• The Korean Journal of Physiology and Pharmacology
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• v.24 no.3
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• pp.267-276
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• 2020

T In the present study, we investigated the effect of oncogenic H-Ras on rat mdr1b expression in NIH3T3 cells. The constitutive expression of H-Ras^V12 was found to downregulate the mdr1b promoter activity and mdr1b mRNA expression. The doxorubicin-induced mdr1b promoter activity of the H-Ras^V12 expressing NIH3T3 cells was markedly lower than that of control NIH3T3 cells. Additionally, there is a positive correlation between the level of H-Ras^V12 expression and a sensitivity to doxorubicin toxicity. To examine the detailed mechanism of H-Ras^V12-mediated down-regulation of mdr1b expression, antioxidant N-acetylcysteine (NAC) and NADPH oxidase inhibitor diphenylene iodonium (DPI) were used. Pretreating cells with either NAC or DPI significantly enhanced the oncogenic H-Ras-mediated down-regulation of mdr1b expression and markedly prevented doxorubicin-induced cell death. Moreover, NAC and DPI treatment led to a decrease in ERK activity, and the ERK inhibitors PD98059 or U0126 enhanced the mdr1b-Luc activity of H-Ras^V12-NIH3T3 and reduced doxorubicin-induced apoptosis. These data suggest that Ras^V12 expression could downregulate mdr1b expression through intracellular reactive oxygen species (ROS) production, and ERK activation induced by ROS, is at least in part, contributed to the downregulation of mdr1b expression.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2002.05a
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• pp.81-81
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• 2002

• BMB Reports
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• v.47 no.12
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• pp.685-690
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• 2014

The Ras/Raf/MEK/Erk signaling pathway is important for regulation of cell growth, proliferation, differentiation, survival, and apoptosis in response to a variety of extracellular stimuli. Lack of Erk MAPK activation is observed in several cancer cells despite active activation of Ras. However, little is known about the modulation of Erk1/2 activity by active Ras. Here, we show that overexpression of active H-Ras (H-RasG12R) in NIH3T3 fibroblasts impaired FGF2-induced Erk1/2 phosphorylation, as compared to wild-type cells. Northern blot analysis revealed that prolonged expression of active Ras increased MAP kinase phosphatase 3 (MKP3) mRNA expression, a negative regulator of Erk MAPK. Inhibition of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway abrogated active Ras-induced up-regulation of MKP3 expression, leading to the rescue of Erk1/2 phosphorylation. Our results demonstrated that the Ras/Raf/MEK/Erk signaling cascade is negatively regulated by the PI3K/Aktdependent transcriptional activation of the MKP3 gene.

• Journal of Society of Preventive Korean Medicine
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• v.12 no.3
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• pp.47-58
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• 2008

The anticancer and antioxidant effect of different lengths of saturated fatty acids was tested on NIH3T3 fibroblasts and human skin melanoma cellsn in this study. The cell existence rate and antioxidizing capacity and optic reservation of cells were observed. This saturated fatty acid was concentration-dependent. IC50 Concentrations in NIH3T3 fibroblasts, human skin melanoma cells and DPPH radical scavenging activity of fatty acid was increasing the order of carbochain length ; caprylic acid < lauric acid < palmitic acid < stearic acid. The reduction in cell number and morphological change in human skin melanoma cells was increasing the order of carbochain length ; caprylic acid < lauric acid < palmitic acid < stearic acid. These results suggest that carbochain length of fatty acid can be used as structure-activity relationships for anticancer and antioxidant.

• BMB Reports
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• v.35 no.5
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• pp.452-458
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• 2002

Exposure to ultraviolet light (UV) induces apoptosis in mammalian cells, The caspase group of proteases is required for the appotosis. This pathway is initiated by a release of cytochrome c from the mitochondria into the cytosol. Several Bcl-2 family proteins can regulate the release of cytochrome c by stabilizing the mitochondrial membrane. Here we show that expression of the endogenous bcl-xL was strongly downregulated in NIH3T3 cells within 2 h after UV-C irradiation, and that of bax was upregulated from 8 h after irradiation. Apoptosis was induced in more than 50% of the NIH3T3 cells 48 h after irradiation. Constitutive overexpression of bcl-xL in NIH3T3 cells protected the UV-induced apoptosis by preventing the loss of mitochondrial membrane potential and the activation of caspase 9. There results suggest that downregulation of Bcl-xL is relevant to UV-induced apoptosis of tibroblasts.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.2
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• pp.236-240
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• 2013

In this presentation, we propose a fabrication method of PDMS stencil to apply into a localized culture of NIH/3T3 cells. PDMS stencil was fabricated by nitrogen gas blowing and soft lithography from preparing SU-8 master mold by photolithography. PDMS stencil pattern was production of the circle size 20 to $500{\mu}m$. In the culture test of PDMS stencil, a stencil was placed on a glass disk. The NIH/3T3 cells were successfully cultured into micropatterns by using the PDMS stencil. The results showed that cells could be cultured into micropatterns with precisely controlled manner at any shapes and specific size for bioscience study and bioengineering applications.

• Journal of Life Science
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• v.27 no.11
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• pp.1269-1275
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• 2017

Tenebrio molitor samples were investigated as novel biomaterials and sources of food in several recent studies. However, the insects' effects on hair growth were not sufficiently researched. To develop novel and natural materials for preventing alopecia and promoting hair growth, this study investigated the antioxidant activities and hair-growth promotion effects of TMEs. To determine the antioxidant activities, the TMEs' DPPH radical- and nitrite-scavenging activities were examined. To determine hair-growth promotion effects, proliferations of human dermal papilla cells (DPCs) and the murine fibroblast cell line NIH3T3 were evaluated by using an MTS assay. In addition, estimations were made for cell viabilities against cell death induced by dihydrotesterone (DHT) in DPCs and inhibitory effects against potassium channel blocking induced by tolbutamide (TBM) in NIH3T3 cells. The DPPH radical scavenging activity was 81.17%, and the nitrite scavenging activity was 43.69%; the activities were similar to the activities of blueberry extracts. Moreover, the TMEs promoted the proliferation of human DPCs and NIH3T3 cells, which were concentrated dependently. The TMEs prevented not only DHT-induced DPC cytotoxicity but also TBM's action as a potassium channel blocker in NIH3T3 cells. The results suggested that TME could be used as a functional therapeutic alopecia reagent, to prevent hair loss and to promote hair growth.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.24 no.1
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• pp.87-99
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• 1998

We have studied the effects of red ginseng root extract on the derease of MMS-induced gemotoxicity in cultured NIH3T3 cells. The increase in survival and the recovery from DNA synthesis inhibition in MMS-treated cells as a function of normal medium incubation time was potentiated, at a rate higher than those in UV-irradiated cells, by the presence of the ginseng extract. The extract also increased the MMS-induced excision repair as determined by unscheduled DNA synthesis. The amount of MMS-induced DNA single strand breads that are accumulated by polymerase inhibitors was increased, but as a rate lower rate than in UV-induced strand break, by the presence of the extract. These results suggest that the red ginseng extract increase MMS-induced repair and could be used as a reagent for protectiong alkylating agent-induced genotoxicity and cytotoxicity.

• The Korean Journal of Physiology and Pharmacology
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• v.24 no.3
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• pp.233-240
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• 2020

Autophagy regulators are often effective as potential cancer therapeutic agents. Here, we investigated paclitaxel sensitivity in cells with knockout (KO) of ATG5 gene. The ATG5 KO in multidrug resistant v-Ha-ras-transformed NIH 3T3 cells (Ras-NIH 3T3/Mdr) was generated using the CRISPR/Cas9 technology. The qPCR and LC3 immunoblot confirmed knockout of the gene and protein of ATG5, respectively. The ATG5 KO restored the sensitivity of Ras-NIH 3T3/Mdr cells to paclitaxel. Interestingly, ATG5 overexpression restored autophagy function in ATG5 KO cells, but failed to rescue paclitaxel resistance. These results raise the possibility that low level of resistance to paclitaxel in ATG5 KO cells may be related to other roles of ATG5 independent of its function in autophagy. The ATG5 KO significantly induced a G₂/M arrest in cell cycle progression. Additionally, ATG5 KO caused necrosis of a high proportion of cells after paclitaxel treatment. These data suggest that the difference in sensitivity to paclitaxel between ATG5 KO and their parental MDR cells may result from the disparity in the proportions of necrotic cells in both populations. Thus, our results demonstrate that the ATG5 KO in paclitaxel resistant cells leads to a marked G₂/M arrest and sensitizes cells to paclitaxel-induced necrosis.

• Journal of Society of Preventive Korean Medicine
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• v.5 no.1
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• pp.144-150
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• 2001

The cytotoxic activity of Cratalariae sessiliflorae on cultured NIH 3T3 fibroblasts and human oral epithelioid carcinoma cells (KB) were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazoliumbromide (MTT) colorimetric method These fractions of methanol extract of Cratalariae sessiliflorae showed inhibitory effect in vitro in the milligram range against KB cell lines. In general, the antitumor activities of these fractions were does-dependent over the milligram range. The comparison of IC50 values of these fractions in tumor cell lines showed that their susceptibility to these fractions decrease in the following order: Fr. 4> Fr. 6> Fr. 10> Fr. 2> Fr. 11> Fr. 3> Fr. 8> Fr. 7> Fr. 9> Fr. 1> Fr. 5 by the MTT assay. These fractions were tested for their cytotoxic effects on NIH 3T3 fibroblasts using MTT assay. They exhibited potent cytotoxic activities in vitro in the milligram range against NIH 3T3 fibroblasts. In general, the cytotoxic activities of these fractions were does-dependent over the milligram range. The comparison of CD50 values of these fractions in NIH 313 fibroblasts shows that their susceptibility to these fractions in decrease the following order: Fr. 10> Fr. 9> Fr. 2 = Fr. 4> Fr. 8> Fr. 11> Fr. 1 = Fr. 7> Fr. 3> Fr. 5 = Fr. 6 by the MTT assay. These results suggests that fraction 5 has the most growth - inhibitory activity against KB cell lines.