scholarly journals Glioblastoma utilizes fatty acids and ketone bodies for growth allowing progression during ketogenic diet therapy

2019 ◽  
Author(s):  
Jantzen Sperry ◽  
Michael C. Condro ◽  
Lea Guo ◽  
Daniel Braas ◽  
Nathan Vanderveer-Harris ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Ketogenic Diet ◽  
Ketone Bodies ◽  
Aerobic Glycolysis ◽  
Diet Therapy ◽  
Acid Oxidation ◽  
Reduce Tumor Growth

SummaryGlioblastoma (GBM) metabolism has traditionally been characterized by a primary dependence on aerobic glycolysis, prompting the use of the ketogenic diet (KD) as a potential therapy. In this study we evaluated the effectiveness of the KD in GBM and assessed the role of fatty acid oxidation (FAO) in promoting GBM propagation. In vitro assays revealed FA utilization throughout the GBM metabolome, and growth inhibition in nearly every cell line in a broad spectrum of patient-derived glioma cells treated with FAO inhibitors. In vivo assessments revealed that knockdown of carnitine palmitoyltransferase 1A (CPT1A), the rate limiting enzyme for FAO, reduced the rate of tumor growth and increased survival. However, the unrestricted ketogenic diet did not reduce tumor growth, and for some models significantly reduced survival. Altogether, these data highlight important roles for FA and ketone body metabolism that could serve to improve targeted therapies in GBM.

scholarly journals Down-regulation of the mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase gene by insulin: the role of the forkhead transcription factor FKHRL1

2002 ◽  
Vol 366 (1) ◽  
pp. 289-297 ◽  
Author(s):  
Alícia NADAL ◽  
Pedro F. MARRERO ◽  
Diego HARO
Keyword(s):  
Ketone Bodies ◽  
Control Site ◽  
Luciferase Reporter ◽  
Acid Oxidation ◽  
Transcription Start ◽  
Forkhead Transcription Factor ◽  
The Brain

Normal physiological responses to carbohydrate shortages cause the liver to increase the production of ketone bodies from the acetyl-CoA generated from fatty acid oxidation. This allows the use of ketone bodies for energy, thereby preserving the limited glucose for use by the brain. This adaptative response is switched off by insulin rapidly inhibiting the expression of the mitochondrial 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase (HMGCS2) gene, which is a key control site of ketogenesis. We decided to investigate the molecular mechanism of this inhibition. In the present study, we show that FKHRL1, a member of the forkhead in rhabdosarcoma (FKHR) subclass of the Fox family of transcription factors, stimulates transcription from transfected 3-hydroxy-3-methylglutaryl-CoA synthase promoter-luciferase reporter constructs, and that this stimulation is repressed by insulin. An FKHRL1-responsive sequence AAAAATA, located 211bp upstream of the HMGCS2 gene transcription start site, was identified by deletion analysis. It binds FKHRL1 in vivo and in vitro and confers FKHRL1 responsiveness on homologous and heterologous promoters. If it is mutated, it partially blocks the effect of insulin in HepG2 cells, both in the absence and presence of overexpressed FKHRL1. These results suggest that FKHRL1 contributes to the regulation of HMGCS2 gene expression by insulin.

scholarly journals Low ketolytic enzyme levels in tumors predict ketogenic diet responses in cancer cell lines in vitro and in vivo

2018 ◽  
Vol 59 (4) ◽  
pp. 625-634 ◽  
Author(s):  
Jie Zhang ◽  
Ping-Ping Jia ◽  
Qing-Le Liu ◽  
Ming-Hua Cong ◽  
Yun Gao ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Cell Lines ◽  
Ketogenic Diet ◽  
Cancer Cell ◽  
Hela Cells ◽  
Ketone Bodies ◽  
Cancer Cell Lines ◽  
Coa Transferase

The ketogenic diet (KD) is a high-fat, very-low-carbohydrate diet that triggers a fasting state by decreasing glucose and increasing ketone bodies, such as β-hydroxybutyrate (βHB). In experimental models and clinical trials, the KD has shown anti-tumor effects, possibly by reducing energy supplies to cells, which damage the tumor microenvironment and inhibit tumor growth. Here, we determined expression levels of genes encoding the ketolytic enzymes 3-hydroxybutyrate dehydrogenase 1 (BDH1) and succinyl-CoA: 3-oxoacid CoA transferase 1 (OXCT1) in 33 human cancer cell lines. We then selected two representative lines, HeLa and PANC-1, for in vivo examination of KD sensitivity in tumors with high or low expression, respectively, of these two enzymes. In mice with HeLa xenografts, the KD increased tumor growth and mouse survival decreased, possibly because these tumors actively consumed ketone bodies as an energy source. Conversely, the KD significantly inhibited growth of PANC-1 xenograft tumors. βHB added to each cell culture significantly increased proliferation of HeLa cells, but not PANCI-1 cells. Downregulation of both BDH1 and OXCT1 rendered HeLa cells sensitive to the KD in vitro and in vivo. Tumors with low ketolytic enzyme expression may be unable to metabolize ketone bodies, thus predicting a better response to KD therapy.

scholarly journals Blocking the GITR-GITRL pathway to overcome resistance to therapy in sarcomatoid malignant pleural mesothelioma

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Meilin Chan ◽  
Licun Wu ◽  
Zhihong Yun ◽  
Trevor D. McKee ◽  
Michael Cabanero ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Malignant Pleural Mesothelioma ◽  
Neutralizing Antibodies ◽  
Pleural Mesothelioma ◽  
Spheroid Formation ◽  
Resistance To Therapy ◽  
Sarcomatoid Mesothelioma

AbstractMalignant pleural mesothelioma (MPM) is an aggressive neoplasm originating from the pleura. Non-epithelioid (biphasic and sarcomatoid) MPM are particularly resistant to therapy. We investigated the role of the GITR-GITRL pathway in mediating the resistance to therapy. We found that GITR and GITRL expressions were higher in the sarcomatoid cell line (CRL5946) than in non-sarcomatoid cell lines (CRL5915 and CRL5820), and that cisplatin and Cs-137 irradiation increased GITR and GITRL expressions on tumor cells. Transcriptome analysis demonstrated that the GITR-GITRL pathway was promoting tumor growth and inhibiting cell apoptosis. Furthermore, GITR+ and GITRL+ cells demonstrated increased spheroid formation in vitro and in vivo. Using patient derived xenografts (PDXs), we demonstrated that anti-GITR neutralizing antibodies attenuated tumor growth in sarcomatoid PDX mice. Tumor immunostaining demonstrated higher levels of GITR and GITRL expressions in non-epithelioid compared to epithelioid tumors. Among 73 patients uniformly treated with accelerated radiation therapy followed by surgery, the intensity of GITR expression after radiation negatively correlated with survival in non-epithelioid MPM patients. In conclusion, the GITR-GITRL pathway is an important mechanism of autocrine proliferation in sarcomatoid mesothelioma, associated with tumor stemness and resistance to therapy. Blocking the GITR-GITRL pathway could be a new therapeutic target for non-epithelioid mesothelioma.

scholarly journals KLF7/VPS35 axis contributes to hepatocellular carcinoma progression through CCDC85C-activated β-catenin pathway

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yarong Guo ◽  
Bao Chai ◽  
Junmei Jia ◽  
Mudan Yang ◽  
Yanjun Li ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Proliferation ◽  
Tumor Growth ◽  
Luciferase Reporter ◽  
Aberrant Expression ◽  
Proliferation And Invasion ◽  
Hcc Cells

Abstract Objective Dysregulation of KLF7 participates in the development of various cancers, but it is unclear whether there is a link between HCC and aberrant expression of KLF7. The aim of this study was to investigate the role of KLF7 in proliferation and migration of hepatocellular carcinoma (HCC) cells. Methods CCK8, colony growth, transwell, cell cycle analysis and apoptosis detection were performed to explore the effect of KLF7, VPS35 and Ccdc85c on cell function in vitro. Xenografted tumor growth was used to assess in vivo role of KLF7. Chip-qPCR and luciferase reporter assays were applied to check whether KLF7 regulated VPS35 at transcriptional manner. Co-IP assay was performed to detect the interaction between VPS35 and Ccdc85c. Immunohistochemical staining and qRT-PCR analysis were performed in human HCC sampels to study the clinical significance of KLF7, VPS35 and β-catenin. Results Firstly, KLF7 was highly expressed in human HCC samples and correlated with patients’ differentiation and metastasis status. KLF7 overexpression contributed to cell proliferation and invasion of HCC cells in vitro and in vivo. KLF7 transcriptional activation of VPS35 was necessary for HCC tumor growth and metastasis. Further, co-IP studies revealed that VPS35 could interact with Ccdc85c in HCC cells. Rescue assay confirmed that overexpression of VPS35 and knockdown of Ccdc85c abolished the VPS35-medicated promotion effect on cell proliferation and invasion. Finally, KLF7/VPS35 axis regulated Ccdc85c, which involved in activation of β-catenin signaling pathway, confirmed using β-catenin inhibitor, GK974. Functional studies suggested that downregulation of Ccdc85c partly reversed the capacity of cell proliferation and invasion in HCC cells, which was regulated by VPS35 upregulation. Lastly, there was a positive correlation among KLF7, VPS35 and active-β-catenin in human HCC patients. Conclusion We demonstrated that KLF7/VPS35 axis promoted HCC cell progression by activating Ccdc85c-medicated β-catenin pathway. Targeting this signal axis might be a potential treatment strategy for HCC.

scholarly journals Hypermethylation of DHRS3 as a Novel Tumor Suppressor Involved in Tumor Growth and Prognosis in Gastric Cancer

2021 ◽  
Vol 9 ◽  
Author(s):  
Sha Sumei ◽  
Kong Xiangyun ◽  
Chen Fenrong ◽  
Sun Xueguang ◽  
Hu Sijun ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Tumor Suppressor ◽  
Tumor Growth ◽  
Human Cancer ◽  
Methylation Status ◽  
Ectopic Expression ◽  
Survival Times

Background/AimsThe role of DHRS3 in human cancer remains unclear. Our study explored the role of DHRS3 in gastric cancer (GC) and its clinicopathological significance and associated mechanisms.MaterialsBisulfite-assisted genomic sequencing PCR and a Mass-Array system were used to evaluate and quantify the methylation levels of the promoter. The expression levels and biological function of DHRS3 was examined by both in vitro and in vivo assays. A two-way hierarchical cluster analysis was used to classify the methylation profiles, and the correlation between the methylation status of the DHRS3 promoter and the clinicopathological characteristics of GC were then assessed.ResultsThe DHRS3 promoter was hypermethylated in GC samples, while the mRNA and protein levels of DHRS3 were significantly downregulated. Ectopic expression of DHRS3 in GC cells inhibited cell proliferation and migration in vitro, decreased tumor growth in vivo. DHRS3 methylation was correlated with histological type and poor differentiation of tumors. GC patients with high degrees of CpG 9.10 methylation had shorter survival times than those with lower methylation.ConclusionDHRS3 was hypermethylated and downregulated in GC patients. Reduced expression of DHRS3 is implicated in gastric carcinogenesis, which suggests DHRS3 is a tumor suppressor.

scholarly journals The critical immunosuppressive effect of MDSC-derived exosomes in the tumor microenvironment

2020 ◽  
Author(s):  
Mohammad H. Rashid ◽  
Thaiz F. Borin ◽  
Roxan Ara ◽  
Raziye Piranlioglu ◽  
Bhagelu R. Achyut ◽  
...  
Keyword(s):  
T Cells ◽  
Tumor Microenvironment ◽  
Tumor Growth ◽  
Cd8 T Cells ◽  
Suppressor Cells ◽  
Cell Types ◽  
Biological Macromolecules

AbstractMyeloid-derived suppressor cells (MDSCs) are an indispensable component of the tumor microenvironment (TME), and our perception regarding the role of MDSCs in tumor promotion is attaining extra layer of intricacy in every study. In conjunction with MDSC’s immunosuppressive and anti-tumor immunity, they candidly facilitate tumor growth, differentiation, and metastasis in several ways that yet to be explored. Alike any other cell types, MDSCs also release a tremendous amount of exosomes or nanovesicles of endosomal origin and partake in intercellular communications by dispatching biological macromolecules. There has not been any experimental study done to characterize the role of MDSCs derived exosomes (MDSC exo) in the modulation of TME. In this study, we isolated MDSC exo and demonstrated that they carry a significant amount of proteins that play an indispensable role in tumor growth, invasion, angiogenesis, and immunomodulation. We observed higher yield and more substantial immunosuppressive potential of exosomes isolated from MDSCs in the primary tumor area than those are in the spleen or bone marrow. Our in vitro data suggest that MDSC exo are capable of hyper activating or exhausting CD8 T-cells and induce reactive oxygen species production that elicits activation-induced cell death. We confirmed the depletion of CD8 T-cells in vivo by treating the mice with MDSC exo. We also observed a reduction in pro-inflammatory M1-macrophages in the spleen of those animals. Our results indicate that immunosuppressive and tumor-promoting functions of MDSC are also implemented by MDSC-derived exosomes which would open up a new avenue of MDSC research and MDSC-targeted therapy.

scholarly journals BCAT1 Activates PI3K/AKT/mTOR Pathway and Contributes to the Angiogenesis and Tumorigenicity of Gastric Cancer

2021 ◽  
Vol 9 ◽  
Author(s):  
Xiong Shu ◽  
Pan-Pan Zhan ◽  
Li-Xin Sun ◽  
Long Yu ◽  
Jun Liu ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Tumor Growth ◽  
Western Blotting ◽  
Mtor Pathway ◽  
Clinical Samples ◽  
Xenograft Models ◽  
Cell Phenotypes

BackgroundFocusing on antiangiogenesis may provide promising choices for treatment of gastric cancer (GC). This study aimed to investigate the mechanistic role of BCAT1 in the pathogenesis of GC, particularly in angiogenesis.MethodsBioinformatics and clinical samples analysis were used to investigate the expression and potential mechanism of BCAT1 in GC. BGC823 cells with BCAT1 overexpression or silencing were induced by lentiviral transduction. Cell phenotypes and angiogenesis were evaluated. The relevant proteins were quantized by Western blotting, immunohistochemistry, or immunofluorescence. Xenograft models were constructed to confirm the role of BCAT1 in vivo.ResultsBCAT1 was overexpressed in GC patients and associated with lower survival. BCAT1 expression was correlated with proliferation-, invasion-, or angiogenesis-related markers expression and pathways. Silencing BCAT1 expression suppressed cell viability, colony formation, cycle progression, invasion, and angiogenesis of BGC823 cells, as well as the tumor growth of xenograft models, whereas overexpressing BCAT1 had the opposite results both in vitro and in vivo. Bioinformatics analysis and Western blotting demonstrated that BCAT1 activated the PI3K/AKT/mTOR pathway. The addition of LY294002 reversed the tumor growth induced by BCAT1 overexpression, further verifying this mechanism.ConclusionBCAT1 might act as an oncogene by facilitating proliferation, invasion, and angiogenesis through activation of the PI3K/AKT/mTOR pathway. This finding could aid the optimization of antiangiogenesis strategies.

scholarly journals Tissue-specific characterization of mitochondrial branched-chain keto acid oxidation using a multiplexed assay platform

2019 ◽  
Vol 476 (10) ◽  
pp. 1521-1537 ◽  
Author(s):  
Emma J. Goldberg ◽  
Katherine A. Buddo ◽  
Kelsey L. McLaughlin ◽  
Regina F. Fernandez ◽  
Andrea S. Pereyra ◽  
...  
Keyword(s):  
Acid Oxidation ◽  
Valuable Insight ◽  
Keto Acid ◽  
Isolated Mitochondria ◽  
Mouse Tissues ◽  
Branched Chain

Abstract Alterations to branched-chain keto acid (BCKA) oxidation have been implicated in a wide variety of human diseases, ranging from diabetes to cancer. Although global shifts in BCKA metabolism—evident by gene transcription, metabolite profiling, and in vivo flux analyses have been documented across various pathological conditions, the underlying biochemical mechanism(s) within the mitochondrion remain largely unknown. In vitro experiments using isolated mitochondria represent a powerful biochemical tool for elucidating the role of the mitochondrion in driving disease. Such analyses have routinely been utilized across disciplines to shed valuable insight into mitochondrial-linked pathologies. That said, few studies have attempted to model in vitro BCKA oxidation in isolated organelles. The impetus for the present study stemmed from the knowledge that complete oxidation of each of the three BCKAs involves a reaction dependent upon bicarbonate and ATP, both of which are not typically included in respiration experiments. Based on this, it was hypothesized that the inclusion of exogenous bicarbonate and stimulation of respiration using physiological shifts in ATP-free energy, rather than excess ADP, would allow for maximal BCKA-supported respiratory flux in isolated mitochondria. This hypothesis was confirmed in mitochondria from several mouse tissues, including heart, liver and skeletal muscle. What follows is a thorough characterization and validation of a novel biochemical tool for investigating BCKA metabolism in isolated mitochondria.

The role of ZNF395 in renal cell carcinoma proliferation, migration, and invasion.

2016 ◽  
Vol 34 (2_suppl) ◽  
pp. 592-592 ◽  
Author(s):  
Chen Zhao ◽  
Christopher G. Wood ◽  
Jose A. Karam ◽  
Tapati Maity ◽  
Lei Wang
Keyword(s):  
Renal Cell Carcinoma ◽  
Tumor Growth ◽  
Cell Carcinoma ◽  
Cell Lines ◽  
Renal Cell ◽  
Migration And Invasion ◽  
Mrna Levels

592 Background: Zinc finger protein 395 (ZNF395) is frequently altered in several tumor types. However, the role of ZNF395 remains poorly studied in patients with clear cell renal cell carcinoma (RCC). In this study, we investigated the in vitro and in vivo role of ZNF395 in ccRCC. Methods: cBioPortal For Cancer Genomics was used to correlate the expression of ZNF395 with RCC patient clinical, pathological and molecular profiles. ZNF395 protein and mRNA levels were studied in several RCC cell lines in vitro. Subsequently, ZNF395 knockdown was performed in 786-O and UMRC3 RCC cells and overexpression was done in Caki-1 and 769-P RCC cells. We then evaluated ZNF395 modulation in these cell lines by in vitro MTT, migration and invasion assays. Finally, we studied the effect of ZNF395 knockout and overexpression in vivo using SCID xenograft models. Results: Patients with higher expression of ZNF395 experienced longer disease-free survival and overall survival. Using in vitro models, we confirmed that knockdown of ZNF395 decreased ZNF395 expression, and increased proliferation, migration and invasiveness of 786-O and UMRC3, while overexpression of ZNF395 increased ZNF395 expression, and reduced proliferation, migration and invasiveness of Caki-1 and 769-P. Using in vivo mouse models, knockdown of ZNF395 expression in 786-O promoted tumor growth while its overexpression in Caki-1 resulted in tumor growth inhibition. We are currently performing experiments to understand the process by which ZNF395 regulates ccRCC pathogenesis. Conclusions: Our data support the role of ZNF395 as an important tumor suppressor gene in the pathogenesis of RCC.

scholarly journals miR-202 Suppresses Cell Proliferation by Targeting FOXR2 in Endometrial Adenocarcinoma

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Xinchao Deng ◽  
Congzhe Hou ◽  
Zhen Liang ◽  
Huali Wang ◽  
Lin Zhu ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Tumor Growth ◽  
Poor Prognosis ◽  
Endometrial Adenocarcinoma ◽  
Luciferase Reporter ◽  
Candidate Target ◽  
Candidate Target Gene

Background. MicroRNA-202 (miR-202) has been reported to be aberrantly regulated in several cancers. The aim of this study is to explore the functional role of miR-202 in EAC tumor growth. Material and Methods. miR-202 expression was detected by qRT-PCR. TargetScan and luciferase reporter assay were used to elucidate the candidate target gene of miR-202. The FOXR2 protein level was assessed by Western blot and immunohistochemistry. Survival analysis was explored for FOXR2 expression in EAC patients. Results. miR-202 expression was significantly decreased in EAC tissues (P<0.01) compared with that in control tissues. And the downregulate miR-202 was significantly associated with poor prognosis (P<0.01). Re-expression of miR-202 dramatically suppressed cell proliferation in vitro and tumor growth in vivo. FOXR2 was identified as a direct target of miR-202. In EAC tissues, FOXR2 was upregulated and the increased FOXR2 was significantly associated with poor prognosis. In miR-202-transfected cells, the FOXR2 expression was inversely changed. The analysis of FOXR2 protein expression and miR-202 transcription in EAC tissues showed negative correlation (R=−0.429). Conclusion. miR-202 may function as a tumor suppressor in EAC tumor growth by targeting FOXR2 oncogene, which may provide new insights into the molecular mechanism and new targets for treatment of EAC.

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