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Baghban Rahimi S, Mohebbi A, Vakilzadeh G, Biglari P, Razeghi Jahromi S, Mohebi SR, Shirian S, Gorji A, Ghaemi A. Enhancement of therapeutic DNA vaccine potency by melatonin through inhibiting VEGF expression and induction of antitumor immunity mediated by CD8+ T cells. Arch Virol 2017; 163:587-597. [PMID: 29149434 DOI: 10.1007/s00705-017-3647-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2017] [Accepted: 10/04/2017] [Indexed: 12/18/2022]
Abstract
To be effective, therapeutic cancer vaccines should stimulate both an effective cell-mediated and a robust cytotoxic CD8+ T-cell response against human papillomavirus (HPV)-infected cells to treat the pre-existing tumors and prevent potential future tumors. In this study, the therapeutic experiments were designed in order to evaluate antitumor effect against the syngeneic TC-1 tumor model. The anti-tumor efficacy of a HPV-16 E7 DNA vaccine adjuvanted with melatonin (MLT) was evaluated in a C57BL/6 mouse tumor model by measuring tumor growth post vaccination and the survival rate of tumor-bearing mice, analyzing the specific lymphocyte proliferation responses in control and vaccinated mice by MTT assay. The E7-specific cytotoxic T cells (CTL) were analyzed by lymphocyte proliferation and lactate dehydrogenates (LDH) release assays. IFN-γ, IL-4 and TNF-α secretion in splenocyte cultures as well as vascular endothelial growth factor (VEGF) and IL-10 in the tumor microenvironment were assayed by ELISA. Our results demonstrated that subcutaneous administration of C57BL/6 mice with a DNA vaccine adjuvanted with MLT dose-dependently and significantly induced strong HPV16 E7-specific CD8+ cytotoxicity and IFN-γ and TNF-α responses capable of reducing HPV-16 E7-expressing tumor volume. A significantly higher level of E7-specific T-cell proliferation was also found in the adjuvanted vaccine group. Furthermore, tumor growth was significantly inhibited when the DNA vaccine was combined with MLT and the survival time of TC-1 tumor bearing mice was also significantly prolonged. In vivo studies further demonstrated that MLT decreased the accumulation of IL-10 and VEGF in the tumor microenvironment of vaccinated mice. These data indicate that melatonin as an adjuvant augmented the cancer vaccine efficiency against HPV-associated tumors in a dose dependent manner.
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Affiliation(s)
- Sanaz Baghban Rahimi
- Department of Microbiology, Golestan University of Medical Sciences, Gorgan, Iran
| | - Alireza Mohebbi
- Department of Microbiology, Golestan University of Medical Sciences, Gorgan, Iran.,Department of Virology, Pasteur Institute of Iran, P.O. Box: 1316943551, Tehran, Iran
| | - Gelareh Vakilzadeh
- Department of Neuroscience, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran.,Shefa Neuroscience Research Center, Khatam Alanbia Hospital, Tehran, Iran
| | - Peyvand Biglari
- Department of Virology, Pasteur Institute of Iran, P.O. Box: 1316943551, Tehran, Iran
| | | | - Seyed Reza Mohebi
- Gastroenterology and Liver Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Sadegh Shirian
- Department of Pathology, School of Veterinary Medicine, Shahrekord University, Shahrekord, Iran
| | - Ali Gorji
- Shefa Neuroscience Research Center, Khatam Alanbia Hospital, Tehran, Iran.,Department of Neurosurgery and Neurology, Westfälische Wilhelms-Universität Münster, Robert-Koch-Strasse 27a, 48149, Münster, Germany
| | - Amir Ghaemi
- Department of Virology, Pasteur Institute of Iran, P.O. Box: 1316943551, Tehran, Iran. .,Department of Microbiology, Infectious Diseases Research Center, Golestan University of Medical Sciences, Gorgan, Iran.
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2
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Samuelsson LB, Bovbjerg DH, Roecklein KA, Hall MH. Sleep and circadian disruption and incident breast cancer risk: An evidence-based and theoretical review. Neurosci Biobehav Rev 2017; 84:35-48. [PMID: 29032088 DOI: 10.1016/j.neubiorev.2017.10.011] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 09/26/2017] [Accepted: 10/11/2017] [Indexed: 02/08/2023]
Abstract
Opportunities for restorative sleep and optimal sleep-wake schedules are becoming luxuries in industrialized cultures, yet accumulating research has revealed multiple adverse health effects of disruptions in sleep and circadian rhythms, including increased risk of breast cancer. The literature on breast cancer risk has focused largely on adverse effects of night shift work and exposure to light at night (LAN), without considering potential effects of associated sleep disruptions. As it stands, studies on breast cancer risk have not considered the impact of both sleep and circadian disruption, and the possible interaction of the two through bidirectional pathways, on breast cancer risk in the population at large. We review and synthesize this literature, including: 1) studies of circadian disruption and incident breast cancer; 2) evidence for bidirectional interactions between sleep and circadian systems; 3) studies of sleep and incident breast cancer; and 4) potential mechanistic pathways by which interrelated sleep and circadian disruption may contribute to the etiology of breast cancer.
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Affiliation(s)
- Laura B Samuelsson
- Department of Psychology, University of Pittsburgh, Pittsburgh, PA, United States
| | - Dana H Bovbjerg
- Department of Psychology, University of Pittsburgh, Pittsburgh, PA, United States; Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, United States; Department of Behavioral & Community Health Sciences, University of Pittsburgh, Pittsburgh, PA, United States; Biobehavioral Oncology Program, University of Pittsburgh Cancer Institute, University of Pittsburgh, Pittsburgh, PA, United States
| | - Kathryn A Roecklein
- Department of Psychology, University of Pittsburgh, Pittsburgh, PA, United States; Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, United States
| | - Martica H Hall
- Department of Psychology, University of Pittsburgh, Pittsburgh, PA, United States; Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, United States.
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3
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Oprea-Ilies G, Haus E, Sackett-Lundeen L, Liu Y, McLendon L, Busch R, Adams A, Cohen C. Expression of melatonin receptors in triple negative breast cancer (TNBC) in African American and Caucasian women: relation to survival. Breast Cancer Res Treat 2012; 137:677-87. [PMID: 23250547 PMCID: PMC3552359 DOI: 10.1007/s10549-012-2371-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2012] [Accepted: 12/03/2012] [Indexed: 01/10/2023]
Abstract
In the normal rodent breast, the pineal hormone melatonin controls the development of ductal and alveolar tissue. Melatonin counteracts tumor occurrence and tumor cell progression in vivo and in vitro in animal and human breast cancer cell cultures. It acts predominantly through its melatonin MT1 receptor. Our aim was to investigate the presence or absence of the MT1 melatonin receptor in the aggressive triple negative group of human breast carcinoma (TNBC) and its possible relationship to the course of the disease. A total of 167 patients with a ER−, PR−, Her-2/neu− phenotype in which tissue for receptor studies was available were examined. The MT1 receptor immunostain was evaluated semiquantitatively as staining intensity (0, 1, 2, 3), percentage of stained cells and the weighted index (WI) (staining intensity times percentage of stained cells). A score of WI < 60 was regarded as “negative”. There was a striking difference in incidence of MT1 positivity and staining intensity between carcinomas in African American (AA) and Caucasian (C) women. The AA showed a higher incidence of MT1 negative tumors (41/84 = 48.8 % in AA, 6/51 = 11.8 % in C) and a lower average WI. MT1 positivity in TNBC was associated with a lower stage and a smaller tumor size at time of diagnosis. In multivariable survival analysis, MT1 negative TNBC in all cases regardless of race showed a significantly higher hazard ratio for disease progression, shorter progression free survival, and disease-related death, and shorter OS. This was especially pronounced in the AA group but did not reach statistical significance in the smaller group of C alone. These results suggest that melatonin or a melatonin receptor agonist may be useful biologic additions in the treatment of some forms of TNBC, especially in AA who generally show a more aggressive course of their disease.
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Affiliation(s)
- Gabriela Oprea-Ilies
- Department of Pathology, Emory University School of Medicine, Emory University and Winship Cancer Institute, 1364 Clinton Road, NE, Atlanta, GA 30322 USA
| | - Erhard Haus
- Department of Lab Medicine and Pathology, University of Minnesota, Minneapolis, MN USA
- HealthPartners Institute for Education and Research, Minneapolis, MN USA
- Department of Pathology, Regions Hospital, 640 Jackson Street, St. Paul, MN 55101 USA
| | - Linda Sackett-Lundeen
- Department of Pathology, Regions Hospital, 640 Jackson Street, St. Paul, MN 55101 USA
| | - Yuan Liu
- Biostatistics and Bioinformatics Department, Winship Cancer Institute, Atlanta, GA 30322 USA
| | - Lauren McLendon
- Department of Surgery, Emory University School of Medicine, 1364 Clifton Road NE, Room H120, NE, Atlanta, GA 30322 USA
| | - Robert Busch
- Fellowship Training Program, Division of Pulmonary and Critical Care Medicine, Harvard Pulmonary and Critical Care Medicine, 55 Fruit St BUL-148, Boston, MA 02114 USA
| | - Amy Adams
- Department of Pathology, Emory University Hospital H185A, Emory University School of Medicine, 1364 Clifton Road NE, Atlanta, GA 30322 USA
| | - Cynthia Cohen
- Anatomic Pathology, Department of Pathology, G144A EUH, Emory University School of Medicine, 1364 Clifton Road NE, Atlanta, GA 30322 USA
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4
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Hill SM, Cheng C, Yuan L, Mao L, Jockers R, Dauchy B, Frasch T, Blask DE. Declining melatonin levels and MT1 receptor expression in aging rats is associated with enhanced mammary tumor growth and decreased sensitivity to melatonin. Breast Cancer Res Treat 2011; 127:91-8. [PMID: 20549340 DOI: 10.1007/s10549-010-0958-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2010] [Accepted: 05/14/2010] [Indexed: 10/19/2022]
Abstract
Serum melatonin (MLT) levels have been reported to diminish significantly by the 5th and 6th decades of life as the incidence of breast cancer increases. Given MLT's anti-cancer activity, we hypothesize that age-related decline in pineal MLT production leads to enhanced breast cancer development and growth as women age. In this study, we sought to determine whether the growth of tissue-isolated mammary tumors in young, adult, and old female Buffalo rats relates to the age-related changes in MLT and its MT1 receptor. Significant decreases in the peak nighttime serum MLT levels were observed in old as compared to adult and young rats. Significantly diminished nighttime and early morning levels of MT1-melatonin receptors were observed in uteri from old rats compared to adult and young rats. Growth rates in transplanted, tissue-isolated, carcinogen-induced mammary tumors are significantly increased in old rats as compared to adult or young rats. The growth-suppressive actions of exogenous MLT are diminished in old rats compared to adult and young rats. This decrease in tumor response correlates with reduced expression of the MT1 receptor in old as compared to young and adult rats. Thus, enhanced mammary tumor growth is associated with old age and diminished levels of MLT and MT1 receptor during old age, resulting in reduced sensitivity to exogenous MLT. Finally, our studies demonstrate that the tissue-isolated tumor model is viable model system in which to study the role of aging on breast cancer growth.
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Affiliation(s)
- Steven M Hill
- Department of Structural and Cellular Biology, Tulane University School of Medicine, 1430 Tulane Ave, SL-49, New Orleans, LA 70112, USA
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5
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Mao L, Cheng Q, Guardiola-Lemaître B, Schuster-Klein C, Dong C, Lai L, Hill SM. In vitro and in vivo antitumor activity of melatonin receptor agonists. J Pineal Res 2010; 49:210-21. [PMID: 20609073 DOI: 10.1111/j.1600-079x.2010.00781.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Melatonin has been shown to inhibit the proliferation of estrogen receptor α (ERα)-positive human breast cancer cells in vitro and suppress the growth of carcinogen-induced mammary tumors in rats. Melatonin's antiproliferative effect is mediated, at least in part, through the MT1 melatonin receptor and mechanisms involving modulation of the estrogen-signaling pathway. To develop melatonin analogs with greater therapeutic effects, we have examined the in vitro and in vivo antimitotic activity of two MT1/MT2 melatonin receptor agonists, S23219-1 and S23478-1. In our studies, both agonists are quite effective at suppressing the growth of MCF-7 human breast cancer cells. At a concentration of 10⁻⁶ m, S23219-1 and S23478-1 inhibited the growth of MCF-7 cells by 60% and 73%, respectively. However, S23478-1 is more effective than melatonin and S23219-1 at repressing the expression and transactivation of the ERα, and modulating the expression of pancreatic spasmolytic polypeptide (pS2), an estrogen-regulated gene. The melatonin agonist S23478-1 exhibited enhanced antitumor potency in the subsequent studies in our animal model. At a dosage of 25 mg/kg/day, S23478-1 is more efficacious than melatonin at inducing regression of the established N-nitroso-N-methyl-urea-induced rat mammary tumors. This dose of S23478-1 (25 mg/kg/day) generated a significant (P < 0.05) overall regression response of 52%. Furthermore, at this dosage, S23478-1 is more effective than melatonin at suppressing the estrogen-signaling pathway and promoting tumor cell apoptosis, significantly increasing the expression of the pro-apoptotic protein Bax, while decreasing the expression of ERα and the anti-apoptotic protein Bcl-2.
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Affiliation(s)
- Lulu Mao
- Department of Structural & Cellular Biology, Tulane University Health Sciences Center, 1430 Tulane Avenue, New Orleans, LA 70112, USA
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6
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Campos-Vega R, Loarca-Piña G, Oomah BD. Minor components of pulses and their potential impact on human health. Food Res Int 2010. [DOI: 10.1016/j.foodres.2009.09.004] [Citation(s) in RCA: 173] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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7
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Dauchy RT, Blask DE, Dauchy EM, Davidson LK, Tirrell PC, Greene MW, Tirrell RP, Hill CR, Sauer LA. Antineoplastic effects of melatonin on a rare malignancy of mesenchymal origin: melatonin receptor-mediated inhibition of signal transduction, linoleic acid metabolism and growth in tissue-isolated human leiomyosarcoma xenografts. J Pineal Res 2009; 47:32-42. [PMID: 19486272 DOI: 10.1111/j.1600-079x.2009.00686.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Melatonin provides a circadian signal that regulates linoleic acid (LA)-dependent tumor growth. In rodent and human cancer xenografts of epithelial origin in vivo, melatonin suppresses the growth-stimulatory effects of linoleic acid (LA) by blocking its uptake and metabolism to the mitogenic agent, 13-hydroxyoctadecadienoic acid (13-HODE). This study tested the hypothesis that both acute and long-term inhibitory effects of melatonin are exerted on LA transport and metabolism, and growth activity in tissue-isolated human leiomyosarcoma (LMS), a rare, mesenchymally-derived smooth muscle tissue sarcoma, via melatonin receptor-mediated inhibition of signal transduction activity. Melatonin added to the drinking water of female nude rats bearing tissue-isolated LMS xenografts and fed a 5% corn oil (CO) diet caused the rapid regression of these tumors (0.17 +/- 0.02 g/day) versus control xenografts that continued to grow at 0.22 +/- 0.03 g/day over a 10-day period. LMS perfused in situ for 150 min with arterial donor blood augmented with physiological nocturnal levels of melatonin showed a dose-dependent suppression of tumor cAMP production, LA uptake, 13-HODE release, extracellular signal-regulated kinase (ERK 1/2), mitogen activated protein kinase (MEK), Akt activation, and [(3)H]thymidine incorporation into DNA and DNA content. The inhibitory effects of melatonin were reversible and preventable with either melatonin receptor antagonist S20928, pertussis toxin, forskolin, or 8-Br-cAMP. These results demonstrate that, as observed in epithelially-derived cancers, a nocturnal physiological melatonin concentration acutely suppress the proliferative activity of mesenchymal human LMS xenografts while long-term treatment of established tumors with a pharmacological dose of melatonin induced tumor regression via a melatonin receptor-mediated signal transduction mechanism involving the inhibition of tumor LA uptake and metabolism.
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Affiliation(s)
- Robert T Dauchy
- Laboratory of Chrono-Neuroendocrine Oncology, Department of Structural and Cellular Biology, Tulane University School of Medicine, Tulane Cancer Center, Louisiana Cancer Research Consortium, New Orleans, LA 70112-2699, USA.
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8
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Stevens RG. Electric light causes cancer? Surely you're joking, Mr. Stevens. Mutat Res 2009; 682:1-6. [PMID: 19401186 DOI: 10.1016/j.mrrev.2009.01.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/07/2009] [Indexed: 02/02/2023]
Abstract
Night is no longer dark in the modern world, and the Milky Way has disappeared. Electric light has benefits but there are also a few detriments. These are (1) loss of the night sky, (2) wasted energy, (3) harm to animal and plant life, (4) and perhaps increases in some severe human maladies such as cancers of breast and prostate. The science on phototransduction for the circadian system and on clock gene function is evolving rapidly, and it provides a rationale for the idea that circadian disruption from light at night could cause disease. Direct evidence from humans and rodent models has also accumulated to the point where the idea is no longer fanciful. Although it may seem logical now, the journey on the path from electric light to breast cancer has been a tortuous one, at least for me.
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Affiliation(s)
- Richard G Stevens
- Department of Community Medicine and Health Care, University of Connecticut Health Center, School of Medicine, 263 Farmington Avenue, Farmington, CT 06030-6325, USA.
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9
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Martín-Renedo J, Mauriz JL, Jorquera F, Ruiz-Andrés O, González P, González-Gallego J. Melatonin induces cell cycle arrest and apoptosis in hepatocarcinoma HepG2 cell line. J Pineal Res 2008; 45:532-40. [PMID: 19012662 DOI: 10.1111/j.1600-079x.2008.00641.x] [Citation(s) in RCA: 158] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Melatonin reduces proliferation in many different cancer cell lines. However, studies on the oncostatic effects of melatonin in the treatment of hepatocarcinoma are limited. In this study, we examined the effect of melatonin administration on HepG2 human hepatocarcinoma cells, analyzing cell cycle arrest, apoptosis and mitogen-activated protein kinase (MAPK) signalling pathways. Melatonin was dissolved in the cell culture media in 0.2% dimethyl sulfoxide and administered at different concentrations for 2, 4, 6, 8 and 10 days. Melatonin at concentrations 1000-10,000 microM caused a dose- and time-dependent reduction in cell number. Furthermore, melatonin treatment induced apoptosis with increased caspase-3 activity and poly(ADP-ribose) polymerase proteolysis. Proapoptotic effects of melatonin were related to cytosolic cytochrome c release, upregulation of Bax and induction of caspase-9 activity. Melatonin treatment also resulted in increased caspase-8 activity, although no significant change was observed in Fas-L expression. In addition, JNK 1,-2 and -3 and p38, members of the MAPK family, were upregulated by melatonin treatment. Growth inhibition by melatonin altered the percentage or cells in G0-G1 and G2/M phases indicating cell cycle arrest in the G2/M phase. The reduced cell proliferation and alterations of cell cycle were coincident with a significant increase in the expression of p53 and p21 proteins. These novel findings show that melatonin, by inducing cell death and cell cycle arrest, might be useful as adjuvant in hepatocarcinoma therapy.
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Affiliation(s)
- Javier Martín-Renedo
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, Institute of Biomedicine, University of León, León, Spain.
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Abstract
Glucocorticoids (GCs) are provided as co-medication with chemotherapy in breast cancer, albeit
several lines of evidence indicate that their use may have diverse effects and in fact may inhibit
chemosensitivity. The molecular basis of GC-induced resistance to chemotherapy in breast cancer
remains poorly defined. Recent researchers, in an attempt to clarify some aspects of the underlying
pathways, provide convincing evidence that GCs induce effects that are dependent upon the
glucocorticoid-receptor (GR)-mediated transcriptional regulation of specific genes known to play key
roles in cellular/tissue functions, including growth, apoptosis, differentiation, metastasis and
cell survival. In this review, we focus on how GC-induced chemoresistance in breast cancer is
mediated by the GR, unravelling the molecular interplay of GR signalling with other signalling
cascades prevalent in breast cancer. We also include a detailed description of GR structure and
function, summarizing data gained during recent years into the mechanism(s) of the cross-talk
between the GR and other signalling cascades and secondary messengers, via which
GCs exert their pleiotropic effects.
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Affiliation(s)
- Paraskevi Moutsatsou
- Department of Biological Chemistry, Medical School, University of Athens, Athens, Greece.
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Anisimov VN, Popovich IG, Zabezhinski MA, Anisimov SV, Vesnushkin GM, Vinogradova IA. Melatonin as antioxidant, geroprotector and anticarcinogen. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2006; 1757:573-89. [PMID: 16678784 DOI: 10.1016/j.bbabio.2006.03.012] [Citation(s) in RCA: 161] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2006] [Revised: 03/14/2006] [Accepted: 03/16/2006] [Indexed: 01/03/2023]
Abstract
The effect of the pineal indole hormone melatonin on the life span of mice, rats and fruit flies has been studied using various approaches. It has been observed that in female CBA, SHR, SAM and transgenic HER-2/neu mice long-term administration of melatonin was followed by an increase in the mean life span. In rats, melatonin treatment increased survival of male and female rats. In D. melanogaster, supplementation of melatonin to nutrient medium during developmental stages produced contradictory results, but and increase in the longevity of fruit flies has been observed when melatonin was added to food throughout the life span. In mice and rats, melatonin is a potent antioxidant both in vitro and in vivo. Melatonin alone turned out neither toxic nor mutagenic in the Ames test and revealed clastogenic activity at high concentration in the COMET assay. Melatonin has inhibited mutagenesis and clastogenic effect of a number of indirect chemical mutagens. Melatonin inhibits the development of spontaneous and 7-12-dimethlbenz(a)anthracene (DMBA)- or N-nitrosomethylurea-induced mammary carcinogenesis in rodents; colon carcinogenesis induced by 1,2-dimethylhydrazine in rats, N-diethylnitrosamine-induced hepatocarcinogenesis in rats, DMBA-induced carcinogenesis of the uterine cervix and vagina in mice; benzo(a)pyrene-induced soft tissue carcinogenesis and lung carcinogenesis induced by urethan in mice. To identify molecular events regulated by melatonin, gene expression profiles were studied in the heart and brain of melatonin-treated CBA mice using cDNA gene expression arrays (15,247 and 16,897 cDNA clone sets, respectively). It was shown that genes controlling the cell cycle, cell/organism defense, protein expression and transport are the primary effectors for melatonin. Melatonin also increased the expression of some mitochondrial genes (16S, cytochrome c oxidases 1 and 3 (COX1 and COX3), and NADH dehydrogenases 1 and 4 (ND1 and ND4)), which agrees with its ability to inhibit free radical processes. Of great interest is the effect of melatonin upon the expression of a large number of genes related to calcium exchange, such as Cul5, Dcamkl1 and Kcnn4; a significant effect of melatonin on the expression of some oncogenesis-related genes was also detected. Thus, we believe that melatonin may be used for the prevention of premature aging and carcinogenesis.
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Affiliation(s)
- Vladimir N Anisimov
- Department of Carcinogenesis and Oncogerontology, N.N. Petrov Research Institute of Oncology, Pesochny-2, St. Petersburg 197758, Russia.
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12
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Melancon K, Cheng Q, Kiefer TL, Dai J, Lai L, Dong C, Yuan L, Collins A, Thiyagarajah A, Long S, Hill SM. Regression of NMU-induced mammary tumors with the combination of melatonin and 9-cis-retinoic acid. Cancer Lett 2005; 227:39-48. [PMID: 16051031 DOI: 10.1016/j.canlet.2005.01.005] [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] [Received: 08/18/2004] [Accepted: 01/07/2005] [Indexed: 10/25/2022]
Abstract
A significant increase in tumor regression was induced in N-nitroso-N-methylurea-induced mammary tumors in rats treated with the combination of melatonin and 9-cis-retinoic acid (9cRA). Treatment groups included: control (ethanolic saline), 9cRA (30 mg/kg chow/day), melatonin 500 microg/day, melatonin 1000 microg/day, melatonin 500 microg/day+9cRA and melatonin 1000 microg/day+9cRA. Rats treated with the lower dose of melatonin 500 microg+9cRA show the greatest degree of tumor regression (78%), with 54% undergoing complete regression and a significant increase in apoptotic cells observed by TUNEL Assay. Furthermore, tumor multiplicity and burden were significantly decreased by the combination of melatonin and 9cRA.
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Affiliation(s)
- K Melancon
- Department of Transplantation and Surgery, Mayo Clinic, Rochester, MN 555905, USA; Department of Surgery, New Orleans, LA 70112, USA
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13
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Cini G, Neri B, Pacini A, Cesati V, Sassoli C, Quattrone S, D'Apolito M, Fazio A, Scapagnini G, Provenzani A, Quattrone A. Antiproliferative activity of melatonin by transcriptional inhibition of cyclin D1 expression: a molecular basis for melatonin-induced oncostatic effects. J Pineal Res 2005; 39:12-20. [PMID: 15978052 DOI: 10.1111/j.1600-079x.2004.00206.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Melatonin is endowed with a growth inhibitory effect in MCF-7 breast cancer cells whose mechanism has been related to an antiestrogenic activity exerted by inhibition of binding of the estradiol-estrogen receptor complex to its DNA responsive element. Looking for downstream gene determinants of this effect, we performed a transcriptome profiling by high-density microarrays of estrogen-treated MCF-7 cells exposed or not to melatonin. We found that cyclin D1 was one of the main downregulated genes by melatonin. Validation experiments clearly confirm that in MCF-7 cells the estrogen-induced growth inhibitory activity of melatonin is consistently associated with inhibition of estrogen-elicited cyclin D1 induction. This effect is almost purely transcriptional. Reporter gene assays indicate that the same portion of the cyclin D1 promoter which confers estrogen sensitivity, encompassing a potential cAMP responsive element binding site, is repressed by melatonin. Transcriptional downregulation of cyclin D1 is the key molecular event for melatonin's antiproliferative activity, as this activity can be completely and selectively rescued by transient cyclin D1 overexpression. Finally, we provide indirect evidence that the effect of melatonin on the cyclin D1 promoter is mediated by the c-jun and ATF-2 proteins, known to bind the minimal estrogen-sensitive cyclin D1 promoter element. These findings establish for the first time a molecular link between melatonin and its effects on the cell cycle, providing at the same time a rationale for its use in adjuvant chemotherapy.
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Affiliation(s)
- Grazia Cini
- Department of Pathology and Experimental Oncology, University of Florence, Florence, Italy
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14
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Kiefer TL, Lai L, Yuan L, Dong C, Burow ME, Hill SM. Differential regulation of estrogen receptor alpha, glucocorticoid receptor and retinoic acid receptor alpha transcriptional activity by melatonin is mediated via different G proteins. J Pineal Res 2005; 38:231-9. [PMID: 15813899 DOI: 10.1111/j.1600-079x.2004.00198.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Melatonin has been shown to bind to the MT1 G protein-coupled receptor (GPCR) in MCF-7 breast cancer cells to modulate the estrogen response pathway suppressing estrogen-induced estrogen receptor alpha (ERalpha) transcriptional activity, blunting ER/DNA binding activity and suppressing cell proliferation. In these studies we have examined the effect of melatonin on the transcriptional activity of the ERalpha and other members of the steroid/thyroid hormone receptor superfamily, namely, the glucocorticoid receptor (GR) and the retinoic acid receptor alpha (RARalpha). As with the ERalpha, melatonin represses ligand (dexamethasone)-induced activation of the GR. This effect of melatonin on ERalpha and GR is blocked by pertussis toxin (PTX) suggesting that melatonin's actions may be mediated via a PTX-sensitive G(alphai) protein. In contrast, melatonin potentiates the action of all-trans-retinoic acid on RARalpha transcriptional activation and enhances RARalpha/DNA binding activity, an action which is not PTX-sensitive. Expression of a dominant-positive G(alphai2) protein, with which the MT1 receptor has been shown to couple, is able to mimic the effect of melatonin on ERalpha but not RARalpha transcriptional activation in breast cancer cells. This demonstrates that GPCRs can modulate the transcriptional activity of various steroid receptors in response to their ligand through activation of different G protein signaling pathways.
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Affiliation(s)
- Todd L Kiefer
- Tulane Cancer Center, Tulane University Medical School, New Orleans, LA 70112, USA
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15
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Lenoir V, Yon de Jonage-Canonico MB, Perrin MH, Martin A, Scholler R, Kerdelhué B. Preventive and curative effect of melatonin on mammary carcinogenesis induced by dimethylbenz[a]anthracene in the female Sprague-Dawley rat. Breast Cancer Res 2005; 7:R470-6. [PMID: 15987452 PMCID: PMC1175060 DOI: 10.1186/bcr1031] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2004] [Revised: 03/16/2005] [Accepted: 03/31/2005] [Indexed: 11/25/2022] Open
Abstract
Introduction It has been well documented that the pineal hormone, melatonin, which plays a major role in the control of reproduction in mammals, also plays a role in the incidence and growth of breast and mammary cancer. The curative effect of melatonin on the growth of dimethylbenz [a]anthracene-induced (DMBA-induced) mammary adenocarcinoma (ADK) has been previously well documented in the female Sprague–Dawley rat. However, the preventive effect of melatonin in limiting the frequency of cancer initiation has not been well documented. Methods The aim of this study was to compare the potency of melatonin to limit the frequency of mammary cancer initiation with its potency to inhibit tumor progression once initiation, at 55 days of age, was achieved. The present study compared the effect of preventive treatment with melatonin (10 mg/kg daily) administered for only 15 days before the administration of DMBA with the effect of long-term (6-month) curative treatment with the same dose of melatonin starting the day after DMBA administration. The rats were followed up for a year after the administration of the DMBA. Results The results clearly showed almost identical preventive and curative effects of melatonin on the growth of DMBA-induced mammary ADK. Many hypotheses have been proposed to explain the inhibitory effects of melatonin. However, the mechanisms responsible for its strong preventive effect are still a matter of debate. At least, it can be envisaged that the artificial amplification of the intensity of the circadian rhythm of melatonin could markedly reduce the DNA damage provoked by DMBA and therefore the frequency of cancer initiation. Conclusion In view of the present results, obtained in the female Sprague–Dawley rat, it can be envisaged that the long-term inhibition of mammary ADK promotion by a brief, preventive treatment with melatonin could also reduce the risk of breast cancer induced in women by unidentified environmental factors.
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Affiliation(s)
- Véronique Lenoir
- Laboratoire de neuroendocrinologie, CNRS-FRE2718, UFR Biomédicale des Saints-Pères, Université René Descartes, Paris
| | | | - Marie-Hélène Perrin
- Laboratoire de neuroendocrinologie, CNRS-FRE2718, UFR Biomédicale des Saints-Pères, Université René Descartes, Paris
| | - Antoine Martin
- Service Central d'Anatomie et de Cytologie Pathologique, Hôpital Avicenne, Bobigny, France
| | - Robert Scholler
- Laboratoire de neuroendocrinologie, CNRS-FRE2718, UFR Biomédicale des Saints-Pères, Université René Descartes, Paris
| | - Bernard Kerdelhué
- Laboratoire de neuroendocrinologie, CNRS-FRE2718, UFR Biomédicale des Saints-Pères, Université René Descartes, Paris
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16
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Rahman KMW, Sugie S, Watanabe T, Tanaka T, Mori H. Chemopreventive Effects of Melatonin on Diethylnitrosamine and Phenobarbital-Induced Hepatocarcinogenesis in Male F344 Rats. Nutr Cancer 2003; 47:148-55. [PMID: 15087267 DOI: 10.1207/s15327914nc4702_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: 10/31/2022]
Abstract
The antitumor effects of melatonin on diethylnitrosamine (DEN)-initiated and/or phenobarbital (PB)-promoted hepatocarcinogenesis were investigated in male F344 rats. Five-week-old male F344 rats were divided into eight groups. Rats in groups 1-5 were given DEN (100 mg/kg body weight, i.p.) once a week for 3 wk, whereas those in groups 6-8 received vehicle treatment. Groups 1-3 and 7 were given 500 ppm PB in drinking water for 20 wk after DEN or vehicle treatment. Group 2 was given 400 ppm melatonin-containing diet during the initiation phase. Groups 3 and 5 were fed melatonin-containing diet for 20 wk, starting 1 wk after the last dosing of DEN. Group 6 was given melatonin-containing diet alone throughout the experiment (24 wk). Group 8 was treated with vehicle alone. Liver neoplasms were recognized only in DEN-treated groups. The incidences and multiplicities of hepatocellular adenoma and hepatocellular carcinoma (HCC) in group 3 were significantly smaller when compared with group 1 (P < 0.001 or P < 0.002). The average and unit areas of glutathione S-transferase placental form (GST-P)-positive foci of groups 2 and 3 were significantly smaller than those of group 1 (P < 0.001 or P < 0.01). The density and average area of these preneoplastic lesions of group 5 were also smaller than those of group 4 (P < 0.001 or P < 0.005). In addition, the ornithine decarboxylase activity in nonneoplastic liver tissue was reduced by melatonin treatment in both the initiation and postinitiation phases. These results suggest that melatonin has an antitumor-promoting ability in DEN-initiated and PB-promoted hepatocarcinogenesis in rats.
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Affiliation(s)
- K M Wahidur Rahman
- First Department of Pathology, Gifu University School of Medicine, Gifu City 500-8705, Japan.
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17
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De Jonage-Canonico MBY, Lenoir V, Martin A, Scholler R, Kerdelhué B. Long term inhibition by estradiol or progesterone of melatonin secretion after administration of a mammary carcinogen, the dimethyl benz(a)anthracene, in Sprague-Dawley female rat; inhibitory effect of Melatonin on mammary carcinogenesis. Breast Cancer Res Treat 2003; 79:365-77. [PMID: 12846421 DOI: 10.1023/a:1024059824430] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A single intragastric administration of 7,12-dimethylbenz(a)anthracene (DMBA) has been shown to induce mammary tumors in young cycling female Sprague-Dawley rats. The appearance of the tumors is preceded by a series of neuroendocrine disturbances, including attenuation of the preovulatory Luteinizing Hormone surge and Gonadotropin-Releasing Hormone release and amplification of the preovulatory 17beta-Estradiol (E2) surge. In this study, we examined the hypothesis that a single administration of DMBA increases the E2 and Progesterone inhibition of the spontaneous and Isoproterenol-induced Melatonin (MT) secretion from the pineal gland, during the latency phase. Also, the incidence of mammary tumors, as well as the possible preventive effect of various doses of Melatonin, were recorded up to 6 months after daily administration. For all studies, Sprague-Dawley rats, 55-60 days of age, received, on the Estrous day of the Estrous cycle, a single dose of 15 mg DMBA delivered by intragastric intubation. For the study on ovarian steroids, they were ovariectomized 5 days later and then sacrificed by decapitation at 10 a.m., one month later. Pineal glands were removed and placed in perifusion chambers containing Hanks 199 medium. The medium was saturated with O2/CO2 (95%/5%) and its pH was 7.4. Ten independent chambers were immersed in a water bath at 37 degrees C. Each pineal gland received medium (flow rate: 0.16 ml/min) through a system of input lines. The fractions were collected every 10 min, and immediately frozen at -20 degrees C until Melatonin RIA. Experiments were repeated to obtain up to five experimental points for each treatment. E2 (10(-11)-10(-9) M) and Progesterone (10(-9)-10(-7) M) were applied during the entire perifusion period (7 h). Isoproterenol (10(-6) M) was applied for 20 min after 2.5 h in perifusion. Melatonin concentrations and Areas Under the Curves were compared using two-factor ANOVA as well as parametric or nonparametric two-sample methods after testing sample normality. For the study on the possible preventive effect of Melatonin, they were daily treated, by the intragastric route, with increasing doses of Melatonin for 6 months. The percentage of female rats having at least one mammary carcinoma were compared using the Fischer exact t-test. During the latency phase, in vehicle-treated rats, E2 and Progesterone treatments lead an almost significant inhibition of the Isoproterenol-induced stimulation of Melatonin secretion. In DMBA-treated rats, E2 treatment leads to a complete blunting of the Isoproterenol-induced stimulation of Melatonin and Progesterone treatment leads to a cyclic inhibition of the Isoproterenol-induced Melatonin secretion. During the promotion phase, there was a dose-dependent inhibitory effect (up to 65% inhibition) of the daily administration of Melatonin, on mammary tumors occurrence. In conclusion, the long term inhibition of DMBA upon Melatonin secretion from the pineal gland might accelerate the promotion of mammary tumors induced by the mammary carcinogen. Inversely, the daily administration of Melatonin for 6 months induces a long lasting protective effect against the formation of mammary tumors.
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MESH Headings
- 9,10-Dimethyl-1,2-benzanthracene/administration & dosage
- 9,10-Dimethyl-1,2-benzanthracene/pharmacology
- Adrenergic beta-Agonists/pharmacology
- Animals
- Antioxidants/pharmacology
- Carcinogens/administration & dosage
- Carcinogens/pharmacology
- Carcinoma/chemically induced
- Carcinoma/physiopathology
- Carcinoma/prevention & control
- Cell Transformation, Neoplastic
- Dose-Response Relationship, Drug
- Estradiol/metabolism
- Estradiol/pharmacology
- Female
- Isoproterenol/pharmacology
- Mammary Neoplasms, Animal/chemically induced
- Mammary Neoplasms, Animal/physiopathology
- Mammary Neoplasms, Animal/prevention & control
- Melatonin/metabolism
- Melatonin/pharmacology
- Pineal Gland/physiology
- Progesterone/metabolism
- Progesterone/pharmacology
- Rats
- Rats, Sprague-Dawley
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18
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Collins A, Yuan L, Kiefer TL, Cheng Q, Lai L, Hill SM. Overexpression of the MT1 melatonin receptor in MCF-7 human breast cancer cells inhibits mammary tumor formation in nude mice. Cancer Lett 2003; 189:49-57. [PMID: 12445677 DOI: 10.1016/s0304-3835(02)00502-5] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Overexpression of the MT1 melatonin receptor in MCF-7 human breast cancer cells significantly enhances the response of these cells to the growth-inhibitory actions of melatonin. Athymic nude mice implanted with MT1-overexpressing MCF-7 cells developed significantly fewer palpable tumors (60% reduction) compared to mice receiving vector-transfected MCF-7 cells (vt-MCF-7). In response to exogenous melatonin, tumor incidence in the mice receiving the MT1-overexpressing MCF-7 cells was decreased by 80% compared to mice receiving vt-MCF-7 cells. Interestingly, daily melatonin administration did not decrease tumor incidence in mice receiving vt-MCF-7 cells, but rather stimulated overall tumor formation.
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MESH Headings
- Animals
- Breast Neoplasms/prevention & control
- Female
- Humans
- Melatonin/pharmacology
- Mice
- Mice, Nude
- Neoplasm Transplantation
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/metabolism
- Receptors, Cell Surface/physiology
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/metabolism
- Receptors, Cytoplasmic and Nuclear/physiology
- Receptors, Melatonin
- Transfection
- Transplantation, Heterologous
- Tumor Cells, Cultured
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Affiliation(s)
- A Collins
- Department of Structural and Cellular Biology, Tulane University Health Sciences Center, 1430 Tulane Avenue, New Orleans, LA 70112, USA
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19
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Yuan L, Collins AR, Dai J, Dubocovich ML, Hill SM. MT(1) melatonin receptor overexpression enhances the growth suppressive effect of melatonin in human breast cancer cells. Mol Cell Endocrinol 2002; 192:147-56. [PMID: 12088876 DOI: 10.1016/s0303-7207(02)00029-1] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Melatonin inhibits the proliferation of estrogen receptor alpha (ERalpha)-positive (MCF-7), but not ERalpha-negative (MDA-MB-231) breast cancer cells. Here, we assessed the effect of MT(1) melatonin receptor stable overexpression in MCF-7 and MDA-MB-231 breast cancer cells on the growth-suppressive effects of melatonin. Parental and vector-transfected MCF-7 cells demonstrated a modest, but significant, growth-suppressive response to melatonin; however, melatonin treatment of MT(1)-transfected MCF-7 cells resulted in significantly enhanced growth-suppression. This response was blocked by an MT1/MT2 melatonin receptor antagonist. Interestingly, MT(1)-overexpression did not induce a melatonin-sensitive phenotype in melatonin-insensitive MDA-MB-231 cells. Finally, Northern blot analysis demonstrated an enhanced inhibition of ERalpha mRNA expression and an enhanced induction of pancreatic spasmolytic polypeptide (pS2) by melatonin in MT(1)-transfected MCF-7 cells relative to vector-transfected MCF-7 cells. These data suggest the involvement of the MT(1) melatonin receptor in mediation of melatonin effects on growth-suppression and gene-modulation in breast cancer cells.
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MESH Headings
- Adenocarcinoma/chemistry
- Adenocarcinoma/pathology
- Breast Neoplasms/chemistry
- Breast Neoplasms/pathology
- Cell Division/drug effects
- Estrogen Receptor alpha
- Estrogens
- Female
- Gene Expression Regulation, Neoplastic/drug effects
- Hormone Antagonists/pharmacology
- Humans
- Intercellular Signaling Peptides and Proteins
- Melatonin/pharmacology
- Mucins
- Muscle Proteins
- Naphthalenes/pharmacology
- Neoplasm Proteins/analysis
- Neoplasms, Hormone-Dependent/chemistry
- Neoplasms, Hormone-Dependent/pathology
- Neuropeptides
- Peptides/genetics
- Peptides/metabolism
- RNA, Messenger/biosynthesis
- RNA, Neoplasm/biosynthesis
- Receptors, Cell Surface/antagonists & inhibitors
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/physiology
- Receptors, Cytoplasmic and Nuclear/antagonists & inhibitors
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/physiology
- Receptors, Estrogen/analysis
- Receptors, Melatonin
- Recombinant Fusion Proteins/physiology
- Transfection
- Trefoil Factor-2
- Trefoil Factor-3
- Tumor Cells, Cultured/chemistry
- Tumor Cells, Cultured/drug effects
- Tumor Cells, Cultured/pathology
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Affiliation(s)
- Lin Yuan
- Department of Structural and Cellular Biology, Tulane University Medical School, 1430 Tulane Avenue, New Orleans, LA 70112, USA
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20
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Thomas CR, Reiter RJ, Herman TS. Melatonin: from basic research to cancer treatment clinics. J Clin Oncol 2002; 20:2575-601. [PMID: 12011138 DOI: 10.1200/jco.2002.11.004] [Citation(s) in RCA: 229] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Melatonin, the chief secretory product of the pineal gland, is a direct free radical scavenger, an indirect antioxidant, as well as an important immunomodulatory agent. In both in vitro and in vivo investigations, melatonin protected healthy cells from radiation-induced and chemotherapeutic drug-induced toxicity. Furthermore, several clinical studies have demonstrated the potential of melatonin, either alone or in combination with traditional therapy, to yield a favorable efficacy to toxicity ratio in the treatment of human cancers. This study reviews the literature from laboratory investigations that document the antioxidant and oncostatic actions of melatonin and summarizes the evidence regarding the potential use of melatonin in cancer treatment. This study also provides rationale for the design of larger translational research-based clinical trials.
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21
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Nowfar S, Teplitzky SR, Melancon K, Kiefer TL, Cheng Q, Dwived PD, Bischoff ED, Moro K, Anderson MB, Dai J, Lai L, Yuan L, Hill SM. Tumor prevention by 9-cis-retinoic acid in the N-nitroso-N-methylurea model of mammary carcinogenesis is potentiated by the pineal hormone melatonin. Breast Cancer Res Treat 2002; 72:33-43. [PMID: 12004806 DOI: 10.1023/a:1014912919470] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Our laboratory has demonstrated that treatment of MCF-7 breast cancer cells with melatonin (Mlt) followed 24h later with physiological concentrations of all-trans retinoic acid (atRA) results in apoptosis. These studies were extended into trials using the N-nitroso-N-methylurea (NMU)-induced rat mammary tumor model. Initial studies conducted by feeding the animals 9-cis-retinoic acid (9cRA in the chow) and administering melatonin by subcutaneous injection in the late afternoon demonstrated that the combination of Mlt and 9cRA was able to significantly prevent tumor development, and that the combination was more efficacious that either Mlt or 9cRA alone. In this report, we conducted studies to determine if lower doses of 9cRA could be used in combination with Mlt while still maintaining anti-tumor activity and if the route of administration of 9cRA (bolus (gavage) v.s. chronic (chow) routes) affected its interaction with Mlt. The studies presented here demonstrate that significantly reduced doses of 9cRA can be used in combination with Mlt while maintaining anti-tumor efficacy. Furthermore, our studies demonstrate that 9cRA is equally effective when it is administered chronically (chow) or as a bolus (gavage). These data demonstrate that the combined use of Mlt and 9cRA produces additive or synergistic effects, which are more efficacious than 9cRA alone. This combination of Mlt and 9cRA could be a potentially useful clinical treatment regimen for breast cancer since it allows the use of lower doses of retinoic acid, thus, avoiding the toxic side effects associated with the use of high dose retinoids.
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Affiliation(s)
- S Nowfar
- Department of Structural & Cellular Biology, Tulane University School of Medicine, New Orleans, LA 70112, USA
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22
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Kiefer T, Ram PT, Yuan L, Hill SM. Melatonin inhibits estrogen receptor transactivation and cAMP levels in breast cancer cells. Breast Cancer Res Treat 2002; 71:37-45. [PMID: 11859872 DOI: 10.1023/a:1013301408464] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We have previously demonstrated that the pineal hormone, melatonin, can inhibit the growth of estrogen receptor-alpha (ERalpha)-positive breast cancer cells and suppress ERalpha gene transcription. To investigate the relationship between the estrogen response pathway and melatonin's growth inhibition, ERalpha-positive MCF-7 human breast cancer cells were transiently transfected with an estrogen response element (ERE) luciferase reporter construct and then treated with melatonin (10(-9)-10(-6) M) for 30 min followed by 10(-9) M 17-beta-estradiol (E2) or treated with each compound alone. Melatonin pre-treatment significantly reduced E2-induced ERalpha transactivation and ERalpha-ERE binding activity. We also conducted experiments to determine if melatonin modulates cAMP levels in MCF-7 cells. Melatonin inhibited the forskolin-induced and E2-induced elevation of cAMP levels by 57 and 45%, respectively. These data indicate that melatonin can act as a biological modifier to affect ERalpha transcriptional activity by regulating signal transduction pathways which impinge on the ERalpha and by altering E2-mediated ERalpha transactivation and ERalpha DNA binding activity.
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Affiliation(s)
- T Kiefer
- Department of Structural and Cellular Biology, Tulane University School of Medicine, New Orleans, LA 70112, USA
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23
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Teplitzky SR, Kiefer TL, Cheng Q, Dwivedi PD, Moroz K, Myers L, Anderson MB, Collins A, Dai J, Yuan L, Spriggs LL, Blask DE, Hill SM. Chemoprevention of NMU-induced rat mammary carcinoma with the combination of melatonin and 9-cis-retinoic acid. Cancer Lett 2001; 168:155-63. [PMID: 11403920 DOI: 10.1016/s0304-3835(01)00548-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
In experimental trials using the N-nitroso-N-methylurea (NMU)-induced rat mammary tumor model, a significant decrease in tumor incidence (to 5%) was observed in rats treated with melatonin and 9-cis-retinoic acid (9 cRA) compared to controls (55%). Although 9cRA alone decreased tumor incidence to 26%, this response did not reach statistical significance. Tumor incidence was significantly inhibited to 20% in the animals that received melatonin and 9cRA on alternating days. Latency to tumor onset was prolonged in animals receiving either of the combination treatments compared with controls, and tumor multiplicity was also significantly decreased.
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Affiliation(s)
- S R Teplitzky
- Department of Surgery, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA 70112, USA
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24
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Hill SM, Teplitzky S, Ram PT, Kiefer T, Blask DE, Spriggs LL, Eck KM. Melatonin synergizes with retinoic acid in the prevention and regression of breast cancer. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2000; 460:345-62. [PMID: 10810532 DOI: 10.1007/0-306-46814-x_39] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- S M Hill
- Department of Anatomy, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA
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25
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Jones MP, Melan MA, Witt-Enderby PA. Melatonin decreases cell proliferation and transformation in a melatonin receptor-dependent manner. Cancer Lett 2000; 151:133-43. [PMID: 10738107 DOI: 10.1016/s0304-3835(99)00394-8] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
There are conflicting claims for the role of melatonin in oncogenesis. In addition, the mechanism(s) underlying melatonin's effects in oncogenic processes is (are) unknown. In this study, the effects of melatonin exposure on cell proliferation and transformation were assessed in NIH3T3 cells transfected with either the human mt(1) (NIH-mt1) or MT(2) (NIH-MT2) melatonin receptors. The effects of melatonin exposure on proliferation was assessed by direct cell counts and [(3)H]thymidine uptake assays. The effect of chronic melatonin pretreatment on transformation was assessed by focus assays. In both NIH-mt1 and NIH-MT2 cells, melatonin pretreatment decreased cell proliferation and transformation. Control (NIH-neo) cells did not show this effect. However, as revealed by the [(3)H]thymidine uptake assays, an increase in DNA synthesis occurred in NIH-mt1 cells, whereas no increase occurred in the NIH-MT2 or NIH-neo cells. Upon examination of melatonin receptors, a decrease in the function of both mt(1) and MT(2) receptors occurred. These data suggest that perhaps an attenuation of receptor-mediated processes are involved in the anti-proliferative and anti-transformation capabilities of melatonin in NIH3T3 cells. In addition, based on the [(3)H]thymidine assays, receptor mediated signal transduction mechanisms may slow the growth of cells via actions on the cell cycle. The results from this study shed new insight on the putative mechanisms underlying melatonin's effects on cell proliferation and transformation and lends support for a protective role of melatonin in oncogenesis.
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Affiliation(s)
- M P Jones
- Department of Pharmacology and Toxicology, Duquesne University, Pittsburgh, PA 15282, USA
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26
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Abstract
In this article we review the state of the art on the role of the pineal gland and melatonin in mammary cancer tumorigenesis in vivo as well as in vitro. The former hypothesis of a possible role of the pineal gland in mammary cancer development was based on the evidence that the pineal, via its main secretory product, melatonin, downregulates some of the pituitary and gonadal hormones which control mammary gland development and are also responsible for the growth of hormone-dependent mammary tumors. Furthermore, melatonin could act directly on tumoral cells, thereby influencing their proliferative rate. Other possible origins of melatonin's antitumoral actions could be found in its antioxidant or immunoenhancing properties. The working hypotheses of most experiments were that the activation of the pineal gland, or the administration of melatonin, should give rise to antitumoral behavior; conversely, suppression of the pineal gland or melatonin deficits should stimulate mammary tumorigenesis. From in vivo studies on animal models of tumorigenesis, the general conclusion is that experimental manipulations activating the pineal gland, or the administration of melatonin, enlarge the latency and reduce the incidence and growth rate of chemically induced mammary tumors, while pinealectomy usually has the opposite effects. The direct actions of melatonin on mammary tumors have been suggested because of its ability to inhibit, at physiological doses (1 nM), the in vitro proliferation and invasiveness of MCF-7 human breast cancer cells. The fact that most studies have been performed on two models, chemically induced mammary adenocarcinoma in rats (in vivo studies) and the cell tumor line MCF-7 (in vitro studies), makes the generalization of the results somewhat difficult. However, the characteristics of these actions, comprising different aspects of tumor biology such as initiation, proliferation, and metastasis, as well as the doses (physiological range) at which the effect is accomplished, give special value to these findings. On the strength of these data, the small number of clinical studies focusing on the possible therapeutic value of melatonin on breast cancer is surprising.
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Affiliation(s)
- S Cos
- Department of Physiology and Pharmacology, University of Cantabria, Santander, 39011, Spain
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27
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Brainard GC, Kavet R, Kheifets LI. The relationship between electromagnetic field and light exposures to melatonin and breast cancer risk: a review of the relevant literature. J Pineal Res 1999; 26:65-100. [PMID: 10100735 DOI: 10.1111/j.1600-079x.1999.tb00568.x] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Worldwide, breast cancer is the most common malignancy accounting for 20-32% of all female cancers. This review summarizes the peer-reviewed, published data pertinent to the hypothesis that increased breast cancer in industrialized countries is related to the increased use of electricity [Stevens, R.G., S. Davis 1996]. That hypothesis specifically proposes that increased exposure to light at night and electromagnetic fields (EMF) reduce melatonin production. Because some studies have shown that melatonin suppresses mammary tumorigenesis in rats and blocks estrogen-induced proliferation of human breast cancer cells in vitro, it is reasoned that decreased melatonin production leads to increased risk of breast cancer. To evaluate this hypothesis, the paper reviews epidemiological data on associations between electricity and breast cancer, and assesses the data on the effects of EMF exposure on melatonin physiology in both laboratory animals and humans. In addition, the results on the effects of melatonin on in vivo carcinogenesis in animals are detailed along with the controlled in vitro studies on melatonin's effects on human breast cancer cell lines. The literature is evaluated for strength of evidence, inter-relationships between various lines of evidence, and gaps in our knowledge. Based on the published data, it is currently unclear if EMF and electric light exposure are significant risk factors for breast cancer, but further study appears warranted. Given the ubiquitous nature of EMF and artificial light exposure along with the high incidence of breast cancer, even a small risk would have a substantial public health impact.
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Affiliation(s)
- G C Brainard
- Department of Neurology, Jefferson Medical College, Philadelphia, Pennsylvannia 19107, USA. george.brainardemail.tju.edu
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28
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Ram PT, Kiefer T, Silverman M, Song Y, Brown GM, Hill SM. Estrogen receptor transactivation in MCF-7 breast cancer cells by melatonin and growth factors. Mol Cell Endocrinol 1998; 141:53-64. [PMID: 9723886 DOI: 10.1016/s0303-7207(98)00095-1] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The pineal hormone, melatonin, inhibits proliferation of estrogen receptor (ER)-positive MCF-7 human breast cancer cells, modulates both ER mRNA and protein expression, and appears to be serum dependent, indicating interaction between melatonin and serum components. To examine the effects of melatonin on ER activity, ER transactivation assays were performed by transiently transfecting MCF-7 cells with an ERE-luciferase reporter construct. MCF-7 cells pre-treated with melatonin for as little as 5 min followed by either epidermal growth factor (EGF) or insulin resulted in the estrogen-independent transactivation of the ER. None of the compounds when used alone transactivated the ER. The ability of melatonin and EGF to transactivate the ER was abolished by the addition of the antiestrogen, ICI 164384, suggesting that melatonin and EGF co-operate to transactivate the ER. The modulation of ER transactivation was associated with changes in mitogen activated protein kinase activity and ER phosphorylation. This ER transactivation was blocked by pertussis toxin, a Galpha i-protein-coupled receptor inhibitor, suggesting cross talk between the G-protein-coupled melatonin receptor pathway and the EGF/insulin tyrosine kinase receptor pathways in modulating ER transactivation. Exactly how the ability of melatonin in combination with EGF to transactivate the ER relates to melatonin's observed growth suppressive effects is not clear. It is possible that, although melatonin and EGF transactivate the ER, this transactivation does not result in the full transcription of estrogen-responsive genes, but rather, makes the ER refractory to activation by estradiol, thus, blocking the mitogenic actions of estradiol.
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Affiliation(s)
- P T Ram
- Department of Anatomy, Tulane University School of Medicine, New Orleans, LA 70112, USA
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29
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Eck KM, Yuan L, Duffy L, Ram PT, Ayettey S, Chen I, Cohn CS, Reed JC, Hill SM. A sequential treatment regimen with melatonin and all-trans retinoic acid induces apoptosis in MCF-7 tumour cells. Br J Cancer 1998; 77:2129-37. [PMID: 9649124 PMCID: PMC2150391 DOI: 10.1038/bjc.1998.357] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Neoplastic events are marked by uncontrolled cell proliferation. One major focus of cancer research has been to identify treatments that reduce or inhibit cell growth. Over the years, various compounds, both naturally occurring and chemically synthesized, have been used to inhibit neoplastic cell proliferation. Two such oncostatic agents, melatonin and retinoic acid, have been shown to suppress the growth of hormone-responsive breast cancer. Currently, separate clinical protocols exist for the administration of retinoids and melatonin as adjuvant therapies for cancer. Using the oestrogen receptor (ER)-positive MCF-7 human breast tumour cell line, our laboratory has studied the effects of a sequential treatment regimen of melatonin followed by all-trans retinoic acid (atRA) on breast tumour cell proliferation in vitro. Incubation of hormonally responsive MCF-7 and T47D cells with melatonin (10(-9) M) followed 24 h later by atRA (10(-9) M) resulted in the complete cessation of cell growth as well as a reduction in the number of cells to below the initial plating density. This cytocidal effect is in contrast to the growth-suppressive effects seen with either hormone alone. This regimen of melatonin followed by atRA induced cytocidal effects on MCF-7 cells by activating pathways leading to apoptosis (programmed cell death) as evidenced by decreased ER and Bcl-2 and increased Bax and transforming growth factor beta 1 (TGF-beta1) expression. Apoptosis was reflected morphologically by an increase in the number of lysosomal bodies and perinuclear chromatin condensation, cytoplasmic blebbing and the presence of apoptotic bodies. The apoptotic effect of this sequential treatment with melatonin and atRA appears to be both cell and regimen specific as (a) ER-negative MDA-MB-231 and BT-20 breast tumour cells were unaffected, and (b) the simultaneous administration of melatonin and atRA was not associated with apoptosis in any of the breast cancer cell lines studied. Taken together, the results suggest that use of an appropriate regimen of melatonin and atRA should be considered for preclinical and clinical evaluation against ER-positive human breast cancer.
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MESH Headings
- Antineoplastic Combined Chemotherapy Protocols/pharmacology
- Apoptosis/drug effects
- Blotting, Northern
- Blotting, Western
- Breast Neoplasms/drug therapy
- Breast Neoplasms/metabolism
- Breast Neoplasms/pathology
- DNA, Neoplasm/analysis
- DNA, Neoplasm/isolation & purification
- Drug Administration Schedule
- Electrophoresis
- Humans
- Melatonin/administration & dosage
- Neoplasms, Hormone-Dependent/drug therapy
- Neoplasms, Hormone-Dependent/metabolism
- Neoplasms, Hormone-Dependent/pathology
- Proto-Oncogene Proteins/biosynthesis
- Proto-Oncogene Proteins c-bcl-2/biosynthesis
- Receptors, Estrogen/biosynthesis
- Receptors, Estrogen/drug effects
- Receptors, Estrogen/metabolism
- Transforming Growth Factor beta/biosynthesis
- Transforming Growth Factor beta/metabolism
- Tretinoin/administration & dosage
- Tumor Cells, Cultured
- bcl-2-Associated X Protein
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Affiliation(s)
- K M Eck
- Department of Anatomy, Tulane University School of Medicine, New Orleans, LA 70112, USA
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30
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Abstract
Exposure to power frequency electric and magnetic fields (EMF) is ubiquitous, and a body of epidemiologic studies has produced evidence suggestive of a possible link between EMF exposure and cancer of several types. This paper provides a perspective that holds key findings in the EMF literature against the background of important models and established principles in cancer biology. It is intended primarily for scientists whose expertise lies outside of cancer biology and animal bioassays. Current thinking holds that carcinogenesis is a multistep process that requires at least two genotoxic events in its critical path but that is facilitated by nongenotoxic proliferative effects on target cells. EMF, which itself is not believed to be genotoxic, could influence carcinogenesis if it exerted either direct or indirect effects on target cell turnover. Such effects could operate through receptor-mediated or nonreceptor-mediated pathways. However, effects relevant to carcinogenesis have not been confirmed, and a mode of action for EMF has not been determined. Chronic bioassays in rodents are in progress to examine the potential carcinogenicity of EMFs. EMF research has the opportunity to capitalize on the recent major advances in our understanding of carcinogenic processes.
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Affiliation(s)
- R Kavet
- Environment Group, Electric Power Research Institute, Palo Alto, CA 94303, USA
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31
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Molis TM, Spriggs LL, Jupiter Y, Hill SM. Melatonin modulation of estrogen-regulated proteins, growth factors, and proto-oncogenes in human breast cancer. J Pineal Res 1995; 18:93-103. [PMID: 7629697 DOI: 10.1111/j.1600-079x.1995.tb00146.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The growth-inhibitory actions of the pineal hormone, melatonin, on human breast tumor cells and the possible association between this inhibition and melatonin's down-regulation of the estrogen receptor (ER) expression were examined in the ER-positive, estrogen-responsive MCF-7 human breast tumor cell line. As previously reported, melatonin dramatically inhibits the growth of these breast tumor cells and down-regulates ER levels in these cells, suggesting that the modulation of ER may be an important mechanism by which melatonin inhibits breast cancer cell growth. In the present studies, Northern blot analysis was used to examine the expression of estrogen-regulated transcripts known to be involved in estrogen's mitogenic actions. Melatonin, at a physiologic concentration (10(-9) M), rapidly, significantly, and, in some cases, transiently elevated the steady-state mRNA levels of growth stimulatory products such as TGF alpha, c-myc, and pS2, which are normally up-regulated in response to estrogen. Conversely, melatonin decreased the expression of other factors normally up-regulated by estrogen, such as progesterone receptor and c-fos. Significant stimulation of the expression of the growth-inhibitory factor TGF beta was seen with melatonin treatment, potentially supporting the concept that melatonin's growth-inhibitory activity is mediated through the breast tumor cells' estrogen-response pathway. The early regulation of many of these products by melatonin suggests that mechanisms more rapid than the down-regulation of ER are important in melatonin's modulation of their expression. However, the long-term modulation of these transcripts (12-48 hr) may be heavily influenced by melatonin's down-regulation of ER expression. These results clearly define the need for additional in depth studies to dissect the cellular events leading to melatonin-induced growth inhibition in breast tumor cells.
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Affiliation(s)
- T M Molis
- Department of Anatomy, Tulane University School of Medicine, New Orleans, LA 70112, USA
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Waldhauser F, Ehrhart B, Förster E. Clinical aspects of the melatonin action: impact of development, aging, and puberty, involvement of melatonin in psychiatric disease and importance of neuroimmunoendocrine interactions. EXPERIENTIA 1993; 49:671-81. [PMID: 8359273 DOI: 10.1007/bf01923949] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
During the last decade we have learned much on physiological changes in the secretion of the pineal hormone melatonin (MLT) in man. Reportedly, there is little or no MLT secreted before age 3 months. Then MLT production commences, becomes circadian, and reaches highest nocturnal levels at the age of 1-3 years. During all of childhood nocturnal peak levels drop progressively by 80% until adult levels are reached. This alteration appears to be the consequence of increasing body size in face of constant MLT production during childhood. The biological significance of this MLT alteration is presently unknown. Because of conceptual considerations, major depressive syndrome (MDS) and seasonal affective disorder (SAD) have been in the focus of pineal research for several years. Although in these disorders alterations in MLT levels could not be substantiated, light therapy, a consequence of this research, was discovered as an effective treatment for SAD and perhaps for MDS. In addition, there is some recent evidence for low MLT levels in schizophrenia. Finally, the potential effect of MLT in neuroimmunoendocrine interactions is presently explored. Reportedly, in vitro studies and animal experiments give evidence for a modulatory role of MLT in the immune response. However, the exact way of this possible action of MLT remains to be clarified. Clinical studies are too scant for a meaningful estimation of MLT's involvement in human neuroimmunoendocrine interactions.
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Affiliation(s)
- F Waldhauser
- Department of Pediatrics, University of Vienna, Austria
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33
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Abstract
The in vitro antiproliferative action of pineal indoles on several tumor cell lines including melanoma (B16), sarcoma (S180), macrophage-like cell line (PU5), fibroblasts (3T3), and choriocarcinoma (JAr) was examined by measuring the incorporation of 3H-thymidine by the tumor cells, and, in the case of melanoma cells, by also measuring the incorporation of 3H-leucine and 3H-uridine. Uptake of crystal violet was used to assess the viability of the tumor cells. The order of inhibitory potency of the indoles was found to be methoxytryptamine > melatonin, methoxytryptophol, hydroxytryptophol, and methoxyindoleacetic acid > serotonin and hydroxyindoleacetic acid. The possibility of an adverse effect of the indoles on the viability of normal cells was also investigated by employing a primary culture of rat hepatocytes. The release of glutamate-oxaloacetate transaminase by hepatocytes was not affected by the indoles, although the release of glutamate-pyruvate transaminase was increased to a small extent and the uptake of crystal violet was slightly inhibited.
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Affiliation(s)
- S F Sze
- Department of Biochemistry, Faculty of Medicine, Chinese University of Hong Kong, Shatin, N.T
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Hill SM, Spriggs LL, Simon MA, Muraoka H, Blask DE. The growth inhibitory action of melatonin on human breast cancer cells is linked to the estrogen response system. Cancer Lett 1992; 64:249-56. [PMID: 1638517 DOI: 10.1016/0304-3835(92)90050-6] [Citation(s) in RCA: 110] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The pineal hormone, melatonin, was examined for its capacity to modulate the proliferation of a panel of human breast cancer cell lines. Melatonin inhibited, to a varying extent, the proliferation of all three estrogen-responsive cell lines, but had no effect on estrogen-insensitive breast tumor cell lines. Melatonin was also able to specifically block estrogen-induced proliferation in MCF-7 breast cancer cells. However, this action was abolished in the presence of tamoxifen. Therefore, it appears that the antiproliferative effects of melatonin are mediated through the estrogen-response pathway.
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Affiliation(s)
- S M Hill
- Tulane University, School of Medicine, Department of Anatomy, New Orleans, Louisiana 70112
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35
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Blask DE, Pelletier DB, Hill SM, Lemus-Wilson A, Grosso DS, Wilson ST, Wise ME. Pineal melatonin inhibition of tumor promotion in the N-nitroso-N-methylurea model of mammary carcinogenesis: potential involvement of antiestrogenic mechanisms in vivo. J Cancer Res Clin Oncol 1991; 117:526-32. [PMID: 1744157 DOI: 10.1007/bf01613283] [Citation(s) in RCA: 86] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The N-methyl-N-nitrosourea (NMU) model of hormone-responsive rat mammary carcinogenesis was used to address the hypothesis that melatonin (Mel), the principle hormone of the pineal gland, inhibits tumorigenesis by acting as an anti-promoting rather than an anti-initiating agent. Daily late-afternoon injections of Mel (500 micrograms/day), restricted to the initiation phase of NMU mammary tumorigenesis, were ineffective in altering tumor growth over a 20-week period. When Mel treatment was delayed for 4 weeks after NMU and then continued through the remainder of the promotion phase, only tumor number was significantly lower than in controls. However, when Mel injections encompassed the entire promotion phase, both tumor incidence and number were significantly lower than in the controls. Although elimination of the endogenous Mel signal via pinealectomy promoted tumor growth, the effect was not statistically significant. Serum levels of estradiol and tumor estrogen receptor content were unaltered by either Mel or pinealectomy. While Mel treatment failed to affect circulating prolactin levels, pinealectomy caused a two-fold increase in serum prolactin. The estradiol-stimulated recrudescence of tumors following ovariectomy was completely blocked by either 20, 100 or 500 micrograms Mel/day or tamoxifen (20 micrograms/day). Thus, Mel appears to be an anti-promoting hormone that may antagonize the tumor-promoting actions of estradiol in this model of mammary tumorigenesis.
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Affiliation(s)
- D E Blask
- Department of Anatomy, University of Arizona, Tucson 85724
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36
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Skene DJ, Bojkowski CJ, Currie JE, Wright J, Boulter PS, Arendt J. 6-sulphatoxymelatonin production in breast cancer patients. J Pineal Res 1990; 8:269-76. [PMID: 2380908 DOI: 10.1111/j.1600-079x.1990.tb00686.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The daily pattern of the major urinary metabolite of melatonin, 6-sulphatoxymelatonin (aMT6s), was determined in women prior to having a breast biopsy. Women with malignant tumors appeared to have significantly lower 24 h concentrations of aMT6s with a decrease in the amplitude of the rhythm compared to women with benign tumors. The amount of urinary aMT6s was dependent upon the age of the subject but was not affected by either menopausal status or body mass index. However, when the women with malignant tumors were compared with a large group of normal women of the same age their aMT6s levels were not outside the normal range. The results show that a large control group and very accurate age matching are essential when investigating melatonin production in different groups of subjects.
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Affiliation(s)
- D J Skene
- Department of Biochemistry, University of Surrey, England
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37
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Buzzell GR. Studies on the effects of the pineal hormone melatonin on an androgen-insensitive rat prostatic adenocarcinoma, the Dunning R 3327 HIF tumor. J Neural Transm (Vienna) 1988; 72:131-40. [PMID: 3385424 DOI: 10.1007/bf01250236] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The effects of the pineal indole melatonin on a transplantable androgen-insensitive fast-growing rat prostatic adenocarcinoma, the Dunning R 3327 HIF tumor, were examined. Afternoon injections of melatonin given to intact male rats enhanced tumor growth, while leading to a reduction in the weights of gonads and dorsal and ventral prostates. In anosmic hosts, this treatment had no effect on tumor growth or reproductive organ size. In castrated anosmic hosts, melatonin injections led to reductions in the growth of tumors, when compared with those in castrated hosts. Continuously available melatonin, in beeswax pellets, had no effect on growth of these tumors. These results are discussed in relation to the anticancer effects of melatonin and the effects of tumors on endogenous melatonin rhythms.
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Affiliation(s)
- G R Buzzell
- Department of Anatomy and Cell Biology, University of Alberta, Edmonton, Canada
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38
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Abstract
Injections of the pineal hormone melatonin reduced growth and increased doubling time of the R3327H Dunning prostatic adenocarcinoma in the Copenhagen X Fisher rat. This occurred even though testosterone levels (50% of normal) were ostensibly high enough to maintain normal tumor growth. Melatonin may act directly upon the conversion of testosterone to dihydrotestosterone to inhibit tumor growth. Alternatively, a more complicated mechanism may be involved since studies on MCF breast cancer tissue indicate an estrogen requirement for inhibition of growth by melatonin.
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Affiliation(s)
- R Philo
- Department of Neurobiology, University of Texas Medical School at Houston 77225
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