• BMB Reports
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• v.44 no.7
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• pp.423-434
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• 2011

A female hormone, estrogen, is linked to breast cancer incidence. Estrogens undergo phase I and II metabolism by which they are biotransformed into genotoxic catechol estrogen metabolites and conjugate metabolites are produced for excretion or accumulation. The molecular mechanisms underlying estrogen-mediated mammary carcinogenesis remain unclear. Cell proliferation through activation of estrogen receptor (ER) by its agonist ligands and is clearly considered as one of carcinogenic mechanisms. Recent studies have proposed that reactive oxygen species generated from estrogen or estrogen metabolites are attributed to genotoxic effects and signal transduction through influencing redox sensitive transcription factors resulting in cell transformation, cell cycle, migration, and invasion of the breast cancer. Conjuguation metabolic pathway is thought to protect cells from genotoxic and cytotoxic effects by catechol estrogen metabolites. However, methoxylated catechol estrogens have been shown to induce ER-mediated signaling pathways, implying that conjugation is not a simply detoxification pathway. Dual action of catechol estrogen metabolites in mammary carcinogenesis as the ER-signaling molecules and chemical carcinogen will be discussed in this review.

• Clinical and Experimental Reproductive Medicine
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• v.29 no.4
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• pp.279-285
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• 2002

Objective : To evaluate the difference between estrogen only therapy and estrogen-androgen combination therapy in surgical menopause patients. Materials and Method: Surgical menopause patients received 0.625 mg conjugated equine estrogens or 0.625 mg conjugated equine estrogens plus 1.25 mg methyltestosterone for 2 years. Bone mineral density, menopausal symptoms, lipoprotein profiles were measured. Results: Both groups showed increased bone mineral density. In the combination group, total cholestero l, high density lipoprotein cholesterol and triglycerides decreased. In the estrogen only group, low density lipoprotein cholesterol decreased but high density lipoprotein cholesterol increased significantly. In both groups, menopausal symptoms were much improved. Side effects were easily tolerated in both groups. Conclusions: Estrogen-androgen combination therapy had comparable benefits compared with estrogen only therapy.

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.10b
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• pp.182-182
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• 2003

cResveratrol (3,5,4'-trihydroxystilbene), a naturally occurring phytoalexin present in grapes and other foods, has been well documented for chemopreventive effects in different systems based on its striking inhibition of diverse cellular events associated with tumor initiation, promotion and progression.(omitted)

• Journal of Applied Biological Chemistry
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• v.51 no.1
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• pp.1-6
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• 2008

Estrogens, a group of steroid compounds functioning as the primary female sex hormone, play an important role in the development and progression of breast cancer. In this study, using a novel annealing control primer-based GeneFishing PCR technology, five differentially expressed genes (DEGs), expressed using 10nM mitogenic estrogens, $17{\beta}$-estradiol (E2) and $16{\alpha}$-hydroxyestrone ($16{\alpha}$-OHE1), were selected from the estrogen receptor (ER)-positive MCF-7 human breast cancer cells. The DEGs, MRPL42, TUBA1B, SSBP1, KNCT2, and RUVBL1, were identified by comparison with the known genes via direct sequencing and sequence homology search in BLAST. Quantitative real-time PCR data showed that two DEGs, tubulin ${\alpha}1b$ and kinetochore associated 2, were greater than 2-fold upregulated by E2 or $16{\alpha}$-OHE1. Both genes could be new biomarkers for the treatment and prognosis of cancers, and further study may provide insights into the molecular mechanisms underlying development and progression of breast cancer.

• Journal of Food Hygiene and Safety
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• v.9 no.1
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• pp.1-13
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• 1994

A Simultaneous determination method was improved for the determination and confirmation of zeranol, zearalenone, as well as their isomers and metabolites, in beef. The analytes were extracted from tissue by CH3CN, hydrolyzed enzymatically(for glucuronide conjugates), cleaned up by a strong basic anion exchange resin combined with a liquid/liquid partitioning, derivatized using MSTFA and confirmed, quantified by GC/MS/SIM with a internal standard, zearalane. The results were as follows : (1) all the estrogens were separated on the GC/MS chromatogram under the extraction method and the chromatographic conditions improved, the retention times of zearalane-TMS2, zearalanone-TMS2, zearalenone-TMS2, zeranol-TMS3, taleranol-TMS3, and $\alpha$-zearalenol-TMS3, $\beta$-zearalenol-TMS3, were 18.49, 19.44, 19.63, 19.71, 19.79 and 19.99, 20.08 minutes, respectively. (2) The calibration curves of residual zeranol, zearalenone and their metabolites showed constantly linear(r=0.99) in the range of 5~20 ng. The minimum detection concentration of residual zeranol, zearalenone and their metabolites was 1 ppb. (3) The total average recovery of residual zeranol, zearalenone and their metabolites from spiked beef was 60.2%(CV=29.7%) at the 1 ppb and 63.5%(CV=26.5) at the 2 ppb, 72.9%(CV=18.2%) at the 4 ppb. (4) The preservation method for 6 estrogens was improved for the fast running time(21 min) and MSTFA was utilized for derivatizing 6 estrogens for improvement of recovery, for good resolution, for characteristic mass spectra unlike Jose's method and Tina's method. The utilization of zearalane as internal standard showed good quantification result for zeranol, zearalenone, as well as their isomers and metabolites, in beef.

• Proceedings of the PSK Conference
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• 2001.04a
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• pp.225.1-225.1
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• 2001

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.8
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• pp.3091-3096
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• 2015

Worldwide, breast cancer is the most common malignant neoplasm and the second most common cause of cancer death in women. This malignancy is recognized to be estrogen-dependent and due to this feature, hormone replacement therapy is regarded as potentially dangerous in breast cancer survivors who seek relief of their menopausal symptoms. Whereas hot flashes are detected in nearly half of postmenopausal women with a relatively high frequency and severity, botanic sources of estrogens have been proposed as an alternative treatment. Nevertheless, estrogenic properties of these compounds suggest possibility of stimulating cancer recurrence or worsening prognosis in survivors. As well, effects in improving vasomotor climacteric changes is controversial. Many studies have considered the subject, some focusing on efficacy of phytoestrogens for control of menopausal symptoms, and others discussing effects of these compounds on breast cancer outcome in terms of survival or recurrence. The present article is a concise review of the effects of consumption of phytoestrogens on menopausal symptoms, namely hot flashes, and breast cancer recurrence and mortality in survivors of the disease. Overall, the major part of the current existing literature is in favor of positive effects of phytoestrogens on breast cancer prognosis, but the efficacy on menopausal symptoms is probably minimal at the best.

• Journal of Embryo Transfer
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• v.27 no.4
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• pp.211-221
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• 2012

The process of embryo implantation requires physical contact and physiological communication between the conceptus trophectoderm and the maternal uterine endometrium. During the peri-implantation period in pigs, the conceptus undergoes significant morphological changes and secretes estrogens, the signal for maternal recognition of pregnancy. Estrogens secreted from the conceptus act on uterine epithelia to redirect $PGF_2{\alpha}$, luteolysin, secretion from the uterine vasculature to the uterine lumen to prevent luteolysis as well as to induce expression of endometrial genes that support implantation and conceptus development. In addition, conceptuses secrete cytokines, interferons, growth factors, and proteases, and in response to these signals, the uterine endometrium produces hormones, protease inhibitors, growth factors, transport proteins, adhesion molecules, lipid molecules, and calcium regulatory molecules. Coordinated interactions of these factors derived from the conceptus and the uterus play important roles in the process of implantation in pigs. To better understand mechanism of implantation process in pigs, this review provides information on signaling molecules at the conceptus-uterine interface during early pregnancy, including recently reported data reported.

• Applied Chemistry for Engineering
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• v.27 no.2
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• pp.217-220
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• 2016

Phytoestrogens are one of quasi-estrogens which are not generated within the endocrine system, but consumed by intaking phytoestrogenic plants. Phytoestrogens, also called as "dietary estrogens", are various botanic chemical compound groups naturally occurring nonsteroidal plant compounds of spontaneous generation. Due to their structural similarities to estrogone, they may provide desirable health benefits for reducing the menopausal symptoms. In this paper, various phytoestrogens were extracted from sophora root, pomegranate and kudzu by ultrasonic extraction process. In this study, the amount of extracted phytoestrogens at various ultrasonic power strengths and extraction times were compared, which could be used as basic data in the study of biology and chemistry related to natural products.

• Osteoporosis and Sarcopenia
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• v.2 no.3
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• pp.140-155
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• 2016

Sex steroids influence the maintenance and growth of muscles. Decline in androgens, estrogens and progesterone by aging leads to the loss of muscular function and mass, sarcopenia. These steroid hormones can interact with different signaling pathways through their receptors. To date, sex steroid hormone receptors and their exact roles are not completely defined in skeletal and smooth muscles. Although numerous studies focused on the effects of sex steroid hormones on different types of cells, still many unexplained molecular mechanisms in both skeletal and smooth muscle cells remain to be investigated. In this paper, many different molecular mechanisms that are activated or inhibited by sex steroids and those that influence the growth, proliferation, and differentiation of skeletal and smooth muscle cells are reviewed. Also, the similarities of cellular and molecular pathways of androgens, estrogens and progesterone in both skeletal and smooth muscle cells are highlighted. The reviewed signaling pathways and participating molecules can be targeted in the future development of novel therapeutics.