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Kilcar AY, Biber Muftuler FZ, Unak P, Avci CB, Gunduz C. Diethylenetriamine Pentaacetic Acid Derivative of Toremifene and In Vitro Evaluation in Human Breast Cancer Cell Line MCF-7. Cancer Biother Radiopharm 2011; 26:105-11. [DOI: 10.1089/cbr.2010.0860] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Ayfer Yurt Kilcar
- Department of Nuclear Applications, Institute of Nuclear Sciences, Ege University, Izmir, Turkey
| | - F. Zumrut Biber Muftuler
- Department of Nuclear Applications, Institute of Nuclear Sciences, Ege University, Izmir, Turkey
| | - Perihan Unak
- Department of Nuclear Applications, Institute of Nuclear Sciences, Ege University, Izmir, Turkey
| | - Cigir Biray Avci
- Department of Medical Biology, Faculty of Medicine, Ege University, Izmir, Turkey
| | - Cumhur Gunduz
- Department of Medical Biology, Faculty of Medicine, Ege University, Izmir, Turkey
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2
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Yurt A, Muftuler FZB, Unak P, Yolcular S, Acar C, Enginar H. Synthesis of a novel antiestrogen radioligand (99mTc-TOR-DTPA). Cancer Biother Radiopharm 2010; 24:707-16. [PMID: 20025551 DOI: 10.1089/cbr.2009.0656] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
This study was aimed at developing a hydrophilic radioligand as an antiestrogen drug derivative to be used for imaging breast tumors. Toremifene [TOR; 4-chloro-1,2-diphenyl-1-(4-(2-(N,N-di-methylamino)ethoxy)phenyl)-1-butene, as citrate salt] was selected as the starting material to be derived, since it has been used extensively as an antiestrogen drug for treatment and prevention of human breast cancer. An antiestrogen drug derivative, TOR attached to diethylenetriamine pentaacetic acid (DTPA), was synthesized by two experimental treatments, including a purification and a reaction step. We described the synthesis of this TOR derivative, (3Z)-4-{4-[2-(dimethylamino) ethoxy] phenyl}-3,4-diphenylbut-3-en-1-ylN,N-bis[2-(2,6-dioxomorpholin-4-yl)ethyl]glycinate (TOR-DTPA), in detail. Mass spectroscopy confirmed the expected structures. TOR-DTPA was labeled with technetium-99m ((99m)Tc), using stannous chloride (SnCl(2)) as the reducing agent. Biodistribution studies were performed on female Albino Wistar rats. Quality controls, radiochemical yield, and stability studies were done utilizing high-performance liquid chromatography, radioelectrophoresis, thin-layer chromatography, and thin-layer radiochromatography methods. The synthesized compound was found to be hydrophilic and anionic, with high stability for the duration of the testing period in vitro. The results indicated that the radiolabeled compound has estrogen-receptor specificity, especially for the breast tissue. It is highly possible that this compound could be used for imaging breast tumors as a novel technetium-labeled hydrophilic estrogen derivative radioligand.
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Affiliation(s)
- Ayfer Yurt
- Department of Nuclear Applications, Institute of Nuclear Science, Ege University, Bornova, Izmir, Turkey
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3
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Chao EYH, Collins JL, Gaillard S, Miller AB, Wang L, Orband-Miller LA, Nolte RT, McDonnell DP, Willson TM, Zuercher WJ. Structure-guided synthesis of tamoxifen analogs with improved selectivity for the orphan ERRγ. Bioorg Med Chem Lett 2006; 16:821-4. [PMID: 16307879 DOI: 10.1016/j.bmcl.2005.11.030] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2005] [Revised: 11/05/2005] [Accepted: 11/07/2005] [Indexed: 10/25/2022]
Abstract
The design and synthesis of 4-hydroxytamoxifen (4-OHT) derivatives are described. The binding affinities of these compounds toward the orphan estrogen-related receptor gamma and the classical estrogen receptor alpha demonstrate that analogs bearing hydroxyalkyl groups display improved binding selectivity profiles compared with that of 4-OHT. An X-ray crystal structure of one of the designed compounds bound to ERRgamma LBD confirms the molecular basis of the selectivity.
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Affiliation(s)
- Esther Y H Chao
- Discovery Research, GlaxoSmithKline, Five Moore Drive, Research Triangle Park, NC 27709, USA
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4
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Curtis MG. Comparative tolerability of first-generation selective estrogen receptor modulators in breast cancer treatment and prevention. Drug Saf 2002; 24:1039-53. [PMID: 11735660 DOI: 10.2165/00002018-200124140-00003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In general, the selective estrogen receptor modulators (SERMs) currently indicated for the treatment and prevention of breast cancer, i.e. tamoxifen and toremifene, are fairly well tolerated. However, tamoxifen has been shown to induce hepatocellular carcinomas in rats, but not in humans, and can increase the risk of endometrial cancer in humans by two to three times. Other potentially serious adverse effects which have been associated with tamoxifen and toremifene therapy include vasomotor symptoms, an increased risk of venous thromboembolic events, and an increased incidence of cataracts and ocular toxicity, fatty liver, and nonmalignant hepatic and uterine changes. In addition, long term tamoxifen use almost always results in resistance to the drug and, indeed, has actually been shown to promote tumour proliferation in human breast cancer cells. Both tamoxifen and toremifene display drug interactions with a variety of drug classes. The adverse events associated with these compounds have raised significant concerns regarding their widespread use for the treatment and prevention of breast cancer. In addition, because of the weakness and scarcity of the data on toremifene, any conclusions about its tolerability remain tentative until outcomes of ongoing clinical trials in the adjuvant setting are known. A third SERM, raloxifene, is the focus of several large randomised trials examining its efficacy in the prevention of breast cancer. At present, each potential adverse event needs to be weighed against potential benefits in the decision to undergo SERM treatment. An array of therapies is currently available for patients with breast cancer and women at increased risk of disease; the risk-to-benefit ratio for each agent should be carefully examined in determining the most advantageous regimen.
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Affiliation(s)
- M G Curtis
- Department of Obstetrics/Gynecology, University of Texas at Houston, Houston, Texas 77026, USA.
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5
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Krishnan V, Heath H, Bryant HU. Mechanism of action of estrogens and selective estrogen receptor modulators. VITAMINS AND HORMONES 2001; 60:123-47. [PMID: 11037623 DOI: 10.1016/s0083-6729(00)60018-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Estrogen, one of several sex steroid hormones, mediates its actions through the estrogen receptor. The estrogen receptor (ER) has two subtypes, ER alpha and ER beta, each of which predominates in specific tissues and organs. Cofactor proteins interact with the ER to maximize ligand-dependent transactivation of target-gene promoters. The estrogen response element is the final step in estrogen-mediated gene regulation, and current research is focused on alternate response elements. The resulting biologic action can vary according to the specific type of ER, cofactor milieu, response element, and ligand. Selective estrogen receptor modulators (SERMs) exhibit tissue-specific estrogen agonist or antagonist activity. The SERM raloxifene, which binds to ER and targets a distinct DNA element, may distinguish agonist vs antagonist activity by ER subtype and has unique activity among other SERMs because of its molecular conformation. Phytoestrogens, a potential alternative to hormone replacement therapy and for cancer prevention, do not consistently mimic estrogen's activity. Different types of phytoestrogens have different potencies, and taking high-dose supplements after menopause may not emulate the apparent benefits of lifelong consumption of phytoestrogen-rich diets. In conclusion, the complexity of estrogen action--through different ER subtypes, with various cofactors, on alternate response element--is further enhanced by ligands with selective estrogen activity. Additional research is needed to elucidate these pathways and the resulting biological effects.
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Affiliation(s)
- V Krishnan
- Lilly Research Laboratories, Indianapolis, Indiana 46285, USA
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6
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Nuwaysir EF, Dragan YP, McCague R, Martin P, Mann J, Jordan VC, Pitot HC. Structure-activity relationships for triphenylethylene antiestrogens on hepatic phase-I and phase-II enzyme expression. Biochem Pharmacol 1998; 56:321-7. [PMID: 9744569 DOI: 10.1016/s0006-2952(98)00156-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
To better understand the mechanism(s) by which tamoxifen induces rat hepatic CYPIIB2 and suppresses GSTA1, structure-activity studies were performed. Compounds employed in these studies included: tamoxifen, fixed-ring tamoxifen, ethylated fixed-ring tamoxifen, pyrrolidino-tamoxifen, 4-iodotamoxifen, idoxifene, and toremifene. With respect to GSTA1 suppression, tamoxifen, fixed-ring tamoxifen, 4-iodotamoxifen, idoxifene, and toremifene were all potent suppressors of GSTA1, while ethylated fixed-ring tamoxifen and pyrrolidino-tamoxifen were completely without activity. The results suggest that the aminoethoxy side chain plays a crucial role in GSTA1 suppression, and that 4-iodination may potentiate this activity. With respect to induction of CYPIIB2, tamoxifen, fixed-ring tamoxifen, and ethylated fixed-ring tamoxifen were inducers of this enzyme, while toremifene and 4-iodotamoxifen were inactive, suggesting that the aminoethoxy side chain is not a structural determinant of CYPIIB2 induction. Because ethylated fixed-ring tamoxifen, toremifene, and 4-iodotamoxifen had differential activities in the two assays, we conclude that CYPIIB2 induction and GSTA1 suppression by triphenylethylenes are the result of two separate and distinct mechanistic pathways. Structure-activity relationships for GSTA1 suppression and CYPIIB2 induction were compared with previously published relationships for triphenylethylene: 1) estrogen receptor relative binding affinity; 2) calmodulin antagonism; 3) antiuterotrophic activity; and 4) antagonism of MCF-7 cell growth. No clear correlation was observed between the effects on CYPIIB2 and these other four activities, suggesting no relationship between the mechanisms responsible for these effects. Similarly, no precise correlation was observed between GSTA1 suppression and these other activities, although rough similarities were observed for relative binding affinity and antiuterotrophic activity. This suggests that the mechanisms responsible for CYPIIB2 induction and GSTA1 suppression are not related to the mechanisms of action for these other documented activities, and may represent different mechanistic pathways.
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Affiliation(s)
- E F Nuwaysir
- Environmental Toxicology Center, University of Wisconsin, Madison, USA
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7
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Rickard SE, Thompson LU. Chronic exposure to secoisolariciresinol diglycoside alters lignan disposition in rats. J Nutr 1998; 128:615-23. [PMID: 9482772 DOI: 10.1093/jn/128.3.615] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Mammalian lignans from colonic bacterial action on secoisolariciresinol diglycoside (SDG) may mediate the anticarcinogenic effect of prolonged SDG feeding in rats. To elucidate lignan bioactivity, our objective was to determine 3H-SDG disposition in rats with acute or chronic SDG treatment over 48 h. After food deprivation overnight, female Sprague-Dawley rats (70-72 d old) were given a single gavage of 3H-SDG (3.7 kBq/g body weight) either immediately (acute, n = 12) or after 10 d of gavage with 1.5 mg unlabeled SDG/d (chronic, n = 12). Rats were killed at 12, 24, 36 and 48 h after gavage, and samples collected and analyzed for radioactivity by liquid scintillation counting. Radioactivity was 1- to 16-fold higher at 12 vs. 48 h for tissues, blood and gastrointestinal contents (P < 0.05). By 48 h, >80% of the recovered dose was excreted in both groups (feces > 50%, urine = 28-32%). Tissue radioactivity was highest (by 0.5- to 176-fold) in the cecum (P < 0.05). Levels in the liver, kidney and uterus (12 h) were 0.2- to 7.5-fold higher than in other nongastrointestinal tissues. At 12 h, fecal radioactivity was negligible, and cecal content, liver and adipose radioactivity were one- to threefold greater in rats with chronic SDG exposure than in those acutely exposed (P < 0.05). Blood radioactivity, present mostly in the plasma fraction (0.4% of dose), suggested that lignan concentrations could be 3000 times higher than peak estrogen levels in rats. Thus, SDG metabolites accumulated in the liver, kidney, intestinal tissues and uterus. Chronic SDG exposure delayed fecal excretion while increasing liver and adipose lignan levels.
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Affiliation(s)
- S E Rickard
- Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada M5S 3E2
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8
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Gauthier S, Mailhot J, Labrie F. New Highly Stereoselective Synthesis of (Z)-4-Hydroxytamoxifen and (Z)-4-Hydroxytoremifene via McMurry Reaction. J Org Chem 1996; 61:3890-3893. [PMID: 11667248 DOI: 10.1021/jo952279l] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sylvain Gauthier
- Medicinal Chemistry Division, Laboratory of Molecular Endocrinology, CHUL Research Centre, Québec City, Québec G1V 4G2, Canada
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9
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Abstract
Endocrine treatment plays an important role in the therapy of breast cancer. While the basic mechanisms are understood, additional mechanisms may be of importance to their action and they may also contribute to the mechanism(s) of acquired resistance. Currently, several novel drugs are entering into clinical trials. Observations of the absence or presence of cross resistance to novel 'pure' steroidal antiestrogens and the non-steroidal tamoxifen may add important information to our understanding of the mechanisms of action of both classes of drugs. Similarly, exploration of different aromatase inhibitors in sequence or concert, as well as the combining of different endocrine treatment options may be warranted. Additionally, alterations in different biochemical parameters such as growth factors should not only be carefully explored in relation to treatment options but should also be followed during the course of treatment to asess alterations over time and in relation to the development of drug resistance.
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MESH Headings
- Adrenal Cortex/drug effects
- Adrenal Cortex/physiopathology
- Adult
- Aged
- Animals
- Antineoplastic Agents, Hormonal/classification
- Antineoplastic Agents, Hormonal/pharmacology
- Antineoplastic Agents, Hormonal/therapeutic use
- Aromatase Inhibitors
- Breast Neoplasms/drug therapy
- Breast Neoplasms/genetics
- Breast Neoplasms/physiopathology
- Breast Neoplasms/therapy
- Chemotherapy, Adjuvant
- Combined Modality Therapy
- Drug Resistance, Multiple
- Enzyme Inhibitors/pharmacology
- Enzyme Inhibitors/therapeutic use
- Estrogen Antagonists/adverse effects
- Estrogen Antagonists/pharmacology
- Estrogen Antagonists/therapeutic use
- Estrogens/blood
- Estrogens/physiology
- Female
- Gene Expression Regulation, Neoplastic/drug effects
- Gonadotropin-Releasing Hormone/agonists
- Humans
- Insulin-Like Growth Factor I/antagonists & inhibitors
- Insulin-Like Growth Factor I/physiology
- Mammary Neoplasms, Experimental/drug therapy
- Mammary Neoplasms, Experimental/physiopathology
- Menopause
- Mice
- Middle Aged
- Neoplasm Proteins/antagonists & inhibitors
- Neoplasms, Hormone-Dependent/drug therapy
- Neoplasms, Hormone-Dependent/genetics
- Neoplasms, Hormone-Dependent/physiopathology
- Neoplasms, Hormone-Dependent/therapy
- Progesterone/antagonists & inhibitors
- Progesterone/physiology
- Progestins/antagonists & inhibitors
- Progestins/pharmacology
- Progestins/therapeutic use
- Receptors, Estrogen/drug effects
- Receptors, Estrogen/physiology
- Signal Transduction/drug effects
- Steroids/metabolism
- Tamoxifen/adverse effects
- Tamoxifen/pharmacology
- Tamoxifen/therapeutic use
- Tumor Cells, Cultured/drug effects
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Affiliation(s)
- E Lønning
- Department of Oncology, Haukeland University Hospital, Bergen, Norway
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10
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Wilson S, Ruenitz PC, Ruzicka JA. Estrogen receptor affinity and effects on MCF-7 cell growth of triarylethylene carboxylic acids related to tamoxifen. J Steroid Biochem Mol Biol 1992; 42:613-6. [PMID: 1637724 DOI: 10.1016/0960-0760(92)90452-o] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The estrogen receptor binding, and growth suppressant and stimulating effects in MCF-7 human breast cancer cells, of four structural variants of the triarylethylene antiestrogen tamoxifen (1) were studied. In these analogs, the dialkylaminoethoxy side chain of 1 was replaced by carboxylic acid or oxyacetic acid substituents. The presence of a p-hydroxy group in the ring geminal to the one bearing the side chain resulted in ligands with estrogen receptor affinities greater than that of 1 but less than that of estradiol. Compared to 1, none of the test compounds were effective suppressants of cell growth. To the contrary, the phenolic oxyacetic acid analog effectively reversed the growth suppressive effect of 1. Also, it was as effective as estradiol, though less potent, in stimulating growth of cells grown in estrogen depleted medium, suggestive of full estrogen agonist activity. Its carboxylic acid counterpart had little or no effect on proliferation. Because the phenolic oxyacetic acid is a metabolite of 1 in animals, its estrogenicity may have therapeutic implications of concern, depending on the extent to which it is formed and distributed in tissues of patients receiving 1.
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Affiliation(s)
- S Wilson
- College of Pharmacy, University of Georgia, Athens 30602
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11
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Di Lorenzo D, Ruggeri G, Iacobello C, Belloli S, Gion M, Zava DT, Ghielmi S, Albertini A. Evaluation of a Radioreceptor Assay to Assess Exogenous Estrogen Activity in Serum of Patients with Breast Cancer. Int J Biol Markers 1991; 6:151-8. [PMID: 1791309 DOI: 10.1177/172460089100600303] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A radioreceptor assay (RRA) for the determination of total estrogen activity, was set up and used to assess the possible presence of exogenous molecules with estrogen activity in serum; a comparison was made with the specific radioimmunoassay (RIA) for the endogenous estrogen 17-B estradiol (17-B-E2). The assay was first performed on sera from healthy people taking estrogens in the form of oral contraceptives or lotions for local application whose total estrogenic activity in the blood was assumed to be abnormal. The assay was then performed on serum from 98 patients with early breast cancer and 20 patients with metastasis, not undergoing hormone therapy. A higher estrogen activity was found in 2.5% of sera compared to the activity found using the RIA method which is specific for endogenous estrogen 17-B-E2, the RRA/17-B-E2 ratio being higher than 3. Increased estrogen activity was found in 10% serum samples from digoxin treated cardiopathic patients, with an RRA/17-B-E2 ratio ranging from 4.4 to 20. The RRA assay could prove useful for showing up exogenous estrogen activity from various sources (drugs, food) in sera of people in whom estrogen stimulation could be potentially dangerous (i.e. in patients with hormone-sensitive tumors). This exogenous activity could support a certain degree of neoplastic stimulation and, therefore, unfavourably condition the patients’ therapeutic response.
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Affiliation(s)
- D Di Lorenzo
- Cattedra di Chimica e Propedeutica Biochimica, Facoltà di Medicina e Chirurgia, Università di Brescia, Italy
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