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This study aimed to investigate the efficiency of the secondary metabolites (SMs) produced by a co-culture of Trichoderma harzianum TW21990 and Burkholderia vietnamiensis B418 in the control of Colletotrichum siamense CM9. A fermentation filtrate of B418 + TW21990 co-culture (BT21) produced a notable increase in the inhibition rate of CM9 compared to those of TW21990 and B418 monocultures, which reached 91.40% and 80.46% on PDA plates and strawberry leaves, respectively. The BT21 fermentation broth exhibited high control efficiency on strawberry root rot of 68.95% in a pot experiment, which was higher than that in the monocultures and fluazinam treatment. In addition, BT21 treatment promoted strawberry root development, improved antioxidative enzyme activities in the leaves and roots, and enhanced the total chlorophyll content of the strawberry leaves. UHPLC-MS/MS analysis of fermentation filtrates was performed to elucidate SM variations, revealing 478 and 795 metabolites in BT21 co-culture in positive and negative ion modes, respectively. The metabolomic profiles suggested abundant SMs with antagonistic capabilities and growth-promoting effects: 3-(propan-2-yl)-octahydropyrrolo [1,2-a]pyrazine-1,4-dione (cyclo(L-Pro-L-Val)), 3-[(4-hydroxyphenyl)methyl]-octahydropyrrolo[1,2-a]pyrazine-1,4-dione (cyclo(L-Pro-L-Tyr)), 3-indoleacetic acid (IAA), 2-hydroxycinnamic acid, 4-aminobutyric acid (GABA), bafilomycin B1, and DL-indole-3-lactic acid (ILA) were significantly enhanced in the co-culture. Overall, this study demonstrates that a co-culture strategy is efficient for inducing bioactive SMs in T. harzianum and B. vietnamiensis, which could be exploited as a novel approach for developing biocontrol consortia.
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OBJECTIVE: This study aimed to investigate the potential involvement of vasoactive intestinal polypeptide (VIP) in myopia development and its contribution to the mechanism of action of the anti-myopia drug, atropine. METHODS: Thirty-three-week-old guinea pigs were randomly divided into normal control (NC, n = 10), monocularly form-deprived (FDM, n = 10), and FDM treated with 1% atropine (FDM + AT, n = 10) groups. The diopter and axial length were measured at 0, 2, and 4 weeks. Guinea pig eyeballs were removed at week four, fixed, and stained for morphological changes. Immunohistochemistry (IHC) and in situ hybridization (ISH) were performed to evaluate VIP protein and mRNA levels. RESULTS: The FDM group showed an apparent myopic shift compared to the control group. The results of the H&E staining were as follows: the cells of the inner/outer nuclear layers and retinal ganglion cells were disorganized; the choroidal thickness (ChT), blood vessel lumen, and area were decreased; the sclera was thinner, with disordered fibers and increased interfibrillar space. IHC and ISH revealed that VIP's mRNA and protein expressions were significantly up-regulated in the retina of the FDM group. Atropine treatment attenuated FDM-induced myopic shift and fundus changes, considerably reducing VIP's mRNA and protein expressions. CONCLUSIONS: The findings of elevated VIP mRNA and protein levels observed in the FDM group indicate the potential involvement of VIP in the pathogenesis and progression of myopia. The ability of atropine to reduce this phenomenon suggests that this may be one of the molecular mechanisms for atropine to control myopia.
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Miopía , Péptido Intestinal Vasoactivo , Animales , Cobayas , Atropina/farmacología , Miopía/genética , Retina/metabolismo , ARN Mensajero/genética , Modelos Animales de EnfermedadRESUMEN
Over the last two decades, the rapidly expanding field of tumor metabolism has enhanced our knowledge of the impact of nutrient availability on metabolic reprogramming in cancer. Apart from established roles in cancer cells themselves, various nutrients, metabolic enzymes, and stress responses are key to the activities of tumor microenvironmental immune, fibroblastic, endothelial, and other cell types that support malignant transformation. In this article, we review our current understanding of how nutrient availability affects metabolic pathways and responses in both cancer and "stromal" cells, by dissecting major examples and their regulation of cellular activity. Understanding the relationship of nutrient availability to cellular behaviors in the tumor ecosystem will broaden the horizon of exploiting novel therapeutic vulnerabilities in cancer.
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Neoplasias , Microambiente Tumoral , Humanos , Fibroblastos , NutrientesRESUMEN
BACKGROUND AND OBJECTIVE: The efficacy and safety of iGlarLixi, a fixed-ratio combination (FRC) of basal insulin glargine plus lixisenatide, have been demonstrated in type 2 diabetes mellitus (T2DM) patients. However, no relevant economic analysis of iGlarLixi has been done in China. Thus, the primary objective of this study is to evaluate the cost effectiveness of iGlarLixi versus IDegAsp in Chinese T2DM patients, and then back-calculate the appropriate drug price of iGlarLixi to support its pricing after listing in China. METHODS: The United Kingdom Prospective Diabetes Study Outcome Model 2 (UKPDS OM2) was applied to estimate lifetime health and economic outcomes from the Chinese health-care system perspective. As no head-to-head comparison data are currently available, the baseline cohort characteristics and the initial clinical data for iGlarLixi were derived from the randomized LixiLan-L-China trial. The relative treatment effects for IDegAsp were based on an indirect treatment comparison. Due to the unavailability of iGlarLixi pricing data, the annual medication cost of iGlarLixi was assumed to be equal to that of IDegAsp at the beginning of the study. Afterwards, a break-even analysis using comparator drug price and the willingness-to-pay (WTP) threshold was performed to back-calculate the appropriate drug price of iGlarLixi. One-way sensitivity analysis, scenario analysis and probabilistic sensitivity analysis (PSA) were conducted to assess the robustness of the model. RESULTS: Based on the initial assumption of equal annual medication cost of iGlarLixi and IDegAsp, iGlarLixi was cost effective compared to IDegAsp with an incremental cost-effectiveness ratio (ICER) far below the WTP threshold in Chinese T2DM patients. From the back calculation for the price of iGlarLixi, the annual medication cost of iGlarLixi was $656.96 and $1075.96 to obtain an ICER of iGlarLixi versus IDegAsp close to 1 × GDP and 3 × GDP, respectively. When the discount rate was changed from the base value to 8% (the most sensitive parameter to the model results in one-way sensitivity analysis), the ICER was nearly equal to 1 × GDP and 3 × GDP with the annual medication cost of iGlarLixi decreasing to $590.41 and $865.03, respectively. Thus, iGlarLixi was dominant over IDegAsp with an annual medication cost of $590.41 to $865.03. The findings were robust to one-way sensitivity analysis, PSA and scenario analysis. CONCLUSION: This long-term cost-effectiveness analysis in Chinese T2DM patients indicates that iGlarLixi, assuming equal price to IDegAsp, is cost-effective versus IDegAsp with an ICER far below the WTP threshold. With 1 × GDP and 3 × GDP threshold set we back-calculate the appropriate annual medication cost of iGlarLixi to be $590.41 to $865.03, respectively.
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Diabetes Mellitus Tipo 2 , Humanos , Glucemia , China , Análisis de Costo-Efectividad , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Combinación de Medicamentos , Hemoglobina Glucada , Hipoglucemiantes/uso terapéutico , Insulina Glargina/uso terapéutico , Péptidos , Estudios Prospectivos , Proyectos PilotoRESUMEN
Hyperuricemia (HUA) is associated with left ventricular remodeling (LVR) and thereby causes the initiation and development of a large number of cardiovascular diseases. LVR is typically accompanied by cardiomyocyte energy metabolic disorder. The energy supply of cardiomyocytes is provided by glucose and fatty acid (FA) metabolism. Currently, the effect of HUA on cardiomyocytic FA metabolism is unclear. In this study, we demonstrate that UA-induced cardiomyocyte injury is associated with cytoplasmic lipid deposition, which can be ameliorated by the FA metabolism-promoting drug L-carnitine (LC). UA suppresses carnitine palmitoyl transferase 1B (CPT1B), thereby inhibiting FA transport into the mitochondrial inner matrix for elimination. LC intervention can ameliorate HUA-associated left ventricular anterior wall thickening in mice. This study showed that FA transport dysfunction plays is a critical mechanism in both cardiomyocytic injury and HUA-associated LVR and promoting cytoplasmic FA transportation through pharmacological treatment by LC is a valid strategy to attenuate HUA-associated LVR.
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Despite the advantages of digital nucleic acid analysis (DNAA) in terms of sensitivity, precision, and resolution, current DNAA methods commonly suffer a limitation in multiplexing capacity. To address this issue, a droplet encoding-pairing enabled DNAA multiplexing strategy is developed, wherein unique tricolor combinations are deployed to index individual primer droplets. The template droplets and primer droplets are sequentially introduced into a microfluidic chip with a calabash-shaped microwell array and are pairwise trapped and merged in the microwells. Pre-merging and post-amplification image analysis with a machine learning algorithm is used to identify, enumerate, and address the droplets. By incorporating the amplification signals with droplet encoding information, simultaneous quantitative detection of multiple targets is achieved. This strategy allows for the establishment of flexible multiplexed DNAA by simply adjusting the primer droplet library. Its flexibility is demonstrated by establishing two multiplexed (8-plex) droplet digital loop-mediated isothermal amplification (mddLAMP) assays for individually detecting lower respiratory tract infection and urinary tract infection causative pathogens. Clinical sample analysis shows that the microbial detection outcomes of the mddLAMP assays are consistent with those of the conventional assay. This DNAA multiplexing strategy can achieve flexible high-order multiplexing on demand, making it a desirable tool for high-content pathogen detection.
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Microfluídica , Técnicas de Amplificación de Ácido Nucleico , Técnicas de Amplificación de Ácido Nucleico/métodosRESUMEN
Cellular cytoplasmic xanthine oxidase (XO)-mediated uric acid synthesis and extracellular excess uric acid exposure are both causes of cardiomyocytic injury under the condition of hyperuricemia (HUA). Potassium oxonate suppresses uric acid degradation to increase extracellular concentration, while hypoxanthine is the catalytic substrate of XO. We aimed to observe cardiac damage in a chronic HUA mouse model induced by potassium oxonate and hypoxanthine. The mouse model was established by the co-administration of potassium oxonate and hypoxanthine for eight weeks. Then, left ventricular parameters were examined by echocardiographic evaluation, and the heart tissues were harvested for further histopathological analysis. The results showed that plasma uric acid was persistently elevated in the model mice, which demonstrated the stable establishment of chronic HUA. The left ventricular anterior wall was significantly thickened in the model group compared with the blank control group. After the end of modeling, the left ventricular anterior wall thickness of the hyperuricemic mice increased compared with that of blank group. The histological analysis showed and myocardial structure disorganization in the model group compared with the blank control. The above cardiac impairment changes could be attenuated by allopurinol pretreatment. This study systematically assessed cardiac damage in a chronic HUA mouse model. In addition, it provides useful information for future HUA-associated heart injury mechanism investigation and therapeutic treatment evaluation.
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Hiperuricemia , Ratones , Animales , Hiperuricemia/inducido químicamente , Hiperuricemia/tratamiento farmacológico , Hiperuricemia/metabolismo , Ácido Úrico/metabolismo , Ventrículos Cardíacos/metabolismo , Hipoxantinas/uso terapéuticoRESUMEN
BACKGROUND: Recently, two naval pilots in a two-seat trainer jet were forced to eject urgently due to sudden mechanical failure during night-time training. They were both successfully rescued and sent to the hospital for emergency treatment. In this study, we investigate their ejection injuries and recovery process. CASE SUMMARY: We analyzed the clinical data of the traumatic condition and recovery process from ejection injuries of two pilots who ejected from a failed trainer jet and survived. After being successfully rescued and sent to the hospital, they were diagnosed with multiple ejection injuries, including eye trauma, limb bone and joint injury, rib and spine injury, and so on. Both cases underwent fluid replacement, acid suppression, nutritional support, hemostasis, bone metabolism improvement, phlegm elimination, psychological measurement, blood circulation promotion and detumescence, physical therapy, and external fixation with braces for 1 mo before being discharged from hospital. They then recuperated in a sanatorium for 2 mo, and the related laboratory tests and supplementary examinations show that they recovered from all the above injuries. After successfully passing the psychological test and physical examination, they returned to flight duty 3 mo after ejection. CONCLUSION: The causes and conditions of ejection injury in the pilots were very complex. Although they finally recovered quickly and were released, it also serves as a reminder that attention should be paid to pilots' ejection and parachute training in order to significantly reduce ejection injury and improve the ejection success rate. In addition, air defense support personnel should strengthen search and rescue and on-site emergency measures, and locate and rescue pilots in distress as early as possible to reduce subsequent injuries.
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BACKGROUND: Specific pulmonary infection could seriously threaten the health of pilots and their companions. The consequences are serious. We investigated the clinical diagnosis, treatment, and medical identification of specific pulmonary infections in naval pilots. CASE SUMMARY: We analyzed the medical waiver and clinical data of four pilots with specific pulmonary infections, who had accepted treatment at the Naval Medical Center of Chinese People's Liberation Army between January 2020 and November 2021, including three cases of tuberculosis and one of cryptococcal pneumonia. All cases underwent a series of comprehensive treatment courses. Three cases successfully obtained medical waiver for flight after being cured, while one was grounded after reaching the maximum flight life after being cured. CONCLUSION: Chest computed tomography scanning should be used instead of chest radiography in pilots' physical examination. Most pilots with specific pulmonary infection can be cured and return to flight.
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Aim: To evaluate the cost-effectiveness of first-line treatment for advanced renal cell carcinoma with nivolumab plus cabozantinib versus sunitinib from a US payer perspective. Methods: Economic outcomes were estimated with Markov and partitioned survival models. Efficacy, safety and other data were taken from the CheckMate 9ER trial. Costs and utilities were gathered from published sources. Sensitivity analyses addressed model uncertainties. Results: The incremental cost-effectiveness ratio of nivolumab plus cabozantinib versus sunitinib was US$555,663 and $531,748 per quality-adjusted life year in the Markov and partitioned survival models, respectively, exceeding the willingness-to-pay threshold (US$150,000 per quality-adjusted life-year). Sensitivity analyses showed robust outcomes. Conclusion: From a US payer perspective, first-line nivolumab plus cabozantinib for advanced renal cell carcinoma is not cost effective.
Renal cell carcinoma (RCC) is a common cancer in the USA. Up to 30% of patients with RCC are in an advanced stage of disease at diagnosis. RCC is difficult to cure, with an 11% chance of survival after 5 years for patients with advanced RCC. A recent clinical study showed that nivolumab plus cabozantinib (NC) had a greater benefit in patients with advanced RCC than sunitinib. The US FDA approved NC for advanced RCC, but NC is relatively expensive. This study explored the costeffectiveness of NC for advanced RCC versus sunitinib for a US payer using two costeffectiveness models developed based on the results of the aforementioned clinical study. The results showed that to gain an additional year in perfect health, NC costs an average of US$555,663 or $531,748 more versus sunitinib, which is more than a US payer is willing to pay for an additional year in perfect health ($150,000). Therefore, NC for advanced RCC is not cost-effective versus sunitinib for a US payer at current prices.
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Carcinoma de Células Renales , Neoplasias Renales , Anilidas , Análisis Costo-Beneficio , Humanos , Nivolumab/uso terapéutico , Piridinas , Sunitinib/uso terapéuticoRESUMEN
Accumulating evidence has shown that chronic injection of D-galactose (D-gal) can mimic natural ageing and induce liver and kidney injury. Previous studies showed that D-gal increased uric acid (UA) levels in mice. The increase in UA levels caused inflammation, accelerated oxidative stress, and aggravated liver and kidney injury. Oxidative stress and inflammation play vital roles in the ageing process. Therefore, reducing the levels of UA in ageing mice improved liver and kidney injury. Glucose transporter 9 (GLUT9) is responsible for the reabsorption of UA in the body, and its inhibition helps downregulate UA levels. The present study investigated the UA-lowering activity of the GLUT9 inhibitor resveratrol (RSV) using the patch clamping technique established in our laboratory in vitro. This research is the first study to demonstrate that RSV effectively inhibits UA uptake via GLUT9 (IC50 = 68.77 µM) in vitro. An in vivo study was also performed to investigate the possible protective effect of RSV on D-gal-induced liver and kidney injury. RSV significantly reduced serum UA levels via the downregulation of GLUT9 mRNA and protein expression and promoted the excretion of excess UA through urine. Biochemical analysis showed that RSV significantly downregulated abnormal increases in serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN) and creatinine (CRE) caused by long-term D-gal treatment, which effectively improved pathological damage, increased superoxide dismutase (SOD) activity and decreased the content of malondialdehyde (MDA) in the liver and kidneys. RSV also downregulated the expression of the inflammatory cytokines, interleukin IL-6, IL-1ß and tumor necrosis factor (TNF)-α in the liver and kidneys of ageing mice. Our findings provide new insights into the treatment strategies for ageing-induced liver and kidney injury and reveal a new mechanism of RSV-induced reduction in UA levels in ageing individuals.
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Envejecimiento/efectos de los fármacos , Galactosa/toxicidad , Regulación de la Expresión Génica/efectos de los fármacos , Proteínas Facilitadoras del Transporte de la Glucosa/metabolismo , Resveratrol/farmacología , Ácido Úrico/metabolismo , Animales , Supervivencia Celular/efectos de los fármacos , Enfermedad Hepática Inducida por Sustancias y Drogas/prevención & control , Células Epiteliales/efectos de los fármacos , Femenino , Proteínas Facilitadoras del Transporte de la Glucosa/antagonistas & inhibidores , Proteínas Facilitadoras del Transporte de la Glucosa/genética , Riñón/efectos de los fármacos , Túbulos Renales/citología , Hígado/efectos de los fármacos , Masculino , Ratones , Estructura Molecular , Transportadores de Anión Orgánico/antagonistas & inhibidores , Transportadores de Anión Orgánico/genética , Transportadores de Anión Orgánico/metabolismo , Resveratrol/químicaRESUMEN
BACKGROUND: Hyperuricemia (HUA) is characterized by abnormal serum uric acid (UA) levels and demonstrated to be involved in renal injury leading to hyperuricemic nephropathy (HN). Apigenin (API), a flavonoid naturally present in tea, berries, fruits, and vegetables, exhibits various biological functions, such as antioxidant and anti-inflammatory activity. PURPOSE: To investigate the effect of API treatment in HN and to reveal its underlying mechanisms. METHODS: The mice with HN were induced by potassium oxonate intraperitoneally and orally administered for two weeks. The effects of API on renal function, inflammation, fibrosis, and uric acid (UA) metabolism in mice with HN were evaluated. The effects of API on urate transporters were further examined in vitro. RESULTS: The mice with HN exhibited abnormal renal urate excretion and renal dysfunction accompanied by increased renal inflammation and fibrosis. In contrast, API reduced the levels of serum UA, serum creatinine (CRE), blood urea nitrogen (BUN) and renal inflammatory factors in mice with HN. Besides, API ameliorated the renal fibrosis via Wnt/ß-catenin pathway suppression. Furthermore, API potently promoted urinary UA excretion and inhibited renal urate transporter 1 (URAT1) and glucose transporter 9 (GLUT9) in mice with HN. In vitro, API competitively inhibited URAT1 and GLUT9 in a dose-dependent manner, with IC50 values of 0.64 ± 0.14 µM and 2.63 ± 0.69 µM, respectively. CONCLUSIONS: API could effectively attenuate HN through co-inhibiting UA reabsorption and Wnt/ß-catenin pathway, and thus it might be a potential therapy to HN.
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Apigenina/farmacología , Proteínas Facilitadoras del Transporte de la Glucosa/antagonistas & inhibidores , Hiperuricemia/tratamiento farmacológico , Enfermedades Renales/tratamiento farmacológico , Transportadores de Anión Orgánico/antagonistas & inhibidores , Animales , Apigenina/administración & dosificación , Creatinina/sangre , Relación Dosis-Respuesta a Droga , Fibrosis , Proteínas Facilitadoras del Transporte de la Glucosa/genética , Proteínas Facilitadoras del Transporte de la Glucosa/metabolismo , Células HEK293 , Humanos , Hiperuricemia/inducido químicamente , Hiperuricemia/fisiopatología , Enfermedades Renales/metabolismo , Enfermedades Renales/patología , Masculino , Ratones , Nefritis/tratamiento farmacológico , Nefritis/patología , Transportadores de Anión Orgánico/genética , Transportadores de Anión Orgánico/metabolismo , Ácido Oxónico/toxicidad , Ácido Úrico/sangre , Ácido Úrico/metabolismo , Vía de Señalización Wnt/efectos de los fármacos , beta Catenina/metabolismoRESUMEN
BACKGROUND: The health levels of young elderly individuals are generally low due to multiple factors. This study sought to analyze factors that affect the health of the young elderly to provide a reference for improving their level of health. METHODS: We used cluster sampling to survey 1,000 young elderly residents aged between 60 and 69 and living in Town P, District M, Shanghai. Health levels were assessed using the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36), Social Support Rate Score (SSRS), General Self-Efficacy Scale (GSES), and Health Promoting Lifestyle Profile II (HPLP II) instruments. Demographic characteristics were compared based on the SF-36 score and coupled with one-way analysis and stepwise regression analysis, to determine factors affecting health. RESULTS: The young elderly in this community have a high morbidity of chronic disease and score low in the SF-36, SSRS, GSES, and HPLP II. One-way analysis reveals that gender, education, marriage, current work, total social support score, total general self-efficacy score, and total health promoting score are factors affecting the scoring of the SF-36 and the results of stepwise regression analysis. Marriage, current working condition, age, total score of social support, total score of health promotion behavior, type of work, presence of chronic disease, and the number of children are positively correlated with the SF-36 score and can predict it. CONCLUSIONS: To improve the health of community living elderly young it is necessary to adopt appropriate health promotion measures which motivate their self-efficacy and health responsibility. Such measures include increasing interactions between the young elderly and medical resources and offering them public participation opportunities to ensure that they receive adequate social support.
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Estilo de Vida Saludable , Autoeficacia , Adulto , Anciano , Niño , China , Estudios Transversales , Humanos , Persona de Mediana Edad , Apoyo Social , Encuestas y CuestionariosRESUMEN
Although immunotherapy has revolutionized cancer care, patients with pancreatic ductal adenocarcinoma (PDA) rarely respond to these treatments, a failure that is attributed to poor infiltration and activation of T cells in the tumor microenvironment (TME). We performed an in vivo CRISPR screen and identified lysine demethylase 3A (KDM3A) as a potent epigenetic regulator of immunotherapy response in PDA. Mechanistically, KDM3A acts through Krueppel-like factor 5 (KLF5) and SMAD family member 4 (SMAD4) to regulate the expression of the epidermal growth factor receptor (EGFR). Ablation of KDM3A, KLF5, SMAD4, or EGFR in tumor cells altered the immune TME and sensitized tumors to combination immunotherapy, whereas treatment of established tumors with an EGFR inhibitor, erlotinib, prompted a dose-dependent increase in intratumoral T cells. This study defines an epigenetic-transcriptional mechanism by which tumor cells modulate their immune microenvironment and highlights the potential of EGFR inhibitors as immunotherapy sensitizers in PDA. SIGNIFICANCE: PDA remains refractory to immunotherapies. Here, we performed an in vivo CRISPR screen and identified an epigenetic-transcriptional network that regulates antitumor immunity by converging on EGFR. Pharmacologic inhibition of EGFR is sufficient to rewire the immune microenvironment. These results offer a readily accessible immunotherapy-sensitizing strategy for PDA.This article is highlighted in the In This Issue feature, p. 521.
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Epigénesis Genética , Regulación Neoplásica de la Expresión Génica , Neoplasias Pancreáticas/etiología , Neoplasias Pancreáticas/metabolismo , Microambiente Tumoral/genética , Animales , Biomarcadores de Tumor/genética , Sistemas CRISPR-Cas , Línea Celular Tumoral , Terapia Combinada , Receptores ErbB/genética , Receptores ErbB/metabolismo , Genómica/métodos , Humanos , Inmunidad/genética , Histona Demetilasas con Dominio de Jumonji/genética , Histona Demetilasas con Dominio de Jumonji/metabolismo , Linfocitos Infiltrantes de Tumor/inmunología , Linfocitos Infiltrantes de Tumor/metabolismo , Linfocitos Infiltrantes de Tumor/patología , Ratones , Mutación , Neoplasias Pancreáticas/mortalidad , Neoplasias Pancreáticas/patología , Pronóstico , Linfocitos T/inmunología , Linfocitos T/metabolismo , Linfocitos T/patología , Transcriptoma , Resultado del TratamientoRESUMEN
Posterior fossa A (PFA) ependymomas are lethal malignancies of the hindbrain in infants and toddlers. Lacking highly recurrent somatic mutations, PFA ependymomas are proposed to be epigenetically driven tumors for which model systems are lacking. Here we demonstrate that PFA ependymomas are maintained under hypoxia, associated with restricted availability of specific metabolites to diminish histone methylation, and increase histone demethylation and acetylation at histone 3 lysine 27 (H3K27). PFA ependymomas initiate from a cell lineage in the first trimester of human development that resides in restricted oxygen. Unlike other ependymomas, transient exposure of PFA cells to ambient oxygen induces irreversible cellular toxicity. PFA tumors exhibit a low basal level of H3K27me3, and, paradoxically, inhibition of H3K27 methylation specifically disrupts PFA tumor growth. Targeting metabolism and/or the epigenome presents a unique opportunity for rational therapy for infants with PFA ependymoma.
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Ependimoma/genética , Ependimoma/metabolismo , Epigenoma/genética , Neoplasias Infratentoriales/genética , Neoplasias Infratentoriales/metabolismo , Animales , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Línea Celular , Proliferación Celular/genética , Metilación de ADN/genética , Epigenómica/métodos , Histonas/genética , Histonas/metabolismo , Humanos , Lactante , Lisina/genética , Lisina/metabolismo , Masculino , Ratones Endogámicos C57BL , Mutación/genéticaRESUMEN
Epithelial plasticity, reversible modulation of a cell's epithelial and mesenchymal features, is associated with tumor metastasis and chemoresistance, leading causes of cancer mortality. Although different master transcription factors and epigenetic modifiers have been implicated in this process in various contexts, the extent to which a unifying, generalized mechanism of transcriptional regulation underlies epithelial plasticity remains largely unknown. Here, through targeted CRISPR/Cas9 screening, we discovered two histone-modifying enzymes involved in the writing and erasing of H3K36me2 that act reciprocally to regulate epithelial-to-mesenchymal identity, tumor differentiation, and metastasis. Using a lysine-to-methionine histone mutant to directly inhibit H3K36me2, we found that global modulation of the mark is a conserved mechanism underlying the mesenchymal state in various contexts. Mechanistically, regulation of H3K36me2 reprograms enhancers associated with master regulators of epithelial-to-mesenchymal state. Our results thus outline a unifying epigenome-scale mechanism by which a specific histone modification regulates cellular plasticity and metastasis in cancer. SIGNIFICANCE: Although epithelial plasticity contributes to cancer metastasis and chemoresistance, no strategies exist for pharmacologically inhibiting the process. Here, we show that global regulation of a specific histone mark, H3K36me2, is a universal epigenome-wide mechanism that underlies epithelial-to-mesenchymal transition and mesenchymal-to-epithelial transition in carcinoma cells. These results offer a new strategy for targeting epithelial plasticity in cancer.This article is highlighted in the In This Issue feature, p. 747.
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Regulación Neoplásica de la Expresión Génica , N-Metiltransferasa de Histona-Lisina/genética , Histonas/genética , Neoplasias/genética , Transición Epitelial-Mesenquimal , HumanosRESUMEN
Intermittent fasting (IF) is an effective dietary intervention to counteract obesity-associated metabolic abnormalities. Previously, we and others have highlighted white adipose tissue (WAT) browning as the main underlying mechanism of IF-mediated metabolic benefits. However, whether IF retains its efficacy in different models, such as genetically obese/diabetic animals, is unknown. Here, leptin-deficient ob/ob mice were subjected to 16 weeks of isocaloric IF, and comprehensive metabolic phenotyping was conducted to assess the metabolic effects of IF. Unlike our previous study, isocaloric IF-subjected ob/ob animals failed to exhibit reduced body weight gain, lower fat mass, or decreased liver lipid accumulation. Moreover, isocaloric IF did not result in increased thermogenesis nor induce WAT browning in ob/ob mice. These findings indicate that isocaloric IF may not be an effective approach for regulating body weight in ob/ob animals, posing the possible limitations of IF to treat obesity. However, despite the lack of improvement in insulin sensitivity, isocaloric IF-subjected ob/ob animals displayed improved glucose tolerance as well as higher postprandial insulin level, with elevated incretin expression, suggesting that isocaloric IF is effective in improving nutrient-stimulated insulin secretion. Together, this study uncovers the insulinotropic effect of isocaloric IF, independent of adipose thermogenesis, which is potentially complementary for the treatment of type 2 diabetes.