• Proceedings of the Korean Society of Veterinary Pathology Conference
• /
• 2005.11a
• /
• pp.82-83
• /
• 2005

• Asian-Australasian Journal of Animal Sciences
• /
• v.23 no.3
• /
• pp.326-332
• /
• 2010

Daidzein, a natural isoflavonoid phytoestrogen, structurally resembles estradiol (E2) and possesses estrogenic activity. This study was designed to test the hypothesis that daidzein may mimic the effects of E2 on ovine follicle development by regulation of the mRNA expression of bone morphogenetic protein receptor genes and thereby influence the reproductive system. Granulosa cells were cultured in serum-free McCoy's 5A medium with and without supplementation of daidzein. Results showed that daidzein (10-100 ng/ml) significantly increased the proliferation of ovine granulosa cells (p<0.05), but inhibited the growth of granulosa cells at a dose of 1,000 ng/ml (p<0.01). Daidzein inhibited progesterone production in a dose dependent manner; however, it did not affect estradiol production by granulosa cells. We also investigated the effects of daidzein on BMPRII, BMPRIB and ALK-5 mRNA expression in ovine granulosa cells by quantitative real-time PCR. Treatment of granulosa cells with daidzein increased significantly expression of these genes at 10-100 ng/ml. Thus, these data suggested that a low concentration of daidzein (10-100 ng/ml) had a direct stimulatory effect on ovine granulosa cells while a high concentration was toxic.

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

• YAKHAK HOEJI
• /
• v.45 no.6
• /
• pp.694-700
• /
• 2001

Synthetic pyrethroids are analysis of a natural chemical moiety, pyrethrin derived from the pyrethrum plant Chrysanthemum. The natural pyrethrin structure has been modified to be highly lipophilic and photostable, creating an effective pesticide and resulting in an increased presence in the environment. Worldwide, they are commonly used insecticides against ticks, mites, mosquitoes, and as treatment for human head lice and scabies. Therefore, human exposure to their compounds in extensive. Several studies on the effects of pyrethroids on thyroid hormone regulation, estrogen and androgen function have been reported and yet little has been done try assess their potential hormonal activities. Among humans, a pyrethroid compound was suggested to be the causal agent for gynecomastia in a group of Haitian men. The reports suggest that some pyrethroid compounds are capable of disrupting endocrine function. Therefore, we examined estrogenic/antiestrogenic potential of three pyrethroid insecticides, that is permethrin, allethrin and fenvalerate in human breast cancer cell and action mechanism mediated by the estrogen receptor. Fenvalerate showed weak estrogenic activity but aallethrin and permethrin showed no effect. In combination with high levels (10$^{-10}$ M, 10$^{-11}$ M) of 17$\beta$-estradiol and three synthetic pyrethroids inhibited cert proliferations in MCF7-BUS cell by 17$\beta$-estradiol. Whereas, fenvalerate increased cell proliferative activity at lower level of estradiol (10$^{-12}$ M, 10$^{-13}$ M). The relative affinities to the estrogen receptor were observed by allethrin and permethrin treatment, but not by fenvalerate. These results indicated that some of pyrethroid insecticides may modulate estrogen functions in human breast cancer cell. The action mechanisms of estrogen receptor mediated antiestrogenicity by allethrin and permethrin were postulated.

• Journal of Marine Bioscience and Biotechnology
• /
• v.12 no.2
• /
• pp.75-80
• /
• 2020

In the present study, the estrogenic activity and anti-osteoclastogenic activity of the Myelophycus simplex extract were evaluated using T47D-Kbluc cells and bone marrow-derived macrophages (BMMs). As a result of the measurement of the estrogenic activity in the T47D-Kbluc cell line, the Myelophycus simplex extract showed increased estrogenic activity in a dose-dependent manner in association with its concentration. To confirm the regulatory effect of the Myelophycus simplex extract on the estrogen-responsive gene, the Myelophycus simplex extract showed a similar tendency to estradiol: the expression of estrogen receptor 1 (ESR1) was significantly decreased while the expression of estrogen receptor 2 (ESR2) was increased. Furthermore, the Myelophycus simplex extract exhibited an inhibitory effect on osteoclast differentiation. In conclusion, these Myelophycus simplex extracts might be regarded as candidates for further studies or the development of functional food products or medicine to prevent or avoid postmenopausal symptoms for women.

• The Korean Journal of Nuclear Medicine
• /
• v.34 no.5
• /
• pp.403-409
• /
• 2000

Objectives: Due to the heterogeneous receptor distribution and changes of receptor status over time, the biochemical measurement of estrogen receptor status of biopsy specimens is not sufficient to diagnose breast cancer. As a result, I-123 labeled estradiols have been applied for the diagnosis. The purpose of this study was to develop a suitable radioligand for imaging estrogen receptor-positive human breast tumors. Methods: Among the various estradiol derivatives, $17{\alpha}-[^{123}I]$iodovinyl estradiol ($[^{123}I]$IVE) has been prepared from $17{\alpha}$-ethynyl estradiol. Labeling of $E-17{\alpha}-[^{123}I]$iodovinyl estradiol (E-$[^{123}I]$IVE) was carried out using peracetic acid with $[^{123}I]NaI\;and\;Z-[^{123}I]IVE$ labelling was archived using chloamine-T/HCl solution with $[^{123}I]$NaI. Labeling yield was determined by silica thin-layer chromatography (TLC) and radiochemical purity was measured by high performance liquid chromatography (HPLC). The biodistribution of E-$[^{123}I]$IVE was measured in immature female rats at 60 min, 120 min and 300 min after injection. Results: The labeling yield of two isomers was 92% and 94% ($E-[^{123}I]IVE\;and\;Z-[^{123}I]IVE$, respectively). The radiochemical purity was more than 98% after purification. The highest uptake was observed at 120 min in uterus (3.11% ID/g for E-$[^{123}I]$IVE). Conclusion: These results suggest the possibility of using E-$[^{123}I]$IVE as an imaging agent for the evaluation of the evaluation of the presence of estrogen receptor in patients with breast cancer.

• Exercise Science
• /
• v.21 no.2
• /
• pp.243-254
• /
• 2012

This study tried to suggest the applicapability of soy protein supplementation and treadmill running exercise for the replacement theraphy on negative effects to estrogen metabolism in menopause. This study was analyzed the effects of 8 week soy protein supplementation and treadmill running exercise on the changes of body composition, blood concentrations of glucose, insulin, triglycerides, C-reactive protein (CRP) and estradiol, estrogen receptor gene expression of liver in ovariectomized rats. Ovariectomized groups showed the increasing responses of body weight, body fat percentage, and blood concentration of triglycerides, but these groups showed the decreasing responses of blood estradiol level and estrogen receptor gene expression in liver. Ovariectomized groups showed the positive responses of blood concentrations of lipid markers, insulin, estradiol, and estrogen receptor gene expression of liver except bone mineral contents after 8 week soy protein supplementation and treadmill running exercise. I could find the positive effects of 8 week soy protein supplementation and treadmill running exercise on the estrogen and lipid metabolism in ovariectomized rats, but this study could not confirmed the detailed replacement program of exercise intensity, duration, and soy protein volume for estrogen metabolism in ovariectomized rats.

• Korean Journal of Veterinary Research
• /
• v.37 no.2
• /
• pp.311-319
• /
• 1997

The mechanisms of $estradiol-17{\beta}$ regulating growth of both normal and neoplastic cells are not clear until now. In studies using various estrogen-dependent breast cell lines, it is recently known that estrogen controls the cell growth by regulating the expression of growth factors and/or their receptors. In the present study, we investigated the effects of $estradiol-17{\beta}$on cell growth and IGF-I binding sites using primary cultured renal proximal tubule cells. We have obtained results as follows : $Estradiol-17{\beta}(10^{-9})$ has stimulatory effects in cell growth. Cotreatment of $estradiol-17{\beta}(10^{-9}M)$ and $IGF-I(5{\times}10^{-8}M)$ significantly increased the growth of primary rabbit renal proximal tubule cells compared to that of $estradiol-17{\beta}$ or IGF-I alone treated cells. In binding studies, we found that the binding of $^{125}IGF-I$ on cell membranes was incubation time- and temperature-dependent. Incubation at $37^{\circ}C$ results in higher binding of $^{125}IGF-I$ than that of $23^{\circ}C$ or $4^{\circ}C$. Maximum binding was observed at $37^{\circ}C$ between 30 and 60 minutes. The binding of $^{125}IGF-I$ to both control and $estradiol-17{\beta}-treated$ cells was inhibited by unlabelled $IGF-I(10^{-8}{\sim}10^{-12}M)$ in a concentration-dependent manner. However, EGF did not compete for $^{125}IGF-I$ binding at $10^{-8}{\sim}10^{-12}M$. IGF-I binding to the membranes from both control and $estradiol-17{\beta}-treated$ cells was also analyzed. We found that $estradiol-17{\beta}-treated$ cells exhibited higher binding activity for IGF-I. When $estradiol-17{\beta}$ or tamoxifen alone, or $estradiol-17{\beta}$ and tamoxifen cotreated cells were compared, the binding ratio of $^{125}I-IGF-I$ of $estradiol-17{\beta}-treated$ cell was significantly increased but was similar to control in both $estradiol-17{\beta}$ and tamoxifen cotreated cell. These results suggest that $estradiol-17{\beta}$ in part controls cell proliferation by regulating the expression of IGF-I receptors in primary rabbit renal proximal tubule cells.

• Journal of Veterinary Clinics
• /
• v.18 no.4
• /
• pp.448-451
• /
• 2001

Alopecia was the main complaint in a 4 year old female Cocker spaniel dog. bilateral alopecia has been presented on skin lesion for 10 months after ovariohysterectomy about one year ago. Hyperestrogenism was diagnosed by the blood estradiol level test. Left ovarian cyst was resected in the intact ovarian position by laparotomy. Total size of the cyst was about 3 cm and it was the shape of follicular cyst. Blood estradiol level is usually higher than normal in ovarian cyst. But even though estradiol level is in normal range, dermatitis could be induced because the number of estrogen receptor of the skin would be increased or the duration of estrogen secretion would be prolonged. Because the hyperestrogenism in this case is iatrogenic, exact and proper ovariohysterectomy should be made not to induce the complications.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.8
• /
• pp.3681-3685
• /
• 2012

Background: In breast cancer, estrogen receptors have been demonstrated to interact with transcription factors to regulate target gene expression. However, high-throughput identification of the transcription regulation relationship between transcription factors and their target genes in response to estradiol is still in its infancy. Purpose: Thus, the objective of our study was to interpret the transcription regulation network of MCF7 breast cancer cells exposed to estradiol. Methods: In this work, GSE11352 microarray data were used to identify differentially expressed genes (DEGs). Results: Our results showed that the MYB (v-myb myeloblastosis viral oncogene homolog [avian]), PGR (progesterone receptor), and MYC (v-myc myelocytomatosis viral oncogene homolog [avian]) were hub nodes in our transcriptome network, which may interact with ER and, in turn, regulate target gene expression. MYB can up-regulate MCM3 (minichromosome maintenance 3) and MCM7 expression; PGR can suppress BCL2 (B-cell lymphoma 2) expression; MYC can inhibit TGFB2 (transforming growth factor, beta 2) expression. These genes are associated with breast cancer progression via cell cycling and the $TGF{\beta}$ signaling pathway. Conclusion: Analysis of transcriptional regulation may provide a better understanding of molecular mechanisms and clues to potential therapeutic targets in the treatment of breast cancer.