• Asian Pacific Journal of Cancer Prevention
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• v.13 no.3
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• pp.1043-1048
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• 2012

The COPS3 gene has stimulating effect on cell proliferation and progression of osteosarcomas and related cells. However, the features of COPS3 and its potential application as a therapeutic target in other cancers has not yet been studied. In this study, therefore, the effect of COPS3 silencing via COPS3 siRNA on lung cancer cell proliferation was examined. Expression levels of COPS3 gene in COPS3 siRNA infected cells and control siRNA infected cells were compared with real time PCR and Western blot analysis. Cell proliferation levels were comprehensively analyzed by MTT, BrdU incorporationy, and colony formation assays. For mechanistic assessment the effects of COPS3 silencing on cell cycle and apoptosis were analyzed using flow cytometry. Results showed that successful silencing of the COPS3 gene at both translational and transcriptional levels significantly reduced the proliferation and colony formation by lung cancer cells (p<0.01). Flow cytometry showed cell cycle arrest in the G0/G1 phase after COPS3 silencing, and more importantly, apoptosis was induced as a result of COPS3 knockdown, which negatively affected cell survival. Therefore, these results provide another piece of important evidence that the COPS3 gene expressed in lung cancer cells may play a critical role in stimulating proliferation. Down-regulation of COPS3 could significantly inhibit lung cancer cell growth, which was most likely mediated via induction of cell cycle arrest in G0/G1 phase and apoptosis.

• The Korea Journal of Herbology
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• v.31 no.4
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• pp.71-77
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• 2016

Objectives : Adipogenesis was defined as a differentiation process of preadipocytes into the adipocytes. Thus, to control of this process can be one of the most important strategies to prevent obesity. Korean ginseng(Panax ginseng C.A. Meyer) is one of the most widely used medicinal herbs. Although multiple biological activities of Korean ginseng, particularly ginsenosides, have been known, the anti-adipogenic role and function of polysaccharides from Korean ginseng are still unclear. In this study, we examined anti-adipogenic activity of polysaccharides and its molecular basis mechanisms are further investigated.Methods : The cytotoxicity of KGP in 3T3-L1 was evaluated by MTT assay. Anti-adipogenic effect of KGP was examined by Oil Red O (ORO) staining and microscopy observation in 3T3-L1 mature adipocytes. The mRNA expression levels of adipogenic transcriptional factors were analyzed by reverse transcription-polymer chain reaction (RT-PCR). To elucidate the adipogenic molecular mechanism of KGT, SB431542 (TGF-β specific inhibitor) was used.Results : We found that polysaccharides showed no effect on the viability of 3T3-L1 preadipocytes. Dose dependent inhibitory effect of polysaccharides on 3T3-L1 adipogenesis was observed as judged by ORO staining and microscopic image analysis. To obtain further mechanistic insight into anti-adipogenic function of polysaccharides, we then tested the effect of polysaccharides treatment on the adipogenic marker genes. The mRNA expressions level of C/EBPα, PPARγ, C/EBPβ, and fatty acid synthase (FAS) were dose-dependently inhibited by KGP treatment in 3T3-L1 mature adipocytes.Conclusions : In conclusion, these findings suggest that the KGP could be used in treatment of obesity and overweight related diseases.

• The Korean Journal of Physiology and Pharmacology
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• v.5 no.5
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• pp.381-388
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• 2001

This work describes the pharmacological inhibition by KR 31378 and its acetyl metabolite, KR 31612, of the apoptotic cell death induced by $H_2O_2$ in the A7r5 cells. Exposure of A7r5 cells to $H_2O_2$ (0.5 mM) induced a concentration-dependent cytotoxicity in association with oligonucleosomal DNA fragmentation. $H_2O_2-induced$ cell death was potently suppressed by KR 31378, KR 31612, ${\alpha}-tocopherol$ or trolox. Additionally, the apoptotic death of A7r5 cells (DNA ladders on electrophoresis) was also strongly suppressed by KR 31378 and KR 31612, but to a less degree by ${\alpha}-tocopherol$ and trolox. As a mechanistic study, incubation with $H_2O_2$ markedly showed a decreased Bcl-2 level and, in contrast, increased Bax protein and cytochrome C release, which were significantly and concentration-dependently reversed by KR 31378 and KR 31612 as well as by ${\alpha}-tocopherol$ and trolox. KR 31378 and ${\alpha}-tocopherol$ significantly reduced lipid peroxidation in accordance with reduced intracellular ROS and peroxyl radical. These results suggest that KR 31378 has a therapeutic potential against the apoptotic injury via mediation of anti- oxidative stress.

• Biomolecules & Therapeutics
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• v.25 no.6
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• pp.641-647
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• 2017

Galangin (3,5,7-trihydroxyflavone) is a polyphenolic compound abundant in honey and medicinal herbs, such as Alpinia officinarum. In this study, we investigated the anti-inflammatory effects of galangin under in vitro and in vivo neuroinflammatory conditions caused by polyinosinic-polycytidylic acid (poly(I:C)), a viral mimic dsRNA analog. Galangin suppressed the production of nitric oxide, reactive oxygen species, and pro-inflammatory cytokines in poly(I:C)-stimulated BV2 microglia. On the other hand, galangin enhanced anti-inflammatory interleukin (IL)-10 production. Galangin also suppressed the expression of pro-inflammatory markers in poly(I:C)-injected mouse brains. Further mechanistic studies showed that galangin inhibited poly(I:C)-induced nuclear factor (NF)-${\kappa}B$ activity and phosphorylation of Akt without affecting MAP kinases. Interestingly, galangin increased the expression and transcriptional activity of peroxisome proliferator-activated receptor (PPAR)-${\gamma}$, known to play an anti-inflammatory role. To investigate whether PPAR-${\gamma}$ is involved in the anti-inflammatory function of galangin, BV2 cells were pre-treated with PPAR-${\gamma}$ antagonist before treatment of galangin. We found that PPAR-${\gamma}$ antagonist significantly blocked galangin-mediated upregulation of IL-10 and attenuated the inhibition of tumor necrosis factor (TNF)-${\alpha}$ and IL-6 in poly(I:C)-stimulated microglia. In conclusion, our data suggest that PI3K/Akt, NF-${\kappa}B$, and PPAR-${\gamma}$ play a pivotal role in mediating the anti-inflammatory effects of galangin in poly(I:C)-stimulated microglia.

• Applied Microscopy
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• v.47 no.4
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• pp.223-225
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• 2017

Cryo-electron microscopy (cryo-EM) is arguably the most powerful tool used in structural biology. It is an important analytical technique that is used for gaining insight into the functional and molecular mechanisms of biomolecules involved in several physiological processes. Cryo-EM can be separated into the following three groups according to the analytical purposes and the features of the biological samples: cryo-electron tomography (cryo-ET), cryo-single-particle reconstruction, and cryo-electron crystallography. Cryo-tomography is a unique EM technique that is used to study intact biomolecular complexes within their original environments; it can provide mechanistic insights that are challenging for other EM-methods. However, the resolution of reconstructed three-dimensional (3D) models generated by cryo-ET is relatively low, while single-particle reconstruction can reproduce biomolecular structures having near-atomic resolution without the need for crystallization unless the samples are large (>200 kDa) and highly symmetrical. Cryo-electron crystallography is subdivided into the following two categories according to the types of samples: one category that deals with two-dimensional (2D) crystalline arrays and the other category that uses 3D crystals. These two categories of electron-crystallographic techniques use different diffraction data obtained from still diffraction and continuous-rotation diffraction. In this paper, we review crystal-based cryo-EM techniques and focus on the recently developed 3D electron-crystallographic technique called microcrystal-electron diffraction.

• Applied Chemistry for Engineering
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• v.4 no.1
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• pp.144-152
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• 1993

Immobilized polyethylene glycols onto metal oxides such as ${\gamma}-Al_2O_3$, ${\alpha}-Al_2O_3$, $SiO_2$ and $TiO_2$ were used as phase transfer catalysts for the room temperature synthesis of aniline from nitrobenzene and ironpentacarbonyl. The amount of attached PEG molecules increased with specific surface area of metal oxides. Among the immobilized catalysts tested PEG/${\gamma}-Al_2O_3$ showed the highest activity. The reaction rate increased with the chain length of PEG mole-cules and the aqueous NaOH concentration. Mechanistic study carried out using infrared spectrometer revealed that the role of PEG was to increase the formation of $HFe(CO)_4{^-}$ ion, which is known as active species, and its movement from aqueous to organic phase.

• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.3
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• pp.233-244
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• 2015

Marine ecosystem modelling has become a more widely used decision-making tool in coastal ecosystem-based management. However, it is not trivial to develop a well calibrated/validated model with potential applicability and practicality because understanding ecological processes with complexities is a pre-requisite for developing robust ecosystem models and this accompanies a great deal of well coordinated efforts among field-going ecologists, laboratory scientists, modelers, stake-holders and managers. This report aims to provide a brief introduction on two different approaches in marine ecological models: deterministic (mechanistic) and stochastic (statistical) approach. We also included definitions, historical overview of past researches, case studies, and contextual suggestions for coastal management in Korea. A long list of references this report included in this study might be used as an introductory material for those who wish to enter ecosystem modelling field.

• Microbiology and Biotechnology Letters
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• v.38 no.1
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• pp.7-12
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• 2010

The biochemical study of sugar uptake in yeasts started five decades ago and led to the early production of abundant kinetic and mechanistic data. However, the first accurate overview of the underlying sugar transporter genes was obtained relatively late, due mainly to the genetic complexity of hexose uptake in the model yeast, Saccharomyces cerevisiae. The genomic era generated in turn a massive amount of information, allowing the identification of a multitude of putative sugar transporter and sensor-encoding genes in yeast genomes, many of which are phylogenetically related. This review aims to briefly summarize our current knowledges on the biochemical and molecular features of the transporters of pentoses in yeasts, when possible establishing links between previous kinetic studies and genomic data currently available. Emphasis is given to recent developments concerning the identification of D-xylose transporter genes, which are thought to be key players in the optimization of S. cerevisiae for bioethanol production from lignocellulose hydrolysates.

• Journal of Ginseng Research
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• v.38 no.1
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• pp.22-27
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• 2014

Background: Research has been conducted with regard to the development of methods for improving the pharmaceutical effect of ginseng by conversion of ginsenosides, which are the major active components of ginseng, via high temperature or high-pressure processing. Methods: The present study sought to investigate the anticancer effect of heat-processed American ginseng (HAG) in human gastric cancer AGS cells with a focus on assessing the role of apoptosis as an important mechanistic element in its anticancer actions. Results and Conclusion: HAG significantly reduced the cancer cell proliferation, and the contents of ginsenosides Rb1 and Re were markedly decreased, whereas the peaks of less-polar ginsenosides [20(S,R)-Rg3, Rk1, and Rg5] were newly detected. Based on the activity-guided fractionation of HAG, ginsenoside 20(S)-Rg3 played a key role in inducing apoptosis in human gastric cancer AGS cells, and it was generated mainly from ginsenoside Rb1. Ginsenoside 20(S)-Rg3 induced apoptosis through activation of caspase-3, caspase-8, and caspase-9, as well as regulation of Bcl-2 and Bax expression. Taken together, these findings suggest that heat-processing serves as an increase in the antitumor activity of American ginseng in AGS cells, and ginsenoside 20(S)-Rg3, the active component produced by heat-processing, induces the activation of caspase-3, caspase-8, and caspase-9, which contributes to the apoptotic cell death.

• Journal of Ginseng Research
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• v.40 no.4
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• pp.400-408
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• 2016

Background: Ginsenoside Rh2 (GRh2) is the main bioactive component in American ginseng, a commonly used herb, and its antitumor activity had been studied in previous studies. PDZ-binding kinase/T-LAK cell-originated protein kinase (PBK/TOPK), a serine/threonine protein kinase, is highly expressed in HCT116 colorectal cancer cells. Methods: We examined the effect of GRh2 on HCT116 cells ex vivo. Next, we performed in vitro binding assay and in vitro kinase assay to search for the target of GRh2. Furthermore, we elucidated the underlying molecular mechanisms for the antitumor effect of GRh2 ex vivo and in vivo. Results: The results of our in vitro studies indicated that GRh2 can directly bind with PBK/TOPK and GRh2 also can directly inhibit PBK/TOPK activity. Ex vivo studies showed that GRh2 significantly induced cell death in HCT116 colorectal cancer cells. Further mechanistic study demonstrated that these compounds inhibited the phosphorylation levels of the extracellular regulated protein kinases 1/2 (ERK1/2) and (H3) in HCT116 colorectal cancer cells. In vivo studies showed GRh2 inhibited the growth of xenograft tumors of HCT116 cells and inhibited the phosphorylation levels of the extracellular regulated protein kinases 1/2 and histone H3. Conclusion: The results indicate that GRh2 exerts promising antitumor effect that is specific to human HCT116 colorectal cancer cells through inhibiting the activity of PBK/TOPK.