ABSTRACT
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.
Subject(s)
Heptanoic Acids/pharmacology , Lanosterol/analogs & derivatives , Meningeal Neoplasms/metabolism , Meningioma/metabolism , Triterpenes/pharmacology , Tumor Suppressor Proteins/drug effects , Aged , Anaplasia , Animals , Antimetabolites, Antineoplastic/pharmacology , Apoptosis/drug effects , Azacitidine/pharmacology , Cell Death/drug effects , DNA Methylation/drug effects , Decitabine/pharmacology , Down-Regulation , Gene Knockdown Techniques , Humans , In Vitro Techniques , Lanosterol/pharmacology , Matrix Metalloproteinase 9/drug effects , Matrix Metalloproteinase 9/metabolism , Meningeal Neoplasms/pathology , Meningioma/pathology , Mice , Mice, SCID , Middle Aged , Molecular Targeted Therapy , Neoplasm Grading , Phosphatidylinositol 3-Kinases/drug effects , Phosphatidylinositol 3-Kinases/metabolism , Phosphorylation , Promoter Regions, Genetic , Proto-Oncogene Proteins c-akt/drug effects , Proto-Oncogene Proteins c-akt/metabolism , TOR Serine-Threonine Kinases/drug effects , TOR Serine-Threonine Kinases/metabolism , Tumor Suppressor Proteins/metabolism , Wnt2 Protein/drug effects , Wnt2 Protein/metabolism , Xenograft Model Antitumor Assays , bcl-2-Associated X Protein/drug effects , bcl-2-Associated X Protein/metabolismABSTRACT
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.
Subject(s)
Astragalus Plant/chemistry , Forkhead Box Protein O3/drug effects , Osteoporosis/drug therapy , Polysaccharides/pharmacology , Wnt Signaling Pathway/drug effects , Animals , Bone Density/drug effects , Female , Femur/drug effects , Femur/metabolism , Forkhead Box Protein O3/analysis , Gene Expression/drug effects , Low Density Lipoprotein Receptor-Related Protein-5/analysis , Low Density Lipoprotein Receptor-Related Protein-5/drug effects , Osteoporosis/metabolism , Ovariectomy , Oxidative Stress/drug effects , Oxidative Stress/physiology , Random Allocation , Rats, Sprague-Dawley , Real-Time Polymerase Chain Reaction , Reference Values , Reproducibility of Results , Treatment Outcome , Wnt Signaling Pathway/physiology , Wnt2 Protein/analysis , Wnt2 Protein/drug effects , beta Catenin/analysis , beta Catenin/drug effectsABSTRACT
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.
Subject(s)
Animals , Female , Osteoporosis/drug therapy , Polysaccharides/pharmacology , Astragalus Plant/chemistry , Wnt Signaling Pathway/drug effects , Forkhead Box Protein O3/drug effects , Osteoporosis/metabolism , Reference Values , Ovariectomy , Random Allocation , Bone Density/drug effects , Gene Expression/drug effects , Reproducibility of Results , Treatment Outcome , Rats, Sprague-Dawley , Oxidative Stress/drug effects , Oxidative Stress/physiology , Wnt2 Protein/analysis , Wnt2 Protein/drug effects , beta Catenin/analysis , beta Catenin/drug effects , Femur/drug effects , Femur/metabolism , Low Density Lipoprotein Receptor-Related Protein-5/analysis , Low Density Lipoprotein Receptor-Related Protein-5/drug effects , Real-Time Polymerase Chain Reaction , Wnt Signaling Pathway/physiology , Forkhead Box Protein O3/analysisABSTRACT
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.
