101
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Feed-forward transcriptional programming by nuclear receptors: regulatory principles and therapeutic implications. Pharmacol Ther 2014; 145:85-91. [PMID: 25168919 DOI: 10.1016/j.pharmthera.2014.08.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 08/19/2014] [Indexed: 01/22/2023]
Abstract
Nuclear receptors (NRs) are widely targeted to treat a range of human diseases. Feed-forward loops are an ancient mechanism through which single cell organisms organize transcriptional programming and modulate gene expression dynamics, but they have not been systematically studied as a regulatory paradigm for NR-mediated transcriptional responses. Here, we provide an overview of the basic properties of feed-forward loops as predicted by mathematical models and validated experimentally in single cell organisms. We review existing evidence implicating feed-forward loops as important in controlling clinically relevant transcriptional responses to estrogens, progestins, and glucocorticoids, among other NR ligands. We propose that feed-forward transcriptional circuits are a major mechanism through which NRs integrate signals, exert temporal control over gene regulation, and compartmentalize client transcriptomes into discrete subunits. Implications for the design and function of novel selective NR ligands are discussed.
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102
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Estradiol promotes pentose phosphate pathway addiction and cell survival via reactivation of Akt in mTORC1 hyperactive cells. Cell Death Dis 2014; 5:e1231. [PMID: 24832603 PMCID: PMC4047866 DOI: 10.1038/cddis.2014.204] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2014] [Revised: 03/26/2014] [Accepted: 04/08/2014] [Indexed: 01/01/2023]
Abstract
Lymphangioleiomyomatosis (LAM) is a female-predominant interstitial lung disease that can lead to respiratory failure. LAM cells typically have inactivating TSC2 mutations, leading to mTORC1 activation. The gender specificity of LAM suggests that estradiol contributes to disease development, yet the underlying pathogenic mechanisms are not completely understood. Using metabolomic profiling, we identified an estradiol-enhanced pentose phosphate pathway signature in Tsc2-deficient cells. Estradiol increased levels of cellular NADPH, decreased levels of reactive oxygen species, and enhanced cell survival under oxidative stress. Mechanistically, estradiol reactivated Akt in TSC2-deficient cells in vitro and in vivo, induced membrane translocation of glucose transporters (GLUT1 or GLUT4), and increased glucose uptake in an Akt-dependent manner. (18)F-FDG-PET imaging demonstrated enhanced glucose uptake in xenograft tumors of Tsc2-deficient cells from estradiol-treated mice. Expression array study identified estradiol-enhanced transcript levels of glucose-6-phosphate dehydrogenase (G6PD), the rate-limiting enzyme of the pentose phosphate pathway. Consistent with this, G6PD was abundant in xenograft tumors and lung metastatic lesions of Tsc2-deficient cells from estradiol-treated mice. Molecular depletion of G6PD attenuated estradiol-enhanced survival in vitro, and treatment with 6-aminonicotinamide, a competitive inhibitor of G6PD, reduced lung colonization of Tsc2-deficient cells. Collectively, these data indicate that estradiol promotes glucose metabolism in mTORC1 hyperactive cells through the pentose phosphate pathway via Akt reactivation and G6PD upregulation, thereby enhancing cell survival under oxidative stress. Interestingly, a strong correlation between estrogen exposure and G6PD was also found in breast cancer cells. Targeting the pentose phosphate pathway may have therapeutic benefit for LAM and possibly other hormonally dependent neoplasms.
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103
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Genome-wide activity of unliganded estrogen receptor-α in breast cancer cells. Proc Natl Acad Sci U S A 2014; 111:4892-7. [PMID: 24639548 DOI: 10.1073/pnas.1315445111] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Estrogen receptor-α (ERα) has central role in hormone-dependent breast cancer and its ligand-induced functions have been extensively characterized. However, evidence exists that ERα has functions that are independent of ligands. In the present work, we investigated the binding of ERα to chromatin in the absence of ligands and its functions on gene regulation. We demonstrated that in MCF7 breast cancer cells unliganded ERα binds to more than 4,000 chromatin sites. Unexpectedly, although almost entirely comprised in the larger group of estrogen-induced binding sites, we found that unliganded-ERα binding is specifically linked to genes with developmental functions, compared with estrogen-induced binding. Moreover, we found that siRNA-mediated down-regulation of ERα in absence of estrogen is accompanied by changes in the expression levels of hundreds of coding and noncoding RNAs. Down-regulated mRNAs showed enrichment in genes related to epithelial cell growth and development. Stable ERα down-regulation using shRNA, which caused cell growth arrest, was accompanied by increased H3K27me3 at ERα binding sites. Finally, we found that FOXA1 and AP2γ binding to several sites is decreased upon ERα silencing, suggesting that unliganded ERα participates, together with other factors, in the maintenance of the luminal-specific cistrome in breast cancer cells.
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104
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Meng G, Vingron M. Condition-specific target prediction from motifs and expression. ACTA ACUST UNITED AC 2014; 30:1643-50. [PMID: 24532727 DOI: 10.1093/bioinformatics/btu066] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
MOTIVATION It is commonplace to predict targets of transcription factors (TFs) by sequence matching with their binding motifs. However, this ignores the particular condition of the cells. Gene expression data can provide condition-specific information, as is, e.g. exploited in Motif Enrichment Analysis. RESULTS Here, we introduce a novel tool named condition-specific target prediction (CSTP) to predict condition-specific targets for TFs from expression data measured by either microarray or RNA-seq. Based on the philosophy of guilt by association, CSTP infers the regulators of each studied gene by recovering the regulators of its co-expressed genes. In contrast to the currently used methods, CSTP does not insist on binding sites of TFs in the promoter of the target genes. CSTP was applied to three independent biological processes for evaluation purposes. By analyzing the predictions for the same TF in three biological processes, we confirm that predictions with CSTP are condition-specific. Predictions were further compared with true TF binding sites as determined by ChIP-seq/chip. We find that CSTP predictions overlap with true binding sites to a degree comparable with motif-based predictions, although the two target sets do not coincide. AVAILABILITY AND IMPLEMENTATION CSTP is available via a web-based interface at http://cstp.molgen.mpg.de.
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Affiliation(s)
- Guofeng Meng
- Department of Computational Molecular Biology, Max Planck Institute for Molecular Genetics, Ihnestrasse 73, 14195 Berlin, Germany
| | - Martin Vingron
- Department of Computational Molecular Biology, Max Planck Institute for Molecular Genetics, Ihnestrasse 73, 14195 Berlin, Germany
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105
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Szatmary AC, Stuelten CH, Nossal R. Improving the design of the agarose spot assay for eukaryotic cell chemotaxis. RSC Adv 2014; 4:57343-57349. [PMID: 25530845 DOI: 10.1039/c4ra08572h] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Migration of cells along gradients of effector molecules, i.e., chemotaxis, is necessary in immune response and is involved in development and cancer metastasis. The experimental assessment of chemotaxis thus is of high interest. The agarose spot assay is a simple tissue culture system used to analyze chemotaxis. Although direction sensing requires gradients to be sufficiently steep, how the chemical gradients developed in this assay change over time, and thus, under what conditions chemotaxis is plausible, has not yet been determined. Here, we use numerical solution of the diffusion equation to determine the chemoattractant gradient produced in the assay. Our analysis shows that, for the usual spot size, the lifetime of the assay is optimized if the chemoattractant concentration in the spot is initially 30 times the dissociation constant of the chemoattractant-receptor bond. This result holds regardless of the properties of the chemoattractant. With this initial concentration, the chemoattractant gradient falls to the minimum threshold for directional sensing at the same time that the concentration drops to the optimal level for detecting gradient direction. If a higher initial chemoattractant concentration is used, the useful lifetime of the assay is likely to be shortened because receptor saturation may decrease the cells' sensitivity to the gradient; lower initial concentrations would result in too little chemoattractant for the cells to detect. Moreover, chemoattractants with higher diffusion coefficients would sustain gradients for less time. Based on previous measurements of the diffusion coefficients of the chemoattractants EGF and CXCL12, we estimate that the assay will produce gradients that cells can sense for a duration of 10 h for EGF and 5 h for CXCL12. These gradient durations are comparable to what can be achieved with the Boyden chamber assay. The analysis presented in this work facilitates determination of suitable parameters for the assay, and can be used to assess whether observed cell motility is likely due to chemotaxis or chemokinesis.
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Affiliation(s)
- Alex C Szatmary
- Program in Physical Biology, Eunice Kennedy Shriver National Institute of Child Health, and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Christina H Stuelten
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Ralph Nossal
- Program in Physical Biology, Eunice Kennedy Shriver National Institute of Child Health, and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
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106
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Al-Mulla F, Bitar MS, Thiery JP, Zea TT, Chatterjee D, Bennett L, Park S, Edwards J, Yeung KC. Clinical implications for loss or diminution of expression of Raf-1 kinase inhibitory protein and its phosphorylated form in ductal breast cancer. Am J Cancer Res 2013; 3:446-464. [PMID: 24224123 PMCID: PMC3816965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2013] [Accepted: 10/11/2013] [Indexed: 06/02/2023] Open
Abstract
Raf Kinase inhibitory protein (RKIP) is a well-established metastasis suppressor that is frequently downregulated in aggressive cancers. The impact of RKIP and its phosphorylated form on disease-free survival (DFS) and other clinicopathological parameters in breast cancer is yet to be discovered. To this end, we examined RKIP expression in 3 independent breast cancer cohorts. At the Protein level, loss or reduced total RKIP expression was associated with large-sized tumors characterized by high proliferative index, high-grade and diminished estrogen (ER) and progesterone receptor expression. Loss or diminution of RKIP expression was significantly associated with shorter DFS in all cohorts. Moreover, the complete loss of p-RKIP was an independent prognostic factor using multivariate analysis in operable invasive ductal breast cancer. We show for the first time that ER, partly, drives RKIP expression through MTA3-Snail axis. Consistent with this finding, we found that, at the mRNA level, RKIP expression varied significantly across the different molecular subtypes of breast cancer with the Luminal (ER+) subtype expressing high levels of RKIP and the more aggressive Claudin-low (ER-) subtype, which depicted the highest epithelial to mesenchymal transition (EMT) registered the lowest RKIP expression levels. In conclusion, loss of expression/diminution of RKIP or its phosphorylated form is associated with poor diseases-free survival in breast cancer. Determining the expression of RKIP and p-RKIP adds significant prognostic value to the management and subtyping of this disease.
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Affiliation(s)
- Fahd Al-Mulla
- Department of Pathology, Molecular Pathology Unit, Faculty of Medicine, Kuwait University, Health Sciences CentreSafat, Kuwait
| | - Milad S Bitar
- Department of Pharmacology, Faculty of Medicine, Kuwait University, Health Sciences CentreSafat, Kuwait
| | - Jean Paul Thiery
- Department of Biochemistry, National University of Singapore#02-03, MD7, 8 Medical Drive, Singapore, 117597
| | - Tan Tuan Zea
- Department of Biochemistry, National University of Singapore#02-03, MD7, 8 Medical Drive, Singapore, 117597
| | - Devasis Chatterjee
- Department of Medicine, Rhode Island Hospital and The Alpert Medical School of Brown UniversityProvidence, RI, USA
| | - Lindsay Bennett
- Institute of Cancer, MVLS, McGregor Building, University of GlasgowGlasgow, U.K. G128QQ
| | - Sungdae Park
- Department of Biochemistry and Cancer Biology, College of Medicine, Health Science Campus, University of ToledoToledo, Ohio, USA
| | - Joanne Edwards
- Institute of Cancer, MVLS, McGregor Building, University of GlasgowGlasgow, U.K. G128QQ
| | - Kam C Yeung
- Department of Biochemistry and Cancer Biology, College of Medicine, Health Science Campus, University of ToledoToledo, Ohio, USA
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107
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Wu X, Li Y, Wang J, Wen X, Marcus MT, Daniels G, Zhang DY, Ye F, Wang LH, Du X, Adams S, Singh B, Zavadil J, Lee P, Monaco ME. Long chain fatty Acyl-CoA synthetase 4 is a biomarker for and mediator of hormone resistance in human breast cancer. PLoS One 2013; 8:e77060. [PMID: 24155918 PMCID: PMC3796543 DOI: 10.1371/journal.pone.0077060] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Accepted: 09/05/2013] [Indexed: 12/16/2022] Open
Abstract
The purpose of this study was to determine the role of long-chain fatty acyl-CoA synthetase 4 (ACSL4) in breast cancer. Public databases were utilized to analyze the relationship between ACSL4 mRNA expression and the presence of steroid hormone and human epidermal growth factor receptor 2 (HER2) in both breast cancer cell lines and tissue samples. In addition, cell lines were utilized to assess the consequences of either increased or decreased levels of ACSL4 expression. Proliferation, migration, anchorage-independent growth and apoptosis were used as biological end points. Effects on mRNA expression and signal transduction pathways were also monitored. A meta-analysis of public gene expression databases indicated that ACSL4 expression is positively correlated with a unique subtype of triple negative breast cancer (TNBC), characterized by the absence of androgen receptor (AR) and therefore referred to as quadruple negative breast cancer (QNBC). Results of experiments in breast cancer cell lines suggest that simultaneous expression of ACSL4 and a receptor is associated with hormone resistance. Forced expression of ACSL4 in ACSL4-negative, estrogen receptor α (ER)-positive MCF-7 cells resulted in increased growth, invasion and anchorage independent growth, as well as a loss of dependence on estrogen that was accompanied by a reduction in the levels of steroid hormone receptors. Sensitivity to tamoxifen, triacsin C and etoposide was also attenuated. Similarly, when HER2-positive, ACSL4-negative, SKBr3 breast cancer cells were induced to express ACSL4, the proliferation rate increased and the apoptotic effect of lapatinib was reduced. The growth stimulatory effect of ACSL4 expression was also observed in vivo in nude mice when MCF-7 control and ACSL4-expressing cells were utilized to induce tumors. Our data strongly suggest that ACSL4 can serve as both a biomarker for, and mediator of, an aggressive breast cancer phenotype.
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MESH Headings
- Animals
- Antineoplastic Agents/pharmacology
- Antineoplastic Agents/therapeutic use
- Apoptosis/drug effects
- Apoptosis/genetics
- Biomarkers, Tumor/genetics
- Biomarkers, Tumor/metabolism
- Breast Neoplasms/classification
- Breast Neoplasms/drug therapy
- Breast Neoplasms/enzymology
- Breast Neoplasms/genetics
- Cell Adhesion
- Cell Line, Tumor
- Cell Proliferation
- Coenzyme A Ligases/genetics
- Coenzyme A Ligases/metabolism
- Drug Resistance, Neoplasm/drug effects
- Drug Resistance, Neoplasm/genetics
- Estrogen Receptor alpha/genetics
- Estrogen Receptor alpha/metabolism
- Female
- Gene Expression Profiling
- Gene Expression Regulation, Neoplastic/drug effects
- Hormones/pharmacology
- Humans
- Mice
- Mice, Nude
- Neoplasm Invasiveness
- Oligonucleotide Array Sequence Analysis
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptor, ErbB-2/genetics
- Receptor, ErbB-2/metabolism
- Reproducibility of Results
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Affiliation(s)
- Xinyu Wu
- Department of Neuroscience & Physiology, New York University School of Medicine, New York, New York, United States of America
| | - Yirong Li
- Department of Pathology, New York University School of Medicine, New York, New York, United States of America
| | - Jinhua Wang
- Department of Pediatrics, New York University School of Medicine, New York, New York, United States of America
- NYU Cancer Institute, New York University School of Medicine, New York, New York, United States of America
- NYU Center for Health Informatics and Bioinformatics, New York University School of Medicine, New York, New York, United States of America
| | - Xin Wen
- Department of Pediatrics, New York University School of Medicine, New York, New York, United States of America
- NYU Cancer Institute, New York University School of Medicine, New York, New York, United States of America
- NYU Center for Health Informatics and Bioinformatics, New York University School of Medicine, New York, New York, United States of America
| | - Max T. Marcus
- Department of Neuroscience & Physiology, New York University School of Medicine, New York, New York, United States of America
| | - Garrett Daniels
- Department of Pathology, New York University School of Medicine, New York, New York, United States of America
| | - David Y. Zhang
- Department of Pathology, Mount Sinai School of Medicine, New York, New York, United States of America
| | - Fei Ye
- Department of Pathology, Mount Sinai School of Medicine, New York, New York, United States of America
| | - Ling Hang Wang
- Department of Pathology, New York University School of Medicine, New York, New York, United States of America
| | - Xinxin Du
- Department of Pathology, New York University School of Medicine, New York, New York, United States of America
| | - Sylvia Adams
- Department of Medicine, New York University School of Medicine, New York, New York, United States of America
- NYU Cancer Institute, New York University School of Medicine, New York, New York, United States of America
| | - Baljit Singh
- Department of Pathology, New York University School of Medicine, New York, New York, United States of America
- NYU Cancer Institute, New York University School of Medicine, New York, New York, United States of America
| | - Jiri Zavadil
- Department of Pathology, New York University School of Medicine, New York, New York, United States of America
- NYU Cancer Institute, New York University School of Medicine, New York, New York, United States of America
| | - Peng Lee
- Department of Pathology, New York University School of Medicine, New York, New York, United States of America
- NYU Cancer Institute, New York University School of Medicine, New York, New York, United States of America
- VA New York Harbor Healthcare System, New York, New York, United States of America
- *E-mail: (MM); (PL)
| | - Marie E. Monaco
- Department of Neuroscience & Physiology, New York University School of Medicine, New York, New York, United States of America
- NYU Cancer Institute, New York University School of Medicine, New York, New York, United States of America
- VA New York Harbor Healthcare System, New York, New York, United States of America
- *E-mail: (MM); (PL)
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108
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Milosevic J, Klinge J, Borg AL, Foukakis T, Bergh J, Tobin NP. Clinical instability of breast cancer markers is reflected in long-term in vitro estrogen deprivation studies. BMC Cancer 2013; 13:473. [PMID: 24119434 PMCID: PMC3852062 DOI: 10.1186/1471-2407-13-473] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Accepted: 10/08/2013] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND Long-term estrogen deprivation models are widely employed in an in vitro setting to recapitulate the hormonal milieu of breast cancer patients treated with endocrine therapy. Despite the wealth information we have garnered from these models thus far, a comprehensive time-course analysis of the estrogen (ER), progesterone (PR), and human epidermal growth factor 2 (HER-2/neu) receptors on the gene and protein level, coupled with expression array data is currently lacking. We aimed to address this knowledge gap in order to enhance our understanding of endocrine therapy resistance in breast cancer patients. METHODS ER positive MCF7 and BT474 breast cancer cells were grown in estrogen depleted medium for 10 months with the ER negative MDA-MB-231 cell line employed as control. ER, PR and HER-2/neu expression were analysed at defined short and long-term time points by immunocytochemistry (ICC), and quantitative real-time RT-PCR (qRT-PCR). Microarray analysis was performed on representative samples. RESULTS MCF7 cells cultured in estrogen depleted medium displayed decreasing expression of ER up to 8 weeks, which was then re-expressed at 10 months. PR was also down-regulated at early time points and remained so for the duration of the study. BT474 cells generally displayed no changes in ER during the first 8 weeks of deprivation, however its expression was significantly decreased at 10 months. PR expression was also down-regulated early in BT474 samples and was absent at later time points. Finally, microarray data revealed that genes and cell processes down-regulated in both cell lines at 6 weeks overlapped with those down-regulated in aromatase inhibitor treated breast cancer patients. CONCLUSIONS Our data demonstrate that expression of ER, PR, and cell metabolic/proliferative processes are unstable in response to long-term estrogen deprivation in breast cancer cell lines. These results mirror recent clinical findings and again emphasize the utility of LTED models in translational research.
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Affiliation(s)
- Jelena Milosevic
- Cancer Center Karolinska, Karolinska Institutet and University Hospital, Stockholm S-171 76, Sweden
| | - Johanna Klinge
- Cancer Center Karolinska, Karolinska Institutet and University Hospital, Stockholm S-171 76, Sweden
| | - Anna-Lena Borg
- Cancer Center Karolinska, Karolinska Institutet and University Hospital, Stockholm S-171 76, Sweden
| | - Theodoros Foukakis
- Cancer Center Karolinska, Karolinska Institutet and University Hospital, Stockholm S-171 76, Sweden
- Department of Oncology and Pathology, Radiumhemmet, Karolinska Institutet and University Hospital, Stockholm, Sweden
| | - Jonas Bergh
- Cancer Center Karolinska, Karolinska Institutet and University Hospital, Stockholm S-171 76, Sweden
- Department of Oncology and Pathology, Radiumhemmet, Karolinska Institutet and University Hospital, Stockholm, Sweden
- Honorary Professor, Manchester University, Manchester M20 4BX, England
| | - Nicholas P Tobin
- Cancer Center Karolinska, Karolinska Institutet and University Hospital, Stockholm S-171 76, Sweden
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109
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Extracellular alkaline pH leads to increased metastatic potential of estrogen receptor silenced endocrine resistant breast cancer cells. PLoS One 2013; 8:e76327. [PMID: 24098477 PMCID: PMC3788134 DOI: 10.1371/journal.pone.0076327] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Accepted: 08/23/2013] [Indexed: 01/18/2023] Open
Abstract
Introduction Endocrine resistance in breast cancer is associated with enhanced metastatic potential and poor clinical outcome, presenting a significant therapeutic challenge. We have established several endocrine insensitive breast cancer lines by shRNA induced depletion of estrogen receptor (ER) by transfection of MCF-7 cells which all exhibit enhanced expression profile of mesenchymal markers with reduction of epithelial markers, indicating an epithelial to mesenchymal transition. In this study we describe their behaviour in response to change in extracellular pH, an important factor controlling cell motility and metastasis. Methods Morphological changes associated with cell exposure to extracellular alkaline pH were assessed by live cell microscopy and the effect of various ion pumps on this behavior was investigated by pretreatment with chemical inhibitors. The activity and expression profile of key signaling molecules was assessed by western blotting. Cell motility and invasion were examined by scratch and under-agarose assays respectively. Total matrix metalloproteinase (MMP) activity and specifically of MMP2/9 was assessed in conditioned medium in response to brief alkaline pH exposure. Results Exposure of ER –ve but not ER +ve breast cancer cells to extracellular alkaline pH resulted in cell shrinkage and spherical appearance (termed contractolation); this was reversed by returning the pH back to 7.4. Contractolation was blocked by targeting the Na+/K+ and Na+/H+ pumps with specific chemical inhibitors. The activity and expression profile of key signaling molecules critical for cell adhesion were modulated by the exposure to alkaline pH. Brief exposure to alkaline pH enhanced MMP2/9 activity and the invasive potential of ER –ve cells in response to serum components and epithelial growth factor stimulation without affecting unhindered motility. Conclusions Endocrine resistant breast cancer cells behave very differently to estrogen responsive cells in alkaline pH, with enhanced invasive potential; these studies emphasise the crucial influence of extracellular pH and caution against indiscriminate application of alkalinising drug therapy.
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110
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Yang KM, Jung Y, Lee JM, Kim W, Cho JK, Jeong J, Kim SJ. Loss of TBK1 Induces Epithelial–Mesenchymal Transition in the Breast Cancer Cells by ERα Downregulation. Cancer Res 2013; 73:6679-89. [DOI: 10.1158/0008-5472.can-13-0891] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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111
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El-Hashim AZ, Jaffal SM, Al-Rashidi FT, Luqmani YA, Akhtar S. Nerve growth factor enhances cough via a central mechanism of action. Pharmacol Res 2013; 74:68-77. [DOI: 10.1016/j.phrs.2013.05.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Revised: 05/22/2013] [Accepted: 05/23/2013] [Indexed: 12/21/2022]
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112
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Karihtala P, Auvinen P, Kauppila S, Haapasaari KM, Jukkola-Vuorinen A, Soini Y. Vimentin, zeb1 and Sip1 are up-regulated in triple-negative and basal-like breast cancers: association with an aggressive tumour phenotype. Breast Cancer Res Treat 2013; 138:81-90. [DOI: 10.1007/s10549-013-2442-0] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Accepted: 01/31/2013] [Indexed: 01/27/2023]
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113
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Al-Saeedi FJ, Mathew PM, Luqmani YA. Assessment of tracer 99mTc(V)-DMSA uptake as a measure of tumor cell proliferation in vitro. PLoS One 2013; 8:e54361. [PMID: 23335999 PMCID: PMC3545874 DOI: 10.1371/journal.pone.0054361] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2012] [Accepted: 12/11/2012] [Indexed: 01/27/2023] Open
Abstract
PURPOSE To examine whether (99m)Tc(V)-DMSA could be used as a non-invasive measure of cancer cell proliferation. METHODS Human breast cancer MCF-7, MDA-MB-231 and pII, and prostate cancer PC-3 cell lines were grown to 30, 50 and 100% confluency and pulsed with (99m)Tc(V)-DMSA in media for 60 min at 37°C. DNA synthesis was analysed by quantification of the S phase using flow cytometry, [methyl-(3)H]thymidine incorporation and expression of proliferation markers PCNA and Ki-67 using realtime PCR. One way ANOVA was used to compare groups. RESULTS In all cell lines rates of (99m)Tc(V)-DMSA uptake were inversely related to cell density. This was paralleled by similar trends in S phase proportions, [methyl-(3)H]thymidine incorporation and expression of PCNA and Ki-67. CONCLUSION Rates of (99m)Tc(V)-DMSA uptake into different types of tumour cells correlate well with cell density that is useful as a non-invasive measure of tumour cellular proliferation in vivo.
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Affiliation(s)
- Fatma J Al-Saeedi
- Nuclear Medicine Department, Faculty of Medicine, Health Sciences Center, Kuwait University, Hawally, Jabriya, Kuwait.
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114
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Abstract
Breast cancer is the most common malignancy in women and a significant cause of morbidity and mortality. Sub-types of breast cancer defined by the expression of steroid hormones and Her2/Neu oncogene have distinct prognosis and undergo different therapies. Besides differing in their phenotype, sub-types of breast cancer display various molecular lesions that participate in their pathogenesis. BRCA1 is one of the common hereditary cancer predisposition genes and encodes for an ubiquitin ligase. Ubiquitin ligases or E3 enzymes participate together with ubiquitin activating enzyme and ubiquitin conjugating enzymes in the attachment of ubiquitin (ubiquitination) in target proteins. Ubiquitination is a post-translational modification regulating multiple cell functions. It also plays important roles in carcinogenesis in general and in breast carcinogenesis in particular. Ubiquitin conjugating enzymes are a central component of the ubiquitination machinery and are often perturbed in breast cancer. This paper will discuss ubiquitin and ubiquitin-like proteins conjugating enzymes participating in breast cancer pathogenesis, their relationships with other proteins of the ubiquitination machinery and their role in phenotype of breast cancer sub-types.
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Affiliation(s)
- Ioannis A Voutsadakis
- Centre Pluridisciplinaire d'Oncologie, BH06, University Hospital of Lausanne, Lausanne, Switzerland.
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115
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Khajah MA, Al Saleh S, Mathew PM, Luqmani YA. Differential effect of growth factors on invasion and proliferation of endocrine resistant breast cancer cells. PLoS One 2012; 7:e41847. [PMID: 22860018 PMCID: PMC3408495 DOI: 10.1371/journal.pone.0041847] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Accepted: 06/29/2012] [Indexed: 01/27/2023] Open
Abstract
We have established several breast cancer cell lines that exhibit a permanent ER-depleted phenotype, induced by shRNA transfection of MCF-7 cells, which afford a useful model for studying acquired endocrine resistance. Previously we showed that MDA-231 as well as ER-silenced cells could invade through simulated extracellular matrix components. However, the contribution of individual serum components responsible for cell invasion was not determined. In the present study, an under-agarose gel assay was used to quantitatively assess the invasive movement of two ER-silenced cell lines (pII and YS2.5) in comparison to the parental MCF-7, the ER negative MDA-231, and normal HBL100 cells, as well as a line that was ER-shRNA transfected but failed to exhibit ER down-regulation (YS1.2). We also examined the effect of the growth factors EGF, IGF-1, TGFβ, PDGFC and RANTES on pII cell invasion and proliferation. All breast cancer cell lines which had reduced ER expression exhibited a serum-dependent invasive ability related to the degree of induced ER loss. TGFβ treatment inhibited pII cell proliferation and enhanced their invasive ability but at a relatively high dose. IGF-1 and EGF enhanced pII cell proliferation, with the latter playing the major role in promoting cell invasion. PDGFC did not affect either process although it is highly expressed in pII cells. Differential effects were observed on activation of Akt and ERK1/2 suggesting their involvement as intracellular mediators of EGF induced invasion, in part through the regulation of matrix metalloproteinase activity. Targeting EGF receptor tyrosine kinase activity by erlotinib resulted in significant inhibition of both pII cell proliferation and directional invasion towards EGF suggesting that this drug has potential therapeutic usefulness for preventing spread of particularly endocrine resistant breast cancer.
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116
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Giannoni E, Parri M, Chiarugi P. EMT and oxidative stress: a bidirectional interplay affecting tumor malignancy. Antioxid Redox Signal 2012; 16:1248-63. [PMID: 21929373 DOI: 10.1089/ars.2011.4280] [Citation(s) in RCA: 168] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
SIGNIFICANCE Epithelial-mesenchymal transition (EMT) is emerging as a driving force in tumor progression, enabling cancer cells to evade their "homeland" and to colonize remote locations. In this review, we focus on the emerging views dealing with a redox control of EMT and with the importance of a pro-oxidant environment, both in cancer and stromal cells, to attain an improvement in tumor malignancy. RECENT ADVANCES The variety of signals able to promote EMT is large and continuously growing, ranging from soluble factors to components of the extracellular matrix. Compelling evidence highlights reactive oxygen species (ROS) as crucial conspirators in EMT engagement. CRITICAL ISSUES Tumor microenvironment exploits a fascinating role in ensuring EMT outcome within the primary tumor, granting for the achievement of an essential selective advantage for cancer cells. Cancer-associated fibroblasts, macrophages, and hypoxia are major players in this scenario, exerting a propelling role for EMT, as well as for invasiveness, stemness, and dissemination of metastatic cells. FUTURE DIRECTIONS Future research focused on EMT should address some key points that are still unclear. They include: i) the role of the reverse phenomenon (i.e., mesenchymal-epithelial transition) that is likely regulated in the final stages of tumor progression, or that of mesenchymal-amoeboid transition, a plasticity program of cancer cells, which often follows EMT and offers a further metastatic advantage, and ii) the molecular basis of the correlation between stemness, EMT and ROS content.
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Affiliation(s)
- Elisa Giannoni
- Department of Biochemical Sciences, University of Florence, Tuscany Tumor Institute, and Center for Research, Transfer and High Education DenoTHE, Florence, Italy.
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Saha S, Duan X, Wu L, Lo PK, Chen H, Wang Q. Electrospun fibrous scaffolds promote breast cancer cell alignment and epithelial-mesenchymal transition. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:2028-34. [PMID: 22182057 PMCID: PMC3269532 DOI: 10.1021/la203846w] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
In this work we created electrospun fibrous scaffolds with random and aligned fiber orientations in order to mimic the three-dimensional structure of the natural extracellular matrix (ECM). The rigidity and topography of the ECM environment have been reported to alter cancer cell behavior. However, the complexity of the in vivo system makes it difficult to isolate and study such extracellular topographical cues that trigger cancer cells' response. Breast cancer cells were cultured on these fibrous scaffolds for 3-5 days. The cells showed elongated spindle-like morphology in the aligned fibers, whereas they maintained a mostly flat stellar shape in the random fibers. Gene expression profiling of these cells post seeding showed up-regulation of transforming growth factor β-1 (TGFβ-1) along with other mesenchymal biomarkers, suggesting that these cells undergo epithelial-mesenchymal transitions in response to the polymer scaffold. The results of this study indicate that the topographical cue may play a significant role in tumor progression.
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Affiliation(s)
- Sharmistha Saha
- Department of Chemistry and Biochemistry & Nanocenter, University of South Carolina, Columbia, SC, 29208, USA
| | - Xinrui Duan
- Department of Chemistry and Biochemistry & Nanocenter, University of South Carolina, Columbia, SC, 29208, USA
| | - Laying Wu
- Department of Chemistry and Biochemistry & Nanocenter, University of South Carolina, Columbia, SC, 29208, USA
| | - Pang-Kuo Lo
- Department of Biological Sciences, University of South Carolina, Columbia, SC, 29208, USA
| | - Hexin Chen
- Department of Biological Sciences, University of South Carolina, Columbia, SC, 29208, USA
| | - Qian Wang
- Department of Chemistry and Biochemistry & Nanocenter, University of South Carolina, Columbia, SC, 29208, USA
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