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1.
Toxicol Lett ; 318: 74-85, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31654802

RESUMO

Metabolic flexibility defines the capacity of cells to respond to changes in nutrient status. Mitochondria are important mediators of metabolic flexibility and dysfunction is associated with metabolic inflexibility and pathology. Foodborne toxins are often overlooked as potential factors contributing to metabolic toxicity. Fusaric acid (FA), a neglected mycotoxin, is known to disrupt mitochondrial function. The aim of this study was to investigate the molecular mechanisms underlying a metabolic switch in response to FA. This study investigated the effects of FA on energy homeostasis in cultured human liver (HepG2) cells. HepG2 cells poised to undergo oxidative and glycolytic metabolism were exposed to a range of FA concentrations (4, 63 and 250 µg/mL) for 6 h. We determined mitochondrial toxicity, acetyl CoA levels and cell viability using luminometric, fluorometric and spectrophotometric methods. Expression of metabolic proteins (PDK1, PKM2, phosphorylated-PDH E1α and HIF-1α) and mRNAs (HIF-1α, PKM2, LDHa and PDK1) were determined using western blot and qPCR respectively. Our data connects a constitutive expression of HIF-1α in response to FA, to the inhibition of pyruvate decarboxylation through up-regulation of PDK-1 and phosphorylation of Pyruvate Dehydrogenase E1α subunit. Moreover, we highlight the potential of FA to induce a glucose "addiction" and phenotype reminiscent of the Warburg effect. The findings provide novel insights into the impact of this neglected foodborne mycotoxin in the dysregulation of energy metabolism.


Assuntos
Plasticidade Celular/efeitos dos fármacos , Microbiologia de Alimentos , Ácido Fusárico/toxicidade , Glicólise/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Mitocôndrias Hepáticas/efeitos dos fármacos , Células Hep G2 , Hepatócitos/metabolismo , Hepatócitos/patologia , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Mitocôndrias Hepáticas/metabolismo , Mitocôndrias Hepáticas/patologia , Fenótipo , Fosforilação , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Piruvato Desidrogenase (Lipoamida)/metabolismo
2.
Biochemistry (Mosc) ; 84(10): 1117-1128, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31694508

RESUMO

According to modern concepts, tumor formation is associated with impairments in the structure of protooncogenes and/or deactivation of suppressor genes, regardless of the nature of carcinogenic factor. As a consequence, unregulated oncoproteins activate extracellular proteases, resulting in the destruction of the extracellular matrix, which facilitates cell invasion, deterioration of the cell-cell contacts, and metastasis. Tumor development requires activation of certain transcription factors; however, many oncoproteins are not transcription factors. It can be assumed that these oncoproteins are not the ultimate effectors of tumor development, but rather transmitters of the carcinogenic signal to the transcription factors promoting tumorigenesis. Here, we describe the mechanisms of carcinogenesis caused by various oncogenes/oncoproteins. We conclude that the common feature of these mechanisms is stimulation of aerobic glycolysis (Warburg effect) regulated, as a rule, through the activation of the HIFα transcription factor. The role of aerobic glycolysis at the early stages of carcinogenesis is discussed.


Assuntos
Carcinogênese/metabolismo , Glicólise , Neoplasias/metabolismo , Proteínas Oncogênicas/metabolismo , Animais , Carcinogênese/genética , Humanos , Neoplasias/genética , Proteínas Oncogênicas/genética
3.
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue ; 31(9): 1167-1169, 2019 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-31657347

RESUMO

OBJECTIVE: Metabolic reprogramming is the response of cells to environmental changes, such as cell activation, proliferation and differentiation, which involves changes in metabolism-related enzymes, metabolites and metabolic pathways. Sepsis-associated immune cells undergo metabolic reprogramming in response to inflammatory signals, which not only provides biological energy and biosynthesis requirements, but also determines cell fate and function in a highly specific way. In this paper, the changes in glycolysis, tricarboxylic acid cycle, oxidative phosphorylation and other glucose metabolism pathways of macrophages, T lymphocytes, dendritic cells, neutrophils and other sepsis related immune cells are described, so as to provide feasibility for future research and metabolic therapy.


Assuntos
Glicólise , Sepse , Células Dendríticas , Glicogênio , Humanos , Fosforilação Oxidativa
4.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 27(5): 1387-1394, 2019 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-31607288

RESUMO

OBJECTIVE: To investigate the effect of metformin on the proliferation, apoptosis and energy metabolism of acute myeloid leukemia (AML) K562 cells and the possible mechanism. METHODS: Different doses (0, 5, 10, 20 and 30 mmol/L) of metformin was added into the K562 cells, which were cultivated for 24 h, 48 h and 72 h. The inverted optical microscope was used to observe the cell growth, CCK 8 was used to detect the cell vitality. The appropriate metformin doses (0, 10, 20 and 30 mmol/L) and the best time (48 h) were selected for subsequent experiments. The flow cytometer with Annexin V-FITC /PI doulde staining was used to detect apoptosis; the glucose detection kit and lactate detection kit were used to detect glucose consumption and lactate production; fluorescence quantitative PCR was used to detect glycolysis-related gene expression, and Western blot was used to detect protein expression. RESULTS: Metformin inhibited the proliferation of K562 cells in a dose-dependent manner (r=0.92), and the relative survival in the 30 mmol/L group was as low as 19.84% at 72 h. When treated with metformin for 48 h, the apoptosis rates of 0, 10, 20 and 30 mmol/L groups were 5.14%, 12.19%, 26.29% and 35.5%, respectively. Compared with the control group, the glucose consumption and lactate secretion of K562 cells treated with metformin were significantly reduced (P<0.05), and showed a dose-dependent effect(r=0.94,r=0.93,respectively). Metformin inhibited the expression of GLUT1, LDHA, ALDOA, PDK1, and PGK1 genes of K562 cells (P<0.05) showing a dose-dependent manner(r=0.83,r=0.80,r=0.72,r=0.76,r=0.73,respectively). Metformin inhibited the expression of P-Akt, P-S6, GLUT1, LDHA proteins of K562 cells(P<0.05), showing a dose-dependent relationship(r=0.80,r=0.92,r=0.83,r=0.92,respectively). CONCLUSION: Metformin can inhibit the growth and proliferation of K562 cells and promote the apoptosis of K562 cells by inhibiting glycolysis energy metabolism. PI3K/Akt/mTOR signaling pathway may be one of the molecular mechanisms of metformin on k562 cells.


Assuntos
Metformina/farmacologia , Apoptose , Proliferação de Células , Glicólise , Humanos , Células K562 , Fosfatidilinositol 3-Quinases
5.
Nature ; 574(7779): 575-580, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31645732

RESUMO

The Warburg effect, which originally described increased production of lactate in cancer, is associated with diverse cellular processes such as angiogenesis, hypoxia, polarization of macrophages and activation of T cells. This phenomenon is intimately linked to several diseases including neoplasia, sepsis and autoimmune diseases1,2. Lactate, which is converted from pyruvate in tumour cells, is widely known as an energy source and metabolic by-product. However, its non-metabolic functions in physiology and disease remain unknown. Here we show that lactate-derived lactylation of histone lysine residues serves as an epigenetic modification that directly stimulates gene transcription from chromatin. We identify 28 lactylation sites on core histones in human and mouse cells. Hypoxia and bacterial challenges induce the production of lactate by glycolysis, and this acts as a precursor that stimulates histone lactylation. Using M1 macrophages that have been exposed to bacteria as a model system, we show that histone lactylation has different temporal dynamics from acetylation. In the late phase of M1 macrophage polarization, increased histone lactylation induces homeostatic genes that are involved in wound healing, including Arg1. Collectively, our results suggest that an endogenous 'lactate clock' in bacterially challenged M1 macrophages turns on gene expression to promote homeostasis. Histone lactylation thus represents an opportunity to improve our understanding of the functions of lactate and its role in diverse pathophysiological conditions, including infection and cancer.


Assuntos
Epigênese Genética , Glicólise/genética , Histonas/química , Histonas/metabolismo , Ácido Láctico/metabolismo , Acetilação , Sequência de Aminoácidos , Animais , Linhagem Celular Tumoral , Cromatina/química , Cromatina/genética , Cromatina/metabolismo , Homeostase , Humanos , Hipóxia/metabolismo , Lisina/química , Lisina/metabolismo , Macrófagos/metabolismo , Macrófagos/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Reprodutibilidade dos Testes , Transcrição Genética
6.
J Agric Food Chem ; 67(38): 10637-10645, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31513389

RESUMO

Previous studies have shown that selenite, a representative of inorganic form selenium, exerts its anticancer effect by inducing apoptosis in androgen-dependent LNCaP prostate cancer cells, but few studies have determined the nature of cell death induced by selenite in metastatic androgen-refractory PC-3 cells. Our study showed that necrosis-like cell death rather than apoptosis, pyroptosis, or autophagic cell death was caused by selenite in PC-3 cells. Mechanistically, this type of cell death was caused by ATP depletion (26.28 ± 3.39 nmol/mg of control versus 9.12 ± 2.44 nmol/mg of 10 µM selenite treatment) that resulted from phosphofructokinase activity reduction (100.17 ± 0.17% of control versus 21.74 ± 6.65% of 10 µM selenite treatment). Our study also showed that ROS production is necessary for the decrease in cellular ATP levels and in phosphofructokinase activity. To our knowledge, this is the first study showing that selenite can induce necrosis-like cell death in PC-3 cells. Our findings support selenite as an effective compound for the therapy of apoptosis-resistant prostate cancer.


Assuntos
Morte Celular/efeitos dos fármacos , Glicólise/efeitos dos fármacos , Neoplasias da Próstata/fisiopatologia , Ácido Selenioso/farmacologia , Trifosfato de Adenosina/metabolismo , Autofagia/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Masculino , Fosfofrutoquinases/metabolismo , Neoplasias da Próstata/metabolismo
7.
Isr Med Assoc J ; 21(7): 504, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31507133

RESUMO

BACKGROUND: Klotho is a transmembrane protein that can be shed and can act as a circulating hormone in three forms: soluble klotho (KL1 + KL2), KL1, and KL2. Klotho was discovered as a gene implicated in aging through inhibition of the IGF-I pathway. Our laboratory discovered the role of klotho as a tumor suppressor in breast cancer and other malignancies. Furthermore, we showed that the KL1 domain mediates this activity. Altered cancer cell metabolism is a hallmark of cancer and our lab demonstrated various effects of klotho on breast cancer cell metabolism. Thus, klotho inhibited glycolysis and activated adenosine monophosphate activating kinase (AMPK), an energy sensor pathway. Moreover, inhibition of AMPK reduced the tumor suppressor activity of klotho. OBJECTIVES: To assess the effect of KL1 on breast tumor cells metabolism, as KL1 possesses the tumor suppressor activity of klotho. METHODS: We used MCF-7 breast cancer cells treated with soluble or over-expressed KL1 and klotho. Glycolysis was assessed by measuring mRNA levels of key glycolytic enzymes using reverse transcription polymerase chain reaction and by measuring lactate and glucose levels in media. The AMPK pathway was studied by monitoring AMPK phosphorylation as well as its down-stream target, acetyl-CoA carboxylase, using western blotting. Wound healing assay was used to assess cell migration. RESULTS: KL1 treatment reduced glycolytic enzymes mRNA levels and the activity of hexokinase, similar to klotho treatment. Furthermore, KL1 reduced glucose uptake and decreased lactate production. KL1 elevated phosphorylated acetyl-CoA carboxylase and phosphorylated AMPK levels. Inhibition AMPK (using a mutant AMPK activator) stopped KL1 from inhibiting cell migration, suggesting AMPK underlies klotho's tumor suppressor activity. CONCLUSIONS: Our data indicate KL1 as a regulator of metabolic activity in breast cancer and suggest that metabolic alterations underlie KL1 tumor suppressor activities. Furthermore, as KL1 and klotho share a similar effect on cell metabolism, our results further support the central role KL1 domain plays in klotho's tumor suppressor activity.


Assuntos
Neoplasias da Mama/metabolismo , Glucuronidase/metabolismo , Glicólise/fisiologia , Proteínas Quinases Ativadas por AMP/metabolismo , Movimento Celular/fisiologia , Feminino , Humanos , Células MCF-7 , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
8.
Adv Exp Med Biol ; 1178: 25-38, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31493220

RESUMO

Schizophrenia is a severe and debilitating psychiatric disorder believed to have neurodevelopmental origins. Several studies have associated energy metabolism dysfunction with the disorder, mostly related to glycolysis alterations. Glucose is the obligatory energy substrate of the brain and glycolysis is the first step for its metabolism. This takes place predominantly in glial cells, astrocytes and oligodendrocytes, whereas neurons present a predominant oxidative profile. Thus, glial cells generate either lactate or pyruvate to neurons for ATP production. In addition, some aspects of schizophrenia may reflect an advanced aging phenotype with effects on various neural cell types at different stages of the disease. Given the role of glial cells in brain energy metabolism, the association of glycolysis dysfunction and the accelerated aging of neuronal cells in schizophrenia, studies focusing on those aspects can yield important insights into the causes and implications of the disorder. In turn, this may lead to novel therapeutic strategies for improved treatment of individuals suffering with this disorder.


Assuntos
Envelhecimento , Glicólise , Neuroglia , Esquizofrenia , Metabolismo Energético , Glucose/metabolismo , Humanos , Neuroglia/metabolismo , Fenótipo , Esquizofrenia/fisiopatologia
9.
Zhejiang Da Xue Xue Bao Yi Xue Ban ; 48(3): 296-302, 2019 May 25.
Artigo em Chinês | MEDLINE | ID: mdl-31496162

RESUMO

OBJECTIVE: To investigate the effects of high dose vitamin C (VC) on proliferation of breast cancer cells and to explore its mechanisms. METHODS: Human breast cancer cells Bcap37 and MDA-MB-453 were treated with VC at low dose (0.01 mmol/L), medium dose (0.10 mmol/L) and high dose (2.00 mmol/L). Cell proliferation was determined with CCK-8 assay, protein expression was evaluated by Western blot, and the secretion of lactic acid in tumor cells was detected by colorimetric method. Bcap37 cells were inoculated in nude mice, and tumor baring nude mice were intraperitoneally injected with high VC(4 g/kg, VC group, n=5)or normal saline (control group, n=5) for 24 d. Tumor weight and body weight were calculated. RESULTS: In vitro experiments demonstrated that high dose VC significantly inhibited cell proliferation in Bcap37 and MDA-MB-453 cells (all P<0.01); the expressions of Glut1 and mTOR signaling pathway-related proteins were decreased (all P<0.05); and the secretion of lactic acid was also markedly reduced (all P<0.05). In vivo experiment showed that the tumor weight was decreased in mice treated with high-dose VC as compared with control group (P<0.05), but no difference in body weights between two groups was observed. CONCLUSIONS: High dose VC may inhibit proliferation of breast cancer cells both in vitro and in vivo through reducing glycolysis and protein synthesis.


Assuntos
Ácido Ascórbico , Neoplasias da Mama , Glicólise , Biossíntese de Proteínas , Animais , Ácido Ascórbico/farmacologia , Neoplasias da Mama/tratamento farmacológico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Glicólise/efeitos dos fármacos , Humanos , Camundongos , Camundongos Nus , Biossíntese de Proteínas/efeitos dos fármacos
10.
Cancer Immunol Immunother ; 68(9): 1537-1545, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31482306

RESUMO

PURPOSE: To evaluate the clinical-pathological and prognostic significance of the circulating PD-L1 level in patients with surgically treated NSCLC, by combining data for PD-L1 expression with other immune-related markers and tumor metabolism. METHODS: Overall, 40 patients with resected NSCLC (stage Ia-IIIa) who had preoperative blood storage and underwent staging PET/CT were enrolled for the study. In all cases, we determined plasma levels of PD-L1 (pg/ml), immune-reactive areas (IRA %) covered by CD3, CD68, CD20, CD8, PD-1, and PD-L1 in the tumor specimen, and metabolic parameters on PET, i.e., SUVmax, SUVpeak, metabolic tumor volume (MTV), and total lesion glycolysis (TLG). Variables were statistically analyzed to establish their association with disease-free survival (DFS). RESULTS: The circulating levels of PD-L1 in the bloodstream could be determined in 38/40 (95%) samples. The mean and median expression levels were 34.86 pg/ml and 24.83 pg/ml, respectively. We did not find any statistically significant correlation between circulating PD-L1 and tissue expression of PD-L1/PD-1. Some mild degree of positive correlation was determined between tissue PD-L1 and SUVmax (ρ = 0.390; p = 0.0148). Hierarchical clustering combining circulating, tissue, and metabolic parameters identified clusters with high metabolic tumor burden or high expression of plasma PD-L1 levels (Z score ≥ 2) as having a poor DFS (p = 0.033). The multivariate analysis detected stage and metabolism (i.e., SUVmax and SUVpeak) as independent prognostic factors for DFS. CONCLUSION: Plasma levels of PD-L1 are independent of the expression of PD-1/PD-L1 in NSCLC tumor tissue and, when combined with other clinical-pathological parameters, allow for the identification of clusters with different outcomes.


Assuntos
Antígeno B7-H1/metabolismo , Proteínas Sanguíneas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Neoplasias Pulmonares/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígeno B7-H1/genética , Proteínas Sanguíneas/genética , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Feminino , Regulação Neoplásica da Expressão Gênica , Glicólise , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/mortalidade , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Análise de Sobrevida , Resultado do Tratamento , Carga Tumoral
11.
Nat Chem Biol ; 15(10): 1001-1008, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31548693

RESUMO

Glycolysis plays a central role in producing ATP and biomass. Its control principles, however, remain incompletely understood. Here, we develop a method that combines 2H and 13C tracers to determine glycolytic thermodynamics. Using this method, we show that, in conditions and organisms with relatively slow fluxes, multiple steps in glycolysis are near to equilibrium, reflecting spare enzyme capacity. In Escherichia coli, nitrogen or phosphorus upshift rapidly increases the thermodynamic driving force, deploying the spare enzyme capacity to increase flux. Similarly, respiration inhibition in mammalian cells rapidly increases both glycolytic flux and the thermodynamic driving force. The thermodynamic shift allows flux to increase with only small metabolite concentration changes. Finally, we find that the cellulose-degrading anaerobe Clostridium cellulolyticum exhibits slow, near-equilibrium glycolysis due to the use of pyrophosphate rather than ATP for fructose-bisphosphate production, resulting in enhanced per-glucose ATP yield. Thus, near-equilibrium steps of glycolysis promote both rapid flux adaptation and energy efficiency.


Assuntos
Metabolismo Energético/fisiologia , Glicólise , Animais , Linhagem Celular , Clostridium acetobutylicum , Clostridium cellulolyticum , Escherichia coli/classificação , Escherichia coli/metabolismo , Glucose/metabolismo , Homeostase , Camundongos , Nitrogênio , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismo
12.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 36(4): 691-695, 2019 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-31441273

RESUMO

Tumor cells have unique energy metabolism phenomena, namely high glucose absorption, aerobic glycolysis and high lactic acid production, which are characterized by down-regulation of related proteins involved in oxidative metabolism in tumor cells, and up-regulation of glucose transporters and monocarboxylate transporters. Studies have shown that drugs that target tumor cell glucose metabolism have the ability to selectively kill tumor cells, bringing new hope for tumor treatment. Tumor stem cells are considered to be the root cause of tumor recurrence, metastasis and poor prognosis, and their energy metabolism characteristics have not yet been agreed. Studies have shown that reversing the energy metabolism of tumor stem cells can increase their chemosensitivity. This article reviews recent studies on tumor and tumor stem cell glucose metabolism and the opportunities and challenges of tumor treatment through targeting glucose metabolism, which might provide new ideas and opportunities for clinical tumor therapy.


Assuntos
Metabolismo Energético , Glicólise , Neoplasias/metabolismo , Células-Tronco Neoplásicas/metabolismo , Glucose/metabolismo , Humanos , Ácido Láctico/metabolismo
13.
Life Sci ; 233: 116730, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31390552

RESUMO

AIMS: Dihydroartemisinin (DHA) exhibits potential anticancer activity. However, the biological functions of DHA in prostate cancer remain largely unexplored. In this study, we aim to investigate the anti-proliferative effect and glycolysis regulation of DHA on prostate cancer cell LNCaP. MAIN METHODS: Cell proliferative activity and apoptosis inducing were detected. The gene expression was detected by mRNA microarray and results were analyzed by GO and KEGG pathway database. Expressions of glycolysis key enzymes and PI3K/AKT/HIF-1α were detected by Western blot. KEY FINDINGS: Results indicated that DHA could inhibit the LNCaP cell proliferation considerably and induce cell apoptosis. mRNA microarray showed 1293 genes were upregulated and 2322 genes were downregulated. GO and KEGG enrichment analysis suggested that glycolysis pathway was correlated with DHA inhibited the proliferation on the LNCaP cell. Western blot results showed that DHA can decrease GLUT1 and regulatory enzymes of glycolytic pathway expression probably by suppressing the activity of the intracellular Akt/mTOR and HIF-1 α. SIGNIFICANCE: Experimental validation results indicate that DHA treatment can inhibit the LNCaP cell proliferation and induce apoptosis, which may be related to glycolysis inhibition.


Assuntos
Artemisininas/farmacologia , Biomarcadores Tumorais/metabolismo , Glicólise/efeitos dos fármacos , Subunidade alfa do Fator 1 Induzível por Hipóxia/antagonistas & inibidores , Fosfatidilinositol 3-Quinases/antagonistas & inibidores , Neoplasias da Próstata/tratamento farmacológico , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Antimaláricos/farmacologia , Apoptose , Biomarcadores Tumorais/genética , Proliferação de Células , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Masculino , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Células Tumorais Cultivadas
14.
Nat Immunol ; 20(9): 1208-1219, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31384057

RESUMO

Regulatory T cells (Treg cells) deficient in the transcription factor Foxp3 lack suppressor function and manifest an effector T (Teff) cell-like phenotype. We demonstrate that Foxp3 deficiency dysregulates metabolic checkpoint kinase mammalian target of rapamycin (mTOR) complex 2 (mTORC2) signaling and gives rise to augmented aerobic glycolysis and oxidative phosphorylation. Specific deletion of the mTORC2 adaptor gene Rictor in Foxp3-deficient Treg cells ameliorated disease in a Foxo1 transcription factor-dependent manner. Rictor deficiency re-established a subset of Treg cell genetic circuits and suppressed the Teff cell-like glycolytic and respiratory programs, which contributed to immune dysregulation. Treatment of Treg cells from patients with FOXP3 deficiency with mTOR inhibitors similarly antagonized their Teff cell-like program and restored suppressive function. Thus, regulatory function can be re-established in Foxp3-deficient Treg cells by targeting their metabolic pathways, providing opportunities to restore tolerance in Treg cell disorders.


Assuntos
Reprogramação Celular/imunologia , Fatores de Transcrição Forkhead/genética , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismo , Proteína Companheira de mTOR Insensível à Rapamicina/genética , Linfócitos T Reguladores/imunologia , Animais , Células Cultivadas , Feminino , Regulação da Expressão Gênica , Glicólise/fisiologia , Humanos , Masculino , Alvo Mecanístico do Complexo 2 de Rapamicina/antagonistas & inibidores , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fosforilação Oxidativa , Transdução de Sinais , Linfócitos T Reguladores/citologia
16.
BMC Bioinformatics ; 20(1): 442, 2019 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-31455206

RESUMO

BACKGROUND: Contemporary biological observations have revealed a large variety of mechanisms acting during the expansion of a tumor. However, there are still many qualitative and quantitative aspects of the phenomenon that remain largely unknown. In this context, mathematical and computational modeling appears as an invaluable tool providing the means for conducting in silico experiments, which are cheaper and less tedious than real laboratory experiments. RESULTS: This paper aims at developing an extensible and computationally efficient framework for in silico modeling of tumor growth in a 3-dimensional, inhomogeneous and time-varying chemical environment. The resulting model consists of a set of mathematically derived and algorithmically defined operators, each one addressing the effects of a particular biological mechanism on the state of the system. These operators may be extended or re-adjusted, in case a different set of starting assumptions or a different simulation scenario needs to be considered. CONCLUSION: In silico modeling provides an alternative means for testing hypotheses and simulating scenarios for which exact biological knowledge remains elusive. However, finer tuning of pertinent methods presupposes qualitative and quantitative enrichment of available biological evidence. Validation in a strict sense would further require comprehensive, case-specific simulations and detailed comparisons with biomedical observations.


Assuntos
Modelos Biológicos , Modelos Teóricos , Neoplasias/patologia , Algoritmos , Proliferação de Células , Simulação por Computador , Difusão , Glucose/metabolismo , Glicólise , Humanos , Necrose , Neoplasias/irrigação sanguínea , Neovascularização Patológica/patologia , Oxigênio/metabolismo , Fatores de Tempo , Remodelação Vascular
17.
Clin Nucl Med ; 44(8): e479-e483, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31274628

RESUMO

F-FDG PET/CT imaging is an important diagnostic tool for accurate staging and assessment of response to neoadjuvant chemotherapy (NACT) in patients with locally advanced breast carcinoma (LABC). However, F-FDG being non-specific marker, it also accumulates in inflammatory conditions, leading to false positive results. Angiogenesis, an essential characteristic for tumor development, intrusion and metastasis can be imaged using Ga-labeled RGD tripeptide. We here depict a series of clinically staged LABC patients who underwent both Ga-DOTA-RGD2 and F-FDG PET/CT imaging for staging and illustrate the similarities and significant differences between the two tracers.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Glicólise , Neovascularização Patológica/diagnóstico por imagem , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons , Neoplasias da Mama/irrigação sanguínea , Neoplasias da Mama/metabolismo , Feminino , Fluordesoxiglucose F18 , Humanos , Pessoa de Meia-Idade , Estadiamento de Neoplasias
18.
Life Sci ; 232: 116679, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31340168

RESUMO

AIMS: Amplified in liver cancer 1 gene (ALC1), a recently identified oncogene, was reported to be overexpressed in esophageal cancer cell lines and identified as a target oncogene in esophageal cancer pathogenesis. However, little literature is available to illustrate its significance in cisplatin resistance of esophageal squamous cell carcinoma (ESCC) cells. The aim of the current study was to investigate the effect of ALC1 on cisplatin cytotoxicity of ESCC cells and to study the potential mechanisms. MAIN METHODS: ALC1 at mRNA and protein levels were detected by qRT-PCR and western blot, respectively. Cell viability was evaluated using CCK-8 assay. Apoptosis was assessed using caspase-3/7 activity assay and flow cytometry analysis. Glycolysis level was evaluated by measuring glucose consumption and lactate production. The protein levels of p-protein kinase B (Akt) and Akt were determined by western blot. KEY FINDINGS: ALC1 was highly expressed in ESCC cells compared with human normal esophageal epithelial Het-1A cells. ALC1 knockdown suppressed the viability, induced apoptosis and enhanced cisplatin cytotoxicity in ESCC cells. In addition, ALC1 knockdown inhibited glycolysis and inactivated the phosphatidylinositol 3-kinase (PI3K)/Akt pathway in ESCC cells. Mechanistically, activation of the PI3K/Akt pathway by 740Y-P blocked the effects of ALC1 knockdown on cisplatin cytotoxicity and glycolysis in ESCC cells. In contrast, inhibition of the PI3K/Akt pathway by LY294002 or glycolysis by 2-deoxyglucose resisted the effect of ALC1 overexpression on cisplatin cytotoxicity in ESCC cells. SIGNIFICANCE: ALC1 knockdown enhanced cisplatin cytotoxicity of ESCC cells by inhibition of glycolysis through inactivation of the PI3K/Akt pathway.


Assuntos
Antineoplásicos/farmacologia , Carcinoma de Células Escamosas/patologia , Cisplatino/farmacologia , DNA Helicases/genética , Proteínas de Ligação a DNA/genética , Neoplasias Esofágicas/patologia , Técnicas de Silenciamento de Genes , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Apoptose , Carcinoma de Células Escamosas/enzimologia , Carcinoma de Células Escamosas/metabolismo , Ativação Enzimática , Neoplasias Esofágicas/enzimologia , Neoplasias Esofágicas/metabolismo , Glicólise , Humanos , Células Tumorais Cultivadas
19.
Int J Nanomedicine ; 14: 4801-4816, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31308659

RESUMO

Background: Silver nanoparticles (AgNPs) inhibit the proliferation of various fungi; however, their mechanisms of action remain poorly understood. To better understand the inhibitory mechanisms, we focused on the early events elicited by 5 nm AgNPs in pathogenic Candida albicans and non-pathogenic Saccharomyces cerevisiae. Methods: The effect of 5 nm and 100 nm AgNPs on fungus cell proliferation was analyzed by growth kinetics monitoring and spot assay. We examined cell cycle progression, reactive oxygen species (ROS) production, and cell death using flow cytometry. Glucose uptake was assessed using tritium-labeled 2-deoxyglucose. Results: The growth of both C. albicans and S. cerevisiae was suppressed by treatment with 5 nm AgNPs but not with 100 nm AgNPs. In addition, 5 nm AgNPs induced cell cycle arrest and a reduction in glucose uptake in both fungi after 30 minutes of culture in a dose-dependent manner (P<0.05). However, in C. albicans only, an increase in ROS production was detected after exposure to 5 nm AgNPs. Concordantly, an ROS scavenger blocked the effect of 5 nm AgNPs on the cell cycle and glucose uptake in C. albicans only. Furthermore, the growth-inhibition effect of 5 nm AgNPs was not greater in S. cerevisiae mutant strains deficient in oxidative stress response genes than it was in wild type. Finally, 5 nm AgNPs together with a glycolysis inhibitor, 3-bromopyruvate, synergistically enhanced cell death in C. albicans (P<0.05) but not in S. cerevisiae. Conclusion: AgNPs exhibit antifungal activity in a manner that may or may not be ROS dependent, according to the fungal species. The combination of AgNPs with 3-bromopyruvate may be more useful against infection with C. albicans.


Assuntos
Candida albicans/citologia , Ciclo Celular/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Piruvatos/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Saccharomyces cerevisiae/citologia , Prata/farmacologia , Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Candida albicans/crescimento & desenvolvimento , Morte Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Parede Celular/efeitos dos fármacos , Parede Celular/genética , Depuradores de Radicais Livres/farmacologia , Fase G1/efeitos dos fármacos , Genes Fúngicos , Glucose/metabolismo , Glicólise/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/genética , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento
20.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 35(6): 491-497, 2019 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-31292052

RESUMO

Objective To investigate the effect of tumor microenvironment on the metabolism and function of myeloid-derived suppressor cells (MDSCs). Methods The spleen-derived MDSCs of lung cancer xenograft mice were isolated by immunomagnetic beads. After treated by Lewis tumor cell conditioned medium (TCCM) for 48 hours, real-time PCR was used to detect the mRNA levels of lactate dehydrogenase A (LDHA), glucose transporter-1 (GLUT1) and hypoxia-inducible factor 1α (HIF-1α). The hexokinase (HK) method was used to detect the concentration of glucose; the lactic acid test kit was used to detect the content of lactic acid which was the final production of glycolysis; and the 5, 6-carboxyfluorescein diacetate succinimiyl ester (CFSE) staining combined with flow cytometry was used to detect the immunosuppressive function of MDSCs on the proliferation of CD4+ T cells. Arginase kit was used to detect arginase 1 (ARG1) activity of MDSCs, and nitric oxide kit was used to detect the level of inducible nitric oxide synthase (iNOS). Results Compared with the untreated group, the mRNA levels of LDHA, GLUT1 and HIF-1α were up-regulated; the activity of ARG1 and the level of iNOS significantly increased; the immunosuppressive function of MDSCs on the proliferation of CD4+ T cells was significantly enhanced after the treatment of TCCM. Conclusion TCCM can activate the glycolytic pathway, up-regulate the immunosuppressive function on the proliferation of CD4+ T cells and the release of immunosuppressive effector molecule of MDSCs.


Assuntos
Meios de Cultivo Condicionados/química , Glicólise , Imunossupressão , Células Supressoras Mieloides/citologia , Microambiente Tumoral , Animais , Linfócitos T CD4-Positivos/citologia , Neoplasias Pulmonares , Camundongos , Transplante de Neoplasias
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