• Natural Product Sciences
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• 제28권2호
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• pp.80-88
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• 2022

Colorectal cancer is one of the most common cancers globally, ranking second for the number of cancer-related deaths. Metastasis has been reported as the main cause of death in patients with colorectal cancer. Peroxisome proliferator-activated receptor gamma (PPAR-γ) is a transcription factor that functions as a tumor suppressor by inhibiting cellular proliferation, migration, and invasion. In our previous efforts to generate natural product-motivated PPAR-γ ligands, the compounds 1 and 2 were obtained. These compounds activated PPAR-γ and inhibited the migration and invasion of HCT116 colorectal cancer cells, and they were also found to inhibit the epithelial-to-mesenchymal transition, which is a key process in cancer metastasis. Compounds 1 and 2 upregulated expression of the epithelial marker (E-cadherin), and downregulated expression of the mesenchymal marker (N-cadherin) and transcriptional factor (Snail). Therefore, the PPAR-γ agonists 1 and 2 could serve as a valuable model for the study on anti-metastatic leads for the treatment of colorectal cancer.

• Toxicological Research
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• 제26권4호
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• pp.245-252
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• 2010

Epithelial-mesenchymal transition (EMT) is a complex process in which epithelial cells acquire the characteristics of invasive mesenchymal cells. EMT has been implicated in cancer progression and metastasis as well as the formation of many tissues and organs during development. Epithelial cells undergoing EMT lose cell-cell adhesion structures and polarity, and rearrange their cytoskeletons. Several oncogenic pathways such as transforming growth factor (TGF)-$\beta$, Wnt, and Notch signaling pathways, have been shown to induce EMT. These pathways have activated transcription factors including Snail, Slug, and the ZEB family which work as transcriptional repressors of E-cadherin, thereby making epithelial cells motile and resistant to apoptosis. Mounting evidence shows that EMT is associated with cell invasion and tumor progression. In this review, we summarize the characteristic features of EMT, pathways leading to EMT, and the role of EMT in cell invasion. Three topics are addressed in this review: (1) Definition of EMT, (2) Signaling pathways leading to EMT, (3) Role of EMT in cell invasion. Understanding the role of EMT in cell invasion will provide valuable information for establishing strategies to develop anti-metastatic therapeutics which modulate malignant cellular processes mediated by EMT.

• Asian Pacific Journal of Cancer Prevention
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• 제16권15호
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• pp.6201-6206
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• 2015

The epithelial-mesenchymal transition (EMT) is a cellular process though which an epithelial phenotype can be converted into a phenotype of mesenchymal cells. Under physiological conditions EMT is important for embryogenesis, organ development, wound repair and tissue remodeling. However, EMT may also be activated under pathologic conditions, especially in carcinogenesis and metastatic progression. Major signaling pathways involved in EMT include transforming growth factor ${\beta}(TGF-{\beta})$, Wnt, Notch, Hedgehog and other signaling pathways. These pathways are related to several transcription factors, including Twist, Smads and zinc finger proteins snail and slug. These interact with each other to provide crosstalk between the relevant signaling pathways. This review lays emphasis on studying the relationship between EMT and signaling pathways in carcinogenesis and metastatic progression.

• Biomolecules & Therapeutics
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• 제28권5호
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• pp.405-413
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• 2020

Fibroblast-like synoviocytes (FLS) play a crucial role in initiating rheumatoid arthritis. B-cell activating factor (BAFF) plays a role in FLS survival as well as in B cell maturation and maintenance. Here, we investigated whether tumor necrosis factor (TNF)-α-induced BAFF expression controls FLS migration and whether BAFF expression in FLS could be regulated by KR33426 which is the inhibitor of BAFF binding to BAFF receptors (BAFF-R) by using MH7A synovial cells transfected with the SV40 T antigen. More TNF-α-treated cells migrated compared to the control. TNF-α increased BAFF expression in FLS, significantly. FLS migration was inhibited by the transfection with BAFF-siRNA. KR33426 also inhibited BAFF expression increased by TNF-α treatment in FLS as judged by western blotting, PCR, and transcriptional activity assay. Kinases including JNK, p38 and Erk were activated by TNF-α treatment. While JNK and p38 were inhibited by KR33426 treatment, no changes in Erk were observed. Transcription factors including p65, c-Fos, CREB and SP1 were enhanced by TNF-α treatment. Among them, c-Fos was inhibited by KR33426 treatment. Small interference(si)-RNA of c-fos decreased BAFF transcriptional activity. FLS migration induced by TNF-α was inhibited by the transfection with BAFF-siRNA. KR33426 increased Twist, Snail, Cadherin-11 and N-Cadherin. In contrast, KR33426 decreased E-cadherin and TNF-α-enhanced CCL2. Taken together, our results demonstrate that synovial cell migration via CCL2 expression could be regulated by BAFF expression which is decreased by KR33426 and c-Fos-siRNA. It suggests for the first time that the role of BAFF-siRNA on FLS migration might be matched in the effect of KR33426 on BAFF expression.

• Preventive Nutrition and Food Science
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• 제8권3호
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• pp.239-244
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• 2003

Recently, we reported (J Korean Soc Food Sci Nutr, 31(3): 516-520, 2002) that Semisulcospira libertina (Marsh Snail) pretreatment has a hepatoprotective effect on $CCl_4$-induced liver damage in rats. The purpose of this study was to investigate the possible mechanisms of hepatoprotection by S. libertina (SL) on liver injury induced by acetaminophen (AA). Male ICR mice were pretreated with dehydrated powder of SL once daily for three consecutive days, given a single toxic dose of AA (450 mg/kg) and liver function determined 24 h later. Liver damage was assessed by quantifying serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and sorbitol dehydrogenase (SDH) activities, and by measuring hepatic lipid peroxidation. To confirm possible mechanism(s), the content of hepatic glutathione (GSH) and gene expression of tumor necrosis factor a (TNF $\alpha$) mRNA by reverse transcription-polymerase chain reaction (RTPCR) were also measured. Pretreatment with SL dramatically lowered AA-elevated ALT, AST and SDH activities. SL pretreatment decreased AA-produced lipid peroxidation by 11% and restored the AA-depleted hepatic GSH by 27%. Furthermore, SL markedly suppressed the expression of TNF $\alpha$ mRNA induced by AA. Our findings revealed that the possible hepatoprotective mechanisms of SL could be attributed, at least in part, to the glutathione-mediated detoxification as well as the regulation of TNF $\alpha$ mRNA expression.

• 한국식품과학회지
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• 제50권1호
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• pp.105-110
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• 2018

멜리틴은 봉독의 주요 성분 중 하나로 항염증과 항암활성 효과를 가지고 있다. 우리는 폐암세포에서 멜리틴이 EMT 억제를 통해 암세포 이동과 침투를 억제하는 사실을 확인하였다. 멜리틴은 EGF로 유도된 폐암 세포 이동과 침투를 억제하였을 뿐만 아니라 EMT와 관련된 단백질인 이카드헤린의 발현을 증가시켰으며, 바이멘틴과 피브로넥틴 발현은 감소시켰다. 또한 멜리틴에 의한 EMT조절 전사인자인 ZEB2, Slug, Snail의 발현을 확인한 결과 멜리틴 처리에 의해 농도의존적으로 발현이 감소하였다. 또한 작용 메커니즘을 확인하기 위해 mTOR와 FAK 메커니즘을 확인한 실험에서 EGF 처리에 의해 증가한 AKT, mTOR, p70S6K, 4EBP1의 인산화가 멜리틴 농도의존적으로 감소하였다. 그러나 FAK는 EGF에 의해 변화가 없었으며, EKR, JNK 메커니즘은 EGF 처리에 의해 인산화가 증가하였으나 멜리틴 처리에 의해 아무런 영향을 받지 않았다. 그러므로, 폐암세포의 세포 이동과 침투에 대한 멜리틴의 억제효과는 AKT/mTOR/P70S6K/4EBP1 기전 억제를 통해 EMT를 억제하여 세포 이동과 침투를 억제하는 것으로 보인다.

• 한국식품영양과학회지
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• 제42권8호
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• pp.1167-1174
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• 2013

암세포를 포함한 생체 내 빠른 분열을 요구하는 세포 집단에서 세포 내 구성요소 및 에너지원으로서 글루타민의 요구량이 증대되지만, 종양세포의 글루타민 의존적 대사작용에 관한 기전은 여전히 잘 알려진 바 없다. 본 연구에서는 LnCaP 전립선 암세포의 이동성 및 침윤성에 미치는 글루타민 결핍효능을 조사하였다. 본 연구의 결과에 의하면 LnCaP 세포에서 글루타민 결핍에 의하여 세포의 이동성 및 세포의 침윤성이 현저하게 억제되었으며, 이러한 이동성 및 침윤성 억제는 TIMPs의 발현 증대에 의한 MMPs의 발현 감소 및 그들의 효소적 활성 저하와 연관성이 있었다. 또한 글루타민이 결핍된 조건에서 배양된 LnCaP 세포에서 TER의 현저한 증가가 관찰되었는데, 이는 TJs의 조절인자인 claudin family 발현의 차단에 의한 것으로 생각되어진다. 본 연구의 결과에 의하면 암세포의 증식에서 글루타민의 결핍은 TJ의 결합력 증대와 MMPs의 활성을 저하시킴으로써 암세포 전이에 가장 기본적인 과정인 암세포의 이동성과 침윤성을 억제시킬 수 있을 것으로 생각된다.

• BMB Reports
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• 제52권10호
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• pp.595-600
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• 2019

Cardiac fibrosis is a common feature in chronic hypertension patients with advanced heart failure, and endothelial-to-mesenchymal transition (EndMT) is known to promote Angiotensin II (Ang II)-mediated cardiac fibrosis. Previous studies have suggested a potential role for the transcription factor, ETS-1, in Ang II-mediated cardiac remodeling, however the mechanism are not well defined. In this study, we found that mice with endothelial Ets-1 deletion showed reduced cardiac fibrosis and hypertrophy following Ang II infusion. The reduced cardiac fibrosis was accompanied by decreased expression of fibrotic matrix genes, reduced EndMT with decreased Snail, Slug, Twist, and ZEB1 expression, as well as reduced cardiac hypertrophy and expression of hypertrophy-associated genes was observed. In vitro studies using cultured H5V cells further confirmed that ETS-1 knockdown inhibited $TGF-{\beta}1$-induced EndMT. This study revealed that deletion of endothelial Ets-1 attenuated Ang II-induced cardiac fibrosis via inhibition of EndMT, indicating an important ETS-1 function in mediating EndMT. Inhibition of ETS-1 could be a potential therapeutic strategy for treatment of heart failure secondary to chronic hypertension.