• International Journal of Vascular Biomedical Engineering
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• v.1 no.2
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• pp.4-12
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• 2003

The present study investigated the effect of transverse vibration on the hemorheological characteristics of blood using a newly designed pressure-scanning capillary viscometer. As vibration was applied, aggregated blood cells (rouleaux) were disaggregated. The range of vibration frequency and amplitude are $0{\sim}100\;Hz$ and $0{\sim}0.8\;mm$, respectively for a capillary diameter 0.84 mm. As vibration increased, blood viscosity initially increased and tended to decrease. In order to delineate the unexpected results, the present study proposed two counteracting mechanisms of vibration related with red blood cell (RBC) aggregation affecting hemo-rheological properties. One is the reduction of RBC aggregation due to vibration causing an increase of blood viscosity. The other is forced cell migration due to the transverse vibration, which in turn forms a cell-free layer near the tube wall and causes a decrease of flow resistance.

• Environmental Mutagens and Carcinogens
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• v.17 no.2
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• pp.71-77
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• 1997

The single cell gel electrophoressis(SCGE) assay, also known as the comet assay, is a rapid, simple, visual and sensitive technique for measuring and analysing DNA breakage in mammalian cells. The SCGE or comet assay is a promising test for the detection of DNA damage and repair in individnal cells. It has widespread potential applications in DNA damage and repair studies, genotoxicity testing and biomonitoring. In this microgel electrophoresis technique, cells are embedded in agarose gel on microscope slides, iysed and electrophoresed under alkaline conditions. Cells with increased DNA damage display increased migration of DNA from the nucleus towards the anode. The length of DNA migration indicates the amount of DNA breakage in the cell. The comet assay is also capable of identifying apoptotic cells which contain highly fragmented DNA. Here we review the development of the SCGE assay, existing protocols for the detection and analysis of comets, the relevant underlying principles determining the behaviour of DNA and the potential applications of the technique.

• Molecules and Cells
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• v.37 no.10
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• pp.759-765
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• 2014

N-myc downstream-regulated gene 2 (NDRG2), which is known to have tumor suppressor functions, is frequently down-regulated in breast cancers and potentially involved in preventing the migration and invasion of malignant tumor cells. In the present study, we examined the inhibitory effects of NDRG2 overexpression, specifically focusing on the role of cyclooxygenase-2 (COX-2) in the migration of breast cancer cells. NDRG2 overexpression in MDA-MB-231 cells inhibited the expression of the COX-2 mRNA and protein, the transcriptional activity of COX-2, and prostaglandin $E_2$ ($PGE_2$) production, which were induced by a treatment with phorbol-12-myristate-13-acetate (PMA). Nuclear transcription factor-${\kappa}B$ (NF-${\kappa}B$) signaling attenuated by NDRG2 expression resulted in a decrease in PMA-induced COX-2 expression. Interestingly, the inhibition of COX-2 strongly suppressed PMA-stimulated migration and invasion in MDA-MB-231-NDRG2 cells. Moreover, siRNA-mediated knockdown of NDRG2 in MCF7 cells increased the COX-2 mRNA and protein expression levels and the PMA-induced COX-2 expression levels. Consistent with these results, the migration and invasion of MCF7 cells treated with NDRG2 siRNA were significantly enhanced following treatment with PMA. Taken together, our data show that the inhibition of NF-${\kappa}B$ signaling by NDRG2 expression is able to suppress cell migration and invasion through the down-regulation of COX-2 expression.

• The Korean Journal of Physiology and Pharmacology
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• v.15 no.4
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• pp.211-216
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• 2011

Glioblastoma multiforme is one of the most common and aggressive tumors in central nervous system. It often possesses characteristic necrotic lesions with hemorrhages, which increase the chances of exposure to thrombin. Thrombin has been known as a regulator of MMP-9 expression and cancer cell migration. However, the effects of thrombin on glioma cells have not been clearly understood. In the present study, influences of thrombin on glioma cell migration were examined using Boyden chamber migration assay and thrombin-induced changes in MMP-9 expression were measured using zymography, semi-quantitative RT-PCR, and Western blotting. Furthermore, underlying signaling pathways by which thrombin induces MMP-9 expression were examined. Thrombin-induced migration and MMP-9 expression were significantly potentiated in the presence of wortmannin, a PI3K inhibitor, whereas MAPK inhibitors suppressed thrombin-induced migration and MMP-9 expression in C6 glioma cells. The present data strongly demonstrate that MAPK and PI3K pathways evidently regulate thrombin-induced migration and MMP-9 expression of C6 glioma cells. Therefore, the control of these pathways might be a beneficial therapeutic strategy for treatment of invasive glioblastoma multiforme.

• BMB Reports
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• v.51 no.10
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• pp.532-537
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• 2018

Prostaglandin $E_2$ ($PGE_2$), a major product of cyclooxygenase-2 (COX-2), plays an important role in the carcinogenesis of many solid tumors, including colorectal cancer. Because $PGE_2$ functions by signaling through $PGE_2$ receptors (EPs), which regulate tumor cell growth, invasion, and migration, there has been a growing amount of interest in the therapeutic potential of targeting EPs. In the present study, we investigated the role of EP4 on the effectiveness of cordycepin in inhibiting the migration and invasion of HCT116 human colorectal carcinoma cells. Our data indicate that cordycepin suppressed lipopolysaccharide (LPS)-enhanced cell migration and invasion through the inactivation of matrix metalloproteinase (MMP)-9 as well as the down-regulation of COX-2 expression and $PGE_2$ production. These events were shown to be associated with the inactivation of EP4 and activation of AMP-activated protein kinase (AMPK). Moreover, the EP4 antagonist AH23848 prevented LPS-induced MMP-9 expression and cell invasion in HCT116 cells. However, the AMPK inhibitor, compound C, as well as AMPK knockdown via siRNA, attenuated the cordycepin-induced inhibition of EP4 expression. Cordycepin treatment also reduced the activation of CREB. These findings indicate that cordycepin suppresses the migration and invasion of HCT116 cells through modulating EP4 expression and the AMPK-CREB signaling pathway. Therefore, cordycepin has the potential to serve as a potent anti-cancer agent in therapeutic strategies against colorectal cancer metastasis.

• Preventive Nutrition and Food Science
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• v.15 no.2
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• pp.137-142
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• 2010

Previous studies report that organo-sulfur compounds derived from garlic inhibited smooth muscle cell (SMC) proliferation and induced apoptosis of cancer cells. Recently, lipid-soluble compounds such as diallyl sulfides (DAS) and diallyl disulfides (DADS) have been reported to more effectively suppress tumor cell proliferation. However, there were few studies on the suppressive effects of lipid-soluble garlic sulfur compounds on the proliferation and migration of vascular smooth muscle cells (VSMC). Therefore, this study investigated the effect of DAS and DADS on VSMC proliferation/migration induced by oleic acid (OA), a principal fatty acid in circulating triglyceride of blood stream. Assays performed include a tetrazole (MTT) assay, a wound healing assay and a Western blots. VSMC proliferations were enhanced by OA in a dose-dependent manner at concentrations of $10{\sim}50\;{\mu}M$ and inhibited by DAS and DADS compared to non-treated control. OA-induced proliferations were also attenuated by DAS and DADS. OA-induced cell migrations were 2.5 times higher than non-treated control, and they were significantly attenuated by DAS (32% at $150\;{\mu}M$ and 50% at $200\;{\mu}M$) and DADS (40% at $150\;{\mu}M$ and 46% at $200\;{\mu}M$). OA-induced cell migration was also attenuated by PD98059 (ERK inhibitor), SB203580 (P38 inhibitor) and particularly by LY204002 (PI3K inhibitor) and SP600125 (JNK2 inhibitor). Additionally, Western blot assays showed that OA-induced JNK1/2-phosphorylation was down-regulated after treatment with DAS and DADS. In conclusion, the findings of our study support the idea that DAS and DADS may have a suppressive effect on the proliferation and migration of OA-induced VSMC and that this effect may be partly associated with PI3K and JNK2 pathways.

• Journal of Life Science
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• v.24 no.4
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• pp.337-342
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• 2014

Resveratrol (RSV), a natural polyphenolic compound, is a modulator for cell division and cell migration, and has diverse beneficial properties. Angiogenin (ANG) and vascular endothelial growth factor (VEGF) are considered to be important mechanisms for cell proliferation, angiogenesis, the formation of tubular structures, and migration. In this study, we investigated whether RSV has a migratory effect in HeLa cells. When cells were treated with $0{\sim}50{\mu}M$ of RSV for 24 hr, the expression of ANG and VEGF was significantly increased in a dose dependent manner measured by real-time PCR. Similarly, we performed time dependent experiments for $50{\mu}M$ RSV treated cells and identified the optimized time at 24 hr. The increased expression in RSV treated cells was confirmed by Western blot analysis. To examine the toxic effects of RSV at the determined conditions, MTT assays were performed. The viabilities were unchanged for $0{\sim}50{\mu}M$ RSV treated cells, while they decreased at $100{\mu}M$ RSV. To examine the effect of migration in RSV treated cells, we performed a wound-healing assay. The migratory rates were significantly enhanced in the RSV treated group. In this study, we found that RSV induces an increase in the expression of migration factors ANG, VEGF, and enhances cell migration for the determined conditions.

• Molecules and Cells
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• v.43 no.11
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• pp.921-934
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• 2020

Lck-interacting transmembrane adaptor 1 (LIME) has been previously identified as a raft-associated transmembrane protein expressed predominantly in T and B lymphocytes. Although LIME is shown to transduce the immunoreceptor signaling and immunological synapse formation via its tyrosine phosphorylation by Lck, a Src-family kinase, the in vivo function of LIME has remained elusive in the previous studies. Here we report that LIME is preferentially expressed in effector T cells and mediates chemokine-mediated T cell migration. Interestingly, in LIME^-/- mice, while T cell receptor stimulation-dependent proliferation, differentiation to effector T cells, cytotoxic T lymphocyte (CTL) function and regulatory T lymphocyte (Treg) function were normal, only T cell-mediated inflammatory response was significantly defective. The reduced inflammation was accompanied by the impaired infiltration of leukocytes and T cells to the inflammatory sites of LIME^-/- mice. More specifically, the absence of LIME in effector T cells resulted in the reduced migration and defective morphological polarization in response to inflammatory chemokines such as CCL5 and CXCL10. Consistently, LIME^-/- effector T cells were found to be defective in chemokine-mediated activation of Rac1 and Rap1, and dysregulated phosphorylation of Pyk2 and Cas. Taken together, the present findings show that LIME is a critical regulator of inflammatory chemokine-mediated signaling and the subsequent migration of effector T cells to inflammatory sites.

• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3715-3721
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• 2013

In this study, the behavior of cells on the modified surface, and the correlation between the modified substrates and the response of cells is described. A close-packed layer of nano-sized silica beads was prepared on a coverslip, and the adhesion, proliferation, and migration of BALB/3T3 fibroblast cells on the silica layer was monitered. The 550 nm silica beads were synthesized by the hydrolysis and condensation reaction of tetraethylorthosilicate in basic solution. The amine groups were introduced onto the surfaces of silica particles by treatment with 3-aminopropyltrimethoxysilane. The close-packed layer of silica beads on the coverslip was obtained by the reaction of the amine-functionalized silica beads and the (3-triethoxysilyl)propylsuccinic anhydride treated coverslip. BALB/3T3 fibroblast cells were loaded on bare glass, APTMS coated glass, and silica bead coated glass with the same initial cell density, and the migration and proliferation of cells on the substrates was investigated. The cells were fixed and stained with antibodies in order to analyze the changes in the actin filaments and nuclei after culture on the different surfaces. The motility of cells on the silica bead coated glass was greater than that of the cells cultured on the control substrate. The growth rate of cells on the silica bead coated glass was slower than that of the control. Because the close-packed layer of silica beads gave an embossed surface, the adhesion of cells was very weak compared to the smooth surfaces. These results indicate that the adhesion of cells on the substrates is very important, and the actin filaments might play key roles in the migration and proliferation of cells. The nuclei of the cells were shrunk on the weakly adhered surfaces, and the S1 stage in which DNA is duplicated in the cell dividing processes might be retarded. As a result, the rate of proliferation of cells was decreased compared to the smooth surface of the control. In conclusion, the results described here are very important in the understanding of the interaction between implanted materials and biosystems.

• Molecules and Cells
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• v.39 no.8
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• pp.611-618
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• 2016

Fibroblast-like synoviocytes (FLS) with aberrant expression of microRNA (miRNA) are critical pathogenic regulators in rheumatoid arthritis (RA). Previous studies have found that overexpression or silencing of miRNA can contribute to the development of miRNA-based therapeutics in arthritis models. In this study, we explored the effects of miR-27a on cell migration and invasion in cultured FLS from RA patients. We found that miR-27a was markedly downregulated in the serum, synovial tissue, and FLS of RA patients. Meanwhile, the expression of follistatin-like protein 1 (FSTL1) was upregulated, which suggests that FSTL1 plays a key role in RA development. The results of a Transwell assay showed that miR-27a inhibited FLS migration and invasion. However, miR-27a inhibition promoted the migration and invasion of FLS. In addition, the down-regulated expression of matrix metalloproteinases (MMP2, MMP9, and MMP13) and Rho family proteins (Rac1, Cdc42, and RhoA) was detected after treatment with miR-27a in RA-FLS by quantitative reverse transcription-PCR and western blot analysis. Then, a luciferase reporter assay validated that miR-27a targeted the 3-untranslated region (3'-UTR) of FSTL1. Moreover, miR-27a caused a significant decrease of FSTL1. In addition, the expression of TLR4 and $NF{\kappa}B$ was inhibited by miR-27a but increased by FSTL1 overexpression. In conclusion, we found that miR-27a inhibited cell migration and invasion of RA-FLS by targeting FSTL1 and restraining the $TLR4/NF{\kappa}B$ pathway.