• Archives of Pharmacal Research
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• v.16 no.4
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• pp.276-282
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• 1993

This study has been undertaken to examine the effect of 3-methylcholanthrene (3MC) on rat uterine growth and to understand the mechanism of action of 3MC in rat uterus. After diethylstilbesterol(DES) or tamoxifen(TAM) or 3MC or DES plus TAM or DES plus 3MC was administered into immature female rats, uterine weight over corn oil-treated uteri. 3MC treatment had no effect on uterine weight but, DES stimulated uterine weight was inhibited by 3MC concomitant tratment. While TAM alone treatment showed slight increase in uterine wieght, inhibited uterine growth simulated by DES when it was adiministrated with DES condirect binding assay with $[^3H]$ estradiol and the relative binding affinities of 3MC and TAM were estimated by competetion assy. Estradiol tumed out to have high affinity for rat uterine estrogen receptor (kd = 0.4 nM). The relative binding affinities of TAM and 3MC were 1% and 4.7% that of DES for rat uterine estrogen receptor, respectively. 3MC was shown to have similar affinity for eat uterine estrogen receptor to that of TAM. Effects of DES 3MC and TAM administration in vivo on rat uterine estrogen recptor level were examined. It was confirmed that the estrogen, DES and antiestrogen, TAM decreased estrogen receptor levels from rat ulterus and also 3MC decreased rat uterine estrogen receptor level when rats were treated with DES, TAM and 3MC in vivo. Data indicates that 3MC acts as an antiestrogen mediated through estrogen receptor system.

• Molecules and Cells
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• v.42 no.1
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• pp.1-7
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• 2019

Macrophage is an important innate immune cell that not only initiates inflammatory responses, but also functions in tissue repair and anti-inflammatory responses. Regulating macrophage activity is thus critical to maintain immune homeostasis. Tyro3, Axl, and Mer are integral membrane proteins that constitute TAM family of receptor tyrosine kinases (RTKs). Growing evidence indicates that TAM family receptors play an important role in anti-inflammatory responses through modulating the function of macrophages. First, macrophages can recognize apoptotic bodies through interaction between TAM family receptors expressed on macrophages and their ligands attached to apoptotic bodies. Without TAM signaling, macrophages cannot clear up apoptotic cells, leading to broad inflammation due to over-activation of immune cells. Second, TAM signaling can prevent chronic activation of macrophages by attenuating inflammatory pathways through particular pattern recognition receptors and cytokine receptors. Third, TAM signaling can induce autophagy which is an important mechanism to inhibit NLRP3 inflammasome activation in macrophages. Fourth, TAM signaling can inhibit polarization of M1 macrophages. In this review, we will focus on mechanisms involved in how TAM family of RTKs can modulate function of macrophage associated with anti-inflammatory responses described above. We will also discuss several human diseases related to TAM signaling and potential therapeutic strategies of targeting TAM signaling.

• Oncology Letters
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• v.41 no.2
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• pp.1075-1082
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• 2019

In a previous study, we reported that α-smooth muscle actin (α-SMA), one of the mesenchymal marker proteins, is highly expressed in tamoxifen-resistant breast cancer (TamR) cells. However, the exact mechanism of α-SMA expression in TamR cells is not fully understood. Here, we investigated the effect of TP53 on α-SMA expression in breast cancer cells. The levels of α-SMA mRNA and protein expression were analyzed by real-time PCR and western blotting, respectively. In estrogen receptor-positive [ER(+)] breast cancer patients, aberrant α-SMA expression was found to be associated with a poor prognosis. The level of α-SMA expression was significantly increased in established TamR cells compared to tamoxifen-sensitive (TamS) cells. To verify the regulatory mechanism of α-SMA expression, we analyzed diverse kinase activities between TamS and TamR cells. The activity of TP53 was markedly increased in the TamR cells. When TamS cells were treated with TP53 activator, Nutlin3 (Nut3), α-SMA expression was increased in the TamS cells. In addition, α-SMA expression was significantly increased by TP53 overexpression in breast cancer cells. On the contrary, the basal level of α-SMA expression was decreased by the TP53 inhibitor, pifithrin-α (PFT-α). Taken together, we demonstrated that α-SMA expression is regulated by TP53 activity in TamR cells.

• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.2
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• pp.238-243
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• 2007

The TAM(Topographic Attentive Mapping) network neural network model is an especially effective one for pattern analysis. It is composed of of Input layer, category layer, and output layer. Fuzzy rule, lot input and output data are acquired from it. The TAM network with three pruning rules for reducing links and nodes at the layer is called fuzzy TAM network. In this paper, we apply fuzzy TAM network to pattern analysis of leadership type for organizational leader and show its usefulness. Here, criteria of input layer and target value of output layer are the value and leadership related personality type variables of the Egogram and Enneagram, respectively.

• Journal of the Korean Institute of Intelligent Systems
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• v.16 no.1
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• pp.86-93
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• 2006

The TAM(Topographic Attentive Mapping) network based on a biologically-motivated neural network model is an especially effective one for pattern analysis. It is composed of of input layer, category layer, and output layer. Fuzzy rule, for input and output data are acquired from it. The TAM network with three pruning rules for reducing links and nodes at the layer is called fuzzy TAM network. In this paper, we apply fuzzy TAM network to pattern analysis of core competency model for subcontractors of construction companies and show its usefulness.

• Communications of the Korean Mathematical Society
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• v.37 no.3
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• pp.881-891
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• 2022

In the present paper, we have studied Miao-Tam equation on three dimensional almost coKähler manifolds. We have also proved that there does not exist non-trivial solution of Miao-Tam equation on the said manifolds if the dimension is greater than three. Also we give an example to verify the deduced results.

• Journal of Sasang Constitutional Medicine
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• v.24 no.1
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• pp.54-65
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• 2012

1. Objective : The purpose of this study is to investigate the effects of TAM (Taraxacum mongolicum) on Th2 cytokine production in MC/9 mast cells. 2. Methods : The effects of TAM was analyzed by ELISA and Real-time PCR in MC/9 mast cells. Levels of IL-5, IL-13 were measured using enzyme-linked immunosorbent assays(ELISA). mRNA levels of IL-4, IL-5, IL-6, IL-13 were analyzed with Real-time PCR. 3. Results : 1) TAM inhibited the IL-4 production significantly in comparison to PI-control group at concentration of $50{\mu}g/ml$, $100{\mu}g/ml$, $200{\mu}g/ml$. 2) TAM inhibited the IL-13 production significantly in comparison to PI-control group at concentration of $50{\mu}g/ml$, $100{\mu}g/ml$, $200{\mu}g/ml$. 3) TAM inhibited the IL-4 mRNA expression significantly in comparison to PI-control group at concentration of $100{\mu}g/ml$. 4) TAM inhibited the IL-5 mRNA expression significantly in comparison to PI-control group at concentration of $50{\mu}g/ml$, $100{\mu}g/ml$. 5) TAM inhibited the IL-6 mRNA expression significantly in comparison to PI-control group at concentration of $100{\mu}g/ml$. 6) TAM inhibited the IL-13 mRNA expression significantly in comparison to PI-control group at concentration of $100{\mu}g/ml$. 4. Conclusions : These results indicate that TAM (Taraxacum mongolicum) has the effect of decreasing the Th2 cytokine production in the MC/9 mast cell.

• Journal of Life Science
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• v.20 no.9
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• pp.1324-1331
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• 2010

Mifepristone (MIF) and Tamoxifen (TAM) have been used in the treatment of prostate cancer and breast cancer for more than a decade. MIF can induce apoptosis in both AR-positive and negative prostate cancer cells. Because of its pleiotropic ligand-receptor properties, TAM exerts cytotoxic activity in estrogen (ER)-positive and various ER.negative cancer cells. However, the molecular mechanisms of these two substances are not yet clear. In the present work, we report that the cytotoxic effects of MIF and TAM are due to the modulation of intracellular $Ca^{2+}$ level in DU-145, androgen-insensitive cells. When the cells were treated with micromolar concentrations of either MIF or TAM, the growth and viability were significantly decreased in a dose- and time-dependent manner. The apoptosis induced by MIF or TAM was further proved and analyzed by confocal laser scanning microscopy (CLSM) and fluorescence-activated cell sorting (FACS). In the cells cultivated in a normal 1.5 mM $Ca^{2+}$ medium, both MIF and TAM also induced an increase of the intracellular $Ca^{2+}$ level in a dose-dependent fashion. Since a change in calcium level could not be found in cells of the $Ca^{2+}$-free medium, the increase of intracellular $Ca^{2+}$ level might be due to an increase in extracellular calcium uptake. Our results show that the apoptotic effect was more prominent in TAM treatment compared to MIF treatment in DU-145 cells. The above findings might be due to the difference in the uppermost pathways of apoptosis induced by either MIF or TAM. When we checked the level of procaspase-8 activation, TAM showed minor level of activation, as opposed to MIF, which exerted strong activation. In both treatments, the levels of anti-apoptotic protein Bcl-2 decreased, and pro-apoptotic protein Bax level increased more than 2-fold. The activation of caspase-3, a key protease enzyme in the downstream pathway of apoptosis, was much higher in the cells treated with TAM, compared to the MIF treatment. The overall apoptotic activity shown in the present work was closely related to intracellular $Ca^{2+}$ concentration levels. Therefore, the cytotoxic activity induced by MIF and TAM might have been due to intracellular calcium modulation.

• Journal of Digital Convergence
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• v.7 no.3
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• pp.13-24
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• 2009

Technology Acceptance Model (TAM) has been a basis model for testing technology use. Post researches of TAM have been conducted with the updating the TAM by adding new independent variables in order to increase the explanatory power of the model. However, the problem is that different independent variables have to be required to keep the explanatory power whenever adopting particular technology. This might reduce the generality of the research model. Thus in order to increase the generality of the model, this study reviewed the previous researches and collected the independent variables used, and regrouped them into three basic independent constructs. New research model was designed with three basic independent constructs with three constructs selected for the involuntary information technology usage environment. Finally, this study concluded that new technology acceptance model could be used to explain the use of new technology without any adding new particular independent variables.

• Genomics & Informatics
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• v.19 no.4
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• pp.39.1-39.8
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• 2021

Tamoxifen (TAM) is an anticancer drug used to treat estrogen receptor (ER)-positive breast cancer. However, its ER-independent cytotoxic and antifungal activities have prompted debates on its mechanism of action. To achieve a better understanding of the ER-independent antifungal action mechanisms of TAM, we systematically identified TAM-sensitive genes through microarray screening of the heterozygous gene deletion library in fission yeast (Schizosaccharomyces pombe). Secondary confirmation was followed by a spotting assay, finally yielding 13 TAM-sensitive genes under the drug-induced haploinsufficient condition. For these 13 TAM-sensitive genes, we conducted a comparative analysis of their Gene Ontology (GO) 'biological process' terms identified from other genome-wide screenings of the budding yeast deletion library and the MCF7 breast cancer cell line. Several TAM-sensitive genes overlapped between the yeast strains and MCF7 in GO terms including 'cell cycle' (cdc2, rik1, pas1, and leo1), 'signaling' (sck2, oga1, and cki3), and 'vesicle-mediated transport' (SPCC126.08c, vps54, sec72, and tvp15), suggesting their roles in the ER-independent cytotoxic effects of TAM. We recently reported that the cki3 gene with the 'signaling' GO term was related to the ER-independent antifungal action mechanisms of TAM in yeast. In this study, we report that haploinsufficiency of the essential vps54 gene, which encodes the GARP complex subunit, significantly aggravated TAM sensitivity and led to an enlarged vesicle structure in comparison with the SP286 control strain. These results strongly suggest that the vesicle-mediated transport process might be another action mechanism of the ER-independent antifungal or cytotoxic effects of TAM.