• Asian Pacific Journal of Cancer Prevention
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• v.15 no.7
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• pp.3005-3009
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• 2014

The aims of this study were to investigate the influence of ubiquitin- conjugating enzyme E2C (UBE2C) on biological behavior of lung cancer cells. Using MTT, flow cytometry and invasion assays, we detected UBE2C expression and evaluated its biological properties in these cells, including effects on proliferation, the cell cycle profile and invasive capability. Compared with control cells, the UBE2C transfected cells demonstrated increased cellular proliferation (p<0.05). UBE2C transfected cells also had a lower percentage in G1 phase and a higher percentage in S phase (p<0.05). Importantly, the UBE2C transfected cells had a notable enhancement of cell numbers penetrating the basement membrane compared with the control group (p<0.05). Ectopic up-regulation UBE2C promoted the growth of lung cancer cells in vivo. Furthermore, we found UBE2C increased the expression of cyclin D1 and MMP-2. These results show UBE2C may represent a potential therapeutic target for lung cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.7
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• pp.3223-3228
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• 2016

Reports indicate that 15-deoxy-delta-12,14-prostaglandin-J2 (15d-PGJ2) has anticancer activities, but its mechanisms of action have yet to be fully elucidated. We therefore investigated the effects of 15d-PGJ2 on the human breast cancer cell lines, MCF-7 (estrogen receptor $ER{\alpha}+/ER{\beta}+$) and MDA-MB-231 ($ER{\alpha}-/ER{\beta}+$). Cellular proliferation and cytotoxicity were determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays while apoptosis was determined by fluorescence microscopy and flow cytometry using annexin V-propidium iodide (PI) staining. ER expression was determined by Western blotting. Intracellular calcium was stained with Fluo-4 AM while intracellular caspase activities were detected with Caspase-$FLICA(R)$ and measured by flow cytometry. We showed that 15d-PGJ2 caused a significant increase in apoptosis in MCF-7 and MDA-MB-231 cells. $ER{\alpha}$ protein expression was reduced in treated MCF-7 cells but pre-incubation with the $ER{\alpha}$ inhibitor' ICI 182 780' did not affect the percentage of apoptotic cells. The expression of $ER{\beta}$ was unchanged in both cell lines. In addition, 15d-PGJ2 increased intracellular calcium ($Ca^{2+}$) staining and caspase 8, 9 and 3/7 activities. We therefore conclude that 15d-PGJ2 induces caspase-dependent apoptosis that is associated with an influx of intracellular $Ca^{2+}$ with no involvement of ER signaling.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2003.10a
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• pp.180-180
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• 2003

• Journal of Microbiology and Biotechnology
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• v.18 no.12
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• pp.1945-1952
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• 2008

Sialylation, the attachment of sialic acid residues to a protein, can affect the biological activity and in vivo circulatory half-life of glycoproteins. Human ${\alpha}2$,3-sialyltransferase (${\alpha}2$,3-ST) and ${\beta}1$,4-galactosyltransferase (${\beta}1$,4-GT) are responsible for terminal sialylation and galactosylation, respectively. Enhanced sialylation of human erythropoietin (EPO) by the expression of ${\alpha}2$,3-ST and ${\beta}1$,4-GT was achieved using recombinant Chinese hamster ovary (CHO) cells (EC1). The sialic acid content and sialylation of N-glycans were evaluated by HPLC. When ${\alpha}2$,3-ST was expressed in CHO cells (EC1-ST2), the sialic acid content (moles of sialic acid/mole of EPO) increased from 6.7 to 7.5. In addition, the amount of trisialylated glycans increased from 17.3% to 26.1 %. When ${\alpha}2$,3-ST and ${\beta}1$,4-GT were coexpressed in CHO cells (EC1-GTST15), the degree of sialylation was greater than that in EC1-ST2 cells. In the case of EC1-GTST15 cells, the sialic acid content increased to 8.2 and the proportion of trisialylated glycans was markedly increased from 17.3% to 35.5%. Interestingly, the amount of asialoglycans decreased only in the case of GTST15 cells (21.4% to 14.2%). These results show that coexpression of ${\alpha}2$,3-ST and ${\beta}1$,4-GT is more effective than the expression of ${\alpha}2$,3-ST alone. Coexpression of ${\alpha}2$,3-ST and ${\beta}1$,4-GT did not affect CHO cell growth and metabolism or EPO production. Thus, coexpression of ${\alpha}2$,3-ST and ${\beta}1$,4-GT may be beneficial for producing therapeutic glycoproteins with enhanced sialylation in CHO cells.

• The Korea Journal of Herbology
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• v.27 no.5
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• pp.15-20
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• 2012

Objectives : The purpose of this study was to estimate the antioxidant activity of water extract of Nelumbinis stamen (WNS) in GC-2 spd (ts) cells. Methods : we investigated the effect of WNS in mouse GC-2 spd (ts) cells by MTT assay. The protective effects of WNS against hydrogen peroxide-induced oxidative stress in GC-2 spd (ts) cells were examined by measuring cell viability. Lipid peroxidation levels and catalase were measured. Results : WNS showed cell viability as 101.9, 108.9, 111.8, 125.8, 134.5% in 2.5, 5, 10, 25, 50 ${\mu}g/ml$ concentrations, respectively. The protective effect of WNS concentration was 2.5 ${\mu}g/ml$ against hydrogen peroxide-induced oxidative stress in GC-2 spd (ts) cells. LPO were decreased significantly at 2.5, 5, 25 ${\mu}g/ml$ of WNS concentrations. Catalase activity was significantly increased at 2.5, 5 and 10 ${\mu}g/ml$ of WNS concentrations, respectively. Conclusions : In conclusion, WNS has antioxidant activities in GC-2 spd(ts) cells against oxidative stress.

• Journal of Embryo Transfer
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• v.11 no.3
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• pp.201-210
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• 1996

This experiment was carried out to evaluate the effect of early mouse embryonic development in vitro by co-culture with bovine and porcine oviductal epithelial cells (BOEC and POEC). The 2-cell embryos were collected from the oviducts of the superovulated and mated cultured in D-PBS /15% FCS at 48 hours after hCG injection. The in vitro developmental rate of blastocyst formation in the embryos were examined under the fllowing treatments; 1) TCM 199 added 15% HCS, 2) Ham's F-10 added 15% HCS, 3) MediCult IVF medium, 4) TCM 199 added 15% HCS + BOEC, 5) TCM 199 added 15% HCS + POEC, 6) Ham's F40 added 15% HCS + BOEC, 7) Ham's F-10 added 15% HCS + POEC,8) MediCult IVF medium + BOEC, 9) MediCult IVF medium + POEC. For a comparative study of in vitro development for 96 hours after hCG injection, were cultured with oviductal epithelial cell and media only. The obtained results were 2-cell embryos developed to the blastocyst stage in TCM 199, Ham's F-10 and MediCult IVF medium at the rates of 84.4,83.2 and 81.6%. respectively. The higher developmental rates(91~97%) of blastocyst formation was appeared when the embryos were co-cultured with a monolayer of bovine or porcine oviductal epithelial cells in TCM 199 or Ham's F-10 and MediCult IVF media. No significant difference in developmental rates was shown between bovine and porcine oviductal epithelial cells but significant difference in co-culture system in comparison between media only system and co-cultures. In conclusions, oviductal epithelial cells, BOEC and POEC, when co-culture with mouse early embryos improved the rates of development, blastocyst and hatching. Therefore, it is suggested that co-culture system using oviductal epithelial cells improve early embryonic developtnent in mouse.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.9
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• pp.4039-4044
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• 2014

Background: The aim of this study was to investigate the anti-cancer effects and mechanisms of immunochemotherapy of 5-fluorouracil (5-FU) and interleukin-2 (IL-2) on non-small cell lung cancer (NSCLC) A549 cells. Materials and Methods: In order to detect whether 5-FU+IL-2 could effectively inhibit tumor growth in vivo, we established an A549-bearing nude mouse model. The cytotoxicity of natural killer (NK) cells was evaluated using a standard chromium release assay. To evaluate the relevance of NK cells in 5-FU+IL-2-mediated tumor inhibitory effects, we depleted NK cells in A549-bearing mice by injecting anti-asialo-GM-1 antibodies. Effects of 5-FU+IL-2 on the expression and promoter activity of NKG2D ligands (MICA/MICB) in A549 cells in vitro were also assessed. Results: In A549-bearing nude mice, combination therapy significantly inhibited tumor growth in comparison with monotherapy with 5-FU or IL-2 and enhanced the recognition and lysis of tumor cells by NK cells. Further study of mechanisms showed that NK cells played a vital role in the anticancer immune response of 5-FU+IL-2 immunochemotherapy. In addition, the combination therapy synergistically stimulated the expression and promoter activity of MICA/MICB. Conclusions: 5-FU and IL-2 immunochemotherapy significantly inhibited tumor growth and activated NK cytotoxicity in vivo, and these effects were partly impaired after depleting NK cells in tumor-bearing mice. Combination treatment of 5-FU and IL-2 upregulated the expression and the promoter activity of MICA/MICB in A549 cells, which enhanced the recognition of A549 cells by NK cells. All of the data indicated that immunochemotherapy of 5-FU and IL-2 may provide a new treatment option for patients with lung cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.18
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• pp.7857-7861
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• 2014

Natural killer (NK) cells play an important role in anti-tumor immunity. Interleukin (IL)-18 is an immunoregulatory cytokine that induces potent NK cell-dependent anti-tumor responses when administrated with other cytokines. In this study, we explored the effects of combining IL-18 and IL-2 on NK cytotoxicity as well as expression levels of the NK cell receptor NKG2D in vitro. Freshly isolated PBMCs were incubated for 48 h with IL-18 and IL-2, then CD107a expression on $CD3^-CD56^+$ NK cells was determined by three-colour flow cytometry to evaluate the cytotoxicity of NK cells against human erythroleukemia K562 cells and human colon carcinoma HT29 cells. Flow cytometric analysis was also employed to determine NKG2D expression on NK cells. The combined use of IL-18 and IL-2 significantly increased CD107a expression on NK cells compared with using IL-18 or IL-2 alone, suggesting that the combination of these two cytokines exerted synergistic enhancement of NK cytotoxicity. IL-18 also enhanced NKG2D expression on NK cells when administered with IL-2. In addition, blockade of NKG2D signaling with NKG2D-blocking antibody attenuated the up-regulatory effect of combining IL-18 and IL-2 on NK cytolysis. Our data revealed that IL-18 synergized with IL-2 to dramatically enhance the cytolytic activity of human NK cells in a NKG2D-dependent manner. The results appear encouraging for the use of combined IL-18 and IL-2 in tumor immunotherapy.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.6
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• pp.511-518
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• 2001

The effect of mycolactone, a recently reported apoptosis-inducing factor, was investigated in SCC15 oral squamous cell carcinoma(OSCC) cell line. Mycolactone rapidly induced cell death in OSCC cells in 2days, which was similar to that found in apoptotic cell such as detaching from culture plate and rounding-up of cells. Apoptotic cells were increased 4hrs after mycolactone treatment and more than half of cells showed apoptosis after 72hrs. Caspase 3 activation a biochemical evidence of apoptosis, was determined by Western blotting. Caspase 3 activation was started at 2hrs that lasted until 8hrs after mycolactone treatment. The expression of bcl-2 family genes was determined to explain the mechanism of apoptosis found in OSCC cells. The expressions of bad, bak, and bax (pro-apoptotic genes) and bcl-w and bcl-2 genes (anti-apoptotic genes) were not changed by mycolactone treatment. The expression of bcl-xi was decreased 8 hrs after mycolactone treatment. Mcl-1 expression was initially increased at 2 hrs which was decreased 8 hrs after mycolactone treatment. The down-regulation of these two anti-apoptotic genes might explain the mycolactone-induced apoptosis in OSCC cells. In this study, mycholactone was revealed to induce cell death in OSCC cells apoptosis and the apoptosis mechanism of OSCC cells was shown to be down-regulation of anti-apoptotic genes, bcl-xi and mcl-1. These results suggested the applicability of mycolactone for the development of an anti-cancer drug candidate by inducing apoptosis of OSCC cancer cell.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.11
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• pp.6761-6767
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• 2013

The nuclear receptor, peroxisome proliferator-activated receptor gamma ($PPAR{\gamma}$), is expressed in various cancer cells including breast, prostate, colorectal and cervical examples. An endogenous ligand of $PPAR{\gamma}$, 15-deoxy-${\Delta}^{12,14}$ prostaglandin $J_2$ (PGJ2), is emerging as a potent anticancer agent but the exact mechanism has not been fully elucidated, especially in breast cancer. The present study compared the anticancer effects of PGJ2 on estrogen receptor alpha ($ER{\alpha}$)-positive (MCF-7) and $ER{\alpha}$-negative (MDA-MB-231) human breast cancer cells. Based on the reported signalling cross-talk between $ER{\alpha}$ and $ER{\alpha}$, the effect of the $ER{\alpha}$ ligand, $17{\beta}$-estradiol (E2) on the anticancer activities of PGJ2 in both types of cells was also explored. Here we report that PGJ2 inhibited proliferation of both MCF-7 and MDA-MB-231 cells by inducing apoptotic cell death with active involvement of mitochondria. The presence of E2 potentiated PGJ2-induced apoptosis in MCF-7, but not in MDA-MB-231 cells. The $ER{\alpha}$ antagonist, GW9662, failed to block PGJ2-induced activities but potentiated its effects in MCF-7 cells, instead. Interestingly, GW9662 also proved capable of inducing apoptotic cell death. It can be concluded that E2 enhances $ER{\alpha}$-independent anticancer effects of PGJ2 in the presence of its receptor.