• Journal of Photoscience
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• v.9 no.2
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• pp.221-224
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• 2002

Carcinogenesis can be theoretically divided to intiation step and promotion step. Intiation associates with genetic alterations including p53 tumor suppressor gene and ras oncogene. Promotion involves in clonal expansion of of an initiated cell by epigenetic mechanism, mainly through signal transduction and gene expression. Ultraviolet light (UV) acts as both initiator and promoter. Initiation is closely related with DNA damage induced by UV, including cyclobutane pyrimidine dimers, (6-4) photoproducts and 8-hydroxy-2'-deoxyguanosine. Cyclobutane pyrimidine dimers and (6-4) photoproducts are directly induced by UV, while 8-hydroxy-2'-deoxyguanosine is induced indirectly by the reactive oxygen species. Because initiation is an irreversal genetic event, while promotion is a reversal and epigenetic event, to know the molecular mechanisms of tumor promotion in UV-carcinogenesis is crucial to develop preventive medicine and suppress UV-carcinogenesis. Because ROS is also involved in signal transduction of the cell, anti-oxidant could be the good candidate of anti-promoting agent. Here, we describe the suppressive effect of UV-carcinogenesis by various anti-oxidant including olive oil. In addition, we discuss about the mechanism of UVB-induced expression of cyclooxygenase-2, which might be a representative molecule involved in promotion of UV-carcinogenesis.

• Journal of Life Science
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• v.30 no.1
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• pp.88-95
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• 2020

Using a random arbitrarily primed polymerase chain reaction, messenger RNA expression levels were assessed after exposure to 10% (v/v) toluene for 8 hr in solvent-tolerant Pseudomonas sp. BCNU 106. Among the 100 up-expressed products, 50 complementary DNA fragments were confirmed to express repeatedly; these were cloned and then sequenced. Blast analysis revealed that toluene stimulated an adaptive increase in the gene expression level in association with transcriptions such as LysR family of transcriptional regulators and RNA polymerase factor sigma-32. The expression of catalase and Mn2+/Fe2+ transporter genes functionally associated with inorganic ion transport and metabolism increased, and the increased expression of type IV pilus assembly PilZ and multi-sensor signal transduction histidine kinase genes, functionally categorized into signal transduction and mechanisms, was also demonstrated under toluene stress. The gene expression level of beta-hexosaminidase in association with carbohydrate transport and metabolism increased, and those of DNA polymerase III subunit epsilon, DNA-3-methyladenine glycosylase II, DEAD/DEAH box helicase domain-containing protein, and ABC transporter also increased after exposure to toluene in DNA replication, recombination, and repair, and even in defense mechanism. In particular, the RNAs corresponding to the ABC transporter, Mn2+/Fe2+ transporter, and the β-hexosaminidase gene were confirmed to be markedly induced in the presence of 10% toluene. Thus, defense mechanism, cellular ion homeostasis, and biofilm formation were shown as essential for toluene tolerance in Pseudomonas sp. BCNU 106.

• Molecules and Cells
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• v.26 no.5
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• pp.462-467
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• 2008

TPA is known to cooperate with an activated Ras oncogene in the transformation of rodent fibroblasts, but the biochemical mechanisms responsible for this effect have not been established. In the present study we used c-fos promoter-luciferase constructs as reporters, in transient transfection assays, in NIH3T3 cells to assess the mechanism of this cooperation. We found a marked synergistic interaction between TPA and a transfected v-Ha-ras oncogene in the activation of c-fos promoter and SRE. SRE has binding sites for TCF and SRF. A dominant-negative Ras (ras-N17) inhibited the TPA-Ras synergy by blocking the PKC-MAPK-TCF pathway. Dominant-negative RhoA and Rac1 (but not Cdc42Hs) inhibited the TPA-Ras synergy by blocking the Ras-Rho-SRF signaling pathway. Constitutively active $PKC{\alpha}$ and $PKC{\varepsilon}$ showed synergy with v-Ras. These results suggest that the activation of two distinct pathways such as Ras-Raf-ERK-TCF pathway and Rho-SRF pathway are responsible for the induction of c-fos by TPA and Ras in mitogenic signaling pathways.

• Natural Product Sciences
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• v.15 no.3
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• pp.156-161
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• 2009

Rubus coreanus, commonly known as 'red raspberry' is used as a traditional oriental medicine in Korea for the management of diseases such as impotence, spermatorrhea and athsma, and for allergies, in combination with other herbal preparations, in many centuries. We undertook a comparison of the hepatoprotective effect of ethanol extracts of the unripe (UREx) and ripe (RREx) R. coreanus extract against acetaminophen (AAP) induced hepatotoxicity in rats. UREx reduced the elevated alanine aminotransferase (ALP), aspartate aminotransferase (AST), total bilirubin (TB), alkaline phosphatase (AP), lipid peroxide and nitric oxide content which had been increased by AAP administration. UREx also increased the cellular glutathione (GSH) content and induced the glutathione-S-transferase (GST), glutathione peroxidase (GSH-Px) content which had been decreased by AAP. RREx did not exhibit strong hepatoprotective effect or antioxidant activity under the same conditions. The experimental results show that the degree of the ripening of R. coreanus affects the hepatoprotective activity in the AAP-intoxicated rats. These findings of a protective mechanism are supportive evidence for the utility of unripened R. coreanus in traditional medicine for liver ailments.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.56-56
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• 1993

새로운 cell cycle 특이적 억제제의 스크리닝 방법의 확립과 이를 이용하여 cell cycle 억제제의 검색 및 세포분열 및 성장을 억제하는 작용의 분석과 이들의 항암작용 및 세포성장 및 분열 억제 작용의 signal transduction mechanism을 규명한다. 이상의 연구를 수행하기 위해 흰쥐 재생간 조직 및 흰쥐 일차 배양 간세포를 연구 모델로 하여 스크리닝 방법을 확립하고, 세포 분열 및 성장 억제제의 연구 대상 약물로는 기존의 천연물 및 미생물의 2차 대사 산물을 분리 정제한 물질등을 사용하여 그 작용 효능을 연구한다. 1) 흰쥐 부분 간 절제 수술 26시간 후 핵 단백질을 분리 2) MPF activity 측정 3) MPF 활성 저해제 생산 균주의 1차 탐색

• Proceedings of the Korean Biophysical Society Conference
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• 1997.07a
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• pp.15-15
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• 1997

Recent studies indicate that hydrogen peroxide (H$_2$O$_2$), which is one of the reactive oxygen species involved in the oxidative stress, is an intracellular secondary messenger in the signal transduction. A novel family of thiol specific antioxidant (TSA) enzymes with a peroxidase activity shows no sequence homology to previously known antioxidant enzymes.(omitted)

• BMB Reports
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• v.45 no.12
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• pp.693-699
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• 2012

Together with protein tyrosine kinases (PTKs), protein tyrosine phosphatases (PTPs) serve as hallmarks in cellular signal transduction by controlling the reversible phosphorylation of their substrates. The human genome is estimated to encode more than 100 PTPs, which can be divided into eleven sub-groups according to their structural and functional characteristics. All the crystal structures of catalytic domains of sub-groups have been elucidated, enabling us to understand their precise catalytic mechanism and to compare their structures across all sub-groups. In this review, I describe the structure and mechanism of catalytic domains of PTPs in the structural context.

• The Journal of Pediatrics of Korean Medicine
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• v.28 no.3
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• pp.31-46
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• 2014

Objectives Forsythiae Fructus treatment has been used for inflammatory and allergic diseases in Korean Medicine. Nevertheless, the mechanism of action and the cellular targets are not understood well. The pathogenesis of allergic diseases are associated with Th2 cytokines such as IL-13, MIP-$1{\alpha}$, IL-13, IL-5, GM-CSF, IL-4, TNF-${\alpha}$ and IL-6, which are secreted by the mast cells. This study was conducted to investigate the effects of Forsythiae Fructus extracts (FF) on Th2 cytokines expression and signal transduction in MC/9 mast cells. Methods In the study, MC/9 mast cells were stimulated with DNP-IgE for 24 hours and then treated separately with CsA $10{\mu}g/m{\ell}$ and varying doses of FF for one hour. MC/9 mast cells stimulated with DNP-IgE was the control group, a treatment with CsA was the positive control group and a treatment with varying doses FF was the experimental groups. The mRNA levels of IL-13, IL-5, GM-CSF, IL-4, TNF-${\alpha}$, IL-6 were analyzed with Real-time PCR. The levels of IL-13, MIP-$1{\alpha}$ were measured using enzyme-linked immunosorbent assays(ELISA). NFAT, AP-1 and NF-${\kappa}B$ p65 were examined by Western blot analysis. Results 1. FF were observed to suppress the mRNA expression of IL-13, IL-5, GM-CSF, IL-4, TNF-${\alpha}$, IL-6 in comparison to DNP-IgE control group. 2. FF also has inhibited the IL-13, MIP-$1{\alpha}$ production significantly in comparison to DNP-IgE control group. 3. Western blot analysis of transduction factors involving Th2 cytokines expression has revealed a prominent decrease of the mast cell specific transduction factors including NFAT-1, NFAT-2, c-Jun, and NF-${\kappa}B$ p65 but c-Fos. Conclusions In conclusion, the anti-allergenic activities of FF may be strongly related to the regulation of transcription factors NFAT-1, NFAT-2, c-Jun, and NF-${\kappa}B$ p65 causing inhibition of Th2 cytokines in mast cells.

• The Journal of the Korea Contents Association
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• v.9 no.4
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• pp.355-363
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• 2009

Increased oxidative stress by abnormal mitochondrial function can damage cell signal transduction and gene expression, and induce insulin resistance or diabetes. Autophagy, however, improve insulin resistance by clearance of malfunctioning mitochondria. Exercise also recovers the muscle dysfunction and degeneration by activating mitochondrial biogenesis. As it seems that exercise and autophagy might act as an orchestrated network to induce mitochondrial biogenesis, we investigated whether autophagy is involved in AMPK signal pathway stimulated by exercise or AICAR to increase mitochondrial biogenesis. And it showed that PGC-1 and mtTFA, but not autophagy marker LC3 mRNA expression were significantly increased by 6 hr of acute exercise. On the other hand, PGC-1 and mtTFA mRNA expression were upregulated by AICAR treatment to C2C12 myotube. However these genes were not inhibited by LC3 siRNA transfection. These results provide the evidence that autopahgy affects on mitochondrial biogenesis through different signal pathway from AMPK signal transduction.

• Journal of Ginseng Research
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• v.32 no.1
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• pp.1-7
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• 2008

Ginseng saponin has been shown to inhibit the development of dependence on morphine, cocaine, methamphetamine, but the antinarcotics effects of ginseng on nalbuphine remains still largely unknown. Ginseng administration attenuated the naloxone-induced jumping behavior on nalbuphine dependent mice. The development of morphine dependence was mediated through ${\mu}-opioid$ receptor, however, development of nalbuphine dependence was mediated through ${\kappa}-opioid$ receptor. However, it was found that the efficacy of analgesic antagonism of GTS was mediated through the serotonergic mechanism, not mediated through the opioid receptor. In addition, ginseng administration modulated cellular signal transduction in the brain. The increased NMDA receptor subunit (NR1, pNR1), phosphate extracellular signal regulated protein kinase (pERK), phosphate cAMP response element binding protein (pCREB) expression by nalbuphine was decreased by the administration of ginseng powder in cortex, hippocampus, striatum of rat brain. These results suggest that ginseng could be one of the targets of antinarcotic therapies to reduce the development of tolerance and dependence on nalbuphine as well as morphine.