• Radiation Oncology Journal
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• v.18 no.1
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• pp.51-58
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• 2000

Purpose :The effect of PTK inhibitors (herbimycin A and genistein) on the induction of radiation-induced apoptosis in Ph-positive KS62 leukemia cell line was investigated. Materials and Methods :K562 cells in exponential growth phase were irradiated with a linear accelerator at room temperature. For 6 MV X-ray irradiation and drug treatment, cultures were initiated at 2×106 cells/mL. The cells were irradiated with 10 Gy. Stock solutions of herbimycin A and genistein were prepared in dimethyl sulphoxide (DMSO). After incubation at 37$^{\circ}C$ for 0$\~$48 h, the extent of apoptosis was determined using agarose gel electrophoresis and TUNEL assay. The progression of cells through the cell cycle after irradiation and drug treatment was also determined with flow cytometry. Western blot analysis was used to monitor bel-2, bel-X$_{L}$ and bax protein levels. Results :Treatment with 10 Gy X-irradiation did not result in the induction of apoptosis. The HMA alone (500 nM) also failed to induce apoptosis. By contrast, incubation of K562 cells with HMA after irradiation resulted in a substantial induction of nuclear condensation and fragmentation by agarose gel electro-phoresis and TUNEL assay. Genistein failed to enhance the ability of X-irradiation to induce DNA fragmentation. Enhancement of apoptosis by HMA was not attributable to downregulation of the bel-2 or bel-X$_{L}$ anti-apoptotic proteins. When the cells were irradiated and maintained with HMA, the percentage of cells in G2/M phase decreased to 30$\~$40$\%$ at 48 h. On the other hand, cells exposed to 10 Gy X-irradiation alone or maintained with genistein did not show marked cell cycle redistribution. Conclusion : We have shown that nanomolar concentrations of the PTK inhibitor HMA synergize with X-irradiation in inducing the apoptosis in Ph (+) K562 leukemia cell line. While, genistein, a PTK inhibitor which is not selective for p210$^{bcr/abl}$ failed to enhance the radiation induced apoptosis in KS62 cells. It is unlikely that the ability of HMA to enhance apoptosis in K562 cells is attributable to bel-2 family. It is plausible that the relationship between cell cycle delays and cell death is essential for drug development based on molecular targeting designed to modify radiation-induced apoptosis.

• Journal of Life Science
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• v.27 no.2
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• pp.187-193
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• 2017

As a part of ongoing research to elucidate and characterize antiinflammatory nutraceuticals, the crude extracts from Atriplex gmelinii C. A. Mey. and their solvent-partitioned fractions were tested for their antiinflammatory potential in lipopolysaccharide (LPS)-stimulated RAW 264.7 mouse macrophages. The crude extracts of A. gmelinii C. A. Mey. were fractioned according to polarity with n-hexane, 85% aqueous methanol (85% aq. MeOH), n-butanol, and $H_2O$. Their antiinflammatory activities were investigated in LPS-induced inflammation in mouse macrophages by measuring nitric oxide (NO) generation and mRNA expression of inflammation mediators, namely, inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin-$1{\beta}$ ($IL-1{\beta}$), and IL-6. As a result, we confirmed that the crude extracts of A. gmelinii C. A. Mey. inhibited LPS-stimulated NO production and mRNA expression of iNOS and COX-2 as important inflammatory factors. The inhibition of NO production through the downregulation of important inflammatory factors such as iNOS, COX-2, $IL-1{\beta}$, and IL-6 was found by treatment with all solvent-partitioned fractions. Among all tested fractions, 85% aq. MeOH showed the strongest antiinflammatory response. Based on the current results, A. gmelinii C. A. Mey. was suggested to possess natural antiinflammatory components, indicating that it could be used as a valuable source of antiinflammatory substances.

• Journal of Life Science
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• v.27 no.2
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• pp.149-154
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• 2017

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-hodgkin lymphoma. Advances in the chemotherapeutic treatment of this disease have improved the outcomes of DLBCL; nonetheless, many patients still die of DLBCL, and therefore, a better understanding of this disease and identification of novel therapeutic targets are urgently required. In a recent gene expression profiling study, PDE (phosphodiesterase) 4B was found to be overexpressed in chemotherapy-resistant tumors. The major function of PDE4B is to inactivate the second messenger cyclic 3',5' monophosphate (cAMP) by catalyzing the hydrolysis of cAMP to 5'AMP. It is known that cAMP induces cell cycle arrest and/or apoptosis in B cells, and PDE4B abolishes cAMP's effect on B cells. However, the mechanism by which PDE4B is overexpressed remains unclear. Here, we show that the aberrant expression of miRNA may be associated with the overexpression of this gene. The PDE4B 3' untranslated region (UTR) has three functional binding sites of miR-23b, as confirmed by luciferase reporter assays. Interestingly, miR-23b-binding sites were evolutionarily conserved from humans to lizards, implying the critical role of PDE4B-miR-23b interaction in cellular physiology. The ectopic expression of miR-2 3b repressed PDE4B mRNA levels and enhanced intracellular cAMP concentrations. Additionally, miR-23b expression inhibited cell proliferation and survival of DLBCL cells only in the presence of forskolin, an activator of adenylyl cyclase, suggesting that miR-23b's effect is via the downregulation of PDE4B. These results together suggest that miR-23b could be a therapeutic target for overcoming drug resistance by repressing PDE4B in DLBCL.

• Journal of Life Science
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• v.27 no.5
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• pp.509-516
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• 2017

Perilla frutescens (L.) Britton var. sprouts (PFS) is a plant of the labiatae family. The purpose of this work was to assess the preventive effects of PFS ethanolic extracts (PFSEs) on cytokine-induced ${\beta}$-cell damage. Cytokines, which are released by the infiltration of inflammatory cells around the pancreatic islets, are involved in the pathogenesis of type 1 diabetes mellitus. The combination of interleukin-$1{\beta}$ (IL-1), interferon-${\gamma}$ (IFN-${\gamma}$), and tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) induced formation of reactive oxygen species (ROS). Accumulation of intracellular ROS led to ${\beta}$-cell dysfunction and apoptosis. PFSEs possess antioxidant activity and thus lead to downregulation of ROS generation. Cytokines decrease cell viability, stimulate the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), and induce the production of nitric oxide (NO). PFSEs prevented cytokine-induced cell viability in a dose-dependent manner. Incubation with PFSE resulted in significant reduction in cytokine-induced NO production that correlated with reduced levels of the iNOS and COX-2 protein expression. Furthermore, PFSE significantly decreased the activation of nuclear factor ${\kappa}B$ (NF-${\kappa}B$) by inhibition of $I{\kappa}B{\alpha}$ phosphorylation in RINm5F cells. In summary, our results suggest that the protective effects of PFSE might serve to counteract cytokine-induced ${\beta}$-cell destruction. Findings indicate that consumption of Perilla frutescens (L.) Britton var. sprouts alleviates hyperglycemia-mediated oxidative stress and pro-inflammatory cytokine-induced ${\beta}$-cell damage and thus has beneficial anti-diabetic effects.

• Tuberculosis and Respiratory Diseases
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• v.54 no.4
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• pp.403-414
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• 2003

Background : Proteasome inhibitors can promote either cell survival or programmed cell death, depending on both the specific type and proliferative status of the cell. However, it is not well known whether inhibition of proteasome activity is related to apoptosis in lung cancer cells. In addition, the exact mechanisms responsible for apoptosis induced by proteasome inhibition are not well understood. In the present study, we have examined the effect of proteasome inhibition on lung cancer cells and tried to test the mechanisms that may be associated with the apoptosis of these cells. Methods : We examined the effect of proteasome inhibition with MG132 or PS-341 on cell survival in A549 and NCI-H157 lung cancer cells using MTT assay, and analyzed the cleavage of PARP by Western blot analysis to find evidence of apoptosis. Next, we evaluated the activation of caspase 3 by Western blot analysis and the activity of JNK by immunocomplex kinase assay. We also examined the changes in anti-apoptotic pathways like ERK and cIAP1 by Western blot analysis after inhibition of proteasome function. Results : We demonstrated that MG132 reduced cell survival by inducing apoptosis in A549 and NCI-H157 cells. Proteasome inhibition with MG132 or PS-341 was associated with activation of caspase 3 and JNK, reduced expression of activated ERK, and downregulation of cIAP1. Conclusion : Apoptosis induced by proteasome inhibition may be associated with the activation of pro-apoptotic pathways like caspase 3 and JNK and the inactivation of anti-apoptotic pathways in lung cancer cells.

• Journal of Ginseng Research
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• v.33 no.4
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• pp.367-377
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• 2009

Halitosis is a generally accepted marker of diseases in the oral cavity and of systemic and gastrointestinal disorders. Based on these authors' previous findings (that (1) there is a close association between H. pylori infection and halitosis; (2) Korea red ginseng may suppress the colonization of H. pylori, fight H. pylori-induced cytotoxicity, and impose significant anti-inflammatory actions in patients with chronic gastritis; and (3) H. pylori infection is linked with the generation of significant levels of volatile sulfur compounds (VSCs), and the levels of VSCs correlate significantly with H. pylori-associated mucosal damages), in the current study, the authors documented the molecular mechanisms of Korea red ginseng's efficacy in ameliorating halitosis. When the RAW 264.7 cells were treated with the $H_2S$ releasing compound NaHS, the mRNA expression of cystathionine ${\gamma}$-lyase (CSE), IL-6, COX-2, and iNOS were more significantly induced compared with the vehicle-treated group. The cytoskeletal components of ezrin's and moesin's mRNA expressions were elevated by NaHS treatment accompanied by the activation of MAPK, p38, and ERK. Korea red ginseng pretreatment reduced both the NaHS-induced CSE expression and the proinflammatory genes (e.g., IL-6, COX-2, and iNOS) in a concentration-dependent manner. The ERM expression and the phosphorylation of p38 were also significantly reduced by Korea-red-ginseng pretreatment. Overall, Korea red ginseng pretreatment imposed significant anti-inflammatory effects through the downregulation of the NaHS-triggered proinflammatory gene expression, CSE, and ERM mRNA expression. Korea red ginseng could thus be said to be a key remedy of halitosis and to be effective in relieving gastric inflammation.

• Food Science and Preservation
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• v.19 no.3
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• pp.443-450
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• 2012

Recently, NADPH oxidase 4 (NOX4)-mediated generation of intracellular reactive oxygen species (ROS) was proposed to accelerate adipogenesis of 3T3-L1 cell. We have previously shown that Cheonnyuncho (Opuntia humifusa) extract significantly inhibited adipocyte differentiation via downregulation of $PPAR{\gamma}$ (peroxisome proliferator-activated receptor gamma) gene expression. In this study, we focused on the molecular mechanism(s) of NOX4, G6PDH (glucose-6-phosphate dehydrogenase) and antioxidant enzymes in anti-oxidative activities of 3T3-L1 adipocytes. Our results indicate that Cheonnyuncho extracts markedly inhibits ROS production during adipogenesis in 3T3-L1 cells. Cheonnyuncho extracts suppressed the mRNA expression of the pro-oxidant enzyme such as NOX4 and the NADPH-producing G6PDH enzyme. In addition, treatment with Cheonnyuncho extract was found to upregulate mRNA levels of antioxidant enzymes such as Mn-SOD (manganese-superoxide dismutase), Cu/Zn-SOD (copper/zinc-SOD), glutathione peroxidase (GPx), glutathion reductase (GR), and catalase, all of which are important for endogenous antioxidant responses. These data suggest that Cheonnyuncho extract may be effective in preventing the rise of oxidative stress during adipocyte differentiation through mechanism(s) that involves direct down regulation of NOX4 and G6PDH gene expression or via upregulation of endogenous antioxidant responses.

• Journal of Ginseng Research
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• v.41 no.3
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• pp.257-267
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• 2017

Background: Heat-processed ginseng, sun ginseng (SG), has been reported to have improved therapeutic properties compared with raw forms, such as increased antidiabetic, anti-inflammatory, and antihyperglycemic effects. The aim of this study was to investigate the antiobesity effects of SG through the suppression of cell differentiation and proliferation of mouse 3T3-L1 preadipocyte cells and the lipid accumulation in Caenorhabditis elegans. Methods: To investigate the effect of SG on adipocyte differentiation, levels of stained intracellular lipid droplets were quantified by measuring the oil red O signal in the lipid extracts of cells on differentiation Day 7. To study the effect of SG on fat accumulation in C. elegans, L4 stage worms were cultured on an Escherichia coli OP50 diet supplemented with $10{\mu}g/mL$ of SG, followed by Nile red staining. To determine the effect of SG on gene expression of lipid and glucose metabolism-regulation molecules, messenger RNA (mRNA) levels of genes were analyzed by real-time reverse transcription-polymerase chain reaction analysis. In addition, the phosphorylation of Akt was examined by Western blotting. Results: SG suppressed the differentiation of 3T3-L1 cells stimulated by a mixture of 3-isobutyl-1-methylxanthine, dexamethasone, and insulin (MDI), and inhibited the proliferation of adipocytes during differentiation. Treatment of C. elegans with SG showed reductions in lipid accumulation by Nile red staining, thus directly demonstrating an antiobesity effect for SG. Furthermore, SG treatment down-regulated mRNA and protein expression levels of peroxisome proliferator-activated receptor subtype ${\gamma}$ ($PPAR{\gamma}$) and CCAAT/enhancer-binding protein-alpha ($C/EBP{\alpha}$) and decreased the mRNA level of sterol regulatory element-binding protein 1c in MDI-treated adipocytes in a dose-dependent manner. In differentiated 3T3-L1 cells, mRNA expression levels of lipid metabolism-regulating factors, such as amplifying mouse fatty acid-binding protein 2, leptin, lipoprotein lipase, fatty acid transporter protein 1, fatty acid synthase, and 3-hydroxy-3-methylglutaryl coenzyme A reductase, were increased, whereas that of the lipolytic enzyme carnitine palmitoyltransferase-1 was decreased. Our data demonstrate that SG inversely regulated the expression of these genes in differentiated adipocytes. SG induced increases in the mRNA expression of glycolytic enzymes such as glucokinase and pyruvate kinase, and a decrease in the mRNA level of the glycogenic enzyme phosphoenol pyruvate carboxylase. In addition, mRNA levels of the glucose transporters GLUT1, GLUT4, and insulin receptor substrate-1 were elevated by MDI stimulation, whereas SG dose-dependently inhibited the expression of these genes in differentiated adipocytes. SG also inhibited the phosphorylation of Akt (Ser473) at an early phase of MDI stimulation. Intracellular nitric oxide (NO) production and endothelial nitric oxide synthase mRNA levels were markedly decreased by MDI stimulation and recovered by SG treatment of adipocytes. Conclusion: Our results suggest that SG effectively inhibits adipocyte proliferation and differentiation through the downregulation of $PPAR{\gamma}$ and $C/EBP{\alpha}$, by suppressing Akt (Ser473) phosphorylation and enhancing NO production. These results provide strong evidence to support the development of SG for antiobesity treatment.

• Journal of Life Science
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• v.26 no.8
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• pp.887-894
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• 2016

The extract from Artemisia annuain L.(AAE) is known as a medicinal herb that is effective against cancer. Apoptosis is the process of programmed cell death, and mitochondria are known to play a central role in cell death control. In this study, we evaluated the p53-independent apoptosis of extract of AAE through downregulation of Bcl-2 and the mitochondrial pathway in A549 (lung cancer cells). AAE may exert cancer cell apoptosis through regulating p-Akt, Cox-2, p53 and mitochondria-mediated apoptotic proteins. p-Akt/cox-2 is known to play an important role in cell proliferation and cell survival. The Bcl-2 pro-apoptotic proteins (such as Bax, Bak and Bim) mediate the permeabilization of the mitochondrial outer membrane. Treatment of AAE reduces p-Akt, p-Mdm2, cox-2 and anti-apoptotic proteins (such as Bcl-2), while tumor suppressor p53 and pro-apoptotic proteins. Activation of Bax/Bak releases cytochrome c from mitochondria to the cytosol to activate a caspase. Caspase-3 is the major effector caspase associated with apoptotic pathways. Caspase-3 generally exists in cytoplasm in the form of a pro-enzyme. In the initiation stage of apoptosis, caspase-3 is activated by proteolytic cleavage and activated caspase-3 cleaves poly (ADP-ribose) polymerase (PARP). We treated Pifithrin-α (p53 inhibitor) and Celecoxib (Cox-2 inhibitor) to learn the relationship between the signal transduction of proteins associated with apoptosis. These results suggest that AAE induces apoptosis through a p53-independent pathway in A549.

• Journal of Life Science
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• v.29 no.3
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• pp.295-302
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• 2019

Liquiritigenin (LG) is a chiral flavonoid isolated from the roots of licorice. It exhibits multiple biological activities including anti-oxidant, anti-cancer, and anti-inflammatory effects. In particular though, the anti-cancer activity of LG in oral squamous cell carcinoma has yet to be elucidated, and LG-induced apoptosis in oral squamous cell carcinoma remains poorly understood. In the present study, we tested the role of LG in inducing apoptosis in oral squamous cell carcinoma cells. LG treatment of HN22 cells resulted in a dose-dependent inhibition of cell viability as detected by a 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide assay. The induction of apoptosis in terms of Annexin V/7-Aminoactinomycin D staining, sub-G1 population, and multi-caspase activity were assessed with a $Muse^{TM}$ Cell Analyzer. Flow cytometric analysis revealed that LG treatment resulted in G2/M arrest in cell cycle progression and downregulation of cyclin B1 and CDC2 expression in a concentration-dependent manner. It also resulted in significant upregulation of p27. In addition, LG was seen to trigger the generation of reactive oxygen species and induce CCAAT/enhancer-binding protein homologous protein and 78-kDa glucose-regulated protein in concentration-dependent upregulation. The LG treatment of HN22 cells led to a loss of mitochondrial membrane potential (${\Delta}{\Psi}m$); it also reduced the levels of anti-apoptotic protein and increased the expression of apoptotic protease activating factor-1, cleaved poly (ADP-ribose)polymerase and Bax. Overall, our results indicate that the pro-apoptotic effects of LG in HN22 cells depend on the activation of both intrinsic and extrinsic signaling pathways. Thus, our results suggest that LG constitutes a natural compound with a potential role as an anti-tumor agent in oral squamous cell carcinoma.