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Kahn M. Taking the road less traveled - the therapeutic potential of CBP/β-catenin antagonists. Expert Opin Ther Targets 2021; 25:701-719. [PMID: 34633266 PMCID: PMC8745629 DOI: 10.1080/14728222.2021.1992386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 10/08/2021] [Indexed: 10/20/2022]
Abstract
AREAS COVERED This perspective discusses the challenges of targeting the Wnt signaling cascade, the safety, efficacy, and therapeutic potential of specific CBP/β-catenin antagonists and a rationale for the pleiotropic effects of CBP/β-catenin antagonists beyond Wnt signaling. EXPERT OPINION CBP/β-catenin antagonists can correct lineage infidelity, enhance wound healing, both normal and aberrant (e.g. fibrosis) and force the differentiation and lineage commitment of stem cells and cancer stem cells by regulating enhancer and super-enhancer coactivator occupancy. Small molecule CBP/β-catenin antagonists rebalance the equilibrium between CBP/β-catenin versus p300/β-catenin dependent transcription and may be able to treat or prevent many diseases of aging, via maintenance of our somatic stem cell pool, and regulating mitochondrial function and metabolism involved in differentiation and immune cell function.
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Affiliation(s)
- Michael Kahn
- Department of Molecular Medicine, City of Hope, Beckman Research Institute, 1500 East Duarte Road Flower Building, Duarte, CA, USA
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Milesi MM, Varayoud J, Ramos JG, Luque EH. Uterine ERα epigenetic modifications are induced by the endocrine disruptor endosulfan in female rats with impaired fertility. Mol Cell Endocrinol 2017; 454:1-11. [PMID: 28559116 DOI: 10.1016/j.mce.2017.05.028] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 05/24/2017] [Accepted: 05/24/2017] [Indexed: 01/30/2023]
Abstract
High ERα activity may disrupt the window of uterine receptivity, causing defective implantation. We investigated whether implantation failures prompted by endosulfan are associated with aberrant ERα uterine expression and DNA methylation status during the pre-implantation period. ERα-dependent target genes that play a crucial role in the uterine receptivity for embryo attachment and implantation were also investigated. Newborn female rats received corn oil (vehicle, Control), 6 μg/kg/d of endosulfan (Endo6) or 600 μg/kg/d of endosulfan (Endo600) on postnatal days (PND) 1, 3, 5, and 7. On PND90, females were made pregnant and on gestational day 5 (GD5, pre-implantation period) uterine samples were collected. ERα expression was assessed at protein and mRNA levels by immunohistochemistry and real time RT-PCR, respectively. ERα transcript variants mRNA containing alternative 5'-untranslated regions (5'UTRs) were also evaluated. We searched for predicted transcription factors binding sites in ERα regulatory regions and assessed their methylation status by Methylation-Sensitive Restriction Enzymes-PCR technique (MSRE-PCR). The expression of the ERα-dependent uterine target genes, i.e. mucin-1 (MUC-1), insulin-like growth factor-1 (IGF-1), and leukemia inhibitory factor (LIF), was assessed by real time RT-PCR. Both doses of endosulfan increased the expression of ERα and its transcript variants ERα-OS, ERα-O, ERα-OT and ERα-E1. Moreover, a decreased DNA methylation levels were detected in some ERα regulatory regions, suggesting an epigenetic up-regulation of it transcription. ERα overexpression was associated with an induction of its downstream genes, MUC-1 and IGF-1, suggesting that endosulfan might alter the uterine estrogenic pathway compromising uterine receptivity. These alterations could account, at least in part, for the endosulfan-induced implantation failures.
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Affiliation(s)
- María M Milesi
- Instituto de Salud y Ambiente del Litoral (ISAL), Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Santa Fe, Argentina.
| | - Jorgelina Varayoud
- Instituto de Salud y Ambiente del Litoral (ISAL), Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Santa Fe, Argentina
| | - Jorge G Ramos
- Instituto de Salud y Ambiente del Litoral (ISAL), Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Santa Fe, Argentina
| | - Enrique H Luque
- Instituto de Salud y Ambiente del Litoral (ISAL), Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Santa Fe, Argentina
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3
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Weight-of-evidence evaluation of associations between particulate matter exposure and biomarkers of lung cancer. Regul Toxicol Pharmacol 2016; 82:53-93. [DOI: 10.1016/j.yrtph.2016.10.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 10/10/2016] [Accepted: 10/16/2016] [Indexed: 12/16/2022]
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4
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Miller AL, Geng C, Golovko G, Sharma M, Schwartz JR, Yan J, Sowers L, Widger WR, Fofanov Y, Vedeckis WV, Thompson EB. Epigenetic alteration by DNA-demethylating treatment restores apoptotic response to glucocorticoids in dexamethasone-resistant human malignant lymphoid cells. Cancer Cell Int 2014; 14:35. [PMID: 24795534 PMCID: PMC4008436 DOI: 10.1186/1475-2867-14-35] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Accepted: 04/01/2014] [Indexed: 11/17/2022] Open
Abstract
Background Glucocorticoids (GCs) are often included in the therapy of lymphoid malignancies because they kill several types of malignant lymphoid cells. GCs activate the glucocorticoid receptor (GR), to regulate a complex genetic network, culminating in apoptosis. Normal lymphoblasts and many lymphoid malignancies are sensitive to GC-driven apoptosis. Resistance to GCs can be a significant clinical problem, however, and correlates with resistance to several other major chemotherapeutic agents. Methods We analyzed the effect of treatment with the cytosine analogue 5 aza-2’ deoxycytidine (AZA) on GC resistance in two acute lymphoblastic leukemia (T or pre-T ALL) cell lines- CEM and Molt-4- and a (B-cell) myeloma cell line, RPMI 8226. Methods employed included tissue culture, flow cytometry, and assays for clonogenicity, cytosine extension, immunochemical identification of proteins, and gene transactivation. High throughput DNA sequencing was used to confirm DNA methylation status. Conclusions Treatment of these cells with AZA resulted in altered DNA methylation and restored GC-evoked apoptosis in all 3 cell lines. In CEM cells the altered epigenetic state resulted in site-specific phosphorylation of the GR, increased GR potency, and GC-driven induction of the GR from promoters that lie in CpG islands. In RPMI 8226 cells, expression of relevant coregulators of GR function was altered. Activation of p38 mitogen-activated protein kinase (MAPK), which is central to a feed-forward mechanism of site-specific GR phosphorylation and ultimately, apoptosis, occurred in all 3 cell lines. These data show that in certain malignant hematologic B- and T-cell types, epigenetically controlled GC resistance can be reversed by cell exposure to a compound that causes DNA demethylation. The results encourage studies of application to in vivo systems, looking towards eventual clinical applications.
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Affiliation(s)
- Aaron L Miller
- Department of Biochemistry & Molecular Biology, (ALM present address, Department. of Pediatrics, & Assay Devel. Service Division Galveston National Lab.), University of Texas Medical Branch, Galveston, TX, USA
| | - Chuandong Geng
- Department of Biochemistry & Molecular Biology, Louisiana State University Health Sciences Center, New Orleans, LA CG present address, Depts. of Medicine and of Molecular & Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Georgiy Golovko
- Department of Biology & Biochemistry, Centers for Biomedical & Environmental Genomics and/or Nuclear Receptors & Cell Signaling, University of Houston, Houston, TX, USA ; Department of Pharmacology & Toxicology, and Sealy Center for Structural Biology & Molecular Biophysics, Univ. of Texas Medical Branch, Galveston, TX, USA
| | - Meenakshi Sharma
- Department of Biology & Biochemistry, Centers for Biomedical & Environmental Genomics and/or Nuclear Receptors & Cell Signaling, University of Houston, Houston, TX, USA
| | - Jason R Schwartz
- Department of Biochemistry & Molecular Biology, Louisiana State University Health Sciences Center, New Orleans, LA CG present address, Depts. of Medicine and of Molecular & Cellular Biology, Baylor College of Medicine, Houston, TX, USA ; Present address St. Jude Children's Hospital, Memphis, TN, USA
| | - Jiabin Yan
- Department of Pharmacology & Toxicology, and Sealy Center for Structural Biology & Molecular Biophysics, Univ. of Texas Medical Branch, Galveston, TX, USA
| | - Lawrence Sowers
- Department of Pharmacology & Toxicology, and Sealy Center for Structural Biology & Molecular Biophysics, Univ. of Texas Medical Branch, Galveston, TX, USA
| | - William R Widger
- Department of Biology & Biochemistry, Centers for Biomedical & Environmental Genomics and/or Nuclear Receptors & Cell Signaling, University of Houston, Houston, TX, USA
| | - Yuriy Fofanov
- Department of Biology & Biochemistry, Centers for Biomedical & Environmental Genomics and/or Nuclear Receptors & Cell Signaling, University of Houston, Houston, TX, USA ; Department of Pharmacology & Toxicology, and Sealy Center for Structural Biology & Molecular Biophysics, Univ. of Texas Medical Branch, Galveston, TX, USA
| | - Wayne V Vedeckis
- Department of Biochemistry & Molecular Biology, Louisiana State University Health Sciences Center, New Orleans, LA CG present address, Depts. of Medicine and of Molecular & Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - E Brad Thompson
- Department of Biochemistry & Molecular Biology, (ALM present address, Department. of Pediatrics, & Assay Devel. Service Division Galveston National Lab.), University of Texas Medical Branch, Galveston, TX, USA ; Department of Biology & Biochemistry, Centers for Biomedical & Environmental Genomics and/or Nuclear Receptors & Cell Signaling, University of Houston, Houston, TX, USA
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Shilpa V, Bhagat R, Premalata CS, Pallavi VR, Ramesh G, Krishnamoorthy L. BRCA1 promoter hypermethylation and protein expression in ovarian carcinoma--an Indian study. Tumour Biol 2014; 35:4277-84. [PMID: 24385383 DOI: 10.1007/s13277-013-1558-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Accepted: 12/13/2013] [Indexed: 01/05/2023] Open
Abstract
Mounting evidences suggest that aberrant methylation of CpG islands is a major pathway leading to the inactivation of tumour suppressor genes and the development of cancer. The aim of the current study was to examine the prevalence of the promoter hypermethylation and protein expression of the BRCA1 gene in epithelial ovarian carcinoma (EOC) to understand the role of epigenetic silencing in ovarian carcinogenesis. We studied the promoter methylation of the BRCA1 gene by methylation-specific PCR in a cohort of 88 patients with EOC, 14 low malignant potential (LMP) tumours and 20 patients with benign tumours of the ovary. The expression of the BRCA1 protein by immunohistochemical analysis was carried out in a subset of 64 EOCs, 10 LMP tumours, 10 benign tumours and 5 normal ovarian tissues. The frequencies of methylation in EOCs and LMP tumours were 51.2 and 57%, respectively, significantly higher (p = 0.000 and p = 0.001) in comparison to benign tumours and normal ovarian tissue where no methylation was seen. Expression of BRCA1 was significantly lower in EOCs (p = 0.003). Lack of protein expression correlated with tumour grade and type. The methylation status correlated well with downregulation of BRCA1 expression. Our results clearly demonstrate that hypermethylation of BRCA1 promoter is a frequent event in ovarian cancer. These data support the hypothesis that BRCA1 promoter methylation plays an important role in the functional inactivation of BRCA1. Follow-up clinical data will reveal the impact of BRCA1 methylation on survival.
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Affiliation(s)
- V Shilpa
- Department of Biochemistry, Kidwai Memorial Institute of Oncology, Dr. M. H. Marigowda Road, Bangalore, 560029, India,
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6
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Estrogen receptor-alpha promoter methylation in sporadic basal-like breast cancer of Chinese women. Tumour Biol 2011; 32:713-9. [DOI: 10.1007/s13277-011-0172-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Accepted: 03/16/2011] [Indexed: 11/25/2022] Open
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Zhai Y, Bommer GT, Feng Y, Wiese AB, Fearon ER, Cho KR. Loss of estrogen receptor 1 enhances cervical cancer invasion. THE AMERICAN JOURNAL OF PATHOLOGY 2010; 177:884-95. [PMID: 20581058 DOI: 10.2353/ajpath.2010.091166] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
If left untreated, some cervical high-grade squamous intraepithelial lesions will progress to invasive squamous cell carcinoma (SCC), but the molecular events conferring invasive potential remain poorly defined. In prior work, we identified 48 genes that were down-regulated in SCCs compared with high-grade squamous intraepithelial lesions and normal squamous epithelia. In this study, a functional screening strategy was used to identify which of these genes regulate cervical cancer cell invasion. Two independent squamous epithelial cell lines were transduced with a library of short hairpin RNAs targeting the differentially expressed genes and tested for invasion of the chick chorioallantoic membrane. PCR was used to recover specific short hairpin RNAs from cells that invaded the chorioallantoic membrane. Constructs targeting estrogen receptor 1 (ESR1) were highly enriched in the invasive cells. The short hairpin RNA-mediated inhibition of ESR1 in SCC- and precancer-derived cell lines increased invasiveness in both in vivo and in vitro assays. Conversely, restoration of ESR1 expression in ESR1-negative cervical cancer cells reduced cell invasiveness. Loss of ESR1 expression was found to accompany cervical cancer progression in an analysis of primary normal cervix, low grade squamous intraepithelial lesions, high-grade squamous intraepithelial lesions, and SCC specimens. Molecular mechanisms underlying down-regulation of ESR1 in invasive cervical carcinomas appear to be complex and likely heterogeneous. Our findings indicate that loss of ESR1 has a major role in mediating cervical cancer invasion and progression.
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Affiliation(s)
- Yali Zhai
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109-2200, USA
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Balkwill GD, Derecka K, Garner TP, Hodgman C, Flint APF, Searle MS. Repression of translation of human estrogen receptor alpha by G-quadruplex formation. Biochemistry 2009; 48:11487-95. [PMID: 19860473 DOI: 10.1021/bi901420k] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Tissue-specific expression of the human estrogen receptor alpha gene (ESR1) is achieved through multiple promoter sequences resulting in various mRNA transcripts encoding a common protein but differing in their 5'-untranslated region (5'-UTR). Many cancers are estrogen-sensitive with neoplastic growth stimulated through the estrogen receptor, a transcription factor that regulates developmental genes. We demonstrate that the human ESR1 gene is rich in potential quadruplex-forming sequences with 3 of 20 identified within exonic regions. In particular, we show using CD, UV, and NMR spectroscopy that a stable DNA G-quadruplex motif is formed within the exon C gene sequence. This motif, which PCR shows is transcribed in normal and neoplastic endometrium and in MCF-7 cells, forms a stable RNA quadruplex demonstrable by CD and UV analysis. Cloning the exon C G-quadruplex sequence upstream of a luciferase reporter gene caused a 6-fold reduction of enzymatic activity compared to a mutant sequence. We conclude that the exon C G-quadruplex motif is present in the 5'-UTR of the mRNA transcript, where it modulates the efficiency of translation.
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Affiliation(s)
- Graham D Balkwill
- Centre for Biomolecular Sciences, School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK
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Asada H, Yamagata Y, Taketani T, Matsuoka A, Tamura H, Hattori N, Ohgane J, Hattori N, Shiota K, Sugino N. Potential link between estrogen receptor-alpha gene hypomethylation and uterine fibroid formation. Mol Hum Reprod 2008; 14:539-45. [PMID: 18701604 DOI: 10.1093/molehr/gan045] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Uterine leiomyomas are the most common uterine tumors in women. Estrogen receptor-alpha (ER-alpha) is more highly expressed in uterine leiomyomas than in normal myometrium, suggesting a link between uterine leiomyomas and ER-alpha expression. DNA methylation is an epigenetic mechanism of gene regulation and plays important roles in normal embryonic development and in disease progression including cancers. Here, we investigated the DNA methylation status of the ER-alpha promoter region (-1188 to +229 bp) in myometrium and leiomyoma. By sodium bisulfite sequencing, 49 CpG sites in the proximal promoter region of ER-alpha gene were shown to be unmethylated in both leiomyoma and normal myometrium. At seven CpG sites in the distal promoter region of the ER-alpha gene, there was a variation in DNA methylation status in myometrium and leiomyoma. Further analysis of the DNA methylation status by bisulfite restriction mapping among 11 paired samples of myometrium and leiomyoma indicated that CpG sites in the distal region of ER-alpha promoter are hypomethylated in leiomyomas of nine patients. In those patients, ER-alpha mRNA levels tended to be higher in the leiomyoma than in the myometrium. In conclusion, there was an aberrant DNA methylation status in the promoter region of ER-alpha gene in uterine leiomyoma, which may be associated with high ER-alpha mRNA expression.
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Affiliation(s)
- Hiromi Asada
- Department of Obstetrics and Gynecology, Yamaguchi University Graduate School of Medicine, Minamikogushi 1-1-1, Ube 755-8505, Japan
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10
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De-Castro Arce J, Göckel-Krzikalla E, Rösl F. Retinoic acid receptor beta silences human papillomavirus-18 oncogene expression by induction of de novo methylation and heterochromatinization of the viral control region. J Biol Chem 2007; 282:28520-28529. [PMID: 17686773 DOI: 10.1074/jbc.m702870200] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Retinoic acid receptor beta2 (RAR beta2) is often down-regulated during the multistep process to cervical cancer. In that way, its inhibitory function on the transcription factor AP-1, indispensable to maintain human papillomavirus (HPV) gene expression is relieved. Using HPV-18 positive HeLa cells as a model system, we show that ectopic expression of RAR beta2 is able to down-regulate HPV-18 transcription by selectively abrogating the binding of AP-1 to the viral regulatory region in a ligand-independent manner. This resulted in down-regulation of the viral mRNAs at the level of initiation of transcription. Decreased oncogene expression was accompanied by a re-induction of cell cycle inhibitory proteins such as p53, p21(CIP1), and p27(KIP) as well as by a cessation of cellular growth. Reduced transcriptional activity as a consequence of AP-1 reduction by selective c-Jun degradation apparently targets the HPV-18 regulatory region for epigenetic modification such as de novo methylation and nucleosomal condensation. This mechanism is otherwise counterbalanced by active and abundant viral transcription in malignant cells, because RAR beta2 itself becomes inactivated during cervical carcinogenesis. Hence, our study shows that the temporal co-existence of a potential repressor and viral oncoproteins is mutually exclusive and provides evidence of a cross-talk between a nuclear receptor, AP-1, and the epigenetic machinery.
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Affiliation(s)
- Johanna De-Castro Arce
- Angewandte Tumorvirologie, Abteilung Virale Transformationsmechanismen, Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 242, 69120 Heidelberg, Germany
| | - Elke Göckel-Krzikalla
- Angewandte Tumorvirologie, Abteilung Virale Transformationsmechanismen, Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 242, 69120 Heidelberg, Germany
| | - Frank Rösl
- Angewandte Tumorvirologie, Abteilung Virale Transformationsmechanismen, Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 242, 69120 Heidelberg, Germany.
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Caldwell JC, Keshava N. Key issues in the modes of action and effects of trichloroethylene metabolites for liver and kidney tumorigenesis. ENVIRONMENTAL HEALTH PERSPECTIVES 2006; 114:1457-63. [PMID: 16966105 PMCID: PMC1570066 DOI: 10.1289/ehp.8692] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Trichloroethylene (TCE) exposure has been associated with increased risk of liver and kidney cancer in both laboratory animal and epidemiologic studies. The U.S. Environmental Protection Agency 2001 draft TCE risk assessment concluded that it is difficult to determine which TCE metabolites may be responsible for these effects, the key events involved in their modes of action (MOAs) , and the relevance of these MOAs to humans. In this article, which is part of a mini-monograph on key issues in the health risk assessment of TCE, we present a review of recently published scientific literature examining the effects of TCE metabolites in the context of the preceding questions. Studies of the TCE metabolites dichloroacetic acid (DCA) , trichloroacetic acid (TCA) , and chloral hydrate suggest that both DCA and TCA are involved in TCE-induced liver tumorigenesis and that many DCA effects are consistent with conditions that increase the risk of liver cancer in humans. Studies of S-(1,2-dichlorovinyl) -l-cysteine have revealed a number of different possible cell signaling effects that may be related to kidney tumorigenesis at lower concentrations than those leading to cytotoxicity. Recent studies of trichloroethanol exploring an alternative hypothesis for kidney tumorigenesis have failed to establish the formation of formate as a key event for TCE-induced kidney tumors. Overall, although MOAs and key events for TCE-induced liver and kidney tumors have yet to be definitively established, these results support the likelihood that toxicity is due to multiple metabolites through several MOAs, none of which appear to be irrelevant to humans.
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Affiliation(s)
- Jane C Caldwell
- National Center for Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Washington, DC, USA.
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Wiley A, Katsaros D, Chen H, Rigault de la Longrais IA, Beeghly A, Puopolo M, Singal R, Zhang Y, Amoako A, Zelterman D, Yu H. Aberrant promoter methylation of multiple genes in malignant ovarian tumors and in ovarian tumors with low malignant potential. Cancer 2006; 107:299-308. [PMID: 16773633 DOI: 10.1002/cncr.21992] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND Methylation-mediated suppression of detoxification, DNA repair, and tumor suppressor genes has been implicated in cancer development and progression. Studies also have indicated that concordant methylation of multiple genes (methylator phenotypes), rather than a single gene, may predict cancer prognosis. The current study was designed to determine whether a methylator phenotype exists in ovarian cancer, whether methylation frequencies differ between malignant ovarian tumors and ovarian tumors with low malignant potential (LMP or borderline), and whether methylation of multiple genes affects patient survival. METHODS The current study included 234 consecutively diagnosed patients with either LMP (n = 19 patients) or malignant (n = 215 patients) ovarian tumors. DNA samples were extracted from fresh frozen tissues and were analyzed for methylation in the promoter region of 6 genes (p16, breast cancer 1 [BRCA1], insulin-like growth factor-binding protein 3 [IGFBP-3], glutathione S-transferase pi 1 [GSTP1], estrogen receptor-alpha [ER-alpha], and human MutL homologue 1 [hMLH1]) by using methylation-specific polymerase chain reaction analysis. RESULTS The frequencies of methylation in malignant tumors and LMP tumors were 0% and 0% for GSTP1, respectively; 9% and 0% for hMLH1, respectively; 21% and 5% for BRCA1, respectively; 42% and 21% for p16, respectively; 44% and 26% for IGFBP-3, respectively; and 57% and 42% for ER-alpha, respectively. A methylator phenotype was not detected, but a calculated methylation index (MI) that was based on the total number of genes methylated in each tumor was associated with ovarian cancer risk and progression. A higher MI was associated with malignant tumors (odds ratio, 10.11; 95% confidence interval [95% CI], 1.19-85.75) and disease progression (hazards ratio, 6.53; 95% CI, 1.39-30.65). CONCLUSIONS Although a methylator phenotype was not identified, the current results suggested that methylation of multiple genes may play an important role in ovarian cancer development and progression and may have clinical implications in prognosis.
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Affiliation(s)
- Andrew Wiley
- Department of Epidemiology and Public Health, Yale Cancer Center, Yale University School of Medicine, New Haven, Connecticut 06520-8034, USA
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Kang SC, Lee BM. DNA methylation of estrogen receptor alpha gene by phthalates. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2005; 68:1995-2003. [PMID: 16326419 DOI: 10.1080/15287390491008913] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The phthalates are ubiquitous industrial plasticizers and include agents such as di(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), and butyl benzyl phthalate (BBP), which are classified as endocrine disruptors because of their anti-androgenic or pro-estrogenic effects. A recent study suggested that DBP produced the hypomethylation of c-myc protooncogene in mouse liver to activate c-myc. In the present study, DNA hypomethylation at the promoter region of the estrogen receptor alpha (ERalpha) gene was investigated by methylation-specific polymerase chain reaction (MSP) in a human breast cancer (MCF7) and in a normal (MCF10A) cell line after DBP treatment. Yeast-based estrogen receptor transcription assays showed that hERalpha gene expression was induced by BBP but not DBP. Moreover, MCF7 cells treated with BBP or DBP at 10(-5)M led to the demethylation of ERalpha promoter-associated CpG islands. These data suggest that an altered ER mRNA expression by BBP might be related to aberrant DNA methylation in the promoter region of ERalpha.
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Affiliation(s)
- Se Chan Kang
- Division of Toxicology, School of Pharmacy, SungKyunKwan University, Jangan-Gu, Suwon, Kyonggi-do, Korea
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Schneider-Stock R, Roessner A, Ullrich O. Methyltransferases in apoptosis and cancer. ACTA ACUST UNITED AC 2005. [DOI: 10.1002/sita.200400047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Plísková M, Vondrácek J, Kren V, Gazák R, Sedmera P, Walterová D, Psotová J, Simánek V, Machala M. Effects of silymarin flavonolignans and synthetic silybin derivatives on estrogen and aryl hydrocarbon receptor activation. Toxicology 2005; 215:80-9. [PMID: 16076518 DOI: 10.1016/j.tox.2005.06.020] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2005] [Revised: 06/13/2005] [Accepted: 06/23/2005] [Indexed: 10/25/2022]
Abstract
Silymarin, a standardized mixture of flavonolignans, or its major constituents could be effective for prevention and treatment of hepatic damage or skin cancer. However, their potential side effects, such as modulation of endocrine functions via the disruption of estrogen receptor (ER) and/or aryl hydrocarbon receptor (AhR) activation, are largely unknown. In the present study, we investigated impact of silymarin, its constituents and a series of their synthetic derivatives on ER- and AhR-mediated activities using in vitro reporter gene assays. We found that none of the compounds under study affected the AhR-mediated activity in rat hepatoma cells. Contrary to that, several compounds behaved as either partial or full ER agonists. Silymarin elicited partial ER activation, with silybin B being probably responsible for a majority of the weak ER-mediated activity of silymarin; silybin A and other flavonolignans were found to be inactive and potent ER agonist taxifolin is only a minor constituent of silymarin. To our knowledge, this is probably the first time, when receptor-specific in vitro effects of separated diastereomers have been demonstrated. In contrast to silymarin constituents, the synthetic silybin derivatives, potentially useful as chemoprotective agents, did not modulate the ER-mediated activity, with exception of 23-O-pivaloylsilybin. Interestingly, 7-O-benzylsilybin potentiated ER-mediated activity of 17beta-estradiol despite possessing no estrogenic activity. In conclusion, our data suggest that estrogenicity of some silymarin constituents should be taken in account as their potential side effect when considered as chemopreventive compounds. These results also stress the need to study biological activities of purified or synthesized diastereomers of silybin derivatives.
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Balfe PJ, McCann AH, Welch HM, Kerin MJ. Estrogen receptor beta and breast cancer. EUROPEAN JOURNAL OF SURGICAL ONCOLOGY 2004; 30:1043-50. [PMID: 15522549 DOI: 10.1016/j.ejso.2004.06.019] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/25/2004] [Indexed: 11/15/2022]
Abstract
A second estrogen receptor, estrogen receptor-beta, was identified in 1996 and has led to an intensive re-evaluation of the role of estrogens in normal physiological and disease processes. While much has been learnt about this new receptor, there remain many outstanding questions, particularly regarding its prognostic significance and therapeutic implications.
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Affiliation(s)
- P J Balfe
- Department of Surgery and BreastCheck, Mater Misericordiae University Hospital, Eccles St., Dublin 7, Ireland.
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Klopper JP, Hays WR, Sharma V, Baumbusch MA, Hershman JM, Haugen BR. Retinoid X receptor-γ and peroxisome proliferator-activated receptor-γ expression predicts thyroid carcinoma cell response to retinoid and thiazolidinedione treatment. Mol Cancer Ther 2004. [DOI: 10.1158/1535-7163.1011.3.8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Poorly differentiated, metastatic thyroid cancer is difficult to treat. These tumors often do not concentrate radioactive iodine and may require chemotherapy, which is suboptimal and toxic. Nuclear hormone receptors peroxisome proliferator-activated receptor γ (PPARγ) and retinoid X receptor (RXR) are variably expressed in thyroid carcinoma cell lines. Expression of these receptors may predict thyroid cancer cell response to treatment with rexinoids and thiazolidinediones. We studied three thyroid carcinoma cell lines: BHP 5-16 (PPARγ−/RXRγ+), BHP 2-7 (PPARγ±/RXRγ−), and DRO-90 (RXRγ+/PPARγ+). BHP 5-16 (RXRγ+) cells treated with rexinoid had decreased proliferation to 69 ± 6% growth compared with vehicle. BHP 2-7 (PPARγ+) cells treated with thiazolidinedione had no decrease in cellular proliferation. DRO-90 (RXRγ+ and PPARγ+) cells had 36 ± 10%, 15 ± 3%, and 13 ± 4% growth when treated with rexinoid, thiazolidinedione, or a combination, respectively. We next investigated the role of apoptosis in the ligand-responsive BHP 5-16 and DRO-90 cells. BHP 5-16 cells underwent no significant apoptosis with rexinoid (1 μmol/L). DRO-90 cells, however, had 3.6 ± 1.3% apoptotic cells with vehicle, 13 ± 3.5% with rexinoid (1 μmol/L), 18 ± 4% with thiazolidinedione (1 μmol/L), and 28 ± 6% with combination treatment (1 μmol/L), suggesting that apoptosis plays a major role in this anaplastic cell line and that the effects of the two ligands are additive. We conclude that receptor expression is necessary for inhibition of thyroid carcinoma growth with ligand treatment but may not be sufficient for response. Additionally, expression of both RXRγ and PPARγ may be necessary for maximal growth inhibition by ligands and may be required for the increased apoptosis.
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Affiliation(s)
- Joshua P. Klopper
- 1Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado Cancer Center, University of Colorado Health Sciences Center, Denver, Colorado and
| | - William R. Hays
- 1Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado Cancer Center, University of Colorado Health Sciences Center, Denver, Colorado and
| | - Vibha Sharma
- 1Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado Cancer Center, University of Colorado Health Sciences Center, Denver, Colorado and
| | - Margaret A. Baumbusch
- 1Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado Cancer Center, University of Colorado Health Sciences Center, Denver, Colorado and
| | - Jerome M. Hershman
- 2Department of Medicine, West Los Angeles VAMC and University of California School of Medicine, Los Angeles, California
| | - Bryan R. Haugen
- 1Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado Cancer Center, University of Colorado Health Sciences Center, Denver, Colorado and
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Penolazzi L, Lambertini E, Giordano S, Sollazzo V, Traina G, del Senno L, Piva R. Methylation analysis of the promoter F of estrogen receptor alpha gene: effects on the level of transcription on human osteoblastic cells. J Steroid Biochem Mol Biol 2004; 91:1-9. [PMID: 15261302 DOI: 10.1016/j.jsbmb.2004.02.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2003] [Accepted: 02/02/2004] [Indexed: 01/09/2023]
Abstract
In this study, the methylation status of the distal promoter F of estrogen receptor alfa (ERalpha) gene in human osteoblastic cells was investigated. The activity of this promoter is responsible for the ERalpha gene transcription in bone tissue. The methylation status of promoter F was here evaluated, for the first time, by direct sequencing of bisulfite-treated genomic DNA, at 10 CpG specific sites localized in a region of about 800 bp. An heterogeneous methylation pattern was observed. The most notable difference was found at four particular CpGs, distant from the exon F transcription start site, showing a methylation status that correlates with the expression level, being ERalpha mRNA transcription reduced in a partially methylated cells but preserved in demethylated cells. The other CpG sites, localized around the transcription start site, were always demethylated except for MG-63 cells showing the lowest level of ERalpha expression. By quantitative RT-PCR analysis we demonstrated that ERalpha gene expression was higher in primary osteoblasts than in bone-derived cells (MG-63 and SaOS-2) and in all cases the ERalpha mRNA is represented by the isoform F. The same 10 CpG sites were investigated in non-osseous cell lines and were found fully methylated in ERalpha-negative breast cancer cells (MDA-MB-231) and completely demethylated in ERalpha-positive breast cancer cells (MCF7). The overall results suggest that methylation of the CpG sites inside ERalpha gene promoter F here analyzed may contribute to ERalpha transcriptional control, directly or indirectly, influencing the tissue specific expression of the gene.
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Affiliation(s)
- Letizia Penolazzi
- Dipartimento di Biochimica e Biologia Molecolare, Università degli Studi di Ferrara, Via L. Borsari, 46 44100, Italy
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Maruvada P, Dmitrieva NI, East-Palmer J, Yen PM. Cell cycle-dependent expression of thyroid hormone receptor-beta is a mechanism for variable hormone sensitivity. Mol Biol Cell 2004; 15:1895-903. [PMID: 14767065 PMCID: PMC379285 DOI: 10.1091/mbc.e03-09-0636] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Thyroid hormone receptors (TRs) are ligand-regulatable transcription factors. Currently, little is known about the expression of TRs or other nuclear hormone receptors during the cell cycle. We thus developed a stable expression system to express green fluorescent protein-TRbeta in HeLa cells under tetracycline regulation, and studied TR expression during the cell cycle by laser scanning cytometry. Only approximately 9-15% of the nonsynchronized cell population expressed TR because the majority of cells were in G(1) phase and did not express detectable amounts of TR. However, when cells were synchronized in early S phase with hydroxyurea and then released, TR expression levels increased in a cell cycle-dependent manner and peaked to 30-40% cells expressing TR at late G(2)/M phase before declining to nonsynchronized levels. Moreover, we observed a direct correlation between transcriptional activity and TR expression during the cell cycle. Similar cell cycle-dependent findings also were observed for endogenous TR in rat pituitary GH(3) cells. Last, cycloheximide studies demonstrated that the increase in TR expression was primarily due to increased translation. These novel observations of cell cycle-dependent expression of TR suggest that differential hormone sensitivity can occur during the cell cycle and may contribute to cell cycle progression during normal development and oncogenesis.
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Affiliation(s)
- Padma Maruvada
- Molecular Regulation and Neuroendocrinology Section, Clinical Endocrinology Branch, National Institute of Diabetes, Digestive, and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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Mills K. Methods for the molecular analysis of cancer. An overview. Mol Biotechnol 2003; 23:167-70. [PMID: 12632699 DOI: 10.1385/mb:23:2:167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Cancer arises as a result of complex and interacting abnormalities. However, over the past 20-25 yr numerous technological advances in molecular biology have led to a dramatic increase in the identification of the molecular processes involved in the development of cancers. The analysis of these molecular changes can be done on different levels: at the DNA or RNA level, or by assessment of posttranscriptional events. This overview discusses the merits of different methods for the analysis of DNA such as SSCP or DGCE. The exciting methods of RNA expression analysis using oligo or cDNA gene chips are also discussed. The importance of methods to analyze posttranscriptional or the effect that altered telomerase activity or methylation status contributes to the phenotype of the cancer cell is emphasized. These techniques will contribute to a better understanding of cancer initiation and progression and will eventually lead toward the development of new molecular-targeted drug therapies.
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Affiliation(s)
- Ken Mills
- Department of Haematology, University of Wales College of Medicine, Heath Park, Cardiff, CF14 4XN. millski@
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