RESUMEN
BACKGROUND AND PURPOSE: The aim of this study is to decipher the underlying mechanisms of CCAAT/enhancer-binding protein delta (CEBPD)-enhanced glycolysis as well as the biological significance of CEBPD and MYC coamplification in urothelial carcinoma (UC). METHODS: In vitro analyses were conducted to examine the effects of altered CEBPD or MYC expression on UC cells. The in vivo effects of CEBPD overexpression in a high-glucose environment on tumour growth were investigated in xenografted induced diabetic severe combined immunodeficiency/beige mice. Data mining was used to cross-validate the associations between CEBPD and MYC copy number and transcriptional expression, quantitative reverse transcription-polymerase chain reaction, immunohistochemistry, chromogenic in situ hybridization, and in situ hybridization targeting microRNA were performed on 635 UC patient samples and xenograft samples. UC patient survival in relation to diabetes was validated by using the National Health Insurance Research Database. RESULTS: CEBPD and MYC coamplification (29.6%) occurred at a high frequency, MYC expression promoted chromosomal instability, facilitating CEBPD copy number gain and expression. CEBPD promoted glucose uptake and lactate production by upregulating SLC2A1 and HK2, leading to mitochondrial fission, increased extracellular acidification rate and decreased oxygen consumption rate to fuel cell growth. CEBPD upregulated HK2 expression through multiple regulation pathways including MYC stabilization, suppression of FBXW7 transactivation and MYC-independent transcriptional suppression of hsa-miR-429. Clinical and xenografted experiments confirmed the growth advantage of CEBPD in relation to glucose metabolic dysregulation and the significant correlations between the expression of these genes. CONCLUSIONS: We confirmed that CEBPD has an oncogenic role in UC by activating AKT signalling and initiating metabolic reprogramming from mitochondrial oxidative phosphorylation to glycolysis to satisfy glucose addiction. These novel CEBPD- and MYC-centric multilayered positive feedback loops enhance cancer growth that could complement theranostic approaches.
Asunto(s)
Proteína delta de Unión al Potenciador CCAAT/efectos de los fármacos , Genes myc/efectos de los fármacos , Neoplasias de la Vejiga Urinaria/genética , Urotelio/fisiopatología , Animales , Proliferación Celular/efectos de los fármacos , Modelos Animales de Enfermedad , Retroalimentación Fisiológica/efectos de los fármacos , Retroalimentación Fisiológica/fisiología , Ratones , Urotelio/anomalías , Efecto Warburg en OncologíaRESUMEN
BACKGROUND: Androgen production following exercise has been suggested to contribute anabolic actions of muscle. However, the underlying mechanisms of the androgen receptor (AR) in androgen's action are still unclear. OBJECTIVE: In the present study, we examined androgen/AR-mediated action in exercise, especially for the suppression of myostatin, a potent negative regulator of muscle mass. METHODS: To examine the effects of exercise, we employed low-intensity exercise in mice and electric pulse stimulation (EPS) in C2C12 myotubes. Androgen production by C2C12 myotubes was measured by enzyme-linked immunosorbent assay. To block the action of AR, we pretreated C2C12 myotubes with flutamide. Quantitative real-time polymerase chain reaction was used to determine the expression levels of proteolytic genes including CCAAT/enhancer-binding protein delta (C/EBPδ), myostatin and muscle E3 ubiquitin ligases, as well as myogenic genes such as myogenin and PGC1α. The activation of 5'-adenosine-activated protein kinase and STAT3 was determined by Western blot analysis. RESULTS: Both mRNA and protein levels of AR significantly increased in skeletal muscle of low-intensity exercised mice and C2C12 myotubes exposed to EPS. Production of testosterone and dihydrotestosterone from EPS-treated C2C12 myotubes was markedly increased. Of interest, we found that myostatin was clearly inhibited by EPS, and its inhibition was significantly abrogated when AR was blocked by flutamide. To test how AR suppresses myostatin, we examined the effects of EPS on C/EBPδ because the promoter region of myostatin has several C/EBP recognition sites. C/EBPδ expression was decreased by EPS, and this decrease was negated by flutamide. IL-6 and phospho-STAT3 (pSTAT3) expression, the downstream pathway of myostatin, were decreased by EPS and this was also reversed by flutamide. Similar downregulation of C/EBPδ, myostatin, and IL-6 was seen in skeletal muscle of low-intensity exercised mice. CONCLUSIONS: Muscle AR expression and androgen production were increased by exercise and EPS treatment. As a mechanistical insight, it is suggested that AR inhibited myostatin expression transcriptionally by C/EBPδ suppression, which negatively influences IL-6/pSTAT3 expression and consequently contributes to the prevention of muscle proteolysis during exercise.
Asunto(s)
Proteína delta de Unión al Potenciador CCAAT/genética , Fibras Musculares Esqueléticas/metabolismo , Miostatina/genética , Condicionamiento Físico Animal , Receptores Androgénicos/genética , Antagonistas de Andrógenos/farmacología , Animales , Proteína delta de Unión al Potenciador CCAAT/efectos de los fármacos , Dihidrotestosterona/metabolismo , Estimulación Eléctrica , Flutamida/farmacología , Técnicas In Vitro , Interleucina-6/metabolismo , Ratones , Fibras Musculares Esqueléticas/efectos de los fármacos , Miogenina/efectos de los fármacos , Miogenina/genética , Miostatina/efectos de los fármacos , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma/efectos de los fármacos , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Receptores Androgénicos/metabolismo , Factor de Transcripción STAT3/efectos de los fármacos , Factor de Transcripción STAT3/metabolismo , Transducción de Señal , Testosterona/metabolismo , TranscriptomaRESUMEN
Bioactive compound substances from Grifola frondosa (maitake) inhibited adipocyte differentiation of B(2)C(1) preadipocytes. This compound is not related to MAP kinase (ERK1 and ERK2) cascades or beta-catenin, which inhibit the expression of Glut4, PPARgamma and C/EBPalpha. The compound reduced the expression time of C/EBPbeta and C/EBPdelta. These results suggest that the inhibitory action of these bioactive compounds on adipocyte differentiation is exhibited through preadipocytes. They cannot induce the expression of PPARgamma or C/EBPalpha because of the reduced expression time of C/EBPbeta and C/EBPdelta.
Asunto(s)
Adipocitos/metabolismo , Proteína beta Potenciadora de Unión a CCAAT/efectos de los fármacos , Proteína delta de Unión al Potenciador CCAAT/efectos de los fármacos , Grifola , Extractos Vegetales/farmacología , Animales , Western Blotting , Proteína beta Potenciadora de Unión a CCAAT/genética , Proteína beta Potenciadora de Unión a CCAAT/metabolismo , Proteína delta de Unión al Potenciador CCAAT/genética , Proteína delta de Unión al Potenciador CCAAT/metabolismo , Técnicas de Cultivo de Célula , Diferenciación Celular/genética , Electroforesis en Gel de Poliacrilamida , Regulación de la Expresión Génica/genética , Grifola/química , Ratones , Extractos Vegetales/aislamiento & purificación , ConejosRESUMEN
Cell envelope compounds of bacteria trigger immune and inflammatory reactions by way of chemokines/cytokines. In this study, we demonstrated that pneumococcal peptidoglycan-polysaccharides (PGPS) induced the production of interleukin (IL)-8 by way of nuclear factor (NF)-kappaB, nuclear factor interleukin (NF-IL)6, and activation protein (AP)-1 dependent mechanisms in the human bronchial epithelial cells (NL-20) in a dose- and time-dependent manner in vitro, and the mutation of either the NF-kappaB, NF-IL6, or AP-1 binding sites in the promoter of IL-8 abrogated the IL-8 transcriptional activity. In a similar way, lipopolysaccharides induced the promoter activation of IL-8 in NL-20. However, the PGPS-induced IL-8 promoter activation in rodent middle ear epithelial cells required NF-kappaB and NF-IL6 but not AP-1.