowledge of mitochondrial drug on- and off-targets and provide opportunities to further improve the efficacy and safety of drugs.

Devastating the Supply Wagons: Multifaceted Liposomes Capable of Exhausting Tumor to Death via Triple Energy Depletion

The anabolism of tumor cells can not only support their proliferation, but also endow them with a steady influx of exogenous nutrients. Therefore, consuming metabolic substrates or limiting access to energy supply can be an effective strategy to impede tumor growth. Herein, a novel treatment paradigm of starving-like therapy-triple energy-depleting therapy-is illustrated by glucose oxidase (GOx)/dc-IR825/sorafenib liposomes (termed GISLs), and such a triple energy-depleting therapy exhibits a more effective tumor-killing effect than conventional starvation therapy that only cuts off one of the energy supplies. Specifically, GOx can continuously consume glucose and generate toxic H2O2 in the tumor microenvironment (including tumor cells). After endocytosis, dc-IR825 (a near-infrared cyanine dye) can precisely target mitochondria and exert photodynamic and photothermal activities upon laser irradiation to destroy mitochondria. The anti-angiogenesis effect of sorafenib can further block energy and nutrition supply from blood. This work exemplifies a facile and safe method to exhaust the energy in a tumor from three aspects and starve the tumor to death and also highlights the importance of energy depletion in tumor treatment. It is hoped that this work will inspire the development of more advanced platforms that can combine multiple energy depletion therapies to realize more effective tumor treatment.

Dual inhibition of oxidative phosphorylation and glycolysis to enhance cancer therapy

Dual suppression of oxidative phosphorylation (OXPHOS) and glycolysis can disrupt metabolic adaption of cancer cells, inhibiting energy supply and leading to successful cancer therapy. Herein, we have developed an α-tocopheryl succinate (α-TOS)-functionalized iridium(III) complex Ir2, a highly lipophilic mitochondria targeting anticancer molecule, could inhibit both oxidative phosphorylation (OXPHOS) and glycolysis, resulting in the energy blockage and cancer growth suppression. Mechanistic studies reveal that complex Ir2 induces reactive oxygen species (ROS) elevation and mitochondrial depolarization, and triggers DNA oxidative damage. These damages could evoke the cancer cell death with the mitochondrial-relevant apoptosis and autophagy. 3D tumor spheroids experiment demonstrates that Ir2 owned superior antiproliferation performance, as the potent anticancer agent in vivo. This study not only provided a new path for dual inhibition of both mitochondrial OXPHOS and glycolytic metabolisms with a novel α-TOS-functionalized metallodrug, but also further demonstrated that the mitochondrial-relevant therapy could be effective in enhancing the anticancer performance.

Preclinical evaluation of cyclophosphamide and fludarabine combined with CD19 CAR-T in the treatment of B-cell hematologic malignancies in vivo

Background

Chimeric antigen receptor T (CAR-T) cell therapy has achieved marked therapeutic success in ameliorating hematological malignancies. However, there is an extant void in the clinical guidelines concerning the most effective chemotherapy regimen prior to chimeric antigen receptor T (CAR-T) cell therapy, as well as the optimal timing for CAR-T cell infusion post-chemotherapy.

Materials and Methods

We employed cell-derived tumor xenograft (CDX) murine models to delineate the optimal pre-conditioning chemotherapy regimen and timing for CAR-T cell treatment. Furthermore, transcriptome sequencing was implemented to identify the therapeutic targets and elucidate the underlying mechanisms governing the treatment regimen.

Results

Our preclinical in vivo evaluation determined that a combination of cyclophosphamide and fludarabine, followed by the infusion of CD19 CAR-T cells five days subsequent to the chemotherapy, exerts the most efficacious therapeutic effect in B-cell hematological malignancies. Concurrently, RNA-seq data indicated that the therapeutic efficacy predominantly perturbs tumor cell metabolism, primarily through the inhibition of key mitochondrial targets, such as C-Jun Kinase enzyme (C-JUN).

Conclusion

In summary, the present study offers critical clinical guidance and serves as an authoritative reference for the deployment of CD19 CAR-T cell therapy in the treatment of B-cell hematological malignancies.

A mitochondria-targeting heptamethine cyanine-chlorambucil formulated polymeric nanoparticle to potentiate native tumor chemotherapeutic efficacy

Chlorambucil (Cbl) is a DNA alkylating drug in the nitrogen mustard family, but the clinical applications of nitrogen mustard antitumor drugs are frequently limited by their poor aqueous solubility, poor cellular uptake, lack of targeting, and severe side effects. Additionally, mitochondria are the energy factories for cells, and tumor cells are more susceptible to mitochondrial dysfunction than some healthy cells, thus making mitochondria an important target for tumor therapy. As a proof-of-concept, direct delivery of Cbl to tumor cells' mitochondria will probably bring about new opportunities for the nitrogen mustard family. Furthermore, IR775 chloride is a small-molecule lipophilic cationic heptamethine cyanine dye with potential advantages of mitochondria targeting, near-infrared (NIR) fluorescence imaging, and preferential internalization towards tumor cells. Here, an amphiphilic drug conjugate was facilely prepared by covalently coupling chlorambucil with IR775 chloride and further self-assembly to form a carrier-free self-delivery theranostic system, in which the two components are both functional units aimed at theranostic improvement. The theranostic IR775-Cbl potentiated typical "1 + 1 > 2" tumor inhibition through specific accumulation in mitochondria, which triggered a remarkable decrease in mitochondrial membrane potential and ATP generation. In vivo biodistribution and kinetic monitoring were achieved by real-time NIR fluorescence imaging to observe its transport inside a living body. Current facile mitochondria-targeting modification with clinically applied drugs was promising for endowing traditional drugs with targeting, imaging, and improved potency in disease theranostics.

Modular Engineering of Aptamer-Based Nanobiotechnology for Conditional Control of ATP Sensing

Dynamic changes of intracellular, extracellular, and subcellular adenosine triphosphates (ATPs) have fundamental interdependence with the physio-pathological states of cells. Spatially selective in situ imaging of such ATP dynamics offers valuable mechanistic insights into the related biological activities. Despite significant advances in the design of aptamer sensors for ATP detection, the dearth of methods that enable precise ATP imaging in specific cellular locations remains a challenge in this field. This review focuses on the modular engineering of regulatable sensing technology via the integration of aptamer probe designs with advanced functional nanomaterials, allowing conditional control of ATP sensing and imaging with high spatial precision from subcellular organelles to living animals. Highlighting the recent advances in the design of photo-triggered nanosensors for spatiotemporally controlled ATP imaging, endogenously-triggered ATP sensing in a cell-selective manner, and spatially-controlled nanodevices for ATP imaging in specific organelles and extracellular microenvironments. Emphasis will be put on elucidating the principles of how nanotechnology can be applied to regulate the spatial precision of aptamer-based ATP sensing activities. The authors envision that this perspective provides insights into the engineering of aptamer-based nanobiotechnology for opening new frontiers in precise molecular sensing and other bio-applications.

High PGC-1α Expression as a Poor Prognostic Indicator in Intracranial Glioma

Gliomas are the most common primary brain tumors in adults. Despite multidisciplinary treatment approaches, the survival rates for patients with malignant glioma have only improved marginally, and few prognostic biomarkers have been identified. Peroxisome proliferator-activated receptor γ (PPARγ) coactivator-1α (PGC-1α) is a crucial regulator of cancer metabolism, playing a vital role in cancer cell adaptation to fluctuating energy demands. In this study, the clinicopathological roles of PGC-1α in gliomas were evaluated. Employing immunohistochemistry, cell culture, siRNA transfection, cell viability assays, western blot analyses, and in vitro and in vivo invasion and migration assays, we explored the functions of PGC-1α in glioma progression. High PGC-1α expression was significantly associated with an advanced pathological stage in patients with glioma and with poorer overall survival. The downregulation of PGC-1α inhibited glioma cell proliferation, invasion, and migration and altered the expression of oncogenic markers. These results conclusively demonstrated that PGC-1α plays a critical role in maintaining the malignant phenotype of glioma cells and indicated that targeting PGC-1α could be an effective strategy to curb glioma progression and improve patient survival outcomes.

Electrochemical control of the morphological evolution of PEDOT on a Ni-Co(OH)2/carbon cloth surface to modulate the performance of wearable H2O2 sensors

The slow redox rate of hydrogen peroxide (H2O2) in neutral environments makes the H2O2 sensor inadequate for the detection of low levels of signalling molecules. The aim of this study is to fabricate a flexible sensing electrode by hydrothermally loading micro-nanometer Ni and Co(OH)2 on carbon cloth (CC) and electrochemically depositing poly(3,4-ethylenedioxythiophene) (PEDOT) on the surface of the electrode. The sensor presented high sensitivity (10.43 mA mM-1 cm-2), a wide detection range (0.033-120.848 mM), a low detection limit (0.92 nM), high stability, and excellent anti-interference performance in neutral solutions. Ni-Co(OH)2 provides abundant active sites while CC solves their agglomeration phenomenon and conductivity. The PEDOT film offers heightened conductivity, hydrophilicity, interfacial stability, and an electrochemically active surface area (ECSA). The side area of the chrysanthemum petal like PEDOT is 39 ± 7 times the bottom area, and PEDOT increases the ECSA of the composite to six times that of CC. Electrochemical precise control of PEDOT morphology to improve sensor performance provides a new strategy for the application of PEDOT in sensors.

Integrated multi-omics analysis and machine learning developed a prognostic model based on mitochondrial function in a large multicenter cohort for Gastric Cancer

BACKGROUND

Gastric cancer (GC) is a common and aggressive type of cancer worldwide. Despite recent advancements in its treatment, the prognosis for patients with GC remains poor. Understanding the mechanisms of cell death in GC, particularly those related to mitochondrial function, is crucial for its development and progression. However, more research is needed to investigate the significance of the interaction between mitochondrial function and GC cell death.

METHODS

We employed a robust computational framework to investigate the role of mitochondria-associated proteins in the progression of GC in a cohort of 1,199 GC patients. Ten machine learning algorithms were utilized and combined into 101 unique combinations. Ultimately, we developed a Mitochondrial-related-Score (MitoScore) using the machine learning model that exhibited the best performance. We observed the upregulation of LEMT2 and further explored its function in tumor progression. Mitochondrial functions were assessed by measuring mitochondrial ATP, mitochondrial membrane potential, and levels of lactate, pyruvate, and glucose.

RESULTS

MitoScore showed significant correlations with GC immune and metabolic functions. The higher MitoScore subgroup exhibited enriched metabolic pathways and higher immune activity. Overexpression of LETM2 (leucine zipper and EF-hand containing transmembrane protein 2) significantly enhanced tumor proliferation and metastasis. LETM2 plays a role in promoting GC cell proliferation by activating the mTOR pathway, maintaining mitochondrial homeostasis, and promoting glycolysis.

CONCLUSION

The powerful machine learning framework highlights the significant potential of MitoScore in providing valuable insights and accurate assessments for individuals with GC. This study also enhances our understanding of LETM2 as an oncogene signature in GC. LETM2 may promote tumor progression by maintaining mitochondrial health and activating glycolysis, offering potential targets for diagnosis, treatment, and prognosis of GC.

Inhibition of Carbohydrate Metabolism Potentiated by the Therapeutic Effects of Oxidative Phosphorylation Inhibitors in Colon Cancer Cells

Cancer cells undergo a significant level of "metabolic reprogramming" or "remodeling" to ensure an adequate supply of ATP and "building blocks" for cell survival and to facilitate accelerated proliferation. Cancer cells preferentially use glycolysis for ATP production (the Warburg effect); however, cancer cells, including colorectal cancer (CRC) cells, also depend on oxidative phosphorylation (OXPHOS) for ATP production, a finding that suggests that both glycolysis and OXPHOS play significant roles in facilitating cancer progression and proliferation. Our prior studies identified a semisynthetic isoflavonoid, DBI-1, that served as an AMPK activator targeting mitochondrial complex I. Furthermore, DBI-1 and a glucose transporter 1 (GLUT1) inhibitor, BAY-876, synergistically inhibited CRC cell growth in vitro and in vivo. We now report a study of the structure-activity relationships (SARs) in the isoflavonoid family in which we identified a new DBI-1 analog, namely, DBI-2, with promising properties. Here, we aimed to explore the antitumor mechanisms of DBIs and to develop new combination strategies by targeting both glycolysis and OXPHOS. We identified DBI-2 as a novel AMPK activator using an AMPK phosphorylation assay as a readout. DBI-2 inhibited mitochondrial complex I in the Seahorse assays. We performed proliferation and Western blotting assays and conducted studies of apoptosis, necrosis, and autophagy to corroborate the synergistic effects of DBI-2 and BAY-876 on CRC cells in vitro. We hypothesized that restricting the carbohydrate uptake with a KD would mimic the effects of GLUT1 inhibitors, and we found that a ketogenic diet significantly enhanced the therapeutic efficacy of DBI-2 in CRC xenograft mouse models, an outcome that suggested a potentially new approach for combination cancer therapy.

Targeting Group 3 Medulloblastoma by the Anti-PRUNE-1 and Anti-LSD1/KDM1A Epigenetic Molecules

Medulloblastoma (MB) is a highly malignant childhood brain tumor. Group 3 MB (Gr3 MB) is considered to have the most metastatic potential, and tailored therapies for Gr3 MB are currently lacking. Gr3 MB is driven by PRUNE-1 amplification or overexpression. In this paper, we found that PRUNE-1 was transcriptionally regulated by lysine demethylase LSD1/KDM1A. This study aimed to investigate the therapeutic potential of inhibiting both PRUNE-1 and LSD1/KDM1A with the selective inhibitors AA7.1 and SP-2577, respectively. We found that the pharmacological inhibition had a substantial efficacy on targeting the metastatic axis driven by PRUNE-1 (PRUNE-1-OTX2-TGFβ-PTEN) in Gr3 MB. Using RNA seq transcriptomic feature data in Gr3 MB primary cells, we provide evidence that the combination of AA7.1 and SP-2577 positively affects neuronal commitment, confirmed by glial fibrillary acidic protein (GFAP)-positive differentiation and the inhibition of the cytotoxic components of the tumor microenvironment and the epithelial-mesenchymal transition (EMT) by the down-regulation of N-Cadherin protein expression. We also identified an impairing action on the mitochondrial metabolism and, consequently, oxidative phosphorylation, thus depriving tumors cells of an important source of energy. Furthermore, by overlapping the genomic mutational signatures through WES sequence analyses with RNA seq transcriptomic feature data, we propose in this paper that the combination of these two small molecules can be used in a second-line treatment in advanced therapeutics against Gr3 MB. Our study demonstrates that the usage of PRUNE-1 and LSD1/KDM1A inhibitors in combination represents a novel therapeutic approach for these highly aggressive metastatic MB tumors.

Platinum iodido drugs show potential anti-tumor activity, affecting cancer cell metabolism and inducing ROS and senescence in gastrointestinal cancer cells

Cisplatin-based chemotherapy has associated clinical disadvantages, such as high toxicity and resistance. Thus, the development of new antitumor metallodrugs able to overcome different clinical barriers is a public healthcare priority. Here, we studied the mechanism of action of the isomers trans and cis-[PtI2(isopropylamine)2] (I5 and I6, respectively) against gastrointestinal cancer cells. We demonstrate that I5 and I6 modulate mitochondrial metabolism, decreasing OXPHOS activity and negatively affecting ATP-linked oxygen consumption rate. Consequently, I5 and I6 generated Reactive Oxygen Species (ROS), provoking oxidative damage and eventually the induction of senescence. Thus, herein we propose a loop with three interconnected processes modulated by these iodido agents: (i) mitochondrial dysfunction and metabolic disruptions; (ii) ROS generation and oxidative damage; and (iii) cellular senescence. Functionally, I5 reduces cancer cell clonogenicity and tumor growth in a pancreatic xenograft model without systemic toxicity, highlighting a potential anticancer complex that warrants additional pre-clinical studies.