• Molecules and Cells
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• 제28권1호
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• pp.67-71
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• 2009

Estrogen receptor ${\alpha}$ ($ER{\alpha}$) mediates the mitogenic effects of estrogen. $ER{\alpha}$ signaling regulates the normal growth and differentiation of mammary tissue, but uncontrolled $ER{\alpha}$ activation increases the risk to breast cancer. Estrogen binding induces ligand-dependent $ER{\alpha}$ activation, thereby facilitating $ER{\alpha}$ dimerization, promoter binding and coactivator recruitment. $ER{\alpha}$ can also be activated in a ligand-independent manner by many signaling pathways, including protein kinase A (PKA) signaling. However, in several $ER{\alpha}$-positive breast cancer cells, PKA inhibits estrogen-dependent cell growth. FoxH1 represses the transcriptional activities of estrogen receptors and androgen receptors (AR). Interestingly, FoxH1 has been found to inhibit the PKA-induced and ligand-induced activation of AR. In the present study, we examined the effects of PKA activation on the ability of FoxH1 to represses $ER{\alpha}$ transcriptional activity. We found that PKA increases the protein stability of FoxH1, and that FoxH1 inhibits PKA-induced and estradiol-induced activation of an estrogen response element (ERE). Furthermore, in MCF7 cells, FoxH1 knockdown increased the PKA-induced and estradiol-induced activation of the ERE. These results suggest that PKA can negatively regulate $ER{\alpha}$, at least in part, through FoxH1.

• 한국환경성돌연변이발암원학회지
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• 제24권4호
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• pp.163-170
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• 2004

CYP1B1 enzyme metabolize PAHs and estradiol. CYP1B1 metabolize estradiol to 4-hydroxyestradiol that is considered as carcinogenic metabolite. Luciferase activity was induced about 20 folds over that control by 1 nM TCDD (2,3,7,8-tetrchlorodibenzo-p-dioxin) and these inductions were dose-dependent. Recent industrialized society, human hasbeen widely been exposed to widespread environmental contaminants such as PAHs (polycyclic aromatic hydrocarbon) that are originated from the incomplete combustion of hydrocarbons. PAHs are known to be ligands of the AhR (aryl hydrocarbon receptor). Induction of cytochrome P4501B1(CYP1B1) in cell culture is widely used as a biomarket for PAHs. Therefore we have studied the effect of PAHs in the human breast cancer cells MCF-7 to evaluate bioactivity of PAHs. Cytochrome P4501B1(CYP1B1) is known to be inducible by xenobiotic compounda such as policyclic aromatic hydrocarbon (PAH) and dioxins such as 2,3,7,8-tetrachloro-dibenzo-p-dioxin(TCDD). And these induction of CYP1B1 is also regulated by many categories of chemicals. In order to investigate the effects of several chemicals on CYP1B1 gene expression in luciferase gene, and then transfected into these cells. After treatment of chemicals, the luciferase activity was measured. We examined effects of PAHs on the CYP1B1-lucifrease reporter gene and CYP1B1 mRNA level. Benzo(k)fluoranthene showed strong response to CYP1B1 promoter activity stimulation, and also CYP1B1 mRNAs increase in MCF-7 cells in a concentration-dependent manner. flvonoids such as genistein decreased B(k)F induced luciferase activity at low concentration. it exhibited stimulatory effect at high concentration.

• 약학회지
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• 제41권6호
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• pp.718-723
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• 1997

In the course of developing novel antitumor intercalating agents, we synthesized 3- carbamoyloxymethyl-azaanthraquinones 6-12, incorporating the latent alkylating functionality. These compounds were designed to explore the effect of heteroatom incorporation into anthraquinone chromophore and the effect of the incorporation of the latent alkylating functionality. The derivatives were prepared by hetero Diels-Alder reaction as a key step followed by functionality of allylic methyl to the desired substituents. Growth inhibitory studies of the azaanthraquinones were conducted in vitro against human cancer cell lines (SNU-354: liver and MCF7: breast) and human epidermoid carcinoma cells that are sensitive (KB-3-1) and multidrug-resistant (KB-V-1). The derivatives were 10 to 100-fold less potent than doxorubicin against sensitive cell lines. However, they were marginally cross-resistant with doxorubicin against KB-V-1.

• Journal of Microbiology and Biotechnology
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• 제10권3호
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• pp.293-299
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• 2000

Many methods have been developed for screening chemicals with hormonal activity. Using recombinant yeasts expressing either human estrogen receptor [Saccharomyces cerevisiae ER + LYS 8127 (YER)] or androgen receptor [S. cerevisiae AR + 8320 (YAR)], we evaluated the hormonal activities of several chemicals by induction of ${\beta}-galactosidase$ activity. The chemicals were $17{\beta}-estradiol$ (E2), testosterone (T), ${\rho}-nonylphenol$ (NP), bisphenol A (BPA), genistein (GEN), 2-bromopropane (2-BP), dibutyl phthalate (DBP), di-(2-ethylhexyl) phthalate (DEHP), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and butylparaben (BP). To assess the estrogenicity of NP, the result of the in vitro recombinant yeast assay was compared with an E-screen assay using MCF-7 human breast cancer cells and an uterotrophid assay using ovariectomized mice. In the YER yeast cells, E2, NP, BPA, GEN, and BP exhibited estrogenicity in a doseresponse manner, while TCDD did not. All the chemicals tested, except T, did not show androgenicity in the YAR yeast cell. The sensitivity of the yeast (YER) assay system to the estrogenic effect of NP was similar to that of the E-screen assay. NP was also estrogenic in the uterotrophic assay. However, in terms of convenience and costs, the yeast assay was superior to the E-screen assay or uterotrophic assay. These results suggest that the recombinant yeast assay can be used as a rapid tool for detecting chemicals with hormonal activities.

• 한국환경성돌연변이발암원학회지
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• 제24권4호
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• pp.198-205
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• 2004

Cytochrome P4501B1(CYP1B1) is known to be inducible by xenobiotic compounds such as policyclic aromatic hydrocarbon(PAH) and dioxins such as 2,3,7,8-tetrachloro-dibenzo-p-dioxin(TCDD). And these induction of CYP1B1 is also regulated by many categories of chemicals. In order to investigate the effects of several chemicals on CYP1B1 gene expression in Hepa-I and MCF-7 cells, 5' flanking DNA of human CYP1B1 was cloned into pGL3 basic vector containing luciferase gene, and then transfected into these cells. After treatment of chemicals, the luciferase activity was measured. CYP1B1 enzyme metabolize PAHs and estradiol. CYP1B1 metabolize estradiol to 4-hydrozyestradiol that is considered as carcinogenic metabolite. Recent industrialized industrialized society, human has been widely been exposed to widespread environmental contaminants such as PAHs(polycyclic aromatic hydrocarbon) that are originated from the imcomplete combustion of hydrocarbons. PAHs are known to be ligands of the AhR(aryl hydrocarbon receptor). Induction of cytochrome P4501B1(CYP1B1) in cell culture is widely used as a biomarker for PAHs. Therefore we have studied the effect of PAHs in the human breast cancer cells MCF-7 to evaluate bioactivity of PAHs. We have used the United State of America EPA selected 13 different PAHs, PAHs mixtures and extracts from environmental samples to evaluate the bioassay system. We examined effects of PAHs on the CYP1B1-luciferase reporter gene and CYP1B1 mRNA level. Benzo(k)fluoranthene and dibenzo(a, h)anthracene showed strong response to CYP1B1 promoter activity stimulation, and also CYP1B1 mRNAs increase in MCF-7 cells in a concentration-dependent manner. RT-PCR analysis indicated that PAHs significantly up-regulate the level of CYP1B1 mRNA. Some flavonoids such as genistein, daidzein, chrysin, naringenin and morin were also investigeted. These flavonoids decreased B(k)F infuced luciferase activity at low concentration. But, these flavonoids exhibited stimulatory effect at high concentration.

• 한국식품과학회지
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• 제30권1호
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• pp.213-217
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• 1998

곰솔, 리기다, 잣나무, 적송잎의 에탄올 추출물들은 농도가 증가함에 따라 폐암, 간암, 위암, 유방암 세포에 대한 성장억제율이 증가함을 보여 주였고 각각의 디에틸에테르, 클로로포름, 에틸 아세테이트, 부탄올 및 수층 분획물 또한 농도 증가에 따라 성장 억제율이 증가하였다. 그러나 0.25 mg/mL 처리시 각각의 비교 결과 잣나무의 디에틸에테르 분획물은 위암세포에 대해서는 억제효과가 보여지지 않았다. 현미경의 관찰하에서 암세포의 변화는 세포막의 경계가 흐트러지는 사멸 현상을 보였다.

• 한국식품영양과학회지
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• 제30권5호
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• pp.921-927
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• 2001

각종 암세포에 대한 번데기동충하초(Cordyceps militaris) 추출물 및 분획물의 세포독성을 규명하기 위하여 암세포로 A549, MCF-7 HeLA, HT1080, Hep3B, KATOIII 및 K562를 이용하였고 그 결과, SRB assay에 의한 1 mg/mL의 에탄올 추출물 농도에서 HT1080, HeLa, Jep3B 그리고 A549는 각각 89.4%, 85.7%, 72.9%그리고 65.5%의 억제효과를 나타내었다. MCF7, HeLa 그리고 HT1080 세포의 경우는 핵산 분획물 1 mg/mL 농도에서 각각 92.9%, 90.3%그리고 97.0%로 다른 분획물보다 현전히 높은 억제효과를 나타냈다. KATOIII세포에 대한 억제효과는 1mg/mL 투여시 에탄올 추출물의 경우 61.5%를 보였고 부탄올과 물 분획물에서 각각 83.7%와 80.4%로 다소 높은 억제효과를 보였다. K562 세포에 대한 시료의 억제효과는 에탄올 추출물(1mg/mL)이 60.5%의 억제율을 보인데 반해 같은 농도에 서 에틸 아세테이트, 부탄올 및 핵산 분획물에서는 각각 88.6%, 806% 및 75.6%로 높은 억제 효과는 양성대조군의 11.2$\pm$0.8에 비하여 10, 20, 40, 80 mg/kg 의 농도에 10.5$\pm$0.8, 8.3$\pm$0.5, 7.8$\pm$0.3, 3.7$\pm$0.6로 8.7, 25.9, 30.4그리고 67.0%의 유의적인 억제효과를 나타내었다. 또한 각각의 분획물에 대한 소핵생성 억제효과는 유전손상물질(MNNG;150 mg/kg, I.P)만 투여한 양성대조군에 비해서 시료 농도를 10, 20, 40 80 mg/kg 처리하였을 경우 동이라한 시료 농도 80 mg/kg 에서 부탄올, 에틸 아세테이트, 물, 그리고 클로로포름 분획물이 각각 3.1$\pm$0.3, 3.7$\pm$0.6, 4.2$\pm$0.3, 4.8$\pm$0.3으로 72.3%, 67.0%, 63.3%그리고 57.1%의 순으로 소핵생성 억제효과를 나타내었으며, 그중 핵산 분획물이 2.8$\pm$0.5의 75.0%로 가장 높은 소핵생성 억제효과를 나타내었다.

• 한국축산식품학회지
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• 제32권5호
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• pp.612-617
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• 2012

The antioxidant, antimicrobial, and cytotoxic activities of ovotransferrin were investigated in vitro. The antioxidant capacity of ovotransferrin was evaluated using the 2,2-Diphenyl-1-picryl hydrazyl (DPPH) radical scavenging method, antimicrobial effects using the agar well diffusion method, and cytotoxicity using the 3-(4,5-dimethylthizol-2-yl)-2,5-diphenylatetetrazolium bromide (MTT) assay. The DPPH radical-scavenging capacity of ovotransferrin at 1 mg/mL level reached approximately 60% after 48 h of reaction. The antimicrobial effects of ovotransferrin against common food-borne pathogens, Staphylococcus aureus KCCM 32395, Bacillus cereus KCCM 40935, Listeria monocytogenes ATCC 15313, Escherichia coli O157:H7 ATCC 43895, and Helicobacter pylori HpKCTC 26695 were dose dependant. Gram-positive bacteria was more sensitive to ovotransferrin than gram-negative bacteria. Ovotransferrin showed stronger antimicrobial effect against L. monocytogenes than other gram-positive bacteria tested. The cytotoxicity of ovotransferrin was evaluated in human cancer cell lines, various tissue origins, including the larynx (Hep-2), stomach (AGS), lung (SK-MES-1), liver (HepG2), breast (MCF-7), cervix (HeLa), and colon (HT-29). Ovotransferrin displayed relatively high cytotoxicity (${\leq}60%$ inhibition effects) at 40 mg/mL. At lower concentrations (${\leq}10mg/mL$), however, ovotransferrin cytotoxic effects were not significant in all cancer cell lines tested. These results indicated that ovotransferrin has potential to be used as an antioxidant or antimicrobial agent in foods or a pharmaceutical agent against cancers.

• Journal of Microbiology and Biotechnology
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• 제32권5호
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• pp.551-563
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• 2022

L-asparaginase (E.C. 3.5.1.1) purified from bacterial cells is widely used in the food industry, as well as in the treatment of childhood acute lymphoblastic leukemia. In the present study, the Burkholderia pseudomallei L-asparaginase gene was cloned into the pGEX-2T DNA plasmid, expressed in E. coli BL21 (DE3) pLysS, and purified to homogeneity using Glutathione Sepharose chromatography with 7.26 purification fold and 16.01% recovery. The purified enzyme exhibited a molecular weight of ~33.6 kDa with SDS-PAGE and showed maximal activity at 50℃ and pH 8.0. It retained 95.1, 89.6%, and 70.2% initial activity after 60 min at 30℃, 40℃, and 50℃, respectively. The enzyme reserved its activity at 30℃ and 37℃ up to 24 h. The enzyme had optimum pH of 8 and reserved 50% activity up to 24 h. The recombinant enzyme showed the highest substrate specificity towards L-asparaginase substrate, while no detectable specificity was observed for L-glutamine, urea, and acrylamide at 10 mM concentration. THP-1, a human leukemia cell line, displayed significant morphological alterations after being treated with recombinant L-asparaginase and the IC₅₀ of the purified enzyme was recorded as 0.8 IU. Furthermore, the purified recombinant Lasparaginase improved cytotoxicity in liver cancer HepG2 and breast cancer MCF-7 cell lines, with IC₅₀ values of 1.53 and 18 IU, respectively.

• Molecules and Cells
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• 제27권3호
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• pp.351-357
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• 2009

Phytoestrogens are the natural compounds isolated from plants, which are structurally similar to animal estrogen, $17{\beta}$-estradiol. Tectoridin, a major isoflavone isolated from the rhizome of Belamcanda chinensis. Tectoridin is known as a phytoestrogen, however, the molecular mechanisms underlying its estrogenic effect are remained unclear. In this study we investigated the estrogenic signaling triggered by tectoridin as compared to a famous phytoestrogen, genistein in MCF-7 human breast cancer cells. Tectoridin scarcely binds to ER ${\alpha}$ as compared to $17{\beta}$-estradiol and genistein. Despite poor binding to ER ${\alpha}$, tectoridin induced potent estrogenic effects, namely recovery of the population of cells in the S-phase after serum starvation, transactivation of the estrogen response element, and induction of MCF-7 cell proliferation. The tectoridin-induced estrogenic effect was severely abrogated by treatment with U0126, a specific MEK1/2 inhibitor. Tectoridin promoted phosphorylation of ERK1/2, but did not affect phosphorylation of ER ${\alpha}$ at $Ser^{118}$. It also increased cellular accumulation of cAMP, a hallmark of GPR30-mediated estrogen signaling. These data imply that tectoridin exerts its estrogenic effect mainly via the GPR30 and ERK-mediated rapid nongenomic estrogen signaling pathway. This property of tectoridin sets it aside from genistein where it exerts the estrogenic effects via both an ER-dependent genomic pathway and a GPR30-dependent nongenomic pathway.