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Chrysanthou S, Flores JC, Dawlaty MM. Tet1 Suppresses p21 to Ensure Proper Cell Cycle Progression in Embryonic Stem Cells. Cells 2022; 11:1366. [PMID: 35456045 PMCID: PMC9025953 DOI: 10.3390/cells11081366] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 04/13/2022] [Accepted: 04/14/2022] [Indexed: 12/19/2022] Open
Abstract
Ten eleven translocation 1 (Tet1) is a DNA dioxygenase that promotes DNA demethylation by oxidizing 5-methylcytosine. It can also partner with chromatin-activating and repressive complexes to regulate gene expressions independent of its enzymatic activity. Tet1 is highly expressed in embryonic stem cells (ESCs) and regulates pluripotency and differentiation. However, its roles in ESC cell cycle progression and proliferation have not been investigated. Using a series of Tet1 catalytic mutant (Tet1m/m), knockout (Tet1-/-) and wild type (Tet1+/+) mouse ESCs (mESCs), we identified a non-catalytic role of Tet1 in the proper cell cycle progression and proliferation of mESCs. Tet1-/-, but not Tet1m/m, mESCs exhibited a significant reduction in proliferation and delayed progression through G1. We found that the cyclin-dependent kinase inhibitor p21/Cdkn1a was uniquely upregulated in Tet1-/- mESCs and its knockdown corrected the slow proliferation and delayed G1 progression. Mechanistically, we found that p21 was a direct target of Tet1. Tet1 occupancy at the p21 promoter overlapped with the repressive histone mark H3K27me3 as well as with the H3K27 trimethyl transferase PRC2 component Ezh2. A loss of Tet1, but not loss of its catalytic activity, significantly reduced the enrichment of Ezh2 and H3K27 trimethylation at the p21 promoter without affecting the DNA methylation levels. We also found that the proliferation defects of Tet1-/- mESCs were independent of their differentiation defects. Together, these findings established a non-catalytic role for Tet1 in suppressing p21 in mESCs to ensure a rapid G1-to-S progression, which is a key hallmark of ESC proliferation. It also established Tet1 as an epigenetic regulator of ESC proliferation in addition to its previously defined roles in ESC pluripotency and differentiation.
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Affiliation(s)
- Stephanie Chrysanthou
- Ruth L. and David S. Gottesman Institute for Stem Cell and Regenerative Medicine Research, Albert Einstein College of Medicine, 1301 Morris Park Ave, Bronx, NY 10461, USA; (S.C.); (J.C.F.)
- Department of Genetics, Albert Einstein College of Medicine, 1301 Morris Park Ave, Bronx, NY 10461, USA
- Department of Developmental & Molecular Biology, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx, NY 10461, USA
| | - Julio C. Flores
- Ruth L. and David S. Gottesman Institute for Stem Cell and Regenerative Medicine Research, Albert Einstein College of Medicine, 1301 Morris Park Ave, Bronx, NY 10461, USA; (S.C.); (J.C.F.)
- Department of Genetics, Albert Einstein College of Medicine, 1301 Morris Park Ave, Bronx, NY 10461, USA
- Department of Developmental & Molecular Biology, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx, NY 10461, USA
| | - Meelad M. Dawlaty
- Ruth L. and David S. Gottesman Institute for Stem Cell and Regenerative Medicine Research, Albert Einstein College of Medicine, 1301 Morris Park Ave, Bronx, NY 10461, USA; (S.C.); (J.C.F.)
- Department of Genetics, Albert Einstein College of Medicine, 1301 Morris Park Ave, Bronx, NY 10461, USA
- Department of Developmental & Molecular Biology, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx, NY 10461, USA
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Metwally NH, Mohamed MS, Deeb EA. Synthesis, anticancer evaluation, CDK2 inhibition, and apoptotic activity assessment with molecular docking modeling of new class of pyrazolo[1,5-a]pyrimidines. RESEARCH ON CHEMICAL INTERMEDIATES 2021. [DOI: 10.1007/s11164-021-04564-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Li H, Guo A, Xie Z, Tu W, Yu J, Wang H, Zhao J, Zhong C, Kang J, Li J, Huang S, Shen L. Stabilization of mouse haploid embryonic stem cells with combined kinase and signal modulation. Sci Rep 2017; 7:13222. [PMID: 29038567 PMCID: PMC5643530 DOI: 10.1038/s41598-017-13471-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 09/22/2017] [Indexed: 12/19/2022] Open
Abstract
Mammalian haploid embryonic stem cells (haESCs) provide new possibilities for large-scale genetic screens because they bear only one copy of each chromosome. However, haESCs are prone to spontaneous diploidization through unknown mechanisms. Here, we report that a small molecule combination could restrain mouse haESCs from diploidization by impeding exit from naïve pluripotency and by shortening the S-G2/M phases. Combined with 2i and PD166285, our chemical cocktail could maintain haESCs in the haploid state for at least five weeks without fluorescence-activated cell sorting (FACS) enrichment of haploid cells. Taken together, we established an effective chemical approach for long-term maintenance of haESCs, and highlighted that proper cell cycle progression was critical for the maintenance of haploid state.
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Affiliation(s)
- Haisen Li
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell biology, Chinese Academy of Sciences, Shanghai, 200031, China.,Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis, and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health, Bethesda, Maryland, 20892, USA
| | - Ao Guo
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell biology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Zhenfei Xie
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell biology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Wanzhi Tu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Jiali Yu
- Life Sciences Institute, Zhejiang University, Hangzhou, 310000, China
| | - Huihan Wang
- Life Sciences Institute, Zhejiang University, Hangzhou, 310000, China
| | - Jian Zhao
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell biology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Cuiqing Zhong
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell biology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Jiuhong Kang
- Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, Shanghai, 200092, China
| | - Jinsong Li
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell biology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Shichao Huang
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell biology, Chinese Academy of Sciences, Shanghai, 200031, China. .,Shanghai Key Laboratory of Signaling and Disease Research, Laboratory of Receptor-based Bio-medicine, School of Life Sciences and Technology, Tongji University, Shanghai, 200092, China.
| | - Li Shen
- Life Sciences Institute, Zhejiang University, Hangzhou, 310000, China.
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Enrichment of G2/M cell cycle phase in human pluripotent stem cells enhances HDR-mediated gene repair with customizable endonucleases. Sci Rep 2016; 6:21264. [PMID: 26887909 PMCID: PMC4757933 DOI: 10.1038/srep21264] [Citation(s) in RCA: 127] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 01/15/2016] [Indexed: 12/23/2022] Open
Abstract
Efficient gene editing is essential to fully utilize human pluripotent stem cells (hPSCs) in regenerative medicine. Custom endonuclease-based gene targeting involves two mechanisms of DNA repair: homology directed repair (HDR) and non-homologous end joining (NHEJ). HDR is the preferred mechanism for common applications such knock-in, knock-out or precise mutagenesis, but remains inefficient in hPSCs. Here, we demonstrate that synchronizing synchronizing hPSCs in G2/M with ABT phase increases on-target gene editing, defined as correct targeting cassette integration, 3 to 6 fold. We observed improved efficiency using ZFNs, TALENs, two CRISPR/Cas9, and CRISPR/Cas9 nickase to target five genes in three hPSC lines: three human embryonic stem cell lines, neural progenitors and diabetic iPSCs. neural progenitors and diabetic iPSCs. Reversible synchronization has no effect on pluripotency or differentiation. The increase in on-target gene editing is locus-independent and specific to the cell cycle phase as G2/M phase enriched cells show a 6-fold increase in targeting efficiency compared to cells in G1 phase. Concurrently inhibiting NHEJ with SCR7 does not increase HDR or improve gene targeting efficiency further, indicating that HR is the major DNA repair mechanism after G2/M phase arrest. The approach outlined here makes gene editing in hPSCs a more viable tool for disease modeling, regenerative medicine and cell-based therapies.
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El-Badawy A, El-Badri N. The cell cycle as a brake for β-cell regeneration from embryonic stem cells. Stem Cell Res Ther 2016; 7:9. [PMID: 26759123 PMCID: PMC4711007 DOI: 10.1186/s13287-015-0274-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The generation of insulin-producing β cells from stem cells in vitro provides a promising source of cells for cell transplantation therapy in diabetes. However, insulin-producing cells generated from human stem cells show deficiency in many functional characteristics compared with pancreatic β cells. Recent reports have shown molecular ties between the cell cycle and the differentiation mechanism of embryonic stem (ES) cells, assuming that cell fate decisions are controlled by the cell cycle machinery. Both β cells and ES cells possess unique cell cycle machinery yet with significant contrasts. In this review, we compare the cell cycle control mechanisms in both ES cells and β cells, and highlight the fundamental differences between pluripotent cells of embryonic origin and differentiated β cells. Through critical analysis of the differences of the cell cycle between these two cell types, we propose that the cell cycle of ES cells may act as a brake for β-cell regeneration. Based on these differences, we discuss the potential of modulating the cell cycle of ES cells for the large-scale generation of functionally mature β cells in vitro. Further understanding of the factors that modulate the ES cell cycle will lead to new approaches to enhance the production of functional mature insulin-producing cells, and yield a reliable system to generate bona fide β cells in vitro.
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Affiliation(s)
- Ahmed El-Badawy
- Center of Excellence for Stem Cells and Regenerative Medicine (CESC), Zewail City of Science and Technology, Sheikh Zayed District, 12588, 6th of October City, Giza, Egypt
| | - Nagwa El-Badri
- Center of Excellence for Stem Cells and Regenerative Medicine (CESC), Zewail City of Science and Technology, Sheikh Zayed District, 12588, 6th of October City, Giza, Egypt.
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Peretz Y, Wu H, Patel S, Bellacosa A, Katz RA. Inhibitor of DNA Binding 4 (ID4) is highly expressed in human melanoma tissues and may function to restrict normal differentiation of melanoma cells. PLoS One 2015; 10:e0116839. [PMID: 25642713 PMCID: PMC4314081 DOI: 10.1371/journal.pone.0116839] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2014] [Accepted: 12/15/2014] [Indexed: 12/27/2022] Open
Abstract
Melanoma tissues and cell lines are heterogeneous, and include cells with invasive, proliferative, stem cell-like, and differentiated properties. Such heterogeneity likely contributes to the aggressiveness of the disease and resistance to therapy. One model suggests that heterogeneity arises from rare cancer stem cells (CSCs) that produce distinct cancer cell lineages. Another model suggests that heterogeneity arises through reversible cellular plasticity, or phenotype-switching. Recent work indicates that phenotype-switching may include the ability of cancer cells to dedifferentiate to a stem cell-like state. We set out to investigate the phenotype-switching capabilities of melanoma cells, and used unbiased methods to identify genes that may control such switching. We developed a system to reversibly synchronize melanoma cells between 2D-monolayer and 3D-stem cell-like growth states. Melanoma cells maintained in the stem cell-like state showed a striking upregulation of a gene set related to development and neural stem cell biology, which included SRY-box 2 (SOX2) and Inhibitor of DNA Binding 4 (ID4). A gene set related to cancer cell motility and invasiveness was concomitantly downregulated. Intense and pervasive ID4 protein expression was detected in human melanoma tissue samples, suggesting disease relevance for this protein. SiRNA knockdown of ID4 inhibited switching from monolayer to 3D-stem cell-like growth, and instead promoted switching to a highly differentiated, neuronal-like morphology. We suggest that ID4 is upregulated in melanoma as part of a stem cell-like program that facilitates further adaptive plasticity. ID4 may contribute to disease by preventing stem cell-like melanoma cells from progressing to a normal differentiated state. This interpretation is guided by the known role of ID4 as a differentiation inhibitor during normal development. The melanoma stem cell-like state may be protected by factors such as ID4, thereby potentially identifying a new therapeutic vulnerability to drive differentiation to the normal cell phenotype.
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Affiliation(s)
- Yuval Peretz
- Fox Chase Cancer Center, Temple University Health System, Philadelphia, Pennsylvania, United States of America
| | - Hong Wu
- Fox Chase Cancer Center, Temple University Health System, Philadelphia, Pennsylvania, United States of America
| | - Shayan Patel
- Fox Chase Cancer Center, Temple University Health System, Philadelphia, Pennsylvania, United States of America
| | - Alfonso Bellacosa
- Fox Chase Cancer Center, Temple University Health System, Philadelphia, Pennsylvania, United States of America
| | - Richard A. Katz
- Fox Chase Cancer Center, Temple University Health System, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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7
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García CP, Videla Richardson GA, Romorini L, Miriuka SG, Sevlever GE, Scassa ME. Topoisomerase I inhibitor, camptothecin, induces apoptogenic signaling in human embryonic stem cells. Stem Cell Res 2013; 12:400-14. [PMID: 24380814 DOI: 10.1016/j.scr.2013.12.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 11/27/2013] [Accepted: 12/04/2013] [Indexed: 01/10/2023] Open
Abstract
Embryonic stem cells (ESCs) need to maintain their genomic integrity in response to DNA damage to safeguard the integrity of the organism. DNA double strand breaks (DSBs) are one of the most lethal forms of DNA damage and, if not repaired correctly, they can lead to cell death, genomic instability and cancer. How human ESCs (hESCs) maintain genomic integrity in response to agents that cause DSBs is relatively unclear. In the present study we aim to determine the hESC response to the DSB inducing agent camptothecin (CPT). We find that hESCs are hypersensitive to CPT, as evidenced by high levels of apoptosis. CPT treatment leads to DNA-damage sensor kinase (ATM and DNA-PKcs) phosphorylation on serine 1981 and serine 2056, respectively. Activation of ATM and DNA-PKcs was followed by histone H2AX phosphorylation on Ser 139, a sensitive reporter of DNA damage. Nuclear accumulation and ATM-dependent phosphorylation of p53 on serine 15 were also observed. Remarkably, hESC viability was further decreased when ATM or DNA-PKcs kinase activity was impaired by the use of specific inhibitors. The hypersensitivity to CPT treatment was markedly reduced by blocking p53 translocation to mitochondria with pifithrin-μ. Importantly, programmed cell death was achieved in the absence of the cyclin dependent kinase inhibitor, p21(Waf1), a bona fide p53 target gene. Conversely, differentiated hESCs were no longer highly sensitive to CPT. This attenuated apoptotic response was accompanied by changes in cell cycle profile and by the presence of p21(Waf1). The results presented here suggest that p53 has a key involvement in preventing the propagation of damaged hESCs when genome is threatened. As a whole, our findings support the concept that the phenomenon of apoptosis is a prominent player in normal embryonic development.
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Affiliation(s)
- Carolina Paola García
- Laboratorio de Investigación aplicada a Neurociencias-LIAN-Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia-FLENI, Ruta 9, Km 52.5, B1625XAF Escobar, Provincia de Buenos Aires, Argentina.
| | - Guillermo Agustín Videla Richardson
- Laboratorio de Investigación aplicada a Neurociencias-LIAN-Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia-FLENI, Ruta 9, Km 52.5, B1625XAF Escobar, Provincia de Buenos Aires, Argentina.
| | - Leonardo Romorini
- Laboratorio de Investigación aplicada a Neurociencias-LIAN-Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia-FLENI, Ruta 9, Km 52.5, B1625XAF Escobar, Provincia de Buenos Aires, Argentina.
| | - Santiago Gabriel Miriuka
- Laboratorio de Investigación aplicada a Neurociencias-LIAN-Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia-FLENI, Ruta 9, Km 52.5, B1625XAF Escobar, Provincia de Buenos Aires, Argentina.
| | - Gustavo Emilio Sevlever
- Laboratorio de Investigación aplicada a Neurociencias-LIAN-Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia-FLENI, Ruta 9, Km 52.5, B1625XAF Escobar, Provincia de Buenos Aires, Argentina.
| | - María Elida Scassa
- Laboratorio de Investigación aplicada a Neurociencias-LIAN-Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia-FLENI, Ruta 9, Km 52.5, B1625XAF Escobar, Provincia de Buenos Aires, Argentina.
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Brown KE, Bagci H, Soza-Ried J, Fisher AG. Atypical heterochromatin organization and replication are rapidly acquired by somatic cells following fusion-mediated reprogramming by mouse ESCs. Cell Cycle 2013; 12:3253-61. [PMID: 24036550 DOI: 10.4161/cc.26223] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
We recently reported that mouse embryonic stem cells (ESCs) in S/G 2 are more efficient at reprogramming somatic cells than ESCs at other stages of the cell cycle. We also provided evidence that DNA replication is induced in the nuclei of somatic partners upon fusion with ESC partners, and showed that this was critical for their conversion toward a pluripotent state. (1) Here we have used counterflow centrifugal elutriation to enrich for ESCs at different cell cycle phases, so as to examine in detail the properties of S/G 2 phase cells. This revealed that the replication and organization of DAPI-intense heterochromatin in ESCs is unusual in two respects. First, replication of heterochromatin occurred earlier during S phase and was associated with precocious H3S10 phosphorylation. Second, heterochromatin protein 1 α (HP1α), which invariably marks DAPI-intense and H3K9me3-enriched pericentromeric domains in mouse somatic cells, (2) was not necessarily associated with these H3K9me3-enriched domains in undifferentiated ESCs. These data, which complement recent replication timing (3) and electron spectroscopic imaging (ESI) analyses, (4) suggest that heterochromatin is atypical in ESCs. Interestingly, as these unusual features were rapidly acquired by somatic nuclei upon ESC fusion-mediated reprogramming, our results suggest that fundamental changes in cell cycle structure and heterochromatin dynamics may be important for conferring pluripotency.
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Affiliation(s)
- Karen E Brown
- Lymphocyte Development Group; MRC Clinical Sciences Centre; Imperial College London; London, UK
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Barta T, Dolezalova D, Holubcova Z, Hampl A. Cell cycle regulation in human embryonic stem cells: links to adaptation to cell culture. Exp Biol Med (Maywood) 2013; 238:271-5. [PMID: 23598972 DOI: 10.1177/1535370213480711] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Cell cycle represents not only a tightly orchestrated mechanism of cell replication and cell division but it also plays an important role in regulation of cell fate decision. Particularly in the context of pluripotent stem cells or multipotent progenitor cells, regulation of cell fate decision is of paramount importance. It has been shown that human embryonic stem cells (hESCs) show unique cell cycle characteristics, such as short doubling time due to abbreviated G1 phase; these properties change with the onset of differentiation. This review summarizes the current understanding of cell cycle regulation in hESCs. We discuss cell cycle properties as well as regulatory machinery governing cell cycle progression of undifferentiated hESCs. Additionally, we provide evidence that long-term culture of hESCs is accompanied by changes in cell cycle properties as well as configuration of several cell cycle regulatory molecules.
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Affiliation(s)
- Tomas Barta
- Department of Histology and Embryology, Faculty of Medicine, Masaryk University, Kamenice 3, Brno 62500, Czech Republic.
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Tsubouchi T, Soza-Ried J, Brown K, Piccolo FM, Cantone I, Landeira D, Bagci H, Hochegger H, Merkenschlager M, Fisher AG. DNA synthesis is required for reprogramming mediated by stem cell fusion. Cell 2013; 152:873-83. [PMID: 23415233 PMCID: PMC3605571 DOI: 10.1016/j.cell.2013.01.012] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2011] [Revised: 02/14/2012] [Accepted: 01/07/2013] [Indexed: 01/09/2023]
Abstract
Embryonic stem cells (ESCs) can instruct the conversion of differentiated cells toward pluripotency following cell-to-cell fusion by a mechanism that is rapid but poorly understood. Here, we used centrifugal elutriation to enrich for mouse ESCs at sequential stages of the cell cycle and showed that ESCs in S/G2 phases have an enhanced capacity to dominantly reprogram lymphocytes and fibroblasts in heterokaryon and hybrid assays. Reprogramming success was associated with an ability to induce precocious nucleotide incorporation within the somatic partner nuclei in heterokaryons. BrdU pulse-labeling experiments revealed that virtually all successfully reprogrammed somatic nuclei, identified on the basis of Oct4 re-expression, had undergone DNA synthesis within 24 hr of fusion with ESCs. This was essential for successful reprogramming because drugs that inhibited DNA polymerase activity effectively blocked pluripotent conversion. These data indicate that nucleotide incorporation is an early and critical event in the epigenetic reprogramming of somatic cells in experimental ESC-heterokaryons.
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Affiliation(s)
- Tomomi Tsubouchi
- Lymphocyte Development Group, MRC Clinical Sciences Centre, Imperial College London, Du Cane Road, London W12 0NN, UK
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Chichinadze K, Lazarashvili A, Tkemaladze J. RNA in centrosomes: structure and possible functions. PROTOPLASMA 2013; 250:397-405. [PMID: 22684578 DOI: 10.1007/s00709-012-0422-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Accepted: 05/22/2012] [Indexed: 06/01/2023]
Abstract
A novel RNA was detected in the centrosomes of Spisula solidissima mollusk oocytes in 2006. This RNA was named centrosomal RNA (cnRNA); five different cnRNAs were described. During the sequencing of the first transcript, cnRNA 11, it was discovered that the transcript contained a conserved structure--a reverse transcriptase domain. In a 2005 study, we speculated about several possible mechanisms for determining the most important functions of centrosomal structures and referred to one of them as an "RNA-dependent mechanism". The discovery of RNA specific to the centrosome is indirect evidence of the centrosomal hypothesis of cellular aging and differentiation. The presence of a reverse transcriptase domain in this type of RNA, together with its uniqueness and specificity, makes the centrosome a place of information storage and reproduction.
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Affiliation(s)
- Konstantin Chichinadze
- I. Beritashvili Center Experimental Biomedicine, 14 Gotua Street, 0160, Tbilisi, Georgia.
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Kapinas K, Grandy R, Ghule P, Medina R, Becker K, Pardee A, Zaidi SK, Lian J, Stein J, van Wijnen A, Stein G. The abbreviated pluripotent cell cycle. J Cell Physiol 2013; 228:9-20. [PMID: 22552993 PMCID: PMC3667593 DOI: 10.1002/jcp.24104] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Human embryonic stem cells (hESCs) and induced pluripotent stem cells proliferate rapidly and divide symmetrically producing equivalent progeny cells. In contrast, lineage committed cells acquire an extended symmetrical cell cycle. Self-renewal of tissue-specific stem cells is sustained by asymmetric cell division where one progeny cell remains a progenitor while the partner progeny cell exits the cell cycle and differentiates. There are three principal contexts for considering the operation and regulation of the pluripotent cell cycle: temporal, regulatory, and structural. The primary temporal context that the pluripotent self-renewal cell cycle of hESCs is a short G1 period without reducing periods of time allocated to S phase, G2, and mitosis. The rules that govern proliferation in hESCs remain to be comprehensively established. However, several lines of evidence suggest a key role for the naïve transcriptome of hESCs, which is competent to stringently regulate the embryonic stem cell (ESC) cell cycle. This supports the requirements of pluripotent cells to self-propagate while suppressing expression of genes that confer lineage commitment and/or tissue specificity. However, for the first time, we consider unique dimensions to the architectural organization and assembly of regulatory machinery for gene expression in nuclear microenviornments that define parameters of pluripotency. From both fundamental biological and clinical perspectives, understanding control of the abbreviated ESC cycle can provide options to coordinate control of proliferation versus differentiation. Wound healing, tissue engineering, and cell-based therapy to mitigate developmental aberrations illustrate applications that benefit from knowledge of the biology of the pluripotent cell cycle.
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Affiliation(s)
- Kristina Kapinas
- Department of Cell Biology, University of Massachusetts Medical School, Worcester, MA 01655
| | - Rodrigo Grandy
- Department of Cell Biology, University of Massachusetts Medical School, Worcester, MA 01655
| | - Prachi Ghule
- Department of Cell Biology, University of Massachusetts Medical School, Worcester, MA 01655
| | - Ricardo Medina
- Department of Cell Biology, University of Massachusetts Medical School, Worcester, MA 01655
| | - Klaus Becker
- Department of Cell Biology, University of Massachusetts Medical School, Worcester, MA 01655
| | - Arthur Pardee
- Department of Biological Chemistry and Molecular Pharmacology, Dana-Farber Cancer Institute, Boston, MA 02215
| | - Sayyed K. Zaidi
- Department of Cell Biology, University of Massachusetts Medical School, Worcester, MA 01655
| | - Jane Lian
- Department of Cell Biology, University of Massachusetts Medical School, Worcester, MA 01655
| | - Janet Stein
- Department of Cell Biology, University of Massachusetts Medical School, Worcester, MA 01655
| | - Andre van Wijnen
- Department of Cell Biology, University of Massachusetts Medical School, Worcester, MA 01655
| | - Gary Stein
- Department of Cell Biology, University of Massachusetts Medical School, Worcester, MA 01655
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Vidigal JA, Ventura A. Embryonic stem cell miRNAs and their roles in development and disease. Semin Cancer Biol 2012; 22:428-36. [PMID: 22561239 DOI: 10.1016/j.semcancer.2012.04.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Accepted: 04/17/2012] [Indexed: 01/07/2023]
Abstract
MicroRNAs have emerged as important modulators of gene expression. Both during development and disease, regulation by miRNAs controls the choice between self-renewal and differentiation, survival and apoptosis and dictates how cells respond to external stimuli. In mouse pluripotent embryonic stem cells, a surprisingly small set of miRNAs, encoded by four polycistronic genes is at the center of such decisions. miR-290-295, miR-302-367, miR-17-92 and miR-106b-25 encode for miRNAs with highly related sequences that seem to control largely overlapping gene sets. Recent studies have highlighted the importance of these miRNAs in the maintenance of 'stemness' and regulation of normal development and have linked the deregulation of their expression to a variety of human diseases.
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Affiliation(s)
- Joana Alves Vidigal
- Memorial Sloan-Kettering Cancer Center, Cancer Biology and Genetics Program, New York, NY 10065, United States
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Transcriptome analysis reveals strain-specific and conserved stemness genes in Schmidtea mediterranea. PLoS One 2012; 7:e34447. [PMID: 22496805 PMCID: PMC3319590 DOI: 10.1371/journal.pone.0034447] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Accepted: 03/05/2012] [Indexed: 02/06/2023] Open
Abstract
The planarian Schmidtea mediterranea is a powerful model organism for studying stem cell biology due to its extraordinary regenerative ability mediated by neoblasts, a population of adult somatic stem cells. Elucidation of the S. mediterranea transcriptome and the dynamics of transcript expression will increase our understanding of the gene regulatory programs that regulate stem cell function and differentiation. Here, we have used RNA-Seq to characterize the S. mediterranea transcriptome in sexual and asexual animals and in purified neoblast and differentiated cell populations. Our analysis identified many uncharacterized genes, transcripts, and alternatively spliced isoforms that are differentially expressed in a strain or cell type-specific manner. Transcriptome profiling of purified neoblasts and differentiated cells identified neoblast-enriched transcripts, many of which likely play important roles in regeneration and stem cell function. Strikingly, many of the neoblast-enriched genes are orthologs of genes whose expression is enriched in human embryonic stem cells, suggesting that a core set of genes that regulate stem cell function are conserved across metazoan species.
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Wong DTW, Kim JJ, Khalid O, Sun HH, Kim Y. Double edge: CDK2AP1 in cell-cycle regulation and epigenetic regulation. J Dent Res 2011; 91:235-41. [PMID: 21865592 DOI: 10.1177/0022034511420723] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Cancer research has been devoted toward an understanding of the molecular regulation and functional significance of cell-cycle regulators in the pathogenesis and development of cancers. Cyclin-dependent Kinase 2-associated Protein 1 (CDK2AP1) is one such cell-cycle regulator, originally identified as a growth suppressor and a prognostic marker for human oral/head and neck cancers. Functional importance and the molecular mechanism of CDK2AP1-mediated cell-cycle regulation have been documented over the years. Recent progress has shown that CDK2AP1 is a competency factor in embryonic stem cell differentiation. Deletion of CDK2AP1 leads to early embryonic lethality, potentially through altered differentiation capability of embryonic stem cells. More intriguingly, CDK2AP1 exerts its effect on stem cell maintenance/differentiation through epigenetic regulation. Cancer cells and stem cells share common cellular characteristics, most prominently in maintaining high proliferative potential through an unconventional cell-cycle regulatory mechanism. Cross-talk between cellular processes and molecular signaling pathways is frequent in any biological system. Currently, it remains largely elusive how cell-cycle regulation is mechanistically linked to epigenetic control. Understanding the molecular mechanism underlying CDK2AP1-mediated cell-cycle regulation and epigenetic control will set an example for establishing a novel and effective molecular link between these two important regulatory mechanisms.
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Affiliation(s)
- D T W Wong
- UCLA School of Dentistry and Dental Research Institute, 10833 Le Conte Ave., 73-017 CHS, Los Angeles, CA 90095, USA
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