• Asian-Australasian Journal of Animal Sciences
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• v.20 no.12
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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.

• Journal of Yeungnam Medical Science
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• v.28 no.2
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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.

• Natural Product Sciences
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• v.25 no.1
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• pp.28-33
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• 2019

A popular approach for the study of estrogen receptor ${\alpha}$ inhibition is to investigate the protein-protein interaction between the estrogen receptor (ER) and the coactivator surface. In our study, we investigated phytochemicals from Rubus coreanus that were able to disrupt $ER{\alpha}$ and coactivator interaction with an $ER{\alpha}$ antagonist. The E-screen assay and molecular docking analysis were performed to evaluate the effects of the estrogenic activity of R. coreanus extract and its constituents on the MCF-7 human breast cancer cell line. At $100{\mu}g/mL$, R. coreanus extract significantly stimulated cell proliferation ($574.57{\pm}8.56%$). Sanguiin H6, which was isolated from R. coreanus, demonstrated the strongest affinity for the $ER{\alpha}$ coactivator-binding site in molecular docking analysis, with a binding energy of -250.149. The initial results of the study indicated that sanguiin H6 contributed to the estrogenic activity of R. coreanus through the activation of the $ER{\alpha}$ coactivator-binding site.

• Applied Microscopy
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• v.39 no.1
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• pp.17-25
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• 2009

This study investigated that exposure of male mice to estrogen receptor $\alpha$-selective agonist, 4,4',4"-(4-propyl-[1H]-pyrazole-1,3,5-triyl)tris-phenol (PPT) induce morphological changes of accessory genital glands. The male reproductive organs were fixed and processed for light microscopy. The PPT induced decreases of ventral prostates, seminal vesicles and preputial glands weights with experimental time. The glandular lumen of ventral prostate was atrophied compared with control group. Type of epithelial tissues in the prostate was changed from simple columnar epithelium to stratified cuboidal or squamous epithelium. Treated group with the agonist showed that increased connective tissue underlying epithelium in the prostate and seminal vesicle. Especially, the glandular lumen of the seminal vesicle was contracted when PPT-treated animals were compared with control group. Secretion cells of preputial gland were smaller than that of control group. On week 8, PPT treatment caused decrease of epithelial cell height lining the lumen of preputial gland. These results provide information useful in researching the physiological function of estrogen mediated by estrogen receptor $\alpha$ in male accessory genital gland.

• Bulletin of the Korean Chemical Society
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• v.29 no.6
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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.

• Journal of Korean Biological Nursing Science
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• v.10 no.1
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• pp.80-87
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• 2008

Purpose: Hypoestrogenism caused by ovariectomy, disease, or menopause is associated with increased obesity in women. Altered fat distribution and weight gain are consequences of menopausal hypoestrogenism, but the mechanisms responsible are not completely known. This study examined the effect of estrogen on obesity in ovariectomized rats. Method: The groups of female rats were 4 weeks post ovariectomy (OVX) or, 4 weeks post-sham operation (SHAM), and 2 weeks post ovariectomy followed by 2 weeks replacement with estradiol benzoate (ER-$16{\mu}g$/kg, subq, qd). Serum ghrelin level was measured by radioimmunoassay (RIA). The expression of adrenergic receptors in adipose tissue was measured by Western blotting assay. Result: OVX significantly increased body weight, serum cholesterol. Two weeks estrogen replacement reduced body weight accompanied by the increment of serum ghrelin and the reduction of the receptor ratio of adrenergic ${\alpha}_{2A}/{\beta}_1$, and ${\alpha}_{2A}/{\beta}_3$. Conclusion: We provide evidence that estrogen reduces obesity through the altered receptor ratio of adrenergic ${\alpha}_{2A}/{\beta}_1$, and ${\alpha}_{2A}/{\beta}_3$ in adipose tissue in ovariectomized rats.

• Applied Microscopy
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• v.46 no.4
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• pp.193-200
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• 2016

Male reproductive organs are strongly affected by estrogen signaling mediated via the estrogen receptor. In this study, propyl pyrazole triol (PPT), an estrogen receptor alpha agonist, was subcutaneously injected in adult male mice every 2 days for a total duration of 8, 16, or 24 days. Histological changes in the reproductive organs, including the testes, efferent ductules, and epididymides, were observed. The weight of the reproductive organs decreased in the PPT group. In addition, the diameter of the seminiferous tubules decreased in the PPT group compared with the control group. The epithelial cell height decreased in the initial segment of the epididymis, whereas the luminal diameter increased in the efferent ductules of the PPT group. PPT induced irregular morphology of stereocilia in the luminal region of the initial segment. Therefore, PPT treatment at high concentrations had inhibitory effects in the reproductive organs of adult male mice. These findings suggest that short-term treatment with estrogen receptor agonist causes histological changes in the testes, efferent ductules, and epididymis, which are similar to those caused by estrogen receptor antagonist treatment. Therefore, the estrogen receptor may have functional roles in male reproductive organs, implying that treatment with an estrogen receptor agonist can affect male fertility.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.7
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• pp.4049-4052
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• 2013

Resistance to chemotherapy treatment, which may lead to limited efficacy of systemic therapy in breast cancer patients, is multifactorial. Among the mechanisms of resistance to chemotherapy treatment, there are those closely related to estrogen receptor ${\alpha}$, P-glycoprotein, multidrug resistance-related protein, glutathione S-transferase pi and topoisomerase-II. $ER{\alpha}$ is ligand-activated transcription factor that regulates gene expression and plays a critical role in endocrine signaling. In previous preclinical and clinical studies, positive $ER{\alpha}$ expression in breast cancer cells was correlated with decreased sensitivity to chemotherapy. This article reviews current knowledge on the predictive value of $ER{\alpha}$ with regard to response to chemotherapy. Better understanding of its role may facilitate patient selection of therapeutic regimens and lead to optimal clinical outcomes.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.4113-4117
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• 2012

Breast cancer is a prevalent heterogeneous malignant disease. Gene expression profiling by DNA microarray can classify breast tumors into five different molecular subtypes: luminal A, luminal B, HER-2, basal and normal-like which have differing prognosis. Recently it has been shown that immunohistochemistry (IHC) markers including estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (Her2), can divide tumors to main subtypes: luminal A (ER+; PR+/-; HER-2-), luminal B (ER+;PR+/-; HER-2+), basal-like (ER-;PR-;HER2-) and Her2+ (ER-; PR-; HER-2+). Some subtypes such as basal-like subtype have been characterized by poor prognosis and reduced overall survival. Due to the importance of the ER signaling pathway in mammary cell proliferation; it appears that epigenetic changes in the $ER{\alpha}$ gene as a central component of this pathway, may contribute to prognostic prediction. Thus this study aimed to clarify the correlation of different IHC-based subtypes of breast tumors with $ER{\alpha}$ methylation in Iranian breast cancer patients. For this purpose one hundred fresh breast tumors obtained by surgical resection underwent DNA extraction for assessment of their ER methylation status by methylation specific PCR (MSP). These tumors were classified into main subtypes according to IHC markers and data were collected on pathological features of the patients. $ER{\alpha}$ methylation was found in 25 of 28 (89.3%) basal tumors, 21 of 24 (87.5%) Her2+ tumors, 18 of 34 (52.9%) luminal A tumors and 7 of 14 (50%) luminal B tumors. A strong correlation was found between $ER{\alpha}$ methylation and poor prognosis tumor subtypes (basal and Her2+) in patients (P<0.001). Our findings show that $ER{\alpha}$ methylation is correlated with poor prognosis subtypes of breast tumors in Iranian patients and may play an important role in pathogenesis of the more aggressive breast tumors.

• Journal of the East Asian Society of Dietary Life
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• v.15 no.3
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• pp.315-322
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• 2005

In this study we report on the estrogen activity of silkworm pupa and herb extracts in vitro. The estrogenic activity of these resources was investigated by competition binding assays with estrogen receptor $\alpha(ER{\alpha})\;or\;ER{\beta}$, and viability of MCF-7 cells, a human breast cancer cell line. Saturation ligand-binding analysis of $ER{\alpha}\;and\;ER{\beta}$ revealed that all plant extracts competed with estrogen ligand for binding to both ER subtypes with a similar preference and degree and competed stronger with ligand for binding to $ER{\beta}\;than\;to\;ER{\alpha}$. The highest $ER{\alpha}-binding$ sample was silkworm pupa aqueous extract The highest $ER{\beta}-binding$ sample was silkworm pupa oil. These samples were further tested for bioactivity based on their ability to regulate cell growth rate in ER(+) breast cancer cell line, MCF-7 cells. Our studies showed that silkworm pupa, soritae, sesame, yam, pueraria, malt, ginseng, Polygonum multiflorum, and Curcuma longa significantly stimulated the growth of MCF-7 cells (P<0.05). In summary, these results suggested that silkworm pupa and herbs might be useful as potential phytoestrogens.