scholarly journals OS6.2 Loss of CYP46A1 directs altered cholesterol homeostasis and opens therapeutic opportunities for glioblastoma

2019 ◽  
Vol 21 (Supplement_3) ◽  
pp. iii12-iii12
Author(s):  
M Han ◽  
S Wang ◽  
X Li ◽  
J Wang ◽  
R Bjerkvig
Keyword(s):  
Tumour Growth ◽  
Cholesterol Metabolism ◽  
Ectopic Expression ◽  
Xenograft Model ◽  
Cholesterol Homeostasis ◽  
Normal Brain ◽  
Genomic Databases ◽  
Orthotopic Xenograft Model

Abstract BACKGROUND Dysregulated cholesterol metabolism is a hallmark of many cancers, including glioblastoma (GBM), but its role in disease progression is not well understood. Here, we identified cholesterol 24-hydroxylase (CYP46A1), a brain-specific enzyme responsible for elimination of cholesterol through conversion of cholesterol to 24(S)-hydroxycholesterol (24OHC), as one of the most dramatically dysregulated cholesterol metabolism genes in GBM. MATERIAL AND METHODS Molecular and clinical data was obtained from publicly genomic databases. Immunohistochemistry was applied to assess protein levels of CYP46A1 in primary GBM samples. Lentiviral constructs expressing CYP46A1 were transduced into LN229, LN18 and primary GBM GSCs for functional assays carried out in vitro and in vivo in an orthotopic xenograft model. RNA-seq was performed to identify downstream targets of 24OHC. RESULTS CYP46A1 was significantly decreased in GBM samples compared to normal brain tissue. Reduced CYP46A1 expression was associated with increasing tumour grade and poor prognosis in GBM patients. Ectopic expression of CYP46A1 suppressed cell proliferation and in vivo tumour growth by increasing 24OHC levels. Treatment of GBM cells with 24OHC suppressed tumour growth through regulation of LXR and SREBP signalling. Efavirenz (EFV), an activator of CYP46A1 with BBB penetration, inhibited GBM growth in vivo. CONCLUSION Our findings demonstrate that CYP46A1 is a critical regulator of cellular cholesterol in GBM and that the CYP46A1/24OHC axis is a potential therapeutic target.

scholarly journals FSMP-11. TARGETING CHOLESTEROL HOMEOSTASIS DYSREGULATION FOR THE TREATMENT OF GLIOBLASTOMA

2020 ◽  
Vol 3 (Supplement_1) ◽  
pp. i18-i18
Author(s):  
Mingzhi Han
Keyword(s):  
Tumour Growth ◽  
Cholesterol Metabolism ◽  
Ectopic Expression ◽  
Cholesterol Homeostasis ◽  
Normal Brain ◽  
Rna Seq ◽  
Specific Enzyme ◽  
Normal Brain Tissue ◽  
Potential Therapeutic Target

Abstract Dysregulated cholesterol metabolism is a hallmark of many cancers, including glioblastoma (GBM), but its role in disease progression is not well understood. Here, we identified cholesterol 24-hydroxylase (CYP46A1), a brain-specific enzyme responsible for elimination of cholesterol through conversion of cholesterol to 24(S)-hydroxycholesterol (24OHC), as one of the most dramatically dysregulated cholesterol metabolism genes in GBM. CYP46A1 was significantly decreased in GBM samples compared to normal brain tissue. In gliomas, a reduction in CYP46A1 expression was associated with increasing tumour grade and poor prognosis. Functionally, ectopic expression of CYP46A1 suppressed cell proliferation and in vivo tumour growth by increasing 24OHC levels. RNA-seq revealed that treatment of GBM cells with 24OHC suppressed tumour growth through regulation of LXR and SREBP signaling. Efavirenz (EFV), an activator of CYP46A1 that is known to penetrate the blood-brain barrier (BBB), inhibited GBM growth in vivo. Our findings demonstrate that CYP46A1 is a critical regulator of cellular cholesterol in GBM and that the CYP46A1/24OHC axis is a potential therapeutic target.

scholarly journals Ribosomal Protein S27-Like is overexpressed in glioma cells and inhibition of RPS27L expression suspends the tumorigenesis

2020 ◽  
Author(s):  
Zhongzheng Sun ◽  
Hao Xue ◽  
Yan Wei ◽  
Shaobo Wang ◽  
Jianye Xu ◽  
...  
Keyword(s):  
Ribosomal Protein ◽  
Xenograft Model ◽  
Glioma Cells ◽  
Tumor Grade ◽  
Migration And Invasion ◽  
Normal Brain ◽  
Orthotopic Xenograft Model ◽  
High Expression Group

Abstract Background: Ribosomal Protein S27-Like is an evolutionarily conserved ribosomal protein and the role of RPS27L influencing the malignance of several cancers has been reported. However, its effects on glioma were still unknown. This investigation aims to characterize the clinical significance and the biological functions of RPS27L in gliomas.Methods: TCGA databases were explored to analyze the correlation between RPS27L expression and the clinical characteristics of glioma patients. Immunohistochemical staining was performed on glioma cases and normal brain tissues. The function of RPS27L in glioma was further explored using U87MG and A172 cell lines and a orthotopic xenograft model of nude mice.Results: Data obtained from TCGA database showed higher expression of RPS27L in glioma than normal, and the overall survival was lower in the high expression group. Immunohistochemistry showed the expression levels of RPS27L were increased with the tumor grade rising in gliomas. Functional assays showed knockdown of RPS27L inhibited proliferation, cell cycle transition, migration and invasion, while promoted apoptosis. Data of western blot indicated that knockdown of RPS27L increased the level of p21，Bax and Cleaved Caspase-3 while decreased the level of CDK4, cyclinD1, cyclinE1, Bcl-2 and MMP2, MMP9 in glioma cells. In vivo, the growth of orthotopic glioma xenografts was suppressed by expression of RPS27L shRNA, and the tumors with RPS27L shRNA showed less aggressiveness and reduced expression of Ki67, Bcl-2 and MMP2. Conclusions: RPS27L is overexpressed in glioma cells. Knockdown of RPS27L could inhibit the proliferation, migration and invasion while promote apoptosis of glioma cells in vitro and in vivo. RPS27L might be a potential prognostic biomarker and possible target for future therapy in glioma.

scholarly journals Ribosomal Protein S27-Like is overexpressed in glioma cells and inhibition of RPS27L expression suspends the tumorigenesis

2020 ◽  
Author(s):  
Zhongzheng Sun ◽  
Hao Xue ◽  
Yan Wei ◽  
Shaobo Wang ◽  
Jianye Xu ◽  
...  
Keyword(s):  
Ribosomal Protein ◽  
Xenograft Model ◽  
Glioma Cells ◽  
Tumor Grade ◽  
Migration And Invasion ◽  
Normal Brain ◽  
Orthotopic Xenograft Model ◽  
High Expression Group

Abstract Background: Ribosomal Protein S27-Like is an evolutionarily conserved ribosomal protein and the role of RPS27L influencing the malignance of several cancers has been reported. However, its effects on glioma were still unknown. This investigation aims to characterize the clinical significance and the biological functions of RPS27L in gliomas.Methods: TCGA databases were explored to analyze the correlation between RPS27L expression and the clinical characteristics of glioma patients. Immunohistochemical staining was performed on glioma cases and normal brain tissues. The function of RPS27L in glioma was further explored using U87MG and A172 cell lines and a orthotopic xenograft model of nude mice.Results: Data obtained from TCGA database showed higher expression of RPS27L in glioma than normal, and the overall survival was lower in the high expression group. Immunohistochemistry showed the expression levels of RPS27L were increased with the tumor grade rising in gliomas. Functional assays showed knockdown of RPS27L inhibited proliferation, cell cycle transition, migration and invasion, while promoted apoptosis. Data of western blot indicated that knockdown of RPS27L increased the level of p21，Bax and Cleaved Caspase-3 while decreased the level of CDK4, cyclinD1, cyclinE1, Bcl-2 and MMP2, MMP9 in glioma cells. In vivo, the growth of orthotopic glioma xenografts was suppressed by expression of RPS27L shRNA, and the tumors with RPS27L shRNA showed less aggressiveness and reduced expression of Ki67, Bcl-2 and MMP2. Conclusions: RPS27L is overexpressed in glioma cells. Knockdown of RPS27L could inhibit the proliferation, migration and invasion while promote apoptosis of glioma cells in vitro and in vivo. RPS27L might be a potential prognostic biomarker and possible target for future therapy in glioma.

scholarly journals miR551b Regulates Colorectal Cancer Progression by Targeting the ZEB1 Signaling Axis

Cancers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 735 ◽  
Author(s):  
Kwang Seock Kim ◽  
Dongjun Jeong ◽  
Ita Novita Sari ◽  
Yoseph Toni Wijaya ◽  
Nayoung Jun ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cell Lines ◽  
Cancer Progression ◽  
Epithelial Mesenchymal Transition ◽  
Ectopic Expression ◽  
Xenograft Model ◽  
Mesenchymal Transition ◽  
Normal Tissues

Our current understanding of the role of microRNA 551b (miR551b) in the progression of colorectal cancer (CRC) remains limited. Here, studies using both ectopic expression of miR551b and miR551b mimics revealed that miR551b exerts a tumor suppressive effect in CRC cells. Specifically, miR551b was significantly downregulated in both patient-derived CRC tissues and CRC cell lines compared to normal tissues and non-cancer cell lines. Also, miR551b significantly inhibited the motility of CRC cells in vitro, including migration, invasion, and wound healing rates, but did not affect cell proliferation. Mechanistically, miR551b targets and inhibits the expression of ZEB1 (Zinc finger E-box-binding homeobox 1), resulting in the dysregulation of EMT (epithelial-mesenchymal transition) signatures. More importantly, miR551b overexpression was found to reduce the tumor size in a xenograft model of CRC cells in vivo. Furthermore, bioinformatic analyses showed that miR551b expression levels were markedly downregulated in the advanced-stage CRC tissues compared to normal tissues, and ZEB1 was associated with the disease progression in CRC patients. Our findings indicated that miR551b could serve as a potential diagnostic biomarker and could be utilized to improve the therapeutic outcomes of CRC patients.

scholarly journals Dkk-3, a Secreted Wnt Antagonist, Suppresses Tumorigenic Potential and Pulmonary Metastasis in Osteosarcoma

Sarcoma ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Carol H. Lin ◽  
Yi Guo ◽  
Samia Ghaffar ◽  
Peter McQueen ◽  
Jonathan Pourmorady ◽  
...  
Keyword(s):  
Cell Lines ◽  
Negative Impact ◽  
Xenograft Model ◽  
Pulmonary Nodules ◽  
Cellular Motility ◽  
Control Vector ◽  
Orthotopic Xenograft Model ◽  
Tumorigenic Potential

Osteosarcoma (OS) is the most common primary bone malignancy with a high propensity for local invasion and distant metastasis. Despite current multidisciplinary treatments, there has not been a drastic change in overall prognosis within the past 2 decades. Dickkopf-3 protein (Dkk-3/REIC) has been known to inhibit canonical Wnt/β-catenin pathway, and its expression has been shown to be downregulated in OS cell lines. Usingin vivoandin vitrostudies, we demonstrated that Dkk-3-transfected 143B cells inhibited tumorigenesis and metastasis in an orthotopic xenograft model of OS. Inoculation of Dkk-3-transfected 143B cell lines into nude mice showed significant decreased tumor growth and less metastatic pulmonary nodules (88.7%) compared to the control vector.In vitroexperiments examining cellular motility and viability demonstrated less anchorage-independent growth and decreased cellular motility for Dkk-3-transfected 143B and SaOS2 cell lines compared to the control vector. Downstream expressions of Met, MAPK, ALK, and S1004A were also downregulated in Dkk-3-transfected SaOS2 cells, suggesting the ability of Dkk-3 to inhibit tumorigenic potential of OS. Together, these data suggest that Dkk-3 has a negative impact on the progression of osteosarcoma. Reexpressing Dkk-3 in Dkk-3-deficient OS tumors may prove to be of benefit as a preventive or therapeutic strategy.

scholarly journals Cholesterol Metabolic Reprogramming in Cancer and Its Pharmacological Modulation as Therapeutic Strategy

2021 ◽  
Vol 11 ◽  
Author(s):  
Isabella Giacomini ◽  
Federico Gianfanti ◽  
Maria Andrea Desbats ◽  
Genny Orso ◽  
Massimiliano Berretta ◽  
...  
Keyword(s):  
De Novo ◽  
Mevalonate Pathway ◽  
Cholesterol Metabolism ◽  
Tumor Development ◽  
Cholesterol Homeostasis ◽  
Metabolic Reprogramming ◽  
Protein Prenylation ◽  
Pharmacological Targets

Cholesterol is a ubiquitous sterol with many biological functions, which are crucial for proper cellular signaling and physiology. Indeed, cholesterol is essential in maintaining membrane physical properties, while its metabolism is involved in bile acid production and steroid hormone biosynthesis. Additionally, isoprenoids metabolites of the mevalonate pathway support protein-prenylation and dolichol, ubiquinone and the heme a biosynthesis. Cancer cells rely on cholesterol to satisfy their increased nutrient demands and to support their uncontrolled growth, thus promoting tumor development and progression. Indeed, transformed cells reprogram cholesterol metabolism either by increasing its uptake and de novo biosynthesis, or deregulating the efflux. Alternatively, tumor can efficiently accumulate cholesterol into lipid droplets and deeply modify the activity of key cholesterol homeostasis regulators. In light of these considerations, altered pathways of cholesterol metabolism might represent intriguing pharmacological targets for the development of exploitable strategies in the context of cancer therapy. Thus, this work aims to discuss the emerging evidence of in vitro and in vivo studies, as well as clinical trials, on the role of cholesterol pathways in the treatment of cancer, starting from already available cholesterol-lowering drugs (statins or fibrates), and moving towards novel potential pharmacological inhibitors or selective target modulators.

scholarly journals EXTH-19. EVALUATING THE ANTI-TUMOR EFFECT OF A NOVEL THERAPEUTIC AGENT, MAGMAS INHIBITOR, IN MALIGNANT GLIOMA

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii90-ii91
Author(s):  
Kaijun Di ◽  
Senjie Du ◽  
Javier Lepe ◽  
Nitesh Nandwana ◽  
Bhaskar Das ◽  
...  
Keyword(s):  
Cell Biology ◽  
Xenograft Model ◽  
Nuclear Gene ◽  
In Vitro Study ◽  
Maximum Tolerated Dose ◽  
Treatment Modalities ◽  
Multiple Treatment ◽  
Orthotopic Xenograft Model

Abstract BACKGROUNDS Glioblastoma (GBM) is an aggressive infiltrative brain tumor, and has an extremely poor prognosis despite the use of multiple treatment modalities, including surgery, radiation, and chemotherapy. Meanwhile, mitochondrial changes represent a significant part of cancer cell biology since cancer cells must survive and adapt to challenging microenvironments, specifically in conditions where tumor growth makes oxygen and glucose scarce. As GBM is characterized by extensive hypoxia-induced phenotypic changes such as abnormal vascular proliferation and necrosis, regulation of mitochondrial function could be a novel approach for treating GBM that currently lacks effective therapies. Magmas (mitochondria-associated protein involved in granulocyte-macrophage colony-stimulating factor signal transduction) is a nuclear gene that encodes for the mitochondrial import inner membrane translocase subunit Tim16. We previously demonstrated that a novel Magmas inhibitor, BT#9, significantly exerted anti-tumor effect in glioma in vitro, and may cross the blood brain barrier in vivo, indicating that Magmas inhibitor may be a new chemotherapeutic agent for the treatment of GBM. METHODS In this study, the antitumor effect of Magmas inhibitor BT#9 was tested in an orthotopic xenograft model of human GBM. The molecular mechanism of BT#9 was investigated using glioma cell lines. RESULTS The mice were tolerated to BT#9, and there was no statistical difference in the weight of animals between the control and MTD (Maximum-tolerated Dose, 50mg/kg) groups. The immunocompromised mice, intracranially implanted with human D-54 GBM xenografts, survived significantly longer than the controls (P< 0.5) when treated with BT#9 at MTD. In vitro study showed that the MAP kinase pathways are involved in BT#9-induced tumor suppression. DISCUSSION This is the first study on the role of Magmas in glioma in vivo. Our findings suggested that Magmas plays a key role in glioma survival and targeting Magmas by Magmas inhibitor has the potential to become a therapeutic strategy in glioma patients.

STEM-15. SerpinB3 DRIVES CANCER STEM CELL SURVIVAL IN GLIOBLASTOMA

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi24-vi24
Author(s):  
Adam Lauko ◽  
Soumya M Turaga ◽  
Josephine Volovetz ◽  
Defne Bayik ◽  
Shideng Bao ◽  
...  
Keyword(s):  
Cell Death ◽  
Protease Inhibitor ◽  
Cysteine Protease ◽  
Xenograft Model ◽  
Standard Of Care ◽  
Therapeutic Interventions ◽  
Cysteine Protease Inhibitor ◽  
Orthotopic Xenograft Model

Abstract Despite therapeutic interventions for glioblastoma (GBM), self-renewing, therapy-resistant populations of cells referred to as cancer stem cells (CSCs) drive recurrence. Previously, we identified the unique expression of junctional adhesion molecule-A (JAM-A) on CSCs and demonstrated that JAM-A is both necessary and sufficient for self-renewal and tumor growth. Moreover, we determined that JAM-A signals via Akt in GBM CSCs to sustain pluripotency transcription factor activity; however, the entire signaling network has yet to be fully elucidated. To further delineate this pathway, we immunoprecipitated JAM-A from patient-derived GBM CSCs and performed mass spectrometry to determine JAM-A binding proteins. This led to the identification of the cysteine protease inhibitor SerpinB3 as a putative JAM-A binding partner. Using in vitro CSC functional assays, we show that SerpinB3 is necessary for CSC maintenance and survival. In an in vivo orthotopic xenograft model, knockdown of SerpinB3 extended survival. Mechanistically, knockdown of SerpinB3 led to decreased expression of TGF-β, Myc, WNT, and Notch signaling, known regulators of the CSC state. Additionally, knockdown of SerpinB3 increases susceptibility to radiation therapy. SerpinB3 is essential for buffering cells against cathepsin-mediated cell death, and we found that elevated lysosomal membrane permeability after radiation leads to cathepsin release into the cytoplasm. As a result, SerpinB3 knockdown cells have a diminished capacity to inhibit cathepsin-driven cell death after radiation. The addition of the cathepsin inhibitor E64D partially rescues the SerpinB3 knockdown, however, SerpinB3 mutants that are unable to inhibit cathepsins fail to do the same. Taken together, our findings, identify a novel GBM CSC-specific survival mechanism involving a previously uninvestigated cysteine protease inhibitor, SerpinB3, and provide a potential target to increase the efficacy of standard of care GBM therapies against therapy-resistant CSCs.

scholarly journals Metabolism of Reactive Oxygen Species in Osteosarcoma and Potential Treatment Applications

Cells ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 87 ◽  
Author(s):  
Wei Sun ◽  
Bing Wang ◽  
Xing-Long Qu ◽  
Bi-Qiang Zheng ◽  
Wen-Ding Huang ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Tumour Growth ◽  
Xenograft Model ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Mg63 Cells ◽  
Ros Accumulation ◽  
Ros Formation

Background: The present study was designed to explore the underlying role of hypoxia-inducible factor 1α (HIF-1α) in reactive oxygen species (ROS) formation and apoptosis in osteosarcoma (OS) cells induced by hypoxia. Methods: In OS cells, ROS accumulated and apoptosis increased within 24 h after exposure to low HIF-1α expression levels. A co-expression analysis showed that HIF was positively correlated with Forkhead box class O1 (FoxO1) expression and negatively correlated with CYP-related genes from the National Center for Biotechnology Information’s Gene Expression Omnibus (NCBI GEO) datasets. Hypoxia also considerably increased HIF-1α and FoxO1 expression. Moreover, the promoter region of FoxO1 was directly regulated by HIF-1α. We inhibited HIF-1α via siRNA and found that the ROS accumulation and apoptosis induced by hypoxia in OS cells decreased. In this study, a murine xenograft model of BALB-c nude mice was adopted to test tumour growth and measure the efficacy of 2-ME + As2O3 treatment. Results: Ad interim knockdown of HIF-1α also inhibited manganese-dependent superoxide dismutase (MnSOD), catalase and sestrin 3 (Sesn3) expression in OS cells. Furthermore, hypoxia-induced ROS formation and apoptosis in OS cells were associated with CYP450 protein interference and were ablated by HIF-1α silencing via siRNA. Conclusions: Our data reveal that HIF-1α inhibits ROS accumulation by directly regulating FoxO1 in OS cells, which induces MnSOD, catalase and Sesn3 interference, thus resulting in anti-oxidation effects. The combination of an HIF-1α inhibitor (2-mercaptoethanol,2-ME) and ROS inducer (arsenous oxide, As2O3) can prohibit proliferation and migration and promote apoptosis in MG63 cells in vitro while inhibiting tumour growth in vivo.

scholarly journals Macrophage-derived cholesterol contributes to therapeutic resistance in prostate cancer

2021 ◽  
Author(s):  
Asmaa El-Kenawi ◽  
William Dominguez-Viqueira ◽  
Min Liu ◽  
Shivanshu Awasthi ◽  
Aysenur Keske ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cancer Progression ◽  
Nuclear Translocation ◽  
Cholesterol Metabolism ◽  
Therapeutic Potential ◽  
Cholesterol Homeostasis ◽  
Castration Resistant Prostate Cancer ◽  
Macrophage Depletion

Tumor-associated macrophages are key immune cells associated with cancer progression. Here we sought to determine the role of macrophages in castration-resistant prostate cancer (CRPC) using a syngeneic model that reflected the mutational landscape of the disease. A transcriptomic analysis of CRPC tumors following macrophage depletion revealed lower molecular signatures for steroid and bile acid synthesis, indicating potential perturbation of cholesterol metabolism. Since cholesterol is the precursor of the five major classes of steroid hormones, we reasoned that macrophages were regulating androgen biosynthesis within the prostate tumor microenvironment. Indeed, macrophage depletion reduced the levels of androgens within prostate tumors and restricted androgen receptor (AR) nuclear localization in vitro and in vivo. Macrophages were cholesterol rich and had the ability to transfer cholesterol to tumor cells in vitro, and AR nuclear translocation was inhibited by activation of Liver X Receptor (LXR)-β, the master regulator of cholesterol homeostasis. Finally, combining macrophage depletion with androgen deprivation therapy increased survival, supporting the therapeutic potential of targeting macrophages in CRPC.

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