• BMB Reports
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• 제44권3호
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• pp.158-164
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• 2011

Gliomas are the most frequently occurring primary malignancies in the central nervous system, and glioblastoma multiforme (GBM) is the most common and most aggressive of these tumors. Despite vigorous basic and clinical studies over past decades, the median survival of patients with this disease remains at about one year. Recent studies have suggested that GBMs contain a subpopulation of tumor cells that displays stem cell characteristics and could therefore be responsible for in vivo tumor growth. We will summarize the major oncogenic pathways abnormally regulated in gliomas, and review the recent findings from mouse models that our laboratory as well as others have developed for the study of GBM. The concept of cancer stem cells in GBM and their potential therapeutic importance will also be discussed.

• Asian Pacific Journal of Cancer Prevention
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• 제15권11호
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• pp.4499-4505
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• 2014

Glioblastoma, the most aggressive and malignant form of glioma, appears to be resistant to various chemotherapeutic agents. Hence, approaches have been intensively investigated to targeti specific molecular pathways involved in glioblastoma development and progression. Aloe emodin is believed to modulate the expression of several genes in cancer cells. We aimed to understand the molecular mechanisms underlying the therapeutic effect of Aloe emodin on gene expression profiles in the human U87 glioblastoma cell line utilizing microarray technology. The gene expression analysis revealed that a total of 8,226 gene alterations out of 28,869 genes were detected after treatment with $58.6{\mu}g/ml$ for 24 hours. Out of this total, 34 genes demonstrated statistically significant change (p<0.05) ranging from 1.07 to 1.87 fold. The results revealed that 22 genes were up-regulated and 12 genes were down-regulated in response to Aloe emodin treatment. These genes were then grouped into several clusters based on their biological functions, revealing induction of expression of genes involved in apoptosis (programmed cell death) and tissue remodelling in U87 cells (p<0.01). Several genes with significant changes of the expression level e.g. SHARPIN, BCAP31, FIS1, RAC1 and TGM2 from the apoptotic cluster were confirmed by quantitative real-time PCR (qRT-PCR). These results could serve as guidance for further studies in order to discover molecular targets for the cancer therapy based on Aloe emodin treatment.

• Journal of Korean Neurosurgical Society
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• 제63권4호
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• pp.444-454
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• 2020

Objective : Glioblastoma multiforme (GBM) is the most aggressive for of brain tumor and treatment often fails due to the invasion of tumor cells into neighboring healthy brain tissues. Activation of the Janus kinase-signal transducer and activator of transcription (JAK/STAT) signaling pathway is essential for normal cellular function including angiogenesis, and has been proposed to have a pivotal role in glioma invasion. This study aimed to determine the dose-dependent effects of ruxolitinib, an inhibitor of JAK, on the interferon (IFN)-I/IFN-α/IFN-β receptor/STAT and IFN-γ/IFN-γ receptor/STAT1 axes of the IFN-receptor-dependent JAK/STAT signaling pathway in glioblastoma invasion and tumorigenesis in U87 glioblastoma tumor spheroids. Methods : We administered three different doses of ruxolitinib (50, 100, and 200 nM) to human U87 glioblastoma spheroids and analyzed the gene expression profiles of IFNs receptors from the JAK/STAT pathway. To evaluate activation of this pathway, we quantified the phosphorylation of JAK and STAT proteins using Western blotting. Results : Quantitative real-time polymerase chain reaction analysis demonstrated that ruxolitinib led to upregulated of the IFN-α and IFN-γ while no change on the hypoxia-inducible factor-1α and vascular endothelial growth factor expression levels. Additionally, we showed that ruxolitinib inhibited phosphorylation of JAK/STAT proteins. The inhibition of IFNs dependent JAK/STAT signaling by ruxolitinib leads to decreases of the U87 cells invasiveness and tumorigenesis. We demonstrate that ruxolitinib may inhibit glioma invasion and tumorigenesis through inhibition of the IFN-induced JAK/STAT signaling pathway. Conclusion : Collectively, our results revealed that ruxolitinib may have therapeutic potential in glioblastomas, possibly by JAK/STAT signaling triggered by IFN-α and IFN-γ.

• Journal of Korean Neurosurgical Society
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• 제29권4호
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• pp.477-484
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• 2000

Objective : Despite advances in the understanding of tumor biology and the tumor immunology, there has been no effective treatment. The Intercellular adhesion molecule-1(ICAM-1) has been shown to be important in interaction involving cells of the immune system and to be upregulated in a number of cell culture systems by cytokines, including immune interferon($IFN-{\gamma}$) and tumor necrosis $factor-{\alpha}$($TNF-{\alpha}$). ICAM-1 has been identified as one of the ligands for lymphocyte function-associated antigen-1(LFA-1). The effectiveness of various cytokines to ICAM-1 induction on cultured human glioblastoma cell lines and potential efficacy of immunotherapy were studied. Method : Human glioblastoma cell lines, U-251 MG, U-373 MG were trypsinized and suspended at $1{\times}10^5cells/ml$ and grown on 8 well chamber slide, the cells were incubated in 0.3ml medium alone or medium containing $IFN-{\gamma}$(1000U/ml) or $TNF-{\alpha}$(250U/ml) or $IFN-{\gamma}$ plus $TNF-{\alpha}$ for 6, 12, 24, 48 and 72 hours. The coverslip were then removed and stained with a 1/30 dilution of anti-ICAM-1 antibody. Result : Surface antigen expression of ICAM-1 was increased by incubating glioblastoma cell lines with $IFN-{\gamma}$ and $TNF-{\alpha}$. Combined effect of $IFN-{\gamma}$ and $TNF-{\alpha}$ has induced more ICAM-1 expression on glioblastoma cell lines. Upregulation of ICAM-1 expression in an established glioblastoma cell line was of greater magnitude and more rapid following incubation with $IFN-{\gamma}$ plus $TNF-{\alpha}$. Surface antigen expression of ICAM-1 was increased for up to 48 hours after cytokine treatment on both cell lines(p<0.05). There was no difference on both cell lines(p>0.05). Conclusion : The results of the present study indicate that ICAM-1 expression in glioblastoma cell lines, U-251 MG and U-373 MG, are induced and enhanced after treatment with $IFN-{\gamma}$ and $TNF-{\alpha}$. Combined effect of $IFN-{\alpha}$ and $TNF-{\gamma}$ is stronger and more rapid than $IFN-{\gamma}$ or $TNF-{\alpha}$ alone.

• Asian Pacific Journal of Cancer Prevention
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• 제17권3호
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• pp.1553-1564
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• 2016

Identification of novel therapeutics in glioblastoma remains crucial due to the devastating and infiltrative capacity of this malignancy. The current study was aimed to appraise effect of arsenic trioxide (ATO) in U87MG cells. The results demonstrated that ATO induced apoptosis and impeded proliferation of U87MG cells in a dose-dependent manner and also inhibited classical NF-${\kappa}B$ signaling pathway. ATO further upregulated expression of Bax as an important proapoptotic target of NF-${\kappa}B$ and also inhibited mRNA expression of survivin, c-Myc and hTERT and suppressed telomerase activity. Moreover, ATO significantly increased adhesion of U87MG cells and also diminished transcription of NF-${\kappa}B$ down-stream targets involved in cell migration and invasion, including cathepsin B, uPA, MMP-2, MMP-9 and MMP-14 and suppressed proteolytic activity of cathepsin B, MMP-2 and MMP-9, demonstrating a possible mechanism of ATO effect on a well-known signaling in glioblastoma dissemination. Taken together, here we suggest that ATO inhibits survival and invasion of U87MG cells possibly through NF-${\kappa}B$-mediated inhibition of survivin and telomerase activity and NF-${\kappa}B$-dependent suppression of cathepsin B, MMP-2 and MMP-9.

• International Journal of Stem Cells
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• 제16권3호
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• pp.315-325
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• 2023

Background and Objectives: Glioblastoma (GBM) is an aggressive primary brain tumor characterized by its heterogeneity and high recurrence and lethality rates. Glioblastoma stem cells (GSCs) play a crucial role in therapy resistance and tumor recurrence. Therefore, targeting GSCs is a key objective in developing effective treatments for GBM. The role of Parathyroid hormone-related peptide (PTHrP) in GBM and its impact on GSCs remains unclear. This study aimed to investigate the effect of PTHrP on GSCs and its potential as a therapeutic target for GBM. Methods and Results: Using the Cancer Genome Atlas (TCGA) database, we found higher expression of PTHrP in GBM, which correlated inversely with survival. GSCs were established from three human GBM samples obtained after surgical resection. Exposure to recombinant human PTHrP protein (rPTHrP) at different concentrations significantly enhanced GSCs viability. Knockdown of PTHrP using target-specific siRNA (siPTHrP) inhibited tumorsphere formation and reduced the number of BrdU-positive cells. In an orthotopic xenograft mouse model, suppression of PTHrP expression led to significant inhibition of tumor growth. The addition of rPTHrP in the growth medium counteracted the antiproliferative effect of siPTHrP. Further investigation revealed that PTHrP increased cAMP concentration and activated the PKA signaling pathway. Treatment with forskolin, an adenylyl cyclase activator, nullified the antiproliferative effect of siPTHrP. Conclusions: Our findings demonstrate that PTHrP promotes the proliferation of patient-derived GSCs by activating the cAMP/PKA signaling pathway. These results uncover a novel role for PTHrP and suggest its potential as a therapeutic target for GBM treatment.

• The Korean Journal of Physiology and Pharmacology
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• 제21권5호
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• pp.509-518
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• 2017

Glioblastoma multiforme (GBM) is the most common primary intracranial tumor in adults and has poor prognosis. The GBM-specific tumor microenvironment (TME) plays a crucial role in tumor progression, immune escape, local invasion, and metastasis of GBM. Here, we demonstrate that hypoxia, reactive oxygen species (ROS), and differential concentration of glucose influence the expression of cytokines and chemokines, such as IL-6, IL-8, and IP-10, in human glial cell lines. Treatment with cobalt chloride ($CoCl_2$) and hydrogen peroxide ($H_2O_2$) significantly increased the expression levels of IL-6, IL-8, and IP-10 in a dose-dependent manner in CRT-MG and U251-MG astroglioma cells, but not in microglia cells. However, we found strikingly different patterns of expression of cytokines and chemokines between $H_2O_2$-treated CRT-MG cells cultured in low- and high-glucose medium. These results suggest that astroglioma and microglia cells exhibit distinct patterns of cytokine and chemokine expression in response to $CoCl_2$ and $H_2O_2$ treatment, and different concentrations of glucose influence this expression under either hypoxic or oxidant-enriched conditions.

• IMMUNE NETWORK
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• 제16권3호
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• pp.183-188
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• 2016

Sirtuin family members with lysine deacetylase activity are known to play an important role in anti-aging and longevity. Cellular senescence is one of the hallmarks of aging, and downregulation of sirtuin is reported to induce premature senescence. In this study, we investigated the effects of small-molecule sirtuin inhibitors on cellular senescence. Various small molecules such as tenovin-1 and EX527 were employed for direct sirtuin activity inhibition. U251, SNB-75, and U87MG glioblastoma cells treated with sirtuin inhibitors exhibited phenotypes with nuclear enlargement. Furthermore, treatment of rat primary astrocytes with tenovin-1 also increased the size of the nucleus. The activity of senescence-associated β-galactosidase, a marker of cellular senescence, was induced by tenovin-1 and EX527 treatment in U87MG glioblastoma cells. Consistent with the senescent phenotype, treatment with tenovin-1 increased p53 expression in U87MG cells. This study demonstrated the senescence-inducing effect of sirtuin inhibitors, which are potentially useful tools for senescence research.

• BMB Reports
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• 제51권10호
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• pp.481-483
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• 2018

Glioblastoma (GBM) is the most common and aggressive form of human adult brain malignancy. The identification of the cell of origin harboring cancer-driver mutations is the fundamental issue for understanding the nature of GBM and developing the effective therapeutic target. It has been a long-term hypothesis that neural stem cells in the subventricular zone (SVZ) might be the origin-of-cells in human glioblastoma since they are known to have life-long proliferative activity and acquire somatic mutations. However, the cell of origin for GBM remains controversial due to lack of direct evidence thereof in human GBM. Our recent study using various sequencing techniques in triple matched samples such as tumor-free SVZ, tumor, and normal tissues from human patients identified the clonal relationship of driver mutations between GBM and tumor-free SVZ harboring neural stem cells (NSCs). Tumor-free SVZ tissue away from the tumor contained low-level GBM driver mutations (as low as 1% allelic frequency) that were found in the dominant clones in its matching tumors. Moreover, via single-cell sequencing and microdissection, it was discovered that astrocyte-like NSCs accumulating driver mutations evolved into GBM with clonal expansion. Furthermore, mutagenesis of cancer-driving genes of NSCs in mice leads to migration of mutant cells from SVZ to distant brain and development of high-grade glioma through the aberrant growth of oligodendrocyte precursor lineage. Altogether, the present study provides the first direct evidence that NSCs in human SVZ is the cell of origin that develops the driver mutations of GBM.

• The Korean Journal of Physiology and Pharmacology
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• 제12권5호
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• pp.225-230
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• 2008

Netrins are secreted molecules and involved in axon guidance, cell migration and tumor development. Recent studies revealed that netrins perform novel functions in such processes as epithelial development and angiogenesis without operating through the classical netrin receptors, DCC (Deleted in Colorectal Cancer) and Unc5h. In the present study, we investigated the roles of netrin-1 and its receptors in cell spreading of human glioblastoma cells, and found that netrin-1 haptotactically enhanced fibronectin-induced cell spreading and focal adhesion formation in U373 glioblastoma cells. Netrin-1 binding to the U373 cell membrane was blocked by an antibody against ${\alpha}v$ integrin subunit, but not by an anti-DCC or anti-Unc5h antibody. In addition, enhancement of the fibronectin response by netrin-1 was abrogated by a function blocking antibody against integrin ${\alpha}v{\beta}3$. Since the ${\alpha}v$ subunit of the integrin family plays an important role in the pathophysiological aspects of cell migration, including tumor angiogenesis and metastasis, our data provide important insight into the molecular mechanism of netrin function.