• Title/Summary/Keyword: Estrogen receptor (ER)

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15d-PGJ2 Induces Apoptosis of MCF-7 and MDA-MB-231 Cells via Increased Intracellular Calcium and Activation of Caspases, Independent of ERα and ERβ

  • Muhammad, Siti Nur Hasyila;Mokhtar, Noor Fatmawati;Yaacob, Nik Soriani
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.7
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    • pp.3223-3228
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    • 2016
  • Reports indicate that 15-deoxy-delta-12,14-prostaglandin-J2 (15d-PGJ2) has anticancer activities, but its mechanisms of action have yet to be fully elucidated. We therefore investigated the effects of 15d-PGJ2 on the human breast cancer cell lines, MCF-7 (estrogen receptor $ER{\alpha}+/ER{\beta}+$) and MDA-MB-231 ($ER{\alpha}-/ER{\beta}+$). Cellular proliferation and cytotoxicity were determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays while apoptosis was determined by fluorescence microscopy and flow cytometry using annexin V-propidium iodide (PI) staining. ER expression was determined by Western blotting. Intracellular calcium was stained with Fluo-4 AM while intracellular caspase activities were detected with Caspase-$FLICA(R)$ and measured by flow cytometry. We showed that 15d-PGJ2 caused a significant increase in apoptosis in MCF-7 and MDA-MB-231 cells. $ER{\alpha}$ protein expression was reduced in treated MCF-7 cells but pre-incubation with the $ER{\alpha}$ inhibitor' ICI 182 780' did not affect the percentage of apoptotic cells. The expression of $ER{\beta}$ was unchanged in both cell lines. In addition, 15d-PGJ2 increased intracellular calcium ($Ca^{2+}$) staining and caspase 8, 9 and 3/7 activities. We therefore conclude that 15d-PGJ2 induces caspase-dependent apoptosis that is associated with an influx of intracellular $Ca^{2+}$ with no involvement of ER signaling.

Estrogen Induces CK2α Activation via Generation of Reactive Oxygen Species

  • Jeong, Soo-Yeon;Im, Suhn-Young
    • Biomedical Science Letters
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    • v.25 no.1
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    • pp.23-31
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    • 2019
  • The protein kinase $CK2{\alpha}$ (formerly Casein Kinase II) is implicated in tumorigenesis and transformation. However, the mechanisms of $CK2{\alpha}$ activation in breast cancer have yet to be elucidated. This study investigated the mechanisms of $CK2{\alpha}$ activation in estrogen signaling. Estrogen increased reactive oxygen species (ROS) production, $CK2{\alpha}$ activity, and protein expression in estrogen receptor positive ($ER^+$) MCF-7 human breast cancer cells, which were inhibited by the antioxidant N-acetyl-L-cysteine. $H_2O_2$ enhanced $CK2{\alpha}$ activity and protein expression. Human epidermal growth factor (EGF) increased ROS production, $CK2{\alpha}$ activity and protein expression in EGF receptor 2 (HER2)-overexpressing MCF-7 (MCF-7 HER2) cells, but not in MCF-7 cells. Estrogen induced the phosphorylation of p38 mitogen-activated protein kinase (MAPK). The p38 inhibitor, SB202190, blocked estrogen-induced increases in ROS production, $CK2{\alpha}$ activity and $CK2{\alpha}$ protein expression. The data suggest that ROS/p38 MAPK is the key inducer of $CK2{\alpha}$ activation in response to estrogen or EGF.

Tectoridin, a Poor Ligand of Estrogen Receptor α, Exerts Its Estrogenic Effects via an ERK-Dependent Pathway

  • Kang, Kyungsu;Lee, Saet Byoul;Jung, Sang Hoon;Cha, Kwang Hyun;Park, Woo Dong;Sohn, Young Chang;Nho, Chu Won
    • 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.

Expressional Correlation of Human Epidermal Growth Factor Receptor 2, Estrogen/Progesterone Receptor and Protein 53 in Breast Cancer

  • Panahi, Marzieh;Saki, Najmaldin;Ashourzadeh, Sara;Rahim, Fakher
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.6
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    • pp.3699-3703
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    • 2013
  • Background: This study aimed to show the localization of estrogen / progesterone receptors, human epidermal growth factor receptor 2 (Her-2) and protein 53 (p53) by immunohistochemistry in a series of consecutive breast cancer patients. Materials and Methods: The study covered invasive breast cancers from 299 patients presenting at the Oncogenetic Clinic and Pathology Centers of Ahwaz Jondishapour University of Medical Sciences Hospital in Iran during the time period from 2009 to 2011. The Scarff-Bloom Richardson scoring method was used. Results: Of the 299, 27% (80/299) were <40, 33% (100/299) were 41-50, and the remaining 40% (119/299) were>50 years old. The highest incidence of breast cancer in this study population was in the group of more than 50 year age, and the most common histological type of breast cancer was the invasive ductal carcinoma, which accounted for 68% (203/299) of the cases. Out of possible total of 207, 6% (13/207), 41% (85/207), and 53% (109/207) were scored as grade I, II, III, respectively. Conclusion: Our findings demonstrated a lack of association between labeling for the markers studied and tumor size and age of the patients. We confirmed an association between ER labeling and nuclear grade of breast cancer. The conflicting results obtained compared with the literature be because of differences in the immunohistochemical techniques applied in the various studies and to the scoring systems used.

Estrogen activity of Silkworm (Bombyx mori) Pupa water extract and its fractions

  • Ryu, Jae-Sung;Jo, Gyeong-Jong;Jin, Jung-Woo;Yang, Hyo-Jung;Park, Yong-Il;Na, Ye-Seul;Nam, Kyung-Su;Keum, Kyung-Soo;Choo, Young-Kug
    • Advances in Traditional Medicine
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    • v.8 no.3
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    • pp.228-235
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    • 2008
  • This study was conducted to evaluate the estrogen activity of silkworm (Bombyx mori) pupa extracts and their fractions. Powdered samples of freeze-dried silkworm pupa were extracted at room temperature (RT), $40^{\circ}C$, $60^{\circ}C$, $80^{\circ}C$, and $100^{\circ}C$ in water (D.W), chloroform, ethyl acetate, and methanol for 6h and then filtered (0.45 um). The extracts were then freeze-dried. The estrogenic activity of these extracts was then investigated by competition binding assays using estrogen receptor ${\alpha}\;(ER{\alpha})$ and $ER{\beta}$, and by evaluating their effects on the proliferation of the human breast cancer cell line, MCF-7. Among the extracts evaluated, water extracts prepared at RT showed the highest binding affinity to $ER{\alpha}$ ($IC_{50}$, 1.76 ug/ml) and $ER{\beta}$ ($IC_{50}$, 0.07 ug/ml). In addition, MCF-7 cells that were treated with 62.5 ug/ml of the RT extract showed the greatest increase in proliferation (2-fold; 1291.79%) when compared to control cells (659.82%). Next, the water extract that was prepared at RT (sample 1) was dissolved in D.W. and further fractionated using a Dowex 50W - 8X ($H^+$) column. The flow-through and wash were then pooled together and freeze-dried (sample 2). The bound materials were then eluted with 20 mM NaCl, after which they were applied to a Dowex 1X2 - 200 ($Cl^-$) column and washed with D.W. to remove the sodium ions. The eluants were then freeze-dried (sample 3). Of these fractions, sample 2 showed the highest binding affinity to ER{\alpha} ($IC_{50}$, 1.44 ug/ml) and $ER{\beta}$ ($IC_{50}$, 1.18 ug/ml). In addition, MCF-7 cells that were treated with sample 2 (15.6 ug/ml) showed the largest increase in growth (1159.39%) when compared to control cells (525.26%). Taken together, these results suggest that the fraction of the RT water extract of silkworm pupa referred to as sample 2 may be useful as a phytoestrogen.

Study on Estrogenic Activities of Phthalate Esters Using E-screen Assay and Competitive Binding Assay (E-screen Assay 및 상경적 결합반응을 이용한 Phthalate Esters의 내분비계 장애 작용 연구)

  • 한순영;한상국;문현주;김형식;이동하;김소희;김태성;박귀례
    • Toxicological Research
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    • v.16 no.2
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    • pp.141-146
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    • 2000
  • Phthalate esters are used extensively as a plasticizer in the manufacture of plastic products such as PVC bags and medical devices. Recently, phthalate esters have been shown to induce endocrine system mediated responses. However. only a Jew studies have been conducted for estrogenic activity of phthalate esters. In this study estrogenic activities of seven phthalate esters. butyl benzyl phthalate (BBP), di(2-ethylhexyl) phthalate (DEHP), di-n-butylphthalate (DBP), diethylphthalate (DEP), di-n-pentylphthalate (DPP), di-n-propylphthalate (DPrP) and dicyclohexylphthalate (DCHP), were examined in vitro using E-screen assay and competitive binding assay. From the E-screen assay, BBP. DEHP. DBP and DEP showed weak estrogenic activity at the concentration of 5 $\mu\textrm{M}$. The relative proliferative effect (RPE) and the relative proliferative potency (RPP) were 50~70% and 0.01%. respectively, when compared with 500 pM of 17$\beta$-estradiol (E2). In competitive binding assay with the rat uterine estrogen receptor (ER), BBP and DEP showed weak binding potency [(l/$10^4$~1/$10^5$ of E2] while DEHP and DBP scarcely bound to ER. These results suggest that some phthalate esters have weak estrogenic activities in vitro.

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In Silico Docking Studies of Selected Flavonoids - Natural Healing Agents against Breast Cancer

  • Suganya, Jeyabaskar;Radha, Mahendran;Naorem, Devi Leimarembi;Nishandhini, Marimuthu
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.19
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    • pp.8155-8159
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    • 2014
  • Background: Breast cancer is the serious health concern in India causing the highest mortality rate in females, which occurs due to uncontrolled cell division and can be metastasize to other parts of the human body. Interactions with estrogen receptor (ER) alpha are mainly responsible for the malignant tumors with regulation of the transcription of various genes as a transcription factor. Most of the drugs currently used for the breast cancer treatment produce various side effects and hence we focused on natural compounds which do not exhibit any toxic effect against normal human cells. Materials and Methods: Structure of human ER was retrieved from the Protein Data Bank and the structures of flavonoid compounds have been collected from PubChem database. Molecular docking and drug likeness studies were performed for those natural compounds to evaluate and analyze the anti-breast cancer activity. Results: Finally two compounds satisfying the Lipinski's rule of five were reported. The two compounds also exhibited highest binding affinity with human ER greater than 10.5 Kcal/mol. Conclusions: The results of this study can be implemented in the drug designing pipeline.

Effects of Panax ginseng, zearalenol, and estradiol on sperm function

  • Gray, Sandra L.;Lackey, Brett R.;Boone, William R.
    • Journal of Ginseng Research
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    • v.40 no.3
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    • pp.251-259
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    • 2016
  • Background: Estrogen signaling pathways are modulated by exogenous factors. Panax ginseng exerts multiple activities in biological systems and is classified as an adaptogen. Zearalenol is a potent mycoestrogen that may be present in herbs and crops arising from contamination or endophytic association. The goal of this study was to investigate the impact of P. ginseng, zearalenol and estradiol in tests on spermatozoal function. Methods: The affinity of these compounds for estrogen receptor (ER)-alpha and beta ($ER{\alpha}$ and $ER{\beta}$)-was assessed in receptor binding assays. Functional tests on boar spermatozoa motility, movement and kinematic parameters were conducted using a computer-assisted sperm analyzer. Tests for capacitation, acrosome reaction (AR), and chromatin decondensation in spermatozoa were performed using microscopic analysis. Results: Zearalenol-but not estradiol ($E_2$)- or ginseng-treated spermatozoa-decreased the percentage of overall, progressive, and rapid motile cells. Zearalenol also decreased spontaneous AR and increased chromatin decondensation. Ginseng decreased chromatin decondensation in response to calcium ionophore and decreased AR in response to progesterone ($P_4$) and ionophore. Conclusion: Zearalenol has adverse effects on sperm motility and function by targeting multiple signaling cascades, including $P_4$, $E_2$, and calcium pathways. Ginseng protects against chromatin damage and thus may be beneficial to reproductive fitness.

Reduction of Estradiol Receptor in Rat Atretic Follicle Induced by Dihydrotestoterone Enanthate (DHTE) (DHTE로 유발된 흰쥐 폐쇄난포의 에스트라디올 수용체의 감소)

  • 유용달;이창주;이준영
    • Journal of Embryo Transfer
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    • v.5 no.2
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    • pp.28-37
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    • 1990
  • Dihydrotestoterone (DHT)은 난소내 폐쇄를 유발한다고 보고 되었으나, 반대로 폐쇄를 억제한다는 상반된 주장이 있어왔다. 본 연구는 난소내 폐쇄되는 기작을 밝히는 연구의 일환으로 흰쥐의 DHT를 처리하여 난포가 폐쇄되는지 여부와 폐쇄된다면 스테로이드 수용체, 특히 에스트라디올 수용체에 어떠한 영향을 주는지를 조사하고자 하였다. 미성숙 흰쥐의 뇌하수체를 절제(HPX)하고, 35IU의 PMSG 처리후 Dihydrotestoterone enathate (DHTE)를 lmg-5mg/kg 체중 농도로 처리하여 난포의 폐쇄여부를 조직학적으로 검경하였다. PMSG,PMSG-DHTE 공히 강소를 형성한 난포의 acid phosphatase 활성도를 증가시켰고, 또한 난포의 폐쇄를 유발하였다. 흰쥐의 난소내 estrogen receptor (ER)의 수는 과립세포에서도 세포질내 ER은 핵내로 이용되는 것을 확인하였다. 또한 DHTE는 난소내 ER의 농도를 감소시켰다. 이 결과로 보아 난포내 DHTE는 ER의 농도를 감소시켜 폐쇄를 유발하는 요인으로 작용할 것이라는 결론을 얻었다.

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The Estrogen Receptor Negative-Progesterone Receptor Positive Breast Carcinoma is a Biological Entity and not a Technical Artifact

  • Ng, Char Hong;Pathy, Nirmala Bhoo;Taib, Nur Aishah;Mun, Kein Seong;Rhodes, Anthony;Yip, Cheng Har
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.4
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    • pp.1111-1113
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    • 2012
  • The ER-/PR+ breast tumor may be the result of a false ER negative result. The aim of this study was to investigate whether there is a difference in patient and tumor characteristics of the ER-/PR+ phenotype in an Asian setting. A total of 2629 breast cancer patients were categorized on the basis of their age, ethnicity, tumor hormonal receptor phenotype, grade and histological type. There were 1230 (46.8%) ER+/PR+, 306 (11.6%) ER+/PR-, 122 (4.6%) ER-/PR+ and 972 (37%) ER-/PR-. ER-/PR+ tumors were 2.5 times more likely to be younger than 50 years at diagnosis (OR: 2.52; 95% CI: 1.72-3.67). Compared to ER+/PR+ tumors, the ER-/PR+ phenotype was twice more likely to be associated with grade 3 tumors (OR:2.02; 95%CI: 1.00-4.10). In contrast, compared to ER-/PR- tumors, the ER-/PR+ phenotype was 90% less likely to be associated with a grade 3 tumor (OR: 0.12; 95%CI:0.05-0.26), and more likely to have invasive lobular than invasive ductal histology (OR: 3.66; 95%CI: 1.47-9.11). These results show that the ER-/PR+ phenotype occurs in a younger age group and is associated with intermediate histopathological characteristics compared to ER+/PR+ and ER-/PR- tumors. This may imply that it is a distinct entity and not a technical artifact.