• 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.

• Journal of Ginseng Research
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• v.36 no.2
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• pp.169-175
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• 2012

Ginseng has been used as a traditional medicine for treatment of many diseases and for general health maintenance in people of all ages. Ginseng is also used to ameliorate menopausal systems. We investigated the estrogenic activity of Korean red ginseng (KRG) in a transient transfection system, using estrogen receptor (ER) and estrogen-responsive luciferase plasmids in MCF-7 cells. The extract activated both ER${\alpha}$ and ER${\beta}$. KRG modulated the mRNA levels of estrogen-responsive genes such as pS2 and ESR1 and decreased the protein level of ER${\alpha}$. In order to examine in vivo estrogenic activity of KRG, sixteen female Sprague-Dawley rats separated into four groups were studied for nine weeks: non-ovariectomized (OVX) rats treated with olive oil, OVX rats treated with olive oil, OVX rats treated with 17-${\beta}$-estradiol (E2) in olive oil, and OVX rats treated with KRG extract in olive oil. The experiments were repeated for three times and the data of twelve rats were combined. Body weight of OVX rats was greater than that of sham-operated control rats and was decreased by E2 treatment. Uterine weight increased after E2 treatment compared to OVX rats. However, no difference in body or uterine weight was observed with KRG intake. KRG induced reductions in total cholesterol, low density lipoprotein cholesterol/total cholesterol, high density lipoprotein cholesterol/total cholesterol, and low density lipoprotein cholesterol/high density lipoprotein cholesterol, but not to the same degree as did E2 intake. These results show that KRG does contain estrogenic activity as manifested by in vitro study but the activity is not strong enough to elicit physiological responses.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.6
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• pp.2935-2940
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• 2016

Breast cancer is the most frequent type of cancer diagnosed among women worldwide and also in Thailand. Estrogen and estrogen receptors exert important roles in its genesis and progression. Several cytokines have been reported to be involved in the microenvironment that promotes distant metastasis via modulation of immune and inflammatory responses to tumor cells. Estrogen receptor genetic polymorphisms and several cytokines have been reported to be associated with breast cancer susceptibility and aggressiveness. To investigate roles of genetic polymorphisms in estrogen receptor alpha (ESR1) and interleukin 6 (IL6), breast cancer patients and control subjects were recruited from the Division of Head, Neck and Breast Surgery (Siriraj Hospital, Bangkok, Thailand). Polymorphisms in ESR1 (rs3798577) and IL6 (rs1800795 and rs1800797) were evaluated by real-time PCR in 391 breast cancer patients and 79 healthy controls. Associations between genetic polymorphisms and clinicopathological data were determined. There was no association between genetic polymorphisms and breast cancer susceptibility. However the ESR1 rs3798577 CT genotype was associated with presence of lymphovascular invasion (OR=2.07, 95%CI 1.20-3.56, p=0.009) when compared to the TT genotype. IL6 rs1800795 CC genotype was associated with presence of extranodal extension (OR= 2.30, 95%CI 1.23-4.31, p=0.009) when compared to the GG genotype. Survival analysis showed that IL6 rs1800797 AG or AA genotypes were associated with lower disease-free survival. These findings indicate that polymorphisms in ESR1 and IL6 contribute to aggressiveness of breast cancer and may be used to identify high risk patients.

• International Journal of Oral Biology
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• v.36 no.2
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• pp.103-108
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• 2011

Measurement of estrogen concentration in bio-samples are very important for differential diagnosis of various disease or evaluation of health status. However, it is difficult to collect immediate data of estrogen concentration because they are measured by radioimmunoassay or chromatography which need time- and cost-consuming sample pre-treatment. This study was performed for development of new estrogen biosensor employing taste principles, and for evaluation of cross reactivity between various steroid hormones. Gene sequence of ligand binding domain of ${\alpha}$-human estrogen receptor (amino acid 302-553; hER-LBD) was cloned from human breast cancer cell line. The proteins of hER-LBD were produced by T7-E.coli expression system, and isolated by chromatography. hER-LBD were coated on the gold plated quartz crystal (AT-cut 9MHz), and resonance frequencies were measured by universal frequency counter. Estradiol, progesterone, testosterone, and aldosterone were used for cross reactivity of the hER-LBD. We also monitored influences of pH change in resonance frequency. The resonance frequencies of hER-LBD coated quartz crystal were decreased during increase of estrogen concentration from $15 \;{\mu}g/mL$ to $50\;{\mu}g/mL$. However, similar steroid hormones, progesterone and aldosterone, did not elicit the change in resonance frequency. Testosterone evoke weak change in resonance frequency. The new estrogen biosensor was more sensitive in pH 7.2 than in pH 7.6. These results suggest that hER-LBD coated quartz crystal biosensor is a probable estrogen biosensor.

• Molecules and Cells
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• v.27 no.3
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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.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2008.04a
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• pp.55-74
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• 2008

Previously, we have shown that hypoxia, through HIF-1, induces ligand-independent $ER{\alpha}$ activation and the physical interaction of HIF-1 and $ER{\alpha}$. However, the effect of hypoxia on the transactivation of $ER{\beta}$ is not yet known. In the present study, we found that hypoxia activated the $ER{\beta}$-mediated transcriptional response in the HEK 293 cell line, as determined by the transient expression of$ER{\beta}$ and ER-responsive reporter plasmids. The hypoxia-induced estrogen response element-mediated transcriptional response was dependent on $ER{\beta}$ expression and was inhibited by the ER antagonist ICI 182,780. Transactivation of $ER{\beta}$ was induced by the expression of HIF-$1{\alpha}$ under normoxic conditions, as determined by the expression of oxygen-independent stable GFP-HIF-$1{\alpha}$. HIF-$1{\alpha}$-induced $ER{\beta}$ transactivation was abolished by the inhibition of HIF-$1{\alpha}$ activation. This was determined by using chemical inhibitors for the MAPK pathway. In addition, HIF-$1{\alpha}$ interacted with $ER{\beta}$ in a mammalian-two hybrid assay. We conclude that hypoxia activates $ER{\beta}$ in a ligand-independent manner, possibly through the interaction of HIF-$1{\alpha}$ and $ER{\beta}$.

• Reproductive and Developmental Biology
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• v.38 no.1
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• pp.35-40
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• 2014

Beta-catenin (CTNNB1, catenin (cadherin-associated protein), beta 1) is involved in various biological processes, including embryogenesis, tumorigenesis, angiogenesis and progression of metastasis. CTNNB1, as a multifunctional and oncogenic protein, has important roles in adhesion between Sertoli cells through an N-cadherin-dependent manner and in various cancer types through its over-activation. In addition, CTNNB1 can interact with estrogen/estrogen receptor alpha complex, which regulates the transcription of WNT (wingless-type MMTV integration site family)/CTNNB1 target genes. Recently, we investigated the functional roles and expression pattern of CTNNB1 during the morphological changes of embryonic gonads of chickens and the estrogen-dependent regulation of CTNNB1 in oviduct development and potential functions as a biomarker of CTNNB1 in human epithelial ovarian cancer using the chicken as a biological research model. Therefore, in this review, we provide a new insight of potential role of CTNNB1 in the development of the female reproductive tract during early embryogenesis and ovarian carcinogenesis of laying hen models.

• 대한핵의학회:학술대회논문집
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• 2005.11a
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• pp.335.2-335.2
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• 2005

• Proceedings of the Korean Aquaculture Society Conference
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• 2004.05a
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• pp.203-204
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• 2004

• Toxicological Research
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• v.27 no.4
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• pp.253-259
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• 2011

Transforming growth factor ${\beta}$ (TGF-${\beta}$) is involved in cellular processes including growth, differentiation, apoptosis, migration, and homeostasis. Generally, TGF-${\beta}$ is the inhibitor of cell cycle progression and plays a role in enhancing the antagonistic effects of many growth factors. Unlike the antiproliferative effect of TGF-${\beta}$, E2, an endogeneous estrogen, is stimulating cell proliferation in the estrogen-dependent organs, which are mediated via the estrogen receptors, $ER{\alpha}$ and $ER{\beta}$, and may be considered as a critical risk factor in tumorigenesis of hormone-responsive cancers. Previous researches reported the cross-talk between estrogen/$ER{\alpha}$ and TGF-${\beta}$ pathway. Especially, based on the E2-mediated inhibition of TGF-${\beta}$ signaling, we examined the inhibition effect of 4-tert-octylphenol (OP) and 4-nonylphenol (NP), which are well known xenoestrogens in endocrine disrupting chemicals (EDCs), on TGF-${\beta}$ signaling via semi-quantitative reverse-transcription PCR. The treatment of E2, OP, or NP resulted in the downregulation of TGF-${\beta}$ receptor2 (TGF-${\beta}$ R2) in TGF-${\beta}$ signaling pathway. However, the expression level of TGF-${\beta}1$ and TGF-${\beta}$ receptor1 (TGF-${\beta}$ R1) genes was not altered. On the other hand, E2, OP, or NP upregulated the expression of a cell-cycle regulating gene, c-myc, which is a oncogene and a downstream target gene of TGF-${\beta}$ signaling pathway. As a result of downregulation of TGF-${\beta}$ R2 and the upregulation of c-myc, E2, OP, or NP increased cell proliferation of BG-1 ovarian cancer cells. Taken together, these results suggest that E2 and these two EDCs may mediate cancer cell proliferation by inhibiting TGF-${\beta}$ signaling via the downregulation of TGF-${\beta}$ R2 and the upregulation of c-myc oncogene. In addition, it can be inferred that these EDCs have the possibility of tumorigenesis in estrogen-responsive organs by certainly representing estrogenic effect in inhibiting TGF-${\beta}$ signaling.