Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
1.
Brain ; 147(2): 649-664, 2024 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-37703312

RESUMEN

The unfolded protein response (UPR) is rapidly gaining momentum as a therapeutic target for protein misfolding neurodegenerative diseases, in which its overactivation results in sustained translational repression leading to synapse loss and neurodegeneration. In mouse models of these disorders, from Alzheimer's to prion disease, modulation of the pathway-including by the licensed drug, trazodone-restores global protein synthesis rates with profound neuroprotective effects. However, the precise nature of the translational impairment, in particular the specific proteins affected in disease, and their response to therapeutic UPR modulation are poorly understood. We used non-canonical amino acid tagging (NCAT) to measure de novo protein synthesis in the brains of prion-diseased mice with and without trazodone treatment, in both whole hippocampus and cell-specifically. During disease the predominant nascent proteome changes occur in synaptic, cytoskeletal and mitochondrial proteins in both hippocampal neurons and astrocytes. Remarkably, trazodone treatment for just 2 weeks largely restored the whole disease nascent proteome in the hippocampus to that of healthy, uninfected mice, predominantly with recovery of proteins involved in synaptic and mitochondrial function. In parallel, trazodone treatment restored the disease-associated decline in synapses and mitochondria and their function to wild-type levels. In conclusion, this study increases our understanding of how translational repression contributes to neurodegeneration through synaptic and mitochondrial toxicity via depletion of key proteins essential for their function. Further, it provides new insights into the neuroprotective mechanisms of trazodone through reversal of this toxicity, relevant for the treatment of neurodegenerative diseases via translational modulation.


Asunto(s)
Enfermedad de Alzheimer , Enfermedades Neurodegenerativas , Enfermedades por Prión , Priones , Trazodona , Ratones , Animales , Priones/metabolismo , Proteoma/metabolismo , Proteoma/farmacología , Trazodona/farmacología , Trazodona/uso terapéutico , Trazodona/metabolismo , Enfermedades por Prión/tratamiento farmacológico , Enfermedades por Prión/metabolismo , Enfermedades Neurodegenerativas/metabolismo , Sinapsis/metabolismo , Enfermedad de Alzheimer/metabolismo
2.
Urol Int ; 108(1): 49-59, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38035560

RESUMEN

INTRODUCTION: Metformin (MF) intake could be associated with a favorable outcome in sunitinib (SUT)- and axitinib (AX)-treated clear cell renal cell carcinoma (ccRCC) patients. Functionally, MF induces miR-205, a microRNA serving as a tumor suppressor in several cancers. METHODS: Real-time quantitative PCR, viability assays, and Western blotting analyzed MF and SUT/AX effects in RCC4 and 786-O cells. A tetracycline-inducible overexpression model was used to study the role of miR-205 and its known target gene, VEGFA. We analyzed miR-205 and VEGFA within a public and an in-house ccRCC cohort. Human umbilical vein endothelial cell (HUVEC) sprouting assays examined miR-205 effects on angiogenesis initiation. To determine the influence of the von Hippel-Lindau tumor suppressor (VHL), we examined VHLwt reexpressing RCC4 and 786-O cells. RESULTS: Viability assays confirmed a sensitizing effect of MF toward SUT/AX in RCC4 and 786-O cells. Overexpression of miR-205 diminished VEGFA expression - as did treatment with MF. Tumor tissue displayed a downregulation of miR-205 and an upregulation of VEGFA. Accordingly, miR-205 caused less and shorter vessel sprouts in HUVEC assays. Finally, VHLwt-expressing RCC4 and 786-O cells displayed higher miR-205 and lower VEGFA levels. CONCLUSION: Our results support the protective role of MF in ccRCC and offer functional insights into the clinical synergism with tyrosine kinase inhibitors.


Asunto(s)
Carcinoma de Células Renales , Neoplasias Renales , Metformina , MicroARNs , Humanos , Carcinoma de Células Renales/tratamiento farmacológico , Carcinoma de Células Renales/genética , Carcinoma de Células Renales/patología , Neoplasias Renales/tratamiento farmacológico , Neoplasias Renales/genética , Neoplasias Renales/patología , Metformina/farmacología , Línea Celular Tumoral , MicroARNs/genética , Sunitinib/farmacología , Regulación Neoplásica de la Expresión Génica , Proliferación Celular/genética , Factor A de Crecimiento Endotelial Vascular/metabolismo
3.
EMBO J ; 37(22)2018 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-30389661

RESUMEN

Nutrient overload in combination with decreased energy dissipation promotes obesity and diabetes. Obesity results in a hormonal imbalance, which among others activates G protein-coupled receptors utilizing diacylglycerol (DAG) as secondary messenger. Protein kinase D1 (PKD1) is a DAG effector, which integrates multiple nutritional and hormonal inputs, but its physiological role in adipocytes is unknown. Here, we show that PKD1 promotes lipogenesis and suppresses mitochondrial fragmentation, biogenesis, respiration, and energy dissipation in an AMP-activated protein kinase (AMPK)-dependent manner. Moreover, mice lacking PKD1 in adipocytes are resistant to diet-induced obesity due to elevated energy expenditure. Beiging of adipocytes promotes energy expenditure and counteracts obesity. Consistently, deletion of PKD1 promotes expression of the ß3-adrenergic receptor (ADRB3) in a CCAAT/enhancer binding protein (C/EBP)-α- and δ-dependent manner, which leads to the elevated expression of beige markers in adipocytes and subcutaneous adipose tissue. Finally, deletion of PKD1 in adipocytes improves insulin sensitivity and ameliorates liver steatosis. Thus, depletion of PKD1 in adipocytes increases energy dissipation by several complementary mechanisms and might represent an attractive strategy to treat obesity and its related complications.


Asunto(s)
Adipocitos/metabolismo , Adiposidad , Metabolismo Energético , Hígado Graso/metabolismo , Obesidad/metabolismo , Proteína Quinasa C/metabolismo , Grasa Subcutánea/metabolismo , Células 3T3-L1 , Adipocitos/patología , Animales , Proteína delta de Unión al Potenciador CCAAT/genética , Proteína delta de Unión al Potenciador CCAAT/metabolismo , Proteínas Potenciadoras de Unión a CCAAT/genética , Proteínas Potenciadoras de Unión a CCAAT/metabolismo , Hígado Graso/genética , Hígado Graso/patología , Femenino , Humanos , Masculino , Ratones , Ratones Mutantes , Obesidad/genética , Obesidad/patología , Proteína Quinasa C/genética , Receptores Adrenérgicos beta 3/genética , Receptores Adrenérgicos beta 3/metabolismo , Sistemas de Mensajero Secundario/genética , Grasa Subcutánea/fisiología
4.
Int J Mol Sci ; 23(7)2022 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-35409086

RESUMEN

Targeting molecular alterations as an effective treatment for isocitrate dehydrogenase-wildtype glioblastoma (GBM) patients has not yet been established. Sterol-O-Acyl Transferase 1 (SOAT1), a key enzyme in the conversion of endoplasmic reticulum cholesterol to esters for storage in lipid droplets (LD), serves as a target for the orphan drug mitotane to treat adrenocortical carcinoma. Inhibition of SOAT1 also suppresses GBM growth. Here, we refined SOAT1-expression in GBM and IDH-mutant astrocytoma, CNS WHO grade 4 (HGA), and assessed the distribution of LD in these tumors. Twenty-seven GBM and three HGA specimens were evaluated by multiple GFAP, Iba1, IDH1 R132H, and SOAT1 immunofluorescence labeling as well as Oil Red O staining. To a small extent SOAT1 was expressed by tumor cells in both tumor entities. In contrast, strong expression was observed in glioma-associated macrophages. Triple immunofluorescence labeling revealed, for the first time, evidence for SOAT1 colocalization with Iba1 and IDH1 R132H, respectively. Furthermore, a notable difference in the amount of LD between GBM and HGA was observed. Therefore, SOAT1 suppression might be a therapeutic option to target GBM and HGA growth and invasiveness. In addition, the high expression in cells related to neuroinflammation could be beneficial for a concomitant suppression of protumoral microglia/macrophages.


Asunto(s)
Neoplasias de la Corteza Suprarrenal , Carcinoma Corticosuprarrenal , Neoplasias Encefálicas , Glioblastoma , Glioma , Esterol O-Aciltransferasa/metabolismo , Neoplasias Encefálicas/metabolismo , Glioblastoma/metabolismo , Glioma/metabolismo , Humanos , Isocitrato Deshidrogenasa/genética , Mutación
5.
Int J Mol Sci ; 21(2)2020 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-31940827

RESUMEN

Head and neck squamous cell carcinoma (HNSCC) is known to overexpress a variety of receptor tyrosine kinases, such as the HGF receptor Met. Like other malignancies, HNSCC involves a mutual interaction between the tumor cells and surrounding tissues and cells. We hypothesized that activation of HGF/Met signaling in HNSCC influences glucose metabolism and therefore substantially changes the tumor microenvironment. To determine the effect of HGF, we submitted three established HNSCC cell lines to mRNA sequencing. Dynamic changes in glucose metabolism were measured in real time by an extracellular flux analyzer. As expected, the cell lines exhibited different levels of Met and responded differently to HGF stimulation. As confirmed by mRNA sequencing, the level of Met expression was associated with the number of upregulated HGF-dependent genes. Overall, Met stimulation by HGF leads to increased glycolysis, presumably mediated by higher expression of three key enzymes of glycolysis. These effects appear to be stronger in Methigh-expressing HNSCC cells. Collectively, our data support the hypothesized role of HGF/Met signaling in metabolic reprogramming of HNSCC.


Asunto(s)
Carcinoma de Células Escamosas/metabolismo , Reprogramación Celular , Glucólisis , Neoplasias de Cabeza y Cuello/metabolismo , Proteínas Proto-Oncogénicas c-met/metabolismo , Carcinoma de Células Escamosas/genética , Línea Celular Tumoral , Neoplasias de Cabeza y Cuello/genética , Factor de Crecimiento de Hepatocito/metabolismo , Humanos , Proteínas Proto-Oncogénicas c-met/genética
6.
Cell Commun Signal ; 17(1): 87, 2019 07 29.
Artículo en Inglés | MEDLINE | ID: mdl-31358011

RESUMEN

BACKGROUND: The understanding of lysosomes has been expanded in recent research way beyond their view as cellular trash can. Lysosomes are pivotal in regulating metabolism, endocytosis and autophagy and are implicated in cancer. Recently it was discovered that the lysosomal V-ATPase, which is known to induce apoptosis, interferes with lipid metabolism in cancer, yet the interplay between these organelles is poorly understood. METHODS: LC-MS/MS analysis was performed to investigate lipid distribution in cells. Cell survival and signaling pathways were analyzed by means of cell biological methods (qPCR, Western Blot, flow cytometry, CellTiter-Blue). Mitochondrial structure was analyzed by confocal imaging and electron microscopy, their function was determined by flow cytometry and seahorse measurements. RESULTS: Our data reveal that interfering with lysosomal function changes composition and subcellular localization of triacylglycerids accompanied by an upregulation of PGC1α and PPARα expression, master regulators of energy and lipid metabolism. Furthermore, cardiolipin content is reduced driving mitochondria into fission, accompanied by a loss of membrane potential and reduction in oxidative capacity, which leads to a deregulation in cellular ROS and induction of mitochondria-driven apoptosis. Additionally, cells undergo a metabolic shift to glutamine dependency, correlated with the fission phenotype and sensitivity to lysosomal inhibition, most prominent in Ras mutated cells. CONCLUSION: This study sheds mechanistic light on a largely uninvestigated triangle between lysosomes, lipid metabolism and mitochondrial function. Insight into this organelle crosstalk increases our understanding of mitochondria-driven cell death. Our findings furthermore provide a first hint on a connection of Ras pathway mutations and sensitivity towards lysosomal inhibitors.


Asunto(s)
Muerte Celular , Metabolismo de los Lípidos , Mitocondrias/metabolismo , Muramidasa/metabolismo , Línea Celular Tumoral , Humanos , Estrés Oxidativo , ATPasas de Translocación de Protón Vacuolares/antagonistas & inhibidores
7.
Elife ; 112022 09 26.
Artículo en Inglés | MEDLINE | ID: mdl-36155135

RESUMEN

Chlamydia trachomatis (Ctr) can persist over extended times within their host cell and thereby establish chronic infections. One of the major inducers of chlamydial persistence is interferon-gamma (IFN-γ) released by immune cells as a mechanism of immune defence. IFN-γ activates the catabolic depletion of L-tryptophan (Trp) via indoleamine-2,3-dioxygenase (IDO), resulting in persistent Ctr. Here, we show that IFN-γ induces the downregulation of c-Myc, the key regulator of host cell metabolism, in a STAT1-dependent manner. Expression of c-Myc rescued Ctr from IFN-γ-induced persistence in cell lines and human fallopian tube organoids. Trp concentrations control c-Myc levels most likely via the PI3K-GSK3ß axis. Unbiased metabolic analysis revealed that Ctr infection reprograms the host cell tricarboxylic acid (TCA) cycle to support pyrimidine biosynthesis. Addition of TCA cycle intermediates or pyrimidine/purine nucleosides to infected cells rescued Ctr from IFN-γ-induced persistence. Thus, our results challenge the longstanding hypothesis of Trp depletion through IDO as the major mechanism of IFN-γ-induced metabolic immune defence and significantly extends the understanding of the role of IFN-γ as a broad modulator of host cell metabolism.


Asunto(s)
Chlamydia trachomatis , Interferón gamma , Proteínas Proto-Oncogénicas c-myc , Línea Celular , Chlamydia trachomatis/fisiología , Femenino , Glucógeno Sintasa Quinasa 3 beta , Humanos , Indolamina-Pirrol 2,3,-Dioxigenasa/genética , Indolamina-Pirrol 2,3,-Dioxigenasa/metabolismo , Interferón gamma/metabolismo , Fosfatidilinositol 3-Quinasas , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-myc/metabolismo , Nucleósidos de Purina , Pirimidinas , Ácidos Tricarboxílicos , Triptófano/metabolismo
8.
Sci Transl Med ; 14(646): eabj2829, 2022 05 25.
Artículo en Inglés | MEDLINE | ID: mdl-35613281

RESUMEN

Microbial diversity is associated with improved outcomes in recipients of allogeneic hematopoietic cell transplantation (allo-HCT), but the mechanism underlying this observation is unclear. In a cohort of 174 patients who underwent allo-HCT, we demonstrate that a diverse intestinal microbiome early after allo-HCT is associated with an increased number of innate-like mucosal-associated invariant T (MAIT) cells, which are in turn associated with improved overall survival and less acute graft-versus-host disease (aGVHD). Immune profiling of conventional and unconventional immune cell subsets revealed that the prevalence of Vδ2 cells, the major circulating subpopulation of γδ T cells, closely correlated with the frequency of MAIT cells and was associated with less aGVHD. Analysis of these populations using both single-cell transcriptomics and flow cytometry suggested a shift toward activated phenotypes and a gain of cytotoxic and effector functions after transplantation. A diverse intestinal microbiome with the capacity to produce activating ligands for MAIT and Vδ2 cells appeared to be necessary for the maintenance of these populations after allo-HCT. These data suggest an immunological link between intestinal microbial diversity, microbe-derived ligands, and maintenance of unconventional T cells.


Asunto(s)
Microbioma Gastrointestinal , Enfermedad Injerto contra Huésped , Trasplante de Células Madre Hematopoyéticas , Células T Invariantes Asociadas a Mucosa , Humanos , Ligandos
9.
Cancers (Basel) ; 13(6)2021 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-33809510

RESUMEN

Altered metabolic processes contribute to carcinogenesis by modulating proliferation, survival and differentiation. Tumours are composed of different cell populations, with cancer stem-like cells being one of the most prominent examples. This specific pool of cells is thought to be responsible for cancer growth and recurrence and plays a particularly relevant role in glioblastoma (GBM), the most lethal form of primary brain tumours. Here, we have analysed the transcriptome and metabolome of an established GBM cell line (U87) and a patient-derived GBM stem-like cell line (NCH644) exposed to neurosphere or monolayer culture conditions. By integrating transcriptome and metabolome data, we identified key metabolic pathways and gene signatures that are associated with stem-like and differentiated states in GBM cells, and demonstrated that neurospheres and monolayer cells differ substantially in their metabolism and gene regulation. Furthermore, arginine biosynthesis was identified as the most significantly regulated pathway in neurospheres, although individual nodes of this pathway were distinctly regulated in the two cellular systems. Neurosphere conditions, as opposed to monolayer conditions, cause a transcriptomic and metabolic rewiring that may be crucial for the regulation of stem-like features, where arginine biosynthesis may be a key metabolic pathway. Additionally, TCGA data from GBM patients showed significant regulation of specific components of the arginine biosynthesis pathway, providing further evidence for the importance of this metabolic pathway in GBM.

10.
Cell Metab ; 31(1): 62-76, 2020 01 07.
Artículo en Inglés | MEDLINE | ID: mdl-31813823

RESUMEN

Altered lipid metabolism is among the most prominent metabolic alterations in cancer. Enhanced synthesis or uptake of lipids contributes to rapid cancer cell growth and tumor formation. Lipids are a highly complex group of biomolecules that not only constitute the structural basis of biological membranes but also function as signaling molecules and an energy source. Here, we summarize recent evidence implicating altered lipid metabolism in different aspects of the cancer phenotype and discuss potential strategies by which targeting lipid metabolism could provide a therapeutic window for cancer treatment.


Asunto(s)
Metabolismo Energético , Metabolismo de los Lípidos , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Células Madre Neoplásicas/metabolismo , Transducción de Señal/genética , Estrés Fisiológico/genética , Colesterol/biosíntesis , Colesterol/genética , Colesterol/metabolismo , Metabolismo Energético/genética , Ácidos Grasos/biosíntesis , Ácidos Grasos/genética , Ácidos Grasos/metabolismo , Ferroptosis/genética , Humanos , Metabolismo de los Lípidos/genética , Neoplasias/genética , Neoplasias/patología , Células Madre Neoplásicas/patología , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiología , Estrés Fisiológico/efectos de los fármacos , Estrés Fisiológico/fisiología , Microambiente Tumoral/genética
11.
Nat Microbiol ; 5(11): 1390-1402, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32747796

RESUMEN

Obligate intracellular bacteria such as Chlamydia trachomatis undergo a complex developmental cycle between infectious, non-replicative elementary-body and non-infectious, replicative reticulate-body forms. Elementary bodies transform to reticulate bodies shortly after entering a host cell, a crucial process in infection, initiating chlamydial replication. As Chlamydia fail to replicate outside the host cell, it is unknown how the replicative part of the developmental cycle is initiated. Here we show, using a cell-free approach in axenic media, that the uptake of glutamine by the bacteria is crucial for peptidoglycan synthesis, which has a role in Chlamydia replication. The increased requirement for glutamine in infected cells is satisfied by reprogramming the glutamine metabolism in a c-Myc-dependent manner. Glutamine is effectively taken up by the glutamine transporter SLC1A5 and metabolized via glutaminase. Interference with this metabolic reprogramming limits the growth of Chlamydia. Intriguingly, Chlamydia failed to produce progeny in SLC1A5-knockout organoids and mice. Thus, we report on the central role of glutamine for the development of an obligate intracellular pathogenic bacterium and the reprogramming of host glutamine metabolism, which may provide a basis for innovative anti-infection strategies.


Asunto(s)
Infecciones por Chlamydia/metabolismo , Chlamydia trachomatis/fisiología , Glutamina/metabolismo , Peptidoglicano/biosíntesis , Sistema de Transporte de Aminoácidos ASC/genética , Sistema de Transporte de Aminoácidos ASC/metabolismo , Animales , Línea Celular , Infecciones por Chlamydia/microbiología , Chlamydia trachomatis/crecimiento & desarrollo , Chlamydia trachomatis/metabolismo , Regulación de la Expresión Génica , Interacciones Huésped-Patógeno , Humanos , Ratones , Antígenos de Histocompatibilidad Menor/genética , Antígenos de Histocompatibilidad Menor/metabolismo , Quinasas de Proteína Quinasa Activadas por Mitógenos/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-myc/metabolismo , Transducción de Señal
12.
Nat Cancer ; 1(10): 998-1009, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-33479702

RESUMEN

Metabolic reprogramming is a key hallmark of cancer, but less is known about metabolic plasticity of the same tumor at different sites. Here, we investigated the metabolic adaptation of leukemia in two different microenvironments, the bone marrow and the central nervous system (CNS). We identified a metabolic signature of fatty-acid synthesis in CNS leukemia, highlighting Stearoyl-CoA desaturase (SCD1) as a key player. In vivo SCD1 overexpression increases CNS disease, whilst genetic or pharmacological inhibition of SCD1 decreases CNS load. Overall, we demonstrated that leukemic cells dynamically rewire metabolic pathways to suit local conditions and that targeting these adaptations can be exploited therapeutically.


Asunto(s)
Leucemia-Linfoma Linfoblástico de Células Precursoras , Estearoil-CoA Desaturasa , Sistema Nervioso Central/metabolismo , Humanos , Lipogénesis , Estearoil-CoA Desaturasa/genética , Microambiente Tumoral
13.
Cell Rep ; 31(12): 107806, 2020 06 23.
Artículo en Inglés | MEDLINE | ID: mdl-32579932

RESUMEN

Cancer cells display an increased plasticity in their lipid metabolism, which includes the conversion of palmitate to sapienate via the enzyme fatty acid desaturase 2 (FADS2). We find that FADS2 expression correlates with mammalian target of rapamycin (mTOR) signaling and sterol regulatory element-binding protein 1 (SREBP-1) activity across multiple cancer types and is prognostic in some cancer types. Accordingly, activating mTOR signaling by deleting tuberous sclerosis complex 2 (Tsc2) or overexpression of SREBP-1/2 is sufficient to increase FADS2 mRNA expression and sapienate metabolism in mouse embryonic fibroblasts (MEFs) and U87 glioblastoma cells, respectively. Conversely, inhibiting mTOR signaling decreases FADS2 expression and sapienate biosynthesis in MEFs with Tsc2 deletion, HUH7 hepatocellular carcinoma cells, and orthotopic HUH7 liver xenografts. In conclusion, we show that mTOR signaling and SREBP activity are sufficient to activate sapienate metabolism by increasing FADS2 expression. Consequently, targeting mTOR signaling can reduce sapienate metabolism in vivo.


Asunto(s)
Ácido Graso Desaturasas/genética , Regulación Neoplásica de la Expresión Génica , Ácidos Palmíticos/metabolismo , Transducción de Señal , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/biosíntesis , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/metabolismo , Serina-Treonina Quinasas TOR/metabolismo , Animales , Línea Celular Tumoral , Ácido Graso Desaturasas/metabolismo , Humanos , Ratones , Pronóstico , ARN Mensajero/genética , ARN Mensajero/metabolismo , Transcripción Genética
14.
Cancer Metab ; 6: 8, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29942509

RESUMEN

BACKGROUND: Ketogenic diets (KDs) or short-term fasting are popular trends amongst supportive approaches for cancer patients. Beta-hydroxybutyrate (3-OHB) is the main physiological ketone body, whose concentration can reach plasma levels of 2-6 mM during KDs or fasting. The impact of 3-OHB on the biology of tumor cells described so far is contradictory. Therefore, we investigated the effect of a physiological concentration of 3 mM 3-OHB on metabolism, proliferation, and viability of breast cancer (BC) cells in vitro. METHODS: Seven different human BC cell lines (BT20, BT474, HBL100, MCF-7, MDA-MB 231, MDA-MB 468, and T47D) were cultured in medium with 5 mM glucose in the presence of 3 mM 3-OHB at mild hypoxia (5% oxygen) or normoxia (21% oxygen). Metabolic profiling was performed by quantification of the turnover of glucose, lactate, and 3-OHB and by Seahorse metabolic flux analysis. Expression of key enzymes of ketolysis as well as the main monocarboxylic acid transporter MCT2 and the glucose-transporter GLUT1 was analyzed by RT-qPCR and Western blotting. The effect of 3-OHB on short- and long-term cell proliferation as well as chemo- and radiosensitivity were also analyzed. RESULTS: 3-OHB significantly changed the oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) in BT20 cells resulting in a more oxidative energetic phenotype. MCF-7 and MDA-MB 468 cells had increased ECAR only in response to 3-OHB, while the other three cell types remained uninfluenced. All cells expressed MCT2 and GLUT1, thus being able to uptake the metabolites. The consumption of 3-OHB was not strongly linked to mRNA overexpression of key enzymes of ketolysis and did not correlate with lactate production and glucose consumption. Neither 3-OHB nor acetoacetate did interfere with proliferation. Further, 3-OHB incubation did not modify the response of the tested BC cell lines to chemotherapy or radiation. CONCLUSIONS: We found that a physiological level of 3-OHB can change the energetic profile of some BC cell lines. However, 3-OHB failed to influence different biologic processes in these cells, e.g., cell proliferation and the response to common breast cancer chemotherapy and radiotherapy. Thus, we have no evidence that 3-OHB generally influences the biology of breast cancer cells in vitro.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA