• Archives of Pharmacal Research
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• v.28 no.6
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• pp.722-729
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• 2005

With the aim to improve the specificity and to reduce the cytotoxicity of polyethylenimine (PEI), we have synthesized the conjugates of the branched PEI (25 kDa) with transferrin. The trans-ferrin-PEI (TP) conjugates with five compositions were synthesized using periodate oxidation method and confirmed by FT-IR spectroscopy and gel permeation chromatography. The free amine contents of TP conjugates, which were able to condense and deliver DNA, increased as the amount of PEI increased. TP/DNA polyplexes were characterized by measuring gel elec-trophoresis, ethidium bromide fluorescence quenching, particle size and zeta potential of complexes. Complete complexation of the polyplexes was observed above the N/P ratio of 5 in TP/DNA, and above 3 in PEI/DNA, respectively. The zeta potential of the complexes decreased as the amount of transferrin in TP conjugates increased. Transfection efficiency of TP conjugates was evaluated in HeLa cell and Jurkat cell systems. Among the five compositions of TP conjugates, TP-2 system mediated a higher $\beta$-galactosidase gene expression than PEI system in Jurkat cell which was known to express elevated numbers of transferrin receptors. From the results of the cell viability based on MTT assay, TP conjugates showed lower cytotoxicity com-pared with the PEI system. We expect that the TP conjugate can be used efficiently as a non-viral gene delivery vector.

• BMB Reports
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• v.53 no.8
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• pp.437-441
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• 2020

In accordance with requirements of the ICH S7B safety pharmacology guidelines, numerous next-generation cardiotoxicity studies using human stem cell-derived cardiomyocytes (CMs) are being conducted globally. Although several stem cell-derived CMs are being developed for commercialization, there is insufficient research to verify if these CMs can replace animal experiments. In this study, in vitro high-efficiency CMs derived from human embryonic stem cells (hESC-CMs) were compared with Sprague-Dawley rats as in vivo experimental animals, and primary cultured in vitro rat-CMs for cardiotoxicity tests. In vivo rats were administrated with two consecutive injections of 100 mg/kg isoproterenol, 15 mg/kg doxorubicin, or 100 mg/kg nifedipine, while in vitro rat-CMs and hESC-CMs were treated with 5 μM isoproterenol, 5 μM doxorubicin, and 50 μM nifedipine. We have verified the equivalence of hESC-CMs assessments over various molecular biological markers, morphological analysis. Also, we have identified the advantages of hESC-CMs, which can distinguish between species variability, over electrophysiological analysis of ion channels against cardiac damage. Our findings demonstrate the possibility and advantage of high-efficiency hESC-CMs as next-generation cardiotoxicity assessment.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.18
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• pp.7785-7792
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• 2014

Background: Valproic acid (VPA) is a potent anticancer and antiangiogenic agent. However, design and synthesis of chemical derivatives with improved antiangiogenic and anticancer activities are still necessary. In this study a library of novel derivatives of VPA was synthesized and tested. Methods: A human liver cancer cell line (HepG2) and a human normal embryonic kidney cell line (HEK 293) were exposed to various concentrations of VPA derivatives for 24 hours and cell viability was checked by MTT colorimetric assay. Anti-angiogenic properties were evaluated in transgenic zebrafish embryos. Results: N-valproylglycine derivatives suppressed survival almost 70% (p value 0.001) in HepG2 cells but only 10-12% in HEK 293 cells (p value 0.133). They also suppressed angiogenic blood vessel formation by 80% when used between $2-20{\mu}M$ in zebrafish embryos. Valproic acid hydrazides showed moderate level of anticancer activity by affecting 30-50% (p value 0.001) of cell viability in HepG2 cells and 8-10% in HEK293 cells (p value 0.034). Conclusion: The majority of compounds in this study showed potent and stronger antiangiogenic and anticancer activity than VPA. They proved selectively toxic to cancer cells and safer for normal cells. Moreover, these compounds inhibited developmental angiogenesis in zebrafish embryos. Based on the fact that liver is a highly vascularized organ, in case of liver carcinoma these compounds have the potential to target the pathological angiogenesis and could be an effective strategy to treat hepatocellular carcinoma.

• BMB Reports
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• v.53 no.6
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• pp.335-340
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• 2020

Since cancer is the leading cause of death worldwide, there is an urgent need to understand the mechanisms underlying cancer progression and the development of cancer inhibitors. Signal transducer and activator of transcription 3 (STAT3) is a major transcription factor that regulates the proliferation and survival of various cancer cells. Here, dual-specificity phosphatase 3 (DUSP3) was identified as a regulator of STAT3 based on an interaction screening performed using the protein tyrosine phosphatase library. DUSP3 interacted with the C-terminal domain of STAT3 and dephosphorylated p-Y705 of STAT3. In vitro dephosphorylation assay revealed that DUSP3 directly dephosphorylated p-STAT3. The suppressive effects of DUSP3 on STAT3 were evaluated by a decreased STAT3-specific promoter activity, which in turn reduced the expression of the downstream target genes of STAT3. In summary, DUSP3 downregulated the transcriptional activity of STAT3 via dephosphorylation at Y705 and also suppressed the migratory activity of cancer cells. This study demonstrated that DUSP3 inhibits interleukin 6 (IL-6)/STAT3 signaling and is expected to regulate cancer development. Novel functions of DUSP3 discovered in IL-6/STAT3 signaling regulation would help expand the understanding of cancer development mechanisms.

• Journal of Embryo Transfer
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• v.28 no.4
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• pp.343-348
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• 2013

Cell-free fetal RNA has been highlighted as useful tools for the fetal sex determination or other genetic inherent disorder. However, there is no knowledge about the sex determination using cell free fetal RNA in bovine field. Thus, the present study aimed to evaluate the presence of transcripts of DDX3Y, USP9Y and ZRSR2Y genes in maternal plasma of pregnant cows to determine the sex of the fetus using real-time quantitative polymerase chain reaction assay, and verify its accuracy, sensitivity and specificity compared with the molecular testing and the calf sex at birth. Transcripts of USP9Y and DDX3Y genes were expressed in the all plasma of males and females both the control group and the experimental group. However, ZRSR2Y gene was matched up with the molecular testing and the true sex in control group and has an overall accuracy of 82.6%, a sensitivity of 75%, and a specificity of 100% in experimental group. Therefore, these results indicated that real time PCR technique, as a noninvasive and cost-efficient method, is possible to determination fetal sex in the bovine species using circulating cell free RNA in maternal plasma and especially ZRSR2Y gene could be a good candidate for the RNA based sex determination work.

• Microbiology and Biotechnology Letters
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• v.16 no.6
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• pp.522-525
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• 1988

A method to produce tissue type Plasminogen Activator (tPA) from normal human fibroblast is developed by cultivating cells in serum free media containing heparin as an inducer. Optimal dose of this inducer was 30$\mu$g/m$\ell$. The composition of serum free medium was also defined to fit to the industrial scale cultivation. 1.42 ug of tPA per 10$^5$ viable cells per ml was produced. 1.1 gram of tPA can be produced every day from this cell line under normal perfusion chemostat operations assuming that same productivity is maintained when the process is sealed up. This method could reduce pro-duction costs and simplify purification processes by using serum free medium. Tissue type PA produced from this cell line has high ability of dissolving clots, based upon fibrin lysis test showing 50mm$^2$ of clearing zones in agarose gel plate. These results were reproducible and in good agreement with results of ELISA assay. tPA from normal human cells will be safer than that from melanoma and recombinant cells in human clinical trials.

• Korean Journal of Pharmacognosy
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• v.49 no.4
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• pp.291-297
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• 2018

Coxsackievirus B3 (CVB3) is a very well-known causative agent for viral myocarditis and meningitis in human. However, the effective vaccine and therapeutic drug are not developed yet. CVB3 infection activates host cell AKT signaling. Inhibition of AKT signaling pathway may attenuate CVB3 replication and prevent CVB3-mediate viral myocarditis. In this study, we determined antiviral effect of the selected natural plant extract to develop a therapeutic drug for CVB3 treatment. We screened several chemically extracted natural compounds by using HeLa cell-based cell survival assay. Among them, Linum usitatissimum L. extract was selected for antiviral drug candidate. L. usitatissimum extract significantly decreased CVB3 replication and cell death in CVB3 infected HeLa cells with no cytotoxicity. CVB3 protease 2A induced eIF4G1 cleavage and viral capsid protein VP1 production were dramatically decreased by L. usitatissimum extract treatment. In addition, virus positive and negative strand genome amplification were significantly decreased by 1 mg/ml L. usitatissimum extract treatment. Especially, L. usitatissimum extract was associated with inhibition of AKT signal and maintain mTOR activity. In contrast, Atg12 and LC3 expression were not changed by L. usitatissimum extract treatment. In this study, the potential AKT signal inhibitor, L. usitatissimum extract, was significantly inhibited viral genome replication and protein production by inhibition of AKT signal. These results suggested that L. usitatissimum extract is a novel therapeutic agent for treatment of CVB3-mediated diseases.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.10a
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• pp.181-181
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• 2003

We have studied the mechanism of action of TCDD on CYP1A1 promoter activity in both Hepa Ⅰ and MCF-7 cells using transient transfection system with p1A1-Luc reporter gene. When HDAC inhibitors, such as trichostatin A, HC toxin and a novel HDAC inhibitor, IN2001 were cotreated with TCDD to the cells transfected with plAt-Luc reporter gene, the basal promoter activity of CYP1A1 was increased by HBAC inhibitors. Also, in MCF-7 human breast cancer cells, HDAC inhibitors, such as IN2001 and trichostatin A increased the basal activity of CYP1A1 promoter but TCDD stimulated CYP1A1 promoter activity was not changed by HDAC inhibitors. And, in stably-transfected Hepa Ⅰ cells with p1A1-Luc, HDAC inhibitors increased the basal promoter activity only Also, we have investigated the effects of HDAC inhibitors on the human breast and prostate cancer cells in terms of cell proliferation and apoptosis based on SRB assay. IN2001 as well as trichostatin A inhibited the MCF-7, MDA-MB-231, MDA-MB-468, T47D, ZR75-1, PC3 cell growth dose-dependently. The growth inhibition of these cells with HDAC inhibitors was associated with profound morphological change, which suggests the HDAC inhibitors induced apoptosis of cells. The result of cell cycle analysis after 24h exposure of IN2001 showed G2/M cell cycle arrest in MCF-7 cells and apoptosis in T47D and MDA-MB-231 cells.

• Journal of Microbiology and Biotechnology
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• v.8 no.4
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• pp.305-309
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• 1998

The superoxide dismutase (SOD) activity of seven Bifidobacterium spp. strains was examined by an indirect SOD assay method. Some Bifidobacterium spp. showed significant levels of SOD activity. However, we could not observe any significant differences between anaerobic and aerobic cultures. Furthermore, although several Bifidobacterium spp. exhibited some degree of tolerance to paraquat which produces superoxide radicals, the apparent SOD activity of these strains was not correlated with their resistance to paraquat. In addition, when we added increasing amounts of manganese or iron to MRS medium which had been prepared without either of the metal ions, the apparent SOD activity of cell free extracts (CFEs) was increased with increasing concentration of both metal ions. To our surprise, the heat-denatured CFEs also showed nearly identical correlative patterns. Based on these results, the apparent SOD activity was likely due to a nonenzymatic dismutation. These results strongly suggest that high concentration of divalent metal ions ($Mn^{2+}$, $Fe^{2+}$) in MRS medium result in nonenzymatic dismutation which can lead to false positive SOD activities in Bifidobacerium spp.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.255.3-256
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• 2002

In the previous studies. we confirmed the anti-inflammatory components of Kalopanax pictus bark using activity-guided fractionation in vivo. For the elucidation of anti-inflammatory mechanism, we evaluated the effects of these components on the inhibition of NF-$\sub$K/B activity and human leukocyte elastase. A cell-based assay system developed in our laboratory was used in transfectant RAW 264.7 cells. (omitted)