• Journal of Gastric Cancer
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• 제13권3호
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• pp.172-178
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• 2013

Purpose: The aims of this study were as follow: 1) to de scribe the expression status of estrogen receptor-${\alpha}$ and -${\beta}$ mRNAs in five gastric carcinoma cell lines; 2) to evaluate in vitro the effects of $17{\beta}$-estradiol and estrogen receptor antagonists on the proliferation of the cell lines. Materials and Methods: Detection of estrogen receptor-${\alpha}$ and estrogen receptor-${\beta}$ mRNA in five human gastric cancer cell lines (AGS, KATO III, MKN28, MKN45 and MKN74) was made by the reverse transcription-polymerase chain reaction system. To evaluate the effect of $17{\beta}$-estradiol and estrogen receptor antagonists on the proliferation of gastric cancer cell line, the cell lines which expressed both es trogen receptors were chosen and treated with $17{\beta}$-estradiol and estrogen receptor antagonists (methyl-piperidino-pyrazole and pyrazolo [1,5-a] pyrimidine). Cell proliferation was assessed with the methylthiazol tetrazolium test. Results: Estrogen receptor-${\alpha}$ and estrogen receptor-${\beta}$ mRNAs were expressed in three (KATO III, MKN28 and MKN45) and all of the five gastric cancer cell lines, respectively. At higher concentrations, $17{\beta}$-estradiol inhibited cell growth of MKN28, MKN45 and KATO III cell lines. Neither estrogen receptor-${\alpha}$ nor estrogen receptor-${\beta}$ antagonist blocked the anti-proliferative effect of $17{\beta}$-estradiol. Conclusions: Our results indicate that estrogen receptor-${\beta}$ mRNAs are preferentially expressed in gastric cancers and also imply that hormone therapy rather than estrogen receptor blockers may be a useful strategy for the treatment of estrogen receptor-${\beta}$ positive gastric cancer. Its therapeutic significance in gastric cancer are, however, limited until more evidence of the roles of estrogen receptors in the gastric cancer are accumulated.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2003년도 Annual Meeting of KSAP : International Symposium on Pharmaceutical and Biomedical Sciences on Obesity
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• pp.114-114
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• 2003

Ginseng is a medicinal herb widely used in Asian countries, and its pharmacological effects has been demonstrated in various systems such as cardiovascular, central nervous, and endocrine systems. Its effects are mainly attributed to the ginsenosides. We hypothesize that a component of Panax ginseng, ginsenoside-Rbl, acts by binding to estrogen receptor. We have investigated the estrogenic activity of ginsenoside-Rbl in a transient transfection system using estrogen receptors ${\alpha}$ or ${\beta}$ with estrogen -responsive luciferase plasmids in COS monkey kidney cells. Ginsenoside-Rbl activated both estrogen receptors ${\alpha}$ and ${\beta}$ in a dose-dependent manner (0.5 -100 M ). Activation was inhibited by the specific estrogen receptor antagonist ICI 182,780, indicating that the estrogenic effect of ginsenoside-Rbl is estrogen receptor dependent. Next, we evaluated the ability of ginsenoside-Rbl to induce estrogen-responsive progesterone receptor gene by semi-quantitative RT-PCR assays. MCF-7 cells treated with l7${\beta}$-estradiol or ginsenoside- Rb1 exhibited an increased expression of progesterone receptor mRNA. However, ginsenoside-Rbl failed to displace the specific binding of ［3H］17${\beta}$-estradiol to estrogen receptor in MCF-7 cells as examined by whole cell ligand binding assays, suggesting that there is no direct interaction of ginsenoside-Rbl with estrogen receptor. Our results indicate that estrogen-like activity of ginsenoside-Rbl is independent of direct estrogen receptor association.

• 한국발생생물학회지:발생과생식
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• 제11권3호
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• pp.179-185
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• 2007

Estrogen과 estrogenic endocrine disrupting chemicals(EDCs)는 주로 스테로이드 수용체와 작용하여 다양한 표적 단백질 유전자의 전사를 조절한다. 구조적으로 estrogen 수용체와 유사한 estrogen 수용체형 수용체(estrogen receptorrelated receptor, ERR)는 포유동물에서 배발생 후기에 외배엽 형성과 관련되어 있다고 알려진 고아핵수용체(orphan nuclear receptor)이다. 본 연구에서는 해양무척추동물인 둥근성게(Strongylocentrotus nudus)의 발생배를 재료로 estradiol-$17{\beta}(E_2)$과 EDCs의 일종인 nonylphenol(NP)이 발생과정의 형태학적 변화와 $ERR{\beta}$ like 1의 mRNA발현에 미치는 영향을 조사하였다. $E_2$와 NP가 처리된 발생배는 발생속도가 지연되었으며, 초기 유생기에 가까운 후기배의 비정상적인 발달형태가 관찰되었다. 수정란부터 초기 유생기까지 측정한 결과, 이들 화학물질에 의해 $ERR{\beta}$ like 1 mRNA는 포배기에 급격히 감소하는 패턴을 보였다. 이상의 결과는 둥근성게의 초기 배가 $E_2$와 NP에 의해 비정상적으로 발생되며, $ERR{\beta}$ like 1의 감소가 이 비정상적 배발생과 관련되어 있음을 시사한다.

• 한국발생생물학회지:발생과생식
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• 제11권1호
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• pp.43-47
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• 2007

Transforming growth $factor-{\beta}(TGF-{\beta})$ 신호의 매개자 역할을 하는 Smad 계열 단백질은 발생과정에 중요한 역할을 한다고 알려져 있다. Estrogen receptor(ER)와 구조적으로 유사한 estrogen receptor-related receptor(ERR)은 포유동물에서 후기 배발생기에 외배엽 형성과 관련이 되어 있는 고아핵수용체이다. 본 연구에서는 해양무척추동물의 초기발생과정과 계절번식기 동안에 Smad3와 ERR의 유전자 발현이 발생과정과 성숙에 어떠한 연관성을 갖고 있는지 알아보기 위하여, 동해안 연안에 주로 서식하는 극피동물문 둥근성게과 둥근성게(Strongylocentrotus nudus)를 재료로 하여 계절별 및 배발생 과정중에 Smad3와 $ERR{\beta}$ like 1의 mRNA 농도를 real-time PCR 방법으로 조사하였다. Smad3 mRNA는 샘플링을 시작한 2004년 2월의 생식소와 비교하면 4월부터 그 농도가 증가하기 시작하여 6월까지 증가하였으며, 산란기인 8월에 감소하였다가 10월부터 12월까지 높은 수준을 유지하였다. $ERR{\beta}$ like 1 mRNA는 6월까지 낮은 수준이었으나, 산란기인 8월에 급증한 후 다시 감소하였다. 수정란부터 초기 유생기까지 발생과정을 분석한 결과, Smad3 mRNA는 8세포기 및 16세포기에 높은 발현이 관측되었다. 한편, $ERR{\beta}$ like 1 mRNA는 포배기, 낭배기, 초기 유생기에 현저하게 높은 발현패턴을 보였다. 이상의 결과로부터 둥근성게의 산란기 및 발생배의 발생후기에 $ERR{\beta}$ like 1이 중요한 역할을 담당할 것으로 추정되며, 초기 난할시기에는 Smad3의 관련성이 시사되었다.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2002년도 추계국제학술대회
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• pp.164-164
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• 2002

에스트로젠을 처리한 송사리의 간으로부터 choriogenin vitellogenin estrogen receptor의 발현량을 전사수준에서 Real-time을 사용하여 정량.비교하였다. 시험어종으로는 부화 후 5개월 이상된 성숙한 수컷 송사리(Oryzias latipes)를(체중 약 250mg/마리)를 사용하여 17$\beta$-estradiol(25ppt, 50ppt, 100ppt)에 24시간 노출시켰다. Fluorescence dye는 choriogenin vitellogenin estrogen receptor의 경우 FAM (6-carboxyfluorescein)을 사용하였으며, $\beta$-actin의 경우는 VIC를 사용하였다. 프로브에 사용하는 quencher dye는 TAMRA(6-carboxy-N',N',N',N'-tetramethyl rhodamine)을 사용하였다. Internal control로 사용된 $\beta$-actin은 17$\beta$-estradiol의 농도에 상관 없이 0~10pM 범위에서 일정하게 발현됨을 보여주었다. vitellogenin choriogenin L 및 choriogenin H는 17$\beta$-estradiol의 농도에 의존하여 발현이 증가되는 용량-반응양상(Dose-dependent)을 나타내었다. 반면, estrogen receptor는 모든 처리군에서 $10^{-2}$pM 정도로 발혐됨에 따라 본 시험농도의 17$\beta$-estradiol에 의해서는 거의 유도발현이 되지 않음을 보여주었다. choriogenin L, choriogenin H, vitellogenin I 및 estrogen receptor 발현감수성을 비교한 결과, 25ppt 및 50ppt의 17$\beta$-esoadiol 농도에서는 ChgL > ChgH > VTG I >ER의 순으로 감수성이 높았으며, 100ppt 노출에서는 ChgL > VTG I > Chg H > ER의 순으로 감수성이 높게 나타났다. 결론적으로 choriogenin이 에스트로젠물질에 의한 가장 민감한 생체지표임을 알 수 있었다.

• Toxicological Research
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• 제20권3호
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• pp.205-211
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• 2004

Concern that some chemicals in our environment may affect human health by disrupt-ing normal endocrine function has prompted a research on interactions of environmental contaminants with steroid hormone receptor. Toxaphene and chlordane are among the 12 persistent organic pollutants identified by the United Nations Environment Programme as requiring urgent attention. We compared the estrogenic activity of two organochlorine pesticides, toxaphene and chlordane, at estrogen receptor a (ER$\alpha$) and estrogen receptor $\beta$ (ER$\beta$). Human hepatoma cells (HepG2) were transiently transfected with rat ER$\alpha$ or ER$\beta$ plus an estrogen-responsive complement C3-luciferase (C3-Luc) reporter gene. After transfection, cells were treated with various concentrations of toxaphene and chlordane to investigate agonism or antagonism of these chemicals. Both toxaphene and chlordane were potent agonists in HepG2 cells for ER$\alpha$. In contrast, these chemicals had a minimal agonist activity with ER$\beta$ and almost abolished 17$\beta$-estradiol-induced ER$\beta$-mediated activity. Therefore, toxaphene and chlordane behaved as an ER$\alpha$ agonist and an ER$\beta$ antagonist with estrogen-responsive reporter plasmid C3-Luc, and exposure to these organochlorine pesticides could have a crictical effect on normal endocrine function.

• Journal of Yeungnam Medical Science
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• 제28권2호
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• pp.153-164
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• 2011

Background: It has been reported that estrogen receptor beta ($ER{\beta}$) mRNA expression was down-regulated during carcinogenesis and was inversely related to estrogen receptor alpha ($ER{\alpha}$) expression in breast cancer. The association of $ER{\beta}$ mRNA expression to tamoxifen resistance has also been reported. In this study, the expression of $ER{\alpha}$ and $ER{\beta}$ via immunohistochemistry (IHC) and reverse transcription-polymerase chain reaction (RT-PCR) was prompted, and an attempt was made to find out the relationship between $ER{\beta}$ expression and recurrence in the hormonal therapy group, and between $ER{\beta}$ expression and known prognostic factors. Methods: Tumor specimens were obtained at surgery from 67 female breast cancer patients during the period of September 1995 to December 2000. All the specimens were frozen in liquid nitrogen and kept at $-70^{\circ}C$ until they were used. The medical records were analyzed retrospectively. The expressions of ER were analyzed using IHC and RT-PCR methods. Results: The median follow-up was at 93.0 months (range: 14-157 months). The percentage of $ER{\alpha}+/ER{\beta}+$, $ER{\alpha}+/ER{\beta}-$, $ER{\alpha}-/ER{\beta}+$, and $ER{\alpha}-/ER{\beta}$ group were 35.9% 9.4%, 47.2%, and 7.5%, respectively, in 53 patients with hormonal therapy. $ER{\beta}$ was positive in 42 (82.3%) of 51 ER-positive patients. In the hormonal therapy group, the recurrence rates of each group was 15.8%, 0%, 40.0%, and 0%, respectively. In this group, the $ER{\beta}$ expression tended to recur, but there was no clinical significance (p=0.084). Conclusion: The $ER{\beta}$ expression may be a predictive marker of a poor response to endocrine therapy in breast cancer patients, although this needs to be confirmed in additional studies.

• Asian-Australasian Journal of Animal Sciences
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• 제20권12호
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• pp.1832-1842
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• 2007

Cytochrome P450 aromatase is responsible for the biosynthesis of estrogen. It is also responsible for the endogenous production of 19-nortestosterone (nandrolone), an anabolic androgen unique to pigs. Plasma concentrations of 19-nortestosterone are highest between two and four weeks after birth in male pigs. In the present study, the physiology of 19-nortestosterone was investigated by measuring the mRNA levels of steroidogenic enzymes, estrogen receptors and androgen receptor in the tissues of growing pigs. The expression of aromatase, 17${\alpha}$-hydroxylase and 3${\beta}$-hydroxysteroid dehydrogenase in the testes of male piglets increased between birth and two weeks of age, and then decreased progressively. Similar developmental expressional patterns were observed for 17${\alpha}$-hydroxylase and 3${\beta}$-hydroxysteroid dehydrogenase in the ovaries of female piglets, but without significant aromatase expression. The major form of aromatase expressed in the testes of piglets was identified as type I. Expression of estrogen receptor-${\alpha}$ and -${\beta}$and androgen receptor genes was also detected in both testes and ovaries. A transient elevation of androgen receptor mRNA in male piglets at two weeks of age was also observed in testes. Significant expression of the androgen receptor gene, but not of estrogen receptor-${\alpha}$ and -${\beta}$ genes, was also demonstrated in adipose tissue and muscle. We conclude that the observed increase in the testicular expression of aromatase in male pigs could account for the production of large amounts of 19-nortestosterone at between two and four weeks of age in males. Androgen receptor and 19-nortestosterone appeared to be important for testicular development and might contribute to sexual dimorphism in body composition and muscle development in juvenile pigs.

• Nutritional Sciences
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• 제8권3호
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• pp.159-168
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• 2005

Phytoestrogens, especially Yak-kong or soybean-derived isoflavones have been traditionally used as a supplement of estrogen for preventing postmemopausal osteoporosis in oriental folk medicine. In our previous study, the treatment of Yak-kong and soybean increased estrogen receptor-a (ERa) expression and proliferation of MG-63 osteoblastic cells. In contrast, the increase of estrogen receptor-$\beta$ (ER$\beta$) expression in proliferating MG-63 cells with Yak-kong and soybean treatment was less pronounced, which suggested that ER$\beta$ may play a role rather in the regulation of bone cell differentiation To determine the role of ER$\beta$ in Yak-kong or soybean mediated regulation of bone cell differentiation, we established MG-63 cell lines stably expressing either ER$\beta$ or antisense ER$\beta$ RNAs. Increased expression of ER$\beta$ did not affect ERa expression and proliferation of MG-63 cells. However, increased expression of ER$\beta$ in MG-63 cells (ER$\beta$-MG63 cells) selectively enhanced Yak-kong or soybean induced expression of osteoprotegerin (OPG), a novel soluble glycoprotein which is secreted from osteoblasts and mediates the signal for osteoclast differentiation. Inhibition of ER$\beta$ expression by antisense ER$\beta$ RNAs (As-ER$\beta$-MG63) caused these cells to insensitize Yak-kong or soybean induced expression of OPG but increased MG-63 cell proliferation. Furthermore, the comparable effects between Yak-kong and the combined treatment of genistein and daidzein at $0.5{\times}l0^{-8}$ M, which is a concentration of these two isoflavones similar to Yak-kong at 0.001 mg/mL, on OPG expression in ER$\beta$-MG63 cell demonstrate that the enhanced expression of OPG with Yak-kong treatment is mediated by the synergistic effect of low leveled isoflavones in the extracts. Together, coupled with low level of ER expression in osteoclasts, our data demonstrate that ER$\beta$ in osteoblasts plays an important role in Yak-kong and soybean mediated inhibition of osteoclast differentiation indirectly by enhancing the expression of OPG.

• Bulletin of the Korean Chemical Society
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• 제29권6호
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• pp.1107-1114
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• 2008

It is important to identify selective ligands for the estrogen receptor subtypes ER$\alpha$ or ER$\beta$ to evaluate them as pharmaceutical targets in breast cancer. To develop ER$\beta$-selective ligands as PET imaging agents, a series of aryl indazole estrogen analogues substituted at the C3 position with fluoroethyl and fluoropropyl groups were synthesized and evaluated for their relative binding affinities and selectivities for ER$\alpha$ vs ER$\beta$. The fluoroethylated indazole estrogen (FEIE, 1i) and fluoropropylated indazole estrogen (FPIE, 1h) showed 41- fold and 17-fold ER$\beta$/ER$\alpha$ selectivity, respectively. However, their binding affinities to ER$\alpha$ and ER$\beta$ were very low.