The HIF-1α antisense long non-coding RNA drives a positive feedback loop of HIF-1α mediated transactivation and glycolysis

Unraveling the differential tolerance mechanisms of Acropora formosa and Montipora digitata to Benzo[a]pyrene (BaP) exposure via 4D proteomics

Coral reefs are suffering from environmental pollution worldwide, implying unprecedented survival challenges. In this paper we investigate the effects of the Benzo[a]pyrene (BaP) on the survival status of coral and explore its potential tolerance mechanism. By applying advanced 4D proteomics techniques, we systematically compared the differences in the protein expression profiles of Acropora formosa (A. formosa) and Montipora digitata (M. digitata) under BaP exposure conditions (50 μg/L, 72 h and 120 h). Under the same BaP exposure conditions, the bleaching rate of A. formosa was faster, and the zooxanthellae density and chlorophyll content were lower. M. digitata showed higher BaP tolerance than A. formosa, may attributed to significantly enhanced protein synthesis, folding, and stability in its host cells, as well as a more efficient energy metabolism mechanism. While A. formosa coral hosts showed low protein stability and high ferritin expression, and iron metabolism imbalance was aggravated under BaP stress, which increased oxidative stress damage. Specifically, the zooxanthellae of M. digitata without exposed to BaP showed stronger photosynthetic efficiency and glucose metabolism, especially the activation of the pyruvate metabolic pathway. However, these advantages were rapidly diminished after exposure to BaP. In response to BaP exposure, A. formosa's zooxanthellae may activated longevity related pathways and hypoxia-inducing factor signaling pathways, significantly enhancing energy metabolism pathways. This study is helpful to reveal the complex adaptive mechanism of coral reef ecosystem to environmental pollution.

Moonlighting functions of glucose metabolic enzymes and metabolites in cancer

Glucose metabolic enzymes and their metabolites not only provide energy and building blocks for synthesizing macromolecules but also possess non-canonical or moonlighting functions in response to extracellular and intracellular signalling. These moonlighting functions modulate various cellular activities, including gene expression, cell cycle progression, DNA repair, autophagy, senescence and apoptosis, cell proliferation, remodelling of the tumour microenvironment and immune responses. These functions integrate glucose metabolism with other essential cellular activities, driving cancer progression. Targeting these moonlighting functions could open new therapeutic avenues and lead to cancer-specific treatments.

Advances in the mechanisms of HIF-1α-enhanced tumor glycolysis and its relation to dedifferentiation

Metabolic reprogramming, a hallmark of malignancy, enables tumor cells to adapt to the harsh and dynamic tumor microenvironment (TME) by altering metabolic pathways. Hypoxia, prevalent in solid tumors, activates hypoxia inducible factor 1α (HIF-1α). HIF-1α drives metabolic reprogramming, enhancing glycolysis primarily through the Warburg effect to reduce oxygen dependence and facilitate tumor cell growth/proliferation. The above process is associated with accelerated tumor cell dedifferentiation and enhanced stemness, generating cancer stem cells (CSCs) which possesses the potential for self-renewal and differentiation that can differentiate into a wide range of subtypes of tumor cells and fuel tumor heterogeneity, metastasis, and recurrence, complicating therapy. This review examines the HIF-1α-glycolysis-dedifferentiation crosstalk mechanisms, expecting that indirect inhibition of HIF-1α by targeting metabolic enzymes, metabolites, or their signaling pathways will offer an effective therapeutic strategy to improve the cancer treatment outcomes.

Biotin Receptor-Targeting PtIV Oxygen Carrying Prodrug Amphiphile for Alleviating Tumor Hypoxia Induced Immune Chemotherapy Suppression

Platinum (Pt)-based chemotherapeutic agents, known for their potent cytotoxicity, are extensively used in clinical oncology. However, their therapeutic efficacy is severely limited by a variety of factors, particularly the hypoxic tumor microenvironment (TME), which not only impedes effective drug delivery but also triggers immune suppression, further diminishing the antitumor effects of Pt drugs. In response to these challenges, we have developed a biotin receptor (BR)-targeting oxaliplatin (OXA)-based PtIV prodrug, named Lipo-OPtIV-BT, which could encapsulate hemoglobin (Hb) as an oxygen carrier, forming PtIV-loaded lipid nanoparticles (Hb@BTOPtIV). The design of the Hb@BTOPtIV aims to address the dual issues of poor drug delivery and immune suppression by effectively increasing local oxygen tension in the TME. Notably, our findings demonstrate that the cytotoxic effects of the BR-targeting PtIV prodrug and increased oxygen levels synergistically reverse the tumor immune microenvironment, leading to improved antitumor efficacy. We observed that Hb@BTOPtIV significantly improved the biodistribution of the drug, enabling it to preferentially accumulate in tumor regions. Importantly, the enhanced oxygenation within the TME also plays a critical role in reshaping the immune landscape of the tumor, promoting a more favorable immune environment for effective chemotherapy. This reversal of immune suppression is evidenced by increased infiltration of cytotoxic T cells and reduced levels of regulatory T cells (Tregs) within the tumor. These findings highlight the promising potential of using BR-targeting lipid PtIV prodrug amphiphiles to improve drug accumulation at tumor sites and counteract immunosuppression induced by tumor hypoxia.

Exploring the role of glycolysis in the pathogenesis of erectile dysfunction in diabetes

Background

Diabetes mellitus-related erectile dysfunction (DMED) is characterized by complicated pathogenesis and unsatisfactory therapeutic remedies. Glycolysis plays an essential role in diabetic complications and whether it is involved in the process of DMED has not been expounded. The aim of this study was to investigate the genetic profiling of glycolysis and explore potential mechanisms for DMED.

Methods

Glycolysis-related genes (GRGs) and gene expression matrix of DMED were obtained from the molecular signatures database and gene expression omnibus dataset. Differentially expressed analysis and support vector machine-recursive feature elimination (SVM-RFE) method were both used to obtain hub GRGs. Interactive network and functional enrichment analyses were performed to clarify the associated biological roles of these genes. The expression profile of hub GRGs was validated in cavernous endothelial cells, animals, and clinical patients. The subpopulation distribution of hub GRGs was further identified. In addition, a miRNA-GRGs network was constructed and expression patterns as well as molecular functions of relevant miRNAs were explored and validated. In addition, the relationship between hypoxia and DMED was also uncovered.

Results

Based on the combined analysis, 48 differentially expressed GRGs were obtained. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses revealed that these genes were significantly enriched in carbon metabolism and oxidoreductase activities. Then hub GRGs including down-regulated as well as up-regulated genes in DMED were identified ultimately. Among them, ALDOC, ANGPTL4, and CITED2 were well-validated. In addition, 334 glycolysis-related miRNAs were verified and they were involved in endoplasmic reticulum membrane activity, smooth muscle cell differentiation and angiogenesis. After validation of miRNA signature in DMED patients, miR-222-5p, let-7e-5p, miR-184, and miR-122-3p were identified as the promising glycolysis-related miRNA biomarkers in DMED.

Conclusions

We clarified the expression signature of GRGs in DMED based on multi-omics analysis for the first time. It will be significantly important to reveal pathological mechanisms and promising treatments in DMED.

The multiple functions and mechanisms of long non-coding RNAs in regulating breast cancer progression

Breast cancer (BC) is a malignant tumor that has the highest morbidity and mortality rates in the female population, and its high tendency to metastasize is the main cause of poor clinical prognosis. Long non-coding RNAs (lncRNAs) have been extensively documented to exhibit aberrant expression in various cancers and influence tumor progression via multiple molecular pathways. These lncRNAs not only modulate numerous aspects of gene expression in cancer cells, such as transcription, translation, and post-translational modifications, but also play a crucial role in the reprogramming of energy metabolism by regulating metabolic regulators, which is particularly significant in advanced BC. This review examines the characteristics and mechanisms of lncRNAs in regulating BC cells, both intracellularly (e.g., cell cycle, autophagy) and extracellularly (e.g., tumor microenvironment). Furthermore, we explore the potential of specific lncRNAs and their regulatory factors as molecular markers and therapeutic targets. Lastly, we summarize the application of lncRNAs in the treatment of advanced BC, aiming to offer novel personalized therapeutic options for patients.

Unraveling the triad of hypoxia, cancer cell stemness, and drug resistance

In the domain of addressing cancer resistance, challenges such as limited effectiveness and treatment resistance remain persistent. Hypoxia is a key feature of solid tumors and is strongly associated with poor prognosis in cancer patients. Another significant portion of the development of acquired drug resistance is attributed to tumor stemness. Cancer stem cells (CSCs), a small tumor cell subset with self-renewal and proliferative abilities, are crucial for tumor initiation, metastasis, and intra-tumoral heterogeneity. Studies have shown a significant association between hypoxia and CSCs in the context of tumor resistance. Recent studies reveal a strong link between hypoxia and tumor stemness, which together promote tumor survival and progression during treatment. This review elucidates the interplay between hypoxia and CSCs, as well as their correlation with resistance to therapeutic drugs. Targeting pivotal genes associated with hypoxia and stemness holds promise for the development of novel therapeutics to combat tumor resistance.

SNHG17 Reprograms Energy Metabolism of Breast Cancer by Activating Mitochondrial DNA Transcription

In most solid tumors, cellular energy metabolism is primarily dominated by aerobic glycolysis, which fulfills the high demand for biomacromolecules at the expense of reduced ATP production efficiency. Elucidation of the mechanisms by which rapidly proliferating malignant cells acquire sufficient energy in this state of inefficient ATP production from glycolysis could enable the development of metabolism-targeted therapeutic strategies. In this study, we observed a significant association between elevated expression levels of the long noncoding RNA small nuclear RNA host gene 17 (SNHG17) and unfavorable prognosis in breast cancer. SNHG17 promoted breast cancer cell proliferation by augmenting mitochondrial ATP production. Mechanistically, SNHG17 directly interacted with the P65 subunit of NF-κB and phosphorylated P65 at the threonine 505 site. SNHG17 bound to P65 at its truncated loop2 site, recruited P65 to mitochondria, and coregulated the transcriptional activation of mitochondrial DNA to promote ATP production. Accordingly, targeting SNHG17 with an antisense oligonucleotide significantly reduced breast cancer tumor growth both in vitro and in vivo. Overall, these results established a role for SNHG17 in promoting breast cancer progression by increasing ATP production and provided insights into the reprogramming of energy metabolism in solid tumors. Significance: SNHG17 cooperates with NF-κB to induce expression of mitochondrial DNA and boost ATP production in breast cancer, suggesting that targeting SNHG17 could reverse metabolic reprogramming to suppress tumor progression.

HOTAIR Participation in Glycolysis and Glutaminolysis Through Lactate and Glutamate Production in Colorectal Cancer

Metabolic reprogramming plays a crucial role in cancer biology and the mechanisms underlying its regulation represent a promising study area. In this regard, the discovery of non-coding RNAs opened a new regulatory landscape, which is in the early stages of investigation. Using a differential expression model of HOTAIR, we evaluated the expression level of metabolic enzymes, as well as the metabolites produced by glycolysis and glutaminolysis. Our results demonstrated the regulatory effect of HOTAIR on the expression of glycolysis and glutaminolysis enzymes in colorectal cancer cells. Specifically, through the overexpression and inhibition of HOTAIR, we determined its influence on the expression of the enzymes PFKFB4, PGK1, LDHA, SLC1A5, GLUD1, and GOT1, which had a direct impact on lactate and glutamate production. These findings indicate that HOTAIR plays a significant role in producing "oncometabolites" essential to maintaining the bioenergetics and biomass necessary for tumor cell survival by regulating glycolysis and glutaminolysis.

Irf7 aggravates prostatitis by promoting Hif-1α-mediated glycolysis to facilitate M1 polarization

BACKGROUND

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a common disorder associated with voiding symptoms and pain in the pelvic or perineal area. Macrophages, particularly the pro-inflammatory M1 subtype, are crucial initiating of CP/CPPS. Interferon regulatory factor 7 (Irf7) has been implicated in promoting M1 polarization, contributing to the onset and progression of autoimmunity. However, the role of Irf7 in the etiology and progression of CP/CPPS remains unclear.

METHOD

We established the experimental autoimmune prostatitis (EAP) mouse model by subcutaneous injection of prostate antigen combined with complete Freund's adjuvant. Six weeks after the first immunization, we analyzed the prostates, spleen, and blood to assess the degree of prostate inflammation, Irf7 expression levels, glycolysis, and M1 polarization to evaluate whether Irf7 could exacerbate the development of EAP by enhancing Hif-1α transcription, thereby increasing glycolysis and M1 polarization. Further investigations included sh-Irf7 intervention, Dimethyloxalylglycine (a Hif-1α agonist), and in vitro M1 polarization experiments. We also employed ChIP assays, dual-luciferase reporter assays, and q-PCR to explore if Irf7 could directly interact with the Hif-1α promoter in macrophages.

RESULTS

In the EAP mouse and cell models, elevated Irf7 expression was observed in inflamed tissues and cells. Reducing Irf7 expression decreased M1 cell glycolysis by inhibiting the nuclear translocation of Hif-1α, thus mitigating M1 cell polarization. Additionally, Irf7 was identified as a transcription factor that regulates Hif-1α transcription by interacting with its promoter in macrophages, confirmed through ChIP and dual-luciferase assays. Co-culturing macrophage cells with 3T3 fibroblasts with reduced Irf7 levels resulted in decreased fibrosis, and a significant reduction in prostate tissue fibrosis was noted in mice with Irf7 knockdown.

CONCLUSION

Our findings indicate that Irf7 can contribute to the development and progression of CP/CPPS by promoting glycolysis, which can enhance both M1 polarization as well as interstitial fibrosis in the prostate. This process was found to be mediated by the upregulation of Hif-1α transcription, presenting new potential therapeutic targets for managing CP/CPPS.

Energy metabolism in health and diseases

Energy metabolism is indispensable for sustaining physiological functions in living organisms and assumes a pivotal role across physiological and pathological conditions. This review provides an extensive overview of advancements in energy metabolism research, elucidating critical pathways such as glycolysis, oxidative phosphorylation, fatty acid metabolism, and amino acid metabolism, along with their intricate regulatory mechanisms. The homeostatic balance of these processes is crucial; however, in pathological states such as neurodegenerative diseases, autoimmune disorders, and cancer, extensive metabolic reprogramming occurs, resulting in impaired glucose metabolism and mitochondrial dysfunction, which accelerate disease progression. Recent investigations into key regulatory pathways, including mechanistic target of rapamycin, sirtuins, and adenosine monophosphate-activated protein kinase, have considerably deepened our understanding of metabolic dysregulation and opened new avenues for therapeutic innovation. Emerging technologies, such as fluorescent probes, nano-biomaterials, and metabolomic analyses, promise substantial improvements in diagnostic precision. This review critically examines recent advancements and ongoing challenges in metabolism research, emphasizing its potential for precision diagnostics and personalized therapeutic interventions. Future studies should prioritize unraveling the regulatory mechanisms of energy metabolism and the dynamics of intercellular energy interactions. Integrating cutting-edge gene-editing technologies and multi-omics approaches, the development of multi-target pharmaceuticals in synergy with existing therapies such as immunotherapy and dietary interventions could enhance therapeutic efficacy. Personalized metabolic analysis is indispensable for crafting tailored treatment protocols, ultimately providing more accurate medical solutions for patients. This review aims to deepen the understanding and improve the application of energy metabolism to drive innovative diagnostic and therapeutic strategies.

Coptisine improves LPS-induced anxiety-like behaviors by regulating the Warburg effect in microglia via PKM2

Neuroinflammation mediated by microglia is considered the primary cause and pathological process of anxiety. Abnormal glycolysis of microglia is observed during microglia activation. However, whether regulating the Warburg effect in microglia can effectively intervene anxiety and its potential mechanisms have not been elucidated. This study focused on coptisine (Cop), a natural alkaloid that regulates the glycolysis and function of microglia affecting anxiety. The effects of Cop on anxiety-like behaviors, hippocampal synaptic function, and excessive activation of microglia were assessed in lipopolysaccharide (LPS) induced mouse models of anxiety. Microglia expressing mutant pyruvate kinase isoform M2 (PKM2) were used to further investigate the molecular mechanism by which Cop regulates the phenotype of microglia. neuroinflammatory is emerging Further research revealed that Cop attaches to the amino acid residue phenylalanine 26 of PKM2, shifting the dynamic equilibrium of PKM2 towards tetramers, and enhancing its pyruvate kinase activity. This interaction prevented LPS-induced Warburg effect and inactivated PKM2/hypoxia-inducible factor-1α (HIF-1α) pathway in microglia. In conclusion, Cop attenuates anxiety by regulating the Warburg effect in microglia. Our work revealed the role of PKM2/(HIF-1α) pathway in anxiety for the first time. Importantly, the molecular mechanism by which Cop ameliorates anxiety-like behaviors is through modulation of the dimeric/tetrameric form of PKM2, indicating the usefulness of PKM2 as a key potential target for the treatment of anxiety.

Long non-coding RNAs and their role in breast cancer pathogenesis and drug resistance: Navigating the non-coding landscape review

Despite the progress made in the development of targeted therapies, breast cancer (BC) continues to pose a significant threat to the health of women. Transcriptomics has emerged due to the advancements in high-throughput sequencing technology. This provides crucial information about the role of non-coding RNAs (ncRNAs) in human cells, particularly long ncRNAs (lncRNAs), in disease development and function. When the control of these ncRNAs is disrupted, various illnesses emerge, including cancer. Numerous studies have produced empirical data on the function of lncRNAs in tumorigenesis and disease development. However, the roles and mechanisms of numerous lncRNAs remain unidentified at the molecular level because their regulatory role and the functional implications of abnormalities in cancer biology have yet to be thoroughly defined. The review gives an itemized summary of the most current developments in the role of lncRNA in BC, focusing on three main pathways, PI3K, MAPK, NF-kB, and hypoxia, and their resistance mechanisms.

Insights into the Molecular Mechanisms of Bushen Huoxue Decoction in Breast Cancer via Network Pharmacology and in vitro experiments

AIMS

Breast cancer (BC) is by far seen as the most common malignancy globally, with 2.261 million patients newly diagnosed, accounting for 11.7% of all cancer patients, according to the Global Cancer Statistics Report (2020). The luminal A subtype accounts for at least half of all BC diagnoses. According to TCM theory, Bushen Huoxue Decoction (BSHXD) is a prescription used for cancer treatment that may influence luminal A subtype breast cancer (LASBC).

OBJECTIVES

To analyze the clinical efficacy and underlying mechanisms of BSHXD in LASBC.

MATERIALS AND METHODS

Network pharmacology and in vitro experiments were utilized to foresee the underlying mechanism of BSHXD for LASBC.

RESULTS

According to the bioinformatics analysis, BSHXD induced several proliferation and apoptosis processes against LASBC, and the presumed targets of active components in BSHXD were mainly enriched in the HIF-1 and PI3K/AKT pathways. Flow cytometry assay and western blotting results revealed that the rate of apoptosis enhanced in a dose-dependent manner with BSHXD concentration increasing, respectively. BSHXD notably downregulated the expressions of HIF-1α, P-PI3K, PI3K, P-AKT and AKT proteins. However, adding an HIF-1α agonist restored those protein levels.

CONCLUSION

The study proved that the mechanism of BSHXD in LASBC may be connected to suppressing proliferation by inhibiting the activity of the HIF-1α/PI3K/AKT signaling pathway and promoting apoptosis via the Caspase cascade in LASBC cells.

Importance of long non-coding RNAs in the pathogenesis, diagnosis, and treatment of myocardial infarction

Myocardial infarction (MI), a major global cause of mortality and morbidity, continues to pose a significant burden on public health. Despite advances in understanding its pathogenesis, there remains a need to elucidate the intricate molecular mechanisms underlying MI progression. Long non-coding RNAs (lncRNAs) have emerged as key regulators in diverse biological processes, yet their specific roles in MI pathophysiology remain elusive. Conducting a thorough review of literature using PubMed and Google Scholar databases, we investigated the involvement of lncRNAs in MI, focusing on their regulatory functions and downstream signaling pathways. Our analysis revealed extensive dysregulation of lncRNAs in MI, impacting various biological processes through diverse mechanisms. Notably, lncRNAs act as crucial modulators of gene expression and signaling cascades, functioning as decoys, regulators, and scaffolds. Furthermore, studies identified the multifaceted roles of lncRNAs in modulating inflammation, apoptosis, autophagy, necrosis, fibrosis, remodeling, and ischemia-reperfusion injury during MI progression. Recent research highlights the pivotal contribution of lncRNAs to MI pathogenesis, offering novel insights into potential therapeutic interventions. Moreover, the identification of circulating lncRNA signatures holds promise for the development of non-invasive diagnostic biomarkers. In summary, findings underscore the significance of lncRNAs in MI pathophysiology, emphasizing their potential as therapeutic targets and diagnostic tools for improved patient management and outcomes.

Long non-coding RNAs: roles in cellular stress responses and epigenetic mechanisms regulating chromatin

Most of the genome is transcribed into RNA but only 2% of the sequence codes for proteins. Non-coding RNA transcripts include a very large number of long noncoding RNAs (lncRNAs). A growing number of identified lncRNAs operate in cellular stress responses, for example in response to hypoxia, genotoxic stress, and oxidative stress. Additionally, lncRNA plays important roles in epigenetic mechanisms operating at chromatin and in maintaining chromatin architecture. Here, we address three lncRNA topics that have had significant recent advances. The first is an emerging role for many lncRNAs in cellular stress responses. The second is the development of high throughput screening assays to develop causal relationships between lncRNAs across the genome with cellular functions. Finally, we turn to recent advances in understanding the role of lncRNAs in regulating chromatin architecture and epigenetics, advances that build on some of the earliest work linking RNA to chromatin architecture.

m6A-modified circCacna1c regulates necroptosis and ischemic myocardial injury by inhibiting Hnrnpf entry into the nucleus

BACKGROUND

Circular RNAs (circRNAs) are differentially expressed in various cardiovascular diseases, including myocardial infarction (MI) injury. However, their functional role in necroptosis-induced loss of cardiomyocytes remains unclear. We identified a cardiac necroptosis-associated circRNA transcribed from the Cacna1c gene (circCacna1c) to investigate the involvement of circRNAs in cardiomyocyte necroptosis.

METHODS

To investigate the role of circCacna1c during oxidative stress, H9c2 cells and neonatal rat cardiomyocytes were treated with hydrogen peroxide (H2O2) to induce reactive oxygen species (ROS)-induced cardiomyocyte death. The N6-methyladenosine (m6A) modification level of circCacna1c was determined by methylated RNA immunoprecipitation quantitative polymerase chain reaction (MeRIP-qPCR) analysis. Additionally, an RNA pull-down assay was performed to identify interacting proteins of circCacna1c in cardiomyocytes, and the regulatory role of circCacna1c in target protein expression was tested using a western blotting assay. Furthermore, the MI mouse model was constructed to analyze the effect of circCacna1c on heart function and cardiomyocyte necroptosis.

RESULTS

The expression of circCacna1c was found to be reduced in cardiomyocytes exposed to oxidative stress and in mouse hearts injured by MI. Overexpression of circCacna1c inhibited necroptosis of cardiomyocytes induced by hydrogen peroxide and MI injury, resulting in a significant reduction in myocardial infarction size and improved cardiac function. Mechanistically, circCacna1c directly interacts with heterogeneous nuclear ribonucleoprotein F (Hnrnpf) in the cytoplasm, preventing its nuclear translocation and leading to reduced Hnrnpf levels within the nucleus. This subsequently suppresses Hnrnpf-dependent receptor-interacting protein kinase 1 (RIPK1) expression. Furthermore, fat mass and obesity-associated protein (FTO) mediates demethylation of m6A modification on circCacna1c during necrosis and facilitates degradation of circCacna1c.

CONCLUSION

Our study demonstrates that circCacna1c can improve cardiac function following MI-induced heart injury by inhibiting the Hnrnpf/RIPK1-mediated cardiomyocyte necroptosis. Therefore, the FTO/circCacna1c/Hnrnpf/RIPK1 axis holds great potential as an effective target for attenuating cardiac injury caused by necroptosis in ischemic heart disease.

Hypoxia-inducible factors (HIFs) in early pregnancy: implications for miscarriage†

Miscarriage poses a significant threat to both maternal and fetal health. Its etiology remains unknown, and there are no established effective identification or prevention strategies. A low-oxygen environment in early pregnancy is a physiological necessity for embryonic and placental growth. Hypoxia-inducible factors are a family of classic hypoxia signaling molecules whose expression level may fluctuate abnormally because of an imbalance in oxygen levels. Its unusual fluctuations initiate multiple signaling pathways at the maternal womb. Hypoxia-inducible factors are a family of classic hypoxia-signaling molecules and immune tolerance. Notably, aberrant regulation of these processes may lead to miscarriage. This review aims to clarify how the hypoxia-inducible factor-1α mediates the aberrant regulation of biological processes, including autophagy, metabolic reprogramming, et al., and how these effects impact trophoblasts and other cells at the maternal-fetal interface. These findings provide new insights into potential therapeutic and preventive strategies for miscarriage.

LncRNAs in tumor metabolic reprogramming and tumor microenvironment remodeling

The tumor microenvironment (TME) is a complex and dynamic ecosystem composed of tumor cells, immune cells, supporting cells, and the extracellular matrix. Typically, the TME is characterized by an immunosuppressive state. To meet the demands of rapid proliferation, cancer cells undergo metabolic reprogramming, which enhances their biosynthesis and bioenergy supply. Immune cells require similar nutrients for activation and proliferation, leading to competition and immunosuppression within the TME. Additionally, tumor metabolites inhibit immune cell activation and function. Consequently, an immunosuppressed and immune-tolerant TME promotes cancer cell proliferation and metastasis. Long non-coding RNAs (lncRNAs), a category of non-coding RNA longer than 200 nucleotides, regulate tumor metabolic reprogramming by interacting with key enzymes, transporters, and related signaling pathways involved in tumor metabolism. Furthermore, lncRNAs can interact with both cellular and non-cellular components in the TME, thereby facilitating tumor growth, metastasis, drug resistance, and inducing immunosuppression. Recent studies have demonstrated that lncRNAs play a crucial role in reshaping the TME by regulating tumor metabolic reprogramming. In this discussion, we explore the potential mechanisms through which lncRNAs regulate tumor metabolic reprogramming to remodel the TME. Additionally, we examine the prospects of lncRNAs as targets for anti-tumor therapy and as biomarkers for tumor prognosis.

HIF-1α knockdown suppresses breast cancer metastasis via epithelial mesenchymal transition Abrogation

Lung metastasis, a leading cause of breast cancer mortality, lacks effective therapeutic options. Hypoxia-inducible factor 1-alpha (HIF-1α) plays important roles in breast cancer progression, but its direct impact on lung metastasis remains unclear. Herein, in this study, we investigated the role of HIF-1α in breast cancer lung metastasis and the potential of targeting it for therapeutic benefit. HIF-1α expression was knocked down in the 4T1 mouse mammary carcinoma cell line using a lentiviral vector. HIF-1α knockdown significantly reduced the migratory ability of 4T1 cells in vitro and lung metastasis in a mouse model. Mechanistically, HIF-1α knockdown decreased the expression of matrix metalloproteinases (MMP-2 and MMP-9) that degrade the extracellular matrix and suppressed the epithelial-to-mesenchymal transition (EMT) by increasing E-cadherin and decreasing vimentin expression. The findings of this study demonstrate that HIF-1α knockdown effectively inhibits lung metastasis of 4T1 cells both in vitro and in vivo by suppressing EMT. These results underscore a promising new approach for managing breast cancer metastasis.

Unraveling the role of HIF and epigenetic regulation in pulmonary arterial hypertension: implications for clinical research and its therapeutic approach

Pulmonary arterial hypertension (PAH) is characterized by pulmonary vascular remodeling with high pulmonary pressure, which ultimately leads to right heart failure and premature death. Emerging evidence suggests that both hypoxia and epigenetics play a pivotal role in the pathogenesis of PAH development. In this review article, we summarize the current developments in regulation of hypoxia inducible factor (HIF) isoforms in PAH vascular remodeling and the development of suitable animal models for discovery and testing of HIF pathway-targeting PAH therapeutics. In addition, we also discuss the epigenetic regulation of HIF-dependent isoforms in PAH and its therapeutic potential from a new perspective which highlights the importance of HIF isoform-specific targeting as a novel salutary strategy for PAH treatment.

Metabolic effects of quercetin on inflammatory and autoimmune responses in rheumatoid arthritis are mediated through the inhibition of JAK1/STAT3/HIF-1α signaling

BACKGROUND

Rheumatoid arthritis, a chronic autoimmune disease, is characterized by synovial hyperplasia and cartilage erosion. Here, we investigated the potential mechanism of action of quercetin, the main component of flavonoids, in treating rheumatoid arthritis.

OBJECT

To examine the anti-arthritic effects of quercetin and elucidate the specific mechanisms that differentiate its metabolic effects on autoimmune and inflammatory responses at the synovial cell level.

METHODS

We created a collagen-induced arthritis (CIA) model in Wistar rats, which were administered quercetin (50 or 100 mg/kg) continuously for four weeks via stomach perfusion. The arthritis score, histopathological staining, radiological assessment, and serum biochemical parameters were used to study the impact of quercetin on disease improvement. Additionally, immunofluorescence was employed to detect JAK1/STAT3/HIF-1α expression in rat joints. Moreover, the effects of quercetin (20, 40, and 80 µmol/L) on the properties and behavior of synovial fibroblasts were evaluated in an in vitro MH7A cell model using flow cytometry, CCK8, and transwell assays. Further, the mRNA expression levels of inflammatory cytokines IL1β, IL6, IL17, and TNFα were assessed by quantitative real-time PCR. Glucose, lactate, lactate dehydrogenase, pyruvate, pyruvate dehydrogenase, and adenosine triphosphate assay kits were employed to measure the metabolic effects of quercetin on synovial fibroblasts. Finally, immunoblotting was used to examine the impact of quercetin on the JAK1/STAT3/HIF-1α signaling pathway in synovial fibroblasts.

RESULTS

In vivo experiments confirmed the favorable effects of quercetin in CIA rats, including an improved arthritis score and reduced ankle bone destruction, in addition to a decrease in the pro-inflammatory cytokines IL-1β, IL-6, IL-17, and TNF-α in serum. Immunofluorescence verified that quercetin may ameliorate joint injury in rats with CIA by inhibiting JAK1/STAT3/HIF-1α signaling. Various in vitro experiments demonstrated that quercetin effectively inhibits IL-6-induced proliferation of MH7A cells and reduces their migratory and invasive behavior, while inducing apoptosis and reducing the expression of the pro-inflammatory cytokines IL1β, IL6, IL17, and TNFα at the mRNA level. Quercetin caused inhibition of glucose, lactate, lactate dehydrogenase, pyruvate, and adenosine triphosphate and increased pyruvate dehydrogenase expression in MH7A cells. It was further confirmed that quercetin may inhibit energy metabolism and inflammatory factor secretion in MH7A cells through JAK1/STAT3/HIF-1α signaling.

CONCLUSIONS

Quercetin's action on multiple target molecules and pathways makes it a promising treatment for cartilage injury in rheumatoid arthritis. By reducing joint inflammation, improving joint metabolic homeostasis, and decreasing immune system activation energy, quercetin inhibits the JAK1/STAT3/HIF-1α signaling pathway to improve disease status.

Replenishment of TCA cycle intermediates and long-noncoding RNAs regulation in breast cancer

The tricarboxylic acid (TCA) cycle is an essential interface that coordinates cellular metabolism and is as a primary route determining the fate of a variety of fuel sources, including glucose, fatty acid and glutamate. The crosstalk of nutrients replenished TCA cycle regulates breast cancer (BC) progression by changing substrate levels-induced epigenetic alterations, especially the methylation, acetylation, succinylation and lactylation. Long non-coding RNAs (lncRNA) have dual roles in inhibiting or promoting energy reprogramming, and so altering the metabolic flux of fuel sources to the TCA cycle, which may regulate epigenetic modifications at the cellular level of BC. This narrative review discussed the central role of the TCA cycle in interconnecting numerous fuels and the induced epigenetic modifications, and the underlying regulatory mechanisms of lncRNAs in BC.

Blocking the utilization of carbon sources via two pathways to induce tumor starvation for cancer treatment

Glucose oxidase (GOx) is often used to starvation therapy. However, only consuming glucose cannot completely block the energy metabolism of tumor cells. Lactate can support tumor cell survival in the absence of glucose. Here, we constructed a nanoplatform (Met@HMnO2-GOx/HA) that can deplete glucose while inhibiting the compensatory use of lactate by cells to enhance the effect of tumor starvation therapy. GOx can catalyze glucose into gluconic acid and H2O2, and then HMnO2 catalyzes H2O2 into O2 to compensate for the oxygen consumed by GOx, allowing the reaction to proceed sustainably. Furthermore, metformin (Met) can inhibit the conversion of lactate to pyruvate in a redox-dependent manner and reduce the utilization of lactate by tumor cells. Met@HMnO2-GOx/HA nanoparticles maximize the efficacy of tumor starvation therapy by simultaneously inhibiting cellular utilization of two carbon sources. Therefore, this platform is expected to provide new strategies for tumor treatment.

Non-metabolic enzyme function of pyruvate kinase M2 in breast cancer

Breast cancer (BC) is a prevalent malignant tumor in women, and its incidence has been steadily increasing in recent years. Compared with other types of cancer, it has the highest mortality and morbidity rates in women. So, it is crucial to investigate the underlying mechanisms of BC development and identify specific therapeutic targets. Pyruvate kinase M2 (PKM2), an important metabolic enzyme in glycolysis, has been found to be highly expressed in BC. It can also move to the nucleus and interact with various transcription factors and proteins, including hypoxia-inducible factor-1α (HIF-1α), signal transducer and activator of transcription 3 (STAT3), β-catenin, cellular-myelocytomatosis oncogene (c-Myc), nuclear factor kappa-light-chain enhancer of activated B cells (NF-κB), and mammalian sterile 20-like kinase 1 (MST1). This interaction leads to non-metabolic functions that control the cell cycle, proliferation, apoptosis, migration, invasion, angiogenesis, and tumor microenvironment in BC. This review provides an overview of the latest advancements in understanding the interactions between PKM2 and different transcription factors and proteins that influence the initiation and progression of BC. It also examined how natural drugs and noncoding RNAs affect various biological processes in BC cells through the regulation of the non-metabolic enzyme functions of PKM2. The findings provide valuable insights for improving the prognosis and developing targeted therapies for BC in the coming years.

Deciphering the Role of LncRNAs in Osteoarthritis: Inflammatory Pathways Unveiled

Long non-coding RNA (LncRNA), with transcripts over 200 nucleotides in length, play critical roles in numerous biological functions and have emerged as significant players in the pathogenesis of osteoarthritis (OA), an inflammatory condition traditionally viewed as a degenerative joint disease. This review comprehensively examines the influence of LncRNA on the inflammatory processes driving OA progression, focusing on their role in regulating gene expression, cellular activities, and inflammatory pathways. Notably, LncRNAs such as MALAT1, H19, and HOTAIR are upregulated in OA and exacerbate the inflammatory milieu by modulating key signaling pathways like NF-κB, TGF-β/SMAD, and Wnt/β-catenin. Conversely, LncRNA like MEG3 and GAS5, which are downregulated in OA, show potential in dampening inflammatory responses and protecting against cartilage degradation by influencing miRNA interactions and cytokine production. By enhancing our understanding of LncRNA' roles in OA inflammation, we can better leverage them as potential biomarkers for the disease and develop innovative therapeutic strategies for OA management. This paper aims to delineate the mechanisms by which LncRNA influence inflammatory responses in OA and propose them as novel targets for therapeutic intervention.

Targeting SNRNP200-induced splicing dysregulation offers an immunotherapy opportunity for glycolytic triple-negative breast cancer

Metabolic dysregulation is prominent in triple-negative breast cancer (TNBC), yet therapeutic strategies targeting cancer metabolism are limited. Here, utilizing multiomics data from our TNBC cohort (n = 465), we demonstrated widespread splicing deregulation and increased spliceosome abundance in the glycolytic TNBC subtype. We identified SNRNP200 as a crucial mediator of glucose-driven metabolic reprogramming. Mechanistically, glucose induces acetylation at SNRNP200 K1610, preventing its proteasomal degradation. Augmented SNRNP200 then facilitates splicing key metabolic enzyme-encoding genes (GAPDH, ALDOA, and GSS), leading to increased lactic acid and glutathione production. Targeting SNRNP200 with antisense oligonucleotide therapy impedes tumor metabolism and enhances the efficacy of anti-PD-1 therapy by activating intratumoral CD8+ T cells while suppressing regulatory T cells. Clinically, higher SNRNP200 levels indicate an inferior response to immunotherapy in glycolytic TNBCs. Overall, our study revealed the intricate interplay between RNA splicing and metabolic dysregulation, suggesting an innovative combination strategy for immunotherapy in glycolytic TNBCs.

Radiotherapy and breast cancer: finally, an lncRNA perspective on radiosensitivity and radioresistance

Radiotherapy (RT) serves as one of the key adjuvant treatments in management of breast cancer. Nevertheless, RT has two major problems: side effects and radioresistance. Given that patients respond differently to RT, it is imperative to understand the molecular mechanisms underlying these differences. Two-thirds of human genes do not encode proteins, as we have realized from genome-scale studies conducted after the advent of the genomic era; nevertheless, molecular understanding of breast cancer to date has been attained almost entirely based on protein-coding genes and their pathways. Long non-coding RNAs (lncRNAs) are a poorly understood but abundant class of human genes that yield functional non-protein-coding RNA transcripts. Here, we canvass the field to seek evidence for the hypothesis that lncRNAs contribute to radioresistance in breast cancer. RT-responsive lncRNAs ranging from "classical" lncRNAs discovered at the dawn of the post-genomic era (such as HOTAIR, NEAT1, and CCAT), to long intergenic lncRNAs such as LINC00511 and LINC02582, antisense lncRNAs such as AFAP-AS1 and FGD5-AS1, and pseudogene transcripts such as DUXAP8 were found during our screen of the literature. Radiation-related pathways modulated by these lncRNAs include DNA damage repair, cell cycle, cancer stem cells phenotype and apoptosis. Thus, providing a clear picture of these lncRNAs' underlying RT-relevant molecular mechanisms should help improve overall survival and optimize the best radiation dose for each individual patient. Moreover, in healthy humans, lncRNAs show greater natural expression variation than protein-coding genes, even across individuals, alluding to their exceptional potential for targeting in truly personalized, precision medicine.

TCEB2/HIF1A signaling axis promotes chemoresistance in ovarian cancer cells by enhancing glycolysis and angiogenesis

Ovarian cancer is an extremely malignant gynaecological tumour with a poor patient prognosis and is often associated with chemoresistance. Thus, exploring new therapeutic approaches to improving tumour chemosensitivity is important. The expression of transcription elongation factor B polypeptide 2 (TCEB2) gene is reportedly upregulated in ovarian cancer tumour tissues with acquired resistance, but the specific mechanism involved in tumour resistance remains unclear. In this study, we found that TCEB2 was abnormally highly expressed in cisplatin-resistant tumour tissues and cells. TCEB2 silencing also inhibited the growth and glycolysis of SKOV-3/cisplatin (DDP) and A2780/DDP cells. We further incubated human umbilical vein endothelial cells (HUVECs) with culture supernatants from cisplatin-resistant cells having TCEB2 knockdown. Results revealed that the migration, invasion, and angiogenesis of HUVECs were significantly inhibited. Online bioinformatics analysis revealed that the hypoxia-inducible factor-1A (HIF-1A) protein may bind to TCEB2, and TCEB2 silencing inhibited SKOV-3/DDP cell growth and glycolysis by downregulating HIF1A expression. Similarly, TCEB2 promoted HUVEC migration, invasion, and angiogenesis by upregulating HIF1A expression. In vivo experiments showed that TCEB2 silencing enhanced the sensitivity of ovarian cancer nude mice to cisplatin and that TCEB2 knockdown inhibited the glycolysis and angiogenesis of tumour cells. Our findings can serve as a reference for treating chemoresistant ovarian cancer.

PAF1/HIF1α axis rewires the glycolytic metabolism to fuel aggressiveness of pancreatic cancer

BACKGROUND

PAF1/PD2 deregulation contributes to tumorigenesis, drug resistance, and cancer stem cell maintenance in Pancreatic Cancer (PC). Recent studies demonstrate that metabolic reprogramming plays a role in PC progression, but the mechanism is poorly understood. Here, we focused on examining the role of PAF1/PD2 in the metabolic rewiring of PC.

METHODS

Cell lines were transfected with shRNAs to knockdown PAF1/PD2. Metabolic genes regulated by PAF1/PD2 were identified by qPCR/western blot, and metabolic assays were performed. Immunoprecipitations/ChIP were performed to identify PAF1/PD2 protein partners and confirm PAF1/HIF1α sub-complex binding to LDHA.

RESULTS

PAF1 and LDHA showed progressively increased expression in human pancreatic tumor sections. Aerobic glycolysis genes were downregulated in PAF1-depleted PC cells. Metabolic assays indicated a decreased lactate production and glucose uptake in knockdown cells. Furthermore, PAF1/PD2 depletion showed a reduced glycolytic rate and increased oxidative phosphorylation by ECAR and OCR analysis. Interestingly, we identified that HIF1α interacts and co-localizes with PAF1, specifically in PC cells. We also observed that the PAF1/PD2-HIF1α complex binds to the LDHA promoter to regulate its expression, reprogramming the metabolism to utilize the aerobic glycolysis pathway preferentially.

CONCLUSION

Overall, the results indicate that PAF1/PD2 rewires PC metabolism by interacting with HIF1α to regulate the expression of LDHA.

Fundamentals of redox regulation in biology

Oxidation-reduction (redox) reactions are central to the existence of life. Reactive species of oxygen, nitrogen and sulfur mediate redox control of a wide range of essential cellular processes. Yet, excessive levels of oxidants are associated with ageing and many diseases, including cardiological and neurodegenerative diseases, and cancer. Hence, maintaining the fine-tuned steady-state balance of reactive species production and removal is essential. Here, we discuss new insights into the dynamic maintenance of redox homeostasis (that is, redox homeodynamics) and the principles underlying biological redox organization, termed the 'redox code'. We survey how redox changes result in stress responses by hormesis mechanisms, and how the lifelong cumulative exposure to environmental agents, termed the 'exposome', is communicated to cells through redox signals. Better understanding of the molecular and cellular basis of redox biology will guide novel redox medicine approaches aimed at preventing and treating diseases associated with disturbed redox regulation.

Oxidative stress-mediated epigenetic remodeling, metastatic progression and cell signaling in cancer

Cancer is a serious public health issue and cases are rising at a high rate around the world. Altered production of reactive oxygen species (ROS) causes oxidative stress (OS) which plays a vital role in cancer development by disrupting signaling pathways and genomic integrity in the cellular microenvironment. In this study, we reviewed the regulation of noncoding RNAs, histone modifications, and DNA methylation which OS is involved in. These mechanisms promote cancer growth, metastasis, and resistance to chemotherapeutic agents. There is significant potential to improve patient outcomes through the development of customized medications and interventions that precisely address the role of OS in the onset and progression of cancer. Redox-modulating drugs, antioxidant-based therapies, and measures to restore regular cellular activity and OS-modulated signaling pathways are some examples of these strategies. One other hypothesis rationalizes the cancer-suppressing effect of OS, which acts as a two-edged condition that warns against the use of antioxidants for cancer treatment and management. The present study was executed to review the impact of OS on epigenetic machinery, the evolution of metastatic cancer, and how OS mediates cellular signaling. Along with, insights into the potential of targeting OS-mediated mechanisms for cancer therapy.

Exosomal circ-0100519 promotes breast cancer progression via inducing M2 macrophage polarisation by USP7/NRF2 axis

BACKGROUND

Breast cancer (BC) is one of the most prevalent malignant tumours that threatens women health worldwide. It has been reported that circular RNAs (circRNAs) play an important role in regulating tumour progression and tumour microenvironment (TME) remodelling.

METHODS

Differentially expression characteristics and immune correlations of circRNAs in BC were verified using high-throughput sequencing and bioinformatic analysis. Exosomes were characterised by nanoparticle transmission electron microscopy and tracking analysis. The biological function of circ-0100519 in BC development was demonstrated both in vitro and in vivo. Western blotting, RNA pull-down, RNA immunoprecipitation, flow cytometry, and luciferase reporter were conducted to investigate the underlying mechanism.

RESULTS

Circ-0100519 was significant abundant in BC tumour tissues and related to poor prognosis. It can be encapsulated into secreted exosomes, thereby promoting BC cell invasion and metastasis via inducing M2-like macrophages polarisation.Mechanistically, circ-0100519 acted as a scaffold to enhance the interaction between the deubiquitinating enzyme ubiquitin-specific protease 7 (USP7) and nuclear factor-like 2 (NRF2) in macrophages, inducing the USP7-mediated deubiquitination of NRF2. Additionally, HIF-1α could function as an upstream effector to enhance circ-0100519 transcription.

CONCLUSIONS

Our study revealed that exosomal circ-0100519 is a potential biomarker for BC diagnosis and prognosis, and the HIF-1α inhibitor PX-478 may provide a therapeutic target for BC.

Understanding Hypoxia-Driven Tumorigenesis: The Interplay of HIF1A, DNA Methylation, and Prolyl Hydroxylases in Head and Neck Squamous Cell Carcinoma

Hypoxia-inducible factor 1-alpha (HIF1A) is a key transcription factor aiding tumor cells' adaptation to hypoxia, regulated by the prolyl hydroxylase family (EGLN1-3) by directing toward degradation pathways. DNA methylation potentially influences EGLN and HIF1A levels, impacting cellular responses to hypoxia. We examined 96 HNSCC patients and three cell lines, analyzing gene expression of EGLN1-3, HIF1A, CA9, VEGF, and GLUT1 at the mRNA level and EGLN1 protein levels. Methylation levels of EGLNs and HIF1A were assessed through high-resolution melting analysis. Bioinformatics tools were employed to characterize associations between EGLN1-3 and HIF1A expression and methylation. We found significantly higher mRNA levels of EGLN3, HIF1A, GLUT1, VEGF, and CA9 (p = 0.021; p < 0.0001; p < 0.0001; p = 0.004, and p < 0.0001, respectively) genes in tumor tissues compared to normal ones and downregulation of the EGLN1 mRNA level in tumor tissues (p = 0.0013). In HNSCC patients with hypermethylation of HIF1A in normal tissue, we noted a reduction in HIF1A mRNA levels compared to tumor tissue (p = 0.04). In conclusion, the differential expression of EGLN and HIF1A genes in HNSCC tumors compared to normal tissues influences patients' overall survival, highlighting their role in tumor development. Moreover, DNA methylation could be responsible for HIF1A suppression in the normal tissues of HNSCC patients.

Endothelial EGLN3-PKM2 signaling induces the formation of acute astrocytic barrier to alleviate immune cell infiltration after subarachnoid hemorrhage

BACKGROUND

Most subarachnoid hemorrhage (SAH) patients have no obvious hematoma lesions but exhibit blood-brain barrier dysfunction and vasogenic brain edema. However, there is a few days between blood‒brain barrier dysfunction and vasogenic brain edema. The present study sought to investigate whether this phenomenon is caused by endothelial injury induced by the acute astrocytic barrier, also known as the glial limitans.

METHODS

Bioinformatics analyses of human endothelial cells and astrocytes under hypoxia were performed based on the GEO database. Wild-type, EGLN3 and PKM2 conditional knock-in mice were used to confirm glial limitan formation after SAH. Then, the effect of endothelial EGLN3-PKM2 signaling on temporal and spatial changes in glial limitans was evaluated in both in vivo and in vitro models of SAH.

RESULTS

The data indicate that in the acute phase after SAH, astrocytes can form a temporary protective barrier, the glia limitans, around blood vessels that helps maintain barrier function and improve neurological prognosis. Molecular docking studies have shown that endothelial cells and astrocytes can promote glial limitans-based protection against early brain injury through EGLN3/PKM2 signaling and further activation of the PKC/ERK/MAPK signaling pathway in astrocytes after SAH.

CONCLUSION

Improving the ability to maintain glial limitans may be a new therapeutic strategy for improving the prognosis of SAH patients.

The regulation of hypoxia-related lncRNAs in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is still a public health disease with its high prevalence and morbidity. Short of early diagnosis biomarkers and effective therapy, the treatment of HCC patients hasn't achieved ideal effect. Hypoxia is a hallmark of HCC, which is mainly induced by imbalance of tumor cell proliferation and insufficient supply of oxygen. Recently, amounting evidence suggested lncRNAs, especially hypoxia-related lncRNAs play a pivotal role in regulating HCC. Hypoxia-related lncRNAs are involved in altering glucose metabolism, maintaining of cancer stem cell-like properties (CSCs), cell apotosis, proliferation and immune escape, which all contribute to the poor prognosis of HCC patients. The novel identified hypoxia-related lncRNAs could be the potential target or biomarkers of HCC, which are beneficial to the clinical treatment. Herein, we summarized currently reported hypoxia-related lncRNAs and their related mechanisms, providing potential application and future perspective of hypoxia-related lncRNAs as a potential therapeutic target.

Ginsenoside Rh2 shifts tumor metabolism from aerobic glycolysis to oxidative phosphorylation through regulating the HIF1-α/PDK4 axis in non-small cell lung cancer

BACKGROUND

Ginsenoside Rh2 (G-Rh2), a steroidal compound extracted from roots of ginseng, has been extensively studied in tumor therapy. However, its specific regulatory mechanism in non-small cell lung cancer (NSCLC) is not well understood. Pyruvate dehydrogenase kinase 4 (PDK4), a central regulator of cellular energy metabolism, is highly expressed in various malignant tumors. We investigated the impact of G-Rh2 on the malignant progression of NSCLC and how it regulated PDK4 to influence tumor aerobic glycolysis and mitochondrial function.

METHOD

We examined the inhibitory effect of G-Rh2 on NSCLC through I proliferation assay, migration assay and flow cytometry in vitro. Subsequently, we verified the ability of G-Rh2 to inhibit tumor growth and metastasis by constructing subcutaneous tumor and metastasis models in nude mice. Proteomics analysis was conducted to analyze the action pathways of G-Rh2. Additionally, we assessed glycolysis and mitochondrial function using seahorse, PET-CT, Western blot, and RT-qPCR.

RESULT

Treatment with G-Rh2 significantly inhibited tumor proliferation and migration ability both in vitro and in vivo. Furthermore, G-Rh2 inhibited the tumor's aerobic glycolytic capacity, including glucose uptake and lactate production, through the HIF1-α/PDK4 pathway. Overexpression of PDK4 demonstrated that G-Rh2 targeted the inhibition of PDK4 expression, thereby restoring mitochondrial function, promoting reactive oxygen species (ROS) accumulation, and inducing apoptosis. When combined with sodium dichloroacetate, a PDK inhibitor, it complemented the inhibitory capacity of PDKs, acting synergistically as a detoxifier.

CONCLUSION

G-Rh2 could target and down-regulate the expression of HIF-1α, resulting in decreased expression of glycolytic enzymes and inhibition of aerobic glycolysis in tumors. Additionally, by directly targeting mitochondrial PDK, it elevated mitochondrial oxidative phosphorylation and enhanced ROS accumulation, thereby promoting tumor cells to undergo normal apoptotic processes.

Metabolism-regulating non-coding RNAs in breast cancer: roles, mechanisms and clinical applications

Breast cancer is one of the most common malignancies that pose a serious threat to women's health. Reprogramming of energy metabolism is a major feature of the malignant transformation of breast cancer. Compared to normal cells, tumor cells reprogram metabolic processes more efficiently, converting nutrient supplies into glucose, amino acid and lipid required for malignant proliferation and progression. Non-coding RNAs(ncRNAs) are a class of functional RNA molecules that are not translated into proteins but regulate the expression of target genes. NcRNAs have been demonstrated to be involved in various aspects of energy metabolism, including glycolysis, glutaminolysis, and fatty acid synthesis. This review focuses on the metabolic regulatory mechanisms and clinical applications of metabolism-regulating ncRNAs involved in breast cancer. We summarize the vital roles played by metabolism-regulating ncRNAs for endocrine therapy, targeted therapy, chemotherapy, immunotherapy, and radiotherapy resistance in breast cancer, as well as their potential as therapeutic targets and biomarkers. Difficulties and perspectives of current targeted metabolism and non-coding RNA therapeutic strategies are discussed.

Non-coding RNAs and exosomal non-coding RNAs in diabetic retinopathy: A narrative review

Diabetic retinopathy (DR) is a devastating complication of diabetes, having extensive and resilient effects on those who suffer from it. As yet, the underlying cell mechanisms of this microvascular disorder are largely unclear. Recently, growing evidence suggests that epigenetic mechanisms can be responsible for gene deregulation leading to the alteration of key processes in the development and progression of DR, in addition to the widely recognized pathological mechanisms. It is noteworthy that seemingly unending epigenetic modifications, caused by a prolonged period of hyperglycemia, may be a prominent factor that leads to metabolic memory, and brings epigenetic entities such as non-coding RNA into the equation. Consequently, further investigation is necessary to truly understand this mechanism. Exosomes are responsible for carrying signals from cells close to the vasculature that are participating in abnormal signal transduction to faraway organs and cells by sailing through the bloodstream. These signs indicate metabolic disorders. With the aid of their encased structure, they can store diverse signaling molecules, which then can be dispersed into the blood, urine, and tears. Herein, we summarized various non-coding RNAs (ncRNAs) that are related to DR pathogenesis. Moreover, we highlighted the role of exosomal ncRNAs in this disease.

LncRNA LY6E-DT and its encoded metastatic-related protein play oncogenic roles via different pathways and promote breast cancer progression

Abnormal long noncoding RNA (lncRNA) expression plays an important role in tumor invasion and metastasis. Here, we show that lncRNA LY6E divergent transcript (LY6E-DT) levels are increased in breast cancer (BC) tissues. Transcription factor SP3 binds directly to the LY6E-DT promoter, activating its transcription. Moreover, LY6E-DT N6-methyladenosine modification by methyltransferase-like protein 14 (METTL14) promotes its expression, dependent on the "reader" insulin-like growth factor 2 mRNA binding protein 1(IGF2BP1)-dependent pathway. Notably, we discovered that the lncRNA LY6E-DT encodes a conserved 153-aa protein, "Metastatic-Related Protein" (MRP). Both LY6E-DT and MRP promote BC invasion and metastasis, and MRP expression could distinguish BC patients with lymph node metastasis from those without. Mechanistically, MRP binds heterogeneous nuclear ribonucleoproteins C1/C2 (HNRNPC), enhancing the interaction between HNRNPC and epidermal growth factor receptor (EGFR) mRNA, increasing EGFR mRNA stability and protein expression and subsequently activating the phosphatidylinositol 3‑kinase/protein kinase B signaling (PI3K) pathway. LncRNA LY6E-DT promotes the interaction between Y box binding protein 1 (YBX1) and importin α1 and increases YBX1 protein entry into the nucleus, where it transcriptionally activates zinc finger E-box-binding homeobox 1(ZEB1). Our findings uncover a novel regulatory mechanism underlying BC invasion orchestrated by LY6E-DT and its encoded MRP.

HIF-1α regulates the cell viability in radioiodine-resistant papillary thyroid carcinoma cells induced by hypoxia through PKM2/NF-κB signaling pathway

The curative treatment options for papillary thyroid cancer (PTC) encompass surgical intervention, radioactive iodine administration, and chemotherapy. However, the challenges of radioiodine (RAI) resistance, metastasis, and chemotherapy resistance remain inadequately addressed. The objective of this study was to investigate the protective role of hypoxia-inducible factor-1α (HIF-1α) in 131 I-resistant cells and a xenograft model under hypoxic conditions, as well as to explore potential mechanisms. The effects of HIF-1α on 131 I-resistant BCPAP and TPC-1 cells, as well as the xenograft model, were assessed in this study. Cell viability, migration, invasion, and apoptosis rates were measured using Cell Counting Kit-8, wound-healing, Transwell, and flow cytometry assays. Additionally, the expressions of Ki67, matrix metalloproteinase-9 (MMP-9), and pyruvate kinase M2 (PKM2) were examined using immunofluorescence or immunohistochemistry assays. Sodium iodide symporter and PKM2/NF-κBp65 relative protein levels were detected by western blot analysis. The findings of our study indicate that siHIF-1α effectively inhibits cell proliferation, cell migration, and invasion in 131 I-resistant cells under hypoxic conditions. Additionally, the treatment of siHIF-1α leads to alterations in the relative protein levels of Ki67, MMP-9, PKM2, and PKM2/NF-κBp65, both in vivo and in vitro. Notably, the effects of siHIF-1α are modified when DASA-58, an activator of PKM2, is administered. These results collectively demonstrate that siHIF-1α reduces cell viability in PTC cells and rat models, while also mediating the nuclear factor-κB (NF-κB)/PKM2 signaling pathway. Our findings provide a new rationale for further academic and clinical research on RAI-resistant PTC.

Advances in RNA therapeutics for modulation of 'undruggable' targets

Over the past decades, drug discovery utilizing small pharmacological compounds, fragment-based therapeutics, and antibody therapy have significantly advanced treatment options for many human diseases. However, a major bottleneck has been that>70% of human proteins/genomic regions are 'undruggable' by the above-mentioned approaches. Many of these proteins constitute essential drug targets against complex multifactorial diseases like cancer, immunological disorders, and neurological diseases. Therefore, alternative approaches are required to target these proteins or genomic regions in human cells. RNA therapeutics is a promising approach for many of the traditionally 'undruggable' targets by utilizing methods such as antisense oligonucleotides, RNA interference, CRISPR/Cas-based genome editing, aptamers, and the development of mRNA therapeutics. In the following chapter, we will put emphasis on recent advancements utilizing these approaches against challenging drug targets, such as intranuclear proteins, intrinsically disordered proteins, untranslated genomic regions, and targets expressed in inaccessible tissues.

Glucose Deprivation Promotes Pseudohypoxia and Dedifferentiation in Lung Adenocarcinoma

Increased utilization of glucose is a hallmark of cancer. Sodium-glucose transporter 2 (SGLT2) is a critical player in glucose uptake in early-stage and well-differentiated lung adenocarcinoma (LUAD). SGLT2 inhibitors, which are FDA approved for diabetes, heart failure, and kidney disease, have been shown to significantly delay LUAD development and prolong survival in murine models and in retrospective studies in diabetic patients, suggesting that they may be repurposed for lung cancer. Despite the antitumor effects of SGLT2 inhibition, tumors eventually escape treatment. Here, we studied the mechanisms of resistance to glucose metabolism-targeting treatments. Glucose restriction in LUAD and other tumors induced cancer cell dedifferentiation, leading to a more aggressive phenotype. Glucose deprivation caused a reduction in alpha-ketoglutarate (αKG), leading to attenuated activity of αKG-dependent histone demethylases and histone hypermethylation. The dedifferentiated phenotype depended on unbalanced EZH2 activity that suppressed prolyl-hydroxylase PHD3 and increased expression of hypoxia-inducible factor 1α (HIF1α), triggering epithelial-to-mesenchymal transition. Finally, a HIF1α-dependent transcriptional signature of genes upregulated by low glucose correlated with prognosis in human LUAD. Overall, this study furthers current knowledge of the relationship between glucose metabolism and cell differentiation in cancer, characterizing the epigenetic adaptation of cancer cells to glucose deprivation and identifying targets to prevent the development of resistance to therapies targeting glucose metabolism.

SIGNIFICANCE

Epigenetic adaptation allows cancer cells to overcome the tumor-suppressive effects of glucose restriction by inducing dedifferentiation and an aggressive phenotype, which could help design better metabolic treatments.

Tumour circular RNAs elicit anti-tumour immunity by encoding cryptic peptides

Emerging data have shown that previously defined noncoding genomes might encode peptides that bind human leukocyte antigen (HLA) as cryptic antigens to stimulate adaptive immunity1,2. However, the significance and mechanisms of action of cryptic antigens in anti-tumour immunity remain unclear. Here mass spectrometry of the HLA class I (HLA-I) peptidome coupled with ribosome sequencing of human breast cancer samples identified HLA-I-binding cryptic antigenic peptides that were noncanonically translated by a tumour-specific circular RNA (circRNA): circFAM53B. The cryptic peptides efficiently primed naive CD4+ and CD8+ T cells in an antigen-specific manner and induced anti-tumour immunity. Clinically, the expression of circFAM53B and its encoded peptides was associated with substantial infiltration of antigen-specific CD8+ T cells and better survival in patients with breast cancer and patients with melanoma. Mechanistically, circFAM53B-encoded peptides had strong binding affinity to both HLA-I and HLA-II molecules. In vivo, administration of vaccines consisting of tumour-specific circRNA or its encoded peptides in mice bearing breast cancer tumours or melanoma induced enhanced infiltration of tumour-antigen-specific cytotoxic T cells, which led to effective tumour control. Overall, our findings reveal that noncanonical translation of circRNAs can drive efficient anti-tumour immunity, which suggests that vaccination exploiting tumour-specific circRNAs may serve as an immunotherapeutic strategy against malignant tumours.

The nexus of long noncoding RNAs, splicing factors, alternative splicing and their modulations

The process of alternative splicing (AS) is widely deregulated in a variety of cancers. Splicing is dependent upon splicing factors. Recently, several long noncoding RNAs (lncRNAs) have been shown to regulate AS by directly/indirectly interacting with splicing factors. This review focuses on the regulation of AS by lncRNAs through their interaction with splicing factors. AS mis-regulation caused by either mutation in splicing factors or deregulated expression of splicing factors and lncRNAs has been shown to be involved in cancer development and progression, making aberrant splicing, splicing factors and lncRNA suitable targets for cancer therapy. This review also addresses some of the current approaches used to target AS, splicing factors and lncRNAs. Finally, we discuss research challenges, some of the unanswered questions in the field and provide recommendations to advance understanding of the nexus of lncRNAs, AS and splicing factors in cancer.

PTCSC3, XIST, GAS5, UCA1, and HIFAL: Five lncRNAs Emerging as Potential Prognostic Players in Egyptian Adult Acute Myeloid Leukemia (AML) Patients

BACKGROUND AND AIMS

So far, long noncoding RNAs (lncRNAs) signatures in acute myeloid leukemia (AML) are poorly understood. The present study aims to explore the prognostic significance of eleven cancer-related lncRNAs in bone marrow (BM) samples from adult Egyptian AML patients.

MATERIALS AND METHODS

In this study, we analyzed eleven lncRNAs using the qRT-PCR assay in the bone marrow (BM) of 79 de novo AML adult patients before receiving any therapy.

RESULTS

Five lncRNAs out of 11 were aberrantly expressed, and two lncRNAs influenced significantly the patient's overall survival (OS). LncRNA-XIST was favorable when overexpressed (in univariate and multivariate analysis, P-value = .001). LncRNA-GAS5 adversely affected the OS (only in multivariate analysis P-value = .02). Two other lncRNAs (UCA1 and HIFAL) impacted complete remission induction (CR) significantly in univariate analysis (P-value = .046 for both). Furthermore, lncRNA-UCA1 affected CR significantly in multivariate COX regression analysis (P-value = .004). The 4 previously mentioned lncRNAs were among the 9 downregulated lncRNAs. Instead, the only 2 upregulated lncRNAs (SNHG15, MALAT1) did not significantly influence neither CR induction nor OS. LncRNA-PTCSC3, a fifth lncRNA, emerged as the only one that could predict relapse occurrence in an upfront original BM sample.

CONCLUSION

Two lncRNAs out of eleven (lncRNA-XIST and GAS5) impacted OS, and two other lncRNAs (UCA1 and HIFAL) affected CR in adult de novo AML patients. LncRNA-PTCSC3 predict relapse, however, further validation is still required.

Glucocorticoid receptors involved in ginsenoside compound K ameliorate adjuvant arthritis by inhibiting the glycolysis of fibroblast-like synoviocytes via the NF-κB/HIF-1α pathway

CONTEXT

Ginsenoside metabolite compound K (CK) is an active metabolite produced by ginsenosides in vivo that has an anti-arthritic effect related to the glucocorticoid receptor (GR). However, the potential mechanisms of CK remain unclear.

OBJECTIVE

This study explores the role and potential mechanisms of CK in vivo and in vitro.

MATERIALS AND METHODS

Adjuvant arthritis (AA) model was induced in Sprague-Dawley (SD) rats; the rats were randomly divided into four groups (n = 10): normal, AA, CK (80 mg/kg), and dexamethasone (Dex) group (1 mg/kg). From day 15, rats were treated with CK (once a day, i.g.) and Dex (once every 3 days, i.p.) for 18 days. To further verify the mechanism of CK, fibroblast-like synoviocytes (FLS) were stimulated by tumour necrosis factor α (TNF-α) to establish an inflammatory model in vitro.

RESULTS

CK (80 mg/kg) reduced paw swelling (52%) and arthritis global assessment (31%) compared to that in AA rats. In addition, CK (80 mg/kg) suppressed GLUT1 (38%), HK2 (50%), and PKM2 (56%) levels compared with those in AA FLS. However, the effects of CK (30 μM) on these events were weakened or enhanced after GR knockdown or overexpression in FLS stimulated by TNF-α (30 ng/mL). CK (80 mg/kg) also downregulated the expression of P65 (61%), p-IκB (92%), and HIF-1α (59%).

DISCUSSION AND CONCLUSIONS

The inhibition of CK on glycolysis and the NF-κB/HIF-1α pathway is potentially mediated through activating GR. These findings provide experimental evidence for elucidating the molecular mechanism of CK in treating rheumatoid arthritis (RA).

The role of noncoding RNAs in the tumor microenvironment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the leading fatal malignancy worldwide. The tumor microenvironment (TME) can affect the survival, proliferation, migration, and even dormancy of cancer cells. Hypoxia is an important component of the TME, and hypoxia-inducible factor-1α (HIF-1α) is the most important transcriptional regulator. Noncoding RNAs (ncRNAs), including microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs), comprise a large part of the human transcriptome and play an important role in regulating the tumorigenesis of HCC. This review discusses the role of ncRNAs in hepatocarcinogenesis, epithelial-mesenchymal transition (EMT), and angiogenesis in a hypoxic microenvironment, as well as the interactions between ncRNAs and key components of the TME. It further discusses their use as biomarkers and the potential clinical value of drugs, as well as the challenges faced in the future.

HILPS, a long noncoding RNA essential for global oxygen sensing in humans

Adaptation to low levels of oxygen (hypoxia) is a universal biological feature across metazoans. However, the unique mechanisms how different species sense oxygen deprivation remain unresolved. Here, we functionally characterize a novel long noncoding RNA (lncRNA), LOC105369301, which we termed hypoxia-induced lncRNA for polo-like kinase 1 (PLK1) stabilization (HILPS). HILPS exhibits appreciable basal expression exclusively in a wide variety of human normal and cancer cells and is robustly induced by hypoxia-inducible factor 1α (HIF1α). HILPS binds to PLK1 and sequesters it from proteasomal degradation. Stabilized PLK1 directly phosphorylates HIF1α and enhances its stability, constituting a positive feed-forward circuit that reinforces oxygen sensing by HIF1α. HILPS depletion triggers catastrophic adaptation defect during hypoxia in both normal and cancer cells. These findings introduce a mechanism that underlies the HIF1α identity deeply interconnected with PLK1 integrity and identify the HILPS-PLK1-HIF1α pathway as a unique oxygen-sensing axis in the regulation of human physiological and pathogenic processes.

Implications of different cell death patterns for prognosis and immunity in lung adenocarcinoma

In recent years, lung adenocarcinoma (LUAD) has become a focus of attention due to its low response to treatment, poor prognosis, and lack of reliable indicators to predict the progression or therapeutic effect of LUAD. Different cell death patterns play a crucial role in tumor development and are promising for predicting LUAD prognosis. From the TCGA and GEO databases, we obtained bulk transcriptomes, single-cell transcriptomes, and clinical information. Genes in 15 types of cell death were analyzed for cell death index (CDI) signature establishment. The CDI signature using necroptosis + immunologic cell death-related genes was established in the TCGA cohort with the 1-, 2-, 3-, 4- and 5-year AUC values were 0.772, 0.736, 0.723, 0.795, and 0.743, respectively. The prognosis was significantly better in the low CDI group than in the high CDI group. We also investigated the relationship between the CDI signature and clinical variables, published prognosis biomarkers, immune cell infiltration, functional enrichment pathways, and immunity biomarkers. In vitro assay showed that HNRNPF and FGF2 promoted lung cancer cell proliferation and migration and were also involved in cell death. Therefore, as a robust prognosis biomarker, CDI signatures can screen for patients who might benefit from immunotherapy and improve diagnostic accuracy and LUAD patient outcomes.