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Remines M, Schoonover MG, Knox Z, Kenwright K, Hoffert KM, Coric A, Mead J, Ampfer J, Seye S, Strome ED. Profiling the compendium of changes in Saccharomyces cerevisiae due to mutations that alter availability of the main methyl donor S-Adenosylmethionine. G3 (BETHESDA, MD.) 2024; 14:jkae002. [PMID: 38184845 PMCID: PMC10989883 DOI: 10.1093/g3journal/jkae002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 11/17/2023] [Accepted: 12/16/2023] [Indexed: 01/09/2024]
Abstract
The SAM1 and SAM2 genes encode for S-Adenosylmethionine (AdoMet) synthetase enzymes, with AdoMet serving as the main cellular methyl donor. We have previously shown that independent deletion of these genes alters chromosome stability and AdoMet concentrations in opposite ways in Saccharomyces cerevisiae. To characterize other changes occurring in these mutants, we grew wildtype, sam1Δ/sam1Δ, and sam2Δ/sam2Δ strains in 15 different Phenotypic Microarray plates with different components and measured growth variations. RNA-Sequencing was also carried out on these strains and differential gene expression determined for each mutant. We explored how the phenotypic growth differences are linked to the altered gene expression, and hypothesize mechanisms by which loss of the SAM genes and subsequent AdoMet level changes, impact pathways and processes. We present 6 stories, discussing changes in sensitivity or resistance to azoles, cisplatin, oxidative stress, arginine biosynthesis perturbations, DNA synthesis inhibitors, and tamoxifen, to demonstrate the power of this novel methodology to broadly profile changes due to gene mutations. The large number of conditions that result in altered growth, as well as the large number of differentially expressed genes with wide-ranging functionality, speaks to the broad array of impacts that altering methyl donor abundance can impart. Our findings demonstrate that some cellular changes are directly related to AdoMet-dependent methyltransferases and AdoMet availability, some are directly linked to the methyl cycle and its role in production of several important cellular components, and others reveal impacts of SAM gene mutations on previously unconnected pathways.
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Affiliation(s)
- McKayla Remines
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY 41099, USA
| | - Makailyn G Schoonover
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY 41099, USA
| | - Zoey Knox
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY 41099, USA
| | - Kailee Kenwright
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY 41099, USA
| | - Kellyn M Hoffert
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY 41099, USA
| | - Amila Coric
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY 41099, USA
| | - James Mead
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY 41099, USA
| | - Joseph Ampfer
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY 41099, USA
| | - Serigne Seye
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY 41099, USA
| | - Erin D Strome
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY 41099, USA
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2
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Remines M, Schoonover M, Knox Z, Kenwright K, Hoffert KM, Coric A, Mead J, Ampfer J, Seye S, Strome ED. Profiling The Compendium Of Changes In Saccharomyces cerevisiae Due To Mutations That Alter Availability Of The Main Methyl Donor S-Adenosylmethionine. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.09.544294. [PMID: 37333147 PMCID: PMC10274911 DOI: 10.1101/2023.06.09.544294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
The SAM1 and SAM2 genes encode for S-AdenosylMethionine (AdoMet) synthetase enzymes, with AdoMet serving as the main methyl donor. We have previously shown that independent deletion of these genes alters chromosome stability and AdoMet concentrations in opposite ways in S. cerevisiae. To characterize other changes occurring in these mutants, we grew wildtype, sam1∆/sam1∆, and sam2∆/sam2∆ strains in 15 different Phenotypic Microarray plates with different components, equal to 1440 wells, and measured for growth variations. RNA-Sequencing was also carried out on these strains and differential gene expression determined for each mutant. In this study, we explore how the phenotypic growth differences are linked to the altered gene expression, and thereby predict the mechanisms by which loss of the SAM genes and subsequent AdoMet level changes, impact S. cerevisiae pathways and processes. We present six stories, discussing changes in sensitivity or resistance to azoles, cisplatin, oxidative stress, arginine biosynthesis perturbations, DNA synthesis inhibitors, and tamoxifen, to demonstrate the power of this novel methodology to broadly profile changes due to gene mutations. The large number of conditions that result in altered growth, as well as the large number of differentially expressed genes with wide-ranging functionality, speaks to the broad array of impacts that altering methyl donor abundance can impart, even when the conditions tested were not specifically selected as targeting known methyl involving pathways. Our findings demonstrate that some cellular changes are directly related to AdoMet-dependent methyltransferases and AdoMet availability, some are directly linked to the methyl cycle and its role is production of several important cellular components, and others reveal impacts of SAM gene mutations on previously unconnected pathways.
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Affiliation(s)
- McKayla Remines
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY 41099
| | - Makailyn Schoonover
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY 41099
| | - Zoey Knox
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY 41099
| | - Kailee Kenwright
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY 41099
| | - Kellyn M. Hoffert
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY 41099
| | - Amila Coric
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY 41099
| | - James Mead
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY 41099
| | - Joseph Ampfer
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY 41099
| | - Serigne Seye
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY 41099
| | - Erin D. Strome
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY 41099
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Lee S, Nam M, Lee AR, Baek ST, Kim MJ, Kim JS, Kong AH, Lee M, Lee SJ, Kim SY, Kim DU, Hoe KL. Genetic alterations in Wnt family of genes and their putative association with head and neck squamous cell carcinoma. Genomics Inform 2021; 19:e39. [PMID: 35172472 PMCID: PMC8752990 DOI: 10.5808/gi.21049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 10/15/2021] [Indexed: 11/24/2022] Open
Abstract
Tamoxifen (TAM) is an anticancer drug used to treat estrogen receptor (ER)‒positive breast cancer. However, its ER-independent cytotoxic and antifungal activities have prompted debates on its mechanism of action. To achieve a better understanding of the ER-independent antifungal action mechanisms of TAM, we systematically identified TAM-sensitive genes through microarray screening of the heterozygous gene deletion library in fission yeast (Schizosaccharomyces pombe). Secondary confirmation was followed by a spotting assay, finally yielding 13 TAM-sensitive genes under the drug-induced haploinsufficient condition. For these 13 TAM-sensitive genes, we conducted a comparative analysis of their Gene Ontology (GO) ‘biological process’ terms identified from other genome-wide screenings of the budding yeast deletion library and the MCF7 breast cancer cell line. Several TAM-sensitive genes overlapped between the yeast strains and MCF7 in GO terms including ‘cell cycle’ (cdc2, rik1, pas1, and leo1), ‘signaling’ (sck2, oga1, and cki3), and ‘vesicle-mediated transport’ (SPCC126.08c, vps54, sec72, and tvp15), suggesting their roles in the ER-independent cytotoxic effects of TAM. We recently reported that the cki3 gene with the ‘signaling’ GO term was related to the ER-independent antifungal action mechanisms of TAM in yeast. In this study, we report that haploinsufficiency of the essential vps54 gene, which encodes the GARP complex subunit, significantly aggravated TAM sensitivity and led to an enlarged vesicle structure in comparison with the SP286 control strain. These results strongly suggest that the vesicle-mediated transport process might be another action mechanism of the ER-independent antifungal or cytotoxic effects of TAM.
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Affiliation(s)
- Sol Lee
- Department of New Drug Development, Chungnam National University, Daejeon 34134, Korea
| | - Miyoung Nam
- Department of New Drug Development, Chungnam National University, Daejeon 34134, Korea
| | - Ah-Reum Lee
- Department of New Drug Development, Chungnam National University, Daejeon 34134, Korea
| | - Seung-Tae Baek
- Department of New Drug Development, Chungnam National University, Daejeon 34134, Korea
| | - Min Jung Kim
- Department of New Drug Development, Chungnam National University, Daejeon 34134, Korea
| | - Ju Seong Kim
- Department of New Drug Development, Chungnam National University, Daejeon 34134, Korea
| | - Andrew Hyunsoo Kong
- Morrissey College of Arts and Sciences, Boston College, Boston 02467, MA, USA
| | - Minho Lee
- Department of Life Science, Dongguk University-Seoul, Goyang 10326, Korea
| | - Sook-Jeong Lee
- Department of Bioactive Material Science, Jeonbuk National University, Jeonju 54896, Korea
| | - Seon-Young Kim
- Personalized Medicine Research Center, Korea Research Institute of Bioscience & Biotechnology (KRIBB), Daejeon 34141, Korea
| | - Dong-Uk Kim
- Rare Disease Research Center, Korea Research Institute of Bioscience & Biotechnology (KRIBB), Daejeon 34141, Korea
| | - Kwang-Lae Hoe
- Department of New Drug Development, Chungnam National University, Daejeon 34134, Korea.,Korea Research Institute of Chemistry & Technology, Daejeon 34141, Korea
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4
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Farha MA, Brown ED. Drug repurposing for antimicrobial discovery. Nat Microbiol 2019; 4:565-577. [PMID: 30833727 DOI: 10.1038/s41564-019-0357-1] [Citation(s) in RCA: 181] [Impact Index Per Article: 36.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 01/03/2019] [Indexed: 12/17/2022]
Abstract
Antimicrobial resistance continues to be a public threat on a global scale. The ongoing need to develop new antimicrobial drugs that are effective against multi-drug-resistant pathogens has spurred the research community to invest in various drug discovery strategies, one of which is drug repurposing-the process of finding new uses for existing drugs. While still nascent in the antimicrobial field, the approach is gaining traction in both the public and private sector. While the approach has particular promise in fast-tracking compounds into clinical studies, it nevertheless has substantial obstacles to success. This Review covers the art of repurposing existing drugs for antimicrobial purposes. We discuss enabling screening platforms for antimicrobial discovery and present encouraging findings of novel antimicrobial therapeutic strategies. Also covered are general advantages of repurposing over de novo drug development and challenges of the strategy, including scientific, intellectual property and regulatory issues.
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Affiliation(s)
- Maya A Farha
- Michael G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Eric D Brown
- Michael G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada.
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Shagufta, Ahmad I. Tamoxifen a pioneering drug: An update on the therapeutic potential of tamoxifen derivatives. Eur J Med Chem 2018; 143:515-531. [DOI: 10.1016/j.ejmech.2017.11.056] [Citation(s) in RCA: 99] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 10/25/2017] [Accepted: 11/20/2017] [Indexed: 12/13/2022]
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Cytoplasmic PELP1 and ERRgamma protect human mammary epithelial cells from Tam-induced cell death. PLoS One 2015; 10:e0121206. [PMID: 25789479 PMCID: PMC4366195 DOI: 10.1371/journal.pone.0121206] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 01/28/2015] [Indexed: 01/24/2023] Open
Abstract
Tamoxifen (Tam) is the only FDA-approved chemoprevention agent for pre-menopausal women at high risk for developing breast cancer. While Tam reduces a woman's risk of developing estrogen receptor positive (ER+) breast cancer, the molecular mechanisms associated with risk reduction are poorly understood. Prior studies have shown that cytoplasmic proline, glutamic acid and leucine rich protein 1 (PELP1) promotes Tam resistance in breast cancer cell lines. Herein, we tested for PELP1 localization in breast epithelial cells from women at high risk for developing breast cancer and found that PELP1 was localized to the cytoplasm in 36% of samples. In vitro, immortalized HMECs expressing a nuclear localization signal (NLS) mutant of PELP1 (PELP1-cyto) were resistant to Tam-induced death. Furthermore, PELP1-cyto signaling through estrogen-related receptor gamma (ERRγ) promoted cell survival in the presence of Tam. Overexpression of ERRγ in immortalized HMECs protected cells from Tam-induced death, while knockdown of ERRγ sensitized PELP1-cyto expressing HMECs to Tam. Moreover, Tam-induced HMEC cell death was independent of apoptosis and involved accumulation of the autophagy marker LC3-II. Expression of PELP1-cyto and ERRγ reduced Tam-induced LC3-II accumulation, and knockdown of ERRγ increased LC3-II levels in response to Tam. Additionally, PELP1-cyto expression led to the upregulation of MMP-3 and MAOB, known PELP1 and ERRγ target genes, respectively. Our data indicate that cytoplasmic PELP1 induces signaling pathways that converge on ERRγ to promote cell survival in the presence of Tam. These data suggest that PELP1 localization and/or ERRγ activation could be developed as tissue biomarkers for Tam responsiveness.
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7
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In vitro and in vivo effects of tamoxifen against larval stage Echinococcus granulosus. Antimicrob Agents Chemother 2014; 58:5146-54. [PMID: 24936598 DOI: 10.1128/aac.02113-13] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Cystic echinococcosis is a zoonotic infection caused by the larval stage of the cestode Echinococcus granulosus. Chemotherapy currently employs benzimidazoles; however, 40% of cases do not respond favorably. With regard to these difficulties, novel therapeutic tools are needed to optimize treatment in humans. The aim of this work was to explore the in vitro and in vivo effects of tamoxifen (TAM) against E. granulosus. In addition, possible mechanisms for the susceptibility of TAM are discussed in relation to calcium homeostasis, P-glycoprotein inhibition, and antagonist effects on a putative steroid receptor. After 24 h of treatment, TAM, at a low micromolar concentration range (10 to 50 μM), inhibited the survival of E. granulosus protoscoleces and metacestodes. Moreover, we demonstrated the chemotherapeutic and chemopreventive pharmacological effects of the drug. At a dose rate of 20 mg/kg of body weight, TAM induced protection against the infection in mice. In the clinical efficacy studies, a reduction in cyst weight was observed after the administration of 20 mg/kg in mice with cysts developed during 3 or 6 months, compared to that of those collected from control mice. Since the collateral effects of high TAM doses have been largely documented in clinical trials, the use of low doses of this drug as a short-term therapy may be a novel alternative approach for human cystic echinococcosis treatment.
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Arnedos M, Smith I. Progression of endocrine therapies for breast cancer: where are we headed? Expert Rev Anticancer Ther 2014; 7:1651-64. [DOI: 10.1586/14737140.7.11.1651] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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9
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Kowalczyk P, Kowalczyk MC, Junco JJ, Tolstykh O, Kinjo T, Truong H, Walaszek Z, Hanausek M, Slaga TJ. The possible separation of 12-O-tetradecanoylphorbol-13-acetate-induced skin inflammation and hyperplasia by compound A. Mol Carcinog 2012; 52:488-96. [PMID: 22351517 DOI: 10.1002/mc.21883] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 01/13/2012] [Accepted: 01/18/2012] [Indexed: 01/08/2023]
Abstract
Activated glucocorticoid receptor (GR) acts via two different mechanisms: transcriptional regulation that requires DNA-binding, and protein-protein interaction between GR and other transcription factors, such as nuclear factor kappa B (NF-κB) or activator protein 1 (AP-1). It has been postulated that many important effects of glucocorticoids, including their anti-inflammatory properties, depend on GR's transrepressive effects on NF-κB and AP-1. In the present study, we have employed a TPA-induced model of skin inflammation and epidermal hyperplasia to determine whether partial activation of the glucocorticoid receptor by compound A (CpdA) is sufficient to reverse the effect of TPA treatment. CpdA is a nonsteroidal GR modulator with high binding affinity, is capable of partial activation of GR. Topical application of TPA twice per week for 2 wk results in inflammation and epidermal hyperplasia. TPA treatment also elevates levels of c-jun (AP-1 component), cyclooxygenase-2 (COX-2), p50 (NF-κB component), interleukin-6 (IL-6), and tumor necrosis factor (TNF) in the skin. Fluocinolone acetonide (FA) (a full GR agonist) was able to completely reverse the above effects of TPA. When applied alone, CpdA increased the epidermal thickness and keratinocyte proliferation as well as levels of c-jun, COX-2, IL-6, and IFN-γ. However, CpdA treatment resulted in a decrease in the number of p50 positive cells induced by TPA, suggesting its role in inhibition of NF-κB. The level of metallothionein-1 mRNA, regulated by GR was also significantly decreased in skin samples treated with CpdA. Our results suggest that CpdA is able to inhibit GR transactivation and activate only some transrepression properties of GR.
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Affiliation(s)
- Piotr Kowalczyk
- Department of Pharmacology, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
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10
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Yun JW, Kim SK, Kim H. Prolonged protein turnover of glyceraldehyde-3-phosphate dehydrogenase by phospholipase C-gamma 1 is critical for anchorage-independent growth and ATP synthesis in transformed cells. Cancer Invest 2011; 29:93-101. [PMID: 21210726 DOI: 10.3109/07357907.2010.535062] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Overexpression of phospholipase C-γl (PLC-γl) in rat 3Y1 fibroblasts leads to the formation of tumors in nude mice. However, the molecular mechanism for PLC-γl-mediated cellular transformation has not been studied in detail. In this study, we found that glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a glycolytic enzyme, protein levels were increased substantially in cells overexpressing PLC-γl, and that PLC-γl upregulation of GAPDH was due to a decrease in ubiquitination, followed by sustained protein turnover and subsequent accumulation. These observations suggest that regulation of the turnover rate of GAPDH is critical for anchorage-independent growth and ATP synthesis of transformed cells.
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Affiliation(s)
- Jae Won Yun
- Department of Life Science, College of Natural Science, Daejin University, Pochen, Kyeonggido, Republic of Korea
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11
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Dolan K, Montgomery S, Buchheit B, Didone L, Wellington M, Krysan DJ. Antifungal activity of tamoxifen: in vitro and in vivo activities and mechanistic characterization. Antimicrob Agents Chemother 2009; 53:3337-46. [PMID: 19487443 PMCID: PMC2715577 DOI: 10.1128/aac.01564-08] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2008] [Revised: 01/28/2009] [Accepted: 05/25/2009] [Indexed: 11/20/2022] Open
Abstract
Tamoxifen (TAM), an estrogen receptor antagonist used primarily to treat breast cancer, has well-recognized antifungal properties, but the activity of TAM has not been fully characterized using standardized (i.e., CLSI) in vitro susceptibility testing, nor has it been demonstrated in an in vivo model of fungal infection. In addition, its mechanism of action remains to be clearly defined at the molecular level. Here, we report that TAM displays in vitro activity (MIC, 8 to 64 microg/ml) against pathogenic yeasts (Candida albicans, other Candida spp., and Cryptococcus neoformans). In vivo, 200 mg/kg of body weight per day TAM reduced kidney fungal burden (-1.5 log(10) CFU per g tissue; P = 0.008) in a murine model of disseminated candidiasis. TAM is a known inhibitor of mammalian calmodulin, and TAM-treated yeast show phenotypes consistent with decreased calmodulin function, including lysis, decreased new bud formation, disrupted actin polarization, and decreased germ tube formation. The overexpression of calmodulin suppresses TAM toxicity, hypofunctional calmodulin mutants are hypersensitive to TAM, and TAM interferes with the interaction between Myo2p and calmodulin, suggesting that TAM targets calmodulin as part of its mechanism of action. Taken together, these experiments indicate that the further study of compounds related to TAM as antifungal agents is warranted.
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Affiliation(s)
- Kristy Dolan
- Department of Pediatrics, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
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Baker JC, Ostrander JH, Lem S, Broadwater G, Bean GR, D'Amato NC, Goldenberg VK, Rowell C, Ibarra-Drendall C, Grant T, Pilie PG, Vasilatos SN, Troch MM, Scott V, Wilke LG, Paisie C, Rabiner SM, Torres-Hernandez A, Zalles CM, Seewaldt VL. ESR1 promoter hypermethylation does not predict atypia in RPFNA nor persistent atypia after 12 months tamoxifen chemoprevention. Cancer Epidemiol Biomarkers Prev 2008; 17:1884-90. [PMID: 18708376 DOI: 10.1158/1055-9965.epi-07-2696] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
PURPOSE Currently, we lack biomarkers to predict whether high-risk women with mammary atypia will respond to tamoxifen chemoprevention. EXPERIMENTAL DESIGN Thirty-four women with cytologic mammary atypia from the Duke University High-Risk clinic were offered tamoxifen chemoprevention. We tested whether ESR1 promoter hypermethylation and/or estrogen receptor (ER) protein expression by immunohistochemistry predicted persistent atypia in 18 women who were treated with tamoxifen for 12 months and in 16 untreated controls. RESULTS We observed a statistically significant decrease in the Masood score of women on tamoxifen chemoprevention for 12 months compared with control women. This was a significant interaction effect of time (0, 6, and 12 months) and treatment group (tamoxifen versus control) P = 0.0007. However, neither ESR1 promoter hypermethylation nor low ER expression predicted persistent atypia in Random Periareolar Fine Needle Aspiration after 12 months tamoxifen prevention. CONCLUSIONS Results from this single institution pilot study provide evidence that, unlike for invasive breast cancer, ESR1 promoter hypermethylation and/or low ER expression is not a reliable marker of tamoxifen-resistant atypia.
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Nasu K, Takai N, Nishida M, Narahara H. Tumorigenic effects of tamoxifen on the female genital tract. CLINICAL MEDICINE. PATHOLOGY 2008; 1:17-34. [PMID: 21876648 PMCID: PMC3160006 DOI: 10.4137/cpath.s487] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Tamoxifen is widely used for endocrine treatment and breast cancer prevention. It acts as both an estrogen antagonist in breast tissue and an estrogen agonist in the female lower genital tract. Tamoxifen causes severe gynecologic side effects, such as endometrial cancer. This review focuses on the effects of prolonged tamoxifen treatment on the human female genital tract and considers its tumorigenicity in the gynecologic organs through clinical data analysis. Tamoxifen is associated with an increased incidence of benign endometrial lesions such as polyps and hyperplasia and a two- to four-fold increased risk of endometrial cancer in postmenopausal patients. Moreover, the incidence of functional ovarian cysts is significantly high in premenopausal tamoxifen users. To prevent tamoxifen from having severe side effects in gynecologic organs, frequent gynecological examination should be performed for both premenopausal and postmenopausal patients with breast cancer who are treated with this drug.
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Affiliation(s)
- Kaei Nasu
- Department of Obstetrics and Gynecology, Faculty of Medicine, Oita University, Oita, Japan
| | - Noriyuki Takai
- Department of Obstetrics and Gynecology, Faculty of Medicine, Oita University, Oita, Japan
| | - Masakazu Nishida
- Department of Obstetrics and Gynecology, Faculty of Medicine, Oita University, Oita, Japan
| | - Hisashi Narahara
- Department of Obstetrics and Gynecology, Faculty of Medicine, Oita University, Oita, Japan
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14
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Saadat M, Truong PT, Kader HA, Speers CH, Berthelet E, McMurtrie E, Olivotto IA. Outcomes in patients with primary breast cancer and a subsequent diagnosis of endometrial cancer : comparison of cohorts treated with and without tamoxifen. Cancer 2007; 110:31-7. [PMID: 17510927 DOI: 10.1002/cncr.22734] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND The study compared tumor characteristics and survival in women with breast cancer who subsequently developed endometrial cancer with or without a history of tamoxifen use. METHODS The British Columbia Cancer Agency registry identified 163 women diagnosed with breast cancer between 1989-1999 who received a subsequent diagnosis of endometrial cancer. Of these, 55% (n = 90) had a history of tamoxifen use. Outcomes analyzed were breast cancer-specific survival (BCSS), endometrial cancer-specific survival (ECSS), and overall survival (OS). RESULTS Median follow-up was 9.4 years. Distributions of age, menopausal status, body mass index, and comorbidities were similar in the tamoxifen-treated and nontamoxifen cohorts. Proportions of aggressive endometrial cancer subtypes including papillary serous, clear cell, and mixed mullerian tumors were higher in the tamoxifen cohort (28% vs14%, P = .03). Distributions of endometrial cancer grade and stage were similar in the 2 groups (P > .05). Hysterectomy and/or oophorectomy were the primary treatments for endometrial cancer in 99% of patients, with comparable pelvic control rates in the tamoxifen and nontamoxifen groups. At 10 years, patients in the tamoxifen group experienced lower BCSS compared with the nontamoxifen group (89% vs 97%, P = .02). No significant differences in ECSS and OS were observed between the 2 groups (ECSS 82% and 82%, P = .85; and OS 69% v. 66%, P = .85). CONCLUSIONS In patients with breast cancer who developed a subsequent endometrial cancer, tamoxifen-treated patients had higher proportions of aggressive endometrial cancer subtypes, but almost all cases were amenable to surgery, thus resulting in similar endometrial cancer control and survival when compared with nontamoxifen treated patients.
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Affiliation(s)
- Mandana Saadat
- Radiation Therapy Program, British Columbia Cancer Agency, Vancouver Island Centre, University of British Columbia, British Columbia, Canada
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15
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Pendse SS, Behjati S, Schatton T, Izawa A, Sayegh MH, Frank MH. P-glycoprotein functions as a differentiation switch in antigen presenting cell maturation. Am J Transplant 2006; 6:2884-93. [PMID: 17083370 DOI: 10.1111/j.1600-6143.2006.01561.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
P-glycoprotein (P-gp) expressed on human antigen presenting cells (APC) regulates alloantigen-dependent T-cell activation, but the associated mechanisms are not well understood. Here we demonstrate that P-gp functions in IL-12-dependent monocyte differentiation into dendritic cell (DC) lineages during APC maturation, thereby regulating the capacity of myeloid-derived APCs to elicit alloimmune Th1 responses. Human CD14+ monocytes cultured in vitro in the presence of IL-4/GM-CSF differentiated into CD14(-) CD1A+ APCs of the immature DC phenotype. In contrast, P-gp blockade during differentiation inhibited CD1a induction, down-regulated CD80 expression, enhanced CD86 expression and induced CD68 expression. APCs differentiated in the presence of P-gp blockade stimulated alloimmune T-cell proliferation significantly less than controls and this effect was associated with 97% inhibition of Th1 IFN-gamma production, but preserved Th2 IL-5 secretion. MAb-mediated blockade of the P-gp transport substrate IL-12 in the course of APC differentiation also inhibited IFN-gamma production, while addition of rIL-12 to P-gp-blocked APC differentiation cultures significantly reversed this effect, demonstrating that P-gp functions in APC differentiation in part via IL-12 regulation. Our findings define a novel role for P-gp as a differentiation switch in APC maturation and resultant alloimmune Th1 responses, thereby identifying P-gp as a potential novel therapeutic target in allotransplantation.
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Affiliation(s)
- S S Pendse
- Transplantation Research Center, Children's Hospital Boston, Massachusetts, USA
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. ZM, . ME, . EA. Studying the Role of P-glycoprotein in Resistance to Tamoxifen in Humen Breast Cancer T47D Cells by Immunocytochemistry. INT J PHARMACOL 2005. [DOI: 10.3923/ijp.2005.112.117] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Ferrer-Lorente R, García-Peláez B, Fernández-López JA, Remesar X, Alemany M. Tamoxifen does not prevent the mobilization of body lipids elicited by oleoyl-estrone. Steroids 2004; 69:661-5. [PMID: 15465111 DOI: 10.1016/j.steroids.2004.06.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2004] [Revised: 06/01/2004] [Accepted: 06/06/2004] [Indexed: 01/11/2023]
Abstract
Oleoyl-estrone is a powerful, slimming adipose tissue-derived signal that has biological effects widely opposed to those of its estrone moiety. The present experiment was designed to determine whether oleoyl-estrone effects on body energy are mediated by the estrogen receptor, blocked with the antagonist tamoxifen. Male Wistar rats were given daily oral doses of 10 micromol/kg d of oleoyl-estrone in oil containing 0 or 0.40 mg/kg d of tamoxifen. The data were compared with controls receiving only oil or 50 nmol/kg d of free estrone. After 10 days, the rats were killed, and their body composition and plasma metabolites and hormones were analyzed. Rats receiving estrone increased their body energy and lipid content compared with controls. Both groups of oleoyl-estrone-treated rats lost body weight, energy, and lipid; the losses in the rats receiving tamoxifen alone were less marked than in those receiving oleoyl-estrone. No significant changes in plasma glucose or triacylglycerols were observed. The patterns of change of estrone sulphate, estradiol, and oleoyl-estrone were consistent with a noticeable hydrolysis of oleoyl-estrone. The lack of differences in the fat mass in oleoyl-estrone-treated rats irrespective of the presence of tamoxifen suggested that the estrogenic pathway was not responsible for the slimming effects observed. Thus, it can be concluded that oleoyl-estrone effects are not mediated through its conversion to estrone or estradiol acting through the estrogen receptor. Tamoxifen partly mimicked the slimming effects of oleoyl-estrone; this could be speculatively explained by tamoxifen acting through the oleoyl-estrone signalling pathway.
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Affiliation(s)
- Raquel Ferrer-Lorente
- Department of Nutrition and Food Science, Faculty of Biology, University of Barcelona. Av. Diagonal 645, 08028 Barcelona, Spain
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18
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Abstract
Tamoxifen is an effective and relatively non-toxic compound used in palliative and adjuvant treatment of breast cancer. More recently its preventive role in breast cancer has also been demonstrated. However, tamoxifen use is related to some increase in the risk of endometrial cancer and to a significant rise in the incidence of benign endometrial pathologies. The activity of tamoxifen against breast cancer is mainly achieved by blocking the oestrogen receptor, whereas the effect of this compound on the female genital tract is mostly related to its agonistic properties. Despite numerous studies no effective methods of tamoxifen-user surveillance have been developed and currently no active screening for endometrial cancer, apart from yearly gynaecological examination, is recommended in these patients. In other parts of the genital tract, tamoxifen increases the risk of some benign conditions and may cause difficulties in the interpretation of cervical smears. Further studies are warranted to develop more effective surveillance and methods decreasing the detrimental effects of tamoxifen on the female genital tract.
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Affiliation(s)
- Elzbieta Senkus-Konefka
- Department of Oncology and Radiotherapy, Medical University of Gdansk, Debinki 7, Gdansk 80-211, Poland.
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Wolff RA. Chemoprevention for pancreatic cancer. INTERNATIONAL JOURNAL OF GASTROINTESTINAL CANCER 2004; 33:27-41. [PMID: 12909736 DOI: 10.1385/ijgc:33:1:27] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
For a number of solid tumors, including pancreatic cancer, efforts aimed at disease prevention may be more successful than currently available anticancer treatments. While specific interventions are emerging to prevent breast, prostate, lung, and colorectal cancer, no trials of chemoprevention are being conducted in pancreatic cancer. Importantly, there are significant obstacles to the conduct of such research. However, preclinical and epidemiologic studies suggest that several drugs may have chemopreventive potential in pancreatic cancer. These include aspirin and other non-steroidal antiinflammatory drugs (NSAIDs), selective cyclooxygenase inhibitors, somatostatin analogs, selective estrogen receptor modulators (SERMs), and anti-androgenic agents. As the oncology community evaluates some of these agents in large chemoprevention trials for breast, colon, and prostate cancer, it may be found that pancreatic cancer prevention occurs as an unintended, but desirable consequence. Moreover, other general societal trends, such as smoking cessation and the widespread use of cholesterol-lowering agents and aspirin, could have a role in reducing the risk of pancreatic cancer, and in the future, may lead to a decrease in its incidence.
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Affiliation(s)
- Robert A Wolff
- The University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
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Tseng SH, Wang CH, Lin SM, Chen CK, Huang HY, Chen Y. Activation of c-Jun N-terminal kinase 1 and caspase 3 in the tamoxifen-induced apoptosis of rat glioma cells. J Cancer Res Clin Oncol 2004; 130:285-93. [PMID: 14997384 DOI: 10.1007/s00432-004-0546-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2003] [Accepted: 01/26/2004] [Indexed: 10/26/2022]
Abstract
PURPOSE The mechanisms of the antitumor effects of tamoxifen upon gliomas are still unclear. In this study, we investigated the role of c-Jun N-terminal kinase-1 (JNK1) and caspase 3 in the tamoxifen-induced apoptosis of rat glioma cells. METHODS Glioma cells were treated with tamoxifen, followed by a cytotoxicity assay to study its effects on the cells, and then a flow-activated cell sorter (FACS) analysis was performed to analyze the cellular apoptosis of the glioma cells. The expression of JNK1 and phospho-specific JNK1 in glioma cells treated with tamoxifen was investigated by Western blot analysis. The activity of caspase 3 in glioma cells was analyzed by caspase activity assay. RESULTS Tamoxifen was demonstrated to exert cytotoxic effects upon and induced apoptosis of the glioma cells in a concentration- and time-dependent manner (P<0.05). Western blot analysis demonstrated that tamoxifen increased the expression of phospho-specific JNK1 in glioma cells, and an increasing concentration of tamoxifen induced an increasing expression of phospho-specific JNK1. Four-hour 50-microM tamoxifen treatment increased the expression of phospho-specific JNK1 to 3.2 times that of the control level in glioma cells. Tamoxifen also increased the activity of caspase 3 in glioma cells. Pretreatment of glioma cells with the antisense oligonucleotide (OGN) of JNK1 immediately prior to tamoxifen treatment suppressed the expression of phospho-specific JNK1 and the activity of caspase 3. The apoptosis fraction of glioma cells induced by 4-h treatment with 50 microM tamoxifen was decreased from 51% to 28% by pretreatment with the antisense OGN of JNK1 (P<0.003), and to 20% by pretreatment with caspase 3 inhibitor (DEVD-CHO) (P<0.0008). CONCLUSIONS The results suggest that the tamoxifen-induced apoptosis of rat glioma cells is related to the activation of the JNK1/caspase 3 signaling pathway; however, the confirmation of the occurrence of such activation in vivo needs further investigation.
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Affiliation(s)
- Sheng-Hong Tseng
- Department of Surgery, National Taiwan University Hospital and National Taiwan University College of Medicine, 7 Chung-Shan S. Road, Taipei, Taiwan
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21
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Dietze EC, Troch MM, Bean GR, Heffner JB, Bowie ML, Rosenberg P, Ratliff B, Seewaldt VL. Tamoxifen and tamoxifen ethyl bromide induce apoptosis in acutely damaged mammary epithelial cells through modulation of AKT activity. Oncogene 2004; 23:3851-62. [PMID: 14990993 DOI: 10.1038/sj.onc.1207480] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Normal human mammary epithelial cells (HMECs), unlike estrogen receptor-positive (ER+) breast cancers, typically express low nuclear levels of ER (ER-'poor'). We previously demonstrated that 1.0 microM tamoxifen (Tam) induced apoptosis in ER-'poor' HMECs acutely transduced with human papillomavirus-16 E6 (HMEC-E6) through a rapid mitochondrial signaling pathway. Here, we show that plasma membrane-associated E2-binding sites initiate the rapid apoptotic effects of Tam in HMEC-E6 cells through modulation of AKT activity. At equimolar concentrations, Tam and tamoxifen ethyl bromide (QTam), a membrane impermeant analog of Tam, rapidly induced apoptosis in HMEC-E6 cells associated with an even more rapid decrease in phosphorylation of AKT at serine-473. Treatment of HMEC-E6 cells with 1.0 microM QTam resulted in a 50% decrease in mitochondrial transmembrane potential, sequential activation of caspase-9 and -3, and a 90% decrease in AKT Ser-473 phosphorylation. The effects of both Tam and QTam were blocked by expression of constitutively active AKT (myristoylated AKT or AKT-Thr308Asp/Ser473Asp). These data indicate that Tam and QTam induce apoptosis in HMEC-E6 cells through a plasma membrane-activated AKT-signaling pathway that results in (1) decreased AKT phosphorylation at Ser-473, (2) mitochondrial membrane depolarization, and (3) activated caspase-9 and -3.
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Affiliation(s)
- Eric C Dietze
- Division of Medical Oncology, Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
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22
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Kimelberg HK, Jin Y, Charniga C, Feustel PJ. Neuroprotective activity of tamoxifen in permanent focal ischemia. J Neurosurg 2003; 99:138-42. [PMID: 12854756 DOI: 10.3171/jns.2003.99.1.0138] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT The authors have previously shown that tamoxifen is effective in protecting brain tissue from ischemic injury in a rat model of reversible focal ischemia. In this study the authors tested whether similar protective effects are found in a rat model of permanent focal ischemia (permanent middle cerebral artery [MCA] occlusion). METHODS Tamoxifen (20 mg/kg) was given either before or at 1, 3, or 6 hours after permanent MCA occlusion in rats, with sustaining doses given every 12 hours thereafter. The median infarct volume measured after 72 hours was 113 mm3 for the vehicle (dimethyl sulfoxide) groups, compared with 31 mm3 for pretreatment, and 14, 27, and 98 mm3 for treatment beginning at 1, 3, and 6 hours, respectively, after permanent MCA occlusion. The infarct reductions in the pretreated and 1- and 3-hour post-MCA occlusion treatment groups were statistically significant (p < 0.05). At 3 hours after permanent MCA occlusion, tamoxifen also significantly reduced the infarct size at a lower dose of 5 mg/kg but not at 1 mg/kg; the same sustaining doses of 5 and 1 mg/kg were given every 12 hours. CONCLUSIONS Tamoxifen is as effective in a permanent model of focal ischemia as it is in the reversible model, and the therapeutic window of 3 hours after initiation of ischemia is identical. This effectiveness is likely due to several properties of the drug, including its known ability to cross the blood-brain barrier. Because tamoxifen has been administered safely in humans for treatment of gliomas at similarly high doses to those used in this study, it may be clinically useful as a treatment for ischemic stroke.
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Affiliation(s)
- Harold K Kimelberg
- Center for Neuropharmacology and Neuroscience, and Division of Neurosurgery, Albany Medical College, Albany, New York 12208, USA.
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23
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Salami S, Karami-Tehrani F. Biochemical studies of apoptosis induced by tamoxifen in estrogen receptor positive and negative breast cancer cell lines. Clin Biochem 2003; 36:247-53. [PMID: 12810152 DOI: 10.1016/s0009-9120(03)00007-9] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
OBJECTIVES Tamoxifen has been reported to show an efficacy in the treatment of breast cancer. Apoptosis could be a major mechanism of its antitumor effect. Therefore, this study has been designed to investigate the biochemical mechanisms of tamoxifen-induced apoptosis in both ER(+) MCF-7 and ER(-) MDA-MB468 breast cancer cell lines. METHODS Trypan blue dye exclusion test, Annexin V-Fluorescein/PI flow cytometry, MTT assay and Hoechst 33258 staining were used to detect cytotoxicity and apoptosis. The activation of caspase-3 was assayed by colorimetric assay kit. Bcl-2 and Bax proteins were estimated by western immunoblotting method. RESULTS Tamoxifen induced apoptosis in both cell lines (chi-square test, p < 0.05). Unlike the MCF-7 cells, which responded to the low concentration (1 microM), the treated MDA-MB468 cells have mainly been affected at a higher dose (20 microM) at which a significant increase was also obtained in the caspase-3 activity (chi-square test, p < 0.05). Interestingly, tamoxifen at doses higher than 2.5 microM increased cell proliferation in the MCF-7 cells. The levels of Bcl-2 and Bax remained unchanged. CONCLUSION Since tamoxifen has induced apoptosis in both cell lines by different mechanisms, it might be concluded that there exists ER(+) and ER(-) pathways for the induction of apoptosis.
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Affiliation(s)
- Siamak Salami
- Clinical Biochemistry Department, School of Medical Science, Tarbiat Modarres University, Tehran, Iran
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24
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Burow ME, Weldon CB, Tang Y, McLachlan JA, Beckman BS. Oestrogen-mediated suppression of tumour necrosis factor alpha-induced apoptosis in MCF-7 cells: subversion of Bcl-2 by anti-oestrogens. J Steroid Biochem Mol Biol 2001; 78:409-18. [PMID: 11738551 DOI: 10.1016/s0960-0760(01)00117-0] [Citation(s) in RCA: 31] [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: 11/21/2022]
Abstract
In oestrogen receptor (ER)-positive breast carcinoma cells, 17beta-oestradiol suppresses a dose-dependent induction of cell death by tumour necrosis factor alpha (TNF). The ability of oestrogens to promote cell survival in ER-positive breast carcinoma cells is linked to a coordinate increase in Bcl-2 expression, an effect that is blocked with the pure anti-oestrogen ICI 182,780. The role of Bcl-2 in MCF-7 cell survival was confirmed by stable overexpression of Bcl-2 which resulted in suppression of apoptosis induced by doxorubicin (DOX), paclitaxel (TAX) and TNF as compared to vector-control cells. The pure anti-oestrogen ICI 182,780 in combination with TNF, DOX or TAX potentiated apoptosis in vector-transfected cells. Interestingly, pre-treatment with ICI 182,780 markedly enhanced chemotherapeutic drug- or TNF-induced apoptosis in Bcl-2 expressing cells, an effect that was correlated with ICI 182,780 induced activation of c-Jun N-terminal kinase. Our results suggest that the effects of oestrogens/anti-oestrogens on the regulation of apoptosis may involve coordinate activation of signalling events and Bcl-2 expression.
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MESH Headings
- Antibiotics, Antineoplastic/administration & dosage
- Antibiotics, Antineoplastic/pharmacology
- Antineoplastic Agents, Phytogenic/administration & dosage
- Antineoplastic Agents, Phytogenic/pharmacology
- Apoptosis/drug effects
- Breast Neoplasms/drug therapy
- Breast Neoplasms/genetics
- Breast Neoplasms/metabolism
- Breast Neoplasms/pathology
- Cell Survival/drug effects
- Doxorubicin/administration & dosage
- Doxorubicin/pharmacology
- Drug Interactions
- Estradiol/administration & dosage
- Estradiol/analogs & derivatives
- Estradiol/pharmacology
- Estrogen Receptor Modulators/administration & dosage
- Estrogen Receptor Modulators/pharmacology
- Female
- Fulvestrant
- Genes, bcl-2
- Humans
- Mitogen-Activated Protein Kinases/metabolism
- Neoplasms, Hormone-Dependent/drug therapy
- Neoplasms, Hormone-Dependent/genetics
- Neoplasms, Hormone-Dependent/metabolism
- Neoplasms, Hormone-Dependent/pathology
- Paclitaxel/administration & dosage
- Paclitaxel/pharmacology
- Signal Transduction
- Transfection
- Tumor Cells, Cultured
- Tumor Necrosis Factor-alpha/administration & dosage
- Tumor Necrosis Factor-alpha/pharmacology
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Affiliation(s)
- M E Burow
- Center for Bioenvironmental Research, Tulane University Health Sciences Center, New Orleans, LA 70112, USA
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25
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Karami-Tehrani F, Salami S, Mokarram P. Competition of tamoxifen with thyroxine for TBG binding: ligand binding assay and computational data. Clin Biochem 2001; 34:603-6. [PMID: 11849618 DOI: 10.1016/s0009-9120(01)00277-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVE Tamoxifen, a nonesteroidal antiesterogen, is widely used in the treatment of breast cancer. Recently, the effect of tamoxifen on thyroid function has caused considerable concern, yet the results of different studies are controversial and the precise mechanism of such influence is obscure. In view of the fact that some drugs such as furosemide, diclofenac and mefenamic acid, based on the structural similarities to thyroxine could compete for binding to thyroxine binding globulin (TBG) and appears that there are some structural similarities between tamoxifen and thyroxine, one can hypothesize that tamoxifen is also able to compete for TBG binding and thereby affecting thyroid function tests. DESIGN AND METHODS In this study, we designed an in vitro binding assay as well as computational methods using MOPAC 7 package for evaluation of competitive potency of tamoxifen for TBG binding in comparison with well-known TBG competitors (including furosemide, mefenamic acid and diclofenac). RESULTS The result of competition assay and Scatchard analysis revealed that tamoxifen does not bind to TBG at the T4 binding site, thus it is not a thyroxine competitor. Computational results also indicated that structural characteristics of tamoxifen are significantly different from those of T4 and its well-known competitors. CONCLUSION In conclusion, the probability of competition between tamoxifen and T4 is ruled out by these results.
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Affiliation(s)
- F Karami-Tehrani
- Cancer Research Laboratory, Clinical Biochemistry Department, School of Medical Sciences, Tarbiat Modarres University, Tehran, Iran.
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26
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Abstract
The use of tamoxifen among women with breast cancer or at high risk of the disease has greatly expanded over the past several decades. Tamoxifen has a complex effect on the female reproductive tract and several tamoxifen-associated changes have been described among tamoxifen users. These include endometrial thickening, cervical and endometrial polyps, endometrial hyperplasia, endometrial adenocarcinoma, uterine sarcoma, increase in the size of uterine leiomyomata, exacerbation of endometriosis and ovarian cysts. The most common uterine change associated with tamoxifen is endometrial polyps. The annual incidence of endometrial cancer among women on tamoxifen is 2 per 1000 and seems to be related to the cumulative tamoxifen dose. It is not clear whether endometrial cancer occurring among women on tamoxifen is of worse prognosis than endometrial cancer occurring among women not receiving tamoxifen. Tamoxifen is associated with several sonographic changes which make the use of ultrasound in surveillance of these patients difficult. There is no indication to implement routine screening for endometrial cancer among all women on tamoxifen. However, endometrial biopsy, preferably via hysteroscopy, should be considered in women with uterine bleeding.
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Affiliation(s)
- G H Eltabbakh
- Department of Pathology, University of Vermont College of Medicine, Burlington, USA
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O'Day SJ, Boasberg PD, Kristedja TS, Martin M, Wang HJ, Fournier P, Cabot M, DeGregorio MW, Gammon G. High-dose tamoxifen added to concurrent biochemotherapy with decrescendo interleukin-2 in patients with metastatic melanoma. Cancer 2001; 92:609-19. [PMID: 11505406 DOI: 10.1002/1097-0142(20010801)92:3<609::aid-cncr1361>3.0.co;2-u] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND In vitro cell culture data and preclinical models suggest that tamoxifen modulates tumor cell sensitivity to a wide range of therapeutic agents. In the current study, the authors examined whether high-dose tamoxifen (HDT) improved the overall and complete response in patients with metastatic melanoma who were treated with concurrent biochemotherapy. METHODS Forty-nine patients were treated with a biochemotherapy regimen of dacarbazine, vinblastine, cisplatin, decrescendo interleukin-2, interferon-alpha-2b, and tamoxifen. The study had a 2-step design, beginning with a tamoxifen dose escalation from 40 mg to 320 mg (17 subjects) to evaluate safety and tolerability, followed by Phase II accrual of 32 patients to HDT (320 mg) to assess clinical efficacy. Efficacy was compared with a similar modified biochemotherapy regimen with low-dose tamoxifen (LDT). Pharmacokinetic studies were performed to determine in vivo tamoxifen levels. RESULTS Tamoxifen dose escalation was completed without any reported dose-limiting toxicity. The overall response rate in the HDT group was 50% (95% confidence interval, 33.2%-66.8%), with a complete response rate of 6% and a median survival of 9.5 months. The overall response rate was not improved and the complete response and survival appeared inferior compared with that of patients recently treated with concurrent biochemotherapy and LDT. Serum tamoxifen levels were found to correlate with the dose administered, with a mean of 0.9 microM at the 40-mg dose to 4.6 microM at the 320-mg dose. Ultrafiltered protein-free sera demonstrated low (< 0.01 microM) concentrations of tamoxifen. CONCLUSIONS The addition of HDT to a regimen of concurrent biochemotherapy did not appear to improve response rates or overall survival, despite reaching the targeted plasma concentration. Unknown drug interactions or high protein binding of tamoxifen may account for the lack of clinical effectiveness.
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Affiliation(s)
- S J O'Day
- Division of Medical Oncology, John Wayne Cancer Institute at Saint John's Health Center, 2001 Santa Monica Blvd., Santa Monica, CA 90404, USA.
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Dietze EC, Caldwell LE, Grupin SL, Mancini M, Seewaldt VL. Tamoxifen but not 4-hydroxytamoxifen initiates apoptosis in p53(-) normal human mammary epithelial cells by inducing mitochondrial depolarization. J Biol Chem 2001; 276:5384-94. [PMID: 11094056 DOI: 10.1074/jbc.m007915200] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Despite the widespread clinical use of tamoxifen as a breast cancer prevention agent, the molecular mechanism of tamoxifen chemoprevention is poorly understood. Abnormal expression of p53 is felt to be an early event in mammary carcinogenesis. We developed an in vitro model of early breast cancer prevention to investigate how tamoxifen and 4-hydroxytamoxifen may act in normal human mammary epithelial cells (HMECs) that have acutely lost p53 function. p53 function was suppressed by retrovirally mediated expression of the human papillomavirus type 16 E6 protein. Tamoxifen, but not 4-hydroxytamoxifen, rapidly induced apoptosis in p53(-) HMEC-E6 cells as evidenced by characteristic morphologic changes, annexin V binding, and DNA fragmentation. We observed that a decrease in mitochondrial membrane potential, mitochondrial condensation, and caspase activation preceded the morphologic appearance of apoptosis in tamoxifen-treated early passage p53(-) HMEC-E6 cells. p53(-) HMEC-E6 cells rapidly developed resistance to tamoxifen-mediated apoptosis within 10 passages in vitro. Resistance to tamoxifen in late passage p53(-) HMEC-E6 cells correlated with an increase in mitochondrial mass and a lack of mitochondrial depolarization and caspase activation following tamoxifen treatment. We hypothesize that an early event in the induction of apoptosis by tamoxifen involves mitochondrial depolarization and caspase activation, and this may be important for effective chemoprevention.
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Affiliation(s)
- E C Dietze
- Program in Chemical Biology and Division of Medical Oncology, Duke University, Durham, NC 27710, USA
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Frank MH, Denton MD, Alexander SI, Khoury SJ, Sayegh MH, Briscoe DM. Specific MDR1 P-glycoprotein blockade inhibits human alloimmune T cell activation in vitro. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:2451-9. [PMID: 11160305 DOI: 10.4049/jimmunol.166.4.2451] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
MDR1 P-glycoprotein (P-gp), the multidrug resistance-associated transmembrane transporter, is physiologically expressed by human peripheral immune cells, but its role in cell-mediated immunity remains poorly understood. Here, we demonstrate a novel role for P-gp in alloantigen-dependent human T cell activation. The pharmacologic P-gp inhibitor tamoxifen (1-10 microM) and the MDR1 P-gp-specific mAb Hyb-241 (1-20 microg/ml), which detected surface P-gp on 21% of human CD3(+) T cells and 84% of CD14(+) APCs in our studies, inhibited alloantigen-dependent, but not mitogen-dependent, T cell proliferation in a dose-dependent manner from 40-90% (p < 0.01). The specific inhibitory effect on alloimmune T cell activation was associated with >85% inhibition (p < 0.01) of IL-2, IFN-gamma, and TNF-alpha production in 48-h MLR coculture supernatants. Addition of recombinant human IL-2 (0.1-10 ng/ml) restored proliferation in tamoxifen-treated cocultures. Pretreatment of purified CD4(+) T cells with Hyb-241 mAb before coculture resulted in inhibition of CD4(+) T cellular IFN-gamma secretion. Also, blockade of P-gp on allogeneic APCs inhibited IL-12 secretion. Taken together these results demonstrate that P-gp is functional on both CD4(+) T cells and CD14(+) APCs, and that P-gp blockade may attenuate both IFN-gamma and IL-12 through a positive feedback loop. Our results define a novel role for P-gp in alloimmunity and thus raise the intriguing possibility that P-gp may represent a novel therapeutic target in allograft rejection.
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Affiliation(s)
- M H Frank
- Division of Nephrology, Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
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30
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Barakat RR, Gilewski TA, Almadrones L, Saigo PE, Venkatraman E, Hudis C, Hoskins WJ. Effect of adjuvant tamoxifen on the endometrium in women with breast cancer: a prospective study using office endometrial biopsy. J Clin Oncol 2000; 18:3459-63. [PMID: 11032585 DOI: 10.1200/jco.2000.18.20.3459] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE To determine the frequency of developing abnormal pathologic changes in the endometria of tamoxifen-treated women. To characterize the type of pathologic changes involved. PATIENTS AND METHODS Between October 1991 and September 1998, 159 patients initiating tamoxifen therapy for breast cancer confined to the breast and axillary lymph nodes were entered in a prospective study. In this study, office endometrial biopsies (EMBs) were obtained during the initiation of tamoxifen and at 6-month intervals for a 2-year period. Three subsequent annual EMBs were recorded for each patient, amounting to a 5-year surveillance. RESULTS One hundred fifty-nine patients with a median age of 50 years were entered onto study. Patients were assessable if EMBs were performed at least 1 year after the initiation of tamoxifen treatment. Nine patients (5. 7%) were considered protocol violations. The remaining 111 assessable patients underwent a total of 635 EMBs (mean, 5.8 EMBs), with a median surveillance time of 36 months. Eighty-two (12.9%) of the 635 biopsies revealed tissue insufficient for diagnosis. Fourteen patients (12.6%) underwent dilation and curettage (D&C) for an abnormal EMB, persistent bleeding, or for evaluation of adnexal masses at the time of laparoscopy. Findings at D&C included complex hyperplasia (n = 1), abnormal histiocytes (n = 1), simple hyperplasia (n = 2), polyps (n = 4), endocervical polyp (n = 1), and decidualization (n = 2). Three D&Cs were negative. Three patients have undergone hysterectomy. CONCLUSION EMB was used to monitor the endometrium in the majority (95%) of breast cancer patients on tamoxifen in this trial, but the utility of routine EMB for screening in tamoxifen-treated women seems limited.
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Affiliation(s)
- R R Barakat
- Gynecology Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA.
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31
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Abstract
Tamoxifen is an antiestrogenic drug which is used in the treatment of breast cancer and nonmalignant breast disorders. It also has a stimulating effect on the secretion of hypofisar gonadotropic hormones and is generally used in the treatment of infertility. In males, tamoxifen causes an increase of endogenous production of androgenic steroids, and therefore is used by athletes. A method for identification of tamoxifen and metabolites in urine, using the gas chromatography and mass spectrometry system (GC/MS) is described. This study also reports the extraction methodology of tamoxifen and metabolites in urine samples of healthy male volunteers and the GC/MS conditions used to identify tamoxifen and its metabolites.
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Affiliation(s)
- R Mihailescu
- Doping Control Laboratory, Sport Research Center, Bucharest, Romania
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Newton HB, Turowski RC, Stroup TJ, McCoy LK. Clinical presentation, diagnosis, and pharmacotherapy of patients with primary brain tumors. Ann Pharmacother 1999; 33:816-32. [PMID: 10466912 DOI: 10.1345/aph.18353] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVE To briefly review the clinical presentation and diagnosis of patients with primary brain tumors, followed by an in-depth survey of the pertinent pharmacotherapy. DATA SOURCES A detailed search of the neurologic, neurosurgical, and oncologic literature for basic science research, clinical studies, and review articles related to chemotherapy and pharmacotherapy of primary brain tumors. STUDY SELECTION Relevant studies on tissue culture systems, animals, and humans examining the mechanisms of action, pharmacokinetics, clinical pharmacology, and treatment results of chemotherapeutic agents for primary brain tumors. In addition, studies of pharmacologic agents administered for supportive care and symptom control are reviewed. DATA SYNTHESIS Primary brain tumors derive from cells within the intracranial cavity and generally present with headache, seizure activity, cognitive changes, and weakness. They are diagnosed most efficiently with magnetic resonance imaging. After diagnosis, the most common supportive medications include corticosteroids, gastric acid inhibitors, and anticonvulsants. Chemotherapy is adjunctive treatment for patients with malignant tumors and selected recurrent or progressive benign neoplasms. In general, the most effective chemotherapeutic drugs are alkylating agents such as the nitrosoureas, procarbazine, cisplatin, and carboplatin. Other agents used include cyclophosphamide, methotrexate, vincristine, and etoposide. Angiogenesis inhibitors and gene therapy comprise some of the novel therapeutic strategies under investigation. CONCLUSIONS The efficacy of chemotherapy for primary brain tumors remains modest. Novel agents must be discovered that are more specific and attack tumor cells at the molecular level of tumorigenesis. Furthermore, strategies must be developed to counteract the pervasive problem of brain tumor chemoresistance.
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Affiliation(s)
- H B Newton
- Department of Neurology, The Ohio State University, Columbus 43210, USA.
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