Displaying publications 1 - 20 of 27 in total

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  1. Expression of oestrogen-α receptor in papillary thyroid carcinoma and its association with metastasis
    Ab Halim SA, Lee SK, Mustangin M, Mohd Saleh MF, Shah SA, Md Isa N
    Malays J Pathol, 2020 Dec;42(3):415-422.
    PMID: 33361723
    INTRODUCTION: Papillary thyroid carcinoma (PTC) is the ninth most common malignancy among women. Although the disease prognosis is good, less favourable outcomes are predicted in those with higher disease stages and nodal metastasis. Oestrogen- α (ER-α) expression has been associated with aggressive presentation and greater disease progression and has been proposed as a predictor for lymph node metastases. The objective of this study was to evaluate the association between ER expression and clinicopathological features i.e. lymph node metastasis, tumour size, extrathyroidal extension, histological variants of PTC , age groups , ethnic and gender.

    METHODS: We studied ER-α expression in 84 cases of PTC obtained within an eight-year period (2011-2018) by immunohistochemical technique (IHC). Associations between ER-α expression and clinicopathological features were evaluated using Fisher's exact test. The statistical significance was set at p < 0.05.

    RESULTS: ER-α was expressed in 13.1% of all the PTC cases examined (n=11/84). There were no associations observed between ER-α expression and lymph node metastasis (p=1.000), tumour size (p=0.970), extrathyroidal extension (p=0.677), variants of PTC (p=1.000), age groups (p=0.188), gender (p=0.725) or race (p=0.920).

    CONCLUSION: There was no evidence in this study to support the application of ER-α as prediction marker for lymph node metastasis or disease aggressiveness in PTC. Given that the scope of this study was limited to the protein expression of ER- α, we also propose the inclusion of molecular analysis of ESR1 gene expression, as well as inclusion of detailed clinical and radiological findings in future research investigating the role of ER-α in prognostication of PTC.

    Matched MeSH terms: Estrogen Receptor alpha/biosynthesis*
  2. Fulltext Determining the endocrine disruption potential of industrial chemicals using an integrative approach: Public databases, in vitro exposure, and modeling receptor interactions
    Alofe O, Kisanga E, Inayat-Hussain SH, Fukumura M, Garcia-Milian R, Perera L, et al.
    Environ Int, 2019 10;131:104969.
    PMID: 31310931 DOI: 10.1016/j.envint.2019.104969
    Environmental and occupational exposure to industrial chemicals has been linked to toxic and carcinogenic effects in animal models and human studies. However, current toxicology testing does not thoroughly explore the endocrine disrupting effects of industrial chemicals, which may have low dose effects not predicted when determining the limit of toxicity. The objective of this study was to evaluate the endocrine disrupting potential of a broad range of chemicals used in the petrochemical sector. Therefore, 139 chemicals were classified for reproductive toxicity based on the United Nations Globally Harmonized System for hazard classification. These chemicals were evaluated in PubMed for reported endocrine disrupting activity, and their endocrine disrupting potential was estimated by identifying chemicals with active nuclear receptor endpoints publicly available databases. Evaluation of ToxCast data suggested that these chemicals preferentially alter the activity of the estrogen receptor (ER). Four chemicals were prioritized for in vitro testing using the ER-positive, immortalized human uterine Ishikawa cell line and a range of concentrations below the reported limit of toxicity in humans. We found that 2,6-di-tert-butyl-p-cresol (BHT) and diethanolamine (DEA) repressed the basal expression of estrogen-responsive genes PGR, NPPC, and GREB1 in Ishikawa cells, while tetrachloroethylene (PCE) and 2,2'-methyliminodiethanol (MDEA) induced the expression of these genes. Furthermore, low-dose combinations of PCE and MDEA produced additive effects. All four chemicals interfered with estradiol-mediated induction of PGR, NPPC, and GREB1. Molecular docking demonstrated that these chemicals could bind to the ligand binding site of ERα, suggesting the potential for direct stimulatory or inhibitory effects. We found that these chemicals altered rates of proliferation and regulated the expression of cell proliferation associated genes. These findings demonstrate previously unappreciated endocrine disrupting effects and underscore the importance of testing the endocrine disrupting potential of chemicals in the future to better understand their potential to impact public health.
    Matched MeSH terms: Estrogen Receptor alpha/metabolism; Estrogen Receptor alpha/chemistry
  3. Epigenetic oncogenesis, biomarkers and emerging chemotherapeutics for breast cancer
    Ayipo YO, Ajiboye AT, Osunniran WA, Jimoh AA, Mordi MN
    Biochim Biophys Acta Gene Regul Mech, 2022 10;1865(7):194873.
    PMID: 36064110 DOI: 10.1016/j.bbagrm.2022.194873
    Breast cancer remains one of the leading causes of cancer-related deaths globally and the most prominent among females, yet with limited effective therapeutic options. Most of the current medications are challenged by various factors including low efficacy, incessant resistance, immune evasion and frequent recurrence of the disease. Further understanding of the prognosis and identification of plausible therapeutic channels thus requires multimodal approaches. In this review, epigenetics studies of several pathways to BC oncogenesis via the inducement of oncogenic changes on relevant markers have been overviewed. Similarly, the counter-epigenetic mechanisms to reverse such changes as effective therapeutic strategies were surveyed. The epigenetic oncogenesis occurs through several pathways, notably, DNMT-mediated hypermethylation of DNA, dysregulated expression for ERα, HER2/ERBB and PR, histone modification, overexpression of transcription factors including the CDK9-cyclin T1 complex and suppression of tumour suppressor genes. Scientifically, the regulatory reversal of the mechanisms constitutes effective epigenetic approaches for mitigating BC initiation, progression and metastasis. These were exhibited at various experimental levels by classical chemotherapeutic agents including some repurposable drugs, endocrine inhibitors, monoclonal antibodies and miRNAs, natural products, metal complexes and nanoparticles. Dozens of the potential candidates are currently in clinical trials while others are still at preclinical experimental stages showing promising anti-BC efficacy. The review presents a model for a wider understanding of epigenetic oncogenic pathways to BC and reveals plausible channels for reversing the unpleasant changes through epigenetic modifications. It advances the science of therapeutic designs for ameliorating the global burden of BC upon further translational studies.
    Matched MeSH terms: Estrogen Receptor alpha/metabolism
  4. Fulltext Breast cancer risk variants at 6q25 display different phenotype associations and regulate ESR1, RMND1 and CCDC170
    Dunning AM, Michailidou K, Kuchenbaecker KB, Thompson D, French JD, Beesley J, et al.
    Nat Genet, 2016 Apr;48(4):374-86.
    PMID: 26928228 DOI: 10.1038/ng.3521
    We analyzed 3,872 common genetic variants across the ESR1 locus (encoding estrogen receptor α) in 118,816 subjects from three international consortia. We found evidence for at least five independent causal variants, each associated with different phenotype sets, including estrogen receptor (ER(+) or ER(-)) and human ERBB2 (HER2(+) or HER2(-)) tumor subtypes, mammographic density and tumor grade. The best candidate causal variants for ER(-) tumors lie in four separate enhancer elements, and their risk alleles reduce expression of ESR1, RMND1 and CCDC170, whereas the risk alleles of the strongest candidates for the remaining independent causal variant disrupt a silencer element and putatively increase ESR1 and RMND1 expression.
    Matched MeSH terms: Estrogen Receptor alpha/genetics*; Estrogen Receptor alpha/metabolism
  5. Fulltext Estrogen Receptors in Nonfunctioning Pituitary Neuroendocrine Tumors: Review on Expression and Gonadotroph Functions
    Haydar Ali Tajuddin A, Kamaruddin N, Sukor N, Azizan EA, Omar AM
    J Endocr Soc, 2020 Dec 01;4(12):bvaa157.
    PMID: 33241169 DOI: 10.1210/jendso/bvaa157
    Estrogen (17β-estradiol or E2) is a crucial regulator of the synthesis and secretion of pituitary reproductive hormones luteinizing hormone, follicle-stimulating hormone, and prolactin. In this review, we summarize the role of estrogen receptors in nonfunctioning pituitary neuroendocrine tumors (NF-Pitnets), focusing on immunoexpression and gonadotroph cell proliferation and apoptosis. Gonadotroph tumors are the most common subtype of NF-Pitnets. Two major estrogen receptor (ER) isoforms expressed in the pituitary are estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ). Overall, estrogen actions are mostly exerted through the ERα isoform on the pituitary. The G protein-coupled estrogen receptor (GPER) located at the plasma membrane may contribute to nongenomic effects of estrogen. Nuclear immunoreactivity for ERα and ERβ was highest among gonadotroph and null cell tumors. Silent corticotroph tumors are the least immunoreactive for both receptors. A significantly elevated ERα expression was observed in macroadenomas compared with microadenomas. ERα and ERβ may act in opposite directions to regulate the Slug-E-cadherin pathway and to affect invasiveness of NF-Pitnets. In the cellular pathway, ERs regulate estrogen-induced proliferation and differentiation and impact several signaling pathways including the MAPK and PI3K/Akt pathway. Estrogen was the first-discovered inducer of pituitary tumor transforming gene 1 that was abundantly expressed in NF-Pitnets. ERα can be a potential biomarker for predicting tumor size and invasiveness as well as therapeutic target for NF-Pitnets. Selective estrogen receptor modulators or antiestrogen may represent as an alternative choice for the treatment of NF-Pitnets.
    Matched MeSH terms: Estrogen Receptor alpha
  6. Oestrogenic activity of mimosine on MCF-7 breast cancer cell line through the ERα-mediated pathway
    Huq AM, Wai LK, Rullah K, Mohd Aluwi MFF, Stanslas J, Jamal JA
    Chem Biol Drug Des, 2019 03;93(3):222-231.
    PMID: 30251480 DOI: 10.1111/cbdd.13404
    Hormone replacement therapy has been a conventional treatment for postmenopausal symptoms in women. However, it has potential risks of breast and endometrial cancers. The aim of this study was to evaluate the oestrogenicity of a plant-based compound, mimosine, in MCF-7 cells by in silico model. Cell viability and proliferation, ERα-SRC1 coactivator activity and expression of specific ERα-dependent marker TFF1 and PGR genes were evaluated. Binding modes of 17β-oestradiol and mimosine at the ERα ligand binding domain were compared using docking and molecular dynamics simulation experiments followed by binding interaction free energy calculation with molecular mechanics/Poisson-Boltzmann surface area. Mimosine showed increased cellular viability (64,450 cells/ml) at 0.1 μM with significant cell proliferation (120.5%) compared to 17β-oestradiol (135.2%). ER antagonist tamoxifen significantly reduced proliferative activity mediated by mimosine (49.9%). Mimosine at 1 μM showed the highest ERα binding activity through increased SRC1 recruitment at 186.9%. It expressed TFF1 (11.1-fold at 0.1 μM) and PGR (13.9-fold at 0.01 μM) genes. ERα-mimosine binding energy was -49.9 kJ/mol, and it interacted with Thr347, Gly521 and His524 of ERα-LBD. The results suggested that mimosine has oestrogenic activity.
    Matched MeSH terms: Estrogen Receptor alpha/metabolism*; Estrogen Receptor alpha/chemistry
  7. Fulltext Design, synthesis and biological evaluation of 3-(2-aminooxazol-5-yl)-2H-chromen-2-one derivatives
    Kakkar S, Kumar S, Lim SM, Ramasamy K, Mani V, Shah SAA, et al.
    Chem Cent J, 2018 Dec 04;12(1):130.
    PMID: 30515643 DOI: 10.1186/s13065-018-0499-x
    BACKGROUND: In view of wide range of biological activities of oxazole, a new series of oxazole analogues was synthesized and its chemical structures were confirmed by spectral data (Proton/Carbon-NMR, IR, MS etc.). The synthesized oxazole derivatives were screened for their antimicrobial and antiproliferative activities.

    RESULTS AND DISCUSSION: The antimicrobial activity was performed against selected fungal and bacterial strains using tube dilution method. The antiproliferative potential was evaluated against human colorectal carcinoma (HCT116) and oestrogen- positive human breast carcinoma (MCF7) cancer cell lines using Sulforhodamine B assay and, results were compared to standard drugs, 5-fluorouracil and tamoxifen, respectively.

    CONCLUSION: The performed antimicrobial activity indicated that compounds 3, 5, 6, 8 and 14 showed promising activity against selected microbial species. Antiproliferative screening found compound 14 to be the most potent compound against HCT116 (IC50 = 71.8 µM), whereas Compound 6 was the most potent against MCF7 (IC50 = 74.1 µM). Further, the molecular docking study has been carried to find out the interaction between active oxazole compounds with CDK8 (HCT116) and ER-α (MCF7) proteins indicated that compound 14 and 6 showed good dock score with better potency within the ATP binding pocket and may be used as a lead for rational drug designing of the anticancer molecule.

    Matched MeSH terms: Estrogen Receptor alpha
  8. Sexual maturation modulates expression of nuclear receptor types in laser-captured single cells of the cichlid (Oreochromis niloticus) pituitary
    Kitahashi T, Ogawa S, Soga T, Sakuma Y, Parhar I
    Endocrinology, 2007 Dec;148(12):5822-30.
    PMID: 17823257
    The role of steroid/thyroid hormones in the regulation of endocrine cells at the level of the pituitary has remained unclear. Therefore, using single-cell quantitative real-time PCR, we examined absolute amounts of transcripts for nuclear receptors [estrogen receptors (ERs) alpha, beta, and gamma; androgen receptors (ARs) a and b; glucocorticoid receptors (GRs) 1, 2a, and 2b; and thyroid hormone receptors (TRs) alpha1, alpha2, and beta] in pituitary cells of immature (IM) and mature (M) male tilapia, Oreochromis niloticus. In the two reproductive stages, ACTH cells expressed only ERbeta, whereas all other pituitary cell types expressed ERalpha + beta, and a subpopulation coexpressed ARa, ARb, GR1, GR2b, and TRbeta but lacked ERgamma, GR2a, TRalpha1, and TRalpha2. IM males had high percentages of LH cells (IM 46.0% vs. M 10.0%), GH cells (IM 23.3% vs. M 7.9%), and prolactin cells (IM 68.8% vs. M 6.0%) with ERbeta, and TSH cells (IM 19.2% vs. M 0.0%) and MSH cells (IM 25.6% vs. M 0.0%) with ERalpha + TRbeta. A high percentage of FSH cells in IM males expressed ERbeta (IM 46.9% vs. M 18.8%), and FSH cells in M males showed significantly high GR1 transcripts (IM 76.0 +/- 5.0 vs. M 195.0 +/- 10.7 copies per cell; P < 0.05), suggesting that FSH cells are regulated differently in the two reproductive stages. Coexpression of ERalpha + beta in high percentages of cells of the GH family (GH, IM 43.8% vs. M 14.3%; prolactin, IM 8.3% vs. M 59.7%; somatolactin, IM 22.2% vs. M 42.2%) suggests that the expression of both ERs is important for functionality. Thus, differential coexpression of genes for nuclear receptors in subpopulations of pituitary cell types suggests multiple steroid/thyroid hormone regulatory pathways at the level of the pituitary during the two reproductive stages.
    Matched MeSH terms: Estrogen Receptor alpha/genetics
  9. Fulltext Breast Cancer Polygenic Risk Score and Contralateral Breast Cancer Risk
    Kramer I, Hooning MJ, Mavaddat N, Hauptmann M, Keeman R, Steyerberg EW, et al.
    Am J Hum Genet, 2020 11 05;107(5):837-848.
    PMID: 33022221 DOI: 10.1016/j.ajhg.2020.09.001
    Previous research has shown that polygenic risk scores (PRSs) can be used to stratify women according to their risk of developing primary invasive breast cancer. This study aimed to evaluate the association between a recently validated PRS of 313 germline variants (PRS313) and contralateral breast cancer (CBC) risk. We included 56,068 women of European ancestry diagnosed with first invasive breast cancer from 1990 onward with follow-up from the Breast Cancer Association Consortium. Metachronous CBC risk (N = 1,027) according to the distribution of PRS313 was quantified using Cox regression analyses. We assessed PRS313 interaction with age at first diagnosis, family history, morphology, ER status, PR status, and HER2 status, and (neo)adjuvant therapy. In studies of Asian women, with limited follow-up, CBC risk associated with PRS313 was assessed using logistic regression for 340 women with CBC compared with 12,133 women with unilateral breast cancer. Higher PRS313 was associated with increased CBC risk: hazard ratio per standard deviation (SD) = 1.25 (95%CI = 1.18-1.33) for Europeans, and an OR per SD = 1.15 (95%CI = 1.02-1.29) for Asians. The absolute lifetime risks of CBC, accounting for death as competing risk, were 12.4% for European women at the 10th percentile and 20.5% at the 90th percentile of PRS313. We found no evidence of confounding by or interaction with individual characteristics, characteristics of the primary tumor, or treatment. The C-index for the PRS313 alone was 0.563 (95%CI = 0.547-0.586). In conclusion, PRS313 is an independent factor associated with CBC risk and can be incorporated into CBC risk prediction models to help improve stratification and optimize surveillance and treatment strategies.
    Matched MeSH terms: Estrogen Receptor alpha/genetics; Estrogen Receptor alpha/metabolism
  10. Phenotyping of lymphocytes expressing regulatory and effector markers in infiltrating ductal carcinoma of the breast
    Leong PP, Mohammad R, Ibrahim N, Ithnin H, Abdullah M, Davis WC, et al.
    Immunol Lett, 2006 Feb 15;102(2):229-36.
    PMID: 16246429
    Dysfunction of the host immune system in cancer patients can be due to a number of reasons including suppression of tumour associated antigen reactive lymphocytes by regulatory T (Treg) cells. In this study, we used flow cytometry to determine the phenotype and relative abundance of the tumour infiltrating lymphocytes (TILs) from 47 enzymatically dissociated tumour specimens from patients with infiltrating ductal carcinoma (IDC) of the breast. The expression of both effector and regulatory markers on the TILs were determined by using a panel of monoclonal antibodies. Analysis revealed CD8(+) T cells (23.4+/-2.1%) were predominant in TILs, followed by CD4(+) T cells (12.6+/-1.7%) and CD56(+) natural killer cells (6.4+/-0.7%). The CD4(+)/CD8(+) ratio was 0.8+/-0.9%. Of the CD8(+) cells, there was a higher number (68.4+/-3.5%) that expressed the effector phenotype, namely, CD8(+)CD28(+) and about 46% of this subset expressed the activation marker, CD25. Thus, a lower number of infiltrating CD8(+) T cells (31.6+/-2.8%) expressed the marker for the suppressor phenotype, CD8(+)CD28(-). Of the CD4(+) T cells, 59.6+/-3.9% expressed the marker for the regulatory phenotype, CD4(+)CD25(+). About 43.6+/-3.8% CD4(+)CD25(+) subset co-expressed both the CD152 and FOXP3, the Treg-associated molecules. A positive correlation was found between the presence of CD4(+)CD25(+) subset and age (> or =50 years old) (r=0.51; p=0.045). However, no significant correlation between tumour stage and CD4(+)CD25(+) T cells was found. In addition, we also found that the CD4(+)CD25(-) subset correlated with the expression of the nuclear oestrogen receptor (ER)-alpha in the tumour cells (r=0.45; p=0.040). In conclusion, we detected the presence of cells expressing the markers for Tregs (CD4(+)CD25(+)) and suppressor (CD8(+)CD28(-)) in the tumour microenvironment. This is the first report of the relative abundance of Treg co-expressing CD152 and FOXP3 in breast carcinoma.
    Matched MeSH terms: Estrogen Receptor alpha/analysis
  11. Oestrogen actions contribute to female gender-specific risks in the development of lung carcinoma
    Liau CS, Mogan P, Thomas W
    J Steroid Biochem Mol Biol, 2021 04;208:105786.
    PMID: 33189851 DOI: 10.1016/j.jsbmb.2020.105786
    Lung cancer is increasing in incidence particularly among women, associated with a global change in smoking habits. Steroid hormones, particularly oestrogen exert an influence on tumour progression in tissues where their target receptor is expressed. Oestrogen receptor, particularly ERβ is highly expressed in the lung and becomes more highly expressed in lung carcinogenesis. Genes involved in the process of lung carcinoma progression and signalling cascades linked to invasion and angiogenesis are modulated by oestrogen receptors. This review intends to collate recently published evidence identifying a role for oestrogen in the initiation and progression of lung carcinoma and how these two processes are differentially affected by circulating oestrogens both in women and in men. Circulating oestrogens may be a significant risk factor in women's susceptibility to lung carcinoma and also provide an additional approach for more targeted therapy.
    Matched MeSH terms: Estrogen Receptor alpha/blood*
  12. Does cartilage ERα overexpression correlate with osteoarthritic chondrosenescence? Indications from Labisia pumila OA mitigation
    Madzuki IN, Lau SF, Mohamad Shalan NAA, Mohd Ishak NI, Mohamed S
    J Biosci, 2019 Sep;44(4).
    PMID: 31502578
    Chondrosenescence (chondrocyte senescence) and subchondral bone deterioration in osteoarthritic rats were analyzed after treatment with the estrogenic herb Labisia pumila (LP) or diclofenac. Osteoarthritis (OA) was induced in bilaterally ovariectomized (OVX) rats by injecting mono-iodoacetate into the right knee joints. Rats were grouped (n = 8) into nontreated OVX+OA control, OVX+OA + diclofenac (5 mg/kg) (positive control), OVX+OA + LP leaf extract (150 and 300 mg/kg) and healthy sham control. After 8 weeks' treatment, their conditions were evaluated via serum biomarkers, knee joint histology, bone histomorphometry, protein and mRNA expressions. The LP significantly reduced cartilage erosion, femur bone surface alteration, bone loss and porosity and increased trabecular bone thickness better than diclofenac and the non-treated OA. The cartilage catabolic markers' (matrix metalloproteinase (MMP)-13, RUNX2, COL10a, ERa, CASP3 and HIF-2 alpha) mRNA expressions were down-regulated and serum bone formation marker, PINP, was increased by LP in a dose-dependent manner. The LP (containing myricetin and gallic acid) showed protection against chondrosenescence, chondrocyte death, hypoxia-induced cartilage catabolism and subchondral bone deterioration. The bone and cartilage protective effects were by suppressing proteases (collagen break-down), bone resorption and upregulating subchondral bone restoration. The cartilage ER alpha over-expression showed a strong positive correlation with MMP-13, COL10 alpha1, histological, micro-computed tomography evidence for cartilage degradation and chondrosenescence.
    Matched MeSH terms: Estrogen Receptor alpha/genetics*
  13. α-Mangostin and its derivatives against estrogen receptor alpha
    Mardianingrum R, Yusuf M, Hariono M, Mohd Gazzali A, Muchtaridi M
    J Biomol Struct Dyn, 2020 Nov 06.
    PMID: 33155528 DOI: 10.1080/07391102.2020.1841031
    Estrogen receptor alpha (ERα) acts as the transcription factor and the main therapeutic target against breast cancer. One of the compounds that has been shown to act as an ERα is α-mangostin. However, it still has weaknesses due to its low solubility and low potent activity. In this study, α-mangostin was modified by substituting -OH group at C6 using benzoyl derivatives through a step by step in silico study, namely pharmacokinetic prediction (https://preadmet.bmdrc.kr/adme/), pharmacophore modeling (LigandScout 4.1), molecular docking simulation (AutoDock 4.2), molecular dynamics simulation (AMBER 16) and a binding free energy analysis using MM-PBSA method. From the computational studies, three compounds which are derived from α-mangostin (AMB-1 (-9.84 kcal/mol), AMB-2 (-6.80 kcal/mol) and AMB-10 (-12.42 kcal/mol)) have lower binding free energy than α-mangostin (-1.77 kcal/mol), as evidenced by the binding free energy calculation using the MM-PBSA method. They can then be predicted to have potent activities as ERα antagonists.Communicated by Ramaswamy H. Sarma.
    Matched MeSH terms: Estrogen Receptor alpha
  14. A concise review of testosterone and bone health
    Mohamad NV, Soelaiman IN, Chin KY
    Clin Interv Aging, 2016;11:1317-1324.
    PMID: 27703340
    Osteoporosis is a condition causing significant morbidity and mortality in the elderly population worldwide. Age-related testosterone deficiency is the most important factor of bone loss in elderly men. Androgen can influence bone health by binding to androgen receptors directly or to estrogen receptors (ERs) indirectly via aromatization to estrogen. This review summarized the direct and indirect effects of androgens on bone derived from in vitro, in vivo, and human studies. Cellular studies showed that androgen stimulated the proliferation of preosteoblasts and differentiation of osteoblasts. The converted estrogen suppressed osteoclast formation and resorption activity by blocking the receptor activator of nuclear factor k-B ligand pathway. In animal studies, activation of androgen and ERα, but not ERβ, was shown to be important in acquisition and maintenance of bone mass. Human epidemiological studies demonstrated a significant relationship between estrogen and testosterone in bone mineral density and fracture risk, but the relative significance between the two remained debatable. Human experimental studies showed that estrogen was needed in suppressing bone resorption, but both androgen and estrogen were indispensable for bone formation. As a conclusion, maintaining optimal level of androgen is essential in preventing osteoporosis and its complications in elderly men.
    Matched MeSH terms: Estrogen Receptor alpha/physiology
  15. Fulltext Tualang Honey Protects against BPA-Induced Morphological Abnormalities and Disruption of ERα, ERβ, and C3 mRNA and Protein Expressions in the Uterus of Rats
    Mohamad Zaid SS, Kassim NM, Othman S
    Evid Based Complement Alternat Med, 2015;2015:202874.
    PMID: 26788107 DOI: 10.1155/2015/202874
    Bisphenol A (BPA) is an endocrine disrupting chemical (EDC) that can disrupt the normal functions of the reproductive system. The objective of the study is to investigate the potential protective effects of Tualang honey against BPA-induced uterine toxicity in pubertal rats. The rats were administered with BPA by oral gavage over a period of six weeks. Uterine toxicity in BPA-exposed rats was determined by the degree of the morphological abnormalities, increased lipid peroxidation, and dysregulated expression and distribution of ERα, ERβ, and C3 as compared to the control rats. Concurrent treatment of rats with BPA and Tualang honey significantly improved the uterine morphological abnormalities, reduced lipid peroxidation, and normalized ERα, ERβ, and C3 expressions and distribution. There were no abnormal changes observed in rats treated with Tualang honey alone, comparable with the control rats. In conclusion, Tualang honey has potential roles in protecting the uterus from BPA-induced toxicity, possibly accounted for by its phytochemical properties.
    Matched MeSH terms: Estrogen Receptor alpha
  16. Fulltext Potential activity of fevicordin-A from Phaleria macrocarpa (Scheff) Boerl. seeds as estrogen receptor antagonist based on cytotoxicity and molecular modelling studies
    Muchtaridi M, Yusuf M, Diantini A, Choi SB, Al-Najjar BO, Manurung JV, et al.
    Int J Mol Sci, 2014 Apr 25;15(5):7225-49.
    PMID: 24776765 DOI: 10.3390/ijms15057225
    Fevicordin-A (FevA) isolated from Phaleria macrocarpa (Scheff) Boerl. seeds was evaluated for its potential anticancer activity by in vitro and in silico approaches. Cytotoxicity studies indicated that FevA was selective against cell lines of human breast adenocarcinoma (MCF-7) with an IC50 value of 6.4 µM. At 11.2 µM, FevA resulted in 76.8% cell death of T-47D human breast cancer cell lines. Critical pharmacophore features amongst human Estrogen Receptor-α (hERα) antagonists were conserved in FevA with regard to a hypothesis that they could make notable contributions to its pharmacological activity. The binding stability as well as the dynamic behavior of FevA towards the hERα receptor in agonist and antagonist binding sites were probed using molecular dynamics (MD) simulation approach. Analysis of MD simulation suggested that the tail of FevA was accountable for the repulsion of the C-terminal of Helix-11 (H11) in both agonist and antagonist receptor forms. The flexibility of loop-534 indicated the ability to disrupt the hydrogen bond zipper network between H3 and H11 in hERα. In addition, MM/GBSA calculation from the molecular dynamic simulations also revealed a stronger binding affinity of FevA in antagonistic action as compared to that of agonistic action. Collectively, both the experimental and computational results indicated that FevA has potential as a candidate for an anticancer agent, which is worth promoting for further preclinical evaluation.
    Matched MeSH terms: Estrogen Receptor alpha/metabolism; Estrogen Receptor alpha/chemistry
  17. Estrogenic phytochemical from Labisia pumila (Myrsinaceae) with selectivity towards estrogen receptor alpha and beta subtypes
    Muhamad M, Choo CY, Hasuda T, Hitotsuyanagi Y
    Fitoterapia, 2019 Sep;137:104256.
    PMID: 31295513 DOI: 10.1016/j.fitote.2019.104256
    Labisia pumila var. alata (Myrsinaceae) or "Kacip fatimah" is a famous Malay traditional herb used for the maintenance of women's health. The extracts of L.pumila displayed estrogenic activity in rats. Nonetheless, the estrogenic bioactives were not identified. The aim of the study is to identify estrogenic compounds contributing to the established estrogenic activity. Bioactivity-guided-isolation method guided the isolation of pure bioactives. The hexane extract was subjected to a series of silica gel flash and open column chromatography with increasing amount of ethyl acetate in hexane or methanol in chloroform. Each fraction or pure compounds were evaluated on it's estrogen receptor (ER) binding activity with the fluorescence polarization competitive ERα and ERβ binding assay kit. Cytotoxic assay using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay method was used to establish the cytotoxic activity of the compounds. Four alkyl resorcinols and a dimeric 1,4-benzoquinone, namely belamcandol B (1), 5-pentadec-10'-(Z)-enyl resorcinol (2), 1,3-dihydroxy-5-pentadecylbenzene (3), 5-(heptadec-12'-(Z)-enyl) resorcinol (4) and demethylbelamcandaquinone B (5) were identified with selective binding affinities towards either ERα or ERβ exhibiting selectivity ratio from 0.15-11.9. Alkyl resorcinols (2)-(4) exhibited cytotoxic activity towards HL60 cells with IC50 values from 19.5-22.0 μM. Structural differences between compounds influence the binding affinities to ER subtypes. Further study is needed to establish the agonist or antagonist effect of these compounds on various tissues and to identify if these compounds exert cytotoxic activity through the ERs. When consuming L.pumila as a complementary medicine, careful consideration regarding it's estrogenic compound content should be given due consideration.
    Matched MeSH terms: Estrogen Receptor alpha/drug effects*
  18. Fulltext Tocotrienols and breast cancer: the evidence to date
    Nesaretnam K, Meganathan P, Veerasenan SD, Selvaduray KR
    Genes Nutr, 2012 Jan;7(1):3-9.
    PMID: 21516480 DOI: 10.1007/s12263-011-0224-z
    Breast cancer is the second most frequent cancer affecting women worldwide after lung cancer. The toxicity factor associated with synthetic drugs has turned the attention toward natural compounds as the primary focus of interest as anticancer agents. Vitamin E derivatives consisting of the well-established tocopherols and their analogs namely tocotrienols have been extensively studied due to their remarkable biological properties. While tocopherols have failed to offer protection, tocotrienols, in particular, α-, δ-, and γ-tocotrienols alone and in combination have demonstrated anticancer properties. The discovery of the antiangiogenic, antiproliferative, and apoptotic effects of tocotrienols, as well as their role as an inducer of immunological functions, not only reveals a new horizon as a potent antitumor agent but also reinforces the notion that tocotrienols are indeed more than antioxidants. On the basis of a transcriptomic platform, we have recently demonstrated a novel mechanism for tocotrienol activity that involves estrogen receptor (ER) signaling. In silico simulations and in vitro binding analyses indicate a high affinity of specific forms of tocotrienols for ERβ, but not for ERα. Moreover, we have demonstrated that specific tocotrienols increase ERβ translocation into the nucleus which, in turn, activates the expression of estrogen-responsive genes (MIC-1, EGR-1 and Cathepsin D) in breast cancer cells only expressing ERβ cells (MDA-MB-231) and in cells expressing both ER isoforms (MCF-7). The binding of specific tocotrienol forms to ERβ is associated with the alteration of cell morphology, caspase-3 activation, DNA fragmentation, and apoptosis. Furthermore, a recently concluded clinical trial seems to suggest that tocotrienols in combination with tamoxifen may have the potential to extend breast cancer-specific survival.
    Matched MeSH terms: Estrogen Receptor alpha
  19. Development and Validation of Decision Forest Model for Estrogen Receptor Binding Prediction of Chemicals Using Large Data Sets
    Ng HW, Doughty SW, Luo H, Ye H, Ge W, Tong W, et al.
    Chem Res Toxicol, 2015 Dec 21;28(12):2343-51.
    PMID: 26524122 DOI: 10.1021/acs.chemrestox.5b00358
    Some chemicals in the environment possess the potential to interact with the endocrine system in the human body. Multiple receptors are involved in the endocrine system; estrogen receptor α (ERα) plays very important roles in endocrine activity and is the most studied receptor. Understanding and predicting estrogenic activity of chemicals facilitates the evaluation of their endocrine activity. Hence, we have developed a decision forest classification model to predict chemical binding to ERα using a large training data set of 3308 chemicals obtained from the U.S. Food and Drug Administration's Estrogenic Activity Database. We tested the model using cross validations and external data sets of 1641 chemicals obtained from the U.S. Environmental Protection Agency's ToxCast project. The model showed good performance in both internal (92% accuracy) and external validations (∼ 70-89% relative balanced accuracies), where the latter involved the validations of the model across different ER pathway-related assays in ToxCast. The important features that contribute to the prediction ability of the model were identified through informative descriptor analysis and were related to current knowledge of ER binding. Prediction confidence analysis revealed that the model had both high prediction confidence and accuracy for most predicted chemicals. The results demonstrated that the model constructed based on the large training data set is more accurate and robust for predicting ER binding of chemicals than the published models that have been developed using much smaller data sets. The model could be useful for the evaluation of ERα-mediated endocrine activity potential of environmental chemicals.
    Matched MeSH terms: Estrogen Receptor alpha
  20. Fulltext Fine-mapping identifies two additional breast cancer susceptibility loci at 9q31.2
    Orr N, Dudbridge F, Dryden N, Maguire S, Novo D, Perrakis E, et al.
    Hum Mol Genet, 2015 May 15;24(10):2966-84.
    PMID: 25652398 DOI: 10.1093/hmg/ddv035
    We recently identified a novel susceptibility variant, rs865686, for estrogen-receptor positive breast cancer at 9q31.2. Here, we report a fine-mapping analysis of the 9q31.2 susceptibility locus using 43 160 cases and 42 600 controls of European ancestry ascertained from 52 studies and a further 5795 cases and 6624 controls of Asian ancestry from nine studies. Single nucleotide polymorphism (SNP) rs676256 was most strongly associated with risk in Europeans (odds ratios [OR] = 0.90 [0.88-0.92]; P-value = 1.58 × 10(-25)). This SNP is one of a cluster of highly correlated variants, including rs865686, that spans ∼14.5 kb. We identified two additional independent association signals demarcated by SNPs rs10816625 (OR = 1.12 [1.08-1.17]; P-value = 7.89 × 10(-09)) and rs13294895 (OR = 1.09 [1.06-1.12]; P-value = 2.97 × 10(-11)). SNP rs10816625, but not rs13294895, was also associated with risk of breast cancer in Asian individuals (OR = 1.12 [1.06-1.18]; P-value = 2.77 × 10(-05)). Functional genomic annotation using data derived from breast cancer cell-line models indicates that these SNPs localise to putative enhancer elements that bind known drivers of hormone-dependent breast cancer, including ER-α, FOXA1 and GATA-3. In vitro analyses indicate that rs10816625 and rs13294895 have allele-specific effects on enhancer activity and suggest chromatin interactions with the KLF4 gene locus. These results demonstrate the power of dense genotyping in large studies to identify independent susceptibility variants. Analysis of associations using subjects with different ancestry, combined with bioinformatic and genomic characterisation, can provide strong evidence for the likely causative alleles and their functional basis.
    Matched MeSH terms: Estrogen Receptor alpha/genetics
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