• Korean Journal of Clinical Laboratory Science
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• v.50 no.3
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• pp.337-344
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• 2018

Hepatocellular carcinoma (HCC), a major type of hepatoma, is associated with high recurrence and mortality because of its uncontrolled metastatic feature. Silymarin is a polyphenolic flavonoid from Silybum marianun (milk thistle) and exhibits anti-carcinogenic activity through modulation of the epithelial-mesenchymal transition (EMT) in several cancer cells. In this study, the inhibitory mechanism of silymarin against migration and invasion was investigated in the Huh7 HCC cell line. Wound healing and in vitro invasion assays were conducted to examine the effects of silymarin on migration and invasion. Western blot analysis was also applied to evaluate the inhibitory effects of silymarin on the EMT-related genes and their upstream signaling molecules. Silymarin inhibited the migratory and invasive activities of Huh7 cells. In addition, silymarin attenuated the protein expression levels of vimentin and matrix metalloproteinase (MMP)-9 as well as their transcription factors, Snail, and nuclear factor $(NF)-{\kappa}B$, while the expression of E-cadherin was increased by the silymarin treatment. Among the upstream signaling molecules, the phosphorylation of Akt was inhibited by the silymarin treatment, which was confirmed by the selective inhibitor, LY294002. Consequently, silymarin inhibited the invasive and migratory activities in Huh7 cells through the modulation of EMT-related gene expression by the PI3K/Akt signaling pathway, which may have potential as a chemopreventive agent against HCC metastasis.

• Journal of The Korean Society of Integrative Medicine
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• v.11 no.3
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• pp.59-67
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• 2023

Purpose : Epithelial-to-mesenchymal transition (EMT) is recognized as an important cellular response in metastatic proceduresand characterized by loss of cellular polarity as well as gain of mesenchymal features, which enables migration and invasion. Hepatocellular carcinoma (HCC) is one of the most common primary carcinomas in the liver and exhibits a poor prognosis due to frequent extrahepatic metastasis. Taraxacum officinale has been used for a long time in oriental medicine because of its various pharmacological activitiessuch as anti-rheumatic, anti-inflammatory, antioxidative, and anticarcinogenic activities. In this study, the anti-metastatic activity of T. officinale water extract (TOWE) and ethanol extract (TOEE) was investigated through the regulation of EMT in the Huh7 cells. Methods : The effects of TOWE and TOEE on migratory and invasive activities were investigated by wound healing and in vitro invasion assays. Western blot analysis was also applied to analyze protein expression levels associated with EMT and their upstream transcription factors in Huh7 cells. Results : TOWE and TOEE treatment potently inhibited migration and invasion of Huh7 cells compared to the untreated group. Both extracts treatment inhibited protein expression levels of N-cadherin, matrix metalloproteinase (MMP)-9, and vimentin while E-cadherin was significantly accelerated. In addition, the activated status of transcription factors, Snail, nuclear factor (NF)-κ B, and zinc finger E-box binding homeobox (ZEB)1 was also inhibited with statistical significance. In comparison to both extracts, TOEE more potently attenuated migration, invasion, and EMT markers as well as their transcription factors in Huh7 cells than TOWE, which means that TOEE might possess more functional phytochemicals than TOWE. Conclusion : Consequently, TOWE and TOEEattenuated metastatic activity of hepatocellular carcinoma through the regulation of EMT markers and their transcription factors in Huh7 cells, which means that T. officinale might be a promising strategy for a chemopreventive agent against HCC metastasis.

• Ecology and Resilient Infrastructure
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• v.1 no.2
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• pp.68-81
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• 2014

In this study, the numerical simulation regarding the process and characteristics of topography change due to the vegetation recruitment and growth was carried out by adding the vegetation growth model to two-dimensional flow and sediment transport models. The vegetation introduction and recruitment on the condition for developing an alternate bar reduced the bar migration. The vegetated area and channel width changes were more significantly influenced by changes in upstream discharge rather than the duration of low flow. When the upstream discharge decreased, the vegetation area increased and the channel width decreased. The vegetation introduction and recruitment on the condition for developing a braided channel significantly influenced the characteristics of topography changes. In the braided channel, vegetation reduced the braided index, and when the upstream discharge decreased significantly, the channel topography was changed from the braided channel to the single channel. The vegetation area decreased as the upstream discharge increased. The channel width decreased significantly after the vegetation was introduced and it also decreased as the upstream discharge decreased. It was confirmed through the numerical simulation that a decrease in flood discharge accelerated the vegetation introduction and recruitment in the channel and this allowed to confirm its influence on the characteristics of topography changes qualitatively.

• Journal of The Geomorphological Association of Korea
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• v.26 no.3
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• pp.43-52
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• 2019

Place names or toponyms including Gosan, Busan and Buraesan can be very important and interesting storytelling subjects in terms of geomorphology and folklore studies also. Several studies done by folklorists, those sixty five mountain-moving stories with similar names can be grouped into several categories through formation processes and origin, transport media and imposition of tax. Geomorphological studies can focus on transport media. They can be classified into six different categories; 1) flood from upstream through river, 2) voluntary walk of mountains, 3) by wind, 4) upwelling from underground, 5) involvement of mythical beings such as Mago Granny or Dokkaebi (kind of goblin), or 6) migration by ocean current.

• Korean Journal of Ecology and Environment
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• v.44 no.4
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• pp.385-395
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• 2011

The adjustment processes and responses of a series of mining pits by sand or gravel mining were investigated by laboratory experiments. The filling processes of the two pits were affected by the bars developed in the upstream of the channel. However, the bars were not developed and the bed was degradated in the downstream of the pits due to little sediment flow, which was trapped in the pits. The submerged angle of repose in the pits was nearly constant when the pits were being filled. After the filling processes of the pits were finished, the pit was speedily filled with sediment, and the bed was aggradated and migrated with speed. However, the angle of repose decreased. As the distance between the upstream pit and the downstream pit increased, the bed of the pit downstream was tailcutted and degradated. The migration speed of the pit decreased. However, the dimensionless pit depth increased as the distance between the pits increased. The dimensionless pit depth increased with time.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.2
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• pp.416-425
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• 2009

Angiogenesis is important for promoting cardiovascular disease, wound healing, and tissue regeneration. We here investigated the pharmacological effects of Korea red ginseng water extract (KRGE) on angiogenesis and its underlying signal mechanism. This study showed that KRGE increased in vitro proliferation, migration, and tube formation of human umbilical endothelial cells, as well as stimulated in vivo angiogenesis. KRGE-induced angiogenesis was accompanied by phosphorylation of ERK1/2, Akt, and endothelial nitric oxide synthase (eNOS) as well as an increase in NO production. Inhibition of PI3K activity by wortmannin completely inhibited KRGE-induced angiogenesis and phosphorylation of Akt, ERK1/2, and eNOS, indicating that PI3K/Akt activation is an upstream event of KRGE-mediated angiogenic pathway. The MEK inhibitor PD98059 completely blocked KRGE-induced angiogenesis and ERK phosphorylation without affecting Akt and eNOS activation. However, the eNOS inhibitor NMA effectively inhibited tube formation, but partially blocked proliferation and migration as well as ERK phosphorylation without altering Akt and eNOS activation, revealing that eNOS/NO pathway is in part involved in ERK1/2 activation. This study first demonstrated the critical involvement of both ERK1/2 and eNOS activation in KRGE-induced angiogenesis, which lie on downstream of PI3K/Akt. Thus, these results indicate that KRGE requires activation of both the PI3K/Akt-dependent ERK1/2 and eNOS signal pathways and their cross-talk for its full angiogenic activity.

• BMB Reports
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• v.52 no.12
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• pp.706-711
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• 2019

Cisplatin (Cis-DDP) is one of the most widely used anti-cancer drugs. It is applicable to many types of cancer, including lung, bladder, and breast cancer. However, its use is now limited because of drug resistance. p90 ribosomal S6 kinase (p90RSK) is one of the downstream effectors in the extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) pathway and high expression of p90RSK is observed in human breast cancer tissues. Therefore, we investigated the role of p90RSK in the Cis-DDP resistance-related signaling pathway and epithelial-mesenchymal transition (EMT) in breast cancer cells. First, we discovered that MDA-MB-231 cells exhibited more Cis-DDP resistance than other breast cancer cells, including MCF-7 and BT549 cells. Cis-DDP increased p90RSK activation, whereas the inactivation of p90RSK using a small interfering RNA (siRNA) or dominant-negative kinase mutant plasmid overexpression significantly reduced Cis-DDP-induced cell proliferation and migration via the inhibition of matrix metallopeptidase (MMP)2 and MMP9 in MDA-MB-231 cells. In addition, p90RSK activation was involved in EMT via the upregulation of mRNA expression, including that of Snail, Twist, ZEB1, N-cadherin, and vimentin. We also investigated NF-κB, the upstream regulator of EMT markers, and discovered that Cis-DDP treatment led to NF-κB translocation in the nucleus as well as its promoter activity. Our results suggest that targeting p90RSK would be a good strategy to increase Cis-DDP sensitivity in triple-negative breast cancers.

• Journal of Korea Water Resources Association
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• v.54 no.8
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• pp.629-641
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• 2021

In this study, a two-dimensional numerical model (Nays2DH) was applied to analyze the process of morphological changes in the river channel bed depending on the changes in the amount of flooding after fully opening the Sejong weir, which was constructed upstream of the Geum River. For this, numerical simulations were performed by assuming the flow conditions, such as a non-uniform flow (NF), unsteady flows (single flood event, SF), and a continuous flood event (CF). Here, in the cases of the SF and CF, the normalized hydrograph was calculated from real flood events, and then the hydrograph was reconfigured by the peak flow discharge according to the scenario, and then it was employed as the flow discharge at the upstream boundary condition. In this study, to quantitatively evaluate the morphological changes, we analyzed the time changes in the bed deformation the bed relief index (BRI), and we compared the aerial photographs of the study area and the numerical simulation results. As simulation results of the NF, when the steady flow discharge increases, the ratio of lower width to depth decreases and the speed of bar migration increases. The BRI initially increases, but the amount of change decreased with time. In addition, when the steady flow discharge increases, the BRI increased. In the case of SF, the speed of bar migration decreased with the change of the flow discharge. In terms of the morphological response to the peak flood discharge, the time lag also indicated. In other words, in the SF, the change of channel bed indicates a phase lag with respect to the hydraulic condition. In the result of numerical simulation of CF, the speed of bar migration depending on the peak flood discharges decreased exponentially despite the repeated flood occurrences. In addition, as in the result of SF, the phase lag indicated, and the speed of bar migration decreased exponentially. The BRI increased with time changes, but the rate of increase in the BRI was modest despite the continuous peak flooding. Through this study, the morphological changes based on the hydrological characteristics of the river were analyzed numerically, and the methodology suggested that a quantitative prediction for the river bed change according to the flow characteristic can be applied to the field.

• Korean Journal of Ichthyology
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• v.20 no.3
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• pp.210-219
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• 2008

Monthly variation in species composition of upstream-migrating fish in the Cheonjeyeon Estuary was determined by analyzing fish data collected January~September 2004 and January~August 2007. Fish migrating from the sea to freshwater through the channels were collected by a rectangular net with a mesh size of 2 mm during the day and at night in the new moon. Of 14 species collected, ayu (Plecoglossus altivelis altivelis) and mullet (Mugil cephalus) predominated in abundance. Glass eels (Anguilla japonica) occurred mainly during the night from February to May. Other fishes collected included brackish-water gobiids (Gymnogobius urotaenia, Rhinogobius giurinus, Tridentiger obscurus, and Sicyopterus japonicus), freshwater fishes (Misgurnus anguillicaudatus and Rhynchocypris oxycephalus), and coastal marine fishes (Engraulis japonicus, Pempheris japonica, Plotosus lineatus, Takifugu niphobles, and Terapon jarbua). Ayu occurred during almost all sampling periods. They ranged principally from 55 to 100 mm total length (TL), with some fish larger than 100 mm TL collected after April. Mullet also occurred during almost all sampling periods. They ranged principally 25~58 mm TL, with some larger fish of 103~240 mm TL collected in February and April. That only a few freshwater and brackish-water fishes occurred in the study area is probably related to the freshwater systems having long been isolated from the continental systems and to the poorly developed estuaries in Jeju Island reflecting limited river discharge.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11a
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• pp.198-203
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• 2003

The effects of salmon carcasses on forest and stream ecosystems were determined by nitrogen stable isotope analysis in natural streams in Hokkaido, Northern Japan, where numerous chum salmon (Oncoryhncus keta) were migrated upstream ITom ocean to spawn in autumn. The leaves and soils surrounding riparian forest and stream dwelling invertebrates were collected before and after migration. The nitrogen stable isotope ratio $({\delta}^{15}N)$ of riparian vegetation (Salix spp.) were different depending on the presence of salmon and distance from the stream. The $({\delta}^{15}N)$ of stream dwelling invertebrates were different between salmon present and absent stream. This difference was tested using the experiment channel by implanting salmon carcasses. The nitrogen stable isotope ratio of epilithic algae and leaf shredding animals were nearly 3 higher in the salmon implanted treatment suggesting that around 20％ of salmon derived nitrogen was uptake either in algae and leaf shredding invertebrates. These results suggest that the salmon carcasses effects not only on stream primary production but also on primary consumers, which decompose leaves fertilized with nitrogen from carcasses.