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Lu D, Yang L, Li Q, Gao X, Wang F, Zhang G. Egonol gentiobioside and egonol gentiotrioside from Styrax perkinsiae promote the biosynthesis of estrogen by aromatase. Eur J Pharmacol 2012; 691:275-82. [DOI: 10.1016/j.ejphar.2012.07.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Revised: 07/02/2012] [Accepted: 07/02/2012] [Indexed: 10/28/2022]
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Orsatti FL, Nahas EA, Orsatti CL, de Oliveira EP, Nahas-Neto J, da Mota GR, Burini RC. Muscle Mass Gain After Resistance Training Is Inversely Correlated With Trunk Adiposity Gain in Postmenopausal Women. J Strength Cond Res 2012; 26:2130-9. [DOI: 10.1519/jsc.0b013e318239f837] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Rice S, Patel B, Bano G, Ugwumadu A, Whitehead SA. Aromatase expression in abdominal omental/visceral and subcutaneous fat depots: a comparison of pregnant and obese women. Fertil Steril 2012; 97:1460-6.e1. [DOI: 10.1016/j.fertnstert.2012.03.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Revised: 02/15/2012] [Accepted: 03/06/2012] [Indexed: 12/01/2022]
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Yang H, Sukocheva OA, Hussey DJ, Watson DI. Estrogen, male dominance and esophageal adenocarcinoma: is there a link? World J Gastroenterol 2012; 18:393-400. [PMID: 22346245 PMCID: PMC3270506 DOI: 10.3748/wjg.v18.i5.393] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2011] [Revised: 08/11/2011] [Accepted: 08/15/2011] [Indexed: 02/06/2023] Open
Abstract
Esophageal adenocarcinoma is a cancer with poor prognosis, and its incidence has risen sharply over recent decades. Obesity is a major risk factor for developing this cancer and there is a clear male gender bias in the incidence that cannot be fully explained by known risk factors. It is possible that a difference in the expression of estrogen, or its signaling axes, may contribute to this gender bias. We undertook a comprehensive literature search and analyzed the available data regarding estrogen and estrogen receptor expression, and the possible sex-specific links with esophageal adenocarcinoma development. Potentially relevant associations between visceral vs subcutaneous fat deposition and estrogen expression, and the effect of crosstalk between estrogen and leptin signaling were identified. We also found limited studies suggesting a role for estrogen receptor β expression in esophageal adenocarcinoma development. The current literature supports speculation on an etiological role for estrogen in the male gender bias in esophageal adenocarcinoma, but further studies are required.
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Gao R, Zhao L, Liu X, Rowan BG, Wabitsch M, Edwards DP, Nishi Y, Yanase T, Yu Q, Dong Y. Methylseleninic acid is a novel suppressor of aromatase expression. J Endocrinol 2012; 212:199-205. [PMID: 22128327 DOI: 10.1530/joe-11-0363] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Elevated circulating estrogen levels, as a result of increased peripheral aromatization of androgens by aromatase, have been indicated to underlie the association between obesity and a higher risk of breast cancer in postmenopausal women. Although aromatase inhibitors have been used as a first-line therapy for estrogen receptor-positive breast cancer in postmenopausal women, their potential as breast cancer chemopreventive agents has been limited due to toxicities and high costs. It is therefore imperative to develop new aromatase-inhibiting/suppressing agents with lower toxicities and lower costs for breast cancer chemoprevention, especially in obese postmenopausal women. The expression of the aromatase gene, CYP19, is controlled in a tissue-specific manner by the alternate use of different promoters. In obese postmenopausal women, increased peripheral aromatase is primarily attributed to the activity of the glucocorticoid-stimulated promoter, PI.4, and the cAMP-stimulated promoter, PII. In the present study, we show that methylseleninic acid (MSA), a second-generation selenium compound, can effectively suppress aromatase activation by dexamethasone, a synthetic glucocorticoid, and forskolin, a specific activator of adenylate cyclase. Unlike the action of aromatase inhibitors, MSA suppression of aromatase activation is not mediated via direct inhibition of aromatase enzymatic activity. Rather, it is attributable to a marked downregulation of promoters PI.4- and PII-specific aromatase mRNA expression, and thereby a reduction of aromatase protein. Considering the low-cost and low-toxicity nature of MSA, our findings provide a strong rationale for the further development of MSA as a breast cancer chemopreventive agent for obese postmenopausal women.
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Affiliation(s)
- Ruijuan Gao
- Department of Structural and Cellular Biology, Tulane University School of Medicine, Tulane Cancer Center, New Orleans, Louisiana 70112, USA
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The effect of glucocorticoids on sex steroid synthesis in cultured Taenia crassiceps Wake Forest University (WFU) cysticerci. J Helminthol 2011; 86:465-9. [PMID: 22152276 DOI: 10.1017/s0022149x11000708] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We have shown previously that cultured Taenia crassiceps Wake Forest University (WFU) and Taenia solium cysticerci, as well as the adult worms, synthesize sex steroid hormones from [3H]steroid precursors and that androgens and oestrogens influence the in vitro development of the parasites. Glucocorticoids (GCs) are used to control the inflammation caused by T. solium cysticerci in the brain. These steroids stimulate oestrogen synthesis in several tissues. Since there is no information on the effect of GC on the endocrine function of cysticerci, we investigated the effect of natural and synthetic GCs on the synthesis of oestrogens in cultured T. crassiceps WFU cysticerci. The cysticerci were obtained from the peritoneal cavity of infected female BALB/c mice; the cysts were washed extensively and pre-cultured in Dulbecco's Modified Eagle's Medium (DMEM) plus antibiotics for 5 days. The parasites were further cultured with different doses of corticosterone, dexamethasone or the vehicle for 5 days. [3H]Dehydroepiandrosterone (3H-DHEA) was added to the media and the cysticerci were further incubated for 6 or 24 h. Media were then removed and the steroids ether-extracted. Aliquots of the media were seeded on silica gel plates and developed in solvent systems. Parasites incubated in the presence of 3H-DHEA synthesized [3H]androstenediol, [3H]testosterone and [3H]17β-oestradiol ([3H]17β-E2). The addition of 100 nm or higher corticosterone doses to the media increased [3H]17β-E2 synthesis fourfold after 24 h. Dexamethasone also increased [3H]17β-E2 synthesis. The experiments presented here show for the first time that corticosterone and the synthetic GC dexamethasone modulate the synthesis of oestrogens by cysticerci.
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Macciò A, Madeddu C. Obesity, inflammation, and postmenopausal breast cancer: therapeutic implications. ScientificWorldJournal 2011; 11:2020-36. [PMID: 22125453 PMCID: PMC3217612 DOI: 10.1100/2011/806787] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Accepted: 09/29/2011] [Indexed: 12/25/2022] Open
Abstract
Breast cancer is the female malignant neoplasia with the highest incidence in the industrialized world. Although early diagnosis has contributed to therapeutic success, breast cancer remains a major health issue. In the last few year the hormone therapy for estrogen-dependent breast cancer has evolved achieving significant clinical results; at the same time, it has enabled us to better define the role of estrogens in the etiopathogenesis of this tumour. Weight increase and obesity have been identified as the most important risk and prognostic factors for breast cancer in postmenopausal women. Several hypotheses have been proposed to explain the association of obesity with postmenopausal breast cancer. Specific obesity-associated factors, including leptin, insulin and inflammatory mediators, seem to influence breast cancer growth and prognosis independently of estrogens and at least in part by interacting with estrogen signalling at a cellular level. Therefore, a careful assessment of the nutritional status and body composition is paramount for a proper therapeutic approach for postmenopausal breast carcinoma. The use of antidiabetic and anti-inflammatory drugs associated with conventional hormone therapies and dietary/physical interventions could offer a new therapeutic approach for breast carcinoma that develops in the context of adiposity.
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Affiliation(s)
- Antonio Macciò
- Department of Obstetrics and Gynecology, Sirai Hospital, 09013 Carbonia, Italy.
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Stimulation of serotonergic 5-HT2A receptor signaling increases placental aromatase (CYP19) activity and expression in BeWo and JEG-3 human choriocarcinoma cells. Placenta 2011; 32:651-656. [PMID: 21703684 DOI: 10.1016/j.placenta.2011.06.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2011] [Revised: 06/03/2011] [Accepted: 06/06/2011] [Indexed: 01/23/2023]
Abstract
It is known that serotonin can influence the production and function of sex hormones, such as estrogens. Estrogens are critical for maintenance of pregnancy and regulate placental and fetal development. The key enzyme controlling estrogens synthesis during pregnancy is placental aromatase (CYP19). To better understand the regulation of placental aromatase, this study determined whether serotonin is involved in the regulation of this enzyme. BeWo and JEG-3 choriocarcinoma cells were used as models of the human placental trophoblast to evaluate the effects of serotonin and selective 5-HT(2A) receptor agonists on CYP19 activity and expression. Serotonin and selective 5-HT(2A) receptor agonists as well as PKC activation increased aromatase activity and expression in BeWo and JEG-3 cells. Dexamethasone, which regulates aromatase expression via JAK/STAT activation in certain tissues, had no effect. Increased CYP19 gene transcription by 5-HT(2A) receptor and PKC stimulation was mediated by activation of the placental I.1 aromatase promoter. This study shows that the serotonergic system modulates placental aromatase expression, which would result in altered estrogens biosynthesis in trophoblast cells. Future detailed studies of serotonin-estrogen interactions in placenta are crucial for an improved understanding of the endo-, para- and autocrine role of serotonin during pregnancy and fetal development.
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Khan SI, Zhao J, Khan IA, Walker LA, Dasmahapatra AK. Potential utility of natural products as regulators of breast cancer-associated aromatase promoters. Reprod Biol Endocrinol 2011; 9:91. [PMID: 21693041 PMCID: PMC3142499 DOI: 10.1186/1477-7827-9-91] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Accepted: 06/21/2011] [Indexed: 12/21/2022] Open
Abstract
Aromatase, the key enzyme in estrogen biosynthesis, converts androstenedione to estrone and testosterone to estradiol. The enzyme is expressed in various tissues such as ovary, placenta, bone, brain, skin, and adipose tissue. Aromatase enzyme is encoded by a single gene CYP 19A1 and its expression is controlled by tissue-specific promoters. Aromatase mRNA is primarily transcribed from promoter I.4 in normal breast tissue and physiological levels of aromatase are found in breast adipose stromal fibroblasts. Under the conditions of breast cancer, as a result of the activation of a distinct set of aromatase promoters (I.3, II, and I.7) aromatase expression is enhanced leading to local overproduction of estrogen that promotes breast cancer. Aromatase is considered as a potential target for endocrine treatment of breast cancer but due to nonspecific reduction of aromatase activity in other tissues, aromatase inhibitors (AIs) are associated with undesirable side effects such as bone loss, and abnormal lipid metabolism. Inhibition of aromatase expression by inactivating breast tumor-specific aromatase promoters can selectively block estrogen production at the tumor site. Although several synthetic chemical compounds and nuclear receptor ligands are known to inhibit the activity of the tumor-specific aromatase promoters, further development of more specific and efficacious drugs without adverse effects is still warranted. Plants are rich in chemopreventive agents that have a great potential to be used in chemotherapy for hormone dependent breast cancer which could serve as a source for natural AIs. In this brief review, we summarize the studies on phytochemicals such as biochanin A, genistein, quercetin, isoliquiritigenin, resveratrol, and grape seed extracts related to their effect on the activation of breast cancer-associated aromatase promoters and discuss their aromatase inhibitory potential to be used as safer chemotherapeutic agents for specific hormone-dependent breast cancer.
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Affiliation(s)
- Shabana I Khan
- National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, School of Pharmacy, University of Mississippi, University, MS 38677, USA
- Department of Pharmacognosy, University of Mississippi, University, MS 38677, USA
| | - Jianping Zhao
- National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, School of Pharmacy, University of Mississippi, University, MS 38677, USA
| | - Ikhlas A Khan
- National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, School of Pharmacy, University of Mississippi, University, MS 38677, USA
- Department of Pharmacognosy, University of Mississippi, University, MS 38677, USA
| | - Larry A Walker
- National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, School of Pharmacy, University of Mississippi, University, MS 38677, USA
- Department of Pharmacology, University of Mississippi, MS 38677, USA
- University of Mississippi Cancer Institute, University of Mississippi, University, MS 38677, USA
| | - Asok K Dasmahapatra
- National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, School of Pharmacy, University of Mississippi, University, MS 38677, USA
- Department of Pharmacology, University of Mississippi, MS 38677, USA
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Abstract
After the menopausal transition, the ovaries cease to make estrogens, yet the incidence of breast cancer increases and the majority of these tumors are estrogen receptor positive. So, where is the estrogen driving this tumor development coming from? Several extragonadal sites, such as bone, brain and adipose tissue, synthesize estrogens from circulating C19 steroids. The largest of these depots is the adipose tissue, and increased BMI is associated with increased breast cancer risk as well as increased circulating estrogen levels. The mechanisms linking obesity to breast cancer risk are not yet completely understood, although it is widely assumed that estrogens produced in the fat play a role. This article aims to provide a comprehensive overview of the regulation of aromatase expression in the breast adipose tissue in response to fat and tumor-derived factors, as well as new evidence suggesting that breast-specific inhibition of aromatase may be possible.
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Affiliation(s)
- Evan R Simpson
- a Prince Henry's Institute of Medical Research, and the Departments of Biochemistry and Physiology, Monash University, Clayton, Victoria 3168, Australia
- b
| | - Kristy A Brown
- a Prince Henry's Institute of Medical Research, and the Departments of Biochemistry and Physiology, Monash University, Clayton, Victoria 3168, Australia
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Aromatase Inhibitor Exemestane has Antiproliferative Effects on Human Mesothelioma Cells. J Thorac Oncol 2011; 6:583-91. [DOI: 10.1097/jto.0b013e31820cdd6f] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Dossus L, Rinaldi S, Becker S, Lukanova A, Tjonneland A, Olsen A, Stegger J, Overvad K, Chabbert-Buffet N, Jimenez-Corona A, Clavel-Chapelon F, Rohrmann S, Teucher B, Boeing H, Schütze M, Trichopoulou A, Benetou V, Lagiou P, Palli D, Berrino F, Panico S, Tumino R, Sacerdote C, Redondo ML, Travier N, Sanchez MJ, Altzibar JM, Chirlaque MD, Ardanaz E, Bueno-de-Mesquita HB, van Duijnhoven FJB, Onland-Moret NC, Peeters PHM, Hallmans G, Lundin E, Khaw KT, Wareham N, Allen N, Key TJ, Slimani N, Hainaut P, Romaguera D, Norat T, Riboli E, Kaaks R. Obesity, inflammatory markers, and endometrial cancer risk: a prospective case-control study. Endocr Relat Cancer 2010; 17:1007-19. [PMID: 20843938 PMCID: PMC2966326 DOI: 10.1677/erc-10-0053] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Obesity, a major risk factor for endometrial cancer, is a low-grade inflammatory state characterized by elevated concentrations of cytokines and acute phase reactants. The current study had two aims: first to investigate the associations of C-reactive protein (CRP), interleukin 6 (IL6), and IL1 receptor antagonist (IL1Ra) with endometrial cancer risk and second to examine to which extent these markers can influence the association between obesity and endometrial cancer. We conducted a case-control study, nested within the European Prospective Investigation into Cancer and Nutrition, which comprised 305 incident cases of endometrial cancer and 574 matched controls. CRP, IL6, and IL1Ra were measured in prospectively collected blood specimens by immunoassays. Data were analyzed using conditional logistic regression. All statistical tests were two-sided, and P values <0.05 were considered statistically significant. We observed a significant increase in risk of endometrial cancer with elevated levels of CRP (odds ratio (OR) for top versus bottom quartile: 1.58, 95% confidence interval (CI): 1.03-2.41, P(trend)=0.02), IL6 (OR for top versus bottom quartile: 1.66, 95% CI: 1.08-2.54, P(trend)=0.008), and IL1Ra (OR for top versus bottom quartile: 1.82, 95% CI: 1.22-2.73, P(trend)=0.004). After adjustment for body mass index (BMI), the estimates were strongly reduced and became non-significant. The association between BMI and endometrial cancer was also substantially attenuated (∼10-20%) after adjustment for inflammatory markers, even when the effects of C-peptide or estrone had already been taken into account. We provided epidemiological evidence that chronic inflammation might mediate the association between obesity and endometrial cancer and that endometrial carcinogenesis could be promoted by an inflammatory milieu.
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Affiliation(s)
- Laure Dossus
- Division of Cancer EpidemiologyGerman Cancer Research Center (DKFZ)Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 280, 69120, HeidelbergGermany
| | - Sabina Rinaldi
- Section of Nutrition and MetabolismInternational Agency for Research on CancerLyon, 69372France
| | - Susen Becker
- Division of Cancer EpidemiologyGerman Cancer Research Center (DKFZ)Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 280, 69120, HeidelbergGermany
| | - Annekatrin Lukanova
- Division of Cancer EpidemiologyGerman Cancer Research Center (DKFZ)Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 280, 69120, HeidelbergGermany
- Department of Obstetrics and GynecologyNew York University School of MedicineNew York, New York, 10016USA
| | - Anne Tjonneland
- Institute of Cancer EpidemiologyDanish Cancer SocietyCopenhagen, 2100Denmark
| | - Anja Olsen
- Institute of Cancer EpidemiologyDanish Cancer SocietyCopenhagen, 2100Denmark
| | - Jakob Stegger
- Department of CardiologyAalborg Hospital, Aarhus University HospitalAalborg, 9100Denmark
| | - Kim Overvad
- Department of CardiologyAalborg Hospital, Aarhus University HospitalAalborg, 9100Denmark
- Department of EpidemiologySchool of Public Health, Aarhus UniversityAarhus, 8000Denmark
| | | | - Aida Jimenez-Corona
- Inserm, Center for Research in Epidemiology and Population Health, Paris South University, Gustave Roussy InstitutVillejuif, 94805France
- National Institute of Public HealthCuernavaca, Morelos, 62100Mexico
| | - Francoise Clavel-Chapelon
- Inserm, Center for Research in Epidemiology and Population Health, Paris South University, Gustave Roussy InstitutVillejuif, 94805France
| | - Sabine Rohrmann
- Division of Cancer EpidemiologyGerman Cancer Research Center (DKFZ)Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 280, 69120, HeidelbergGermany
| | - Birgit Teucher
- Division of Cancer EpidemiologyGerman Cancer Research Center (DKFZ)Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 280, 69120, HeidelbergGermany
| | - Heiner Boeing
- Department of EpidemiologyGerman Institute of Human Nutrition Potsdam-RehbrueckeNuthetal, 14558Germany
| | - Madlen Schütze
- Department of EpidemiologyGerman Institute of Human Nutrition Potsdam-RehbrueckeNuthetal, 14558Germany
| | - Antonia Trichopoulou
- WHO Collaborating Center for Food and Nutrition Policies, Department of Hygiene Epidemiology and Medical StatisticsUniversity of Athens Medical SchoolAthens, 11527Greece
- Hellenic Health FoundationAthens, 11527Greece
| | - Vassiliki Benetou
- WHO Collaborating Center for Food and Nutrition Policies, Department of Hygiene Epidemiology and Medical StatisticsUniversity of Athens Medical SchoolAthens, 11527Greece
| | - Pagona Lagiou
- WHO Collaborating Center for Food and Nutrition Policies, Department of Hygiene Epidemiology and Medical StatisticsUniversity of Athens Medical SchoolAthens, 11527Greece
| | - Domenico Palli
- Molecular and Nutritional Epidemiology UnitCancer Research and Prevention Institute (ISPO)Florence, 50139Italy
| | - Franco Berrino
- Epidemiology Unit, Department of Preventive and Predicitive MedicineFondazione IRCCS Istituto Nazionale TumoriMilan, 20139Italy
| | - Salvatore Panico
- Department of Clinical and Experimental MedicineFederico II UniversityNaples, 80138Italy
| | - Rosario Tumino
- Cancer Registry and Histopathology Unit‘Civile – M.P. Arezzo’ HospitalRagusa, 97100Italy
| | - Carlotta Sacerdote
- Center for Cancer Prevention (CPO Piedmont)Turin, 10123Italy
- Human Genetic Foundation (Hugef)Turin, 10126Italy
| | - Maria-Luisa Redondo
- Public Health and Participation Directorate, Health and Health Care Services Council, AsturiasOviedo, 33001Spain
| | - Noémie Travier
- Unit of Nutrition Environment and CancerCancer Epidemiology Research Programme, Catalan Institute of Oncology (ICO)Barcelona, 08907Spain
| | - Maria-Jose Sanchez
- Andalusian School of Public HealthGranada, 18011Spain
- CIBER Epidemiologia y Salud Publica (CIBERESP)Barcelona, 08003Spain
| | - Jone M Altzibar
- CIBER Epidemiologia y Salud Publica (CIBERESP)Barcelona, 08003Spain
- Department of Public Health of GuipuzkoaSan Sebastian, 20013Spain
| | - Maria-Dolores Chirlaque
- CIBER Epidemiologia y Salud Publica (CIBERESP)Barcelona, 08003Spain
- Department of EpidemiologyMurcia Regional Health AuthorityMurcia, 30008Spain
| | - Eva Ardanaz
- CIBER Epidemiologia y Salud Publica (CIBERESP)Barcelona, 08003Spain
- Public Health Institute of NavarraPamplona, 31003Spain
| | - H Bas Bueno-de-Mesquita
- National Institute for Public Health and the Environment (RIVM)Bilthoven, 3720 BAThe Netherlands
| | | | - N Charlotte Onland-Moret
- Julius Center for Health Sciences and Primary CareUniversity Medical CenterUtrecht, 3508 GAThe Netherlands
| | - Petra H M Peeters
- Julius Center for Health Sciences and Primary CareUniversity Medical CenterUtrecht, 3508 GAThe Netherlands
| | - Goran Hallmans
- Department of Public Health and Clinical Medicine, Nutritional ResearchUmea UniversityUmea, 90187Sweden
| | - Eva Lundin
- Department of Medical Biosciences, PathologyUmea UniversityUmea, 90187Sweden
| | - Kay-Tee Khaw
- Department of Public Health and Primary CareUniversity of CambridgeCambridge, CB1 8RNUK
| | | | - Naomi Allen
- Cancer Epidemiology Unit, Department of Clinical MedicineUniversity of Oxford NuffieldOxford, OX3 7XPUK
| | - Tim J Key
- Cancer Epidemiology Unit, Department of Clinical MedicineUniversity of Oxford NuffieldOxford, OX3 7XPUK
| | - Nadia Slimani
- Section of Nutrition and MetabolismInternational Agency for Research on CancerLyon, 69372France
| | - Pierre Hainaut
- Section of Mechanisms of CarcinogenesisInternational Agency for Research on CancerLyon, 69372France
| | - Dora Romaguera
- Department of Epidemiology and BiostatisticsSchool of Public Health, Imperial CollegeLondon, SW7UK
| | - Teresa Norat
- Department of Epidemiology and BiostatisticsSchool of Public Health, Imperial CollegeLondon, SW7UK
| | - Elio Riboli
- Department of Epidemiology and BiostatisticsSchool of Public Health, Imperial CollegeLondon, SW7UK
| | - Rudolf Kaaks
- Division of Cancer EpidemiologyGerman Cancer Research Center (DKFZ)Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 280, 69120, HeidelbergGermany
- (Correspondence should be addressed to R Kaaks; )
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Miki Y, Suzuki T, Abe K, Suzuki S, Niikawa H, Iida S, Hata S, Akahira JI, Mori K, Evans DB, Kondo T, Yamada-Okabe H, Sasano H. Intratumoral localization of aromatase and interaction between stromal and parenchymal cells in the non-small cell lung carcinoma microenvironment. Cancer Res 2010; 70:6659-69. [PMID: 20710045 DOI: 10.1158/0008-5472.can-09-4653] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Estrogens produced as a result of intratumoral aromatization has been recently shown to play important roles in proliferation of human non-small cell lung carcinomas (NSCLC), but the details have remained largely unknown. Therefore, in this study, we evaluated the possible roles of intratumoral aromatase in NSCLCs as follows: (a) evaluation of intratumoral localization of aromatase mRNA/protein in six lung adenocarcinoma cases using laser capture microdissection combined with quantitative reverse transcriptase-PCR and immunohistochemistry; (b) examination of the possible effects of isolated stromal cells from lung carcinoma tissues on aromatase mRNA transcript expression in lung carcinoma cell lines (A549 and LK87) through a coculture system; and (c) screening of cytokines derived from stromal LK001S and LK002S cells using cytokine antibody arrays and subsequent evaluation of effects of these cytokines on aromatase expression in A549 and LK87. Both aromatase mRNA and protein were mainly detected in intratumoral carcinoma cells but not in stromal cells. Aromatase expression of A549 and LK87 was upregulated in the presence of LK001S or LK002S cells. Several cytokines such as interleukin-6 (IL-6), oncostatin M, and tumor necrosis factor-alpha, all known as inducible factors of aromatase gene, were detected in conditioned media of LK001S and LK002S cells. Treatment of both oncostatin M and IL-6 induced aromatase gene expression in A549 an LK87, respectively. These results all indicated that intratumoral microenvironments, especially carcinoma-stromal cell interactions, play a pivotal role in the regulation of intratumoral estrogen synthesis through aromatase expression in human lung adenocarcinomas.
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Affiliation(s)
- Yasuhiro Miki
- Department of Pathology, Tohoku University Graduate School of Medicine, Sendai, Japan
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Zhang B, Shozu M, Okada M, Ishikawa H, Kasai T, Murakami K, Nomura K, Harada N, Inoue M. Insulin-like growth factor I enhances the expression of aromatase P450 by inhibiting autophagy. Endocrinology 2010; 151:4949-58. [PMID: 20668023 DOI: 10.1210/en.2010-0294] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Aromatase, a key enzyme of estrogen biosynthesis, is transcriptionally regulated by many growth factors. IGF-I enhances aromatase activity in a variety of cells, but the mechanism of action has not been determined. We herein report our finding of a novel mechanism of action for IGF-I. IGF-I enhanced the dexamethasone (DEX)-induced aromatase activity by 30% in serum-starved THP-1 cells. The increase was associated with a corresponding increase in the level of aromatase protein but not with any change in the mRNA level. Metabolic labeling experiments revealed that IGF-I inhibited the degradation of aromatase. We identified pepstatin A as the most effective inhibitor of aromatase degradation by in vitro assay. Using a nontoxic concentration of pepstatin A, we examined IGF-I's action on aromatase distribution in microsomes and lysosomes. In the presence of pepstatin A, DEX caused an increase in the amount of aromatase in both microsomes and lysosomes, and IGF-I attenuated the DEX-induced accumulation of aromatase in lysosomes and, conversely, enhanced its accumulation in the microsomes. The addition of serum abolished the IGF-I-induced changes. The transport from microsome to lysosome was fluorescently traced in cells using a recombinant aromatase. IGF-I selectively reduced the aromatase signal in the lysosomes. Finally, we observed that IGF-I enhanced the aromatase activity by 50% as early as 1 h after treatment; furthermore, rapamycin, an enhancer of autophagy, completely negated the effect of IGF-I on the enzyme. These results indicate that IGF-I enhances aromatase by the inhibition of autophagy.
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Affiliation(s)
- Bo Zhang
- Department of Obstetrics and Gynecology, Kanazawa University Graduate School of Medicine, Kanazawa 920-0934, Japan
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Knower KC, To SQ, Simpson ER, Clyne CD. Epigenetic mechanisms regulating CYP19 transcription in human breast adipose fibroblasts. Mol Cell Endocrinol 2010; 321:123-30. [PMID: 20211687 DOI: 10.1016/j.mce.2010.02.035] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2009] [Revised: 01/27/2010] [Accepted: 02/26/2010] [Indexed: 01/09/2023]
Abstract
Cytochrome aromatase p450, encoded by the gene CYP19, catalyzes the synthesis of estrogens from androgens. In post-menopausal women, adipose becomes the major site for estrogen production, where basal CYP19 transcription is driven by distal promoter I.4. In breast adipose fibroblasts (BAFs), CYP19 expression is elevated in the presence of tumour-derived factors through use of promoters I.3 and II. We show for the first time that DNA methylation contributes to CYP19 regulation in BAFs and breast cell lines. Promoter I.4 and I.3/II-derived mRNA were not dependent on the CpG methylation status within respective promoters. However, inhibition of DNA methylation with 5-aza-2'-deoxycytidine resulted in a significant approximately 40-fold induction in CYP19 mRNA expression in BAFs and breast cell lines. These studies uncover a new layer of complexity in the regulation of aromatase where CYP19 appears to be inhibited by DNA methylation and evokes the possibility that disruption to this epigenetic regulation may give rise to an increase in aromatase levels in the breast.
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Affiliation(s)
- Kevin C Knower
- Prince Henry's Institute of Medical Research, Clayton, Victoria, Australia.
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66
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Macciò A, Madeddu C, Mantovani G. Adipose tissue as target organ in the treatment of hormone-dependent breast cancer: new therapeutic perspectives. Obes Rev 2009; 10:660-70. [PMID: 19460113 DOI: 10.1111/j.1467-789x.2009.00592.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Breast cancer is the female malignant neoplasia with the highest incidence in the industrialized world. Despite many undeniable therapeutic successes obtained, breast cancer still remains, however, a major health issue. In the last few years, thanks to aromatase inhibitors, the hormone therapy for oestrogen-dependent breast cancer has evolved in terms of efficacy and tolerability; at the same time, it has enabled us to better define the role of oestrogens in the etiopathogenesis of this tumour. Weight increase and obesity have been identified as the most important risk and prognostic factors for breast cancer in postmenopausal women. Several hypotheses have been proposed to explain the association of obesity with postmenopausal breast cancer. A more recent hypothesis suggests that adipocytes and their autocrine (paracrine and endocrine actions) are at the centre of such an etiopathogenetic mechanism. A better understanding of the main mechanisms that link together menopause, body-weight increase and hormone-dependent breast cancer is paramount to enable the identification of key molecules involved in the development of breast carcinoma and suggest new therapeutic options. The present review will discuss important findings on the therapeutic aspects of adipose tissue and adipokines as a target for treatment of hormone-dependent breast cancer.
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Affiliation(s)
- A Macciò
- Department of Obstetrics and Gynecology, Sirai Hospital, Carbonia, Italy.
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Howgate DJ, Gamie Z, Panteliadis P, Bhalla A, Mantalaris A, Tsiridis E. The potential adverse effects of aromatase inhibitors on wound healing:in vitroandin vivoevidence. Expert Opin Drug Saf 2009; 8:523-35. [DOI: 10.1517/14740330903190674] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Santen RJ, Brodie H, Simpson ER, Siiteri PK, Brodie A. History of aromatase: saga of an important biological mediator and therapeutic target. Endocr Rev 2009; 30:343-75. [PMID: 19389994 DOI: 10.1210/er.2008-0016] [Citation(s) in RCA: 284] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Aromatase is the enzyme that catalyzes the conversion of androgens to estrogens. Initial studies of its enzymatic activity and function took place in an environment focused on estrogen as a component of the birth control pill. At an early stage, investigators recognized that inhibition of this enzyme could have major practical applications for treatment of hormone-dependent breast cancer, alterations of ovarian and endometrial function, and treatment of benign disorders such as gynecomastia. Two general approaches ultimately led to the development of potent and selective aromatase inhibitors. One targeted the enzyme using analogs of natural steroidal substrates to work out the relationships between structure and function. The other approach initially sought to block adrenal function as a treatment for breast cancer but led to the serendipitous finding that a nonsteroidal P450 steroidogenesis inhibitor, aminoglutethimide, served as a potent but nonselective aromatase inhibitor. Proof of the therapeutic concept of aromatase inhibition involved a variety of studies with aminoglutethimide and the selective steroidal inhibitor, formestane. The requirement for even more potent and selective inhibitors led to intensive molecular studies to identify the structure of aromatase, to development of high-sensitivity estrogen assays, and to "mega" clinical trials of the third-generation aromatase inhibitors, letrozole, anastrozole, and exemestane, which are now in clinical use in breast cancer. During these studies, unexpected findings led investigators to appreciate the important role of estrogens in males as well as in females and in multiple organs, particularly the bone and brain. These studies identified the important regulatory properties of aromatase acting in an autocrine, paracrine, intracrine, neurocrine, and juxtacrine fashion and the organ-specific enhancers and promoters controlling its transcription. The saga of these studies of aromatase and the ultimate utilization of inhibitors as highly effective treatments of breast cancer and for use in reproductive disorders serves as the basis for this first Endocrine Reviews history manuscript.
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Affiliation(s)
- R J Santen
- University of Virginia Health System, Division of Endocrinology, P.O. Box 801416, Charlottesville, Virginia 22908, USA.
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69
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Zhao H, Innes J, Brooks DC, Reierstad S, Yilmaz MB, Lin Z, Bulun SE. A novel promoter controls Cyp19a1 gene expression in mouse adipose tissue. Reprod Biol Endocrinol 2009; 7:37. [PMID: 19393092 PMCID: PMC2684739 DOI: 10.1186/1477-7827-7-37] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2009] [Accepted: 04/24/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Aromatase, the key enzyme in estrogen biosynthesis, is encoded by the Cyp19a1 gene. Thus far, 3 unique untranslated first exons associated with distinct promoters in the mouse Cyp19a1 gene have been described (brain, ovary, and testis-specific). It remains unknown whether aromatase is expressed in other mouse tissues via novel and tissue-specific promoters. METHODS Real-time PCR was used to examine the aromatase expression levels in various C57BL/6 mouse tissues. 5'-rapid amplification of cDNA ends (5'-RACE) was used to determine the transcriptional start sites of Cyp19a1 transcripts. Promoter activity was measured using serial deletion mutants of DNA fused to the luciferase reporter gene. Primary mouse adipose fibroblasts were isolated and cultured from 16-week-old mouse gonadal fat pads. RESULTS We systematically analyzed Cyp19a1 expression in a large number of mouse tissues, and demonstrated for the first time that aromatase was expressed in the male but not female gonadal fat pad. Subcutaneous and brown adipose tissue did not contain detectable Cyp19a1 mRNA. We used 5'-RACE to clone a novel gonadal fat-specific untranslated first exon, which is spliced onto a common junction 15 bp upstream of the translation start site. This adipose-specific first exon was mapped to approximately 75 kb upstream of the translation start site. Transfection of luciferase reporter gene plasmids containing the promoter region upstream of the adipose-specific first exon into murine 3T3-L1 adipose fibroblasts demonstrated significant basal promoter activity conferred primarily by the sequence located at -343/-1 bp. Dexamethasone significantly induced activity of this adipose-specific promoter region. Adipose-specific Cyp19a1 mRNA was expressed in primary mouse adipose fibroblasts and significantly induced by dexamethasone alone or serum plus dexamethasone. CONCLUSION Taken together, this research identified a novel, adipose-specific first exon of Cyp19a1 and its hormonally regulated promoter region in male murine gonadal fat. These results expand the known 5'-regulatory region of the murine Cyp19a1 gene to 75 kb upstream of the translation start site. Cyp19a1 expression in mouse adipose tissue may play an important role in reproductive biology and lipid metabolism.
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Affiliation(s)
- Hong Zhao
- Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
| | - Joy Innes
- Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
| | - David C Brooks
- Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
| | - Scott Reierstad
- Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
| | - Mehmet B Yilmaz
- Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
| | - Zhihong Lin
- Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
| | - Serdar E Bulun
- Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
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Yague JG, Garcia-Segura LM, Azcoitia I. Selective transcriptional regulation of aromatase gene by vitamin D, dexamethasone, and mifepristone in human glioma cells. Endocrine 2009; 35:252-61. [PMID: 19116788 DOI: 10.1007/s12020-008-9134-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2008] [Revised: 10/29/2008] [Accepted: 11/24/2008] [Indexed: 10/21/2022]
Abstract
The human aromatase gene (CYP19A1) is controlled by multiple promoters that give rise to different aromatase transcripts. Its regulation has been studied in cells from multiple origins, including placenta, bone, adipose tissue, and breast cancer. However, little is known about its regulation in cells from neural origin. We assessed whether vitamin D, dexamethasone, and the glucocorticoid receptor antagonist mifepristone regulate the aromatase gene in human glioma, neuroblastoma, and breast cancer cells. The results show that these compounds enhance the activity of different aromatase promoters in glioma cells, but not in neuroblastoma and breast cancer cells. Vitamin D increased the expression of I.3, I.7, and I.4 aromatase transcripts and induced de novo expression of the I.6 transcript; dexamethasone increased the expression of I.4, PII, and I.3 transcripts and mifepristone increased the expression of PII and I.3 aromatase transcripts. The cell specific regulation of CYP19A1 by vitamin D, dexamethasone, and mifepristone opens the possibility for cellular selective modulation of estrogen biosynthesis within the brain.
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Affiliation(s)
- Josue G Yague
- Instituto Cajal, CSIC, Avenida Doctor Arce 37, 28002 Madrid, Spain
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71
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Haidari K, Salehnia M, Rezazadeh Valojerdi M. The effect of leukemia inhibitory factor and coculture on the in vitro maturation and ultrastructure of vitrified and nonvitrified isolated mouse preantral follicles. Fertil Steril 2008; 90:2389-97. [DOI: 10.1016/j.fertnstert.2007.10.052] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2007] [Revised: 10/22/2007] [Accepted: 10/22/2007] [Indexed: 10/22/2022]
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72
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73
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Chen D, Reierstad S, Lu M, Lin Z, Ishikawa H, Bulun SE. Regulation of breast cancer-associated aromatase promoters. Cancer Lett 2008; 273:15-27. [PMID: 18614276 DOI: 10.1016/j.canlet.2008.05.038] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Revised: 05/23/2008] [Accepted: 05/28/2008] [Indexed: 01/28/2023]
Abstract
By converting androstenedione to estrone, or testosterone to estradiol, aromatase is a key enzyme in estrogen biosynthesis. Encoded by a single gene CYP19, aromatase is expressed in various tissues, including ovary, placenta, bone, brain, skin, and adipose tissue, via partially tissue-specific promoters, and is essential for normal estrogen-dependent physiological functions. In disease-free breast tissue, aromatase mRNA is primarily transcribed from the weak promoter I.4 and maintained at low levels in breast adipose stromal fibroblasts. In breast cancer a distinct set of aromatase promoters, i.e. I.3, II, and I.7, is activated, leading to a marked increase in aromatase expression in breast tumors and breast adipose tissue adjacent to a breast tumor, and a consequent local overproduction of estrogen that promotes growth and progression of breast cancer. In addition, the total amount of promoter I.4-specific aromatase transcript in breast adipose fibroblasts may also be increased due to both cytokine-induced desmoplastic reaction and cytokine-stimulated promoter I.4 activity in breast cancer. Targeting aromatase has proven beneficial in treating breast cancer, since aromatase inhibitors are the most effective endocrine treatment of breast cancer to date. However, aromatase inhibitors cause major side effects such as bone loss and abnormal lipid metabolism, due to indiscriminate reduction of aromatase activity in all expression sites of the body. Therefore, inhibition of aromatase expression via breast cancer-associated aromatase promoters is a useful strategy to selectively block local aromatase production, and hence estrogen synthesis, in breast cancer. This review will summarize the significant findings on regulation of the breast cancer-associated aromatase promoters, and highlight the discovery of chemical compounds and nuclear receptor ligands that specifically inhibit activation of these aromatase promoters. Clinical side effects of these agents require development of new drugs with better specificity and efficacy, and epigenetic therapies with breast cancer tissue-selective aromatase siRNA-conjugated nanoparticles.
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Affiliation(s)
- Dong Chen
- Division of Reproductive Biology Research, Department of Obstetrics and Gynecology, Northwestern University, 303 E Superior Street, Chicago, IL 60611, USA.
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74
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Wang Y, Ye L, Leung LK. A positive feedback pathway of estrogen biosynthesis in breast cancer cells is contained by resveratrol. Toxicology 2008; 248:130-5. [PMID: 18462857 DOI: 10.1016/j.tox.2008.03.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2008] [Revised: 03/19/2008] [Accepted: 03/24/2008] [Indexed: 10/22/2022]
Abstract
Cytochrome P450 (CYP) 19 enzyme or aromatase catalyses the rate-determining step of estrogen synthesis. The transcriptional control of CYP19 gene is highly specific in different cell types, for instance, Promoter I.3/II is commonly used for regulation in breast cancer cells. Recently, a positive feedback pathway for estrogen synthesis has been identified in ER alpha expressing SK-BR-3 cells. CYP19 mRNA abundance and activity are increased in this pathway and the promoter usage is switched from Promoter I.3/II to I.1 through a non-genomic process. In the present study, effect of the phytocompound resveratrol on this Promoter I.1-controlled expression of aromatase was investigated. Results indicated that resveratrol reduced the estradiol-induced mRNA abundance in SK-BR-3 cells expressing ER alpha. Luciferase reporter gene assays revealed that resveratrol could also repress the transcriptional control dictated by Promoter I.1. Since the ERE-driven luciferase activity was not repressed by resveratrol, the nuclear events of estrogen were unlikely to be suppressed by resveratrol. Instead the phytochemical reduced the amount of ERK activated by estradiol, which could be the pathway responsible for Promoter I.1 transactivation and the induced CYP19 expression. The present study illustrated that resveratrol impeded the non-genomic induction of estrogen on CYP19.
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Affiliation(s)
- Yun Wang
- Department of Biochemistry, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, China
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75
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Ishikawa H, Fenkci V, Marsh EE, Yin P, Chen D, Cheng YH, Reisterd S, Lin Z, Bulun SE. CCAAT/enhancer binding protein beta regulates aromatase expression via multiple and novel cis-regulatory sequences in uterine leiomyoma. J Clin Endocrinol Metab 2008; 93:981-91. [PMID: 18182446 PMCID: PMC2266947 DOI: 10.1210/jc.2007-2507] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Control of aromatase expression in uterine leiomyoma has significant clinical implications because aromatase inhibitors reduce tumor growth and associated irregular uterine bleeding. The mechanisms that regulate aromatase expression in leiomyoma are unknown. OBJECTIVES We previously demonstrated that the cAMP-responsive proximal promoters I.3 and II regulate aromatase expression in vivo in uterine leiomyoma tissue. Here, we investigated the cellular and molecular mechanisms responsible for promoter I.3/II usage. RESULTS In smooth muscle cells isolated from leiomyoma (LSMCs), dibutyryl cAMP significantly induced aromatase mRNA and enzyme activity. Reporter constructs of promoter I.3/II deletion and site-directed mutants with selective disruption of cis-regulatory elements in the -517/-16 bp region revealed that five out of seven elements, including three CCAAT/enhancer binding protein (C/EBP) binding sites and two cAMP response elements, were essential for cAMP-induced promoter activity. EMSAs demonstrated that nuclear extracts from LSMCs contain complexes assembled on four of the five cis-elements, with C/EBP binding sites, including a novel -245/-231 bp sequence, clearly associating with C/EBPbeta. Chromatin immunoprecipitation assays revealed that C/EBPbeta binds specifically to the promoter I.3/II region in intact cells. Dibutyryl cAMP significantly induced nuclear C/EBPbeta protein levels in LSMCs in a time-dependent manner. Conversely, knockdown of C/EBPbeta dramatically suppressed cAMP-induced aromatase mRNA and enzyme activity. CONCLUSIONS C/EBPbeta, which binds to multiple cis-regulatory elements in promoter I.3/II, is a key factor in the transcriptional complex controlling aromatase expression in uterine leiomyoma cells. Definition of this mechanism further may assist in designing inhibitors of aromatase specific for leiomyoma tissue.
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Affiliation(s)
- Hiroshi Ishikawa
- Division of Reproductive Biology Research, Feinberg School of Medicine at Northwestern University, 303 Superior Street, Suite 4-123, Chicago, Illinois 60611, USA
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76
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McInnes KJ, Brown KA, Knower KC, Chand AL, Clyne CD, Simpson ER. Characterisation of aromatase expression in the human adipocyte cell line SGBS. Breast Cancer Res Treat 2008; 112:429-35. [DOI: 10.1007/s10549-007-9883-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2007] [Accepted: 12/20/2007] [Indexed: 10/22/2022]
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77
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Bulun SE, Simpson ER. Aromatase expression in women's cancers. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2008; 630:112-32. [PMID: 18637488 DOI: 10.1007/978-0-387-78818-0_8] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Estrogen has been positively linked to the pathogenesis and growth of three common women's cancers (breast, endometrium and ovary). A single gene encodes the key enzyme for estrogen biosynthesis named aromatase, inhibition of which effectively eliminates estrogen production in the entire body. Aromatase inhibitors successfully treat breast cancer, whereas their roles in endometrial and ovarian cancers are less dear. Ovary, testis, adipose tissue, skin, hypothalamus and placenta express aromatase normally, whereas breast, endometrial and ovarian cancers overexpress aromatase and produce local estrogen exerting paracrine and intracrine effects. Tissue specific promoters distributed over a 93 kilobase regulatory region upstream of a common coding region alternatively control aromatase expression. A distinct set of transcription factors regulates each promoter in a signaling pathway- and tissue-specific manner. In cancers ofbreast, endometrium and ovary, aromatase expression is primarly regulated by increased activity of the proximally located promoter 1.3/II region. Promoters I.3 and II lie 215 bp from each other and are coordinately stimulated by PGE2 via a cAMP-PKA-dependent pathway. In breast adipose fibroblasts exposed to PGE2 secreted by malignant epithelial cells, activation of PKC potentiates cAMP-PKA-dependent induction ofaromatase. Thus, inflammatory substances such as PGE2 may play important roles in inducing local production of estrogen that promotes tumor growth.
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Affiliation(s)
- Serdar E Bulun
- Department of Obstetric and Gynecology, Northwestern University, Chicago, IL 60611, USA.
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78
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Abstract
Osteoporosis is a prevalent disease with a strong genetic component. Estrogens play a critical role in bone homeostasis. The aromatization of androgenic precursors is the main source of estrogens in men and postmenopausal women. Thus, aromatase is an attractive osteoporosis candidate gene. In this paper the influence of aromatase activity and aromatase gene variants on skeletal homeostasis is reviewed. The results of studies regarding the association between some common polymorphisms of the aromatase gene and bone mineral density and the risk of osteoporotic fractures are described. The mechanisms involved and the potential usefulness of those genetic data in the prevention and management of osteoporosis are discussed.
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Affiliation(s)
- José A Riancho
- University of Cantabria, Department of Internal Medicine, Hospital U.M. Valdecilla, Av Valdecilla sn, 39008 Santander, Spain.
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79
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Ohmuro-Matsuyama Y, Okubo K, Matsuda M, Ijiri S, Wang D, Guan G, Suzuki T, Matsuyama M, Morohashi KI, Nagahama Y. Liver receptor homologue-1 (LRH-1) activates the promoter of brain aromatase (cyp19a2) in a teleost fish, the medaka, Oryzias latipes. Mol Reprod Dev 2007; 74:1065-71. [PMID: 17394235 DOI: 10.1002/mrd.20497] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The medaka, Oryzias latipes, like other fish, have two distinct aromatase genes, the ovarian (cyp19a1) and brain (cyp19a2) forms. We previously reported that Ad4BP/SF-1, a member of the NR5A subfamily, plays an important role in the regulation of cyp19a1 expression in medaka ovarian follicles during vitellogenesis. In the present study, we investigated whether liver receptor homologue-1 (LRH-1), another NR5A subfamily member, is involved in the regulation of cyp19a2 expression in the medaka brain. In situ hybridization analysis revealed that LRH-1 was expressed in the hypothalamus, where it colocalized with aromatase (cyp19a2). We then showed by transient transfection assays that LRH-1 was able to increase expression of a cyp19a2 reporter gene in various mammalian cell lines, and that mutation of a putative LRH-1 binding site within the cyp19a2 promoter abolished this effect. Taken together, these findings suggest that LRH-1 plays a role in regulating cyp19a2 expression in the medaka brain. This is the first to demonstrate in vitro the activation of brain aromatase by LRH-1 in the vertebrate brain.
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Affiliation(s)
- Yuki Ohmuro-Matsuyama
- Department of Basic Biology, The Graduate University for Advanced Studies, Okazaki, Japan
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80
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Oestrogen producing enzymes and mammary carcinogenesis: a review. Breast Cancer Res Treat 2007; 111:191-202. [DOI: 10.1007/s10549-007-9788-0] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2007] [Accepted: 10/05/2007] [Indexed: 10/22/2022]
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81
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Amar S, Roy V, Perez EA. Letrozole: present and future role in the treatment of breast cancer. Expert Opin Pharmacother 2007; 8:1965-75. [PMID: 17696797 DOI: 10.1517/14656566.8.12.1965] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
State of the art hormonal therapy for women with breast cancer has evolved over the last few years. Tamoxifen used to be the gold standard for adjuvant treatment of postmenopausal women with hormone-sensitive early breast cancer and also for patients with metastatic disease in whom hormonal manipulation was considered, but the introduction of third generation aromatase inhibitors has changed this concept. This article discusses the clinical implications of recent trials with one of the aromatase inhibitors letrozole, including pharmacokinetic and pharmacodynamic data as well as recent data on relative benefits and side effects compared with other available hormonal agents. Relevant ongoing clinical-translational trials evaluating this agent are also discussed.
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82
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Bulun SE, Chen D, Lu M, Zhao H, Cheng Y, Demura M, Yilmaz B, Martin R, Utsunomiya H, Thung S, Su E, Marsh E, Hakim A, Yin P, Ishikawa H, Amin S, Imir G, Gurates B, Attar E, Reierstad S, Innes J, Lin Z. Aromatase excess in cancers of breast, endometrium and ovary. J Steroid Biochem Mol Biol 2007; 106:81-96. [PMID: 17590327 PMCID: PMC2766613 DOI: 10.1016/j.jsbmb.2007.05.027] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Pathogenesis and growth of three common women's cancers (breast, endometrium and ovary) are linked to estrogen. A single gene encodes the key enzyme for estrogen biosynthesis named aromatase, inhibition of which effectively eliminates estrogen production in the entire body. Aromatase inhibitors successfully treat breast cancer, whereas their roles in endometrial and ovarian cancers are less clear. Ovary, testis, adipose tissue, skin, hypothalamus and placenta express aromatase normally, whereas breast, endometrial and ovarian cancers overexpress aromatase and produce local estrogen exerting paracrine and intracrine effects. Tissue-specific promoters distributed over a 93-kb regulatory region upstream of a common coding region alternatively control aromatase expression. A distinct set of transcription factors regulates each promoter in a signaling pathway- and tissue-specific manner. In cancers of breast, endometrium and ovary, aromatase expression is primarly regulated by increased activity of the proximally located promoter I.3/II region. Promoters I.3 and II lie 215 bp from each other and are coordinately stimulated by PGE(2) via a cAMP-PKA-dependent pathway. In breast adipose fibroblasts exposed to PGE(2) secreted by malignant epithelial cells, PKC is also activated, and this potentiates cAMP-PKA-dependent induction of aromatase. Thus, inflammatory substances such as PGE(2) may play important roles in inducing local production of estrogen that promotes tumor growth.
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Affiliation(s)
- Serdar E Bulun
- Robert H. Lurie Comprehensive Cancer Center and Division of Reproductive Biology Research, Department of Obstetrics and Gynecology, Northwestern University, Chicago, IL 60611, USA.
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83
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Bhanoori M, Deenadayal M, Kennedy S, Shivaji S. The G2964A 3'-untranslated region polymorphism of the signal transducer and activator of transcription 6 gene is associated with endometriosis in South Indian women. Hum Reprod 2007; 22:1026-30. [PMID: 17213269 DOI: 10.1093/humrep/del486] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND The aim of the study was to test whether the signal transducer and activator of transcription 6 (STAT6) gene influences the risk of developing endometriosis. METHODS The single-nucleotide polymorphism, G2964A, in the 3'-untranslated region (UTR) of the STAT6 gene was tested for association in a case-control study of 232 affected women and 210 women with no evidence of disease. All the women were infertile, ascertained from the same infertility clinic and of South Indian origin. The genotype frequencies of this polymorphism were compared using PCR and sequencing analysis. RESULTS There were statistically significant differences in the genotype distributions (P = 0.002) and allele frequencies (P = 0.0002) between the cases and controls, according to codominant, dominant and recessive genotype models. CONCLUSIONS We report for the first time an association between the STAT6 G2964A 3'-UTR polymorphism and endometriosis in South Indian women. This finding suggests that STAT6 may contribute to disease susceptibility in endometriosis, which carries an extra interest as the gene lies in a region which has been implicated, albeit weakly, in a previous genomewide scan.
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Affiliation(s)
- Manjula Bhanoori
- Centre for Cellular and Molecular Biology, Hyderabad, Andhra Pradesh, India
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Williams TD, Diab AM, George SG, Sabine V, Chipman JK. Gene expression responses of European flounder (Platichthys flesus) to 17-beta estradiol. Toxicol Lett 2006; 168:236-48. [PMID: 17156945 DOI: 10.1016/j.toxlet.2006.10.020] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2006] [Accepted: 10/09/2006] [Indexed: 12/01/2022]
Abstract
Male European flounder (Platichthys flesus) were intraperitoneally injected with 10mg/kg 17-beta estradiol and tissues taken from individuals over a timecourse of 16 days. The GENIPOL P. flesus cDNA microarray was employed to detect hepatic gene expression differences between fish treated with estradiol and saline controls. Known biomarkers of estrogen exposure, choriogenin L and vitellogenins, showed sustained induction over the time-course. Among 175 identified clones showing sustained statistically significant induction or repression, those associated with the Gene Ontology terms mitochondria, amino acid synthesis, ubiquitination and apoptosis were included amongst those induced while those associated with immune function, electron transport, cell signalling and protein phosphorylation were repressed. Thus, we show the gene expression response of an environmentally relevant fish species to a high dose of an estrogenic endocrine disruptor and also report the sequencing of a further 2121 flounder ESTs.
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Affiliation(s)
- Tim D Williams
- School of Biosciences, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
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85
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Mikolajczyk M, Wirstlein P, Skrzypczak J. Leukaemia inhibitory factor and interleukin 11 levels in uterine flushings of infertile patients with endometriosis. Hum Reprod 2006; 21:3054-8. [PMID: 17000646 DOI: 10.1093/humrep/del225] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Exact aetiology of infertility in stage I/II endometriosis patients is not known. Interleukin 11 (IL-11) and leukaemia-inhibitory factor (LIF) are factors associated with implantation window in human eutopic endometrium. We decided to test whether there is an altered secretion of these factors, which could explain receptivity defect in patients with minimal endometriosis. METHODS Uterine flushing and endometrial samples were collected 7-9 days after ovulation (implantation window) from infertile patients with stage I/II endometriosis (n = 14) and fertile, endometriosis-free controls (n = 21). IL-11 and LIF were assessed in uterine flushings in eutopic endometria in all patients by enzyme-linked immunosorbent assay (ELISA). In eutopic endometrium, semiquantitative RT-PCR was performed for LIF and IL-11 mRNA expressions. RESULTS No statistically significant differences were found in uterine flushing in women with and without endometriosis with regard to IL-11 levels (0.0 pg/ml versus 0.0 pg/ml) and LIF (25.53 pg/ml versus 36.26 pg/ml). These results were confirmed by the results of RT-PCR, where there were also no differences between studied groups. CONCLUSIONS There is no receptivity defect with regard to LIF and IL-11 secretions by eutopic endometrium in infertile women with endometriosis.
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Affiliation(s)
- M Mikolajczyk
- Department of Obstetrics and Gynecology, Division of Reproduction, University of Medical Sciences, Poznan, Poland
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86
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Kalsotra A, Strobel HW. Cytochrome P450 4F subfamily: at the crossroads of eicosanoid and drug metabolism. Pharmacol Ther 2006; 112:589-611. [PMID: 16926051 DOI: 10.1016/j.pharmthera.2006.03.008] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2006] [Accepted: 03/22/2006] [Indexed: 12/13/2022]
Abstract
The cytochrome P450 4F (CYP4F) subfamily has over the last few years come to be recognized for its dual role in modulating the concentrations of eicosanoids during inflammation as well as in the metabolism of clinically significant drugs. The first CYP4F was identified because it catalyzed the hydroxylation of leukotriene B(4) (LTB(4)) and since then many additional members of this subfamily have been documented for their distinct catalytic roles and functional significance. Recent evidence emerging in relation to the temporal change of CYP4F expression in response to injury and infection supports an important function for these isozymes in curtailing inflammation. Their tissue-dependent expression, isoform-based catalytic competence and unique response to the external stimuli imply a critical role for them to regulate organ-specific functions. From this standpoint variations in relative CYP4F levels in humans may have direct influence on the metabolic outcome through their ability to generate and/or degrade bioactive eicosanoids or therapeutic agents. This review covers the enzymatic characteristics and regulatory properties of human and rodent CYP4F isoforms and their physiological relevance to major pathways in eicosanoid and drug metabolism.
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Affiliation(s)
- Auinash Kalsotra
- Department of Biochemistry and Molecular Biology, The University of Texas-Houston Medical School, P.O. Box 20708, 6431 Fannin Street Houston, TX 77225, USA
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87
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Kijima I, Phung S, Hur G, Kwok SL, Chen S. Grape seed extract is an aromatase inhibitor and a suppressor of aromatase expression. Cancer Res 2006; 66:5960-7. [PMID: 16740737 DOI: 10.1158/0008-5472.can-06-0053] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Aromatase is the enzyme that converts androgen to estrogen. It is expressed at higher levels in breast cancer tissues than normal breast tissues. Grape seed extract (GSE) contains high levels of procyanidin dimers that have been shown in our laboratory to be potent inhibitors of aromatase. In this study, GSE was found to inhibit aromatase activity in a dose-dependent manner and reduce androgen-dependent tumor growth in an aromatase-transfected MCF-7 (MCF-7aro) breast cancer xenograft model, agreeing with our previous findings. We have also examined the effect of GSE on aromatase expression. Reverse transcription-PCR experiments showed that treatment with 60 mug/mL of GSE suppressed the levels of exon I.3-, exon PII-, and exon I.6-containing aromatase mRNAs in MCF-7 and SK-BR-3 cells. The levels of exon I.1-containing mRNA, however, did not change with GSE treatment. Transient transfection experiments with luciferase-aromatase promoter I.3/II or I.4 reporter vectors showed the suppression of the promoter activity in a dose-dependent manner. The GSE treatment also led to the down-regulation of two transcription factors, cyclic AMP-responsive element binding protein-1 (CREB-1) and glucocorticoid receptor (GR). CREB-1 and GR are known to up-regulate aromatase gene expression through promoters I.3/II and I.4, respectively. We believe that these results are exciting in that they show GSE to be potentially useful in the prevention/treatment of hormone-dependent breast cancer through the inhibition of aromatase activity as well as its expression.
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Affiliation(s)
- Ikuko Kijima
- Department of Surgical Research, Beckman Research Institute of the City of Hope, Duarte, California, USA
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88
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Chong YM, Colston K, Jiang WG, Sharma AK, Mokbel K. The relationship between the insulin-like growth factor-1 system and the oestrogen metabolising enzymes in breast cancer tissue and its adjacent non-cancerous tissue. Breast Cancer Res Treat 2006; 99:275-88. [PMID: 16752221 DOI: 10.1007/s10549-006-9215-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2006] [Accepted: 03/02/2006] [Indexed: 12/12/2022]
Abstract
AIMS Previous studies have shown that oestrogen and Insulin-like Growth Factor-1 (IGF-1) act synergistically and cross-stimulatory while the oestrogen receptor (ER) and IGF-1R downstream signalling pathways interact at many levels. We investigate the relationship between the ER, and IGF-1R and their ligands in a series of human breast cancer tissue and adjacent non-cancerous tissue (ANCT). METHODS A series of 139 pairs of breast cancer tissue and ANCT were obtained and divided into ER positive and ER negative groups based on tumour ER alpha immunostaining. All samples were processed for real-time quantitative-PCR to measure IGF-1, IGF-1R, ER alpha, STS and Cyp-19 mRNA levels. In addition, ER positive MCF-7 and ER negative MDA-MB-231 cell lines were treated separately with IGF-1 and an IGF-1R inhibitor called Tyrphostin AG1024 to see the effects of stimulating and inhibiting the IGF-1R. MCF-7 cell line was also treated with 4-hydroxytamoxifen. The mRNA levels of IGF-1, IGF-1R, ER alpha, STS and Cyp-19 of treated cell lines were measured and compared to those of non-treated controls. Data generated was normalised to Cytokeratin-19 mRNA levels. RESULTS IGF-1R expression was higher in tumour tissue compared to ANCT (P = 0.038) while IGF-1 expression was marginally higher in ANCT compared to tumour tissue only in the ER positive samples (P = 0.098). ER positive tumours had a higher expression of IGF-1 compared to ER negative tumours (P = 0.001) while IGF-1R, STS and Cyp-19 expression were higher in ER negative tumours (P = 0.000, 0.000 and 0.006 respectively). There was no difference in STS or Cyp-19 expression in tumours or ANCT. Using Spearman's Correlation test, IGF-1 positively correlated with STS, Cyp-19 and ER alpha in ER positive and negative groups (Coefficient = +0.497, +0.662 and +0.651 respectively, P = 0.000 in all). IGF-1R correlated with IGF-1, STS, Cyp-19 and ER alpha only in the ER negative tumours (Coefficient = +0.620, +0.394, +0.692 and +0.662 respectively, P = 0.000, 0.012, 0.000 and 0.000 respectively). In cell lines, IGF-1 treatment led to an increase in the mean expression of IGF-1, IGF-1R, STS and Cyp-19 in both cell lines while ER alpha expression increased only in MCF-7. IGF-1R inhibition caused a decrease in expression of all five genes in MDA-MB-231 but not in the MCF-7 cell line. Treatment with 4-hydroxytamoxifen caused a decrease in expression of all five genes. CONCLUSIONS IGF-1R is over-expressed in malignant tissue. IGF-1 is expressed at higher levels in ER positive tumours probably as a result of oestrogen stimulation while IGF-1R expression is higher in ER negative samples as an adaptation to lower local IGF-1 levels. An IGF-1 paracrine relationship may exist between tumour and ANCT but for STS and Cyp-19, there may be an autocrine-paracrine relationship. The IGF-1 ligand-receptor system is an important regulator of oestrogen production while oestrogen may be involved in stimulating IGF-1 expression. The expression of oestrogen synthesising enzymes is higher in ER negative breast cancers which may be due to the lack of oestrogen negative feedback or contribution from the overexpression of IGF-1R.
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Affiliation(s)
- Yoon Mann Chong
- Department of Cellular & Molecular Medicine, St George's Hospital, London, UK.
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89
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Dieudonné MN, Sammari A, Dos Santos E, Leneveu MC, Giudicelli Y, Pecquery R. Sex steroids and leptin regulate 11beta-hydroxysteroid dehydrogenase I and P450 aromatase expressions in human preadipocytes: Sex specificities. J Steroid Biochem Mol Biol 2006; 99:189-96. [PMID: 16621515 DOI: 10.1016/j.jsbmb.2006.01.007] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2005] [Accepted: 01/25/2006] [Indexed: 12/14/2022]
Abstract
Adipose tissue is an important site of steroid hormone biosynthesis, as type I 11beta-hydroxysteroid dehydrogenase (HSD1), the enzyme responsible for the conversion of cortisone into cortisol and the P450 aromatase, the enzyme catalysing androgens aromatization into estrogens, are both expressed in human adipose tissue. In the present report, we have investigated the possibility that sex steroids and leptin could regulate these two enzymes in cultured preadipocytes from men and women intra-abdominal fat depots. In women preadipocytes, human recombinant leptin down-regulates HSD1 mRNA expression (-58%) and P450 aromatase activity (-26%). Conversely, leptin up-regulates the HSD1 (2.4-fold) and the P450 aromatase (1.6-fold) mRNA expression in men preadipocytes. In women preadipocytes, 17beta-estradiol strongly stimulates HSD1 mRNA expression (10-fold) and, in contrast, decreases by half the P450 aromatase expression. In men, 17beta-estradiol has no influence on HSD1 expression but up-regulates P450 aromatase mRNA expression (2.4-fold). Finally, androgens increase by a factor of 2.5-5 the mRNA expression of both enzymes in men. These findings suggest that sex steroids and leptin either increase or decrease local cortisol and estrogens productions in men or in women preadipocytes, respectively. They also indicate that steroid metabolism in adipose tissue is controlled by a coordinated regulation of P450 aromatase and HSD1 expressions. Finally, the important sex-specific differences described herein may also contribute to explain the sexual dimorphism of body fat distribution in humans.
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Affiliation(s)
- Marie-Noëlle Dieudonné
- Service de Biochimie et de Biologie Moléculaire, UPRES EA 2493, Faculté de Médecine Paris-Ile de France-Ouest, Université Versailles St Quentin, Centre Hospitalier de Poissy, 78303 Poissy Cedex, France
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90
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Abstract
The aromatase enzyme is unique to the pathway of oestrogen biosynthesis and converts androgen precursors into oestrogens, major stimulatory factors for breast cancer proliferation. Although there is only a single gene for aromatase and a single protein for the enzyme, transcriptional control is complex using different promoters which are in part tissue-specific. These generate different mRNA transcripts that vary in the presence/absence of individual untranslated exon 1s. In breast cancers, species vary between individual tumours, types I.3 and I.4 being the major species in some tumours but type II predominates in the majority. Since the type II promoter is regulated by prostaglandins/cyclic AMP, agents signalling through these systems seem largely responsible for local regulation of intratumoural oestrogen biosynthesis. Autocrine production of these factors would account for the high activity in breast cancers and paracrine secretion for the raised activity in breast fat associated with the local presence of cancer. Given the central role of oestrogen in normal development and pathological processes, there has been great interest in controlling aromatase activity by the use of specific inhibitors. Clinically, this is particularly evident in the management of postmenopausal women with breast cancer.
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Affiliation(s)
- W R Miller
- Breast Unit Research Group, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, Scotland, UK.
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91
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Deb S, Zhou J, Jianfeng Z, Amin SA, Imir AG, Gonca IA, Yilmaz MB, Bertan YM, Lin Z, Zihong L, Bulun SE. A novel role of sodium butyrate in the regulation of cancer-associated aromatase promoters I.3 and II by disrupting a transcriptional complex in breast adipose fibroblasts. J Biol Chem 2005; 281:2585-97. [PMID: 16303757 DOI: 10.1074/jbc.m508498200] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The aromatase gene encodes the key enzyme for estrogen formation. Aromatase enzyme inhibitors eliminate total body estrogen production and are highly effective therapeutics for postmenopausal breast cancer. A distal promoter (I.4) regulates low levels of aromatase expression in tumor-free breast adipose tissue. Two proximal promoters (I.3/II) strikingly induce in vivo aromatase expression in breast fibroblasts surrounding malignant cells. Treatment of breast fibroblasts with medium conditioned with malignant breast epithelial cells (MCM) or a surrogate hormonal mixture (dibutyryl (Bt2)cAMP plus phorbol diacetate (PDA)) induces promoters I.3/II. The mechanism of promoter-selective expression, however, is not clear. Here we reported that sodium butyrate profoundly decreased MCM- or Bt2cAMP + PDA-induced promoter I.3/II-specific aromatase mRNA. MCM, Bt2cAMP + PDA, or sodium butyrate regulated aromatase mRNA or activity only via promoters I.3/II but not promoters I.1 or I.4 in breast, ovarian, placental, and hepatic cells. Mechanistically, recruitment of phosphorylated ATF-2 by a CRE (-211/-199, promoter I.3/II) conferred inductions by MCM or Bt2cAMP + PDA. Chromatin immunoprecipitation-PCR and immunoprecipitation-immunoblotting assays indicated that MCM or Bt2cAMP + PDA stabilized a complex composed of phosphorylated ATF-2, C/EBPbeta, and cAMP-response element-binding protein (CREB)-binding protein in the common regulatory region of promoters I.3/II. Overall, histone acetylation patterns of promoters I.3/II did not correlate with sodium butyrate-dependent silencing of promoters I.3/II. Sodium butyrate, however, consistently disrupted the activating complex composed of phosphorylated ATF-2, C/EBPbeta, and CREB-binding protein. This was mediated, in part, by decreased ATF-2 phosphorylation. Together, these findings represent a novel mechanism of sodium butyrate action and provide evidence that aromatase activity can be ablated in a signaling pathway- and cell-specific fashion.
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Affiliation(s)
- Santanu Deb
- Division of Reproductive Biology Research, Northwestern University, Chicago, Illinois 60611, USA
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92
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Bulun SE, Lin Z, Imir G, Amin S, Demura M, Yilmaz B, Martin R, Utsunomiya H, Thung S, Gurates B, Tamura M, Langoi D, Deb S. Regulation of aromatase expression in estrogen-responsive breast and uterine disease: from bench to treatment. Pharmacol Rev 2005; 57:359-83. [PMID: 16109840 DOI: 10.1124/pr.57.3.6] [Citation(s) in RCA: 394] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
A single gene encodes the key enzyme for estrogen biosynthesis termed aromatase, inhibition of which effectively eliminates estrogen production. Aromatase inhibitors successfully treat breast cancer and endometriosis, whereas their roles in endometrial cancer, uterine fibroids, and aromatase excess syndrome are less clear. Ovary, testis, adipose tissue, skin, hypothalamus, and placenta express aromatase normally, whereas breast and endometrial cancers, endometriosis, and uterine fibroids overexpress aromatase and produce local estrogen that exerts paracrine and intracrine effects. Tissue-specific promoters distributed over a 93-kilobase regulatory region upstream of a common coding region alternatively control aromatase expression. A distinct set of transcription factors regulates each promoter in a signaling pathway- and tissue-specific manner. Three mechanisms are responsible for aromatase overexpression in a pathologic tissue versus its normal counterpart. First, cellular composition is altered to increase aromatase-expressing cell types that use distinct promoters (breast cancer). Second, molecular alterations in stromal cells favor binding of transcriptional enhancers versus inhibitors to a normally quiescent aromatase promoter and initiate transcription (breast/endometrial cancer, endometriosis, and uterine fibroids). Third, heterozygous mutations, which cause the aromatase coding region to lie adjacent to constitutively active cryptic promoters that normally transcribe other genes, result in excessive estrogen formation owing to the overexpression of aromatase in many tissues.
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Affiliation(s)
- Serdar E Bulun
- Division of Reproductive Biology Research, Department of Obstetric and Gynecology, Northwestern University, Chicago, IL 60611, USA.
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93
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Attar E, Bulun SE. Aromatase and other steroidogenic genes in endometriosis: translational aspects. Hum Reprod Update 2005; 12:49-56. [PMID: 16123052 DOI: 10.1093/humupd/dmi034] [Citation(s) in RCA: 169] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Endometriosis is a common, chronic and estrogen-dependent gynaecological disorder associated with pelvic pain and infertility. In addition to, or perhaps as a consequence of, immune, environmental and genetic factors, endometriotic lesions show high estradiol (E(2)) biosynthesis and low E(2) inactivation compared with normal endometrium. Current medical therapies of pain, which aim to lower circulating E(2) concentrations, are not effective in at least half of these patients. We and others recently demonstrated the expression of a few steroidogenic genes in endometriosis. The most important genes in this group are steroidogenic acute regulatory protein (StAR) and aromatase. Both are essential for E(2) production. Prostaglandin E(2) (PGE(2)) is the most potent known stimulator of both StAR and aromatase. PGE(2) production in endometriosis is up-regulated by increased levels of the enzyme cyclo-oxygenase-2 (COX-2) in this tissue. COX-2 in turn is stimulated by E(2), interleukin-1beta (IL-1beta) and PGE(2) itself in endometrial and endometriotic cells. Thus, there is a positive feedback loop that favours continuous formation of E(2) and PGE(2) in endometriosis. These basic findings led to recent phase-II studies employing aromatase inhibitors in the treatment of endometriosis. Aromatase inhibitors treat both postmenopausal and premenopausal endometriosis at least as effectively as the existing medical treatments. In premenopausal women, we and others administered aromatase inhibitors in combination with an ovarian-suppressant treatment. In this review, we emphasize the most recent basic studies in detail and provide a short summary of recent clinical trials.
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Affiliation(s)
- E Attar
- Division of Reproductive Biology Research, Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
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Simard J, Ricketts ML, Gingras S, Soucy P, Feltus FA, Melner MH. Molecular biology of the 3beta-hydroxysteroid dehydrogenase/delta5-delta4 isomerase gene family. Endocr Rev 2005; 26:525-82. [PMID: 15632317 DOI: 10.1210/er.2002-0050] [Citation(s) in RCA: 390] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The 3beta-hydroxysteroid dehydrogenase/Delta(5)-Delta(4) isomerase (3beta-HSD) isoenzymes are responsible for the oxidation and isomerization of Delta(5)-3beta-hydroxysteroid precursors into Delta(4)-ketosteroids, thus catalyzing an essential step in the formation of all classes of active steroid hormones. In humans, expression of the type I isoenzyme accounts for the 3beta-HSD activity found in placenta and peripheral tissues, whereas the type II 3beta-HSD isoenzyme is predominantly expressed in the adrenal gland, ovary, and testis, and its deficiency is responsible for a rare form of congenital adrenal hyperplasia. Phylogeny analyses of the 3beta-HSD gene family strongly suggest that the need for different 3beta-HSD genes occurred very late in mammals, with subsequent evolution in a similar manner in other lineages. Therefore, to a large extent, the 3beta-HSD gene family should have evolved to facilitate differential patterns of tissue- and cell-specific expression and regulation involving multiple signal transduction pathways, which are activated by several growth factors, steroids, and cytokines. Recent studies indicate that HSD3B2 gene regulation involves the orphan nuclear receptors steroidogenic factor-1 and dosage-sensitive sex reversal adrenal hypoplasia congenita critical region on the X chromosome gene 1 (DAX-1). Other findings suggest a potential regulatory role for STAT5 and STAT6 in transcriptional activation of HSD3B2 promoter. It was shown that epidermal growth factor (EGF) requires intact STAT5; on the other hand IL-4 induces HSD3B1 gene expression, along with IL-13, through STAT 6 activation. However, evidence suggests that multiple signal transduction pathways are involved in IL-4 mediated HSD3B1 gene expression. Indeed, a better understanding of the transcriptional factors responsible for the fine control of 3beta-HSD gene expression may provide insight into mechanisms involved in the functional cooperation between STATs and nuclear receptors as well as their potential interaction with other signaling transduction pathways such as GATA proteins. Finally, the elucidation of the molecular basis of 3beta-HSD deficiency has highlighted the fact that mutations in the HSD3B2 gene can result in a wide spectrum of molecular repercussions, which are associated with the different phenotypic manifestations of classical 3beta-HSD deficiency and also provide valuable information concerning the structure-function relationships of the 3beta-HSD superfamily. Furthermore, several recent studies using type I and type II purified enzymes have elegantly further characterized structure-function relationships responsible for kinetic differences and coenzyme specificity.
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Affiliation(s)
- Jacques Simard
- Cancer Genomics Laboratory, T3-57, Laval University Medical Center (CHUL) Research Center, 2705 Laurier Boulevard, Québec City, Québec, Canada.
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95
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Kamali-Sarvestani E, Gharesi-Fard B, Sarvari J, Talei AAR. Association of TNF-alpha and TNF-beta gene polymorphism with steroid receptor expression in breast cancer patients. Pathol Oncol Res 2005; 11:99-102. [PMID: 15999154 DOI: 10.1007/bf02893375] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2005] [Accepted: 04/20/2005] [Indexed: 11/25/2022]
Abstract
The presence of estrogen and progesterone receptors is correlated with good prognosis in breast cancer. The effect of TNF-alpha on down-regulation of estrogen receptor and blocking the proliferative response of breast cancer cells to estradiol have been demonstrated. However, the effect of TNFA and TNFB gene polymorphisms on the expression of steroid receptors in breast cancer cells is not well documented. Therefore, 160 breast cancer patients were recruited to investigate the association of TNFA and TNFB gene polymorphism with the level of steroid receptor expression. This association was not found to be significant for TNFA polymorphism and estrogen receptor expression (p=0.07). However, when combined genotypes of TNFA and TNFB polymorphism was considered, homozygous patients for lower TNF-alpha producer genotypes (TNFA1/A1 and TNFB1/B1) showed significantly higher progesterone receptor expression (p=0.041). Our findings indicate that TNFA and TNFB polymorphisms may be associated with the levels of steroid receptor expression in breast cancer patients. Further studies on a larger group of breast cancer patients are recommended.
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96
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Abstract
Oestrogens are heavily implicated in the risk to, and progression of, breast cancer. Therapeutic strategies targeted at the oestrogenic stimulus to the breast and hormone-sensitive breast cancers are extremely attractive measures both to prevent the disease and to treat established tumours. The present review outlines the biological rationale for such endocrine therapy and traces the evolution whereby irreversible surgical procedures have been replaced by potent and specific drugs. In particular, the development of the latest generation of agents which inhibit oestrogen biosynthesis (aromatase inhibitors) is considered by defining the central role of the aromatase enzyme, its regulation and contribution to circulating and tumour endogenous oestrogens. The nature of response and resistance which may be elicited following the use of endocrine therapy is also described as this may determine the optimal use of aromatase inhibitors and, more generally, anti-hormone therapy in the management of women at high risk to, or with, breast cancer.
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Affiliation(s)
- W R Miller
- Edinburgh Breast Unit Research Group, Western General Hospital, University of Edinburgh, Paderewski Building, Edinburgh EH4 2XU, Scotland, UK.
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97
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Clyne CD, Kovacic A, Speed CJ, Zhou J, Pezzi V, Simpson ER. Regulation of aromatase expression by the nuclear receptor LRH-1 in adipose tissue. Mol Cell Endocrinol 2004; 215:39-44. [PMID: 15026173 DOI: 10.1016/j.mce.2003.11.001] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Aromatase is the enzyme responsible for estrogen production, and is the product of the CYP19 gene. This gene is under the control of many tissue-specific promoters, each of which is regulated by different cohorts of factors. In normal breast adipose tissue, relatively low levels of aromatase are expressed via the action of the adipose specific promoter I.4. Breast tumor-derived factors such as prostaglandin E(2) (PGE(2)) strongly stimulate aromatase expression via an alternative promoter, promoter II, leading to increased estrogenic drive and tumor growth. Understanding the mechanisms that regulate promoter II activity in tumorous breast may therefore identify new targets for breast cancer drug discovery. The current study describes the role of the orphan nuclear receptor LRH-1 and its co-regulators in modulating aromatase expression in breast adipose tissue.
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Affiliation(s)
- Colin D Clyne
- Prince Henry's Institute of Medical Research, PO Box 5152, Clayton, Vic. 3168, Australia.
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98
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Bruun JM, Lihn AS, Verdich C, Pedersen SB, Toubro S, Astrup A, Richelsen B. Regulation of adiponectin by adipose tissue-derived cytokines: in vivo and in vitro investigations in humans. Am J Physiol Endocrinol Metab 2003; 285:E527-33. [PMID: 12736161 DOI: 10.1152/ajpendo.00110.2003] [Citation(s) in RCA: 496] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Adiponectin is an adipose tissue-specific protein that is abundantly present in the circulation and suggested to be involved in insulin sensitivity and development of atherosclerosis. Because cytokines are suggested to regulate adiponectin, the aim of the present study was to investigate the interaction between adiponectin and three adipose tissue-derived cytokines (IL-6, IL-8, and TNF-alpha). The study was divided into three substudies as follows: 1) plasma adiponectin and mRNA levels in adipose tissue biopsies from obese subjects [mean body mass index (BMI): 39.7 kg/m2, n = 6] before and after weight loss; 2) plasma adiponectin in obese men (mean BMI: 38.7 kg/m2, n = 19) compared with lean men (mean BMI: 23.4 kg/m2, n = 10) before and after weight loss; and 3) in vitro direct effects of IL-6, IL-8, and TNF-alpha on adiponectin mRNA levels in adipose tissue cultures. The results were that 1) weight loss resulted in a 51% (P < 0.05) increase in plasma adiponectin and a 45% (P < 0.05) increase in adipose tissue mRNA levels; 2) plasma adiponectin was 53% (P < 0.01) higher in lean compared with obese men, and plasma adiponectin was inversely correlated with adiposity, insulin sensitivity, and IL-6; and 3) TNF-alpha (P < 0.01) and IL-6 plus its soluble receptor (P < 0.05) decreased adiponectin mRNA levels in vitro. The inverse relationship between plasma adiponectin and cytokines in vivo and the cytokine-induced reduction in adiponectin mRNA in vitro suggests that endogenous cytokines may inhibit adiponectin. This could be of importance for the association between cytokines (e.g., IL-6) and insulin resistance and atherosclerosis.
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Affiliation(s)
- Jens M Bruun
- Department of Endocrinology and Metabolism C, Aarhus Amtssygehus, Aarhus University Hospital, Denmark.
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Underhill-Day N, McGovern LA, Karpovich N, Mardon HJ, Barton VA, Heath JK. Functional characterization of W147A: a high-affinity interleukin-11 antagonist. Endocrinology 2003; 144:3406-14. [PMID: 12865319 PMCID: PMC1626581 DOI: 10.1210/en.2002-0144] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
IL-11 is a member of the gp130 family of cytokines, which signal via assembly of multisubunit receptor complexes containing at least one molecule of the transmembrane signaling receptor gp130. IL-11 forms a high-affinity complex, thereby inducing gp130-dependent signaling. Previous studies have identified three distinct receptor binding sites, I, II, and III, crucial for the binding of murine IL-11 (mIL-11) to both the IL-11R and gp130. In this study, we have further characterized the role of the mIL-11 site III mutant W147A. We show that W147A is a high-affinity specific antagonist of mIL-11-mediated signaling in gp130/IL-11R-transfected Ba/F3 cells. The antagonistic action of W147A is due to its ability to competitively disrupt multimeric gp130/IL-11R signaling complex formation. We also show that W147A inhibits IL-11-mediated signaling in primary human endometrial cells, thus demonstrating the potential utility of W147A in suppressing IL-11 responses in vivo.
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Key Words
- gst, glutathione-s-transferase
- hil, hil, recombinant human il
- hlif, human lif
- il-11r, il-11-specific receptor
- lif, leukemia inhibitory factor
- mil, murine il
- mlifr, murine lif receptor
- mtt, 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide
- sds, sodium dodecyl sulfate
- stat, signal transducer and activator of transcription
- vil, viral il
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Affiliation(s)
- Nicholas Underhill-Day
- Cancer Research UK Growth Factor Group, School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom.
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Sofi M, Young MJ, Papamakarios T, Simpson ER, Clyne CD. Role of CRE-binding protein (CREB) in aromatase expression in breast adipose. Breast Cancer Res Treat 2003; 79:399-407. [PMID: 12846424 DOI: 10.1023/a:1024038632570] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Estrogen biosynthesis from C19 steroids is catalyzed by aromatase cytochrome P450. Aromatase is expressed in breast adipose tissue through the use of a distal, cytokine-responsive promoter (promoter I.4). Breast tumors, however, secrete soluble factors that over-stimulate aromatase expression through an alternative proximal cAMP-responsive promoter, promoter II. We have mapped the cAMP-responsive regions of promoter II by transient transfection of 3T3-L1 preadipocytes with aromatase promoter II reporter genes. 5' deletion and mutation analyses identified two cAMP response element (CRE)-like sequences (CRE1 and CRE2) that were essential for cAMP-induced promoter II activity. Electrophoretic mobility shift analysis demonstrated that CRE binding protein (CREB) bound to each element, and that this interaction was enhanced in the presence of cAMP. Quantification of CREB mRNA expression in adipose tissue from normal and tumor bearing breast adipose tissue revealed that CREB expression is approximately five times higher in tumor bearing than in normal breast adipose tissue. Thus, the over expression of aromatase in adipose tissue surrounding breast tumors could arise through increases in both CREB expression and CREB transcriptional activity. Pharmacological inhibition of CREB activity, previously shown to have anti-proliferative effects on cancer cells, might therefore have additional benefits through inhibition of aromatase expression and thus estrogen production in breast adipose.
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Affiliation(s)
- Mariam Sofi
- Prince Henry's Institute of Medical Research, Clayton, VC, Australia
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