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Geng Y, Liu P, Xie Y, Liu Y, Zhang X, Hou X, Zhang L. Xanthatin suppresses pancreatic cancer cell growth via the ROS/RBL1 signaling pathway: In vitro and in vivo insights. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2023; 119:155004. [PMID: 37562091 DOI: 10.1016/j.phymed.2023.155004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 07/06/2023] [Accepted: 07/28/2023] [Indexed: 08/12/2023]
Abstract
BACKGROUND As a malignant digestive system tumor, pancreatic cancer has a high mortality rate. Xanthatin is a sesquiterpene lactone monomer compound purified from the traditional Chinese herb Xanthium strumarium L. It has been reported that Xanthatin exhibits inhibitory effects on various cancer cells in retinoblastoma, glioma, hepatoma, colon cancer, lung cancer, as well as breast cancer. However, in pancreatic cancer cells, only one report exists on the suppression of Prostaglandin E2 synthesis and the induction of caspase 3/7 activation in Xanthatin-treated MIA PaCa-2 cells, while systematic in vitro and in vivo investigations and related mechanisms have yet to be explored. PURPOSE This research aims to explore the in vitro and in vivo effects of Xanthatin on pancreatic cancer and its molecular mechanisms. METHODS The anticancer effects and mechanisms of Xanthatin on pancreatic cancer cells were assessed through employing cell counting kit-8 (CCK-8) assay, lactate dehydrogenase (LDH) assay, carboxyfluorescein diacetate succinimidyl ester (CFDA SE) cell proliferation assay, colony formation assay, wound healing assay, transwell assay, Annexin V-FITC/propidium iodide (PI) dual staining, Hoechst nuclear staining, Western blot analysis, phosphoproteomics, and reactive oxygen species (ROS) measurement. The in vivo anticancer effects of Xanthatin on pancreatic cancer cells were studied using a nude mouse model. RESULTS The present study showed that Xanthatin can prevent the proliferation and metastasis of pancreatic cancer cells and trigger the exposure of phosphatidylserine (PS), chromatin condensation, and caspase activation, thereby inducing apoptosis. Phosphoproteomic analysis indicated that Xanthatin inhibits the phosphorylation of the proliferation-associated protein RBL1, and oxidative stress can lead to RBL1 dephosphorylation. Further investigation revealed that Xanthatin significantly upregulates ROS levels in pancreatic cancer cells, and the antioxidant N-acetylcysteine (NAC) can reverse Xanthatin-induced cell proliferation inhibition and apoptosis. In addition, Xanthatin can suppress pancreatic cancer cell growth in a xenograft nude mouse model with low toxicity to the mice. CONCLUSION Xanthatin may inhibit the proliferation of pancreatic cancer cells and trigger apoptosis through the ROS/RBL1 signaling pathway.
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Affiliation(s)
- Yadi Geng
- Department of Pharmacy, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230001, China; Department of Pharmacy, Anhui Provincial Hospital, Anhui Medical University, Hefei, Anhui, 230001, China
| | - Ping Liu
- Institute of Clinical Pharmacology, Anhui Medical University, Hefei, Anhui, 230032, China
| | - Yanbo Xie
- Department of Pharmacy, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230001, China
| | - Yunxiao Liu
- Institute of Clinical Pharmacology, Anhui Medical University, Hefei, Anhui, 230032, China
| | - Xinge Zhang
- Institute of Clinical Pharmacology, Anhui Medical University, Hefei, Anhui, 230032, China
| | - Xingcun Hou
- School of Pharmacy, Anhui Medical University, Hefei, Anhui, 230032, China
| | - Lei Zhang
- Department of Pharmacy, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230001, China; Department of Pharmacy, Anhui Provincial Hospital, Anhui Medical University, Hefei, Anhui, 230001, China; Institute of Clinical Pharmacology, Anhui Medical University, Hefei, Anhui, 230032, China.
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Raicu AM, Castanheira P, Arnosti DN. Retinoblastoma protein activity revealed by CRISPRi study of divergent Rbf1 and Rbf2 paralogs. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.19.541454. [PMID: 37293052 PMCID: PMC10245722 DOI: 10.1101/2023.05.19.541454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Retinoblastoma tumor suppressor proteins regulate the key transition from G1 to S phase of the cell cycle. The mammalian Rb family comprises Rb, p107, and p130, with overlapping and unique roles in gene regulation. Drosophila experienced an independent gene duplication event, leading to the Rbf1 and Rbf2 paralogs. To uncover the significance of paralogy in the Rb family, we used CRISPRi. We engineered dCas9 fusions to Rbf1 and Rbf2, and deployed them to gene promoters in developing Drosophila tissue to study their relative impacts on gene expression. On some genes, both Rbf1 and Rbf2 mediate potent repression, in a highly distance-dependent manner. In other cases, the two proteins have different effects on phenotype and gene expression, indicating different functional potential. In a direct comparison of Rb activity on endogenous genes and transiently transfected reporters, we found that only qualitative, but not key quantitative aspects of repression were conserved, indicating that the native chromatin environment generates context-specific effects of Rb activity. Our study uncovers the complexity of Rb-mediated transcriptional regulation in a living organism, which is clearly impacted by the different promoter landscapes and the evolution of the Rb proteins themselves.
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Affiliation(s)
- Ana-Maria Raicu
- Cell and Molecular Biology Program, Michigan State University, East Lansing, MI
| | - Patricia Castanheira
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI
| | - David N Arnosti
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI
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Zappia M, Kwon YJ, Westacott A, Liseth I, Lee H, Islam ABMMK, Kim J, Frolov M. E2F regulation of the Phosphoglycerate kinase gene is functionally important in Drosophila development. Proc Natl Acad Sci U S A 2023; 120:e2220770120. [PMID: 37011211 PMCID: PMC10104548 DOI: 10.1073/pnas.2220770120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 03/03/2023] [Indexed: 04/05/2023] Open
Abstract
The canonical role of the transcription factor E2F is to control the expression of cell cycle genes by binding to the E2F sites in their promoters. However, the list of putative E2F target genes is extensive and includes many metabolic genes, yet the significance of E2F in controlling the expression of these genes remains largely unknown. Here, we used the CRISPR/Cas9 technology to introduce point mutations in the E2F sites upstream of five endogenous metabolic genes in Drosophila melanogaster. We found that the impact of these mutations on both the recruitment of E2F and the expression of the target genes varied, with the glycolytic gene, Phosphoglycerate kinase (Pgk), being mostly affected. The loss of E2F regulation on the Pgk gene led to a decrease in glycolytic flux, tricarboxylic acid cycle intermediates levels, adenosine triphosphate (ATP) content, and an abnormal mitochondrial morphology. Remarkably, chromatin accessibility was significantly reduced at multiple genomic regions in PgkΔE2F mutants. These regions contained hundreds of genes, including metabolic genes that were downregulated in PgkΔE2F mutants. Moreover, PgkΔE2F animals had shortened life span and exhibited defects in high-energy consuming organs, such as ovaries and muscles. Collectively, our results illustrate how the pleiotropic effects on metabolism, gene expression, and development in the PgkΔE2F animals underscore the importance of E2F regulation on a single E2F target, Pgk.
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Affiliation(s)
- Maria Paula Zappia
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, IL 60607
| | - Yong-Jae Kwon
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, IL 60607
| | - Anton Westacott
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, IL 60607
| | - Isabel Liseth
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, IL 60607
| | - Hyun Min Lee
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, IL 60607
| | - Abul B. M. M. K. Islam
- Department of Genetic Engineering and Biotechnology, University of Dhaka, Dhaka1000, Bangladesh
| | - Jiyeon Kim
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, IL 60607
| | - Maxim V. Frolov
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, IL 60607
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Myers JE, Schaal DL, Nkadi EH, Ward BJH, Bienkowska-Haba M, Sapp M, Bodily JM, Scott RS. Retinoblastoma Protein Is Required for Epstein-Barr Virus Replication in Differentiated Epithelia. J Virol 2023; 97:e0103222. [PMID: 36719239 PMCID: PMC9972952 DOI: 10.1128/jvi.01032-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 12/20/2022] [Indexed: 02/01/2023] Open
Abstract
Coinfection of human papillomavirus (HPV) and Epstein-Barr virus (EBV) has been detected in oropharyngeal squamous cell carcinoma. Although HPV and EBV replicate in differentiated epithelial cells, we previously reported that HPV epithelial immortalization reduces EBV replication within organotypic raft culture and that the HPV16 oncoprotein E7 was sufficient to inhibit EBV replication. A well-established function of HPV E7 is the degradation of the retinoblastoma (Rb) family of pocket proteins (pRb, p107, and p130). Here, we show that pRb knockdown in differentiated epithelia and EBV-positive Burkitt lymphoma (BL) reduces EBV lytic replication following de novo infection and reactivation, respectively. In differentiated epithelia, EBV immediate early (IE) transactivators were expressed, but loss of pRb blocked expression of the early gene product, EA-D. Although no alterations were observed in markers of epithelial differentiation, DNA damage, and p16, increased markers of S-phase progression and altered p107 and p130 levels were observed in suprabasal keratinocytes after pRb knockdown. In contrast, pRb interference in Akata BX1 Burkitt lymphoma cells showed a distinct phenotype from differentiated epithelia with no significant effect on EBV IE or EA-D expression. Instead, pRb knockdown reduced the levels of the plasmablast differentiation marker PRDM1/Blimp1 and increased the abundance of c-Myc protein in reactivated Akata BL with pRb knockdown. c-Myc RNA levels also increased following the loss of pRb in epithelial rafts. These results suggest that pRb is required to suppress c-Myc for efficient EBV replication in BL cells and identifies a mechanism for how HPV immortalization, through degradation of the retinoblastoma pocket proteins, interferes with EBV replication in coinfected epithelia. IMPORTANCE Terminally differentiated epithelium is known to support EBV genome amplification and virion morphogenesis following infection. The contribution of the cell cycle in differentiated tissues to efficient EBV replication is not understood. Using organotypic epithelial raft cultures and genetic interference, we can identify factors required for EBV replication in quiescent cells. Here, we phenocopied HPV16 E7 inhibition of EBV replication through knockdown of pRb. Loss of pRb was found to reduce EBV early gene expression and viral replication. Interruption of the viral life cycle was accompanied by increased S-phase gene expression in postmitotic keratinocytes, a process also observed in E7-positive epithelia, and deregulation of other pocket proteins. Together, these findings provide evidence of a global requirement for pRb in EBV lytic replication and provide a mechanistic framework for how HPV E7 may facilitate a latent EBV infection through its mediated degradation of pRb in copositive epithelia.
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Affiliation(s)
- Julia E. Myers
- Department of Microbiology and Immunology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, Louisiana, USA
- Center for Molecular and Tumor Virology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, Louisiana, USA
- Feist-Weiller Cancer Center, Louisiana State University Health Sciences Center-Shreveport, Shreveport, Louisiana, USA
- Center for Applied Immunology and Pathological Processes, Louisiana State University Health Sciences Center-Shreveport, Shreveport, Louisiana, USA
| | - Danielle L. Schaal
- Department of Microbiology and Immunology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, Louisiana, USA
- Center for Molecular and Tumor Virology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, Louisiana, USA
- Feist-Weiller Cancer Center, Louisiana State University Health Sciences Center-Shreveport, Shreveport, Louisiana, USA
- Center for Applied Immunology and Pathological Processes, Louisiana State University Health Sciences Center-Shreveport, Shreveport, Louisiana, USA
| | - Ebubechukwu H. Nkadi
- Department of Microbiology and Immunology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, Louisiana, USA
- Feist-Weiller Cancer Center, Louisiana State University Health Sciences Center-Shreveport, Shreveport, Louisiana, USA
- Center for Applied Immunology and Pathological Processes, Louisiana State University Health Sciences Center-Shreveport, Shreveport, Louisiana, USA
| | - B. J. H. Ward
- Department of Microbiology and Immunology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, Louisiana, USA
- Feist-Weiller Cancer Center, Louisiana State University Health Sciences Center-Shreveport, Shreveport, Louisiana, USA
- Center for Applied Immunology and Pathological Processes, Louisiana State University Health Sciences Center-Shreveport, Shreveport, Louisiana, USA
| | - Malgorzata Bienkowska-Haba
- Department of Microbiology and Immunology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, Louisiana, USA
- Center for Applied Immunology and Pathological Processes, Louisiana State University Health Sciences Center-Shreveport, Shreveport, Louisiana, USA
| | - Martin Sapp
- Department of Microbiology and Immunology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, Louisiana, USA
- Center for Molecular and Tumor Virology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, Louisiana, USA
- Feist-Weiller Cancer Center, Louisiana State University Health Sciences Center-Shreveport, Shreveport, Louisiana, USA
- Center for Applied Immunology and Pathological Processes, Louisiana State University Health Sciences Center-Shreveport, Shreveport, Louisiana, USA
| | - Jason M. Bodily
- Department of Microbiology and Immunology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, Louisiana, USA
- Center for Molecular and Tumor Virology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, Louisiana, USA
- Feist-Weiller Cancer Center, Louisiana State University Health Sciences Center-Shreveport, Shreveport, Louisiana, USA
- Center for Applied Immunology and Pathological Processes, Louisiana State University Health Sciences Center-Shreveport, Shreveport, Louisiana, USA
| | - Rona S. Scott
- Department of Microbiology and Immunology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, Louisiana, USA
- Center for Molecular and Tumor Virology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, Louisiana, USA
- Feist-Weiller Cancer Center, Louisiana State University Health Sciences Center-Shreveport, Shreveport, Louisiana, USA
- Center for Applied Immunology and Pathological Processes, Louisiana State University Health Sciences Center-Shreveport, Shreveport, Louisiana, USA
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Zhang S, Zatulovskiy E, Arand J, Sage J, Skotheim JM. The cell cycle inhibitor RB is diluted in G1 and contributes to controlling cell size in the mouse liver. Front Cell Dev Biol 2022; 10:965595. [PMID: 36092730 PMCID: PMC9452963 DOI: 10.3389/fcell.2022.965595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 07/27/2022] [Indexed: 12/14/2022] Open
Abstract
Every type of cell in an animal maintains a specific size, which likely contributes to its ability to perform its physiological functions. While some cell size control mechanisms are beginning to be elucidated through studies of cultured cells, it is unclear if and how such mechanisms control cell size in an animal. For example, it was recently shown that RB, the retinoblastoma protein, was diluted by cell growth in G1 to promote size-dependence of the G1/S transition. However, it remains unclear to what extent the RB-dilution mechanism controls cell size in an animal. We therefore examined the contribution of RB-dilution to cell size control in the mouse liver. Consistent with the RB-dilution model, genetic perturbations decreasing RB protein concentrations through inducible shRNA expression or through liver-specific Rb1 knockout reduced hepatocyte size, while perturbations increasing RB protein concentrations in an Fah -/- mouse model increased hepatocyte size. Moreover, RB concentration reflects cell size in G1 as it is lower in larger G1 hepatocytes. In contrast, concentrations of the cell cycle activators Cyclin D1 and E2f1 were relatively constant. Lastly, loss of Rb1 weakened cell size control, i.e., reduced the inverse correlation between how much cells grew in G1 and how large they were at birth. Taken together, our results show that an RB-dilution mechanism contributes to cell size control in the mouse liver by linking cell growth to the G1/S transition.
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Affiliation(s)
- Shuyuan Zhang
- Department of Biology, Stanford University, Stanford, CA, United States
| | | | - Julia Arand
- Departments of Pediatrics and Genetics, School of Medicine, Stanford University, Stanford, CA, United States
| | - Julien Sage
- Departments of Pediatrics and Genetics, School of Medicine, Stanford University, Stanford, CA, United States
| | - Jan M. Skotheim
- Department of Biology, Stanford University, Stanford, CA, United States,Chan Zuckerberg Biohub, San Francisco, CA, United States,*Correspondence: Jan M. Skotheim,
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Guerra B, Doktor TK, Frederiksen SB, Somyajit K, Andresen BS. Essential role of CK2α for the interaction and stability of replication fork factors during DNA synthesis and activation of the S-phase checkpoint. Cell Mol Life Sci 2022; 79:339. [PMID: 35661926 PMCID: PMC9166893 DOI: 10.1007/s00018-022-04374-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 05/09/2022] [Accepted: 05/12/2022] [Indexed: 11/25/2022]
Abstract
The ataxia telangiectasia mutated and Rad3-related (ATR)-CHK1 pathway is the major signalling cascade activated in response to DNA replication stress. This pathway is associated with the core of the DNA replication machinery comprising CDC45, the replicative MCM2-7 hexamer, GINS (altogether forming the CMG complex), primase-polymerase (POLε, -α, and -δ) complex, and additional fork protection factors such as AND-1, CLASPIN (CLSPN), and TIMELESS/TIPIN. In this study, we report that functional protein kinase CK2α is critical for preserving replisome integrity and for mounting S-phase checkpoint signalling. We find that CDC45, CLSPN and MCM7 are novel CK2α interacting partners and these interactions are particularly important for maintenance of stable MCM7-CDC45, ATRIP-ATR-MCM7, and ATR-CLSPN protein complexes. Consistently, cells depleted of CK2α and treated with hydroxyurea display compromised replisome integrity, reduced chromatin binding of checkpoint mediator CLSPN, attenuated ATR-mediated S-phase checkpoint and delayed recovery of stalled forks. In further support of this, differential gene expression analysis by RNA-sequencing revealed that down-regulation of CK2α accompanies global shutdown of genes that are implicated in the S-phase checkpoint. These findings add to our understanding of the molecular mechanisms involved in DNA replication by showing that the protein kinase CK2α is essential for maintaining the stability of the replisome machinery and for optimizing ATR-CHK1 signalling activation upon replication stress.
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Affiliation(s)
- Barbara Guerra
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark.
| | - Thomas K Doktor
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Sabrina B Frederiksen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Kumar Somyajit
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Brage S Andresen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
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Mustafa N, Mitxelena J, Infante A, Zenarruzabeitia O, Eriz A, Iglesias-Ara A, Zubiaga AM. E2f2 Attenuates Apoptosis of Activated T Lymphocytes and Protects from Immune-Mediated Injury through Repression of Fas and FasL. Int J Mol Sci 2021; 23:ijms23010311. [PMID: 35008734 PMCID: PMC8745065 DOI: 10.3390/ijms23010311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 12/20/2021] [Accepted: 12/25/2021] [Indexed: 12/03/2022] Open
Abstract
Targeted disruption of E2f2 in mice causes T-cell hyperactivation and a disproportionate cell cycle entry upon stimulation. However, E2f2−/− mice do not develop a lymphoproliferative condition. We report that E2f2 plays a Fas-dependent anti-apoptotic function in vitro and in vivo. TCR-stimulated murine E2f2−/− T cells overexpress the proapoptotic genes Fas and FasL and exhibit enhanced apoptosis, which is prevented by treatment with neutralizing anti-FasL antibodies. p53 pathway is activated in TCR-stimulated E2f2−/− lymphocytes, but targeted disruption of p53 in E2f2−/− mice does not abrogate Fas/FasL expression or apoptosis, implying a p53-independent apoptotic mechanism. We show that E2f2 is recruited to Fas and FasL gene promoters to repress their expression. in vivo, E2f2−/− mice are prone to develop immune-mediated liver injury owing to an aberrant lymphoid Fas/FasL activation. Taken together, our results suggest that E2f2-dependent inhibition of Fas/FasL pathway may play a direct role in limiting the development of immune-mediated pathologies.
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Affiliation(s)
- Noor Mustafa
- Department of Genetics, Physical Anthropology and Animal Physiology, University of the Basque Country, UPV/EHU, 48080 Bilbao, Spain; (N.M.); (J.M.); (A.E.)
| | - Jone Mitxelena
- Department of Genetics, Physical Anthropology and Animal Physiology, University of the Basque Country, UPV/EHU, 48080 Bilbao, Spain; (N.M.); (J.M.); (A.E.)
- Ikerbasque, Basque Foundation for Science, 48009 Bilbao, Spain
| | - Arantza Infante
- Stem Cells and Cell Therapy Laboratory, Biocruces Bizkaia Health Research Institute, 48903 Barakaldo, Spain;
| | - Olatz Zenarruzabeitia
- Immunopathology Group, Biocruces Bizkaia Health Research Institute, 48903 Barakaldo, Spain;
| | - Ainhoa Eriz
- Department of Genetics, Physical Anthropology and Animal Physiology, University of the Basque Country, UPV/EHU, 48080 Bilbao, Spain; (N.M.); (J.M.); (A.E.)
| | - Ainhoa Iglesias-Ara
- Department of Genetics, Physical Anthropology and Animal Physiology, University of the Basque Country, UPV/EHU, 48080 Bilbao, Spain; (N.M.); (J.M.); (A.E.)
- Correspondence: (A.I.-A.); (A.M.Z.); Tel.: +34-94-601-5799 (A.I.-A.); +34-94-601-2603 (A.M.Z.); Fax: +34-94-601-3143 (A.M.Z.)
| | - Ana M. Zubiaga
- Department of Genetics, Physical Anthropology and Animal Physiology, University of the Basque Country, UPV/EHU, 48080 Bilbao, Spain; (N.M.); (J.M.); (A.E.)
- Correspondence: (A.I.-A.); (A.M.Z.); Tel.: +34-94-601-5799 (A.I.-A.); +34-94-601-2603 (A.M.Z.); Fax: +34-94-601-3143 (A.M.Z.)
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Voigt E, Wallenburg M, Wollenzien H, Thompson E, Kumar K, Feiner J, McNally M, Friesen H, Mukherjee M, Afeworki Y, Kareta MS. Sox2 Is an Oncogenic Driver of Small-Cell Lung Cancer and Promotes the Classic Neuroendocrine Subtype. Mol Cancer Res 2021; 19:2015-2025. [PMID: 34593608 PMCID: PMC8642303 DOI: 10.1158/1541-7786.mcr-20-1006] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 06/02/2021] [Accepted: 09/24/2021] [Indexed: 11/16/2022]
Abstract
Although many cancer prognoses have improved in the past 50 years due to advancements in treatments, there has been little improvement in therapies for small-cell lung cancer (SCLC). One promising avenue to improve treatment for SCLC is to understand its underlying genetic alterations that drive its formation, growth, and cellular heterogeneity. RB1 loss is one key driver of SCLC, and RB1 loss has been associated with an increase in pluripotency factors such as SOX2. SOX2 is highly expressed and amplified in SCLC and has been associated with SCLC growth. Using a genetically engineered mouse model, we have shown that Sox2 is required for efficient SCLC formation. Furthermore, genome-scale binding assays have indicated that SOX2 can regulate key SCLC pathways such as NEUROD1 and MYC. These data suggest that SOX2 can be associated with the switch of SCLC from an ASCL1 subtype to a NEUROD1 subtype. Understanding this genetic switch is key to understanding such processes as SCLC progression, cellular heterogeneity, and treatment resistance. IMPLICATIONS: Understanding the molecular mechanisms of SCLC initiation and development are key to opening new potential therapeutic options for this devastating disease.
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Affiliation(s)
- Ellen Voigt
- Cancer Biology and Immunotherapies Group, Sanford Research, Sioux Falls, South Dakota
- Genetics & Genomics Group, Sanford Research, Sioux Falls, South Dakota
| | - Madeline Wallenburg
- Cancer Biology and Immunotherapies Group, Sanford Research, Sioux Falls, South Dakota
- Genetics & Genomics Group, Sanford Research, Sioux Falls, South Dakota
| | - Hannah Wollenzien
- Cancer Biology and Immunotherapies Group, Sanford Research, Sioux Falls, South Dakota
- Genetics & Genomics Group, Sanford Research, Sioux Falls, South Dakota
- Division of Basic Biomedical Sciences, University of South Dakota, Vermillion, South Dakota
| | - Ethan Thompson
- Cancer Biology and Immunotherapies Group, Sanford Research, Sioux Falls, South Dakota
- Genetics & Genomics Group, Sanford Research, Sioux Falls, South Dakota
| | - Kirtana Kumar
- Cancer Biology and Immunotherapies Group, Sanford Research, Sioux Falls, South Dakota
- Genetics & Genomics Group, Sanford Research, Sioux Falls, South Dakota
| | | | - Moira McNally
- Cancer Biology and Immunotherapies Group, Sanford Research, Sioux Falls, South Dakota
- Genetics & Genomics Group, Sanford Research, Sioux Falls, South Dakota
| | - Hunter Friesen
- Cancer Biology and Immunotherapies Group, Sanford Research, Sioux Falls, South Dakota
- Genetics & Genomics Group, Sanford Research, Sioux Falls, South Dakota
| | - Malini Mukherjee
- Functional Genomics & Bioinformatics Core, Sanford Research, Sioux Falls, South Dakota
| | - Yohannes Afeworki
- Functional Genomics & Bioinformatics Core, Sanford Research, Sioux Falls, South Dakota
| | - Michael S Kareta
- Cancer Biology and Immunotherapies Group, Sanford Research, Sioux Falls, South Dakota.
- Genetics & Genomics Group, Sanford Research, Sioux Falls, South Dakota
- Division of Basic Biomedical Sciences, University of South Dakota, Vermillion, South Dakota
- Functional Genomics & Bioinformatics Core, Sanford Research, Sioux Falls, South Dakota
- Department of Pediatrics, Sanford School of Medicine, University of South Dakota, Sioux Falls, South Dakota
- Department of Chemistry Biochemistry, South Dakota State University, Brookings, South Dakota
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Ventura E, Iannuzzi CA, Pentimalli F, Giordano A, Morrione A. RBL1/p107 Expression Levels Are Modulated by Multiple Signaling Pathways. Cancers (Basel) 2021; 13:cancers13195025. [PMID: 34638509 PMCID: PMC8507926 DOI: 10.3390/cancers13195025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 09/29/2021] [Accepted: 10/02/2021] [Indexed: 11/16/2022] Open
Abstract
The members of the retinoblastoma (RB) protein family, RB1/p105, retinoblastoma-like (RBL)1/p107 and RBL2/p130 are critical modulators of the cell cycle and their dysregulation has been associated with tumor initiation and progression. The activity of RB proteins is regulated by numerous pathways including oncogenic signaling, but the molecular mechanisms of these functional interactions are not fully defined. We previously demonstrated that RBL2/p130 is a direct target of AKT and it is a key mediator of the apoptotic process induced by AKT inhibition. Here we demonstrated that RBL1/p107 levels are only minorly modulated by the AKT signaling pathway. In contrast, we discovered that RBL1/p107 levels are regulated by multiple pathways linked directly or indirectly to Ca2+-dependent signaling. Inhibition of the multifunctional calcium/calmodulin-dependent kinases (CaMKs) significantly reduced RBL1/p107 expression levels and phosphorylation, increased RBL1/p107 nuclear localization and led to cell cycle arrest in G0/G1. Targeting the Ca2+-dependent endopeptidase calpain stabilized RBL1/p107 levels and counteracted the reduction of RBL1/p107 levels associated with CaMKs inhibition. Thus, these novel observations suggest a complex regulation of RBL1/p107 expression involving different components of signaling pathways controlled by Ca2+ levels, including CaMKs and calpain, pointing out a significant difference with the mechanisms modulating the close family member RBL2/p130.
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Affiliation(s)
- Elisa Ventura
- Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology, College of Science and Technology, Temple University, Philadelphia, PA 19122, USA; (E.V.); (A.G.)
| | - Carmelina Antonella Iannuzzi
- Cell Biology and Biotherapy Unit, Istituto Nazionale Tumori, IRCCS, Fondazione G. Pascale, I-80131 Napoli, Italy; (C.A.I.); (F.P.)
| | - Francesca Pentimalli
- Cell Biology and Biotherapy Unit, Istituto Nazionale Tumori, IRCCS, Fondazione G. Pascale, I-80131 Napoli, Italy; (C.A.I.); (F.P.)
| | - Antonio Giordano
- Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology, College of Science and Technology, Temple University, Philadelphia, PA 19122, USA; (E.V.); (A.G.)
- Department of Medical Biotechnologies, University of Siena, I-53100 Siena, Italy
| | - Andrea Morrione
- Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology, College of Science and Technology, Temple University, Philadelphia, PA 19122, USA; (E.V.); (A.G.)
- Correspondence: ; Tel.: +215-204-2450
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Hamada H, Goto Y, Arakawa J, Murayama E, Ogawa Y, Konno M, Oyama T, Asai M, Sato A, Tanuma SI, Uchiumi F. Characterization of the human E2F4 promoter region and its response to 12-O-tetradecanoylphorbol-13-acetate. J Biochem 2019; 166:363-373. [PMID: 31199460 DOI: 10.1093/jb/mvz047] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 06/11/2019] [Indexed: 12/23/2022] Open
Abstract
The E2F transcription factors (TFs), which control the progression of the cell cycle in response to DNA-damage and various stresses, are known to interact with a tumour suppressor, Retinoblastoma 1 (RB1). We previously showed that the response of the human RB1 promoter to a 12-O-tetradecanoylphorbol-13-acetate (TPA) in HL-60 cells is mediated by a duplicated GGAA motif, which is also present in the 5'-upstream of the E2F family genes. The motifs are especially rich in the 5'-upstream of the E2F4 gene. In the present study, we constructed luciferase (Luc) expression vectors containing a 466 bp of the 5'-upstream of the human E2F4 gene. The transfection of this plasmid and deletion/mutation-introduced derivatives into HL-60 cells and a Luc reporter assay showed that duplicated and triplicated GGAA (TTCC) motifs in the E2F4 promoter respond to TPA. As expected, electrophoretic mobility shift assay indicated that SPI1 (PU.1) binds to the GGAA motif-containing element. A quantitative RT-PCR and western blotting showed that the E2F4 transcripts and its encoding proteins accumulate during the differentiation of HL-60 into macrophage-like cells. In contrast, the expression of the E2F1 gene and the protein, which possibly acts as a cell cycle accelerator, was greatly diminished.
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Affiliation(s)
- Hiroshi Hamada
- Department of Gene Regulation, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda-shi, Chiba-ken, Japan
| | - Yuta Goto
- Department of Gene Regulation, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda-shi, Chiba-ken, Japan
| | - Jun Arakawa
- Department of Gene Regulation, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda-shi, Chiba-ken, Japan
| | - Erisa Murayama
- Department of Gene Regulation, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda-shi, Chiba-ken, Japan
| | - Yui Ogawa
- Department of Gene Regulation, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda-shi, Chiba-ken, Japan
| | - Midori Konno
- Department of Gene Regulation, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda-shi, Chiba-ken, Japan
| | - Takahiro Oyama
- Hinoki Shinyaku Co., Ltd, 9-6 Nibancho, Chiyoda-ku, Tokyo, Japan
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda-shi, Chiba-ken, Japan
| | - Masashi Asai
- Department of Gene Regulation, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda-shi, Chiba-ken, Japan
| | - Akira Sato
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda-shi, Chiba-ken, Japan
| | - Sei-Ichi Tanuma
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda-shi, Chiba-ken, Japan
- Genomic Medical Science, Research Institute of Science and Technology, Tokyo University of Science, Noda-shi, Chiba-ken, Japan
| | - Fumiaki Uchiumi
- Department of Gene Regulation, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda-shi, Chiba-ken, Japan
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The Temporal Regulation of S Phase Proteins During G 1. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1042:335-369. [PMID: 29357066 DOI: 10.1007/978-981-10-6955-0_16] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Successful DNA replication requires intimate coordination with cell-cycle progression. Prior to DNA replication initiation in S phase, a series of essential preparatory events in G1 phase ensures timely, complete, and precise genome duplication. Among the essential molecular processes are regulated transcriptional upregulation of genes that encode replication proteins, appropriate post-transcriptional control of replication factor abundance and activity, and assembly of DNA-loaded protein complexes to license replication origins. In this chapter we describe these critical G1 events necessary for DNA replication and their regulation in the context of both cell-cycle entry and cell-cycle progression.
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12
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A Abdullah A, Abdullah R, A Nazariah Z, N Balakrishnan K, Firdaus J Abdullah F, A Bala J, Mohd-Lila MA. Cyclophilin A as a target in the treatment of cytomegalovirus infections. Antivir Chem Chemother 2018; 26:2040206618811413. [PMID: 30449131 PMCID: PMC6243413 DOI: 10.1177/2040206618811413] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 10/12/2018] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Viruses are obligate parasites that depend on the cellular machinery of the host to regenerate and manufacture their proteins. Most antiviral drugs on the market today target viral proteins. However, the more recent strategies involve targeting the host cell proteins or pathways that mediate viral replication. This new approach would be effective for most viruses while minimizing drug resistance and toxicity. METHODS Cytomegalovirus replication, latency, and immune response are mediated by the intermediate early protein 2, the main protein that determines the effectiveness of drugs in cytomegalovirus inhibition. This review explains how intermediate early protein 2 can modify the action of cyclosporin A, an immunosuppressive, and antiviral drug. It also links all the pathways mediated by cyclosporin A, cytomegalovirus replication, and its encoded proteins. RESULTS Intermediate early protein 2 can influence the cellular cyclophilin A pathway, affecting cyclosporin A as a mediator of viral replication or anti-cytomegalovirus drug. CONCLUSION Cyclosporin A has a dual function in cytomegalovirus pathogenesis. It has the immunosuppressive effect that establishes virus replication through the inhibition of T-cell function. It also has an anti-cytomegalovirus effect mediated by intermediate early protein 2. Both of these functions involve cyclophilin A pathway.
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Affiliation(s)
- Ashwaq A Abdullah
- 1 Institute of Bioscience, University Putra Malaysia, Serdang, Selangor D.E, Malaysia
- 2 Department of Microbiology, Faculty of Applied Science, Taiz University, Taiz, Yemen
| | - Rasedee Abdullah
- 1 Institute of Bioscience, University Putra Malaysia, Serdang, Selangor D.E, Malaysia
- 3 Department of Veterinary Laboratory Diagnosis, Universiti Putra Malaysia, Serdang, Selangor D.E, Malaysia
| | - Zeenathul A Nazariah
- 1 Institute of Bioscience, University Putra Malaysia, Serdang, Selangor D.E, Malaysia
- 4 Department of Pathology and Microbiology, Universiti Putra Malaysia, Serdang, Selangor D.E, Malaysia
| | - Krishnan N Balakrishnan
- 4 Department of Pathology and Microbiology, Universiti Putra Malaysia, Serdang, Selangor D.E, Malaysia
| | - Faez Firdaus J Abdullah
- 5 Department of Veterinary Clinical Studies, Faculty of Veterinary Medicine, Universiti Putra Malaysia, Serdang, Selangor D.E, Malaysia
| | - Jamilu A Bala
- 4 Department of Pathology and Microbiology, Universiti Putra Malaysia, Serdang, Selangor D.E, Malaysia
- 6 Department of Medical Laboratory Science, Faculty of Allied Health Sciences, Bayero University Kano, Kano, Nigeria
| | - Mohd-Azmi Mohd-Lila
- 1 Institute of Bioscience, University Putra Malaysia, Serdang, Selangor D.E, Malaysia
- 4 Department of Pathology and Microbiology, Universiti Putra Malaysia, Serdang, Selangor D.E, Malaysia
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13
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Fischer M, Müller GA. Cell cycle transcription control: DREAM/MuvB and RB-E2F complexes. Crit Rev Biochem Mol Biol 2017; 52:638-662. [PMID: 28799433 DOI: 10.1080/10409238.2017.1360836] [Citation(s) in RCA: 150] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The precise timing of cell cycle gene expression is critical for the control of cell proliferation; de-regulation of this timing promotes the formation of cancer and leads to defects during differentiation and development. Entry into and progression through S phase requires expression of genes coding for proteins that function in DNA replication. Expression of a distinct set of genes is essential to pass through mitosis and cytokinesis. Expression of these groups of cell cycle-dependent genes is regulated by the RB pocket protein family, the E2F transcription factor family, and MuvB complexes together with B-MYB and FOXM1. Distinct combinations of these transcription factors promote the transcription of the two major groups of cell cycle genes that are maximally expressed either in S phase (G1/S) or in mitosis (G2/M). In this review, we discuss recent work that has started to uncover the molecular mechanisms controlling the precisely timed expression of these genes at specific cell cycle phases, as well as the repression of the genes when a cell exits the cell cycle.
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Affiliation(s)
- Martin Fischer
- a Molecular Oncology, Medical School, University of Leipzig , Leipzig , Germany.,b Department of Medical Oncology , Dana-Farber Cancer Institute , Boston , MA , USA.,c Department of Medicine, Brigham and Women's Hospital , Harvard Medical School , Boston , MA , USA
| | - Gerd A Müller
- a Molecular Oncology, Medical School, University of Leipzig , Leipzig , Germany
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14
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Barr JY, Goodfellow RX, Colgan DF, Colgan JD. Early B Cell Progenitors Deficient for GON4L Fail To Differentiate Due to a Block in Mitotic Cell Division. THE JOURNAL OF IMMUNOLOGY 2017; 198:3978-3988. [PMID: 28381640 DOI: 10.4049/jimmunol.1602054] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 03/14/2017] [Indexed: 11/19/2022]
Abstract
B cell development in Justy mutant mice is blocked due to a precursor mRNA splicing defect that depletes the protein GON4-like (GON4L) in B cell progenitors. Genetic and biochemical studies have suggested that GON4L is a transcriptional regulator that coordinates cell division with differentiation, but its role in B cell development is unknown. To understand the function of GON4L, we characterized B cell differentiation, cell cycle control, and mitotic gene expression in GON4L-deficient B cell progenitors from Justy mice. We found that these cells established key aspects of the transcription factor network that guides B cell development and proliferation and rearranged the IgH gene locus. However, despite intact IL-7 signaling, GON4L-deficient pro-B cell stage precursors failed to undergo a characteristic IL-7-dependent proliferative burst. These cells also failed to upregulate genes required for mitotic division, including those encoding the G1/S cyclin D3 and E2F transcription factors and their targets. Additionally, GON4L-deficient B cell progenitors displayed defects in DNA synthesis and passage through the G1/S transition, contained fragmented DNA, and underwent apoptosis. These phenotypes were not suppressed by transgenic expression of prosurvival factors. However, transgenic expression of cyclin D3 or other regulators of the G1/S transition restored pro-B cell development from Justy progenitor cells, suggesting that GON4L acts at the beginning of the cell cycle. Together, our findings indicate that GON4L is essential for cell cycle progression and division during the early stages of B cell development.
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Affiliation(s)
- Jennifer Y Barr
- Department of Anatomy and Cell Biology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242
| | - Renee X Goodfellow
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA 52242; and
| | - Diana F Colgan
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA 52242; and
| | - John D Colgan
- Department of Anatomy and Cell Biology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242; .,Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA 52242; and.,Interdisciplinary Graduate Program in Immunology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242
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15
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Cell Death in Chondrocytes, Osteoblasts, and Osteocytes. Int J Mol Sci 2016; 17:ijms17122045. [PMID: 27929439 PMCID: PMC5187845 DOI: 10.3390/ijms17122045] [Citation(s) in RCA: 113] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 11/13/2016] [Accepted: 11/23/2016] [Indexed: 12/04/2022] Open
Abstract
Cell death in skeletal component cells, including chondrocytes, osteoblasts, and osteocytes, plays roles in skeletal development, maintenance, and repair as well as in the pathogenesis of osteoarthritis and osteoporosis. Chondrocyte proliferation, differentiation, and apoptosis are important steps for endochondral ossification. Although the inactivation of P53 and RB is involved in the pathogenesis of osteosarcomas, the deletion of p53 and inactivation of Rb are insufficient to enhance chondrocyte proliferation, indicating the presence of multiple inhibitory mechanisms against sarcomagenesis in chondrocytes. The inflammatory processes induced by mechanical injury and chondrocyte death through the release of danger-associated molecular patterns (DAMPs) are involved in the pathogenesis of posttraumatic osteoarthritis. The overexpression of BCLXL increases bone volume with a normal structure and maintains bone during aging by inhibiting osteoblast apoptosis. p53 inhibits osteoblast proliferation and enhances osteoblast apoptosis, thereby reducing bone formation, but also exerts positive effects on osteoblast differentiation through the Akt–FoxOs pathway. Apoptotic osteocytes release ATP, which induces the receptor activator of nuclear factor κ-B ligand (Rankl) expression and osteoclastogenesis, from pannexin 1 channels. Osteocyte death ultimately results in necrosis; DAMPs are released to the bone surface and promote the production of proinflammatory cytokines, which induce Rankl expression, and osteoclastogenesis is further enhanced.
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16
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De Sousa M, Porras DP, Perry CGR, Seale P, Scimè A. p107 is a crucial regulator for determining the adipocyte lineage fate choices of stem cells. Stem Cells 2014; 32:1323-36. [PMID: 24449206 DOI: 10.1002/stem.1637] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 11/20/2013] [Indexed: 12/11/2022]
Abstract
Thermogenic (beige and brown) adipocytes protect animals against obesity and metabolic disease. However, little is known about the mechanisms that commit stem cells toward different adipocyte lineages. We show here that p107 is a master regulator of adipocyte lineage fates, its suppression required for commitment of stem cells to the brown-type fate. p107 is strictly expressed in the stem cell compartment of white adipose tissue depots and completely absent in brown adipose tissue. Remarkably, p107-deficient stem cells uniformly give rise to brown-type adipocytes in vitro and in vivo. Furthermore, brown fat programming of mesenchymal stem cells by PRDM-BF1-RIZ1 homologous domain containing 16 (Prdm16) was associated with a dramatic reduction of p107 levels. Indeed, Prdm16 directly suppressed p107 transcription via promoter binding. Notably, the sustained expression of p107 blocked the ability of Prdm16 to induce brown fat genes. These findings demonstrate that p107 expression in stem cells commits cells to the white versus brown adipose lineage.
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Affiliation(s)
- Martina De Sousa
- Stem Cell Research Group, Faculty of Health, York University, Toronto, Ontario, Canada
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17
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Kareta MS, Gorges LL, Hafeez S, Benayoun BA, Marro S, Zmoos AF, Cecchini MJ, Spacek D, Batista LFZ, O'Brien M, Ng YH, Ang CE, Vaka D, Artandi SE, Dick FA, Brunet A, Sage J, Wernig M. Inhibition of pluripotency networks by the Rb tumor suppressor restricts reprogramming and tumorigenesis. Cell Stem Cell 2014; 16:39-50. [PMID: 25467916 DOI: 10.1016/j.stem.2014.10.019] [Citation(s) in RCA: 143] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Revised: 08/18/2014] [Accepted: 10/24/2014] [Indexed: 12/15/2022]
Abstract
Mutations in the retinoblastoma tumor suppressor gene Rb are involved in many forms of human cancer. In this study, we investigated the early consequences of inactivating Rb in the context of cellular reprogramming. We found that Rb inactivation promotes the reprogramming of differentiated cells to a pluripotent state. Unexpectedly, this effect is cell cycle independent, and instead reflects direct binding of Rb to pluripotency genes, including Sox2 and Oct4, which leads to a repressed chromatin state. More broadly, this regulation of pluripotency networks and Sox2 in particular is critical for the initiation of tumors upon loss of Rb in mice. These studies therefore identify Rb as a global transcriptional repressor of pluripotency networks, providing a molecular basis for previous reports about its involvement in cell fate pliability, and implicate misregulation of pluripotency factors such as Sox2 in tumorigenesis related to loss of Rb function.
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Affiliation(s)
- Michael S Kareta
- Department of Pediatrics, Stanford University, Stanford, CA 94305, USA; Department of Genetics, Stanford University, Stanford, CA 94305, USA; Department of Pathology, Stanford University, Stanford, CA 94305, USA; Stanford Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, CA 94305, USA
| | - Laura L Gorges
- Department of Pediatrics, Stanford University, Stanford, CA 94305, USA; Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Sana Hafeez
- Department of Pathology, Stanford University, Stanford, CA 94305, USA; Stanford Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, CA 94305, USA
| | - Bérénice A Benayoun
- Department of Genetics, Stanford University, Stanford, CA 94305, USA; Paul F. Glenn Laboratories for the Biology of Aging, Stanford University, Stanford, CA 94305, USA
| | - Samuele Marro
- Department of Pathology, Stanford University, Stanford, CA 94305, USA; Stanford Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, CA 94305, USA
| | - Anne-Flore Zmoos
- Department of Pediatrics, Stanford University, Stanford, CA 94305, USA; Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Matthew J Cecchini
- London Regional Cancer Program, Children's Research Institute, Western University, London, ON N6A 4L6, Canada
| | - Damek Spacek
- Department of Pediatrics, Stanford University, Stanford, CA 94305, USA; Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Luis F Z Batista
- Department of Medicine, Stanford University, Stanford, CA 94305, USA; Department of Biochemistry, Stanford University, Stanford, CA 94305, USA; Stanford Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, CA 94305, USA
| | - Megan O'Brien
- Department of Pediatrics, Stanford University, Stanford, CA 94305, USA; Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Yi-Han Ng
- Department of Pathology, Stanford University, Stanford, CA 94305, USA; Stanford Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, CA 94305, USA
| | - Cheen Euong Ang
- Department of Pathology, Stanford University, Stanford, CA 94305, USA; Stanford Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, CA 94305, USA
| | - Dedeepya Vaka
- Department of Pediatrics, Stanford University, Stanford, CA 94305, USA; Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Steven E Artandi
- Department of Medicine, Stanford University, Stanford, CA 94305, USA; Department of Biochemistry, Stanford University, Stanford, CA 94305, USA; Stanford Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, CA 94305, USA
| | - Frederick A Dick
- London Regional Cancer Program, Children's Research Institute, Western University, London, ON N6A 4L6, Canada
| | - Anne Brunet
- Department of Genetics, Stanford University, Stanford, CA 94305, USA; Paul F. Glenn Laboratories for the Biology of Aging, Stanford University, Stanford, CA 94305, USA
| | - Julien Sage
- Department of Pediatrics, Stanford University, Stanford, CA 94305, USA; Department of Genetics, Stanford University, Stanford, CA 94305, USA.
| | - Marius Wernig
- Department of Pathology, Stanford University, Stanford, CA 94305, USA; Stanford Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, CA 94305, USA.
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Host cell factor-1 recruitment to E2F-bound and cell-cycle-control genes is mediated by THAP11 and ZNF143. Cell Rep 2014; 9:967-82. [PMID: 25437553 DOI: 10.1016/j.celrep.2014.09.051] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 09/03/2014] [Accepted: 09/28/2014] [Indexed: 11/21/2022] Open
Abstract
Host cell factor-1 (HCF-1) is a metazoan transcriptional coregulator essential for cell-cycle progression and cell proliferation. Current models suggest a mechanism whereby HCF-1 functions as a direct coregulator of E2F proteins, facilitating the expression of genes necessary for cell proliferation. In this report, we show that HCF-1 recruitment to numerous E2F-bound promoters is mediated by the concerted action of zinc finger transcription factors THAP11 and ZNF143, rather than E2F proteins directly. THAP11, ZNF143, and HCF-1 form a mutually dependent complex on chromatin, which is independent of E2F occupancy. Disruption of the THAP11/ZNF143/HCF-1 complex results in altered expression of cell-cycle control genes and leads to reduced cell proliferation, cell-cycle progression, and cell viability. These data establish a model in which a THAP11/ZNF143/HCF-1 complex is a critical component of the transcriptional regulatory network governing cell proliferation.
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Retinoblastoma protein (RB) interacts with E2F3 to control terminal differentiation of Sertoli cells. Cell Death Dis 2014; 5:e1274. [PMID: 24901045 PMCID: PMC4611710 DOI: 10.1038/cddis.2014.232] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Revised: 04/08/2014] [Accepted: 04/09/2014] [Indexed: 11/09/2022]
Abstract
The retinoblastoma protein (RB) is essential for normal cell cycle control. RB function depends, at least in part, on interactions with the E2F family of DNA-binding transcription factors (E2Fs). To study the role of RB in the adult testis, a Sertoli cell (SC)-specific Rb knockout mouse line (SC-RbKO) was generated using the Cre/loxP recombination system. SC-RbKO mice exhibited an age-dependent testicular atrophy, impaired fertility, severe SC dysfunction, and spermatogenic defects. Removal of Rb in SC induced aberrant SC cycling, dedifferentiation, and apoptosis. Here we show that E2F3 is the only E2F expressed in mouse SCs and that RB interacts with E2F3 during mouse testicular development. In the absence of RB, the other retinoblastoma family members p107 and p130 began interacting with E2F3 in the adult testes. In vivo silencing of E2F3 partially restored the SC maturation and survival as well as spermatogenesis in the SC-RbKO mice. These results point to RB as a key regulator of SC function in adult mice and that the RB/E2F3 pathway directs SC maturation, cell cycle quiescence, and RB protects SC from apoptosis.
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21
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The RB family is required for the self-renewal and survival of human embryonic stem cells. Nat Commun 2013; 3:1244. [PMID: 23212373 DOI: 10.1038/ncomms2254] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Accepted: 11/05/2012] [Indexed: 12/27/2022] Open
Abstract
The mechanisms ensuring the long-term self-renewal of human embryonic stem cells are still only partly understood, limiting their use in cellular therapies. Here we found that increased activity of the RB cell cycle inhibitor in human embryonic stem cells induces cell cycle arrest, differentiation and cell death. Conversely, inactivation of the entire RB family (RB, p107 and p130) in human embryonic stem cells triggers G2/M arrest and cell death through functional activation of the p53 pathway and the cell cycle inhibitor p21. Differences in E2F target gene activation upon loss of RB family function between human embryonic stem cells, mouse embryonic stem cells and human fibroblasts underscore key differences in the cell cycle regulatory networks of human embryonic stem cells. Finally, loss of RB family function promotes genomic instability in both human and mouse embryonic stem cells, uncoupling cell cycle defects from chromosomal instability. These experiments indicate that a homeostatic level of RB activity is essential for the self-renewal and the survival of human embryonic stem cells.
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Overexpression of Cdk6 and Ccnd1 in chondrocytes inhibited chondrocyte maturation and caused p53-dependent apoptosis without enhancing proliferation. Oncogene 2013; 33:1862-71. [PMID: 23624920 DOI: 10.1038/onc.2013.130] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Revised: 02/21/2013] [Accepted: 03/04/2013] [Indexed: 12/21/2022]
Abstract
Cell proliferation and differentiation are closely coupled. However, we previously showed that overexpression of cyclin-dependent kinase (Cdk6) blocks chondrocyte differentiation without affecting cell-cycle progression in vitro. To investigate whether Cdk6 inhibits chondrocyte differentiation in vivo, we generated chondrocyte-specific Cdk6 transgenic mice using Col2a1 promoter. Unexpectedly, differentiation and cell-cycle progression of chondrocytes in the Cdk6 transgenic mice were similar to those in wild-type mice. Then, we generated chondrocyte-specific Ccnd1 transgenic mice and Cdk6/Ccnd1 double transgenic mice to investigate the possibility that Cdk6 inhibits chondrocyte differentiation through E2f activation. Bromodeoxyuridine (BrdU)-positive chondrocytes and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive chondrocytes were increased in number, and chondrocyte maturation was inhibited only in Cdk6/Ccnd1 transgenic mice (K6(H)/D1(H) mice), which showed dwarfism. Retinoblastoma protein (pRb) was highly phosphorylated but p107 was upregulated, and the expression of E2f target genes was dysregulated as shown by upregulation of Cdc6 but downregulation of cyclin E, dihydrofolate reductase (dhfr), Cdc25a and B-Myb in chondrocytes of K6(H)/D1(H) mice. Similarly, overexpression of Cdk6/Ccnd1 in a chondrogenic cell line ATDC5 highly phosphorylated pRb, upregulated p107, induced apoptosis, upregulated Cdc6 and downregulated cyclin E, dhfr and B-Myb and p107 small interfering RNA reversed the expression of downregulated genes. Further, introduction of kinase-negative Cdk6 and cyclin D1 abolished all effects by Cdk6/cyclin D1 in ATDC5 cells, indicating the requirement of the kinase activity on these effects. p53 deletion partially restored the size of the skeleton and almost completely rescued chondrocyte apoptosis, but failed to enhance chondrocyte proliferation in K6(H)/D1(H) mice. These findings indicated that Cdk6/Ccnd1 overexpression inhibited chondrocyte maturation and enhanced G1/S cell-cycle transition by phosphorylating pRb, but the chondrocytes failed to accomplish the cell cycle, and underwent p53-dependent apoptosis probably due to the dysregulation of E2f target genes. Our findings also indicated that p53 deletion in addition to the inactivation of Rb was not sufficient to accelerate chondrocyte proliferation, suggesting the resistance of chondrocytes to sarcomagenesis.
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Chang CN, Feng MJ, Chen YL, Yuan RH, Jeng YM. p15(PAF) is an Rb/E2F-regulated S-phase protein essential for DNA synthesis and cell cycle progression. PLoS One 2013; 8:e61196. [PMID: 23593430 PMCID: PMC3617190 DOI: 10.1371/journal.pone.0061196] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2012] [Accepted: 03/07/2013] [Indexed: 11/18/2022] Open
Abstract
The p15(PAF)/KIAA0101 protein is a proliferating cell nuclear antigen (PCNA)-associated protein overexpressed in multiple types of cancer. Attenuation of p15(PAF) expression leads to modifications in the DNA repair process, rendering cells more sensitive to ultraviolet-induced cell death. In this study, we identified that p15(PAF) expression peaks during the S phase of the cell cycle. We observed that p15(PAF) knockdown markedly inhibited cell proliferation, S-phase progression, and DNA synthesis. Depletion of p15(PAF) resulted in p21 upregulation, especially chromatin-bound p21. We further identified that the p15(PAF) promoter contains 3 E2F-binding motifs. Loss of Rb-mediated transcriptional repression resulted in upregulated p15(PAF) expression. Binding of E2F4 and E2F6 to the p15(PAF) promoter caused transcriptional repression. Overall, these results indicate that p15(PAF) is tightly regulated by the Rb/E2F complex. Loss of Rb/E2F-mediated repression during the G1/S transition phase leads to p15(PAF) upregulation, which facilitates DNA synthesis and S-phase progression.
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Affiliation(s)
- Chih-Ning Chang
- Graduate Institute of Pathology, National Taiwan University, Taipei, Taiwan
| | - Mow-Jung Feng
- Graduate Institute of Pathology, National Taiwan University, Taipei, Taiwan
| | - Yu-Ling Chen
- Graduate Institute of Pathology, National Taiwan University, Taipei, Taiwan
| | - Ray-Hwang Yuan
- Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan
| | - Yung-Ming Jeng
- Graduate Institute of Pathology, National Taiwan University, Taipei, Taiwan
- Department of Pathology, National Taiwan University Hospital, Taipei, Taiwan
- * E-mail:
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Evidence for autoregulation and cell signaling pathway regulation from genome-wide binding of the Drosophila retinoblastoma protein. G3-GENES GENOMES GENETICS 2012; 2:1459-72. [PMID: 23173097 PMCID: PMC3484676 DOI: 10.1534/g3.112.004424] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Accepted: 09/20/2012] [Indexed: 12/24/2022]
Abstract
The retinoblastoma (RB) tumor suppressor protein is a transcriptional cofactor with essential roles in cell cycle and development. Physical and functional targets of RB and its paralogs p107/p130 have been studied largely in cultured cells, but the full biological context of this family of proteins' activities will likely be revealed only in whole organismal studies. To identify direct targets of the major Drosophila RB counterpart in a developmental context, we carried out ChIP-Seq analysis of Rbf1 in the embryo. The association of the protein with promoters is developmentally controlled; early promoter access is globally inhibited, whereas later in development Rbf1 is found to associate with promoter-proximal regions of approximately 2000 genes. In addition to conserved cell-cycle-related genes, a wholly unexpected finding was that Rbf1 targets many components of the insulin, Hippo, JAK/STAT, Notch, and other conserved signaling pathways. Rbf1 may thus directly affect output of these essential growth-control and differentiation pathways by regulation of expression of receptors, kinases and downstream effectors. Rbf1 was also found to target multiple levels of its own regulatory hierarchy. Bioinformatic analysis indicates that different classes of genes exhibit distinct constellations of motifs associated with the Rbf1-bound regions, suggesting that the context of Rbf1 recruitment may vary within the Rbf1 regulon. Many of these targeted genes are bound by Rbf1 homologs in human cells, indicating that a conserved role of RB proteins may be to adjust the set point of interlinked signaling networks essential for growth and development.
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Abstract
Retinoblastoma is a rare pediatric cancer that has served as a paradigm to investigate the mechanisms of tumorigenesis. In this issue of Genes & Development, Conkrite and colleagues (pp. 1734-1745) found high levels of the miR-17~92 and miR-106b-25 microRNAs in primary retinoblastomas and show that overexpression of miR-17~92 accelerates retinoblastoma development in mice by promoting proliferation, in part by reducing expression of the cell cycle inhibitor p21. These experiments identify the RB/miR-17~92/p21 axis as a critical regulator of retinoblastoma tumorigenesis and potentially many other cancers.
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Affiliation(s)
- Julien Sage
- Department of Pediatrics, Stanford University, Stanford, California 94305, USA
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Ciavarra G, Ho AT, Cobrinik D, Zacksenhaus E. Critical role of the Rb family in myoblast survival and fusion. PLoS One 2011; 6:e17682. [PMID: 21423694 PMCID: PMC3053373 DOI: 10.1371/journal.pone.0017682] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Accepted: 02/08/2011] [Indexed: 12/23/2022] Open
Abstract
The tumor suppressor Rb is thought to control cell proliferation, survival and differentiation. We recently showed that differentiating Rb-deficient mouse myoblasts can fuse to form short myotubes that quickly collapse through a mechanism involving autophagy, and that autophagy inhibitors or hypoxia could rescue the defect leading to long, twitching myotubes. Here we determined the contribution of pRb relatives, p107 and p130, to this process. We show that chronic or acute inactivation of Rb plus p107 or p130 increased myoblast cell death and reduced myotube formation relative to Rb loss alone. Treatment with autophagy antagonists or hypoxia extended survival of double-knockout myotubes, which appeared indistinguishable from control fibers. In contrast, triple mutations in Rb, p107 and p130, led to substantial increase in myoblast death and to elongated bi-nuclear myocytes, which seem to derive from nuclear duplication, as opposed to cell fusion. Under hypoxia, some rare, abnormally thin triple knockout myotubes survived and twitched. Thus, mutation of p107 or p130 reduces survival of Rb-deficient myoblasts during differentiation but does not preclude myoblast fusion or necessitate myotube degeneration, whereas combined inactivation of the entire Rb family produces a distinct phenotype, with drastically impaired myoblast fusion and survival.
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Affiliation(s)
- Giovanni Ciavarra
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Andrew T. Ho
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - David Cobrinik
- Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America
| | - Eldad Zacksenhaus
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
- Division of Cell and Molecular Biology, Toronto General Research Institute - University Health Network, Toronto, Ontario, Canada
- * E-mail:
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27
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Judah D, Chang WY, Dagnino L. EBP1 is a novel E2F target gene regulated by transforming growth factor-β. PLoS One 2010; 5:e13941. [PMID: 21085677 PMCID: PMC2978110 DOI: 10.1371/journal.pone.0013941] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Accepted: 10/18/2010] [Indexed: 12/20/2022] Open
Abstract
Regulation of gene expression requires transcription factor binding to specific DNA elements, and a large body of work has focused on the identification of such sequences. However, it is becoming increasingly clear that eukaryotic transcription factors can exhibit widespread, nonfunctional binding to genomic DNA sites. Conversely, some of these proteins, such as E2F, can also modulate gene expression by binding to non-consensus elements. E2F comprises a family of transcription factors that play key roles in a wide variety of cellular functions, including survival, differentiation, activation during tissue regeneration, metabolism, and proliferation. E2F factors bind to the Erb3-binding protein 1 (EBP1) promoter in live cells. We now show that E2F binding to the EBP1 promoter occurs through two tandem DNA elements that do not conform to typical consensus E2F motifs. Exogenously expressed E2F1 activates EBP1 reporters lacking one, but not both sites, suggesting a degree of redundancy under certain conditions. E2F1 increases the levels of endogenous EBP1 mRNA in breast carcinoma and other transformed cell lines. In contrast, in non-transformed primary epidermal keratinocytes, E2F, together with the retinoblastoma family of proteins, appears to be involved in decreasing EBP1 mRNA abundance in response to growth inhibition by transforming growth factor-β1. Thus, E2F is likely a central coordinator of multiple responses that culminate in regulation of EBP1 gene expression, and which may vary depending on cell type and context.
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Affiliation(s)
- David Judah
- Department of Physiology and Pharmacology, Children Health Research Institute and Lawson Health Research Institute, University of Western Ontario, London, Canada
| | - Wing Y. Chang
- Department of Physiology and Pharmacology, Children Health Research Institute and Lawson Health Research Institute, University of Western Ontario, London, Canada
| | - Lina Dagnino
- Department of Physiology and Pharmacology, Children Health Research Institute and Lawson Health Research Institute, University of Western Ontario, London, Canada
- Department of Paediatrics, Children Health Research Institute and Lawson Health Research Institute, University of Western Ontario, London, Canada
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