RESUMEN
PURPOSE: N-myc downstream-regulated gene 2 (NDRG2) is down-regulated in grade-III meningioma [anaplastic meningioma (AM)] and associated with clinically aggressive behavior. Current therapies in the treatment of high-grade meningioma are lacking with limited success. This study aims to validate the effect of NDRG2-targeted therapy using structurally related bioactive triterpene compounds derived from the edible mushroom Ganoderma lucidum (ganoderic acid A:GA-A/ganoderic acid DM:GA-DM) in human AM in relevant pre-clinical models. METHODS: Tissue samples from the AM tumor regions of three human patients and control non-tumor samples were used to analyze the expression pattern of NDRG2. In vitro cell culture and in vivo cell-line-derived orthotopic xenograft animal models of AM were utilized to assess efficacy of treatment with GA-A/DM. RESULTS: Downregulation of NDRG2 expression was observed in surgically resected high-grade meningiomas compared to normal brain. These results prompt us to use NDRG2-targeting agents GA-A/DM. In vitro results showed that 72-h treatments of 25 µM GA-A/DM induced AM cell death, upregulate NDRG2 protein expression, downregulate NDRG2 promoter methylation in meningioma cells as compared to azacitidine and decitabine, the most commonly used demethylating agents. Our results also demonstrated that GA-A/DM does not have any detrimental effect on normal human neurons and arachnoid cells. GA-A/DM promoted apoptotic factors (Bax) while suppressing MMP-9, p-P13K, p-AKT, p-mTOR, and Wnt-2 protein expression. RNAi-mediated knockdown of NDRG2 protein expression increased tumor proliferation, while forced expression of wt-NDRG2 decreased proliferation in an in vitro model. Magnetic resonance (MR) imaging and Hematoxylin (H&E) staining demonstrated gross reduction of tumor volume in GA-A/DM treated mice at 5 weeks when compared with saline-treated orthotopic AM xenografted controls. There was an overall decrease in tumor cell proliferation with increased survival in GA-A/DM-treated animals. Enzyme assays showed that GA-A/DM did not negatively impact hepatic function. CONCLUSION: GA-A/DM may be a promising natural therapeutic reagent in the treatment of AM by suppressing growth via NDRG2 modulation and altering of intracellular signal pathways. We have shown it could potentially be an effective treatment for AM with decreased cellular proliferation in vitro, decreased tumor volume and increased survival in vivo.
Asunto(s)
Ácidos Heptanoicos/farmacología , Lanosterol/análogos & derivados , Neoplasias Meníngeas/metabolismo , Meningioma/metabolismo , Triterpenos/farmacología , Proteínas Supresoras de Tumor/efectos de los fármacos , Anciano , Anaplasia , Animales , Antimetabolitos Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Azacitidina/farmacología , Muerte Celular/efectos de los fármacos , Metilación de ADN/efectos de los fármacos , Decitabina/farmacología , Regulación hacia Abajo , Técnicas de Silenciamiento del Gen , Humanos , Técnicas In Vitro , Lanosterol/farmacología , Metaloproteinasa 9 de la Matriz/efectos de los fármacos , Metaloproteinasa 9 de la Matriz/metabolismo , Neoplasias Meníngeas/patología , Meningioma/patología , Ratones , Ratones SCID , Persona de Mediana Edad , Terapia Molecular Dirigida , Clasificación del Tumor , Fosfatidilinositol 3-Quinasas/efectos de los fármacos , Fosfatidilinositol 3-Quinasas/metabolismo , Fosforilación , Regiones Promotoras Genéticas , Proteínas Proto-Oncogénicas c-akt/efectos de los fármacos , Proteínas Proto-Oncogénicas c-akt/metabolismo , Serina-Treonina Quinasas TOR/efectos de los fármacos , Serina-Treonina Quinasas TOR/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Proteína wnt2/efectos de los fármacos , Proteína wnt2/metabolismo , Ensayos Antitumor por Modelo de Xenoinjerto , Proteína X Asociada a bcl-2/efectos de los fármacos , Proteína X Asociada a bcl-2/metabolismoRESUMEN
PURPOSE: To investigate inhibitory effect of Astragalus polysaccharide (APS) on osteoporosis in ovariectomized rats by regulating FoxO3a/Wnt2 signaling pathway. METHODS: Postmenopausal osteoporosis (PMOP) animal model was developed by excising the bilateral ovaries of rats. The model rats were administered with APS (200 mg/kg, 400 mg/kg, 800 mg/kg) by intragastric administration once daily for 12 weeks. Bone density, bone metabolism index and oxidative stress index were measured in all groups. Furthermore, the regulation of APS of FoxO3a / Wnt2 signaling pathway was observed. RESULTS: APS has an estrogen-like effect, which can increase bone mass, lower serum ALP and BGP values, increase blood calcium content, and increase bone density of the femur and vertebrae in rats. At the same time, APS can increase the bone mineral content of the femur, increase the maximum stress, maximum load and elastic modulus of the ovariectomized rats, improve oxidative stress in rats by increasing the gene expression of ß-catenin and Wnt2 mRNA and inhibiting the gene expression of FoxO3a mRNA. CONCLUSION: Astragalus polysaccharide can effectively alleviate oxidative stress-mediated osteoporosis in ovariectomized rats, which may be related to its regulation of FoxO3a/Wnt2/ß-catenin pathway.
Asunto(s)
Planta del Astrágalo/química , Proteína Forkhead Box O3/efectos de los fármacos , Osteoporosis/tratamiento farmacológico , Polisacáridos/farmacología , Vía de Señalización Wnt/efectos de los fármacos , Animales , Densidad Ósea/efectos de los fármacos , Femenino , Fémur/efectos de los fármacos , Fémur/metabolismo , Proteína Forkhead Box O3/análisis , Expresión Génica/efectos de los fármacos , Proteína-5 Relacionada con Receptor de Lipoproteína de Baja Densidad/análisis , Proteína-5 Relacionada con Receptor de Lipoproteína de Baja Densidad/efectos de los fármacos , Osteoporosis/metabolismo , Ovariectomía , Estrés Oxidativo/efectos de los fármacos , Estrés Oxidativo/fisiología , Distribución Aleatoria , Ratas Sprague-Dawley , Reacción en Cadena en Tiempo Real de la Polimerasa , Valores de Referencia , Reproducibilidad de los Resultados , Resultado del Tratamiento , Vía de Señalización Wnt/fisiología , Proteína wnt2/análisis , Proteína wnt2/efectos de los fármacos , beta Catenina/análisis , beta Catenina/efectos de los fármacosRESUMEN
Abstract Purpose: To investigate inhibitory effect of Astragalus polysaccharide (APS) on osteoporosis in ovariectomized rats by regulating FoxO3a/Wnt2 signaling pathway. Methods: Postmenopausal osteoporosis (PMOP) animal model was developed by excising the bilateral ovaries of rats. The model rats were administered with APS (200 mg/kg, 400 mg/kg, 800 mg/kg) by intragastric administration once daily for 12 weeks. Bone density, bone metabolism index and oxidative stress index were measured in all groups. Furthermore, the regulation of APS of FoxO3a / Wnt2 signaling pathway was observed. Results: APS has an estrogen-like effect, which can increase bone mass, lower serum ALP and BGP values, increase blood calcium content, and increase bone density of the femur and vertebrae in rats. At the same time, APS can increase the bone mineral content of the femur, increase the maximum stress, maximum load and elastic modulus of the ovariectomized rats, improve oxidative stress in rats by increasing the gene expression of β-catenin and Wnt2 mRNA and inhibiting the gene expression of FoxO3a mRNA. Conclusion: Astragalus polysaccharide can effectively alleviate oxidative stress-mediated osteoporosis in ovariectomized rats, which may be related to its regulation of FoxO3a/Wnt2/β-catenin pathway.
Asunto(s)
Animales , Femenino , Osteoporosis/tratamiento farmacológico , Polisacáridos/farmacología , Planta del Astrágalo/química , Vía de Señalización Wnt/efectos de los fármacos , Proteína Forkhead Box O3/efectos de los fármacos , Osteoporosis/metabolismo , Valores de Referencia , Ovariectomía , Distribución Aleatoria , Densidad Ósea/efectos de los fármacos , Expresión Génica/efectos de los fármacos , Reproducibilidad de los Resultados , Resultado del Tratamiento , Ratas Sprague-Dawley , Estrés Oxidativo/efectos de los fármacos , Estrés Oxidativo/fisiología , Proteína wnt2/análisis , Proteína wnt2/efectos de los fármacos , beta Catenina/análisis , beta Catenina/efectos de los fármacos , Fémur/efectos de los fármacos , Fémur/metabolismo , Proteína-5 Relacionada con Receptor de Lipoproteína de Baja Densidad/análisis , Proteína-5 Relacionada con Receptor de Lipoproteína de Baja Densidad/efectos de los fármacos , Reacción en Cadena en Tiempo Real de la Polimerasa , Vía de Señalización Wnt/fisiología , Proteína Forkhead Box O3/análisisRESUMEN
Wnts-related signaling pathways have been reported to play roles in the pathogenesis of stress-induced depression-like behaviors. However, there is relatively few direct evidence to indicate the effect of Wnt ligands on this process. Here, we investigated the role of Wnts in mediating chronic restraint stress (CRS)-induced depression-like behaviors. We found that CRS induced a significant decrease in the expression of Wnt2 and Wnt3 in the ventral hippocampus (VH) but not in the dorsal hippocampus. Knocking down Wnt2 or Wnt3 in the VH led to impaired Wnt/ß-catenin signaling, neurogenesis deficits and depression-like behaviors. In contrast, overexpression of Wnt2 or Wnt3 reversed CRS-induced depression-like behaviors. Moreover, Wnt2 and Wnt3 activated cAMP response element-binding protein (CREB) and there was CREB-dependent positive feedback between Wnt2 and Wnt3. Finally, fluoxetine treatment increased Wnt2 and Wnt3 levels in the VH and knocking down Wnt2 or Wnt3 abolished the antidepressant effect of fluoxetine. Taken together, our study indicates essential roles for Wnt2 and Wnt3 in CRS-induced depression-like behaviors and antidepressant.