• Toxicological Research
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• v.26 no.4
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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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• v.16 no.15
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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.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.3681-3685
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• 2012

Background: In breast cancer, estrogen receptors have been demonstrated to interact with transcription factors to regulate target gene expression. However, high-throughput identification of the transcription regulation relationship between transcription factors and their target genes in response to estradiol is still in its infancy. Purpose: Thus, the objective of our study was to interpret the transcription regulation network of MCF7 breast cancer cells exposed to estradiol. Methods: In this work, GSE11352 microarray data were used to identify differentially expressed genes (DEGs). Results: Our results showed that the MYB (v-myb myeloblastosis viral oncogene homolog [avian]), PGR (progesterone receptor), and MYC (v-myc myelocytomatosis viral oncogene homolog [avian]) were hub nodes in our transcriptome network, which may interact with ER and, in turn, regulate target gene expression. MYB can up-regulate MCM3 (minichromosome maintenance 3) and MCM7 expression; PGR can suppress BCL2 (B-cell lymphoma 2) expression; MYC can inhibit TGFB2 (transforming growth factor, beta 2) expression. These genes are associated with breast cancer progression via cell cycling and the $TGF{\beta}$ signaling pathway. Conclusion: Analysis of transcriptional regulation may provide a better understanding of molecular mechanisms and clues to potential therapeutic targets in the treatment of breast cancer.

• Food Science of Animal Resources
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• v.32 no.5
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• pp.635-643
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• 2012

As an appraisal for the application of a new starter culture, more than 200 lactic acid bacteria strains were isolated from raw milk and healthy human feces. The strains showing excellent growth and acid production ability in 10% skim milk media were selected and identified as Lactobacillus casei based on the results of their API carbohydrate fermentation patterns, as well as 16S rDNA sequence analysis. To assess the effect of L. casei strains on irritable bowel disease (IBD), the inhibitory effect of the selected strains against the nitric oxide (NO) production of lipopolysaccharide (LPS)-stimulated RAW 264.7 cells was measured. Among the tested L. casei strains, L. casei MCL was observed to have the greatest NO inhibitory activity. Additionally, L. casei MCL was found to inhibit mRNA expression of pro-inflammatory cytokines (interleukin-$1{\beta}$, IL-6, TNF-${\alpha}$), as well as cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) involved in pathophysiologic processes such as inflammation. The mRNA expression of anti-inflammatory cytokines, including IL-10 and transforming growth factor-$1{\beta}$ (TGF-${\beta}$) of L. casei MCL, was confirmed using quantitative real-time PCR. In conclusion, L. casei MCL showed decreases in the expression of pro-inflammatory cytokines and up-regulated expression of the anti-inflammatory cytokine.

• Biomedical Science Letters
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• v.19 no.3
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• pp.195-205
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• 2013

Obesity may cause metabolic syndrome and adult diseases. This study was undertaken to investigate the ameliorative or useful effects of beanleaves on inflammation and liver damage in obese rat models. Rats were divided into three groups: a control group (normal diet, n=6), a fat diet group (45%-fat diet, n=7), and a bean leaf group (45%-fat+Korean bean leaves diet, n=7). Body weights in the bean leaf group were lower than those of the fat group (P<0.05). Serum tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and prostaglandin $E_2$ ($PGE_2$) concentrations were lower in both the control and bean leaf groups than in the fat group (P<0.001). TNF-${\alpha}$ concentrations in the bean leaf group were slightly higher than in the control group but statistically significant (P<0.05). The bean leaf group histologically exhibited lower fatty degeneration, spotty necrosis, and leukocyte infiltrations in hepatic tissues than those of the fat group. In the homogenized liver tissues, the cyclooxygenase-2 (COX-2) gene was only expressed in the fat group. The gene expression levels of hepatic TNF-${\alpha}$, inducible nitric-oxide synthase, peroxiome proliferator-activated receptor-${\alpha}$ (PPAR-${\alpha}$), poly (ADP-ribose) polymerase (PARP), and transforming growth factor-${\beta}1$ (TGF-${\beta}1$) were weaker in the bean leaf group than in the fat group. These results suggest that adding bean-leaves to the diet may ameliorate obesity-induced systemic inflammation and liver damage and that bean leaves may be a useful food for preventing obesity and thereby metabolic syndrome and adult diseases.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.7
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• pp.929-937
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• 2016

The purpose of this study was to investigate the effect of Acanthopanax senticosus extract (ASE) (ethanol : DW=1:1, v/v) on inhibition of type 2 diabetes using an OLETF rat model via regulation of HbA1c and AGEs levels. Supplementation with ASE 0.1% and 0.5% effectively lowered levels of glucose, insulin, oral glucose tolerance test, and Homa-insulin resistance, suggesting reduced insulin resistance. Blood levels of HbA1c and AGEs were significantly reduced in a dose-dependent manner. As oxidative stress plays a key role in accelerating production of HbA1c and AGEs, which worsen symptoms of type 2 diabetes, levels of malonaldehyde and pro-inflammatory cytokines were measured. Lipid peroxidation in both blood and liver tissues was significantly reduced, and induction of pro-inflammatory cytokines interleukin-${\beta}$ and tumor necrosis factor-${\alpha}$, which elevate production of HbA1c and AGEs, was inhibited (P<0.05). To evaluate the possible cellular events after AGEs receptor activation, genetic expression of protein kinase C (PKC)-${\delta}$ and transforming growth factor (TGF)-${\beta}$ was measured by real-time polymerase chain reaction. Supplementation with both ASE 0.1% and 0.5% significantly inhibited mRNA expression of PKC-${\delta}$ and TGF-${\beta}$, indicating that ASE may have beneficial effects on preventing insulin-resistant cells or tissues from progressing to diabetic complications. Taken together, ASE has potential to improve type 2 diabetes by inhibiting insulin resistance and protein glycosylation, including production of HbA1c and AGEs. Anti-oxidative activities of ASE are a main requisite for reducing production of HbA1c and AGEs and are also related to regulation of the PKC signaling pathway, resulting in suppression of TGF-${\beta}$, which increases synthesis of collagen, prostaglandin, and disease-related proteins.

• Molecules and Cells
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• v.25 no.1
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• pp.105-111
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• 2008

Radiotherapy is an important treatment for many malignant tumors, but there are recent reports that radiation may increase the malignancy of cancer cells by stimulating expression of type IV collagenases. In this study, we examined changes in matrix metalloproteinase (MMP) inhibitors, such as the tissue inhibitors of metalloproteinase (TIMP)-1, TIMP-2 and RECK, in response to irradiation in Panc-1 pancreatic cancer cells. Irradiation increased RECK protein levels but not mRNA levels, whereas no significant changes were found in TIMP-1 and TIMP-2. The enhanced RECK protein levels were associated with an increase in MMP inhibitory activity. However, irradiation slightly but reproducibly increased the invasiveness of the Panc-1 cells. Like irradiation, treatment of Panc-1 cells with transforming growth factor $(TGF)-{\beta}1$ led to a 2-fold increase in RECK protein levels. Transient transfection with Smad3 also increased RECK protein levels, but transfection with Smad7 markedly reduced them. Stable expression of Smad7 and treatment with SB431542, an inhibitor of $TGF-{\beta}$ receptor I kinase, abolished $TGF-{\beta}1$- and radiation-mediated effects on RECK. Furthermore, irradiation increased levels of phosphorylated Smad3. We conclude that radiation post-transciptionally enhances RECK protein levels in Panc-1 cells, at least in part, via $TGF-{\beta}$ signaling, and that irradiation increases Panc-1 invasiveness via a mechanism that may not be linked to MMP-2 activity.

• Archives of Plastic Surgery
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• v.45 no.5
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• pp.403-410
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• 2018

Background Radiation-induced skin injury is a dose-limiting complication of radiotherapy. To investigate this problem and to develop a framework for making decisions on treatment and dose prescription, a murine model of radiation-induced skin injury was developed. Methods The dorsal skin of the mice was isolated, and irradiation was applied at single doses of 15, 30, and 50 Gy. The mice were followed for 12 weeks with serial photography and laser Doppler analysis. Sequential skin biopsy samples were obtained and subjected to a histological analysis, immunostaining against transforming growth factor beta (TGF-${\beta}$), and Western blotting with Wnt-3 and ${\beta}$-catenin. Increases in the levels of TGF-${\beta}$, Wnt, and ${\beta}$-catenin were detected after irradiation. Results All tested radiation doses caused progressive dermal thickening and fibrosis. The cause of this process, however, may not be radiation alone, as the natural course of wound healing may elicit a similar response. The latent appearance of molecular and histological markers that induce fibrosis in the 15 Gy group without causing apparent gross skin injuries indicates that 15 Gy is an appropriate dose for characterizing the effects of chronic irradiation alone. Thus, this model best mimics the patterns of injury that occur in human subjects. Conclusions This animal model can be used to elucidate the gross and molecular changes that occur in radiation-induced skin injury and provides an effective platform for studying this adverse effect without complicating the process of wound healing.

• BMB Reports
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• v.47 no.1
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• pp.21-26
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• 2014

Znf45l, containing classical $C_2H_2$ domains, is a novel member of Zinc finger proteins in zebrafish. In vertebrates, TGF-${\beta}$ signaling plays a critical role in hematopoiesis. Here, we showed that Znf45l is expressed both maternally and zygotically throughout early development. Znf45l-depleted Zebrafish embryos display shorter tails and necrosis with reduced expression of hematopoietic maker genes. Furthermore, we revealed that znf45l locates downstream of TGF-${\beta}$ ligands and maintains normal level of TGF-${\beta}$ receptor type II phosphorylation. In brief, our results indicate that znf45l affects initial hematopoietic development through regulation of TGF-${\beta}$ signaling.

• Journal of Microbiology and Biotechnology
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• v.23 no.7
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• pp.1023-1030
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• 2013

Lipoteichoic acid (LTA), uniquely expressed on gram-positive bacteria, is recognized by Toll-like receptor 2 (TLR2) on not only antigen-presenting cells but also activated T cells. Therefore, it is reasonable to assume that LTA is acting on T cells. However, little is known about the effect of LTA on T-cell regulation. In the present study, we investigated the immunomodulatory effects of LTA on $CD4^+$ T cells. Effector $CD4^+$ T cells, induced after co-culture with S. aureus-pulsed dendritic cells, produced high levels of interferon-${\gamma}$, CD25, CD69, and TLRs 2 and 4. When effector $CD4^+$ T cells were treated with LTA, the expressions of the membrane-bound form of transforming growth factor (TGF)-${\beta}$ and forkhead box P3 increased. Coincidently, the proliferation of effector $CD4^+$ T cells was declined after LTA treatment. When TGF-${\beta}$ signaling was blocked by the TGF-${\beta}$ receptor 1 kinase inhibitor, LTA failed to suppress the proliferation of effector $CD4^+$ T cells. Therefore, the present results suggest that LTA suppresses the activity of effector $CD4^+$ T cells by enhancing TGF-${\beta}$ production.