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Journal of Hematology & Oncology Jul 2023Tumour-associated macrophages (TAMs) are crucial components of the tumour microenvironment and play a significant role in tumour development and drug resistance by... (Review)
Review
Tumour-associated macrophages (TAMs) are crucial components of the tumour microenvironment and play a significant role in tumour development and drug resistance by creating an immunosuppressive microenvironment. Macrophages are essential components of both the innate and adaptive immune systems and contribute to pathogen resistance and the regulation of organism homeostasis. Macrophage function and polarization are closely linked to altered metabolism. Generally, M1 macrophages rely primarily on aerobic glycolysis, whereas M2 macrophages depend on oxidative metabolism. Metabolic studies have revealed that the metabolic signature of TAMs and metabolites in the tumour microenvironment regulate the function and polarization of TAMs. However, the precise effects of metabolic reprogramming on tumours and TAMs remain incompletely understood. In this review, we discuss the impact of metabolic pathways on macrophage function and polarization as well as potential strategies for reprogramming macrophage metabolism in cancer treatment.
Topics: Humans; Macrophages; Neoplasms; Tumor-Associated Macrophages; Metabolic Networks and Pathways; Tumor Microenvironment
PubMed: 37491279
DOI: 10.1186/s13045-023-01478-6 -
Cell Chemical Biology Oct 2023Targeting transcription replication conflicts, a major source of endogenous DNA double-stranded breaks and genomic instability could have important anticancer...
Targeting transcription replication conflicts, a major source of endogenous DNA double-stranded breaks and genomic instability could have important anticancer therapeutic implications. Proliferating cell nuclear antigen (PCNA) is critical to DNA replication and repair processes. Through a rational drug design approach, we identified a small molecule PCNA inhibitor, AOH1996, which selectively kills cancer cells. AOH1996 enhances the interaction between PCNA and the largest subunit of RNA polymerase II, RPB1, and dissociates PCNA from actively transcribed chromatin regions, while inducing DNA double-stranded breaks in a transcription-dependent manner. Attenuation of RPB1 interaction with PCNA, by a point mutation in RPB1's PCNA-binding region, confers resistance to AOH1996. Orally administrable and metabolically stable, AOH1996 suppresses tumor growth as a monotherapy or as a combination treatment but causes no discernable side effects. Inhibitors of transcription replication conflict resolution may provide a new and unique therapeutic avenue for exploiting this cancer-selective vulnerability.
Topics: Humans; Proliferating Cell Nuclear Antigen; Chromatin; Protein Binding; Neoplasms; DNA; DNA Replication
PubMed: 37531956
DOI: 10.1016/j.chembiol.2023.07.001 -
Cell Death & Disease Aug 2023Ferroptosis is a form of regulated cell death induced by iron-dependent lipid peroxidation, and it has been studied extensively since its discovery in 2012. Induced by... (Review)
Review
Ferroptosis is a form of regulated cell death induced by iron-dependent lipid peroxidation, and it has been studied extensively since its discovery in 2012. Induced by iron overload and ROS accumulation, ferroptosis is modulated by various cellular metabolic and signaling pathways. The GSH-GPX4 pathway, the FSP1-CoQ10 pathway, the GCH1-BH4 pathway, the DHODH-CoQH2 system and the sex hormones suppress ferroptosis. Mitochondrial iron metabolism regulates ferroptosis and mitochondria also undergo a morphological change during ferroptosis, these changes include increased membrane density and reduced mitochondrial cristae. Moreover, mitochondrial energy metabolism changes during ferroptosis, the increased oxidative phosphorylation and ATP production rates lead to a decrease in the glycolysis rate. In addition, excessive oxidative stress induces irreversible damage to mitochondria, diminishing organelle integrity. ROS production, mitochondrial membrane potential, mitochondrial fusion and fission, and mitophagy also function in ferroptosis. Notably, some ferroptosis inhibitors target mitochondria. Ferroptosis is a major mechanism for cell death associated with the progression of cancer. Metastasis-prone or metastatic cancer cells are more susceptible to ferroptosis. Inducing ferroptosis in tumor cells shows very promising potential for treating drug-resistant cancers. In this review, we present a brief retrospect of the discovery and the characteristics of ferroptosis, then we discuss the regulation of ferroptosis and highlight the unique role played by mitochondria in the ferroptosis of cancer cells. Furthermore, we explain how ferroptosis functions as a double-edged sword as well as novel therapies aimed at selectively manipulating cell death for cancer eradication.
Topics: Ferroptosis; Reactive Oxygen Species; Mitochondria; Oxidative Stress; Iron; Neoplasms
PubMed: 37580393
DOI: 10.1038/s41419-023-06045-y -
Nutrients Oct 2023Cancer is amenable to low-cost treatments, given that it has a significant metabolic component, which can be affected through diet and lifestyle change at minimal cost.... (Review)
Review
Cancer is amenable to low-cost treatments, given that it has a significant metabolic component, which can be affected through diet and lifestyle change at minimal cost. The Warburg hypothesis states that cancer cells have an altered cell metabolism towards anaerobic glycolysis. Given this metabolic reprogramming in cancer cells, it is possible to target cancers metabolically by depriving them of glucose. In addition to dietary and lifestyle modifications which work on tumors metabolically, there are a panoply of nutritional supplements and repurposed drugs associated with cancer prevention and better treatment outcomes. These interventions and their evidentiary basis are covered in the latter half of this review to guide future cancer treatment.
Topics: Humans; Neoplasms; Glycolysis; Energy Metabolism; Treatment Outcome
PubMed: 37836529
DOI: 10.3390/nu15194245 -
Nature Mar 2024Targeted protein degradation is a pharmacological modality that is based on the induced proximity of an E3 ubiquitin ligase and a target protein to promote target...
Targeted protein degradation is a pharmacological modality that is based on the induced proximity of an E3 ubiquitin ligase and a target protein to promote target ubiquitination and proteasomal degradation. This has been achieved either via proteolysis-targeting chimeras (PROTACs)-bifunctional compounds composed of two separate moieties that individually bind the target and E3 ligase, or via molecular glues that monovalently bind either the ligase or the target. Here, using orthogonal genetic screening, biophysical characterization and structural reconstitution, we investigate the mechanism of action of bifunctional degraders of BRD2 and BRD4, termed intramolecular bivalent glues (IBGs), and find that instead of connecting target and ligase in trans as PROTACs do, they simultaneously engage and connect two adjacent domains of the target protein in cis. This conformational change 'glues' BRD4 to the E3 ligases DCAF11 or DCAF16, leveraging intrinsic target-ligase affinities that do not translate to BRD4 degradation in the absence of compound. Structural insights into the ternary BRD4-IBG1-DCAF16 complex guided the rational design of improved degraders of low picomolar potency. We thus introduce a new modality in targeted protein degradation, which works by bridging protein domains in cis to enhance surface complementarity with E3 ligases for productive ubiquitination and degradation.
Topics: Bromodomain Containing Proteins; Cell Cycle Proteins; Drug Design; Proteasome Endopeptidase Complex; Proteolysis; Proteolysis Targeting Chimera; Transcription Factors; Ubiquitin-Protein Ligases; Ubiquitination; Protein Binding; Substrate Specificity; Protein Domains
PubMed: 38383787
DOI: 10.1038/s41586-024-07089-6 -
EBioMedicine Jan 2024Humans are exposed to micro-and-nano plastics (MNPs) through various routes, but the adverse health effects of MNPs on different organ systems are not yet fully... (Review)
Review
Humans are exposed to micro-and-nano plastics (MNPs) through various routes, but the adverse health effects of MNPs on different organ systems are not yet fully understood. This review aims to provide an overview of the potential impacts of MNPs on various organ systems and identify knowledge gaps in current research. The summarized results suggest that exposure to MNPs can lead to health effects through oxidative stress, inflammation, immune dysfunction, altered biochemical and energy metabolism, impaired cell proliferation, disrupted microbial metabolic pathways, abnormal organ development, and carcinogenicity. There is limited human data on the health effects of MNPs, despite evidence from animal and cellular studies. Most of the published research has focused on specific types of MNPs to assess their toxicity, while other types of plastic particles commonly found in the environment remain unstudied. Future studies should investigate MNPs exposure by considering realistic concentrations, dose-dependent effects, individual susceptibility, and confounding factors.
Topics: Animals; Humans; Microplastics; Cell Proliferation; Drug-Related Side Effects and Adverse Reactions; Energy Metabolism; Inflammation; Water Pollutants, Chemical
PubMed: 38061242
DOI: 10.1016/j.ebiom.2023.104901 -
The Journal of Clinical Investigation Jan 2024Immunometabolism is a burgeoning field of research that investigates how immune cells harness nutrients to drive their growth and functions. Myeloid cells play a pivotal... (Review)
Review
Immunometabolism is a burgeoning field of research that investigates how immune cells harness nutrients to drive their growth and functions. Myeloid cells play a pivotal role in tumor biology, yet their metabolic influence on tumor growth and antitumor immune responses remains inadequately understood. This Review explores the metabolic landscape of tumor-associated macrophages, including the immunoregulatory roles of glucose, fatty acids, glutamine, and arginine, alongside the tools used to perturb their metabolism to promote antitumor immunity. The confounding role of metabolic inhibitors on our interpretation of myeloid metabolic phenotypes will also be discussed. A binary metabolic schema is currently used to describe macrophage immunological phenotypes, characterizing inflammatory M1 phenotypes, as supported by glycolysis, and immunosuppressive M2 phenotypes, as supported by oxidative phosphorylation. However, this classification likely underestimates the variety of states in vivo. Understanding these nuances will be critical when developing interventional metabolic strategies. Future research should focus on refining drug specificity and targeted delivery methods to maximize therapeutic efficacy.
Topics: Humans; Macrophages; Oxidative Phosphorylation; Myeloid Cells; Immunotherapy; Neoplasms
PubMed: 38226622
DOI: 10.1172/JCI175445 -
Journal of Hematology & Oncology Aug 2023RNA modification has recently become a significant process of gene regulation, and the methyltransferase-like (METTL) family of proteins plays a critical role in RNA... (Review)
Review
RNA modification has recently become a significant process of gene regulation, and the methyltransferase-like (METTL) family of proteins plays a critical role in RNA modification, methylating various types of RNAs, including mRNA, tRNA, microRNA, rRNA, and mitochondrial RNAs. METTL proteins consist of a unique seven-beta-strand domain, which binds to the methyl donor SAM to catalyze methyl transfer. The most typical family member METTL3/METTL14 forms a methyltransferase complex involved in N6-methyladenosine (m6A) modification of RNA, regulating tumor proliferation, metastasis and invasion, immunotherapy resistance, and metabolic reprogramming of tumor cells. METTL1, METTL4, METTL5, and METTL16 have also been recently identified to have some regulatory ability in tumorigenesis, and the rest of the METTL family members rely on their methyltransferase activity for methylation of different nucleotides, proteins, and small molecules, which regulate translation and affect processes such as cell differentiation and development. Herein, we summarize the literature on METTLs in the last three years to elucidate their roles in human cancers and provide a theoretical basis for their future use as potential therapeutic targets.
Topics: Humans; Methyltransferases; Adenosine; Methylation; MicroRNAs; Biology; Neoplasms
PubMed: 37533128
DOI: 10.1186/s13045-023-01477-7 -
Theranostics 2024The hypothalamus plays a fundamental role in controlling lipid metabolism through neuroendocrine signals. However, there are currently no available drug targets in the...
The hypothalamus plays a fundamental role in controlling lipid metabolism through neuroendocrine signals. However, there are currently no available drug targets in the hypothalamus that can effectively improve human lipid metabolism. In this study, we found that the antimalarial drug artemether (ART) significantly improved lipid metabolism by specifically inhibiting microglial activation in the hypothalamus of high-fat diet-induced mice. Mechanically, ART protects the thyrotropin-releasing hormone (TRH) neurons surrounding microglial cells from inflammatory damage and promotes the release of TRH into the peripheral circulation. As a result, TRH stimulates the synthesis of thyroid hormone (TH), leading to a significant improvement in hepatic lipid disorders. Subsequently, we employed a biotin-labeled ART chemical probe to identify the direct cellular target in microglial cells as protein kinase Cδ (PKCδ). Importantly, ART directly targeted PKCδ to inhibit its palmitoylation modification by blocking the binding of zinc finger DHHC-type palmitoyltransferase 5 (ZDHHC5), which resulted in the inhibition of downstream neuroinflammation signaling. In vivo, hypothalamic microglia-specific PKCδ knockdown markedly impaired ART-dependent neuroendocrine regulation and lipid metabolism improvement in mice. Furthermore, single-cell transcriptomics analysis in human brain tissues revealed that the level of PKCδ in microglia positively correlated with individuals who had hyperlipemia, thereby highlighting a clinical translational value. Collectively, these data suggest that the palmitoylation of microglial PKCδ in the hypothalamus plays a role in modulating peripheral lipid metabolism through hypothalamus-liver communication, and provides a promising therapeutic target for fatty liver diseases.
Topics: Humans; Animals; Mice; Lipoylation; Microglia; Hypothalamus; Non-alcoholic Fatty Liver Disease; Lipid Metabolism; Artemether
PubMed: 38250049
DOI: 10.7150/thno.89602