• Proceedings of the Korean Society of Applied Pharmacology
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• 2001.11a
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• pp.112-112
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• 2001

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is an environmental toxin that activates the aryl hydrocarbon receptor (AhR) and disrupts multiple endocrine signaling pathways by enhancing ligand metabolism, altering hormone synthesis, down regulating receptor levels, and interfering with gene transcription. And TCDD-mediated gene transactivation via the AhR has been shown to be dependent upon estrogen receptor (ER) expression in human breast cancer cells. In the present study, we have examined the effect of natural estrogen, phytoestrognes and environmental estrogens on the regulation of CYP1A1 gene expression in MCF-7 human breast cancer cell line. that ER and AhR are co-expressed. pCYP1A1 -luc reporter gene was transiently transfected into MCF-7 cells. These cells were treated with various chemicals and then luciferase assay was carried out. 17be1a-estradiol significantly inhibited TCDD stimulated luciferase activity dose dependently and this inhibition was partially recovered by concomitant treatment of tamoxifen. 17beta-estradiol metabolites, 2-hydroxyestradiol and 16alpha-estriol resulted in less potent inhibitory effect than estradiol and synthetic estrogen, diethylstilbestrol (DES) showed no effect on CYP1A1 gene expression. This study demonstrated that estrogen down-regulated TCDD stimulated CYP1A1 expression via ER mediation. And we have found out that several flavonoids such as genistein, kaempferol, daidzein, naringenin, and alkylphenols such as nonylphenol, 4-octylphenol and resveratrol also inhibited TCDD induced CYP1A1 expression like estrogen.

• Molecular & Cellular Toxicology
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• v.5 no.1
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• pp.67-74
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• 2009

Exposures to environmental chemicals that mimic endogenous hormones are proposed for a number of adverse health effects, including infertility, abnormal prenatal and childhood development and above all cancers. In addition, recently miRNA (micro RNA) has been recognized to play an important role in various diseases and in cellular and molecular responses to toxicants. In this study, endocrine disrupting environmental toxicant, nonylphenol (NP) was treated to MCF-7 (Human breast cancer cell) and HepG2 (Human hepatocellular liver carcinoma) cell line at 3 hrs and 48 hrs time point and miRNA analysis using $mirVana^{TM}$ miRNA bioarray was performed and compared with total mRNA microarray data for the same cell line and treatment. Robust data quality was achieved through the use of dye-swap. Analysis of microarray data identifies a total of 20 and 11 miRNA expressions at 3 hrs and 48 hrs exposure to NP in MCF-7 cell line and a total of 14 and 47 miRNA expression at 3 hrs and 48 hrs exposure respectively to NP in HepG2 cell line. Expression profiling of the selected miRNA (let-7c, miR-16, miR-195, miR-200b, miR200c, miR-205, and miR-589) reveals changes in the expression of target genes related to metabolism, immune response, apoptosis, and cell differentiation. The present study can be informative and helpful to understand the role of miRNA in molecular mechanism of chemical toxicity and their influence on hormone dependent disease. Also this study may prove to be a valuable tool for screening potential estrogen mimicking pollutants in the environment.

• BMB Reports
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• v.43 no.1
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• pp.9-16
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• 2010

The promoters of OsCaM1 and OsCaM3 were characterized after sequencing and fused to the reporter gene, GUS. The constructs were then transformed into the tobacco plant. Histochemical analysis of GUS showed different expression patterns in pOsCaM1::GUS and pOsCaM3:: GUS transgenic plants. The expression of pOsCaM1::GUS in 4- to 15-day-old seedlings in particular was observed only in the root, while the expression of pOsCaM3::GUS was detected in both the cotyledons and root. Also, pRCaM1::GUS was detected in all the tissues surrounding the root system, while the presence of pOsCaM3::GUS was observed in the root, except in the root meristem. However, in mature transgenic plants, the expression of pOsCaM1::GUS and OsRCaM3::GUS was scarcely detected. Under wounding stress, the GUS activity of pOsCaM1 and pOsCaM3 was strongly induced, and the activity of pOsCaM3 especially, was retained for long periods. In the phloem, pOsCaM3 activity induced by hormone treatments and abiotic stresses was also identified.

• Korean Journal of Environmental Biology
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• v.25 no.4
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• pp.378-384
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• 2007

Some of ecological factors and the early life history of endangered freshwater fish, Pseusobagrus brevicorpus, were investigated to proliferate artificially and to restore the population by release seedlings. The density of population in restricted area by small scale dam was 1.25 ind. $m^{-2}$, and the low capacity for reproduction having 200$\sim$250 eggs ind$^{-1}$. were thought to be a reason of this endangered situation. From the result of induction of natural spawning in aquarium after hormone injection it was considered that the spawning substrate would be aquatic plants with slender branches. The hatching was observed after 50 hrs after fertilization and the larvae showed aggressive behavior. Yolk was almost absorbed 3 days after hatching, and the larvae shaped tad-pole grew up to fry after 30 days. We discussed on the strategies for conservation of this species according to those results from investigation on ecology and early life history.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2002.11a
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• pp.123-126
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• 2002

Pollutants that are persistent, bioaccurnulative, and toxic have been linked to numerous adverse effects in human and animals, PBTs include heavy metals, polychlorinated biphenyls (PCBs), dioxins, polycyclic aromatic compounds (PACs) in addition to pesticides. This study focuses on toxic effects of the PBTs except pesticides on insects. Eight PBTs were selected from subgroups: three heavy metals (Pb, Hg, and Cd), two PCB mixtures (Aroclor mixtures 1 and 2), 2,3,7,8-tetrachlorodibenzo-p-dioxin, two monophenols (4-octylphenol and 4-nonylphenol), and tetrabutyltin, Beet armyworm, Spodoptera exigua, was used as test target insect species. Three physiological markers (metamorphosis, immune reaction, and follicle patency) were assessed in each exposure to different doses of the PCBs. Heat-shock proteins as molecular markers were also analyzed in response to the PCBs. All tested PBTs were toxic to metamorphosis from larvae to pupae when they were applied with diet. Two PCB mixtures were the most toxic compounds in this assay by giving significant toxicity at 0.005 ppm, while others had from 10 to 1000 ppm. Dioxin (0.1 ppb), tetrabutyltin (0.1 ppb), Pb (10 ppb), and Hg (0,01 ppb) were potent to inhibit immune reactions analyzed by inducing phenoloxidase activity and blocked phospholipase $A_2$ enzyme, Tetrabutyltin and dioxin significantly induced follicle cell patency, but their effects were lower than that of endogenous juvenile hormone, Dioxin, Pb, Hg, and Cd could induce the expression of heat shock proteins that were detected by immunoblotting against human HSP70 monoclonal antibody. HSP78 and HSP80 were upregulated in response to the PBTs. This expression was detected from the fat body and epidermis at as fast as 4h after injection. All these results clearly suggest that PBTs give significant ecotoxicity to insects that are valuable organisms in our environment.

• Journal of Ginseng Research
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• v.36 no.4
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• pp.449-460
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• 2012

Plants have versatile detoxification systems to encounter the phytotoxicity of the wide range of natural and synthetic compounds present in the environment. Glutathione S-transferase (GST) is an enzyme that detoxifies natural and exogenous toxic compounds by conjugation with glutathione (GSH). Recently, several roles of GST giving stress tolerance in plants have demonstrated, but little is known about the role of ginseng GSTs. Therefore, this work aimed to provide further information on the GST gene present in Panax ginseng genome as well as its expression and function. A GST cDNA (PgGST) was isolated from P. ginseng cDNA library, and it showed the amino acid sequence similarity with theta type of GSTs. PgGST in ginseng plant was induced by exposure to metals, plant hormone, heavy metals, and high light irradiance. To improve the resistance against environmental stresses, full-length cDNA of PgGST was introduced into Nicotiana tabacum. Overexpression of PgGST led to twofold increase in GST-specific activity compared to the non-transgenic plants, and the GST overexpressed plant showed resistance against herbicide phosphinothricin. The results suggested that the PgGST isolated from ginseng might have a role in the protection mechanism against toxic materials such as heavy metals and herbicides.

• Environmental Analysis Health and Toxicology
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• v.27
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• pp.10.1-10.7
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• 2012

Objectives: In recent years, a number of structurally diverse Histone deacetylase (HDAC) inhibitors have been identified and these HDAC inhibitors induce growth arrest, differentiation and/or apoptosis of cancer cells in vitro and in vivo. This study aimed at investigating the antitumor activity of newly synthesized HDAC inhibitor, 3-(4-dimethylamino phenyl)-N-hydroxy-2-propenamide (IN-2001) using human breast cancer cells. Methods: We have synthesized a new HDAC inhibitor, IN-2001, and cell proliferation inhibition assay with this chemical in estrogen receptor-positive human breast cancer MCF-7 cells. Cell cycle analysis on MCF-7 cells treated with IN-2001 was carried out by flow cytometry and gene expression was measured by RT-PCR. Results: In MCF-7 cells IN-2001 showed remarkable anti-proliferative effects in a dose- and time-dependent manner. In MCF-7 cells, IN-2001 showed a more potent growth inhibitory effect than that of suberoylanilide hydroxamic acid. These growth inhibitory effects were related to the cell cycle arrest and induction of apoptosis. IN-2001 showed accumulation of cells at $G_2$/M phase and of the sub-$G_1$ population in a time-dependent manner, representing apoptotic cells. IN-2001-mediated cell cycle arrest was associated with HDAC inhibitor-mediated induction of CDK inhibitor expression. In MCF-7 cells, IN-2001 significantly increased $p21^{WAF1}$ expression. Conclusions: In summary, cyclin-dependent kinase (CDK) induced growth inhibition, possibly through modulation of cell cycle and apoptosis regulatory proteins, such as CDK inhibitors, and cyclins. Taken together, these results provide an insight into the utility of HDAC inhibitors as a novel chemotherapeutic regime for hormone-sensitive and insensitive breast cancer.

• Applied Biological Chemistry
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• v.49 no.3
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• pp.196-201
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• 2006

Vitellogenin, which is found in the serum of female and male fishes exposed to environmental endocrine disrupter or estrogen hormone, is used as a biomarker for environmental contamination with an endocrine disrupter. In order to produce antibody against vitellogenin, a synthetic peptide for partial vitellogenin was injected into rabbits. In addition, by using ion exchange chromatography on DE-52, vitellogenin was purified from the serum of carp induced with $17{\beta}$-estradiol. Polyclonal antibody against purified vitellogenin reacted well with vitellogenin in the serum of carp induced with $17{\beta}$-estradiol and the serum of female carp, whereas polyclonal antibody against the vitellogenin peptide did not react with proteins in those samples. This may indicate that vitellogenin proteins, covalently modified largely, could not be detected by Western blotting with the polyclonal antibody against the synthetic vitellogenin peptide.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.866-871
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• 2011

An auxin-producing bacteria (3YN11-02) was isolated from waste mushroom bed from Agaricus bisporus of Chungnam Buyeo-Gun area. The strain 3YN11-02 was identified as a novel species belongs to Rahnella aquatica by a chemotaxanomic and phylogenetic nalysis. The isolate was confirmed to produce indole-3-acetic acid (IAA) which is one of auxin hormone by TLC and HPLC analysis. When the concentration of IAA was assessed by performing HPLC quantity analysis, the maximal $290mg\;L^{-1}$ of IAA detected in ether fraction extracted from the culture filtrate which was cultured in R2A broth containing 0.1% tryptophan for 24 h at $35^{\circ}C$. The molecular weight of the main peak obtained by LC-mass analysis was correspondent well to 175, that of IAA. To investigate the growth promoting effect of crop, when the culture broth of R. aquatica 3YN11-02 was infected onto water culture and seed pot of mung bean, the adventitious root induction and root growth of mung bean were 2.0 times higher than control.

• BMB Reports
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• v.52 no.11
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• pp.647-652
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• 2019

G protein-coupled estrogen receptor (GPER) is known to play an important role in hormone-associated cancers. G-1, a novel synthetic GPER agonist, has been reported to exhibit anti-carcinogenic properties. However, the chemotherapeutic mechanism of GPER is yet unclear. Here, we evaluated GPER expression in human gastric cancer tissues and cells. We found that G-1 treatment attenuates GPER expression in gastric cancer. GPER expression increased G-1-induced antitumor effects in mouse xenograft model. We analyzed the effects of knockdown/overexpression of GPER on G-1-induced cell death in cancer cells. Increased GPER expression in human gastric cancer cells increased G-1-induced cell death via increased levels of cleaved caspase-3, -9, and cleaved poly ADP-ribose polymerase. Interestingly, during G-1-induced cell death, GPER mRNA and protein expression was attenuated and associated with ER stress-induced expression of PERK, ATF-4, GRP-78, and CHOP. Furthermore, PERK-dependent induction of ER stress activation increased G-1-induced cell death, whereas PERK silencing decreased cell death and increased drug sensitivity. Taken together, the data suggest that the induction of ER stress via GPER expression may increase G-1-induced cell death in gastric cancer cells. These results may contribute to a new paradigm shift in gastric cancer therapy.