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Lv Z, Xiao L, Tang Y, Chen Y, Chen D. Rb deficiency induces p21cip1 expression and delays retinal degeneration in rd1 mice. Exp Eye Res 2021; 210:108701. [PMID: 34252413 DOI: 10.1016/j.exer.2021.108701] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 07/04/2021] [Accepted: 07/07/2021] [Indexed: 02/08/2023]
Abstract
Retinitis pigmentosa (RP) is a major cause of inherited blindness, and there is presently no cure for RP. Rd1 mouse is the most commonly used RP animal model. Re-expression of cell cycle proteins in post-mitotic neurons is considered an important mechanism of neurodegenerative diseases, including RP. The retinoblastoma tumor suppressor (Rb) is a major regulator of cell cycle progression, yet its role in rd1 mouse retina and related signaling pathways have never been analyzed. By crossing α-Cre, Rbf/f mice with rd1 mice, p21cip1-/- mice, Cdk1f/f mice and Cdk2f/f mice, we established multiple rd1 mouse models with deletions of Rb gene, Cdkn1a (p21cip1) gene, Cdk1 and Cdk2 gene in the retina. Cdk inhibitor CR8 was injected into the vitreous of rd1 mouse to investigate its effects on photoreceptor survival. Rb gene knockout (KO) induces cell death in excitatory retinal neurons (rods, rod bipolar and ganglions) and ectopic proliferation of retinal cells; but it paradoxically delays the rod death of rd1 mice, which is primarily mediated by the Cdk inhibitor Cdkn1a (p21cip1). Interestingly, p21cip1 protects the ectopic dividing rd1 rod cells by inhibiting Cdk1 and Cdk2. However, inhibiting Cdk1 and Cdk2 in rd1 mice with non-dividing rods only has limited and transient protective effects. Our data suggest that there is no ectopic division of rd1 rod cells, and RbKO induces ectopic division but delays the death of rd1 rod cells. This reveals the important protective role of Rb-p21cip1-Cdk axis in rd1 rod cells. P21cip1 is a potential target for future therapy of RP.
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Affiliation(s)
- Zhongping Lv
- The Research Laboratory of Ophthalmology and Vision Sciences, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, 610041, China; The Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Lirong Xiao
- The Research Laboratory of Ophthalmology and Vision Sciences, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Yunjing Tang
- The Research Laboratory of Ophthalmology and Vision Sciences, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, 610041, China; The Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Yongjiang Chen
- The School of Optometry and Vision Science, University of Waterloo, 200 University Ave. W., Waterloo, ON, N2L 3G1, Canada
| | - Danian Chen
- The Research Laboratory of Ophthalmology and Vision Sciences, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, 610041, China; The Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, 610041, China.
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2
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Balakrishnan I, Danis E, Pierce A, Madhavan K, Wang D, Dahl N, Sanford B, Birks DK, Davidson N, Metselaar DS, Meel MH, Lemma R, Donson A, Vijmasi T, Katagi H, Sola I, Fosmire S, Alimova I, Steiner J, Gilani A, Hulleman E, Serkova NJ, Hashizume R, Hawkins C, Carcaboso AM, Gupta N, Monje M, Jabado N, Jones K, Foreman N, Green A, Vibhakar R, Venkataraman S. Senescence Induced by BMI1 Inhibition Is a Therapeutic Vulnerability in H3K27M-Mutant DIPG. Cell Rep 2020; 33:108286. [PMID: 33086074 PMCID: PMC7574900 DOI: 10.1016/j.celrep.2020.108286] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 07/05/2020] [Accepted: 09/25/2020] [Indexed: 01/19/2023] Open
Abstract
Diffuse intrinsic pontine glioma (DIPG) is an incurable brain tumor of childhood characterized by histone mutations at lysine 27, which results in epigenomic dysregulation. There has been a failure to develop effective treatment for this tumor. Using a combined RNAi and chemical screen targeting epigenomic regulators, we identify the polycomb repressive complex 1 (PRC1) component BMI1 as a critical factor for DIPG tumor maintenance in vivo. BMI1 chromatin occupancy is enriched at genes associated with differentiation and tumor suppressors in DIPG cells. Inhibition of BMI1 decreases cell self-renewal and attenuates tumor growth due to induction of senescence. Prolonged BMI1 inhibition induces a senescence-associated secretory phenotype, which promotes tumor recurrence. Clearance of senescent cells using BH3 protein mimetics co-operates with BMI1 inhibition to enhance tumor cell killing in vivo.
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Affiliation(s)
- Ilango Balakrishnan
- Department of Pediatrics and Section of Pediatric Hematology/Oncology/BMT, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA; The Morgan Adams Foundation Pediatric Brain Tumor Research Program, Children's Hospital Colorado, Aurora, CO, USA
| | - Etienne Danis
- Department of Pediatrics and Section of Pediatric Hematology/Oncology/BMT, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA; The Morgan Adams Foundation Pediatric Brain Tumor Research Program, Children's Hospital Colorado, Aurora, CO, USA
| | - Angela Pierce
- Department of Pediatrics and Section of Pediatric Hematology/Oncology/BMT, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
| | - Krishna Madhavan
- Department of Pediatrics and Section of Pediatric Hematology/Oncology/BMT, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA; The Morgan Adams Foundation Pediatric Brain Tumor Research Program, Children's Hospital Colorado, Aurora, CO, USA
| | - Dong Wang
- Department of Pediatrics and Section of Pediatric Hematology/Oncology/BMT, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
| | - Nathan Dahl
- Department of Pediatrics and Section of Pediatric Hematology/Oncology/BMT, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA; The Morgan Adams Foundation Pediatric Brain Tumor Research Program, Children's Hospital Colorado, Aurora, CO, USA
| | - Bridget Sanford
- Department of Pediatrics and Section of Pediatric Hematology/Oncology/BMT, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
| | - Diane K Birks
- Department of Pediatrics and Section of Pediatric Hematology/Oncology/BMT, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
| | - Nate Davidson
- Department of Pediatrics and Section of Pediatric Hematology/Oncology/BMT, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
| | - Dennis S Metselaar
- Princess Máxima Center for Pediatric Oncology, Utrecht and Departments of Pediatric Oncology/Hematology, Cancer Center Amsterdam, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - Michaël Hananja Meel
- Princess Máxima Center for Pediatric Oncology, Utrecht and Departments of Pediatric Oncology/Hematology, Cancer Center Amsterdam, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - Rakeb Lemma
- Department of Pediatrics and Section of Pediatric Hematology/Oncology/BMT, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
| | - Andrew Donson
- Department of Pediatrics and Section of Pediatric Hematology/Oncology/BMT, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA; The Morgan Adams Foundation Pediatric Brain Tumor Research Program, Children's Hospital Colorado, Aurora, CO, USA
| | - Trinka Vijmasi
- Department of Pediatrics and Section of Pediatric Hematology/Oncology/BMT, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA; The Morgan Adams Foundation Pediatric Brain Tumor Research Program, Children's Hospital Colorado, Aurora, CO, USA
| | - Hiroaki Katagi
- Department of Neurological Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Ismail Sola
- Department of Pediatrics and Section of Pediatric Hematology/Oncology/BMT, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
| | - Susan Fosmire
- Department of Pediatrics and Section of Pediatric Hematology/Oncology/BMT, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
| | - Irina Alimova
- Department of Pediatrics and Section of Pediatric Hematology/Oncology/BMT, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
| | - Jenna Steiner
- Departments of Radiology, Radiation Oncology, and Anesthesiology, Colorado Animal Imaging Shared Resource (AISR), University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Ahmed Gilani
- Department of Pathology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Esther Hulleman
- Princess Máxima Center for Pediatric Oncology, Utrecht and Departments of Pediatric Oncology/Hematology, Cancer Center Amsterdam, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - Natalie J Serkova
- Departments of Radiology, Radiation Oncology, and Anesthesiology, Colorado Animal Imaging Shared Resource (AISR), University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Rintaro Hashizume
- Department of Neurological Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Cynthia Hawkins
- Arthur and Sonia Labatt Brain Tumor Research Centre, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Angel M Carcaboso
- Pediatric Hematology and Oncology, Hospital Sant Joan de Deu, Institut de Recerca Sant Joan de Deu, Barcelona 08950, Spain
| | - Nalin Gupta
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, USA
| | - Michelle Monje
- Departments of Neurology, Neurosurgery, Pediatrics, and Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Nada Jabado
- Department of Human Genetics, McGill University, Montreal, QC H3A 1B1, Canada; Department of Pediatrics, McGill University, and The Research Institute of the McGill University Health Center, Montreal, QC H4A 3J1, Canada
| | - Kenneth Jones
- Department of Pediatrics and Section of Pediatric Hematology/Oncology/BMT, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
| | - Nicholas Foreman
- Department of Pediatrics and Section of Pediatric Hematology/Oncology/BMT, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA; The Morgan Adams Foundation Pediatric Brain Tumor Research Program, Children's Hospital Colorado, Aurora, CO, USA
| | - Adam Green
- Department of Pediatrics and Section of Pediatric Hematology/Oncology/BMT, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA; The Morgan Adams Foundation Pediatric Brain Tumor Research Program, Children's Hospital Colorado, Aurora, CO, USA
| | - Rajeev Vibhakar
- Department of Pediatrics and Section of Pediatric Hematology/Oncology/BMT, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA; The Morgan Adams Foundation Pediatric Brain Tumor Research Program, Children's Hospital Colorado, Aurora, CO, USA.
| | - Sujatha Venkataraman
- Department of Pediatrics and Section of Pediatric Hematology/Oncology/BMT, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA; The Morgan Adams Foundation Pediatric Brain Tumor Research Program, Children's Hospital Colorado, Aurora, CO, USA.
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3
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Ricci B, Millner TO, Pomella N, Zhang X, Guglielmi L, Badodi S, Ceric D, Gemma C, Cognolato E, Zhang Y, Brandner S, Barnes MR, Marino S. Polycomb-mediated repression of EphrinA5 promotes growth and invasion of glioblastoma. Oncogene 2020; 39:2523-2538. [PMID: 31988455 PMCID: PMC7082224 DOI: 10.1038/s41388-020-1161-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 12/04/2019] [Accepted: 01/15/2020] [Indexed: 11/22/2022]
Abstract
Glioblastoma (GBM) is the most common and most aggressive intrinsic brain tumour in adults. Integrated transcriptomic and epigenomic analyses of glioblastoma initiating cells (GIC) in a mouse model uncovered a novel epigenetic regulation of EfnA5. In this model, Bmi1 enhances H3K27me3 at the EfnA5 locus and reinforces repression of selected target genes in a cellular context-dependent fashion. EfnA5 mediates Bmi1-dependent proliferation and invasion in vitro and tumour formation in an allograft model. Importantly, we show that this novel Polycomb feed-forward loop is also active in human GIC and we provide pre-clinical evidence of druggability of the EFNA5 signalling pathway in GBM xenografts overexpressing Bmi1.
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Affiliation(s)
- Barbara Ricci
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK
| | - Thomas O Millner
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK
| | - Nicola Pomella
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK
| | - Xinyu Zhang
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK
| | - Loredana Guglielmi
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK
| | - Sara Badodi
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK
| | - Dario Ceric
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK
| | - Carolina Gemma
- Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital Campus, London, W12 0NN, UK
| | - Erica Cognolato
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK
| | - Ying Zhang
- Division of Neuropathology, The National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, Queen Square, London, WC1N 3BG, UK
| | - Sebastian Brandner
- Division of Neuropathology, The National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, Queen Square, London, WC1N 3BG, UK
| | - Michael R Barnes
- Centre for Translational Bioinformatics, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK
| | - Silvia Marino
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK.
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4
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Aldaz P, Otaegi-Ugartemendia M, Saenz-Antoñanzas A, Garcia-Puga M, Moreno-Valladares M, Flores JM, Gerovska D, Arauzo-Bravo MJ, Samprón N, Matheu A, Carrasco-Garcia E. SOX9 promotes tumor progression through the axis BMI1-p21 CIP. Sci Rep 2020; 10:357. [PMID: 31941916 PMCID: PMC6962164 DOI: 10.1038/s41598-019-57047-w] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 12/20/2019] [Indexed: 12/14/2022] Open
Abstract
The developmental regulator SOX9 is linked to cancer progression mainly as a result of its role in the regulation of cancer stem cells (CSCs). However, its activity in the differentiated cells that constitute the heterogeneous tumor bulk has not been extensively studied. In this work, we addressed this aspect in gastric cancer, glioblastoma and pancreatic adenocarcinoma. SOX9 silencing studies revealed that SOX9 is required for cancer cell survival, proliferation and evasion of senescence in vitro and tumor growth in vivo. Gain of-SOX9 function showed that high levels of SOX9 promote tumor cell proliferation in vitro and in vivo. Mechanistically, the modulation of SOX9 changed the expression of the transcriptional repressor BMI1 in the same direction in the three types of cancer, and the expression of the tumor suppressor p21CIP in the opposite direction. In agreement with this, SOX9 expression positively correlated with BMI1 levels and inversely with p21CIP in clinical samples of the different cancers. Moreover, BMI1 re-establishment in SOX9-silenced tumor cells restored cell viability and proliferation as well as decreased p21CIPin vitro and tumor growth in vivo. These results indicate that BMI1 is a critical effector of the pro-tumoral activity of SOX9 in tumor bulk cells through the repression of p21CIP. Our results highlight the relevance of the SOX9-BMI1-p21CIP axis in tumor progression, shedding novel opportunities for therapeutic development.
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Affiliation(s)
- Paula Aldaz
- Cellular Oncology Group, Biodonostia Health Research Institute, San Sebastian, Spain
| | | | | | - Mikel Garcia-Puga
- Cellular Oncology Group, Biodonostia Health Research Institute, San Sebastian, Spain
| | - Manuel Moreno-Valladares
- Cellular Oncology Group, Biodonostia Health Research Institute, San Sebastian, Spain.,Donostia Hospital, San Sebastian, Spain
| | - Juana M Flores
- Department of Animal Medicine and Surgery, Complutense University of Madrid, Madrid, Spain
| | - Daniela Gerovska
- Computational Biology and Systems Biomedicine Group, Biodonostia Health Research Institute, San Sebastian, Spain
| | - Marcos J Arauzo-Bravo
- Computational Biology and Systems Biomedicine Group, Biodonostia Health Research Institute, San Sebastian, Spain.,CIBERfes, Madrid, Spain.,IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
| | - Nicolas Samprón
- Cellular Oncology Group, Biodonostia Health Research Institute, San Sebastian, Spain.,Donostia Hospital, San Sebastian, Spain.,CIBERfes, Madrid, Spain
| | - Ander Matheu
- Cellular Oncology Group, Biodonostia Health Research Institute, San Sebastian, Spain. .,CIBERfes, Madrid, Spain. .,IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
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5
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Xiao Q, Zhao XY, Jiang RC, Chen XH, Zhu X, Chen KF, Chen SY, Zhang XL, Qin Y, Liu YH, Luo JD. Increased expression of Sonic hedgehog restores diabetic endothelial progenitor cells and improves cardiac repair after acute myocardial infarction in diabetic mice. Int J Mol Med 2019; 44:1091-1105. [PMID: 31524224 PMCID: PMC6657988 DOI: 10.3892/ijmm.2019.4277] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Accepted: 07/03/2019] [Indexed: 12/19/2022] Open
Abstract
Damaged endothelial progenitor cells (EPCs) are associated with poor prognosis in diabetic myocardial infarction (DMI). Our previous studies revealed that an impaired Sonic hedgehog (Shh) pathway contributes to insufficient function in diabetic EPCs; however, the roles of the Shh pathway in diabetic EPC apoptosis under basal and hypoxic/ischemic conditions remain unknown. Therefore, the present study investigated whether Shh revitalized diabetic EPCs and consequently improved the deteriorative status of DMI. For this purpose, streptozotocin injection was used in male C57/BL6 mice to induce type-1 diabetes, and diabetic EPCs were isolated from the bone marrow. Apoptosis, cell function, and protein expression were investigated in EPCs in vitro. Mouse hearts were injected with adenovirus Shh-modified diabetic EPCs (DM-EPCShh) or control DM-EPCNull immediately after coronary artery ligation in vivo. Cardiac function, capillary numbers, fibrosis, and cell apoptosis were then detected. First, the in vitro results demonstrated that the apoptosis of diabetic EPCs was reduced following treatment with Shh protein for 24 h, under normal or hypoxic conditions. BMI1 proto-oncogene (Bmi1), an antiapoptotic protein found in several cells, was reduced in diabetic EPCs under normal or hypoxic conditions, but was upregulated after Shh protein stimulation. When Bmi1-siRNA was administered, the antiapoptotic effect of Shh protein was significantly reversed. In addition, p53, a Bmi1-targeted gene, was demonstrated to mediate the antiapoptotic effect of the Shh/Bmi1 pathway in diabetic EPCs. The Shh/Bmi1/p53 axis also enhanced the diabetic EPC function. In vivo, Shh-modified diabetic EPCs exhibited increased EPC retention and decreased apoptosis at 3 days post-DMI. At 14 days post-DMI, these cells presented enhanced capillary density, reduced myocardial fibrosis and improved cardiac function. In conclusion, the present results demonstrated that the Shh pathway restored diabetic EPCs through the Shh/Bmi1/p53 axis, suppressed myocardial apoptosis and improved myocardial angiogenesis, thus reducing cardiac fibrosis and finally restoring myocardial repair and cardiac function in DMI. Thus, the Shh pathway may serve as a potential target for autologous cell therapy in diabetic myocardial ischemia.
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Affiliation(s)
- Qing Xiao
- Key Laboratory of Molecular Target and Clinical Pharmacology, School of Pharmaceutical Sciences and The Fifth Affiliated Hospital, Guangzhou Medical University, Guangzhou, Guangdong 511436, P.R. China
| | - Xiao-Ya Zhao
- Key Laboratory of Molecular Target and Clinical Pharmacology, School of Pharmaceutical Sciences and The Fifth Affiliated Hospital, Guangzhou Medical University, Guangzhou, Guangdong 511436, P.R. China
| | - Ru-Chao Jiang
- Department of Pharmacology, Guangzhou Medical University, Guangzhou, Guangdong 511436, P.R. China
| | - Xiu-Hui Chen
- Department of Pharmacology, Guangzhou Medical University, Guangzhou, Guangdong 511436, P.R. China
| | - Xiang Zhu
- Department of Pharmacology, Guangzhou Medical University, Guangzhou, Guangdong 511436, P.R. China
| | - Kai-Feng Chen
- Department of Pharmacology, Guangzhou Medical University, Guangzhou, Guangdong 511436, P.R. China
| | - Sheng-Ying Chen
- Department of Pharmacology, Guangzhou Medical University, Guangzhou, Guangdong 511436, P.R. China
| | - Xiao-Ling Zhang
- Maternal and Children Hospital of Guangdong Province, Guangzhou, Guangdong 510260, P.R. China
| | - Yuan Qin
- Department of Pharmacology, Guangzhou Medical University, Guangzhou, Guangdong 511436, P.R. China
| | - Ying-Hua Liu
- Department of Pharmacology, Guangzhou Medical University, Guangzhou, Guangdong 511436, P.R. China
| | - Jian-Dong Luo
- Department of Pharmacology, Guangzhou Medical University, Guangzhou, Guangdong 511436, P.R. China
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6
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PRMT7 methylates and suppresses GLI2 binding to SUFU thereby promoting its activation. Cell Death Differ 2019; 27:15-28. [PMID: 31000813 DOI: 10.1038/s41418-019-0334-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 03/25/2019] [Accepted: 04/08/2019] [Indexed: 01/20/2023] Open
Abstract
Cellular senescence is implicated in aging or age-related diseases. Sonic hedgehog (Shh) signaling, an inducer of embryonic development, has recently been demonstrated to inhibit cellular senescence. However, the detailed mechanisms to activate Shh signaling to prevent senescence is not well understood. Here, we demonstrate that Protein arginine methyltransferase 7 (PRMT7) promotes Shh signaling via GLI2 methylation which is critical for suppression of cellular senescence. PRMT7-deficient mouse embryonic fibroblasts (MEFs) exhibited a premature cellular senescence with accompanied increase in the cell cycle inhibitors p16 and p21. PRMT7 depletion results in reduced Shh signaling activity in MEFs while PRMT7 overexpression enhances GLI2-reporter activities that are sensitive to methylation inhibition. PRMT7 interacts with and methylates GLI2 on arginine residues 225 and 227 nearby a binding region of SUFU, a negative regulator of GLI2. This methylation interferes with GLI2-SUFU binding, leading to facilitation of GLI2 nuclear accumulation and Shh signaling. Taken together, these data suggest that PRMT7 induces GLI2 methylation, reducing its binding to SUFU and increasing Shh signaling, ultimately leading to prevention of cellular senescence.
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7
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Fu Y, Dong J, You M, Cong Z, Wei L, Fu H, Wang Y, Wang Y, Chen J. Maternal di-(2-ethylhexyl) phthalate exposure inhibits cerebellar granule precursor cell proliferation via down-regulating the Shh signaling pathway in male offspring. CHEMOSPHERE 2019; 215:313-322. [PMID: 30336312 DOI: 10.1016/j.chemosphere.2018.10.040] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 10/04/2018] [Accepted: 10/06/2018] [Indexed: 06/08/2023]
Abstract
Di-(2-ethylhexyl) phthalate (DEHP) is an endocrine disrupting chemical (EDC) widely used as a plasticizer in many materials. Epidemiological investigations have shown that DEHP exposure during early development is related to cerebellar-related adverse neurodevelopmental outcomes. However, animal studies involving the effect of DEHP exposure on cerebellar development have rarely been reported and the potential mechanisms are unclear. The aim of this study was to investigate the effect of maternal DEHP exposure on the proliferation of cerebellar granule cell precursor cells (GCPs) and the mechanisms involved. Wistar rats were randomly assigned to four exposure groups and given 0, 30, 300, or 750 mg/kg/d DEHP by intragastric administration from gestational day (GD) 0 to postnatal day (PN) 21. Exposure to 300 and 750 mg/kg/d DEHP restrained GCPs proliferation and impaired neurodevelopment for males. Furthermore, exposure to 300 and 750 mg/kg/d DEHP decreased male pups protein expressions and mRNA levels of molecules related to proliferation, including Shh, Gli1, N-Myc, CyclinD1. In addition, the estrogen level and aromatase expression also reduced in male pups after maternal exposure to DEHP. However, effects on females were not obvious. These results suggested that 300 and 750 mg/kg/d DEHP exposure inhibit the proliferation of GCPs in male offspring and ultimately contribute to the impairment of neuromotor development. This, may be caused by the down-regulation of Shh signaling. And the susceptibility of male offspring to DEHP exposure may be attributed to the decreased estrogen level and aromatase expression in male pup's cerebellum.
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Affiliation(s)
- Yuanyuan Fu
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, No. 77 Puhe Road, Shenyang 110122, PR China
| | - Jing Dong
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, No. 77 Puhe Road, Shenyang 110122, PR China
| | - Mingdan You
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, No. 77 Puhe Road, Shenyang 110122, PR China
| | - Zhangzhao Cong
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, No. 77 Puhe Road, Shenyang 110122, PR China
| | - Lingling Wei
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, No. 77 Puhe Road, Shenyang 110122, PR China
| | - Hui Fu
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, No. 77 Puhe Road, Shenyang 110122, PR China
| | - Yi Wang
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, No. 77 Puhe Road, Shenyang 110122, PR China
| | - Yuan Wang
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, No. 77 Puhe Road, Shenyang 110122, PR China
| | - Jie Chen
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, No. 77 Puhe Road, Shenyang 110122, PR China.
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8
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Xiao JF, Sun QY, Ding LW, Chien W, Liu XY, Mayakonda A, Jiang YY, Loh XY, Ran XB, Doan NB, Castor B, Chia D, Said JW, Tan KT, Yang H, Fu XY, Lin DC, Koeffler HP. The c-MYC-BMI1 axis is essential for SETDB1-mediated breast tumourigenesis. J Pathol 2018; 246:89-102. [PMID: 29926931 DOI: 10.1002/path.5126] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 05/26/2018] [Accepted: 06/11/2018] [Indexed: 12/21/2022]
Abstract
Characterising the activated oncogenic signalling that leads to advanced breast cancer is of clinical importance. Here, we showed that SET domain, bifurcated 1 (SETDB1), a histone H3 lysine 9 methyltransferase, is aberrantly expressed and behaves as an oncogenic driver in breast cancer. SETDB1 enhances c-MYC and cyclin D1 expression by promoting the internal ribosome entry site (IRES)-mediated translation of MYC/CCND1 mRNA, resulting in prominent signalling of c-MYC to promote cell cycle progression, and provides a growth/self-renewal advantage to breast cancer cells. The activated c-MYC-BMI1 axis is essential for SETDB1-mediated breast tumourigenesis, because silencing of either c-MYC or BMI1 profoundly impairs the enhanced growth/colony formation conferred by SETDB1. Furthermore, c-MYC directly binds to the SETDB1 promoter region and enhances its transcription, suggesting a positive regulatory interplay between SETDB1 and c-MYC. In this study, we identified SETDB1 as a prominent oncogene and characterised the underlying mechanism whereby SETDB1 drives breast cancer, providing a therapeutic rationale for targeting SETDB1-BMI1 signalling in breast cancer. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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Affiliation(s)
- Jin-Fen Xiao
- Cancer Science Institute of Singapore, National University of Singapore, Singapore
| | - Qiao-Yang Sun
- Cancer Science Institute of Singapore, National University of Singapore, Singapore
| | - Ling-Wen Ding
- Cancer Science Institute of Singapore, National University of Singapore, Singapore
| | - Wenwen Chien
- Division of Hematology/Oncology, Cedar-Sinai Medical Center, UCLA School of Medicine, Los Angeles, CA, USA
| | - Xin-Yu Liu
- Cancer Science Institute of Singapore, National University of Singapore, Singapore
| | - Anand Mayakonda
- Cancer Science Institute of Singapore, National University of Singapore, Singapore
| | - Yan-Yi Jiang
- Cancer Science Institute of Singapore, National University of Singapore, Singapore
| | - Xin-Yi Loh
- Cancer Science Institute of Singapore, National University of Singapore, Singapore
| | - Xue-Bin Ran
- Cancer Science Institute of Singapore, National University of Singapore, Singapore
| | - Ngan B Doan
- Department of Pathology, University of California, Los Angeles, CA, USA
| | - Brandon Castor
- Department of Pathology, University of California, Los Angeles, CA, USA
| | - David Chia
- Departments of Pathology and Laboratory Medicine, University of California, Los Angeles, CA, USA
| | - Jonathan W Said
- Department of Pathology, University of California, Los Angeles, CA, USA
| | - Kar Tong Tan
- Cancer Science Institute of Singapore, National University of Singapore, Singapore
| | - Henry Yang
- Cancer Science Institute of Singapore, National University of Singapore, Singapore
| | - Xin-Yuan Fu
- Cancer Science Institute of Singapore, National University of Singapore, Singapore.,Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - De-Chen Lin
- Division of Hematology/Oncology, Cedar-Sinai Medical Center, UCLA School of Medicine, Los Angeles, CA, USA
| | - H Phillip Koeffler
- Cancer Science Institute of Singapore, National University of Singapore, Singapore.,Division of Hematology/Oncology, Cedar-Sinai Medical Center, UCLA School of Medicine, Los Angeles, CA, USA
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9
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Ganapathi M, Boles NC, Charniga C, Lotz S, Campbell M, Temple S, Morse RH. Effect of Bmi1 over-expression on gene expression in adult and embryonic murine neural stem cells. Sci Rep 2018; 8:7464. [PMID: 29749381 PMCID: PMC5945652 DOI: 10.1038/s41598-018-25921-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 04/30/2018] [Indexed: 11/13/2022] Open
Abstract
The ability of isolated neural stem cells (NSCs) to proliferate as neurospheres is indicative of their competence as stem cells, and depends critically on the polycomb group (PcG) member Bmi1: knockdown of Bmi1 results in defective proliferation and self-renewal of isolated NSCs, whereas overexpression of Bmi1 enhances these properties. Here we report genome-wide changes in gene expression in embryonic and adult NSCs (eNSCs and aNSCs) caused by overexpression of Bmi1. We find that genes whose expression is altered by perturbations in Bmi1 levels in NSCs are mostly distinct from those affected in other multipotent stem/progenitor cells, such as those from liver and lung, aside from a small core of common targets that is enriched for genes associated with cell migration and mobility. We also show that genes differing in expression between prospectively isolated quiescent and activated NSCs are not affected by Bmi1 overexpression. In contrast, a comparison of genes showing altered expression upon Bmi1 overexpression in eNSCs and in aNSCs reveals considerable overlap, in spite of their different provenances in the brain and their differing developmental programs.
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Affiliation(s)
- Mythily Ganapathi
- Laboratory of Molecular Genetics, Wadsworth Center, New York State Dept. of Health, Albany, NY, USA
| | | | | | - Steven Lotz
- Neural Stem Cell Institute, Rensselaer, NY, USA
| | | | | | - Randall H Morse
- Laboratory of Molecular Genetics, Wadsworth Center, New York State Dept. of Health, Albany, NY, USA. .,Department of Biomedical Science, University at Albany School of Public Health, Albany, NY, USA.
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10
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Hai B, Zhao Q, Deveau MA, Liu F. Delivery of Sonic Hedgehog Gene Repressed Irradiation-induced Cellular Senescence in Salivary Glands by Promoting DNA Repair and Reducing Oxidative Stress. Theranostics 2018; 8:1159-1167. [PMID: 29464006 PMCID: PMC5817117 DOI: 10.7150/thno.23373] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 12/01/2017] [Indexed: 01/15/2023] Open
Abstract
Rationale: Irreversible hypofunction of salivary glands or xerostomia is common in head and neck cancer survivors treated with radiotherapy even when various new techniques are applied to minimize the irradiation (IR) damage. This condition severely impairs the quality of life of patients and can only be temporarily relieved with current treatments. We found recently that transient expression of Sonic Hedgehog (Shh) in salivary glands after IR rescued salivary function, but the underlying mechanisms are not totally clear. Methods: We generated a mouse model of IR-induced hyposalivation, and delivered adenoviral vectors carrying Shh or control GFP gene into submandibular glands (SMGs) via retrograde ductal instillation 3 days after IR. The cellular senescence was evaluated by senescence-associated beta-galactosidase assay and the expression of senescence markers. The underlying mechanisms were explored by examining DNA damage, oxidative stress, and the expression of related genes by qRT-PCR, Western blot and immunofluorescent staining. Results: Shh gene transfer repressed IR-induced cellular senescence by promoting DNA repair and decreasing oxidative stress, which is mediated through upregulating expression of genes related to DNA repair such as survivin and miR-21 and repressing expression of pro-senescence gene Gdf15 likely downstream of miR-21. Conclusion: Repressing cellular senescence contributes to the rescue of IR-induced hyposalivation by transient activation of Hh signaling, which is related to enhanced DNA repair and decreased oxidative stress in SMGs.
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11
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Yi J, Wu J. Epigenetic regulation in medulloblastoma. Mol Cell Neurosci 2017; 87:65-76. [PMID: 29269116 DOI: 10.1016/j.mcn.2017.09.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Revised: 09/08/2017] [Accepted: 09/10/2017] [Indexed: 12/14/2022] Open
Abstract
Medulloblastoma is the most common malignant childhood brain tumor. The heterogeneous tumors are classified into four subgroups based on transcription profiles. Recent developments in genome-wide sequencing techniques have rapidly advanced the understanding of these tumors. The high percentages of somatic alterations of genes encoding chromatin regulators in all subgroups suggest that epigenetic deregulation is a major driver of medulloblastoma. In this report, we review the current understanding of epigenetic regulation in medulloblastoma with a focus on the functional studies of chromatin regulators in the initiation and progression of specific subgroups of medulloblastoma. We also discuss the potential usage of epigenetic inhibitors for medulloblastoma treatment.
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Affiliation(s)
- Jiaqing Yi
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9040, USA
| | - Jiang Wu
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9040, USA.
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12
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Hai B, Zhao Q, Qin L, Rangaraj D, Gutti VR, Liu F. Rescue Effects and Underlying Mechanisms of Intragland Shh Gene Delivery on Irradiation-Induced Hyposalivation. Hum Gene Ther 2016; 27:390-9. [PMID: 27021743 DOI: 10.1089/hum.2016.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Irreversible hypofunction of salivary glands is common in head and neck cancer survivors treated with radiotherapy and can only be temporarily relieved with current treatments. We found in an inducible sonic hedgehog (Shh) transgenic mouse model that transient activation of the Hedgehog pathway after irradiation rescued salivary gland function in males by preserving salivary stem/progenitor cells and parasympathetic innervation. To translate these findings into feasible clinical application, we evaluated the effects of Shh gene transfer to salivary glands of wild-type mice on irradiation-induced hyposalivation. Shh or control GFP gene was delivered by noninvasive retrograde ductal instillation of corresponding adenoviral vectors. In both male and female mice, Shh gene delivery efficiently activated Hedgehog/Gli signaling, and significantly improved stimulated saliva secretion and preserved saliva-producing acinar cells after irradiation. In addition to preserving parasympathetic innervation through induction of neurotrophic factors, Shh gene delivery also alleviated the irradiation damage of the microvasculature, likely via inducing angiogenic factors, but did not expand the progeny of cells responsive to Hedgehog/Gli signaling. These data indicate that transient activation of the Hedgehog pathway by gene delivery is promising to rescue salivary function after irradiation in both sexes, and the Hedgehog/Gli pathway may function mainly in cell nonautonomous manners to achieve the rescue effect.
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Affiliation(s)
- Bo Hai
- 1 Institute for Regenerative Medicine, College of Medicine, Texas A&M Health Science Center , Temple, Texas
| | - Qingguo Zhao
- 1 Institute for Regenerative Medicine, College of Medicine, Texas A&M Health Science Center , Temple, Texas
| | - Lizheng Qin
- 1 Institute for Regenerative Medicine, College of Medicine, Texas A&M Health Science Center , Temple, Texas.,2 Beijing Stomatological Hospital, Capital Medical University , Beijing, China
| | | | - Veera R Gutti
- 3 Department of Radiation Oncology, Baylor Scott & White Hospital , Temple, Texas
| | - Fei Liu
- 1 Institute for Regenerative Medicine, College of Medicine, Texas A&M Health Science Center , Temple, Texas
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13
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Dey A, Mustafi SB, Saha S, Kumar Dhar Dwivedi S, Mukherjee P, Bhattacharya R. Inhibition of BMI1 induces autophagy-mediated necroptosis. Autophagy 2016; 12:659-70. [PMID: 27050456 DOI: 10.1080/15548627.2016.1147670] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
The clonal self-renewal property conferred by BMI1 is instrumental in maintenance of not only normal stem cells but also cancer-initiating cells from several different malignancies that represent a major challenge to chemotherapy. Realizing the immense pathological significance, PTC-209, a small molecule inhibitor of BMI1 transcription has recently been described. While targeting BMI1 in various systems significantly decreases clonal growth, the mechanisms differ, are context-dependent, and somewhat unclear. We report here that genetic or pharmacological inhibition of BMI1 significantly impacts clonal growth without altering CDKN2A/INK4/ARF or CCNG2 and induces autophagy in ovarian cancer (OvCa) cells through ATP depletion. While autophagy can promote survival or induce cell death, targeting BMI1 engages the PINK1-PARK2-dependent mitochondrial pathway and induces a novel mode of nonapoptotic, necroptosis-mediated cell death. In OvCa, necroptosis is potentiated by activation of the RIPK1-RIPK3 complex that phosphorylates its downstream substrate, MLKL. Importantly, genetic or pharmacological inhibitors of autophagy or RIPK3 rescue clonal growth in BMI1 depleted cells. Thus, we have established a novel molecular link between BMI1, clonal growth, autophagy and necroptosis. In chemoresistant OvCa where apoptotic pathways are frequently impaired, necroptotic cell death modalities provide an important alternate strategy that leverage overexpression of BMI1.
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Affiliation(s)
- Anindya Dey
- a Department of Obstetrics and Gynecology , Stephenson Cancer Center, University of Oklahoma Health Science Center , Oklahoma City , OK , USA
| | - Soumyajit Banerjee Mustafi
- a Department of Obstetrics and Gynecology , Stephenson Cancer Center, University of Oklahoma Health Science Center , Oklahoma City , OK , USA
| | - Sounik Saha
- b Department of Pathology , Stephenson Cancer Center, University of Oklahoma Health Science Center , Oklahoma City , OK , USA
| | - Shailendra Kumar Dhar Dwivedi
- a Department of Obstetrics and Gynecology , Stephenson Cancer Center, University of Oklahoma Health Science Center , Oklahoma City , OK , USA
| | - Priyabrata Mukherjee
- b Department of Pathology , Stephenson Cancer Center, University of Oklahoma Health Science Center , Oklahoma City , OK , USA
| | - Resham Bhattacharya
- a Department of Obstetrics and Gynecology , Stephenson Cancer Center, University of Oklahoma Health Science Center , Oklahoma City , OK , USA.,c Department of Cell Biology , University of Oklahoma College of Medicine , Oklahoma City , OK , USA
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14
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Potential role of Shh-Gli1-BMI1 signaling pathway nexus in glioma chemoresistance. Tumour Biol 2016; 37:15107-15114. [DOI: 10.1007/s13277-016-5365-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 09/07/2016] [Indexed: 11/25/2022] Open
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15
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Sharma N, Colangelo NW, de Toledo SM, Azzam EI. Diffusible Factors Secreted by Glioblastoma and Medulloblastoma Cells Induce Oxidative Stress in Bystander Neural Stem Progenitors. ASN Neuro 2016; 8:8/4/1759091416662808. [PMID: 27511909 PMCID: PMC4984487 DOI: 10.1177/1759091416662808] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 06/24/2016] [Indexed: 12/31/2022] Open
Abstract
Harmful effects that alter the homeostasis of neural stem or progenitor cells (NSPs) can affect regenerative processes in the central nervous system. We investigated the effect of soluble factors secreted by control or 137Cs-γ-irradiated glioblastoma or medulloblastoma cells on redox-modulated endpoints in recipient human NSPs. Growth medium harvested from the nonirradiated brain tumor cells, following 24 h of growth, induced prominent oxidative stress in recipient NSPs as judged by overall increases in mitochondrial superoxide radical levels (p < .001), activation of c-jun N-terminal kinase, and decrease in the active form of FoxO3a. The induced oxidative stress was associated with phosphorylation of p53 on serine 15, a marker of DNA damage, induction of the cyclin-cyclin dependent kinase inhibitors p21Waf1 and p27Kip1, and perturbations in cell cycle progression (p < .001). These changes were also associated with increased apoptosis as determined by enhanced annexin V staining (p < .001) and caspase 8 activation (p < .05) and altered expression of critical regulators of self-renewal, proliferation, and differentiation. Exposure of the tumor cells to radiation only slightly altered the induced oxidative changes in the bystander NSPs, except for medium from irradiated medulloblastoma cells that was more potent at inducing apoptosis in the NSPs than medium from nonirradiated cells (p < .001). The elucidation of such stressful bystander effects provides avenues to understand the biochemical events underlying the development or exacerbation of degenerative outcomes associated with brain cancers. It is also relevant to tissue culture protocols whereby growth medium conditioned by tumor cells is often used to support the growth of stem cells.
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Affiliation(s)
- Neha Sharma
- Department of Radiology, New Jersey Medical School-Cancer Center, Rutgers University, NJ, USA
| | - Nicholas W Colangelo
- Department of Radiology, New Jersey Medical School-Cancer Center, Rutgers University, NJ, USA
| | - Sonia M de Toledo
- Department of Radiology, New Jersey Medical School-Cancer Center, Rutgers University, NJ, USA
| | - Edouard I Azzam
- Department of Radiology, New Jersey Medical School-Cancer Center, Rutgers University, NJ, USA
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16
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Lu L, Xu H, Luo F, Liu X, Lu X, Yang Q, Xue J, Chen C, Shi L, Liu Q. Epigenetic silencing of miR-218 by the lncRNA CCAT1, acting via BMI1, promotes an altered cell cycle transition in the malignant transformation of HBE cells induced by cigarette smoke extract. Toxicol Appl Pharmacol 2016; 304:30-41. [PMID: 27212446 DOI: 10.1016/j.taap.2016.05.012] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 05/02/2016] [Accepted: 05/18/2016] [Indexed: 01/17/2023]
Abstract
Cigarette smoking is the strongest risk factor for the development of lung cancer, the leading cause of cancer-related deaths. However, the molecular mechanisms leading to lung cancer are largely unknown. A long-noncoding RNA (lncRNA), CCAT1, regarded as cancer-associated, has been investigated extensively. Moreover, the molecular mechanisms of lncRNAs in regulation of microRNAs (miRNAs) induced by cigarette smoke remain unclear. In the present investigation, cigarette smoke extract (CSE) caused an altered cell cycle and increased CCAT1 levels and decreased miR-218 levels in human bronchial epithelial (HBE) cells. Depletion of CCAT1 attenuated the CSE-induced decreases of miR-218 levels, suggesting that miR-218 is negatively regulated by CCAT1 in HBE cells exposed to CSE. The CSE-induced increases of BMI1 levels and blocked by CCAT1 siRNA were attenuated by an miR-218 inhibitor. Moreover, in CSE-transformed HBE cells, the CSE-induced cell cycle changes and elevated neoplastic capacity were reversed by CCAT1 siRNA or BMI1 siRNA. This epigenetic silencing of miR-218 by CCAT1 induces an altered cell cycle transition through BMI1 and provides a new mechanism for CSE-induced lung carcinogenesis.
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Affiliation(s)
- Lu Lu
- Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China; The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China
| | - Hui Xu
- Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China; The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China
| | - Fei Luo
- Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China; The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China
| | - Xinlu Liu
- Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China; The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China
| | - Xiaolin Lu
- Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China; The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China
| | - Qianlei Yang
- Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China; The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China
| | - Junchao Xue
- Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China; The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China
| | - Chao Chen
- Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China; The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China
| | - Le Shi
- Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China; The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China
| | - Qizhan Liu
- Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China; The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China.
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17
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Becker M, Potapenko T, Niklaus A, Bieback K, Ho AD, Müller AM. Polycomb Protein BMI1 Regulates Osteogenic Differentiation of Human Adipose Tissue-Derived Mesenchymal Stem Cells Downstream of GSK3. Stem Cells Dev 2016; 25:922-33. [PMID: 27100571 DOI: 10.1089/scd.2015.0277] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Polycomb proteins such as the B lymphoma Mo-MLV insertion region 1 homolog (BMI1) are essential chromatin factors for the self-renewal and differentiation of embryonic and adult stem cells. BMI1 also plays a critical role in osteogenesis as Bmi1-deficient mice display a skeletal phenotype caused by the exhaustion of the mesenchymal stem cell pool. In this study, we have studied the role of BMI1 in the osteogenic differentiation of human adipose tissue-derived mesenchymal stem cells (hASCs). BMI1 protein, but not RNA levels, increases during in vitro osteogenic differentiation of hASCs. Overexpression of BMI1 leads to an osteogenic priming of hASCs under nondifferentiating conditions and enhanced osteogenesis upon differentiation, along with increased BMP2 and WNT11 expressions. Conversely, knockdown of BMI1 expression reduces osteogenic differentiation. Furthermore, our studies indicate that during osteogenic differentiation of hASCs, BMI1 is a downstream target of GSK3 signaling. BMI1, therefore, acts as a pro-osteogenic differentiation factor in hASCs and hence it is a promising target for active modulation of hASC-derived osteogenesis.
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Affiliation(s)
- Matthias Becker
- 1 Institute for Medical Radiation and Cell Research (MSZ), Center of Experimental Molecular Medicine (ZEMM) , Würzburg, Germany
| | - Tamara Potapenko
- 1 Institute for Medical Radiation and Cell Research (MSZ), Center of Experimental Molecular Medicine (ZEMM) , Würzburg, Germany
| | - Andrea Niklaus
- 1 Institute for Medical Radiation and Cell Research (MSZ), Center of Experimental Molecular Medicine (ZEMM) , Würzburg, Germany
| | - Karen Bieback
- 2 Institute of Transfusion Medicine and Immunology, Medical Faculty Mannheim, University of Heidelberg , German Red Cross Blood Service Baden-Württemberg-Hessen, Mannheim, Germany
| | - Anthony D Ho
- 3 Department of Internal Medicine V, Heidelberg University Hospital , Heidelberg, Germany
| | - Albrecht M Müller
- 1 Institute for Medical Radiation and Cell Research (MSZ), Center of Experimental Molecular Medicine (ZEMM) , Würzburg, Germany
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18
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Men Y, Zhang A, Li H, Jin Y, Sun X, Li H, Gao J. LKB1 Regulates Cerebellar Development by Controlling Sonic Hedgehog-mediated Granule Cell Precursor Proliferation and Granule Cell Migration. Sci Rep 2015; 5:16232. [PMID: 26549569 PMCID: PMC4637891 DOI: 10.1038/srep16232] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 10/12/2015] [Indexed: 02/04/2023] Open
Abstract
The Liver Kinase B1 (LKB1) gene plays crucial roles in cell differentiation, proliferation and the establishment of cell polarity. We created LKB1 conditional knockout mice (LKB1Atoh1 CKO) to investigate the function of LKB1 in cerebellar development. The LKB1Atoh1 CKO mice displayed motor dysfunction. In the LKB1Atoh1 CKO cerebellum, the overall structure had a larger volume and morelobules. LKB1 inactivationled to an increased proliferation of granule cell precursors (GCPs), aberrant granule cell migration and overproduction of unipolar brush cells. To investigate the mechanism underlying the abnormal foliation, we examined sonic hedgehog signalling (Shh) by testing its transcriptional mediators, the Gli proteins, which regulate the GCPs proliferation and cerebellar foliation during cerebellar development. The expression levels of Gli genes were significantly increased in the mutant cerebellum. In vitro assays showed that the proliferation of cultured GCPs from mutant cerebellum significantly increased, whereas the proliferation of mutant GCPs significantly decreased in the presence of a Shh inhibitor GDC-0049. Thus, LKB1 deficiency in the LKB1Atoh1 CKO mice enhanced Shh signalling, leading to the excessive GCP proliferation and the formation of extra lobules. We proposed that LKB1 regulates cerebellar development by controlling GCPs proliferation through Shh signalling during cerebellar development.
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Affiliation(s)
- Yuqin Men
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan 250100, China
| | - Aizhen Zhang
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan 250100, China
| | - Haixiang Li
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan 250100, China
| | - Yecheng Jin
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan 250100, China
| | - Xiaoyang Sun
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan 250100, China
| | - Huashun Li
- SARITEX Center for Stem Cell, Engineering Translational Medicine, Shanghai East Hospital, Advanced Institute of Translational Medicine, Tongji University School of Medicine, Shanghai 200123, China.,Center for Stem Cell&Nano-Medicine, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 200123, China.,Shenzhen Key Laboratory for Molecular Biology of Neural Development, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518000, Guangdong, China
| | - Jiangang Gao
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan 250100, China
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19
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Koo BH, Kim Y, Je Cho Y, Kim DS. Distinct roles of transforming growth factor-β signaling and transforming growth factor-β receptor inhibitor SB431542 in the regulation of p21 expression. Eur J Pharmacol 2015; 764:413-423. [PMID: 26187313 DOI: 10.1016/j.ejphar.2015.07.032] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 07/07/2015] [Accepted: 07/13/2015] [Indexed: 11/23/2022]
Abstract
Transforming growth factor-β (TGF-β) has both tumor suppressive and oncogenic activities. Autocrine TGF-β signaling supports tumor survival and growth in certain types of cancer, and the TGF-β signaling pathway is a potential therapeutic target for these types of cancer. TGF-β induces p21 expression, and p21 is considered as an oncogene as well as a tumor suppressor, due to its anti-apoptotic activity. Thus, we hypothesized that autocrine TGF-β signaling maintains the expression of p21 at levels that can support cell growth. To verify this hypothesis, we sought to examine p21 expression and cell growth in various cancer cells following the inhibition of autocrine TGF-β signaling using siRNAs targeting TGF-β signaling components and SB431542, a TGF-β receptor inhibitor. Results from the present study show that p21 expression and cell growth were reduced by knockdown of TGF-β signaling components using siRNA in MDA-MB231 and A549 cells. Cell growth was also reduced in p21 siRNA-transfected cells. Downregulation of p21 expression induced cellular senescence in MDA-MB231 cells but did not induce apoptosis in both cells. These data suggest that autocrine TGF-β signaling is required to sustain p21 levels for positive regulation of cell cycle. On the other hand, treatment with SB431542 up-regulated p21 expression while inhibiting cell growth. The TGF-β signaling pathway was not associated with the SB431542-mediated induction of p21 expression. Specificity protein 1 (Sp1) was downregulated by treatment with SB431542, and p21 expression was increased by Sp1 knockdown. These findings suggest that downregulation of Sp1 expression is responsible for SB43154-induced p21 expression.
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Affiliation(s)
- Bon-Hun Koo
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Republic of Korea.
| | - Yeaji Kim
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Republic of Korea.
| | - Yang Je Cho
- R & D Center, EyeGene Inc., Seoul 120-113, Republic of Korea.
| | - Doo-Sik Kim
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Republic of Korea.
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20
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Deng W, Zhou Y, Tiwari AFY, Su H, Yang J, Zhu D, Lau VMY, Hau PM, Yip YL, Cheung ALM, Guan XY, Tsao SW. p21/Cyclin E pathway modulates anticlastogenic function of Bmi-1 in cancer cells. Int J Cancer 2014; 136:1361-70. [PMID: 25131797 PMCID: PMC4312942 DOI: 10.1002/ijc.29114] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2014] [Revised: 06/25/2014] [Accepted: 06/27/2014] [Indexed: 12/14/2022]
Abstract
Apart from regulating stem cell self-renewal, embryonic development and proliferation, Bmi-1 has been recently reported to be critical in the maintenance of genome integrity. In searching for novel mechanisms underlying the anticlastogenic function of Bmi-1, we observed, for the first time, that Bmi-1 positively regulates p21 expression. We extended the finding that Bmi-1 deficiency induced chromosome breaks in multiple cancer cell models. Interestingly, we further demonstrated that knockdown of cyclin E or ectopic overexpression of p21 rescued Bmi-1 deficiency-induced chromosome breaks. We therefore conclude that p21/cyclin E pathway is crucial in modulating the anticlastogenic function of Bmi-1. As it is well established that the overexpression of cyclin E potently induces genome instability and p21 suppresses the function of cyclin E, the novel and important implication from our findings is that Bmi-1 plays an important role in limiting genomic instability in cylin E-overexpressing cancer cells by positive regulation of p21.
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Affiliation(s)
- Wen Deng
- School of Nursing, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China; Department of Anatomy and Center for Cancer Research, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
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Kieran MW. Targeted treatment for sonic hedgehog-dependent medulloblastoma. Neuro Oncol 2014; 16:1037-47. [PMID: 24951114 PMCID: PMC4096181 DOI: 10.1093/neuonc/nou109] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 05/15/2014] [Indexed: 12/28/2022] Open
Abstract
Novel treatment options, including targeted therapies, are needed for patients with medulloblastoma (MB), especially for those with high-risk or recurrent/relapsed disease. Four major molecular subgroups of MB have been identified, one of which is characterized by activation of the sonic hedgehog (SHH) pathway. Preclinical data suggest that inhibitors of the hedgehog (Hh) pathway could become valuable treatment options for patients with this subgroup of MB. Indeed, agents targeting the positive regulator of the pathway, smoothened (SMO), have demonstrated efficacy in a subset of patients with SHH MB. However, because of resistance and the presence of mutations downstream of SMO, not all patients with SHH MB respond to SMO inhibitors. The development of agents that target these resistance mechanisms and the potential for their combination with traditional chemotherapy and SHH inhibitors will be discussed. Due to its extensive molecular heterogeneity, the future of MB treatment is in personalized therapy, which may lead to improved efficacy and reduced toxicity. This will include the development of clinically available tests that can efficiently discern the SHH subgroup. The preliminary use of these tests in clinical trials is also discussed herein.
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Affiliation(s)
- Mark W Kieran
- Pediatric Medical Neuro-Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts
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22
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Manoranjan B, Wang X, Hallett RM, Venugopal C, Mack SC, McFarlane N, Nolte SM, Scheinemann K, Gunnarsson T, Hassell JA, Taylor MD, Lee C, Triscott J, Foster CM, Dunham C, Hawkins C, Dunn SE, Singh SK. FoxG1 interacts with Bmi1 to regulate self-renewal and tumorigenicity of medulloblastoma stem cells. Stem Cells 2014; 31:1266-77. [PMID: 23592496 DOI: 10.1002/stem.1401] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2012] [Revised: 01/27/2013] [Accepted: 02/20/2013] [Indexed: 01/31/2023]
Abstract
Brain tumors represent the leading cause of childhood cancer mortality, of which medulloblastoma (MB) is the most frequent malignant tumor. Recent studies have demonstrated the presence of several MB molecular subgroups, each distinct in terms of prognosis and predicted therapeutic response. Groups 1 and 2 are characterized by relatively good clinical outcomes and activation of the Wnt and Shh pathways, respectively. In contrast, groups 3 and 4 ("non-Shh/Wnt MBs") are distinguished by metastatic disease, poor patient outcome, and lack a molecular pathway phenotype. Current gene expression platforms have not detected brain tumor-initiating cell (BTIC) self-renewal genes in groups 3 and 4 MBs as BTICs typically comprise a minority of tumor cells and may therefore go undetected on bulk tumor analyses. Since increasing BTIC frequency has been associated with increasing tumor aggressiveness and poor patient outcome, we investigated the subgroup-specific gene expression profile of candidate stem cell genes within 251 primary human MBs from four nonoverlapping MB transcriptional databases (Amsterdam, Memphis, Toronto, Boston) and 74 NanoString-subgrouped MBs (Vancouver). We assessed the functional relevance of two genes, FoxG1 and Bmi1, which were significantly enriched in non-Shh/Wnt MBs and showed these genes to mediate MB stem cell self-renewal and tumor initiation in mice. We also identified their transcriptional regulation through reciprocal promoter occupancy in CD15+ MB stem cells. Our work demonstrates the application of stem cell data gathered from genomic platforms to guide functional BTIC assays, which may then be used to develop novel BTIC self-renewal mechanisms amenable to therapeutic targeting.
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Ledoux MS, Dauer WT, Warner TT. Emerging common molecular pathways for primary dystonia. Mov Disord 2014; 28:968-81. [PMID: 23893453 DOI: 10.1002/mds.25547] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 05/03/2013] [Accepted: 05/06/2013] [Indexed: 12/23/2022] Open
Abstract
The dystonias are a group of hyperkinetic movement disorders whose principal cause is neuron dysfunction at 1 or more interconnected nodes of the motor system. The study of genes and proteins that cause familial dystonia provides critical information about the cellular pathways involved in this dysfunction, which disrupts the motor pathways at the systems level. In recent years study of the increasing number of DYT genes has implicated a number of cell functions that appear to be involved in the pathogenesis of dystonia. A review of the literature published in English-language publications available on PubMed relating to the genetics and cellular pathology of dystonia was performed. Numerous potential pathogenetic mechanisms have been identified. We describe those that fall into 3 emerging thematic groups: cell-cycle and transcriptional regulation in the nucleus, endoplasmic reticulum and nuclear envelope function, and control of synaptic function. © 2013 Movement Disorder Society.
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Affiliation(s)
- Mark S Ledoux
- Department of Neurology, University of Tennessee Health Science Center Memphis, Tennessee 38163, USA
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24
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Li CM, Yan HC, Fu HL, Xu GF, Wang XQ. Molecular cloning, sequence analysis, and function of the intestinal epithelial stem cell marker Bmi1 in pig intestinal epithelial cells1. J Anim Sci 2014; 92:85-94. [DOI: 10.2527/jas.2013-7048] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Affiliation(s)
- C.-M. Li
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou 510642, China
| | - H.-C. Yan
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou 510642, China
| | - H.-L. Fu
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou 510642, China
| | - G.-F. Xu
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou 510642, China
| | - X.-Q. Wang
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou 510642, China
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25
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HDAC inhibitors reverse acquired radio resistance of KYSE-150R esophageal carcinoma cells by modulating Bmi-1 expression. Toxicol Lett 2014. [DOI: 10.1016/j.toxlet.2013.10.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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26
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Hai B, Qin L, Yang Z, Zhao Q, Shangguan L, Ti X, Zhao Y, Kim S, Rangaraj D, Liu F. Transient activation of hedgehog pathway rescued irradiation-induced hyposalivation by preserving salivary stem/progenitor cells and parasympathetic innervation. Clin Cancer Res 2013; 20:140-150. [PMID: 24150232 DOI: 10.1158/1078-0432.ccr-13-1434] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
PURPOSE To examine the effects and mechanisms of transient activation of the Hedgehog pathway on rescuing radiotherapy-induced hyposalivation in survivors of head and neck cancer. EXPERIMENTAL DESIGN Mouse salivary glands and cultured human salivary epithelial cells were irradiated by a single 15-Gy dose. The Hedgehog pathway was transiently activated in mouse salivary glands, by briefly overexpressing the Sonic hedgehog (Shh) transgene or administrating smoothened agonist, and in human salivary epithelial cells, by infecting with adenovirus encoding Gli1. The activity of Hedgehog signaling was examined by the expression of the Ptch1-lacZ reporter and endogenous Hedgehog target genes. The salivary flow rate was measured following pilocarpine stimulation. Salivary stem/progenitor cells (SSPC), parasympathetic innervation, and expression of related genes were examined by flow cytometry, salisphere assay, immunohistochemistry, quantitative reverse transcription PCR, Western blotting, and ELISA. RESULTS Irradiation does not activate Hedgehog signaling in mouse salivary glands. Transient Shh overexpression activated the Hedgehog pathway in ductal epithelia and, after irradiation, rescued salivary function in male mice, which is related with preservation of functional SSPCs and parasympathetic innervation. The preservation of SSPCs was likely mediated by the rescue of signaling activities of the Bmi1 and Chrm1-HB-EGF pathways. The preservation of parasympathetic innervation was associated with the rescue of the expression of neurotrophic factors such as Bdnf and Nrtn. The expression of genes related with maintenance of SSPCs and parasympathetic innervation in female salivary glands and cultured human salivary epithelial cells was similarly affected by irradiation and transient Hedgehog activation. CONCLUSIONS These findings suggest that transient activation of the Hedgehog pathway has the potential to restore salivary gland function after irradiation-induced dysfunction.
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Affiliation(s)
- Bo Hai
- Institute for Regenerative Medicine at Scott & White, Molecular and Cellular Medicine Department, Texas A&M Health Science Center, Temple, Texas 76502, USA
| | - Lizheng Qin
- Institute for Regenerative Medicine at Scott & White, Molecular and Cellular Medicine Department, Texas A&M Health Science Center, Temple, Texas 76502, USA.,Beijing Stomatological Hospital, Capital Medical University, Beijing 100050, China
| | - Zhenhua Yang
- Institute for Regenerative Medicine at Scott & White, Molecular and Cellular Medicine Department, Texas A&M Health Science Center, Temple, Texas 76502, USA.,Department of Orthodontics, School of Stomatology, Fourth Military Medical University, Xi'an, Shaanxi 710032, China
| | - Qingguo Zhao
- Institute for Regenerative Medicine at Scott & White, Molecular and Cellular Medicine Department, Texas A&M Health Science Center, Temple, Texas 76502, USA
| | - Lei Shangguan
- Institute for Regenerative Medicine at Scott & White, Molecular and Cellular Medicine Department, Texas A&M Health Science Center, Temple, Texas 76502, USA.,Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, China
| | - Xinyu Ti
- Institute for Regenerative Medicine at Scott & White, Molecular and Cellular Medicine Department, Texas A&M Health Science Center, Temple, Texas 76502, USA.,Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, China
| | - Yanqiu Zhao
- Institute for Regenerative Medicine at Scott & White, Molecular and Cellular Medicine Department, Texas A&M Health Science Center, Temple, Texas 76502, USA.,Lutheran Medical Center, Brooklyn, NY 11220, USA
| | - Sangroh Kim
- Department of Radiation Oncology, Scott and White Hospital, Temple, Texas 76502, USA
| | - Dharanipathy Rangaraj
- Department of Radiation Oncology, Scott and White Hospital, Temple, Texas 76502, USA
| | - Fei Liu
- Institute for Regenerative Medicine at Scott & White, Molecular and Cellular Medicine Department, Texas A&M Health Science Center, Temple, Texas 76502, USA
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27
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Bmi1 is required for tumorigenesis in a mouse model of intestinal cancer. Oncogene 2013; 33:3742-7. [PMID: 23955081 DOI: 10.1038/onc.2013.333] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Revised: 06/21/2013] [Accepted: 06/24/2013] [Indexed: 12/19/2022]
Abstract
The epigenetic regulator BMI1 is upregulated progressively in a wide variety of human tumors including colorectal cancer. In this study, we assessed the requirement for Bmi1 in intestinal tumorigenesis using an autochthonous mouse model in which Apc was conditionally ablated in the intestinal epithelium. Germline mutation of Bmi1 significantly reduced both the number and size of small intestinal adenomas arising in this model, and it acted in a dose-dependent manner. Moreover, in contrast to wild-type controls, Bmi1(-/-) mice showed no increase in median tumor size, and a dramatic decrease in tumor number, between 3 and 4 months of age. Thus, Bmi1 is required for both progression and maintenance of small intestinal adenomas. Importantly, Bmi1 deficiency did not disrupt oncogenic events arising from Apc inactivation. Instead, the Arf tumor suppressor, a known target of Bmi1 epigenetic silencing, was upregulated in Bmi1 mutant tumors. This was accompanied by significant upregulation of p53, which was confirmed by sequencing to be wild-type, and also elevated apoptosis within the smallest Bmi1(-/-) adenomas. By crossing Arf into this cancer model, we showed that Arf is required for the induction of both p53 and apoptosis, and it is a key determinant of the ability of Bmi1 deficiency to suppress intestinal tumorigenesis. Finally, a conditional Bmi1 mutant strain was generated and used to determine the consequences of deleting Bmi1 specifically within the intestinal epithelium. Strikingly, intestinal-specific Bmi1 deletion suppressed small intestinal adenomas in a manner that was indistinguishable from germline Bmi1 deletion. Thus, we conclude that Bmi1 deficiency impairs the progression and maintenance of small intestinal tumors in a cell autonomous and highly Arf-dependent manner.
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28
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Exposure to Penicillium mycotoxins alters gene expression of enzymes involved in the epigenetic regulation of bovine macrophages (BoMacs). Mycotoxin Res 2013; 29:235-43. [DOI: 10.1007/s12550-013-0174-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 07/02/2013] [Accepted: 07/05/2013] [Indexed: 11/26/2022]
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29
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Ceccatelli S, Bose R, Edoff K, Onishchenko N, Spulber S. Long-lasting neurotoxic effects of exposure to methylmercury during development. J Intern Med 2013; 273:490-7. [PMID: 23600401 DOI: 10.1111/joim.12045] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Amongst environmental chemical contaminants, methylmercury (MeHg) remains a major concern because of its detrimental effects on developing organisms, which appear to be particularly susceptible to its toxicity. Here, we investigated the effects of low MeHg levels on the development of the nervous system using both in vitro and in vivo experimental models. In neural stem cells (NSCs), MeHg decreased proliferation and neuronal differentiation and induced cellular senescence associated with impairment in mitochondrial function and a concomitant decrease in global DNA methylation. Interestingly, the effects were heritable and could be observed in daughter NSCs never directly exposed to MeHg. By chronically exposing pregnant/lactating mice to MeHg, we found persistent behavioural changes in the male offspring, which exhibited depression-like behaviour that could be reversed by chronic treatment with the antidepressant fluoxetine. The behavioural alterations were associated with a decreased number of proliferating cells and lower expression of brain-derived neurotrophic factor (Bdnf) mRNA in the hippocampal dentate gyrus. MeHg exposure also induced long-lasting DNA hypermethylation, increased histone H3-K27 tri-methylation and decreased H3 acetylation at the Bdnf promoter IV, indicating that epigenetic mechanisms play a critical role in mediating the long-lasting effects of perinatal exposure to MeHg. Fluoxetine treatment restored the Bdnf mRNA expression levels, as well as the number of proliferating cells in the granule cell layer of the dentate gyrus, which further supports the hypothesis that links depression to impaired neurogenesis. Altogether, our findings have shown that low concentrations of MeHg induce long-lasting effects in NSCs that can potentially predispose individuals to depression, which we have reported earlier to occur in experimental animals exposed to MeHg during prenatal and early postnatal development.
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Affiliation(s)
- S Ceccatelli
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.
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30
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Bartesaghi S, Salomoni P. Tumor suppressive pathways in the control of neurogenesis. Cell Mol Life Sci 2013; 70:581-97. [PMID: 22802124 PMCID: PMC11113109 DOI: 10.1007/s00018-012-1063-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Revised: 06/16/2012] [Accepted: 06/18/2012] [Indexed: 12/16/2022]
Abstract
The generation of specialized neural cells in the developing and postnatal central nervous system is a highly regulated process, whereby neural stem cells divide to generate committed neuronal progenitors, which then withdraw from the cell cycle and start to differentiate. Cell cycle checkpoints play a major role in regulating the balance between neural stem cell expansion and differentiation. Loss of tumor suppressors involved in checkpoint control can lead to dramatic alterations of neurogenesis, thus contributing to neoplastic transformation. Here we summarize and critically discuss the existing literature on the role of tumor suppressive pathways and their regulatory networks in the control of neurogenesis and transformation.
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Affiliation(s)
- Stefano Bartesaghi
- Samantha Dickson Brain Cancer Unit, UCL Cancer Institute, 72 Huntley Street, London, WC1E 6DD UK
| | - Paolo Salomoni
- Samantha Dickson Brain Cancer Unit, UCL Cancer Institute, 72 Huntley Street, London, WC1E 6DD UK
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31
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Behesti H, Bhagat H, Dubuc AM, Taylor MD, Marino S. Bmi1 overexpression in the cerebellar granule cell lineage of mice affects cell proliferation and survival without initiating medulloblastoma formation. Dis Model Mech 2012; 6:49-63. [PMID: 23065639 PMCID: PMC3529338 DOI: 10.1242/dmm.009506] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
BMI1 is a potent inducer of neural stem cell self-renewal and neural progenitor cell proliferation during development and in adult tissue homeostasis. It is overexpressed in numerous human cancers – including medulloblastomas, in which its functional role is unclear. We generated transgenic mouse lines with targeted overexpression of Bmi1 in the cerebellar granule cell lineage, a cell type that has been shown to act as a cell of origin for medulloblastomas. Overexpression of Bmi1 in granule cell progenitors (GCPs) led to a decrease in cerebellar size due to decreased GCP proliferation and repression of the expression of cyclin genes, whereas Bmi1 overexpression in postmitotic granule cells improved cell survival in response to stress by altering the expression of genes in the mitochondrial cell death pathway and of Myc and Lef-1. Although no medulloblastomas developed in ageing cohorts of transgenic mice, crosses with Trp53−/− mice resulted in a low incidence of medulloblastoma formation. Furthermore, analysis of a large collection of primary human medulloblastomas revealed that tumours with a BMI1high TP53low molecular profile are significantly enriched in Group 4 human medulloblastomas. Our data suggest that different levels and timing of Bmi1 overexpression yield distinct cellular outcomes within the same cellular lineage. Importantly, Bmi1 overexpression at the GCP stage does not induce tumour formation, suggesting that BMI1 overexpression in GCP-derived human medulloblastomas probably occurs during later stages of oncogenesis and might serve to enhance tumour cell survival.
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Affiliation(s)
- Hourinaz Behesti
- Blizard Institute of Cell and Molecular Science, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK
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Abstract
If assessed by a number of criteria for cancer predisposition, Down's syndrome (DS) should be an overwhelmingly cancer-prone condition. Although childhood leukaemias occur more frequently in DS, paradoxically, individuals with DS have a markedly lower incidence of most solid tumours. Understanding the mechanisms that are capable of overcoming such odds could potentially open new routes for cancer prevention and therapy. In this Opinion article, we discuss recent reports that suggest unique and only partially understood mechanisms behind this paradox, including tumour repression, anti-angiogenic effects and stem cell ageing and availability.
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Affiliation(s)
- Dean Nižetić
- The Barts and The London School of Medicine and Dentistry, The Blizard Institute, Centre for Paediatrics, and Stem Cell Laboratory, National Centre for Bowel Research and Surgical Innovation, Queen Mary University of London, UK.
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33
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Bose R, Onishchenko N, Edoff K, Janson Lang AM, Ceccatelli S. Inherited effects of low-dose exposure to methylmercury in neural stem cells. Toxicol Sci 2012; 130:383-90. [PMID: 22918959 DOI: 10.1093/toxsci/kfs257] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Methylmercury (MeHg) is an environmental contaminant with recognized neurotoxic effects, particularly to the developing nervous system. In the present study, we show that nanomolar concentrations of MeHg can induce long-lasting effects in neural stem cells (NSCs). We investigated short-term direct and long-term inherited effects of exposure to MeHg (2.5 or 5.0 nM) using primary cultures of rat embryonic cortical NSCs. We found that MeHg had no adverse effect on cell viability but reduced NSC proliferation and altered the expression of cell cycle regulators (p16 and p21) and senescence-associated markers. In addition, we demonstrated a decrease in global DNA methylation in the exposed cells, indicating that epigenetic changes may be involved in the mechanisms underlying the MeHg-induced effects. These changes were observed in cells directly exposed to MeHg (parent cells) and in their daughter cells cultured under MeHg-free conditions. In agreement with our in vitro data, a trend was found for decreased cell proliferation in the subgranular zone in the hippocampi of adult mice exposed to low doses of MeHg during the perinatal period. Interestingly, this impaired proliferation had a measurable impact on the total number of neurons in the hippocampal dentate gyrus. Importantly, this effect could be reversed by chronic antidepressant treatment. Our study provides novel evidence for programming effects induced by MeHg in NSCs and supports the idea that developmental exposure to low levels of MeHg may result in long-term consequences predisposing to neurodevelopmental disorders and/or neurodegeneration.
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Affiliation(s)
- Raj Bose
- Department of Neuroscience, Karolinska Institutet, 17177 Stockholm, Sweden
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34
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GFAP-Cre-mediated transgenic activation of Bmi1 results in pituitary tumors. PLoS One 2012; 7:e35943. [PMID: 22574128 PMCID: PMC3344841 DOI: 10.1371/journal.pone.0035943] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Accepted: 03/28/2012] [Indexed: 01/12/2023] Open
Abstract
Bmi1 is a member of the polycomb repressive complex 1 and plays different roles during embryonic development, depending on the developmental context. Bmi1 over expression is observed in many types of cancer, including tumors of astroglial and neural origin. Although genetic depletion of Bmi1 has been described to result in tumor inhibitory effects partly through INK4A/Arf mediated senescence and apoptosis and also through INK4A/Arf independent effects, it has not been proven that Bmi1 can be causally involved in the formation of these tumors. To see whether this is the case, we developed two conditional Bmi1 transgenic models that were crossed with GFAP-Cre mice to activate transgenic expression in neural and glial lineages. We show here that these mice generate intermediate and anterior lobe pituitary tumors that are positive for ACTH and beta-endorphin. Combined transgenic expression of Bmi1 together with conditional loss of Rb resulted in pituitary tumors but was insufficient to induce medulloblastoma therefore indicating that the oncogenic function of Bmi1 depends on regulation of p16INK4A/Rb rather than on regulation of p19ARF/p53. Human pituitary adenomas show Bmi1 overexpression in over 50% of the cases, which indicates that Bmi1 could be causally involved in formation of these tumors similarly as in our mouse model.
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35
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Knights MJ, Kyle S, Ismail A. Characteristic features of stem cells in glioblastomas: from cellular biology to genetics. Brain Pathol 2012; 22:592-606. [PMID: 22303870 DOI: 10.1111/j.1750-3639.2012.00573.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Glioblastoma is the most common type of primary brain tumor in adults and is among the most lethal and least successfully treated solid tumors. Recently, research into the area of stem cells in brain tumors has gained momentum. However, due to the relatively new and novel hypothesis that a subpopulation of cancer cells in each malignancy has the potential for tumor initiation and repopulation, the data in this area of research are still in its infancy. This review article is aimed at attempting to bring together research carried out so far in order to build an understanding of glioblastoma stem cells (GSCs). Initially, we consider GSCs at a morphological and cellular level, and then discuss important cell markers, signaling pathways and genetics. Furthermore, we highlight the difficulties associated with what some of the evidence indicates and what collectively the studies contribute to further defining the interpretation of GSCs.
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Affiliation(s)
- Mark J Knights
- Leeds School of Medicine, University of Leeds, Leeds, UK.
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36
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Yadirgi G, Leinster V, Acquati S, Bhagat H, Shakhova O, Marino S. Conditional activation of Bmi1 expression regulates self-renewal, apoptosis, and differentiation of neural stem/progenitor cells in vitro and in vivo. Stem Cells 2011; 29:700-12. [PMID: 21305672 DOI: 10.1002/stem.614] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The Polycomb group protein Bmi1 is a key regulator of self-renewal of embryonic and adult central nervous system stem cells, and its overexpression has been shown to occur in several types of brain tumors. In a Cre/LoxP-based conditional transgenic mouse model, we show that fine-tuning of Bmi1 expression in embryonic neural stem cell (NSC) is sufficient to increase their proliferation and self-renewal potential both in vitro and in vivo. This is linked to downregulation of both the ink4a/ARF and the p21/Foxg1 axes. However, increased and ectopic proliferation induced by overexpression of Bmi1 in progenitors committed toward a neuronal lineage during embryonic cortical development, triggers apoptosis through a survivin-mediated mechanism and leads to reduced brain size. Postnatally, however, increased self-renewal capacity of neural stem/progenitor cells (NSPC) is independent of Foxg1 and resistance to apoptosis is observed in neural progenitors derived from NSC-overexpressing Bmi1. Neoplastic transformation is absent in mice-overexpressing Bmi1 aged up to 20 months. These studies provide strong evidence that fine tuning of Bmi1 expression is a viable tool to increase self-renewal capacity of NSCs both in vitro and in vivo without eliciting neoplastic transformation of these cells.
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Affiliation(s)
- Gokhan Yadirgi
- Blizard Institute of Cell and Molecular Science, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
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Mimeault M, Batra SK. Complex oncogenic signaling networks regulate brain tumor-initiating cells and their progenies: pivotal roles of wild-type EGFR, EGFRvIII mutant and hedgehog cascades and novel multitargeted therapies. Brain Pathol 2011; 21:479-500. [PMID: 21615592 DOI: 10.1111/j.1750-3639.2011.00505.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Complex signaling cross-talks between different growth factor cascades orchestrate the primary brain cancer development. Among the frequent deregulated oncogenic pathways, the ligand-activated wild-type epidermal growth factor receptor (EGFR), constitutively activated EGFRvIII mutant and sonic hedgehog pathways have attracted much attention because of their pivotal roles in pediatric medulloblastomas and adult glioblastoma multiformes (GBM) brain tumors. The enhanced expression levels and activation of EGFR, EGFRvIII mutant and hedgehog signaling elements can provide key roles for the sustained growth, migration and local invasion of brain tumor-initiating cells (BTICs) and their progenies, resistance to current therapies and disease relapse. These tumorigenic cascades also can cooperate with Wnt/β-catenin, Notch, platelet-derived growth factor (PDGF)/PDGF receptors (PDGFRs), hepatocyte growth factor (HGF)/c-Met receptor and vascular endothelial growth factor (VEGF)/VEGF receptors (VEGFRs) for the acquisition of a more malignant behavior and survival advantages by brain tumor cells during disease progression. Therefore, the simultaneous targeting of these oncogenic signaling components including wild-type EGFR, EGFRvIII mutant and hedgehog pathways may constitute a potential therapeutic approach of great clinical interest to eradicate BTICs and improve the efficacy of current clinical treatments by radiation and/or chemotherapy against aggressive and recurrent medulloblastomas and GBMs.
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Affiliation(s)
- Murielle Mimeault
- Department of Biochemistry and Molecular Biology, College of Medicine, Eppley Cancer Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Neb. 68198-5870, USA.
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Abstract
Bmi1 is a key stem cell regulatory gene implicated in the pathogenesis of many aggressive cancers, including medulloblastoma. Overexpression of Bmi1 promotes cell proliferation and is required for hedgehog (Hh) pathway-driven tumorigenesis. This study aimed to determine if Sonic hedgehog (Shh) modulates the key stem cell regulatory gene Bmi1 in childhood medulloblastoma brain tumor-initiating cells (BTICs). Although current literature suggests that there is a correlation between Shh pathway genes and Bmi1 expression, it is unclear whether there is indeed a direct regulatory mechanism. To address whether Shh induces expression of Bmi1, stem cell-enriched populations from medulloblastoma cell lines and primary samples were treated with Shh ligand and KAAD-cyclopamine (Shh antagonist). Our data indicate that Bmi1 expression positively correlates with increasing Shh ligand concentrations. Chromatin immunoprecipitation reveals that Gli1 preferentially binds to the Bmi1 promoter, and Bmi1 transcript levels are increased and decreased by Gli1 overexpression and downregulation, respectively. Knockdown experiments of Bmi1 in vitro and in vivo demonstrate that Hh signaling not only drives Bmi1 expression, but a feedback mechanism exists wherein downstream effectors of Bmi1 may, in turn, activate Hh pathway genes. These findings implicate Bmi1 and Hh as mutually indispensable pathways in medulloblastoma BTIC maintenance. Recent molecular characterization of medulloblastoma also reveals that Bmi1 is overexpressed across all subgroups of medulloblastoma, particularly in the most aggressive subtypes. Lastly, despite recent identification of BTIC markers, the molecular characterization of these cell populations remains unclear. In this work, we propose that the BTIC marker CD133 may segregate a cell population with a Hh-receptor phenotype, thus demonstrating a cell-cell interaction between the CD133+ Hh receptor cells and the CD133- Hh-secreting cells.
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Zhang X, Santuccione A, Leung C, Marino S. Differentiation of postnatal cerebellar glial progenitors is controlled by Bmi1 through BMP pathway inhibition. Glia 2011; 59:1118-31. [PMID: 21544870 DOI: 10.1002/glia.21184] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2010] [Accepted: 04/05/2011] [Indexed: 11/07/2022]
Abstract
Bmi1 is a polycomb group (Pc-G) protein involved in heritable gene repression, maintenance of cell identity, and proliferation. During the development of the central nervous system, Bmi1 is crucial for self-renewal of neural stem cells and for proliferation of neuronal (granule cell) progenitors of the cerebellum. Here, we use loss of function mouse models and in vitro assays--granule cell cultures and glial-neuronal co-cultures--to show that Bmi1 plays a crucial role in specification of glial progenitors during postnatal cerebellar development. Moreover, we demonstrate in in vitro assays that Bmi1 exerts this novel function through repression of BMP pathway and that this is independent of its known role in mediating the cellular response to Shh signaling. Thus modulation of Bmi1 expression in glial progenitors may represent a key event in determining the differentiation potential of these cells.
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Affiliation(s)
- Xinyu Zhang
- Blizard Institute of Cell and Molecular Sciences, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London E1 2AT, United Kingdom
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