• Korean Journal of Clinical Laboratory Science
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• v.43 no.3
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• pp.98-104
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• 2011

To evaluate the physioactivity of Salicornia herbacea L. (SH), which are obtained from Sunchon bay as wild plants, an SH extract was prepared by freeze drying to obtain SH, and by cold drying to obtain SH. For the evaluation of their bioactivities, cell viability and antioxidative effect were measured. The XTT assay was adopted to measure cell viability after C6 glioma cells were treated with various concentrations of reactive oxygen species (ROS) and hydrogen peroxide ($H_2O_2$) for 8 hours. The DPPH-radical scavenging activity was also measured for the antioxidative effect. In this study, the $XTT_{50}$ value of $H_2O_2$ was determined at $30{\mu}M$ which was highly toxic based on the cytotoxic criteria by Borenfreund and Puerner. The protective effect of SH extract significantly increased cell viability compared with $H_2O_2$-treated group. Its antioxidative effect showed a significant DPPH-radical scavenging activity at concentrations of $1-100{\mu}g/mL$, while SH extract showed highly a DPPH-radical scavenging activity at only $100{\mu}g/mL$. From these results, $H_2O_2$ was highly toxic in cultured C6 glioma cells, and SH extract was effective in the prevention of cell damage by its antioxidative effect.

• Journal of Korean Neurosurgical Society
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• v.30 no.sup1
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• pp.13-19
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• 2001

Objective : We investigated the feasibility of a double suicide gene/prodrug therapy, involving direct introduction of the herpes simplex virus Type 1 thymidine kinase(TK) gene and the Escherichia coli cytosine deaminase(CD) gene, via a recombinant adenoviral vector and ganciclovir(GCV) and/or 5-fluorocytosine(5-FC) treatment, in C6 glioma cells. Methods : Efficient gene transfer and transduction of C6 glioma cells via a recombinant adenovirus were evaluated by infecting cells with adenovirus bearing the ${\beta}$-galactosidase gene and then staining cells with 5-bromo-4-chloro-3-indolyl-13-D-galactoside. CD/TK expression in cells infected with adenovirus bearing the CD/TK gene(ad-CD/TK) was examined by immunoblotting analysis. For in vitro cytotoxicity experiments, the cells were infected with ad-CD/TK or ad-${\Delta}E1$(as a control). After addition of a variety of concentrations of GCV and 5-FU, either separately or in combination, cell viability was determined by staining the cells with crystal violet solution 6 days after infection. Result : C6 glioma cells were efficiently transduced with recombinant adenoviral vector at multiplicities of infection of 200 or more. In vitro cytotoxicity of GCV and/or 5-FC, either alone or in combination, was exclusively observed in the cells transduced with ad-CD/TK. Obvious cytotoxicity(>50% inhibition) was observed in the presence of 5-FC at concentrations greater than 30ug/ml or GCV at concentrations greater than 0.3ug/ml at a multiplicity of infection of 100. Additionally, cytotoxicity in the presence of both GCV and 5-FC was greater than that after sinlge-prodrug treatments, indicating additive effects of the prodrug treatments. Conclusion : The administration of a double-suicide gene/prodrug therapy might have great potential in the treatment of brain tumors.

• Journal of Animal Science and Technology
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• v.46 no.4
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• pp.563-570
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• 2004

The insulin-like growth factor(IGF) system, consisting of IGFs-I and -II ligands and their receptors and six IGF-binding proteins(IGFBPs), plays an important role in survival, proliferation and differentiation of a variety of cell types. Lithium is a known modulator of survival and proliferation of many cell types in vitro. The present study was undertaken to investigate the relationship between LiCI-induced changes in cell survival and growth and the expression of the IGF system components in C6 rat glioma cell line which, besides IGF-I and its receptor, is known to express IGFBP-3 as its major IGF carrier. When C6 cells were cultured for 24h in the absence or presence of 2mM or 5mM LiCl in a 10% serwn-containing medium, the viability and the number of cells were not affected by added lithium. In 72-h culture, however, C6 cells clearly exhibited a dose-dependent response to added LiCl. The cells cultured for 72h in the presence of 0, 2mM and 5mM LiCl exhibited a typical mitotic, a growth-arrested and an apoptotic appearances, respectively. Moreover, the apoptotic cells were accompanied by reduced expression of IGF-I, IGF-I receptor and IGFBP-3 as examined by semi-quantitative reverse transcription-polymerase chain reaction. Interestingly, blockade of IGFBP-3 mRNA translation by addition of 101${\mu}M$ IGFBP-3 anti-sense oligodeoxyribonucleotide in serum-free, 24-h culture resulted in a decrease in the number of cells as well as relative abundance of the target mRNA. In summary, results suggest that the cytotoxic effect of lithium in C6 cell is likely to be mediated, in part, by suppression by this agent of the expression of the IGF system components. In this regard, IGFBP-3 may play at least a 'permissive' role in normal proliferation of this cell.

• Journal of Ginseng Research
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• v.41 no.3
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• pp.386-391
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• 2017

Background: Korean Red Ginseng (KRG) is an ethnopharmacological plant that is traditionally used to improve the body's immune functions and ameliorate the symptoms of various diseases. However, the antitumorigenic effects of KRG and its underlying molecular and cellular mechanisms are not fully understood in terms of its individual components. In this study, in vitro and in vivo antitumorigenic activities of KRG were explored in water extract (WE), saponin fraction (SF), and nonsaponin fraction (NSF). Methods: In vitro antitumorigenic activities of WE, SF, and NSF of KRG were investigated in the C6 glioma cell line using cytotoxicity, migration, and proliferation assays. The underlying molecular mechanisms of KRG fractions were determined by examining the signaling cascades of apoptotic cell death by semiquantitative reverse transcriptase polymerase chain reaction and Western blot analysis. The in vivo antitumorigenic activities of WE, SF, and NSF were investigated in a xenograft mouse model. Results: SF induced apoptotic death of C6 glioma cells and suppressed migration and proliferation of C6 glioma cells, whereas WE and NSF neither induced apoptosis nor suppressed migration of C6 glioma cells. SF downregulated the expression of the anti-apoptotic gene B-cell lymphoma-2 (Bcl-2) and upregulated the expression of the pro-apoptotic gene Bcl-2-associated X protein (BAX) in C6 glioma cells but had no effect on the expression of the p53 tumor-suppressor gene. Moreover, SF treatment resulted in activation of caspase-3 as evidenced by increased levels of cleaved caspase-3. Finally, WE, SF, and NSF exhibited in vivo antitumorigenic activities in the xenograft mouse model by suppressing the growth of grafted CT-26 carcinoma cells without decreasing the animal body weight. Conclusion: These results suggest that WE, SF, and NSF of KRG are able to suppress tumor growth via different molecular and cellular mechanisms, including induction of apoptosis and activation of immune cells.

• Archives of Pharmacal Research
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• v.22 no.5
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• pp.448-453
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• 1999

In ginsenoside Rh2-treated rat glioma C6Bu-1 cells, apoptotic morphological changes, such as cell shrinkage, chromatin condensation and pyknosis were confirmed by means of electron microscopy. To evaluate whether induction of apoptosis by ginsenoside Rh2 is mediated by the members of Bcl-2 family, we first established C6Bu-1 cells overexpressing Bcl-2. It was demonstrated that the expression of Bcl-2, Bcl-xL, and Bax was not altered in ginsenoside Rh2-treated C6Bu-1 overexpressing C6Bu-1 cells failed to prevent from ginsenoside Rh2-induced cell death. These results suggest the existence of other apoptotic pathway that requires induction of apoptosis by ginsenoside Rh2 rather than the pathway through Bcl-2, $Bcl-x_{L}$ or Bax in C6Bu-1 cells.

• Journal of Korean Neurosurgical Society
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• v.29 no.4
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• pp.471-476
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• 2000

Objective : p16/INK4a, a kind of tumor suppressor genes, encodes a specific inhibitor of the cyclin D-dependent kinases CDK4 and CDK6. This prevents the association of CDK4 with cyclin D1, and subsequently inhibits phosphorylation of retinoblastoma tumor suppressor protein(pRb), thus preventing exit from the G1 phase. According to previous reports, over 50% of glioma tissue and 80% of glioma cell lines have been demonstrated inactivation of p16/INK4a gene. The purpose of this study was to determine whether recombinant adenovirus-p16 virus is a suitable candidate for gene replacement therapy in cases of glioma. Methods : Three human glioma cell lines(U251MG, U87MG and U373MG) that express mutant p16 protein were used. Replication-deficient adenovirus was utilized as an expression vector to transfer exogenous p16 cDNA into the cells ; control cells were infected with the Ad-${\beta}$-gal expressing ${\beta}$-galactosidase. To monitor gene transfer and the expression of exogenous genes, we used Western Blotting analysis. Flow cytometry studies of cellular DNA content were performed to determine the cell cycle phenotype of the glioma cells before and after treatment. Results : We showed here that restoration of p16/INK4a expression in p16 negative U87MG, U251MG and partially deleted U373MG by Ad-CMV-p16 induced growth suppression in vitro. Flow cytometric study revealed that Ad-CMV-p16 infected U87MG cells were arrested during the G0-G1 phase of the cell cycle. Expression of p16 transferred by Ad-CMV-p16 in glioma cells was highly efficient and maintained for more than seven days. Conclusions : Our results suggest that Ad-CMV-p16 gene therapy strategy is potentially useful and warrants further clinical investigation for the treatment of gliomas.

• YAKHAK HOEJI
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• v.60 no.2
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• pp.92-99
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• 2016

Parkinson's disease (PD) is one of the representative neurodegenerative movement disorders with the selective loss of dopaminergic neurons in the substantia nigra. 6-Hydroxydopamine (6-OHDA) is widely used as an experimental model system to mimic PD and has been reported to cause neuronal cell death via oxidative and/or nitrosative stress. Therefore, daily intake of dietary or medicinal plants which fortifies cellular antioxidant capacity can exert neuroprotective effects in PD. In the present study, we have investigated the protective effect of Korean red ginseng (KRG) against 6-OHDA-induced nitrosative death in C6 glioma cells. Treatment of C6 cells with 6-OHDA decreased cell viability and increased expression of inducible nitric oxide synthase, production of nitric oxide as well as peroxynitrite, and formation of nitrotyrosine. 6-OHDA led to apoptotic cell death as determined by decreased Bcl-2/Bax, phosphorylation of JNK, activation of caspase-3, and cleavage of PARP. Conversely, pretreatment of C6 cells with KRG attenuated 6-ODHA-induced cytotoxicity, apoptosis, and nitrosative damages. To further elucidate the molecular mechanism of KRG protection against 6-OHDA-induced nitrosative cell death, we have focused on the cellular self-defense molecules against exogenous noxious stimuli. KRG treatment up-regulated heme oxygenase-1 (HO-1), a key antioxidant enzyme essential for cellular defense against oxidative and/or nitrosative stress via activation of Nrf2. Taken together, these findings suggest KRG may have preventive and/or therapeutic potentials for the management of PD.

• Journal of Acupuncture Research
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• v.21 no.3
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• pp.29-41
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• 2004

Objective : This study was produced to examine the effects of moxibustion that had been played important role to traditional oriental medical treatment on disease. Recently, it was reported that moxi-tar which is generated in the process of moxibustion as burning combustibles decreased NO and iNOS generation in C6-glioma and RAW 264.7 cells in our lab. Methods : C6-glioma cells were cultured in RPMI 1640 with FBS 10% in CO2 incubator. To study the protective effects of moxi-tar, we observed cell viability, DPPH activity, SOD activity, catalase activity and cell morphology after injury with $H_2O_2$. Results and Conclusions : Moxi-tar increased cell viability about twice as much as that of being injury by $H_2O_2$(moxi-tar $40{\mu}g/m{\ell}$, $H_2O_2$ $500{\mu}M$). And the results of free radical scavenger activity($80{\mu}g/m{\ell}$ : $78.91{\pm}4.4%$), SOD activity and catalase activity($80{\mu}g/m{\ell}$ : 21.6unit/mg protein) were increased by moxi-tar as dose-dependent manner. So we concluded that the effects of moxibustion which is played important role in Oriental medicine, might be free radical scavenger effects induced by moxi-tar. Conclusion : These results indicate that tBHP induces apoptosis through a lipid peroxidation-dependent mechanism and JS exerts the protective effect against the apoptosis by preventing peroxidation of membrane lipids.

• Korean Journal of Pharmacognosy
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• v.44 no.3
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• pp.263-268
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• 2013

The protective role against oxidative stress under cellular system using C6 glioma cells was studied using the ethyl acetate (EtOAc) fraction, luteolin (1), and luteolin-7-glucoside (2) of Taraxacum coreanum. C6 glioma cells showed low cell viability and high generation of reactive oxygen species (ROS) by the treatment with generator of hydrogen peroxide ($H_2O_2$) and amyloid beta ($A{\beta}_{25-35}$). However, the treatment of the EtOAc fraction attenuated the cellular oxidative stress, resulting in significant elevation of cell viability. In addition, the production of ROS formation was also decreased by the treatment of the EtOAc fraction. Compounds 1 and 2 were isolated from the EtOAc fraction, and the protective effect was evaluated. Compounds 1 and 2 led to the increase of cell viability and decrease of production of ROS against oxidative stress by $H_2O_2$ and $A{\beta}_{25-35}$. The present study indicated that the EtOAc fraction, compounds 1 and 2 from T. coreanum demonstrated protective effects against oxidative stress, suggesting the preventive role against neurodegenerative diseases.

• BMB Reports
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• v.44 no.7
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• pp.452-457
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• 2011

The Egr-1 is an immediate early response gene encoding a transcription factor that functions in the regulation of cell growth, differentiation, and apoptosis. Estrogen has diverse physiological effects, including cellular proliferation and neuroprotection against brain injury. There are two types of estrogen receptors (ERs), $ER{\alpha}$ and $ER{\beta}$. $ER{\alpha}$-induced Egr-1 expression has been extensively studied; however, the role of $ER{\beta}$ is yet not known. In the present study, we investigated whether or not $ER{\beta}$ induces Egr-1 expression in C6 rat glioma cells, which express $ER{\beta}$ but not $ER{\alpha}$. Our results show that $ER{\beta}$ promoted up-regulation of Egr-1 expression via a non-genomic mechanism involving the Raf/MEK1/Erk/Elk-1 signaling cascade.