• BMB Reports
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• v.44 no.8
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• pp.547-552
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• 2011

MED19 is a member of the Mediator that plays a key role in the activation and repression of signal transduction or the regulation of transcription in carcinomas. To tested the functional role of MED19 in human prostate cancer, we downregulated MED19 expression in prostate cancer cells (PC-3 and DU145) by lentivirus-mediated short hairpin (shRNA), and analyzed the effect of inhibition of MED19 on prostate cancer cell proliferation and tumorigenesis. The in vitro prostate cancer cell proliferation, colony formation, and in vivo tumor growth in nude mice xenografts was significantly reduced after the downregulation of MED19. Knockdown of MED19 caused S-phase arrest and induced apoptosis via modulation of Bid and Caspase 7. It was suggested that MED19 serves as a novel proliferation regulator that promotes growth of prostate cancer cells.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.5
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• pp.1418-1425
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• 2004

The water extract of Chongmyung-tang has been traditionally used for treatment of memory-disorder in oriental medicine. This study was designed to investigate the protective mechanisms of Chongmyung-tang on β-amyloid or H₂O₂-induced cytotoxicity in Neuro 2A cells. The water extract of Chongmyung-tang significantly reduced both β-amyloid or H₂O₂-induced cell death and apoptotic characteristics through reduction of intracellular peroxide generation. Also, it inhibited the mitochondrial dysfunction including the disruption of mitochondria membrane permeability transition(MPT) and the modulation in expression of Bcl-2 family proteins in H₂O₂-treated H9c2 cells. Furthermore, pretreatment of quercetin inhibited the activation of caspase-3, in turn, degradation of ICAD/DFF45 were completely abolished in H₂O₂-treated cells. Taken together, that data suggest that the protective effects of the water extract of Chongmyung-tang against β-amyloid induced oxidative injuries may be achieved through modulation of mitochondrial dysfunction.

• The Journal of Korean Medicine
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• v.25 no.2
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• pp.138-150
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• 2004

Objectives : Alzheimer's disease (AD) is a geriatric dementia that is widespread in old age. In the near future AD will be the biggest problem in public health service. Although a variety of oriental prescriptions, including Sesim-tang, have been traditionally utilized for the treatment of AD, their pharmacological effects and action mechanisms have not yet been fully elucidated. The present study investigated the effects of Sesim-tang on apoptotic cell death induced by CT105 (carboxy terminal 105 amino acid peptide fragment of APP) overexpression in SK-N-SH neuroblastoma cell lines. Methods: We studied the regenerative and inhibitory effects on Alzheimer's disease in CT105-induced SK-N-SH cell lines by Sesim-tang water extract. We examined for cell morphological pattern, DNA fragmentation, LDH activity assay, zymography assay, and immunohistochemistric analysis. Additionally, we investigated the association between the CT105 and neurite degeneration caused by CT105-induced apoptotic response in neurone cells. Results: Findings from our experiments have shown that Sesim-tang inhibits the synthesis or activities of CT105, which has neurotoxicities and apoptotic activities in the cell line. In addition, pretreatment with Sesim-tang ($>50\mu\textrm{g}/ml$ for 12 hours) partially prevented CT105-induced cytotoxicity in SK-N-SH cell lines. SK-N-SH cell lines overexpressed with CT105 exhibited remarkable apoptotic cell damage. Based on morphological observations by phase-contrast microscope and LDH activity measurements in the culture media, the CT105-induced cell death was significantly inhibited by Sesim-tang water extract. Sesim-tang was found to reduce the expression of APP and caspase-3 induced by CT105 in SK-N-SH cell lines and in rat hippocampus. Conclusions: As the result of this study, in the Sesim-tang group, apoptosis in the nervous system is inhibited, the repair against the degeneration of SK-N-SH cell lines by CT105 expression is promoted. Hence, Sesim-tang may be beneficial for the treatment of AD.

• Biomolecules & Therapeutics
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• v.25 no.5
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• pp.519-527
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• 2017

Excessive activation of microglia causes the continuous production of neurotoxic mediators, which further causes neuron degeneration. Therefore, inhibition of microglial activation is a possible target for the treatment of neurodegenerative disorders. Balanophonin, a natural neolignoid from Firmiana simplex, has been reported to have anti-inflammatory and anti-cancer effects. In this study, we aimed to evaluate the anti-neuroinflammatory effects and mechanism of balanophonin in lipopolysaccharide (LPS)-stimulated BV2 microglia cells. BV2 microglia cells were stimulated with LPS in the presence or absence of balanophonin. The results indicated that balanophonin reduced not only the LPS-mediated TLR4 activation but also the production of inflammatory mediators, such as nitric oxide (NO), prostaglandin E2 (PGE2), $Interleukin-1{\beta}$ ($IL-1{\beta}$), and tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$), in BV2 cells. Balanophonin also inhibited LPS-induced inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX2) protein expression and mitogen activated protein kinases (MAPKs), including extracellular signal-regulated kinase (ERK1/2), c-Jun N-terminal kinase (JNK), and p38 MAPK. Interestingly, it also inhibited neuronal cell death resulting from LPS-activated microglia by regulating cleaved caspase-3 and poly ADP ribose polymerase (PARP) cleavage in N2a cells. In conclusion, our data indicated that balanophonin may delay the progression of neuronal cell death by inhibiting microglial activation.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.2
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• pp.544-552
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• 2004

In oriental medicine, Radix Polygalae(RP) has been to treat tremors et al. But the mechanism how to decrease tremors was not known. The purpose of this study was to investigate the effect of RP on neurodegenerative disease. We used RP to execute the study of this defense mechanism on dopamine-induced cell death in human SH-SY5Y dopaminergic neuroblastoma cells. MTT assay was used to know the cytotoxicity of dopamine and the defense mechanism. As a result of this experiment, dopamine had cytotoxicity in human SH-SY5Y cells, but when it treated with RP, the cell survival rate increased. This suppressed the cell apoptosis, activation of caspase-3 protease, production of ROS, and repair of membrane potential change. In conclusion, RP has the protective effect on dopamine-induced cell death in human SH-SY5Y dopaminergic neuroblastoma cells, so this could be an effective agent on the neurodegenerative disease like Parkinsonism.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.6
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• pp.2569-2574
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• 2015

Necroptosis, also known as "programmed necrosis", has emerged as a critical factor in a variety of pathological and physiological processes and is considered a cell type-specific tightly regulated process with mechanisms that may vary rather greatly due to the change of cell line. Here we used HT-29, a human colon cancer cell line, to establish a necroptosis model and elucidate associated mechanisms. We discovered that cobalt chloride, a reagent that could induce hypoxia-inducible $factor-1{\alpha}(HIF1{\alpha})$ expression and therefore mimic the hypoxic microenvironment of tumor tissue in some aspects induces necroptosis in HT-29 cells when caspase activity is compromised. On the other hand, apoptosis appears to be the predominant death form when caspases are functioning normally. HT-29 cells demonstrated significantly increased RIPK1, RIPK3 and MLKL expression in response to cobalt chloride plus z-VAD treatment, which was accompanied by drastically increased $IL1{\alpha}$ and IL6 expression, substantiating the notion that necrosis can induce profound immune reactions. The RIPK1 kinase inhibitor necrostatin-1 and the ROS scavenger NAC each could prevent necrosis in HT-29 cells and the efficiency was enhanced by combined treatment. Thus by building up a necroptosis model in human colon cancer cells, we uncovered that mechanically RIP kinases collaborate with ROS during necrosis promoted by cobalt chloride plus z-VAD, which leads to inflammation. Necroptosis may present a new target for therapeutic intervention in cancer cells that are resistant to apoptotic cell death.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.6
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• pp.2425-2430
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• 2015

Clinical resistance to chemotherapeutic agents is one of the major hindrances in the treatment of human cancers. EHZ2 is involved in drug resistance and is overexpressed in drug-resistant cancer cell lines. In this study, we investigated the effects of EHZ2 on cisplatin -resistance in A549/DDP and AGS/DDP cells. EHZ2 mRNA and protein were found to be significantly overexpressed in A549/DDP and AGS/DDP cells, compared to parental cells. EHZ2 siRNA successfully silenced EHZ2 mRNA and protein expression. Proliferation was inhibited and drug resistance to cisplatin was improved. Flow cytometry showed that silencing of EHZ2 arrested A549/DDP and AGS/DDP cells in the G0/G1 phase, increasing apoptosis, rh-123 fluorescence intensity and caspase-3/8 activities. Silencing of EHZ2 also significantly reduced the mRNA and protein expression levels of cyclin D1 and MDR1,while up-regulating p15, p21, p27 and miR-218 in A549/DPP cells. Furthermore, silencing of EHZ2 also significantly increased the expression level of tumor suppressor factor miR-218. We also found down-regulating EHZ2 expression increased methylation in A549/DDP and AGS/DDP cells. This study demonstrates that drug resistance can be effectively reversed in human cisplatin-resistant lung and gastric cancer cells through delivery of siRNAs targeting EHZ2.

• The Journal of the Korea Contents Association
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• v.14 no.6
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• pp.241-246
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• 2014

Acute promyelocytic leukemia (APL) is a cancer of the blood. Although electron beam (EB) irradiation is used with other anti-cancer agents, EB irradiation can be harmful to normal tissues around the cancer. In the present study, we evaluate the differential cytotoxic effect of EB irradiation with other molecules, including TNF-${\alpha}$, on DMSO-treated HL-60 cells and HL-60 cells. HL-60 cells are the human promyleocytic leukemia cell line and are differentiated by DMSO. DMSO-treated HL-60 cells are considered to be normal granulocytic cells. In these results, TNF-${\alpha}$ may be used as the potential agent for the treatment of blood cancer without side effects in low dose of EB irradiation therapy.

• The Korean Journal of Physiology and Pharmacology
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• v.9 no.6
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• pp.315-322
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• 2005

In this study, the authors investigated whether death of vascular smooth muscle cell (VSMC) had a pathological pertinence. Conditioned media obtained from rat aorta smooth muscle cell (SMC) that were induced death by expressing FADD in the absence of tetracycline (FADD-SMC) triggered death of normal SMC. DNA fragmentation and caspase-3 activation were observed in dying SMC by conditioned media. FADD-SMC showed transcriptional activation of tumor necrosis factor $(TNF)-{\alpha}$. Conditioned medium contained $TNF-{\alpha}$, indicating secretion of the cytokine from dying FADD-SMC. It was investigated if secreted $TNF-{\alpha}$ was functional. Conditioned medium activated ERK and p38 MAPK pathways and induced MMP-9 expression, whereas depletion of the cytokine with its soluble receptor (sTNFR) remarkably inhibited induction of MMP-9 by conditioned medium. These findings suggest that $TNF-{\alpha}$ in conditioned medium seems to be active. Then, contribution of $TNF-{\alpha}$ on death-inducing activity of conditioned medium was examined. Depletion of $TNF-{\alpha}$ with soluble $TNF-{\alpha}$ receptor decreased the death activity of conditioned medium by 35%, suggesting that $TNF-{\alpha}$ play a partial role in the death activity. Boiling of medium almost completely abolished the death-inducing activity, suggesting that other heat labile death inducing proteins existed in conditioned medium. Taken together, these results indicate that SMC undergoing death could contribute to inflammation by expressing inflammatory cytokines and pathological complications by inducing death of neighboring cells.

• Preventive Nutrition and Food Science
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• v.16 no.1
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• pp.18-23
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• 2011

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by neuronal loss and extracellular senile plaques containing $\beta$-amyloid peptide (A$\beta$). The deposition of the A$\beta$ peptide following proteolytic processing of amyloid precursor protein (APP) by $\beta$-secretase (BACE1) and $\gamma$-secretase is a critical feature in the progression of AD. Among the plant extracts tested, the ethanol extract of Petasites japonicus leaves showed novel protective effect on B103 neuroblastoma cells against neurotoxicity induced by A$\beta$, as well as a strong suppressive effect on BACE1 activity. Ethanol extracts of P. japonicus leaves were sequentially extracted with methylene chloride, ethyl acetate and butanol and evaluated for potential to inhibit BACE1, as well as to suppress A$\beta$-induced neurotoxicity. Exposure to A$\beta$ significantly reduced cell viability and increased apoptotic cell death. However, pretreatment with ethyl acetate fraction of P. japonicus leaves prior to A$\beta$ (50 ${\mu}M$) significantly increased cell viability (p<0.01). In parallel, cell apoptosis triggered by A$\beta$ was also dramatically inhibited by ethyl acetate fraction of P. japonicus leaves. Moreover, the ethyl acetate fraction suppressed caspase-3 activity to the basal level at 30 ppm. Taken together, these results demonstrated that P. japonicus leaves appear to be a useful source for the inhibition and/or prevention of AD by suppression of BACE1 activity and attenuation of A$\beta$ induced neurocytotoxicity.