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Over the past few decades, basic studies aimed at curing patients with cancer have been constantly evolving. A myriad of mechanistic studies on physiological changes and related factors in tumor growth and metastasis have been reported. Recently, several studies have been considerate to how tumors adapt to unfavorable environments, such as glucose deprivation, oxidative stress, hypoxic conditions, and immune responses. Tumors attempt to adapt to unfavorable environments with genetic or non-genetic changes, the alteration of metabolic signals, or the reconfiguration of their environment through migration to other organs. One of the distinct features in solid tumors is heterogeneity because their environments vary due to the characteristics of colony growth. For this reason, researchers are paying attention to the communication between growing tumors and neighboring environments, including stromal cells, immune cells, fibroblasts, and secreted molecules, such as proteins and RNAs. During cancer survival and progression, tumor cells undergo phenotype and molecular changes collectively referred to as cellular plasticity, which result from microenvironment signals, genetics and epigenetic alterations thereby contributing to tumor heterogeneity and therapy response. In this review, we herein discuss the adaptation process of tumors to adverse environments via communication with neighboring cells for overcoming unfavorable growth conditions. Understanding the physiology of these tumors and their communication with the tumor environment can help to develop promising tumor treatment strategies.
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Neoplasias , Microambiente Tumoral , Fibroblastos/metabolismo , Humanos , Inmunidad , Neoplasias/terapia , Células del Estroma/metabolismoRESUMEN
Accumulating evidence suggests that developmentally regulated GTP-binding protein 2 (DRG2), an evolutionarily conserved GTP-binding protein, plays an important role in regulating cell growth, inflammation, and mitochondria dynamics. However, the effect of DRG2 in aging remains unclear. In this study, we found that endogenous DRG2 protein expression is upregulated in oxidative stress-induced premature senescence models and tissues of aged mice. Ectopic expression of DRG2 significantly promoted senescence-associated ß-galactosidase (SA-ß-gal) activity and inhibited cell growth, concomitant with increase in levels of acetyl (ac)-p53 (Lys382), ac-nuclear factor-kB (NF-κB) p65 (Lys310), p21 Waf1/Cip1 , and p16 Ink4a and a decrease in cyclin D1. In this process, reactive oxygen species (ROS) and phosphorylation of H2A histone family member X (H2A.X), forming γ-H2A.X, were enhanced. Mechanistically, ectopic expression of DRG2 downregulated Sirtuin-1 (SIRT1), resulting in augmented acetylation of p53 and NF-κB p65. Additionally, DRG2 knockdown significantly abolished oxidative stress-induced premature senescence. Our results provide a possible molecular mechanism for investigation of cellular senescence and aging regulated by DRG2.
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Senescencia Celular , Diploidia , Fibroblastos/fisiología , Proteínas de Unión al GTP/metabolismo , Sirtuina 1/antagonistas & inhibidores , Animales , Fibroblastos/citología , Proteínas de Unión al GTP/genética , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Sirtuina 1/genética , Sirtuina 1/metabolismoRESUMEN
Luteolin, a sort of flavonoid, has been reported to be involved in neuroprotective function via suppression of neuroinflammation. In this study, we investigated the protective effect of luteolin against oxidative stress-induced cellular senescence and its molecular mechanism using hydrogen peroxide (H2O2)-induced cellular senescence model in House Ear Institute-Organ of Corti 1 cells (HEI-OC1). Our results showed that luteolin attenuated senescent phenotypes including alterations of morphology, cell proliferation, senescence-associated ß-galactosidase expression, DNA damage, as well as related molecules expression such as p53 and p21 in the oxidant challenged model. Interestingly, we found that luteolin induces expression of sirtuin 1 in dose- and time-dependent manners and it has protective role against H2O2-induced cellular senescence by upregulation of sirtuin 1 (SIRT1). In contrast, the inhibitory effect of luteolin on cellular senescence under oxidative stress was abolished by silencing of SIRT1. This study indicates that luteolin effectively protects against oxidative stress-induced cellular senescence through p53 and SIRT1. These results suggest that luteolin possesses therapeutic potentials against age-related hearing loss that are induced by oxidative stress.
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Oxidative stress-induced cellular senescence is now regarded as an important driving mechanism in chronic lung diseases-particularly chronic obstructive pulmonary disease (COPD). 4[Formula: see text],5,7-trihydroxyflavone (Apigenin) is a natural flavonoid product abundantly present in fruits, vegetables, and Chinese medicinal herbs. It has been known that apigenin has anti-oxidant, anti-inflammatory and liver-protecting effects. The efficacy of apigenin for lung aging, however, has not been reported. In this study, we selected the hydrogen peroxide (H2O[Formula: see text]- or doxorubicin (DOXO)-induced senescence model in WI-38 human embryonic lung fibroblast cells to determine the potential anti-aging effects of apigenin in vitro and associated molecular mechanisms. We found that apigenin reduced senescence-associated [Formula: see text]-galactosidase (SA-[Formula: see text]-gal) activity and promoted cell growth, concomitant with a decrease in levels of Acetyl (ac)-p53, p21[Formula: see text], and p16[Formula: see text] and an increase in phospho (p)-Rb. Apigenin also increased the activation ratio of silent information regulator 1 (SIRT1), nicotinamide adenine dinucleotide (NAD[Formula: see text], and NAD[Formula: see text]/NADH and inhibited cluster of differentiation 38 (CD38) activity in a concentration-dependent manner. SIRT1 inhibition by SIRT1 siRNA abolished the anti-aging effect of apigenin. In addition, CD38 inhibition by CD38 siRNA or apigenin increased the SIRT1 level and reduced H2O2-induced senescence. Our findings suggest that apigenin is a promising phytochemical for reducing the impact of senescent cells in age-related lung diseases such as COPD.
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Apigenina/farmacología , Senescencia Celular/efectos de los fármacos , Fibroblastos/efectos de los fármacos , NAD/metabolismo , Estrés Oxidativo/efectos de los fármacos , Sirtuina 1/metabolismo , Apigenina/química , Línea Celular , Humanos , Peróxido de Hidrógeno , Pulmón/citología , Estructura MolecularRESUMEN
BACKGROUND: The number of deaths from COVID-19 continues to surge worldwide. In particular, if a patient's condition is sufficiently severe to require invasive ventilation, it is more likely to lead to death than to recovery. OBJECTIVE: The goal of our study was to analyze the factors related to COVID-19 severity in patients and to develop an artificial intelligence (AI) model to predict the severity of COVID-19 at an early stage. METHODS: We developed an AI model that predicts severity based on data from 5601 COVID-19 patients from all national and regional hospitals across South Korea as of April 2020. The clinical severity of COVID-19 was divided into two categories: low and high severity. The condition of patients in the low-severity group corresponded to no limit of activity, oxygen support with nasal prong or facial mask, and noninvasive ventilation. The condition of patients in the high-severity group corresponded to invasive ventilation, multi-organ failure with extracorporeal membrane oxygenation required, and death. For the AI model input, we used 37 variables from the medical records, including basic patient information, a physical index, initial examination findings, clinical findings, comorbid diseases, and general blood test results at an early stage. Feature importance analysis was performed with AdaBoost, random forest, and eXtreme Gradient Boosting (XGBoost); the AI model for predicting COVID-19 severity among patients was developed with a 5-layer deep neural network (DNN) with the 20 most important features, which were selected based on ranked feature importance analysis of 37 features from the comprehensive data set. The selection procedure was performed using sensitivity, specificity, accuracy, balanced accuracy, and area under the curve (AUC). RESULTS: We found that age was the most important factor for predicting disease severity, followed by lymphocyte level, platelet count, and shortness of breath or dyspnea. Our proposed 5-layer DNN with the 20 most important features provided high sensitivity (90.2%), specificity (90.4%), accuracy (90.4%), balanced accuracy (90.3%), and AUC (0.96). CONCLUSIONS: Our proposed AI model with the selected features was able to predict the severity of COVID-19 accurately. We also made a web application so that anyone can access the model. We believe that sharing the AI model with the public will be helpful in validating and improving its performance.
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Inteligencia Artificial , COVID-19/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , COVID-19/mortalidad , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Modelos Estadísticos , Mortalidad , República de Corea/epidemiología , Proyectos de Investigación , Estudios Retrospectivos , Factores de Riesgo , SARS-CoV-2 , Adulto JovenRESUMEN
BACKGROUND: COVID-19, which is accompanied by acute respiratory distress, multiple organ failure, and death, has spread worldwide much faster than previously thought. However, at present, it has limited treatments. OBJECTIVE: To overcome this issue, we developed an artificial intelligence (AI) model of COVID-19, named EDRnet (ensemble learning model based on deep neural network and random forest models), to predict in-hospital mortality using a routine blood sample at the time of hospital admission. METHODS: We selected 28 blood biomarkers and used the age and gender information of patients as model inputs. To improve the mortality prediction, we adopted an ensemble approach combining deep neural network and random forest models. We trained our model with a database of blood samples from 361 COVID-19 patients in Wuhan, China, and applied it to 106 COVID-19 patients in three Korean medical institutions. RESULTS: In the testing data sets, EDRnet provided high sensitivity (100%), specificity (91%), and accuracy (92%). To extend the number of patient data points, we developed a web application (BeatCOVID19) where anyone can access the model to predict mortality and can register his or her own blood laboratory results. CONCLUSIONS: Our new AI model, EDRnet, accurately predicts the mortality rate for COVID-19. It is publicly available and aims to help health care providers fight COVID-19 and improve patients' outcomes.
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COVID-19/mortalidad , Adulto , Anciano , Inteligencia Artificial , China , Femenino , Hospitalización , Humanos , Masculino , Persona de Mediana Edad , Redes Neurales de la Computación , República de Corea , SARS-CoV-2RESUMEN
Lysyl oxidase-variant 2 (LOX-v2) is a novel variant of LOX that functions as an amine oxidase for the formation of collagen and elastin fibrils in the extracellular matrix (ECM). LOX-v2 lacks the N-terminal prepropeptide region of LOX but contains the C-terminal domains required for amine oxidase activity. To study the cellular localization of LOX-v2, we generated a recombinant construct of LOX-v2 with an epitope tag at the C-terminus and then transfected the recombinant construct into HEK293 cells. Upon ectopic expression, LOX-v2 showed much higher expression in the nucleus than in the cytoplasm. In coimmunofluorescence staining with subnuclear structures, LOX-v2 colocalized with the promyelocytic leukemia-nuclear bodies (PML-NBs). Further, the ectopic expression of LOX-v2 increased global SUMOylation in the nucleus. PML-NBs have been implicated in various cellular activities, including transcriptional regulation, DNA repair, cell cycle control, anti-viral response, and apoptosis. Our findings strongly indicate that LOX-v2 may be subject to different cellular processing from what LOX undergoes, playing a distinct functional role in the PML-NBs, beyond the cross-linking of the structural proteins.
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Núcleo Celular/metabolismo , Regulación Enzimológica de la Expresión Génica , Mutación , Proteína de la Leucemia Promielocítica/metabolismo , Proteína-Lisina 6-Oxidasa/genética , Proteína-Lisina 6-Oxidasa/metabolismo , Sumoilación , Núcleo Celular/genética , Células HEK293 , Humanos , Cuerpos de Inclusión Intranucleares , Proteína de la Leucemia Promielocítica/genéticaRESUMEN
Acute pancreatitis (AP) refers to inflammation in the pancreas, which may lead to death in severe cases. Coenzyme Q10 (Q10), generally known to generate energy, plays an important role as an anti-oxidant and anti-inflammatory effector. Here, we showed the effect of Q10 on inflammatory response in murine AP model. For this study, we induced AP by injection of cerulein intraperitoneally or pancreatic duct ligation (PDL) in mice. The level of cytokines and digestive enzymes were measured in pancreas, and blood. All pancreatic tissues were excised for investigation such as histological changes, infiltration of immune cells. Administration of Q10 attenuated the severity of AP and its associated pulmonary complication as shown by reduction of acinar cell death, parenchymal edema, inflammatory cell infiltration and alveolar thickening in both cerulein-induced AP and PDL-induced AP. Moreover, reduction of the cytokines such as interleukin (IL)-1ß, IL-6 and tumor necrosis factor (TNF)-α were observed in pancreas and pancreatic acinar cells by Q10. Furthermore, Q10 reduced the infiltration of immune cells such as monocytes and neutrophils and augmentation of chemokines such as CC chemokine-2 (CCL2) and C-X-C chemokine-2 (CXCL2) in pancreas of AP mice. In addition, Q10 deactivates the phosphorylation of extracellular signal-regulated kinase (ERK) and c-jun NH2-terminal kinase (JNK) in pancreas. In conclusion, these observations suggest that Q10 could attenuate the pancreatic damage and its associated pulmonary complications via inhibition of inflammatory cytokines and inflammatory cell infiltration and that the deactivation of ERK and JNK by Q10 might contribute to the attenuation of AP.
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Antiinflamatorios/uso terapéutico , Pancreatitis/tratamiento farmacológico , Ubiquinona/análogos & derivados , Animales , Antiinflamatorios/farmacología , Ceruletida , Citocinas/genética , Citocinas/inmunología , Femenino , Pulmón/efectos de los fármacos , Pulmón/patología , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Ratones Endogámicos C57BL , Monocitos/efectos de los fármacos , Monocitos/inmunología , Infiltración Neutrófila/efectos de los fármacos , Neutrófilos/efectos de los fármacos , Neutrófilos/inmunología , Páncreas/efectos de los fármacos , Páncreas/inmunología , Páncreas/patología , Pancreatitis/inducido químicamente , Pancreatitis/inmunología , Pancreatitis/patología , Ubiquinona/farmacología , Ubiquinona/uso terapéuticoRESUMEN
Mitochondria are signaling hubs in eukaryotic cells. Here, we showed that the mitochondrial FUN14 domain-containing protein-1 (FUNDC1), an effector of Parkin-independent mitophagy, also participates in cellular plasticity by sustaining oxidative bioenergetics, buffering ROS production, and supporting cell proliferation. Targeting this pathway in cancer cells suppressed tumor growth but rendered transformed cells more motile and invasive in a manner dependent on ROS-mediated mitochondrial dynamics and mitochondrial repositioning to the cortical cytoskeleton. Global metabolomics and proteomics profiling identified a FUNDC1 interactome at the mitochondrial inner membrane, comprising the AAA+ protease, LonP1, and subunits of oxidative phosphorylation, complex V (ATP synthase). Independently of its previously identified role in mitophagy, FUNDC1 enabled LonP1 proteostasis, which in turn preserved complex V function and decreased ROS generation. Therefore, mitochondrial reprogramming by a FUNDC1-LonP1 axis controls tumor cell plasticity by switching between proliferative and invasive states in cancer.
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Proteínas de la Membrana/metabolismo , Mitocondrias/metabolismo , Proteínas Mitocondriales/metabolismo , Mitofagia , Proteínas de Neoplasias/metabolismo , Neoplasias/metabolismo , Células A549 , Animales , Humanos , Células MCF-7 , Proteínas de la Membrana/genética , Ratones , Proteínas Mitocondriales/genética , Células 3T3 NIH , Proteínas de Neoplasias/genética , Neoplasias/genética , Células PC-3RESUMEN
Latifolin, a natural flavonoid found in Dalbergia odorifera T. Chen, has been reported to exhibit anti-inflammatory and anticarcinogenic activities in vitro. However, the anti-aging effects of latifolin are unknown. In this study, we selected a model in vitro system, hydrogen peroxide (H2O2)-induced senescence in human dermal fibroblasts (HDFs), to examine the protective effects of latifolin against senescence and the detailed molecular mechanisms involved. Latifolin reversed the senescence-like phenotypes of the oxidant-challenged model, including senescence-associated ß-galactosidase (SA-ß-gal) staining, cell proliferation, and the expression of senescence-related proteins, such as caveolin-1, ac-p53, p21Cip1/WAF1, p16Ink4α, pRb, and cyclinD1. We also found that latifolin induced the expression of silent information regulator 1 (SIRT1) in a concentration- and time-dependent manner, and the anti-senescence effect of latifolin was abrogated by SIRT1 inhibition. Latifolin also suppressed the activation of Akt and S6K1 and attenuated the increase in SA-ß-gal activity after H2O2 exposure. Our results indicate that latifolin exerts protective effects against senescence in HDFs and that induction of SIRT1 and inhibition of the mammalian target of rapamycin (mTOR) pathway are key mediators of its anti-aging effects.
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Senescencia Celular/efectos de los fármacos , Fibroblastos/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Fenoles/farmacología , Sirtuina 1/biosíntesis , Regulación hacia Arriba/efectos de los fármacos , Células Cultivadas , Senescencia Celular/fisiología , Relación Dosis-Respuesta a Droga , Fibroblastos/metabolismo , Humanos , Peróxido de Hidrógeno/toxicidad , Estrés Oxidativo/fisiología , Piel/citología , Piel/efectos de los fármacos , Piel/metabolismo , Regulación hacia Arriba/fisiologíaRESUMEN
The regulators of mitochondrial cell death in cancer have remained elusive, hampering the development of new therapies. Here, we showed that protein isoforms of mitochondrial fission factor (MFF1 and MFF2), a molecule that controls mitochondrial size and shape, that is, mitochondrial dynamics, were overexpressed in patients with non-small cell lung cancer and formed homo- and heterodimeric complexes with the voltage-dependent anion channel-1 (VDAC1), a key regulator of mitochondrial outer membrane permeability. MFF inserted into the interior hole of the VDAC1 ring using Arg225, Arg236, and Gln241 as key contact sites. A cell-permeable MFF Ser223-Leu243 d-enantiomeric peptidomimetic disrupted the MFF-VDAC1 complex, acutely depolarized mitochondria, and triggered cell death in heterogeneous tumor types, including drug-resistant melanoma, but had no effect on normal cells. In preclinical models, treatment with the MFF peptidomimetic was well-tolerated and demonstrated anticancer activity in patient-derived xenografts, primary breast and lung adenocarcinoma 3D organoids, and glioblastoma neurospheres. These data identify the MFF-VDAC1 complex as a novel regulator of mitochondrial cell death and an actionable therapeutic target in cancer. SIGNIFICANCE: These findings describe mitochondrial fission regulation using a peptidomimetic agent that disturbs the MFF-VDAC complex and displays anticancer activity in multiple tumor models.See related commentary by Rao, p. 6074.
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Carcinoma de Pulmón de Células no Pequeñas/patología , Neoplasias Pulmonares/patología , Proteínas de la Membrana/metabolismo , Mitocondrias/patología , Dinámicas Mitocondriales/efectos de los fármacos , Proteínas Mitocondriales/metabolismo , Animales , Apoptosis/efectos de los fármacos , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Línea Celular Tumoral , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Masculino , Proteínas de la Membrana/antagonistas & inhibidores , Ratones , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Membranas Mitocondriales/efectos de los fármacos , Membranas Mitocondriales/patología , Proteínas Mitocondriales/antagonistas & inhibidores , Permeabilidad/efectos de los fármacos , Multimerización de Proteína/efectos de los fármacos , Canal Aniónico 1 Dependiente del Voltaje/antagonistas & inhibidores , Canal Aniónico 1 Dependiente del Voltaje/metabolismo , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
The role of mitochondria in cancer continues to be debated and paradoxically implicated in opposing functions in tumor growth and tumor suppression. To understand this dichotomy, we explored the function of mitochondrial isocitrate dehydrogenase (IDH)2, a tricarboxylic acid cycle enzyme mutated in subsets of acute leukemias and gliomas, in cancer. Silencing of IDH2 in prostate cancer cells impaired oxidative bioenergetics, elevated reactive oxygen species (ROS) production, and promoted exaggerated mitochondrial dynamics. This was associated with increased subcellular mitochondrial trafficking, turnover of membrane focal adhesion complexes, and enhanced tumor cell migration and invasion, without changes in cell cycle progression. Mechanistically, loss of IDH2 caused ROS-dependent stabilization of hypoxia-inducible factor-1α in normoxia, which was required for increased mitochondrial trafficking and tumor cell movements. Therefore, IDH2 is a dual regulator of cancer bioenergetics and tumor cell motility. This pathway may reprogram mitochondrial dynamics to differentially adjust energy production or promote tumor cell invasion in response to microenvironment conditions.-Wang, Y., Agarwal, E., Bertolini, I., Ghosh, J. C., Seo, J. H., Altieri, D. C. IDH2 reprograms mitochondrial dynamics in cancer through a HIF-1α-regulated pseudohypoxic state.
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Metabolismo Energético , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Hipoxia/fisiopatología , Isocitrato Deshidrogenasa/metabolismo , Mitocondrias/metabolismo , Dinámicas Mitocondriales , Neoplasias de la Próstata/patología , Animales , Apoptosis , Movimiento Celular , Proliferación Celular , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Isocitrato Deshidrogenasa/genética , Masculino , Ratones , Mitocondrias/patología , Oxidación-Reducción , Neoplasias de la Próstata/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
BACKGROUND: Mitochondrial functions are exploited in cancer and provide a validated therapeutic target. However, how this process is regulated has remained mostly elusive and the identification of new pathways that control mitochondrial integrity in cancer is an urgent priority. METHODS: We studied clinically-annotated patient series of primary and metastatic prostate cancer, representative cases of multiple myeloma (MM) and publicly available genetic databases. Gene regulation studies involved chromatin immunoprecipitation, PCR amplification and Western blotting of conditional Myc-expressing cell lines. Transient or stable gene silencing was used to quantify mitochondrial functions in bioenergetics, outer membrane permeability, Ca2+ homeostasis, redox balance and cell death. Tumorigenicity was assessed by cell proliferation, colony formation and xenograft tumour growth. FINDINGS: We identified Mitochondrial Fission Factor (MFF) as a novel transcriptional target of oncogenic Myc overexpressed in primary and metastatic cancer, compared to normal tissues. Biochemically, MFF isoforms, MFF1 and MFF2 associate with the Voltage-Dependent Anion Channel-1 (VDAC1) at the mitochondrial outer membrane, in vivo. Disruption of this complex by MFF silencing induces general collapse of mitochondrial functions with increased outer membrane permeability, loss of inner membrane potential, Ca2+ unbalance, bioenergetics defects and activation of cell death pathways. In turn, this inhibits tumour cell proliferation, suppresses colony formation and reduces xenograft tumour growth in mice. INTERPRETATION: An MFF-VDAC1 complex is a novel regulator of mitochondrial integrity and actionable therapeutic target in cancer.
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Mitocondrias/genética , Mitocondrias/metabolismo , Dinámicas Mitocondriales/genética , Neoplasias/genética , Neoplasias/metabolismo , Proteínas Proto-Oncogénicas c-myc/genética , Línea Celular Tumoral , Permeabilidad de la Membrana Celular , Proliferación Celular , Humanos , Potencial de la Membrana Mitocondrial/genética , Proteínas Mitocondriales/genética , PermeabilidadRESUMEN
Tumor mitochondria have heightened protein folding quality control, but the regulators of this process and how they impact cancer traits are not completely understood. Here we show that the ATP-directed mitochondrial protease, LonP1 is upregulated by stress conditions, including hypoxia, in tumor, but not normal cells. In mitochondria, LonP1 is phosphorylated by Akt on Ser173 and Ser181, enhancing its protease activity. Interference with this pathway induces accumulation of misfolded subunits of electron transport chain complex II and complex V, resulting in impaired oxidative bioenergetics and heightened ROS production. Functionally, this suppresses mitochondrial trafficking to the cortical cytoskeleton, shuts off tumor cell migration and invasion, and inhibits primary and metastatic tumor growth, in vivo. These data identify LonP1 as a key effector of mitochondrial reprogramming in cancer and potential therapeutic target.
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Proteasas ATP-Dependientes/metabolismo , Mitocondrias/metabolismo , Proteínas Mitocondriales/metabolismo , Neoplasias/metabolismo , Fosforilación/fisiología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Animales , Línea Celular Tumoral , Movimiento Celular/fisiología , Proliferación Celular/fisiología , Complejo II de Transporte de Electrones/metabolismo , Humanos , Ratones , Ratones Desnudos , Oxidación-Reducción , Estrés Oxidativo/fisiología , Células PC-3 , Especies Reactivas de Oxígeno/metabolismoRESUMEN
The role of mitochondria in cancer continues to be debated, and whether exploitation of mitochondrial functions is a general hallmark of malignancy or a tumor- or context-specific response is still unknown. Using a variety of cancer cell lines and several technical approaches, including siRNA-mediated gene silencing, ChIP assays, global metabolomics and focused metabolite analyses, bioenergetics, and cell viability assays, we show that two oncogenic Myc proteins, c-Myc and N-Myc, transcriptionally control the expression of the mitochondrial chaperone TNFR-associated protein-1 (TRAP1) in cancer. In turn, this Myc-mediated regulation preserved the folding and function of mitochondrial oxidative phosphorylation (OXPHOS) complex II and IV subunits, dampened reactive oxygen species production, and enabled oxidative bioenergetics in tumor cells. Of note, we found that genetic or pharmacological targeting of this pathway shuts off tumor cell motility and invasion, kills Myc-expressing cells in a TRAP1-dependent manner, and suppresses primary and metastatic tumor growth in vivo We conclude that exploitation of mitochondrial functions is a general trait of tumorigenesis and that this reliance of cancer cells on mitochondrial OXPHOS pathways could offer an actionable therapeutic target in the clinic.
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Proteínas HSP90 de Choque Térmico/metabolismo , Mitocondrias/metabolismo , Proteínas Proto-Oncogénicas c-myc/metabolismo , Animales , Línea Celular Tumoral , Movimiento Celular , Supervivencia Celular/efectos de los fármacos , Guanidinas/farmacología , Guanidinas/uso terapéutico , Proteínas HSP90 de Choque Térmico/genética , Humanos , Lactamas Macrocíclicas/farmacología , Lactamas Macrocíclicas/uso terapéutico , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Hepáticas/secundario , Masculino , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Ratones , Ratones Desnudos , Fosforilación Oxidativa , Regiones Promotoras Genéticas , Neoplasias de la Próstata/tratamiento farmacológico , Neoplasias de la Próstata/patología , Proteínas Proto-Oncogénicas c-myc/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-myc/genética , Interferencia de ARN , ARN Interferente Pequeño/metabolismo , Transcripción GenéticaRESUMEN
Syntaphilin (SNPH) inhibits the movement of mitochondria in tumor cells, preventing their accumulation at the cortical cytoskeleton and limiting the bioenergetics of cell motility and invasion. Although this may suppress metastasis, the regulation of the SNPH pathway is not well understood. Using a global proteomics screen, we show that SNPH associates with multiple regulators of ubiquitin-dependent responses and is ubiquitinated by the E3 ligase CHIP (or STUB1) on Lys111 and Lys153 in the microtubule-binding domain. SNPH ubiquitination did not result in protein degradation, but instead anchored SNPH on tubulin to inhibit mitochondrial motility and cycles of organelle fusion and fission, that is dynamics. Expression of ubiquitination-defective SNPH mutant Lys111âArg or Lys153âArg increased the speed and distance traveled by mitochondria, repositioned mitochondria to the cortical cytoskeleton, and supported heightened tumor chemotaxis, invasion, and metastasis in vivo Interference with SNPH ubiquitination activated mitochondrial dynamics, resulting in increased recruitment of the fission regulator dynamin-related protein-1 (Drp1) to mitochondria and Drp1-dependent tumor cell motility. These data uncover nondegradative ubiquitination of SNPH as a key regulator of mitochondrial trafficking and tumor cell motility and invasion. In this way, SNPH may function as a unique, ubiquitination-regulated suppressor of metastasis.Significance: These findings reveal a new mechanism of metastasis suppression by establishing the role of SNPH ubiquitination in inhibiting mitochondrial dynamics, chemotaxis, and metastasis. Cancer Res; 78(15); 4215-28. ©2018 AACR.
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Movimiento Celular/fisiología , Mitocondrias/metabolismo , Neoplasias/metabolismo , Neoplasias/patología , Proteínas del Tejido Nervioso/metabolismo , Ubiquitinación/fisiología , Proteínas de Transporte Vesicular/metabolismo , Animales , Línea Celular , Línea Celular Tumoral , Citoesqueleto/metabolismo , Citoesqueleto/fisiología , Dinaminas/metabolismo , Humanos , Masculino , Proteínas de la Membrana , Ratones , Ratones Endogámicos C57BL , Mitocondrias/patología , Dinámicas Mitocondriales/fisiología , Células 3T3 NIH , Células PC-3 , Ubiquitina-Proteína Ligasas/metabolismoRESUMEN
Tumors adapt to an unfavorable microenvironment by controlling the balance between cell proliferation and cell motility, but the regulators of this process are largely unknown. Here, we show that an alternatively spliced isoform of syntaphilin (SNPH), a cytoskeletal regulator of mitochondrial movements in neurons, is directed to mitochondria of tumor cells. Mitochondrial SNPH buffers oxidative stress and maintains complex II-dependent bioenergetics, sustaining local tumor growth while restricting mitochondrial redistribution to the cortical cytoskeleton and tumor cell motility. Conversely, introduction of stress stimuli to the microenvironment, including hypoxia, acutely lowered SNPH levels, resulting in bioenergetics defects and increased superoxide production. In turn, this suppressed tumor cell proliferation but increased tumor cell invasion via greater mitochondrial trafficking to the cortical cytoskeleton. Loss of SNPH or expression of an SNPH mutant lacking the mitochondrial localization sequence resulted in increased metastatic dissemination in xenograft or syngeneic tumor models in vivo. Accordingly, tumor cells that acquired the ability to metastasize in vivo constitutively downregulated SNPH and exhibited higher oxidative stress, reduced cell proliferation, and increased cell motility. Therefore, SNPH is a stress-regulated mitochondrial switch of the cell proliferation-motility balance in cancer, and its pathway may represent a therapeutic target.
Asunto(s)
Proliferación Celular , Proteínas Asociadas a Microtúbulos/metabolismo , Mitocondrias/metabolismo , Proteínas de Neoplasias/metabolismo , Neoplasias/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Células A549 , Animales , Humanos , Células MCF-7 , Proteínas de la Membrana , Ratones , Proteínas Asociadas a Microtúbulos/genética , Mitocondrias/genética , Mitocondrias/patología , Células 3T3 NIH , Metástasis de la Neoplasia , Proteínas de Neoplasias/genética , Neoplasias/genética , Neoplasias/patología , Proteínas del Tejido Nervioso/genética , Proteínas de Transporte Vesicular/genéticaRESUMEN
The role of mitochondria in cancer is controversial. Using a genome-wide shRNA screen, we now show that tumours reprogram a network of mitochondrial dynamics operative in neurons, including syntaphilin (SNPH), kinesin KIF5B and GTPase Miro1/2 to localize mitochondria to the cortical cytoskeleton and power the membrane machinery of cell movements. When expressed in tumours, SNPH inhibits the speed and distance travelled by individual mitochondria, suppresses organelle dynamics, and blocks chemotaxis and metastasis, in vivo. Tumour progression in humans is associated with downregulation or loss of SNPH, which correlates with shortened patient survival, increased mitochondrial trafficking to the cortical cytoskeleton, greater membrane dynamics and heightened cell invasion. Therefore, a SNPH network regulates metastatic competence and may provide a therapeutic target in cancer.
Asunto(s)
Cinesinas/metabolismo , Dinámicas Mitocondriales/fisiología , Proteínas Mitocondriales/metabolismo , Metástasis de la Neoplasia/fisiopatología , Proteínas del Tejido Nervioso/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Proteínas de Unión al GTP rho/metabolismo , Regulación hacia Abajo , Regulación Neoplásica de la Expresión Génica , Humanos , Cinesinas/genética , Proteínas de la Membrana , Redes y Vías Metabólicas/fisiología , Proteínas Mitocondriales/genética , Proteínas de Unión al GTP rho/genéticaRESUMEN
Hypoxia is a universal driver of aggressive tumor behavior, but the underlying mechanisms are not completely understood. Using a phosphoproteomics screen, we now show that active Akt accumulates in the mitochondria during hypoxia and phosphorylates pyruvate dehydrogenase kinase 1 (PDK1) on Thr346 to inactivate the pyruvate dehydrogenase complex. In turn, this pathway switches tumor metabolism toward glycolysis, antagonizes apoptosis and autophagy, dampens oxidative stress, and maintains tumor cell proliferation in the face of severe hypoxia. Mitochondrial Akt-PDK1 signaling correlates with unfavorable prognostic markers and shorter survival in glioma patients and may provide an "actionable" therapeutic target in cancer.
Asunto(s)
Reprogramación Celular/fisiología , Mitocondrias/metabolismo , Neoplasias/metabolismo , Neoplasias/patología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Animales , Hipoxia de la Célula/fisiología , Línea Celular Tumoral , Proliferación Celular/fisiología , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos NOD , Ratones Desnudos , Proteínas Serina-Treonina Quinasas/metabolismo , Piruvato Deshidrogenasa Quinasa Acetil-Transferidora , Transducción de SeñalRESUMEN
Mitochondria must buffer the risk of proteotoxic stress to preserve bioenergetics, but the role of these mechanisms in disease is poorly understood. Using a proteomics screen, we now show that the mitochondrial unfoldase-peptidase complex ClpXP associates with the oncoprotein survivin and the respiratory chain Complex II subunit succinate dehydrogenase B (SDHB) in mitochondria of tumor cells. Knockdown of ClpXP subunits ClpP or ClpX induces the accumulation of misfolded SDHB, impairing oxidative phosphorylation and ATP production while activating "stress" signals of 5' adenosine monophosphate-activated protein kinase (AMPK) phosphorylation and autophagy. Deregulated mitochondrial respiration induced by ClpXP targeting causes oxidative stress, which in turn reduces tumor cell proliferation, suppresses cell motility, and abolishes metastatic dissemination in vivo. ClpP is universally overexpressed in primary and metastatic human cancer, correlating with shortened patient survival. Therefore, tumors exploit ClpXP-directed proteostasis to maintain mitochondrial bioenergetics, buffer oxidative stress, and enable metastatic competence. This pathway may provide a "drugable" therapeutic target in cancer.