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Kawagishi-Hotta M, Hasegawa S, Hasebe Y, Inoue Y, Okuno R, Arima M, Iwata Y, Sugiura K, Akamatsu H. Increase in Inhibin beta A/Activin-A expression in the human epidermis and the suppression of epidermal stem/progenitor cell proliferation with aging. J Dermatol Sci 2022; 106:150-158. [DOI: 10.1016/j.jdermsci.2022.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 03/21/2022] [Accepted: 05/05/2022] [Indexed: 11/25/2022]
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Kim HJ, Bae IH, Son ED, Park J, Cha N, Na HW, Jung C, Go YS, Kim DY, Lee TR, Shin DW. Transcriptome analysis of airborne PM 2.5-induced detrimental effects on human keratinocytes. Toxicol Lett 2017; 273:26-35. [PMID: 28341207 DOI: 10.1016/j.toxlet.2017.03.010] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 03/09/2017] [Accepted: 03/10/2017] [Indexed: 11/24/2022]
Abstract
Ambient air pollution is becoming more severe worldwide, posing a serious threat to human health. Fine airborne particles of particulate matter (PM2.5) show higher cytotoxicity than other coarse fractions. Indeed, PM2.5 induces cardiovascular or respiratory damage; however, few studies have evaluated the detrimental effect of PM2.5 to normal human skin. We used a next-generation sequencing-based (RNA-Seq) method with transcriptome and Gene Ontology (GO) enrichment analysis to determine the harmful influences of PM2.5 on human normal epidermal keratinocytes. DAVID analysis showed that the most significantly enriched GO terms were associated with epidermis-related biological processes such as "epidermis development (GO: 0008544)" and "keratinocyte differentiation (GO: 0030216)", suggesting that PM2.5 has some deleterious effects to the human epidermis. In addition, Ingenuity Pathway Analysis predicted inflammation-related signaling as one of the major PM2.5-induced signaling pathways, and pro-inflammatory cytokines as upstream regulators with symptoms similar to psoriasis as downstream effects. PM2.5 caused considerable changes in the expression of pro-inflammatory cytokines and psoriatic skin disease-related genes, might lead to epidermal dysfunctions. Our results might help to understand the mechanism of air pollution-induced skin barrier perturbation and contribute to the development of a new strategy for the prevention or recovery of the consequent damage.
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Affiliation(s)
- Hyoung-June Kim
- Amorepacific Corporation R&D Center, Yongin-si, Gyeonggi-do, 446-729, Republic of Korea
| | - Il-Hong Bae
- Amorepacific Corporation R&D Center, Yongin-si, Gyeonggi-do, 446-729, Republic of Korea; College of Veterinary Medicine, Seoul National University, Seoul, 151-742 Republic of Korea
| | - Eui Dong Son
- Amorepacific Corporation R&D Center, Yongin-si, Gyeonggi-do, 446-729, Republic of Korea
| | - Juyearl Park
- Amorepacific Corporation R&D Center, Yongin-si, Gyeonggi-do, 446-729, Republic of Korea
| | - Nari Cha
- Amorepacific Corporation R&D Center, Yongin-si, Gyeonggi-do, 446-729, Republic of Korea
| | - Hye-Won Na
- Amorepacific Corporation R&D Center, Yongin-si, Gyeonggi-do, 446-729, Republic of Korea
| | - Changjo Jung
- Amorepacific Corporation R&D Center, Yongin-si, Gyeonggi-do, 446-729, Republic of Korea
| | - You-Seak Go
- Macrogen Inc., Seoul, 08511, Republic of Korea
| | - Dae-Yong Kim
- College of Veterinary Medicine, Seoul National University, Seoul, 151-742 Republic of Korea
| | - Tae Ryong Lee
- Amorepacific Corporation R&D Center, Yongin-si, Gyeonggi-do, 446-729, Republic of Korea.
| | - Dong Wook Shin
- Amorepacific Corporation R&D Center, Yongin-si, Gyeonggi-do, 446-729, Republic of Korea.
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Méndez-López LF, Davila-Velderrain J, Domínguez-Hüttinger E, Enríquez-Olguín C, Martínez-García JC, Alvarez-Buylla ER. Gene regulatory network underlying the immortalization of epithelial cells. BMC SYSTEMS BIOLOGY 2017; 11:24. [PMID: 28209158 PMCID: PMC5314717 DOI: 10.1186/s12918-017-0393-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 01/11/2017] [Indexed: 12/25/2022]
Abstract
BACKGROUND Tumorigenic transformation of human epithelial cells in vitro has been described experimentally as the potential result of spontaneous immortalization. This process is characterized by a series of cell-state transitions, in which normal epithelial cells acquire first a senescent state which is later surpassed to attain a mesenchymal stem-like phenotype with a potentially tumorigenic behavior. In this paper we aim to provide a system-level mechanistic explanation to the emergence of these cell types, and to the time-ordered transition patterns that are common to neoplasias of epithelial origin. To this end, we first integrate published functional and well-curated molecular data of the components and interactions that have been found to be involved in such cell states and transitions into a network of 41 molecular components. We then reduce this initial network by removing simple mediators (i.e., linear pathways), and formalize the resulting regulatory core into logical rules that govern the dynamics of each of the network components as a function of the states of its regulators. RESULTS Computational dynamic analysis shows that our proposed Gene Regulatory Network model recovers exactly three attractors, each of them defined by a specific gene expression profile that corresponds to the epithelial, senescent, and mesenchymal stem-like cellular phenotypes, respectively. We show that although a mesenchymal stem-like state can be attained even under unperturbed physiological conditions, the likelihood of converging to this state is increased when pro-inflammatory conditions are simulated, providing a systems-level mechanistic explanation for the carcinogenic role of chronic inflammatory conditions observed in the clinic. We also found that the regulatory core yields an epigenetic landscape that restricts temporal patterns of progression between the steady states, such that recovered patterns resemble the time-ordered transitions observed during the spontaneous immortalization of epithelial cells, both in vivo and in vitro. CONCLUSION Our study strongly suggests that the in vitro tumorigenic transformation of epithelial cells, which strongly correlates with the patterns observed during the pathological progression of epithelial carcinogenesis in vivo, emerges from underlying regulatory networks involved in epithelial trans-differentiation during development.
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Affiliation(s)
- Luis Fernando Méndez-López
- Centro de Investigación y Desarrollo en Ciencias de la Salud (CIDICS), Universidad Autonoma de Nuevo Leon, A. P. 14-740, México, 07300 D.F México
| | | | - Elisa Domínguez-Hüttinger
- Instituto de Ecología, UNAM, Cd. Universitaria, México, 04510 D.F México
- Centro de Ciencias de la Complejidad, UNAM, Cd. Universitaria, México, 04510 D.F México
| | | | | | - Elena R. Alvarez-Buylla
- Instituto de Ecología, UNAM, Cd. Universitaria, México, 04510 D.F México
- Centro de Ciencias de la Complejidad, UNAM, Cd. Universitaria, México, 04510 D.F México
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Park H, Kim CH, Jeong JH, Park M, Kim KS. GDF15 contributes to radiation-induced senescence through the ROS-mediated p16 pathway in human endothelial cells. Oncotarget 2016; 7:9634-44. [PMID: 26909594 PMCID: PMC4891072 DOI: 10.18632/oncotarget.7457] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Accepted: 02/08/2016] [Indexed: 11/25/2022] Open
Abstract
Growth differentiation factor 15 (GDF15) is an emerging biomarker of cardiovascular risk and disease. Microarray analyses revealed that GDF15 levels were increased during cellular senescence induced by ionizing radiation (IR) in human aortic endothelial cells (HAECs). However, the role of GDF15 in HAEC cellular senescence remains unclear. This study demonstrated that downregulation of GDF15 in HAECs partially prevented cellular senescence triggered by IR, which was confirmed by recovery of cell proliferation and reverse senescence-associated β-galactosidase (SA-β-gal) staining. Conversely, upregulation of GDF15-induced cellular senescence in HAECs, confirmed by G0/G1 cell cycle arrest, decreased during cell proliferation and increased SA-β-gal staining. GDF15-induced cellular senescence was observed in p16-knockdown cells but not in p53-knockdown cells. GDF15 expression in endothelial cells also generated reactive oxygen species (ROS), which led to activation of extracellular signal-regulated kinases (ERKs) and induction of senescence by oxidative stress. These results suggested that GDF15 might play an important role in cellular senescence through a ROS-mediated p16 pathway and contribute to the pathogenesis of atherosclerosis via pro-senescent activity.
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Affiliation(s)
- Hyejin Park
- Divisions of Radiation Effects, Korea Institute of Radiological and Medical Sciences, Seoul, Republic of Korea
| | - Chun-Ho Kim
- Divisions of Radiation Effects, Korea Institute of Radiological and Medical Sciences, Seoul, Republic of Korea
| | - Jae-Hoon Jeong
- Research Center for Radiotherapy, Korea Institute of Radiological and Medical Sciences, Seoul, Republic of Korea
| | - Myungjin Park
- Divisions of Radiation Cancer Science, Korea Institute of Radiological and Medical Sciences, Seoul, Republic of Korea
| | - Kwang Seok Kim
- Divisions of Radiation Effects, Korea Institute of Radiological and Medical Sciences, Seoul, Republic of Korea
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Abstract
SIGNIFICANCE For a healthy cell to turn into a cancer cell and grow out to become a tumor, it needs to undergo a series of complex changes and acquire certain traits, summarized as "The Hallmarks of Cancer." These hallmarks can all be regarded as the result of altered signal transduction cascades and an understanding of these cascades is essential for cancer treatment. RECENT ADVANCES Redox signaling is a long overlooked form of signal transduction that proceeds through the reversible oxidation of cysteines in proteins and that uses hydrogen peroxide as a second messenger. CRITICAL ISSUES In this article, we provide examples that show that redox signaling is involved in the regulation of proteins and signaling cascades that play roles in every hallmark of cancer. FUTURE DIRECTIONS An understanding of how redox signaling and "classical" signal transduction are intertwined could hold promising strategies for cancer therapy in the future. Antioxid. Redox Signal. 25, 300-325.
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Affiliation(s)
- Marten Hornsveld
- Department of Molecular Cancer Research, Center for Molecular Medicine, University Medical Center Utrecht , Utrecht, the Netherlands
| | - Tobias B Dansen
- Department of Molecular Cancer Research, Center for Molecular Medicine, University Medical Center Utrecht , Utrecht, the Netherlands
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Lee CM, Gupta S, Wang J, Johnson EM, Crofford LJ, Marshall JC, Kapoor M, Hu J. Epithelium-specific Ets transcription factor-1 acts as a negative regulator of cyclooxygenase-2 in human rheumatoid arthritis synovial fibroblasts. Cell Biosci 2016; 6:43. [PMID: 27313839 PMCID: PMC4910355 DOI: 10.1186/s13578-016-0105-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 05/25/2016] [Indexed: 01/21/2023] Open
Abstract
Background Rheumatoid arthritis (RA) is characterized by excessive synovial inflammation. Cyclooxygenase-2 (COX-2) is an enzyme that catalyzes the conversion of arachidonic acid (AA) into prostaglandins. Epithelium-specific Ets transcription factor-1 (ESE-1) was previously demonstrated to upregulate COX-2 in co-operation with nuclear factor kappa B (NFκB) in macrophages and chondrocytes. However, the role of ESE-1 in RA pathology has remained unclear. In this study, we aimed to elucidate the relationship between ESE-1 and COX-2 in RA synovial fibroblasts (RASFs) using a HD-Ad-mediated knockdown approach. Results ESE-1 and COX-2 were induced by IL-1β in RASFs that corresponded with an increase in PGE2. Endogenous levels of ESE-1 and COX-2 in human RASFs were analyzed by RT-qPCR and Western blot, and PGE2 was quantified using competitive ELISA. Interestingly, knockdown of ESE-1 using helper-dependent adenovirus (HD-Ad) led to a significant upregulation of COX-2 at a later phase of IL-1β stimulation. Examination of ESE-1 intracellular localization by nuclear fractionation revealed that ESE-1 was localized in the nucleus, occupying disparate cellular compartments to NFκB when COX-2 was increased. To confirm the ESE-1-COX-2 relationship in other cellular systems, COX-2 was also measured in SW982 synovial sarcoma cell line and ESE-1 knockout (KO) murine macrophages. Similarly, knockdown of ESE-1 transcriptionally upregulated COX-2 in SW982 and ESE-1 KO murine macrophages, suggesting that ESE-1 may be involved in the resolution of inflammation. Conclusion ESE-1 acts as a negative regulator of COX-2 in human RASFs and its effect on COX-2 is NFκB-independent. Electronic supplementary material The online version of this article (doi:10.1186/s13578-016-0105-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Chan-Mi Lee
- SickKids Research Institute, Program in Physiology and Experimental Medicine, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, 9th floor, 686 Bay Street, Toronto, ON M5G 0A4 Canada ; Laboratory Medicine and Pathobiology, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8 Canada
| | - Sahil Gupta
- The Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, 209 Victoria Street, Toronto, ON M5B 1T8 Canada ; Institute of Medical Science, Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8 Canada
| | - Jiafeng Wang
- The Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, 209 Victoria Street, Toronto, ON M5B 1T8 Canada ; Department of Anesthesiology and Intensive Care, The Second Military Medical University, Changhai Hospital, Shanghai, 200433 China
| | - Elizabeth M Johnson
- Department of Medicine, Division of Rheumatology and Immunology, School of Medicine, Vanderbilt University, 1161 21st Ave S, MCN T-3113, Nashville, TN 37232 USA
| | - Leslie J Crofford
- Department of Medicine, Division of Rheumatology and Immunology, School of Medicine, Vanderbilt University, 1161 21st Ave S, MCN T-3113, Nashville, TN 37232 USA
| | - John C Marshall
- The Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, 209 Victoria Street, Toronto, ON M5B 1T8 Canada ; Institute of Medical Science, Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8 Canada ; Department of Surgery, St. Michael's Hospital, University of Toronto, 30 Bond Street, Toronto, ON M5B 1W8 Canada
| | - Mohit Kapoor
- Laboratory Medicine and Pathobiology, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8 Canada ; Division of Genetics and Development, Toronto Western Research Institute, Toronto Western Hospital, University Health Network (UHN), 60 Leonard Avenue, Toronto, ON M5T 2S8 Canada
| | - Jim Hu
- SickKids Research Institute, Program in Physiology and Experimental Medicine, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, 9th floor, 686 Bay Street, Toronto, ON M5G 0A4 Canada ; Laboratory Medicine and Pathobiology, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8 Canada ; Institute of Medical Science, Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8 Canada
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Ryan MM, Morris GP, Mockett BG, Bourne K, Abraham WC, Tate WP, Williams JM. Time-dependent changes in gene expression induced by secreted amyloid precursor protein-alpha in the rat hippocampus. BMC Genomics 2013; 14:376. [PMID: 23742273 PMCID: PMC3691674 DOI: 10.1186/1471-2164-14-376] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Accepted: 05/24/2013] [Indexed: 01/19/2023] Open
Abstract
Background Differential processing of the amyloid precursor protein liberates either amyloid-ß, a causative agent of Alzheimer’s disease, or secreted amyloid precursor protein-alpha (sAPPα), which promotes neuroprotection, neurotrophism, neurogenesis and synaptic plasticity. The underlying molecular mechanisms recruited by sAPPα that underpin these considerable cellular effects are not well elucidated. As these effects are enduring, we hypothesised that regulation of gene expression may be of importance and examined temporally specific gene networks and pathways induced by sAPPα in rat hippocampal organotypic slice cultures. Slices were exposed to 1 nM sAPPα or phosphate buffered saline for 15 min, 2 h or 24 h and sAPPα-associated gene expression profiles were produced for each time-point using Affymetrix Rat Gene 1.0 ST arrays (moderated t-test using Limma: p < 0.05, and fold change ± 1.15). Results Treatment of organotypic hippocampal slice cultures with 1 nM sAPPα induced temporally distinct gene expression profiles, including mRNA and microRNA associated with Alzheimer’s disease. Having demonstrated that treatment with human recombinant sAPPα was protective against N-methyl d-aspartate-induced toxicity, we next explored the sAPPα-induced gene expression profiles. Ingenuity Pathway Analysis predicted that short-term exposure to sAPPα elicited a multi-level transcriptional response, including upregulation of immediate early gene transcription factors (AP-1, Egr1), modulation of the chromatin environment, and apparent activation of the constitutive transcription factors CREB and NF-κB. Importantly, dynamic regulation of NF-κB appears to be integral to the transcriptional response across all time-points. In contrast, medium and long exposure to sAPPα resulted in an overall downregulation of gene expression. While these results suggest commonality between sAPPα and our previously reported analysis of plasticity-related gene expression, we found little crossover between these datasets. The gene networks formed following medium and long exposure to sAPPα were associated with inflammatory response, apoptosis, neurogenesis and cell survival; functions likely to be the basis of the neuroprotective effects of sAPPα. Conclusions Our results demonstrate that sAPPα rapidly and persistently regulates gene expression in rat hippocampus. This regulation is multi-level, temporally specific and is likely to underpin the neuroprotective effects of sAPPα.
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Affiliation(s)
- Margaret M Ryan
- Brain Health Research Centre, University of Otago, PO Box 56, Dunedin New Zealand.
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Diaz-Moralli S, Tarrado-Castellarnau M, Miranda A, Cascante M. Targeting cell cycle regulation in cancer therapy. Pharmacol Ther 2013; 138:255-71. [PMID: 23356980 DOI: 10.1016/j.pharmthera.2013.01.011] [Citation(s) in RCA: 237] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2012] [Accepted: 12/26/2012] [Indexed: 01/10/2023]
Abstract
Cell proliferation is an essential mechanism for growth, development and regeneration of eukaryotic organisms; however, it is also the cause of one of the most devastating diseases of our era: cancer. Given the relevance of the processes in which cell proliferation is involved, its regulation is of paramount importance for multicellular organisms. Cell division is orchestrated by a complex network of interactions between proteins, metabolism and microenvironment including several signaling pathways and mechanisms of control aiming to enable cell proliferation only in response to specific stimuli and under adequate conditions. Three main players have been identified in the coordinated variation of the many molecules that play a role in cell cycle: i) The cell cycle protein machinery including cyclin-dependent kinases (CDK)-cyclin complexes and related kinases, ii) The metabolic enzymes and related metabolites and iii) The reactive-oxygen species (ROS) and cellular redox status. The role of these key players and the interaction between oscillatory and non-oscillatory species have proved essential for driving the cell cycle. Moreover, cancer development has been associated to defects in all of them. Here, we provide an overview on the role of CDK-cyclin complexes, metabolic adaptations and oxidative stress in regulating progression through each cell cycle phase and transitions between them. Thus, new approaches for the design of innovative cancer therapies targeting crosstalk between cell cycle simultaneous events are proposed.
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Affiliation(s)
- Santiago Diaz-Moralli
- Faculty of Biology, Department of Biochemistry and Molecular Biology, Universitat de Barcelona, Barcelona, Spain
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Rayess H, Wang MB, Srivatsan ES. Cellular senescence and tumor suppressor gene p16. Int J Cancer 2011; 130:1715-25. [PMID: 22025288 DOI: 10.1002/ijc.27316] [Citation(s) in RCA: 499] [Impact Index Per Article: 38.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Accepted: 10/14/2011] [Indexed: 12/14/2022]
Abstract
Cellular senescence is an irreversible arrest of cell growth. Biochemical and morphological changes occur during cellular senescence, including the formation of a unique cellular morphology such as flattened cytoplasm. Function of mitochondria, endoplasmic reticulum and lysosomes are affected resulting in the inhibition of lysosomal and proteosomal pathways. Cellular senescence can be triggered by a number of factors including, aging, DNA damage, oncogene activation and oxidative stress. While the molecular mechanism of senescence involves p16 and p53 tumor suppressor genes and telomere shortening, this review is focused on the mechanism of p16 control. The p16-mediated senescence acts through the retinoblastoma (Rb) pathway inhibiting the action of the cyclin dependant kinases leading to G1 cell cycle arrest. Rb is maintained in a hypophosphorylated state resulting in the inhibition of transcription factor E2F1. Regulation of p16 expression is complex and involves epigenetic control and multiple transcription factors. PRC1 (Pombe repressor complex (1) and PRC2 (Pombe repressor complex (2) proteins and histone deacetylases play an important role in the promoter hypermethylation for suppressing p16 expression. While transcription factors YY1 and Id1 suppress p16 expression, transcription factors CTCF, Sp1 and Ets family members activate p16 transcription. Senescence occurs with the inactivation of suppressor elements leading to the enhanced expression of p16.
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Affiliation(s)
- Hani Rayess
- Department of Surgery, VA Greater Los Angeles Healthcare system, West Los Angeles, CA, USA
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Identification of target genes for wild type and truncated HMGA2 in mesenchymal stem-like cells. BMC Cancer 2010; 10:329. [PMID: 20576167 PMCID: PMC2912264 DOI: 10.1186/1471-2407-10-329] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2010] [Accepted: 06/25/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The HMGA2 gene, coding for an architectural transcription factor involved in mesenchymal embryogenesis, is frequently deranged by translocation and/or amplification in mesenchymal tumours, generally leading to over-expression of shortened transcripts and a truncated protein. METHODS To identify pathways that are affected by sarcoma-associated variants of HMGA2, we have over-expressed wild type and truncated HMGA2 protein in an immortalized mesenchymal stem-like cell (MSC) line, and investigated the localisation of these proteins and their effects on differentiation and gene expression patterns. RESULTS Over-expression of both transgenes blocked adipogenic differentiation of these cells, and microarray analysis revealed clear changes in gene expression patterns, more pronounced for the truncated protein. Most of the genes that showed altered expression in the HMGA2-overexpressing cells fell into the group of NF-kappaB-target genes, suggesting a central role for HMGA2 in this pathway. Of particular interest was the pronounced up-regulation of SSX1, already implicated in mesenchymal oncogenesis and stem cell functions, only in cells expressing the truncated protein. Furthermore, over-expression of both HMGA2 forms was associated with a strong repression of the epithelial marker CD24, consistent with the reported low level of CD24 in cancer stem cells. CONCLUSIONS We conclude that the c-terminal part of HMGA2 has important functions at least in mesenchymal cells, and the changes in gene expression resulting from overexpressing a protein lacking this domain may add to the malignant potential of sarcomas.
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Swindell WR. Genes and gene expression modules associated with caloric restriction and aging in the laboratory mouse. BMC Genomics 2009; 10:585. [PMID: 19968875 PMCID: PMC2795771 DOI: 10.1186/1471-2164-10-585] [Citation(s) in RCA: 127] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2009] [Accepted: 12/07/2009] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND Caloric restriction (CR) counters deleterious effects of aging and, for most mouse genotypes, increases mean and maximum lifespan. Previous analyses of microarray data have identified gene expression responses to CR that are shared among multiple mouse tissues, including the activation of anti-oxidant, tumor suppressor and anti-inflammatory pathways. These analyses have provided useful research directions, but have been restricted to a limited number of tissues, and have focused on individual genes, rather than whole-genome transcriptional networks. Furthermore, CR is thought to oppose age-associated gene expression patterns, but detailed statistical investigations of this hypothesis have not been carried out. RESULTS Systemic effects of CR and aging were identified by examining transcriptional responses to CR in 17 mouse tissue types, as well as responses to aging in 22 tissues. CR broadly induced the expression of genes known to inhibit oxidative stress (e.g., Mt1, Mt2), inflammation (e.g., Nfkbia, Timp3) and tumorigenesis (e.g., Txnip, Zbtb16). Additionally, a network-based investigation revealed that CR regulates a large co-expression module containing genes associated with the metabolism and splicing of mRNA (e.g., Cpsf6, Sfpq, Sfrs18). The effects of aging were, to a considerable degree, similar among groups of co-expressed genes. Age-related gene expression patterns characteristic of most mouse tissues were identified, including up regulation of granulin (Grn) and secreted phosphoprotein 1 (Spp1). The transcriptional association between CR and aging varied at different levels of analysis. With respect to gene subsets associated with certain biological processes (e.g., immunity and inflammation), CR opposed age-associated expression patterns. However, among all genes, global transcriptional effects of CR were only weakly related to those of aging. CONCLUSION The study of aging, and of interventions thought to combat aging, has much to gain from data-driven and unbiased genomic investigations. Expression patterns identified in this analysis characterize a generalized response of mammalian cells to CR and/or aging. These patterns may be of importance in determining effects of CR on overall lifespan, or as factors that underlie age-related disease. The association between CR and aging warrants further study, but most evidence indicates that CR does not induce a genome-wide "reversal" of age-associated gene expression patterns.
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Affiliation(s)
- William R Swindell
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109-2200, USA.
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Burhans WC, Heintz NH. The cell cycle is a redox cycle: linking phase-specific targets to cell fate. Free Radic Biol Med 2009; 47:1282-93. [PMID: 19486941 DOI: 10.1016/j.freeradbiomed.2009.05.026] [Citation(s) in RCA: 254] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2009] [Revised: 05/19/2009] [Accepted: 05/22/2009] [Indexed: 11/22/2022]
Abstract
Reactive oxygen species (ROS) regulate the strength and duration of signaling through redox-dependent signal transduction pathways via the cyclic oxidation/reduction of cysteine residues in kinases, phosphatases, and other regulatory factors. Signaling circuits may be segregated in organelles or other subcellular domains with distinct redox states, permitting them to respond independently to changes in the oxidation state of two major thiol reductants, glutathione and thioredoxin. Studies in yeast, and in complex eukaryotes, show that oscillations in oxygen consumption, energy metabolism, and redox state are intimately integrated with cell cycle progression. Because signaling pathways play specific roles in different phases of the cell cycle and the hierarchy of redox-dependent regulatory checkpoints changes during cell cycle progression, the effects of ROS on cell fate vary during the cell cycle. In G1, ROS stimulate mitogenic pathways that control the activity of cyclin-dependent kinases (CDKs) and phosphorylation of the retinoblastoma protein (pRB), thereby regulating S-phase entry. In response to oxidative stress, Nrf2 and Foxo3a promote cell survival by inducing the expression of antioxidant enzymes and factors involved in cell cycle withdrawal, such as the cyclin-dependent kinase inhibitor (CKI) p27. In S phase, ROS induce S-phase arrest via PP2A-dependent dephosphorylation of pRB. In precancerous cells, unconstrained mitogenic signaling by activated oncogenes induces replication stress in S phase, which activates the DNA-damage response and induces cell senescence. A number of studies suggest that interactions of ROS with the G1 CDK/CKI network play a fundamental role in senescence, which is considered a barrier to tumorigenesis. Adaptive responses and loss of checkpoint proteins such as p53 and p16(INK4a) allow tumor cells to tolerate constitutive mitogenic signaling and enhanced production of ROS, leading to altered redox status in many fully transformed cells. Alterations in oxidant and energy metabolism of cancer cells have emerged as fertile ground for new therapeutic targets. The present challenge is to identify redox-dependent targets relevant to each cell cycle phase, to understand how these targets control fate decisions, and to describe the mechanisms that link metabolism to cell cycle progression.
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Affiliation(s)
- William C Burhans
- Department of Molecular & Cellular Biology, Roswell Park Cancer Institute, Buffalo, NY 14263, USA
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Abstract
In normal tissue, cell division is carefully regulated to maintain the correct proliferative balance. Abnormal cell division underlies many hypoproliferative and hyperproliferative disorders, including cancer, and a better understanding of the mechanisms involved could lead to new strategies for treatment and prevention. Cellular senescence, a state of irreversible growth arrest, was first described as a limit to the replicative life span of somatic cells after serial cultivation in vitro. Recently, however, it has also been shown to be triggered prematurely by potentially oncogenic stimuli such as oncogene expression, oxidative stress, and DNA damage in cell culture studies. These data suggest that cellular senescence is therefore acting as a tumor-protective fail-safe mechanism. However, the significance of cellular senescence has remained an issue of debate over the years, with the possibility that it might be a cell culture-related artifact. Recent reports on oncogene-induced senescence detected in premalignant tumors have provided evidence to validate its role as a physiological response to prevent oncogenesis in vivo. In this review, we discuss the mechanisms for cellular senescence and its roles in vivo.
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Affiliation(s)
- Naoko Ohtani
- Division of Cancer Biology, The Cancer Institute, Japanese Foundation for Cancer Research, Tokyo, Japan.
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Metzger DE, Stahlman MT, Shannon JM. Misexpression of ELF5 disrupts lung branching and inhibits epithelial differentiation. Dev Biol 2008; 320:149-60. [PMID: 18544451 DOI: 10.1016/j.ydbio.2008.04.038] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2007] [Revised: 04/29/2008] [Accepted: 04/30/2008] [Indexed: 12/30/2022]
Abstract
ELF5, an Ets family transcription factor found exclusively in epithelial cells, is expressed in the distal lung epithelium during embryogenesis, then becomes restricted to proximal airways at the end of gestation and postnatally. To test the hypothesis that ELF5 represses distal epithelial differentiation, we generated a transgenic mouse model in which a doxycycline inducible HA-tagged mouse Elf5 transgene was placed under the control of the lung epithelium-specific human SFTPC promoter. We found that expressing high levels of ELF5 during early lung development disrupted branching morphogenesis and produced a dilated epithelium. The effects of ELF5 on morphogenesis were stage-dependent, since inducing the transgene on E16.5 had no effect on branching. ELF5 reduced expression of the distal lung epithelial differentiation markers Erm, Napsa and Sftpc, and type II cell ultrastructural differentiation was immature. ELF5 overexpression did not induce the proximal airway epithelial markers Ccsp and Foxj1, but did induce expression of p63, a marker of basal cells in the trachea and esophagus. High ELF5 levels also induced the expression of genes found in other endodermal epithelia but not normally associated with the lung. These results suggest that precise levels of ELF5 regulate the specification and differentiation of epithelial cells in the lung.
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Affiliation(s)
- David E Metzger
- Division of Pulmonary Biology, Cincinnati Children's Hosptial Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45229-3039, USA
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