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Liang S, Zhou J, Yu X, Lu S, Liu R. Neuronal conversion from glia to replenish the lost neurons. Neural Regen Res 2024; 19:1446-1453. [PMID: 38051886 PMCID: PMC10883502 DOI: 10.4103/1673-5374.386400] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 08/16/2023] [Indexed: 12/07/2023] Open
Abstract
ABSTRACT Neuronal injury, aging, and cerebrovascular and neurodegenerative diseases such as cerebral infarction, Alzheimer's disease, Parkinson's disease, frontotemporal dementia, amyotrophic lateral sclerosis, and Huntington's disease are characterized by significant neuronal loss. Unfortunately, the neurons of most mammals including humans do not possess the ability to self-regenerate. Replenishment of lost neurons becomes an appealing therapeutic strategy to reverse the disease phenotype. Transplantation of pluripotent neural stem cells can supplement the missing neurons in the brain, but it carries the risk of causing gene mutation, tumorigenesis, severe inflammation, and obstructive hydrocephalus induced by brain edema. Conversion of neural or non-neural lineage cells into functional neurons is a promising strategy for the diseases involving neuron loss, which may overcome the above-mentioned disadvantages of neural stem cell therapy. Thus far, many strategies to transform astrocytes, fibroblasts, microglia, Müller glia, NG2 cells, and other glial cells to mature and functional neurons, or for the conversion between neuronal subtypes have been developed through the regulation of transcription factors, polypyrimidine tract binding protein 1 (PTBP1), and small chemical molecules or are based on a combination of several factors and the location in the central nervous system. However, some recent papers did not obtain expected results, and discrepancies exist. Therefore, in this review, we discuss the history of neuronal transdifferentiation, summarize the strategies for neuronal replenishment and conversion from glia, especially astrocytes, and point out that biosafety, new strategies, and the accurate origin of the truly converted neurons in vivo should be focused upon in future studies. It also arises the attention of replenishing the lost neurons from glia by gene therapies such as up-regulation of some transcription factors or down-regulation of PTBP1 or drug interference therapies.
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Affiliation(s)
- Shiyu Liang
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
- School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing, China
| | - Jing Zhou
- Department of Geriatric Rehabilitation, Beijing Rehabilitation Hospital, Capital Medical University, Beijing, China
| | - Xiaolin Yu
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
| | - Shuai Lu
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
| | - Ruitian Liu
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
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2
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Yu D, Huang CJ, Tucker HO. Established and Evolving Roles of the Multifunctional Non-POU Domain-Containing Octamer-Binding Protein (NonO) and Splicing Factor Proline- and Glutamine-Rich (SFPQ). J Dev Biol 2024; 12:3. [PMID: 38248868 PMCID: PMC10801543 DOI: 10.3390/jdb12010003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 12/25/2023] [Accepted: 12/28/2023] [Indexed: 01/23/2024] Open
Abstract
It has been more than three decades since the discovery of multifunctional factors, the Non-POU-Domain-Containing Octamer-Binding Protein, NonO, and the Splicing Factor Proline- and Glutamine-Rich, SFPQ. Some of their functions, including their participation in transcriptional and posttranscriptional regulation as well as their contribution to paraspeckle subnuclear body organization, have been well documented. In this review, we focus on several other established roles of NonO and SFPQ, including their participation in the cell cycle, nonhomologous end-joining (NHEJ), homologous recombination (HR), telomere stability, childhood birth defects and cancer. In each of these contexts, the absence or malfunction of either or both NonO and SFPQ leads to either genome instability, tumor development or mental impairment.
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Affiliation(s)
- Danyang Yu
- Department of Biology, New York University in Shanghai, Shanghai 200122, China;
| | - Ching-Jung Huang
- Department of Biology, New York University in Shanghai, Shanghai 200122, China;
| | - Haley O. Tucker
- Molecular Biosciences, Institute for Cellular and Molecular Biology, University of Texas at Austin, 1 University Station A5000, Austin, TX 78712, USA
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3
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Abedeera SM, Davila-Calderon J, Haddad C, Henry B, King J, Penumutchu S, Tolbert BS. The Repurposing of Cellular Proteins during Enterovirus A71 Infection. Viruses 2023; 16:75. [PMID: 38257775 PMCID: PMC10821071 DOI: 10.3390/v16010075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Revised: 12/27/2023] [Accepted: 12/29/2023] [Indexed: 01/24/2024] Open
Abstract
Viruses pose a great threat to people's lives. Enterovirus A71 (EV-A71) infects children and infants all over the world with no FDA-approved treatment to date. Understanding the basic mechanisms of viral processes aids in selecting more efficient drug targets and designing more effective antivirals to thwart this virus. The 5'-untranslated region (5'-UTR) of the viral RNA genome is composed of a cloverleaf structure and an internal ribosome entry site (IRES). Cellular proteins that bind to the cloverleaf structure regulate viral RNA synthesis, while those that bind to the IRES also known as IRES trans-acting factors (ITAFs) regulate viral translation. In this review, we survey the cellular proteins currently known to bind the 5'-UTR and influence viral gene expression with emphasis on comparing proteins' functions and localizations pre- and post-(EV-A71) infection. A comprehensive understanding of how the host cell's machinery is hijacked and reprogrammed by the virus to facilitate its replication is crucial for developing effective antivirals.
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Affiliation(s)
- Sudeshi M. Abedeera
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; (S.M.A.); (B.H.); (S.P.)
| | - Jesse Davila-Calderon
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106, USA; (J.D.-C.); (C.H.); (J.K.)
| | - Christina Haddad
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106, USA; (J.D.-C.); (C.H.); (J.K.)
| | - Barrington Henry
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; (S.M.A.); (B.H.); (S.P.)
| | - Josephine King
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106, USA; (J.D.-C.); (C.H.); (J.K.)
| | - Srinivasa Penumutchu
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; (S.M.A.); (B.H.); (S.P.)
| | - Blanton S. Tolbert
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; (S.M.A.); (B.H.); (S.P.)
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
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4
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Wang LL, Zhang CL. Therapeutic Potential of PTBP1 Inhibition, If Any, Is Not Attributed to Glia-to-Neuron Conversion. Annu Rev Neurosci 2023; 46:1-15. [PMID: 36750409 PMCID: PMC10404630 DOI: 10.1146/annurev-neuro-092822-083410] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
A holy grail of regenerative medicine is to replenish the cells that are lost due to disease. The adult mammalian central nervous system (CNS) has, however, largely lost such a regenerative ability. An emerging strategy for the generation of new neurons is through glia-to-neuron (GtN) conversion in vivo, mainly accomplished by the regulation of fate-determining factors. When inhibited, PTBP1, a factor involved in RNA biology, was reported to induce rapid and efficient GtN conversion in multiple regions of the adult CNS. Remarkably, PTBP1 inhibition was also claimed to greatly improve behaviors of mice with neurological diseases or aging. These phenomenal claims, if confirmed, would constitute a significant advancement in regenerative medicine. Unfortunately, neither GtN conversion nor therapeutic potential via PTBP1 inhibition was validated by the results of multiple subsequent replication studies with stringent methods. Here we review these controversial studies and conclude with recommendations for examining GtN conversion in vivo and future investigations of PTBP1.
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Affiliation(s)
- Lei-Lei Wang
- Department of Molecular Biology and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA;
| | - Chun-Li Zhang
- Department of Molecular Biology and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA;
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Carico C, Placzek WJ. Reviewing PTBP1 Domain Modularity in the Pre-Genomic Era: A Foundation to Guide the Next Generation of Exploring PTBP1 Structure-Function Relationships. Int J Mol Sci 2023; 24:11218. [PMID: 37446395 DOI: 10.3390/ijms241311218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 06/28/2023] [Accepted: 07/06/2023] [Indexed: 07/15/2023] Open
Abstract
Polypyrimidine tract binding protein 1 (PTBP1) is one of the most well-described RNA binding proteins, known initially for its role as a splicing repressor before later studies revealed its numerous roles in RNA maturation, stability, and translation. While PTBP1's various biological roles have been well-described, it remains unclear how its four RNA recognition motif (RRM) domains coordinate these functions. The early PTBP1 literature saw extensive effort placed in detailing structures of each of PTBP1's RRMs, as well as their individual RNA sequence and structure preferences. However, limitations in high-throughput and high-resolution genomic approaches (i.e., next-generation sequencing had not yet been developed) precluded the functional translation of these findings into a mechanistic understanding of each RRM's contribution to overall PTBP1 function. With the emergence of new technologies, it is now feasible to begin elucidating the individual contributions of each RRM to PTBP1 biological functions. Here, we review all the known literature describing the apo and RNA bound structures of each of PTBP1's RRMs, as well as the emerging literature describing the dependence of specific RNA processing events on individual RRM domains. Our goal is to provide a framework of the structure-function context upon which to facilitate the interpretation of future studies interrogating the dynamics of PTBP1 function.
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Affiliation(s)
- Christine Carico
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - William J Placzek
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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Carico C, Cui J, Acton A, Placzek WJ. Polypyrimidine tract binding protein 1 (PTBP1) contains a novel regulatory sequence, the rBH3, that binds the pro-survival protein MCL1. J Biol Chem 2023:104778. [PMID: 37142223 DOI: 10.1016/j.jbc.2023.104778] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 04/25/2023] [Accepted: 04/27/2023] [Indexed: 05/06/2023] Open
Abstract
The maturation of RNA from its nascent transcription to ultimate utilization (e.g., translation, miR-mediated RNA silencing, etc.) involves an intricately coordinated series of biochemical reactions regulated by RNA binding proteins (RBPs). Over the past several decades, there has been extensive effort to elucidate the biological factors that control the specificity and selectivity of RNA target binding and downstream function. Polypyrimidine tract binding protein 1 (PTBP1) is an RBP that is involved in all steps of RNA maturation and serves as a key regulator of alternative splicing, and therefore understanding its regulation is of critical biologic importance. While several mechanisms of RBP specificity have been proposed (e.g., cell-specific expression of RBPs and secondary structure of target RNA), recently protein-protein interactions with individual domains of RBPs have been suggested to be important determinants of downstream function. Here we demonstrate a novel binding interaction between the first RNA recognition motif (RRM1) of PTBP1 and the pro-survival protein MCL1. Using both in silico and in vitro analyses, we demonstrate that MCL1 binds a novel regulatory sequence on RRM1, termed the rBH3. NMR spectroscopy reveals this interaction allosterically perturbs key residues in the RNA binding interface of RRM1 and negatively impacts RRM1 association with target RNA. Furthermore, pulldown of MCL1 by endogenous PTBP1 verifies that these proteins interact in an endogenous cellular environment, establishing the biological relevance of this binding event. Overall, our findings suggest a novel mechanism of regulation of PTBP1 in which a protein-protein interaction with a single RRM can impact RNA association.
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Affiliation(s)
- Christine Carico
- Department of Biochemistry and Molecular Genetics, The University of Alabama at Birmingham, Birmingham, AL 35294
| | - Jia Cui
- Department of Biochemistry and Molecular Genetics, The University of Alabama at Birmingham, Birmingham, AL 35294
| | - Alexus Acton
- Department of Biochemistry and Molecular Genetics, The University of Alabama at Birmingham, Birmingham, AL 35294
| | - William J Placzek
- Department of Biochemistry and Molecular Genetics, The University of Alabama at Birmingham, Birmingham, AL 35294.
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Chembazhi UV, Tung WS, Hwang H, Wang Y, Lalwani A, Nguyen K, Bangru S, Yee D, Chin K, Yang J, Kalsotra A, Mei W. PTBP1 controls intestinal epithelial regeneration through post-transcriptional regulation of gene expression. Nucleic Acids Res 2023; 51:2397-2414. [PMID: 36744439 PMCID: PMC10018364 DOI: 10.1093/nar/gkad042] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 01/06/2023] [Accepted: 01/17/2023] [Indexed: 02/07/2023] Open
Abstract
The intestinal epithelial regeneration is driven by intestinal stem cells under homeostatic conditions. Differentiated intestinal epithelial cells, such as Paneth cells, are capable of acquiring multipotency and contributing to regeneration upon the loss of intestinal stem cells. Paneth cells also support intestinal stem cell survival and regeneration. We report here that depletion of an RNA-binding protein named polypyrimidine tract binding protein 1 (PTBP1) in mouse intestinal epithelial cells causes intestinal stem cell death and epithelial regeneration failure. Mechanistically, we show that PTBP1 inhibits neuronal-like splicing programs in intestinal crypt cells, which is critical for maintaining intestinal stem cell stemness. This function is achieved at least in part through promoting the non-productive splicing of its paralog PTBP2. Moreover, PTBP1 inhibits the expression of an AKT inhibitor PHLDA3 in Paneth cells and permits AKT activation, which presumably maintains Paneth cell plasticity and function in supporting intestinal stem cell niche. We show that PTBP1 directly binds to a CU-rich region in the 3' UTR of Phlda3, which we demonstrate to be critical for downregulating the mRNA and protein levels of Phlda3. Our results thus reveal the multifaceted in vivo regulation of intestinal epithelial regeneration by PTBP1 at the post-transcriptional level.
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Affiliation(s)
| | | | | | - Yuexi Wang
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, IL 61802, USA
| | - Aryan Lalwani
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, IL 61802, USA
| | - Ka Lam Nguyen
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, IL 61802, USA
| | - Sushant Bangru
- Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Danielle Yee
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, IL 61802, USA
| | - Kristy Chin
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, IL 61802, USA
| | - Jing Yang
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, IL 61802, USA
| | - Auinash Kalsotra
- Correspondence may also be addressed to Auinash Kalsotra. Tel: +1 217 300 7654; Fax: +1 217 265 0385;
| | - Wenyan Mei
- To whom correspondence should be addressed. Tel: +1 217 244 4077; Fax: 217 333 4628; E-mail:
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Miao H, Wu F, Li Y, Qin C, Zhao Y, Xie M, Dai H, Yao H, Cai H, Wang Q, Song X, Li L. MALAT1 modulates alternative splicing by cooperating with the splicing factors PTBP1 and PSF. SCIENCE ADVANCES 2022; 8:eabq7289. [PMID: 36563164 PMCID: PMC9788761 DOI: 10.1126/sciadv.abq7289] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 11/21/2022] [Indexed: 06/17/2023]
Abstract
Understanding how long noncoding RNAs (lncRNAs) cooperate with splicing factors (SFs) in alternative splicing (AS) control is fundamental to human biology and disease. We show that metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a well-documented AS-implicated lncRNA, regulates AS via two SFs, polypyrimidine tract-binding protein 1 (PTBP1) and PTB-associated SF (PSF). MALAT1 stabilizes the interaction between PTBP1 and PSF, thereby forming a functional module that affects a network of AS events. The MALAT1-stabilized PTBP1/PSF interaction occurs in multiple cellular contexts; however, the functional module, relative to MALAT1 only, has more dominant pathological significance in hepatocellular carcinoma. MALAT1 also stabilizes the PSF interaction with several heterogeneous nuclear ribonucleoparticle proteins other than PTBP1, hinting a broad role in AS control. We present a model in which MALAT1 cooperates with distinct SFs for AS regulation and pose that, relative to analyses exclusively performed for lncRNAs, a comprehensive consideration of lncRNAs and their binding partners may provide more information about their biological functions.
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Affiliation(s)
- Hui Miao
- Center for Functional Genomics and Bioinformatics, Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan 610064, China
- Department of Platform and Technology, lncTAC Company Limited, Chengdu, Sichuan 610219, China
| | - Fan Wu
- Center for Functional Genomics and Bioinformatics, Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan 610064, China
- Department of Platform and Technology, lncTAC Company Limited, Chengdu, Sichuan 610219, China
| | - Yu Li
- Center for Functional Genomics and Bioinformatics, Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan 610064, China
| | - Chenyu Qin
- Center for Functional Genomics and Bioinformatics, Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan 610064, China
| | - Yongyun Zhao
- Center for Functional Genomics and Bioinformatics, Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan 610064, China
| | - Mingfeng Xie
- Center for Functional Genomics and Bioinformatics, Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan 610064, China
| | - Hongyuan Dai
- Center for Functional Genomics and Bioinformatics, Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan 610064, China
| | - Hong Yao
- Center for Functional Genomics and Bioinformatics, Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan 610064, China
- Department of Platform and Technology, lncTAC Company Limited, Chengdu, Sichuan 610219, China
| | - Haoyang Cai
- Center of Growth, Metabolism and Aging, Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan 610064, China
| | - Qianhong Wang
- The First Accredited Outpatient Department of Western General Hospital, Chengdu, Sichuan 610091, China
| | - Xu Song
- Center for Functional Genomics and Bioinformatics, Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan 610064, China
| | - Ling Li
- Center for Functional Genomics and Bioinformatics, Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan 610064, China
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Angulo J, Cáceres CJ, Contreras N, Fernández-García L, Chamond N, Ameur M, Sargueil B, López-Lastra M. Polypyrimidine-Tract-Binding Protein Isoforms Differentially Regulate the Hepatitis C Virus Internal Ribosome Entry Site. Viruses 2022; 15:8. [PMID: 36680049 PMCID: PMC9864772 DOI: 10.3390/v15010008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 12/03/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022] Open
Abstract
Translation initiation of the hepatitis C virus (HCV) mRNA depends on an internal ribosome entry site (IRES) that encompasses most of the 5'UTR and includes nucleotides of the core coding region. This study shows that the polypyrimidine-tract-binding protein (PTB), an RNA-binding protein with four RNA recognition motifs (RRMs), binds to the HCV 5'UTR, stimulating its IRES activity. There are three isoforms of PTB: PTB1, PTB2, and PTB4. Our results show that PTB1 and PTB4, but not PTB2, stimulate HCV IRES activity in HuH-7 and HEK293T cells. In HuH-7 cells, PTB1 promotes HCV IRES-mediated initiation more strongly than PTB4. Mutations in PTB1, PTB4, RRM1/RRM2, or RRM3/RRM4, which disrupt the RRM's ability to bind RNA, abrogated the protein's capacity to stimulate HCV IRES activity in HuH-7 cells. In HEK293T cells, PTB1 and PTB4 stimulate HCV IRES activity to similar levels. In HEK293T cells, mutations in RRM1/RRM2 did not impact PTB1's ability to promote HCV IRES activity; and mutations in PTB1 RRM3/RRM4 domains reduced, but did not abolish, the protein's capacity to stimulate HCV IRES activity. In HEK293T cells, mutations in PTB4 RRM1/RRM2 abrogated the protein's ability to promote HCV IRES activity, and mutations in RRM3/RRM4 have no impact on PTB4 ability to enhance HCV IRES activity. Therefore, PTB1 and PTB4 differentially stimulate the IRES activity in a cell type-specific manner. We conclude that PTB1 and PTB4, but not PTB2, act as IRES transacting factors of the HCV IRES.
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Affiliation(s)
- Jenniffer Angulo
- Laboratorio de Virología Molecular, Centro de Investigaciones Médicas, Instituto Milenio de Inmunología e Inmunoterapia, Departamento de Enfermedades Infecciosas e Inmunología Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile
- Facultad de Odontología, Universidad Finis Terrae, Santiago 7501015, Chile
| | - C. Joaquín Cáceres
- Laboratorio de Virología Molecular, Centro de Investigaciones Médicas, Instituto Milenio de Inmunología e Inmunoterapia, Departamento de Enfermedades Infecciosas e Inmunología Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile
- Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
| | - Nataly Contreras
- Laboratorio de Virología Molecular, Centro de Investigaciones Médicas, Instituto Milenio de Inmunología e Inmunoterapia, Departamento de Enfermedades Infecciosas e Inmunología Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile
- Facultad de Medicina Veterinaria y Agronomía, Universidad de Las Américas, Santiago 7500975, Chile
| | - Leandro Fernández-García
- Laboratorio de Virología Molecular, Centro de Investigaciones Médicas, Instituto Milenio de Inmunología e Inmunoterapia, Departamento de Enfermedades Infecciosas e Inmunología Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile
| | - Nathalie Chamond
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8038, Laboratoire CiTCoM, Université Paris Cité, 75006 Paris, France
| | - Melissa Ameur
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8038, Laboratoire CiTCoM, Université Paris Cité, 75006 Paris, France
| | - Bruno Sargueil
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8038, Laboratoire CiTCoM, Université Paris Cité, 75006 Paris, France
| | - Marcelo López-Lastra
- Laboratorio de Virología Molecular, Centro de Investigaciones Médicas, Instituto Milenio de Inmunología e Inmunoterapia, Departamento de Enfermedades Infecciosas e Inmunología Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile
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Duan L, Wang J, Zhang D, Yuan Y, Tang L, Zhou Y, Jiang X. Immune-Related miRNA-195-5p Inhibits the Progression of Lung Adenocarcinoma by Targeting Polypyrimidine Tract-Binding Protein 1. Front Oncol 2022; 12:862564. [PMID: 35600383 PMCID: PMC9117652 DOI: 10.3389/fonc.2022.862564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 04/07/2022] [Indexed: 11/13/2022] Open
Abstract
Purpose Lung adenocarcinoma (LUAD) is the most common type of cancer and the leading cause of cancer-related death worldwide, resulting in a huge economic and social burden. MiRNA-195-5p plays crucial roles in the initiation and progression of cancer. However, the significance of the miRNA-195-5p/polypyrimidine tract-binding protein 1 (miRNA-195-5p/PTBP1) axis in the progression of lung adenocarcinoma (LUAD) remains unclear. Methods Data were collected from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. The starBase database was employed to examine the expression of miRNA-195-5p, while the Kaplan–Meier plotter, UALCAN, and Gene Expression Profiling Interactive Analysis (GEPIA) databases were utilized to analyze the tumor stage and prognostic value of miRNA and PTBP1. Quantitative reverse transcription-polymerase chain reaction assay was conducted to detect the expression levels of miRNA-195-5p in LUAD cell lines and tissues. The effects of miRNA-195-5p on cell proliferation and migration were examined using the cell growth curve, clone information, transwell assays, and wound healing assays. Results We found that miRNA-195-5p was down-regulated in LUAD cancer and cell lines. Importantly, its low levels were related to the tumor stage, lymph node metastasis, and poor prognosis in LUAD. Overexpression of miR-195-5p significantly inhibited cell growth and migration promotes cell apoptosis. Further study revealed that PTBP1 is a target gene of miRNA-195-5p, and overexpression of miRNA-195-5p inhibited the progression of LUAD by inhibiting PTBP1 expression. MiRNA-195-5p expression was related to immune infiltration in lung adenocarcinoma. Moreover, PTBP1 was negatively correlated with diverse immune cell infiltration and drug sensitivity. Conclusion Our findings uncover a pivotal mechanism that miRNA-195-5p by modulate PTBP1 expression to inhibit the progression of LUAD. MiRNA-195-5p could be a novel diagnostic and prognostic molecular marker for LUAD.
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Affiliation(s)
- Lincan Duan
- Department of Thoracic Surgery, The Third Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Juan Wang
- Department of Thoracic Surgery, The Third Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Dahang Zhang
- Department of Thoracic Surgery, The Third Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Yixiao Yuan
- Department of Thoracic Surgery, The Third Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Lin Tang
- Department of Thoracic Surgery, The Third Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Yongchun Zhou
- Molecular Diagnostic Center, The Third Affiliated Hospital of Kunming Medical University, Kunming, China
- *Correspondence: Yongchun Zhou, ; Xiulin Jiang,
| | - Xiulin Jiang
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Kunming, China
- *Correspondence: Yongchun Zhou, ; Xiulin Jiang,
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11
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Li J, Li Y, Xu F, Sun B, Yang L, Wang H. Deubiquitinating enzyme PSMD14 facilitates gastric carcinogenesis through stabilizing PTBP1. Exp Cell Res 2022; 415:113148. [DOI: 10.1016/j.yexcr.2022.113148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 03/11/2022] [Accepted: 04/05/2022] [Indexed: 12/24/2022]
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12
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Dai S, Wang C, Zhang C, Feng L, Zhang W, Zhou X, He Y, Xia X, Chen B, Song W. PTB: Not just a polypyrimidine tract-binding protein. J Cell Physiol 2022; 237:2357-2373. [PMID: 35288937 DOI: 10.1002/jcp.30716] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 02/19/2022] [Accepted: 02/22/2022] [Indexed: 01/21/2023]
Abstract
Polypyrimidine tract-binding protein (PTB), as a member of the heterogeneous nuclear ribonucleoprotein family, functions by rapidly shuttling between the nucleus and the cytoplasm. PTB is involved in the alternative splicing of pre-messenger RNA (mRNA) and almost all steps of mRNA metabolism. PTB regulation is organ-specific; brain- or muscle-specific microRNAs and long noncoding RNAs partially contribute to regulating PTB, thereby modulating many physiological and pathological processes, such as embryonic development, cell development, spermatogenesis, and neuron growth and differentiation. Previous studies have shown that PTB knockout can inhibit tumorigenesis and development. The knockout of PTB in glial cells can be reprogrammed into functional neurons, which shows great promise in the field of nerve regeneration but is controversial.
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Affiliation(s)
- Shirui Dai
- National Clinical Research Center for Geriatric Diseases, Xiangya Hospital of Central South University, Changsha, Hunan, P. R. China.,Eye Center of Xiangya Hospital, Central South University, Changsha, Hunan, P. R. China.,Hunan Key Laboratory of Ophthalmology, Changsha, Hunan, P. R. China.,Department of Ophthalmology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, P. R. China.,Hunan Clinical Research Center of Ophthalmic Disease, Changsha, Hunan, P. R. China
| | - Chao Wang
- National Clinical Research Center for Geriatric Diseases, Xiangya Hospital of Central South University, Changsha, Hunan, P. R. China.,Eye Center of Xiangya Hospital, Central South University, Changsha, Hunan, P. R. China.,Hunan Key Laboratory of Ophthalmology, Changsha, Hunan, P. R. China
| | - Cheng Zhang
- National Clinical Research Center for Geriatric Diseases, Xiangya Hospital of Central South University, Changsha, Hunan, P. R. China.,Eye Center of Xiangya Hospital, Central South University, Changsha, Hunan, P. R. China.,Hunan Key Laboratory of Ophthalmology, Changsha, Hunan, P. R. China
| | - Lemeng Feng
- National Clinical Research Center for Geriatric Diseases, Xiangya Hospital of Central South University, Changsha, Hunan, P. R. China.,Eye Center of Xiangya Hospital, Central South University, Changsha, Hunan, P. R. China.,Hunan Key Laboratory of Ophthalmology, Changsha, Hunan, P. R. China
| | - Wulong Zhang
- National Clinical Research Center for Geriatric Diseases, Xiangya Hospital of Central South University, Changsha, Hunan, P. R. China.,Eye Center of Xiangya Hospital, Central South University, Changsha, Hunan, P. R. China.,Hunan Key Laboratory of Ophthalmology, Changsha, Hunan, P. R. China
| | - Xuezhi Zhou
- National Clinical Research Center for Geriatric Diseases, Xiangya Hospital of Central South University, Changsha, Hunan, P. R. China.,Eye Center of Xiangya Hospital, Central South University, Changsha, Hunan, P. R. China.,Hunan Key Laboratory of Ophthalmology, Changsha, Hunan, P. R. China
| | - Ye He
- National Clinical Research Center for Geriatric Diseases, Xiangya Hospital of Central South University, Changsha, Hunan, P. R. China.,Eye Center of Xiangya Hospital, Central South University, Changsha, Hunan, P. R. China.,Hunan Key Laboratory of Ophthalmology, Changsha, Hunan, P. R. China
| | - Xiaobo Xia
- National Clinical Research Center for Geriatric Diseases, Xiangya Hospital of Central South University, Changsha, Hunan, P. R. China.,Eye Center of Xiangya Hospital, Central South University, Changsha, Hunan, P. R. China.,Hunan Key Laboratory of Ophthalmology, Changsha, Hunan, P. R. China
| | - Baihua Chen
- Department of Ophthalmology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, P. R. China.,Hunan Clinical Research Center of Ophthalmic Disease, Changsha, Hunan, P. R. China
| | - Weitao Song
- National Clinical Research Center for Geriatric Diseases, Xiangya Hospital of Central South University, Changsha, Hunan, P. R. China.,Eye Center of Xiangya Hospital, Central South University, Changsha, Hunan, P. R. China.,Hunan Key Laboratory of Ophthalmology, Changsha, Hunan, P. R. China
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13
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Lee JS, Lamarche-Vane N, Richard S. Microexon alternative splicing of small GTPase regulators: Implication in central nervous system diseases. WILEY INTERDISCIPLINARY REVIEWS-RNA 2021; 13:e1678. [PMID: 34155820 DOI: 10.1002/wrna.1678] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 05/07/2021] [Accepted: 05/25/2021] [Indexed: 12/11/2022]
Abstract
Microexons are small sized (≤51 bp) exons which undergo extensive alternative splicing in neurons, microglia, embryonic stem cells, and cancer cells, giving rise to cell type specific protein isoforms. Due to their small sizes, microexons provide a unique challenge for the splicing machinery. They frequently lack exon splicer enhancers/repressors and require specialized neighboring trans-regulatory and cis-regulatory elements bound by RNA binding proteins (RBPs) for their inclusion. The functional consequences of including microexons within mRNAs have been extensively documented in the central nervous system (CNS) and aberrations in their inclusion have been observed to lead to abnormal processes. Despite the increasing evidence for microexons impacting cellular physiology within CNS, mechanistic details illustrating their functional importance in diseases of the CNS is still limited. In this review, we discuss the unique characteristics of microexons, and how RBPs participate in regulating their inclusion and exclusion during splicing. We consider recent findings of microexon alternative splicing and their implication for regulating the function of small GTPases in the context of the microglia, and we extrapolate these findings to what is known in neurons. We further discuss the emerging evidence for dysregulation of the Rho GTPase pathway in CNS diseases and the consequences contributed by the mis-splicing of microexons. This article is categorized under: RNA Processing > Splicing Mechanisms RNA Processing > Splicing Regulation/Alternative Splicing RNA in Disease and Development > RNA in Disease.
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Affiliation(s)
- Jee-San Lee
- Segal Cancer Center, Lady Davis Institute for Medical Research, Montreal, Quebec, Canada.,Department of Biochemistry, McGill University, Montreal, Quebec, Canada
| | - Nathalie Lamarche-Vane
- Research Institute of the McGill University Health Centre, Cancer Research Program, Montreal, Quebec, Canada.,Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada
| | - Stéphane Richard
- Segal Cancer Center, Lady Davis Institute for Medical Research, Montreal, Quebec, Canada.,Gerald Bronfman Department of Oncology, McGill University, Montreal, Quebec, Canada.,Department of Biochemistry, McGill University, Montreal, Quebec, Canada
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14
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Klotz-Noack K, Klinger B, Rivera M, Bublitz N, Uhlitz F, Riemer P, Lüthen M, Sell T, Kasack K, Gastl B, Ispasanie SSS, Simon T, Janssen N, Schwab M, Zuber J, Horst D, Blüthgen N, Schäfer R, Morkel M, Sers C. SFPQ Depletion Is Synthetically Lethal with BRAF V600E in Colorectal Cancer Cells. Cell Rep 2021; 32:108184. [PMID: 32966782 DOI: 10.1016/j.celrep.2020.108184] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Revised: 04/28/2020] [Accepted: 09/02/2020] [Indexed: 12/21/2022] Open
Abstract
Oncoproteins such as the BRAFV600E kinase endow cancer cells with malignant properties, but they also create unique vulnerabilities. Targeting of BRAFV600E-driven cytoplasmic signaling networks has proved ineffective, as patients regularly relapse with reactivation of the targeted pathways. We identify the nuclear protein SFPQ to be synthetically lethal with BRAFV600E in a loss-of-function shRNA screen. SFPQ depletion decreases proliferation and specifically induces S-phase arrest and apoptosis in BRAFV600E-driven colorectal and melanoma cells. Mechanistically, SFPQ loss in BRAF-mutant cancer cells triggers the Chk1-dependent replication checkpoint, results in decreased numbers and reduced activities of replication factories, and increases collision between replication and transcription. We find that BRAFV600E-mutant cancer cells and organoids are sensitive to combinations of Chk1 inhibitors and chemically induced replication stress, pointing toward future therapeutic approaches exploiting nuclear vulnerabilities induced by BRAFV600E.
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Affiliation(s)
- Kathleen Klotz-Noack
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health. Laboratory of Molecular Tumor Pathology and Systems Biology, Institute of Pathology, 10117 Berlin, Germany; German Cancer Consortium (DKTK), Partner Site Berlin and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Bertram Klinger
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health. Laboratory of Molecular Tumor Pathology and Systems Biology, Institute of Pathology, 10117 Berlin, Germany; IRI Life Sciences & Institute of Theoretical Biology, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
| | - Maria Rivera
- EPO Experimentelle Pharmakologie und Onkologie Berlin-Buch GmbH, Robert-Rössle-Str. 10, 13125 Berlin, Germany
| | - Natalie Bublitz
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health. Laboratory of Molecular Tumor Pathology and Systems Biology, Institute of Pathology, 10117 Berlin, Germany; German Cancer Consortium (DKTK), Partner Site Berlin and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Florian Uhlitz
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health. Laboratory of Molecular Tumor Pathology and Systems Biology, Institute of Pathology, 10117 Berlin, Germany; IRI Life Sciences & Institute of Theoretical Biology, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
| | - Pamela Riemer
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health. Laboratory of Molecular Tumor Pathology and Systems Biology, Institute of Pathology, 10117 Berlin, Germany
| | - Mareen Lüthen
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health. Laboratory of Molecular Tumor Pathology and Systems Biology, Institute of Pathology, 10117 Berlin, Germany; German Cancer Consortium (DKTK), Partner Site Berlin and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Thomas Sell
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health. Laboratory of Molecular Tumor Pathology and Systems Biology, Institute of Pathology, 10117 Berlin, Germany; IRI Life Sciences & Institute of Theoretical Biology, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
| | - Katharina Kasack
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health. Laboratory of Molecular Tumor Pathology and Systems Biology, Institute of Pathology, 10117 Berlin, Germany; German Cancer Consortium (DKTK), Partner Site Berlin and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Bastian Gastl
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health. Laboratory of Molecular Tumor Pathology and Systems Biology, Institute of Pathology, 10117 Berlin, Germany
| | - Sylvia S S Ispasanie
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health. Laboratory of Molecular Tumor Pathology and Systems Biology, Institute of Pathology, 10117 Berlin, Germany
| | - Tincy Simon
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health. Laboratory of Molecular Tumor Pathology and Systems Biology, Institute of Pathology, 10117 Berlin, Germany
| | - Nicole Janssen
- Dr. Margarete Fischer-Bosch - Institute of Clinical Pharmacology, Auerbachstraße 112, 70376 Stuttgart, Germany; University of Tuebingen, 72074 Tuebingen, Germany
| | - Matthias Schwab
- Dr. Margarete Fischer-Bosch - Institute of Clinical Pharmacology, Auerbachstraße 112, 70376 Stuttgart, Germany; Departments of Clinical Pharmacology, Pharmacy and Biochemistry, University of Tuebingen, Auf der Morgenstelle 8, 72074 Tuebingen, Germany; German Cancer Consortium (DKTK), Partner Site Tuebingen and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Johannes Zuber
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), 1030 Vienna, Austria; Medical University of Vienna, VBC, 1030 Vienna, Austria
| | - David Horst
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health. Laboratory of Molecular Tumor Pathology and Systems Biology, Institute of Pathology, 10117 Berlin, Germany; German Cancer Consortium (DKTK), Partner Site Berlin and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Nils Blüthgen
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health. Laboratory of Molecular Tumor Pathology and Systems Biology, Institute of Pathology, 10117 Berlin, Germany; IRI Life Sciences & Institute of Theoretical Biology, Humboldt-Universität zu Berlin, 10115 Berlin, Germany; German Cancer Consortium (DKTK), Partner Site Berlin and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Reinhold Schäfer
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health. Laboratory of Molecular Tumor Pathology and Systems Biology, Institute of Pathology, 10117 Berlin, Germany; German Cancer Consortium (DKTK), Partner Site Berlin and German Cancer Research Center (DKFZ), Heidelberg, Germany; Charité Comprehensive Cancer Center, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Chariteplatz 1, 10117 Berlin, Germany
| | - Markus Morkel
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health. Laboratory of Molecular Tumor Pathology and Systems Biology, Institute of Pathology, 10117 Berlin, Germany; German Cancer Consortium (DKTK), Partner Site Berlin and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Christine Sers
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health. Laboratory of Molecular Tumor Pathology and Systems Biology, Institute of Pathology, 10117 Berlin, Germany; German Cancer Consortium (DKTK), Partner Site Berlin and German Cancer Research Center (DKFZ), Heidelberg, Germany.
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15
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Cheng J, Çelik MH, Kundaje A, Gagneur J. MTSplice predicts effects of genetic variants on tissue-specific splicing. Genome Biol 2021; 22:94. [PMID: 33789710 PMCID: PMC8011109 DOI: 10.1186/s13059-021-02273-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Accepted: 01/14/2021] [Indexed: 12/20/2022] Open
Abstract
We develop the free and open-source model Multi-tissue Splicing (MTSplice) to predict the effects of genetic variants on splicing of cassette exons in 56 human tissues. MTSplice combines MMSplice, which models constitutive regulatory sequences, with a new neural network that models tissue-specific regulatory sequences. MTSplice outperforms MMSplice on predicting tissue-specific variations associated with genetic variants in most tissues of the GTEx dataset, with largest improvements on brain tissues. Furthermore, MTSplice predicts that autism-associated de novo mutations are enriched for variants affecting splicing specifically in the brain. We foresee that MTSplice will aid interpreting variants associated with tissue-specific disorders.
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Affiliation(s)
- Jun Cheng
- Department of Informatics, Technical University of Munich, Boltzmannstraße, Garching, 85748, Germany.
| | - Muhammed Hasan Çelik
- Department of Informatics, Technical University of Munich, Boltzmannstraße, Garching, 85748, Germany
| | - Anshul Kundaje
- Department of Computer Science, Stanford University, Stanford, CA, USA
- Department of Genetics, Stanford University, Stanford, CA, USA
| | - Julien Gagneur
- Department of Informatics, Technical University of Munich, Boltzmannstraße, Garching, 85748, Germany.
- Institute of Computational Biology, Helmholtz Zentrum München, Neuherberg, Germany.
- Institute of Human Genetics, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany.
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16
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Kim W, Kim DY, Lee KH. RNA-Binding Proteins and the Complex Pathophysiology of ALS. Int J Mol Sci 2021; 22:ijms22052598. [PMID: 33807542 PMCID: PMC7961459 DOI: 10.3390/ijms22052598] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 02/26/2021] [Accepted: 03/01/2021] [Indexed: 12/21/2022] Open
Abstract
Genetic analyses of patients with amyotrophic lateral sclerosis (ALS) have identified disease-causing mutations and accelerated the unveiling of complex molecular pathogenic mechanisms, which may be important for understanding the disease and developing therapeutic strategies. Many disease-related genes encode RNA-binding proteins, and most of the disease-causing RNA or proteins encoded by these genes form aggregates and disrupt cellular function related to RNA metabolism. Disease-related RNA or proteins interact or sequester other RNA-binding proteins. Eventually, many disease-causing mutations lead to the dysregulation of nucleocytoplasmic shuttling, the dysfunction of stress granules, and the altered dynamic function of the nucleolus as well as other membrane-less organelles. As RNA-binding proteins are usually components of several RNA-binding protein complexes that have other roles, the dysregulation of RNA-binding proteins tends to cause diverse forms of cellular dysfunction. Therefore, understanding the role of RNA-binding proteins will help elucidate the complex pathophysiology of ALS. Here, we summarize the current knowledge regarding the function of disease-associated RNA-binding proteins and their role in the dysfunction of membrane-less organelles.
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Affiliation(s)
- Wanil Kim
- Division of Cosmetic Science and Technology, Daegu Haany University, Hanuidae-ro 1, Gyeongsan, Gyeongbuk 38610, Korea;
| | - Do-Yeon Kim
- Department of Pharmacology, School of Dentistry, Kyungpook National University, Daegu 41940, Korea
- Correspondence: (D.-Y.K.); (K.-H.L.); Tel.: +82-53-660-6880 (D.-Y.K.); +82-53-819-7743 (K.-H.L.)
| | - Kyung-Ha Lee
- Division of Cosmetic Science and Technology, Daegu Haany University, Hanuidae-ro 1, Gyeongsan, Gyeongbuk 38610, Korea;
- Correspondence: (D.-Y.K.); (K.-H.L.); Tel.: +82-53-660-6880 (D.-Y.K.); +82-53-819-7743 (K.-H.L.)
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17
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Fu S, Wang Y, Li H, Chen L, Liu Q. Regulatory Networks of LncRNA MALAT-1 in Cancer. Cancer Manag Res 2020; 12:10181-10198. [PMID: 33116873 PMCID: PMC7575067 DOI: 10.2147/cmar.s276022] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 10/03/2020] [Indexed: 12/18/2022] Open
Abstract
Long noncoding (lnc)RNAs are a group of RNAs with a length greater than 200 nt that do not encode a protein but play an essential role in regulating the expression of target genes in normal biological contexts as well as pathologic processes including tumorigenesis. The lncRNA metastasis-associated lung adenocarcinoma transcript (MALAT)-1 has been widely studied in cancer. In this review, we describe the known functions of MALAT-1; its mechanisms of action; and associated signaling pathways and their clinical significance in different cancers. In most malignancies, including lung, colorectal, thyroid, and other cancers, MALAT-1 functions as an oncogene and is upregulated in tumors and tumor cell lines. MALAT-1 has a distinct mechanism of action in each cancer type and is thus at the center of large gene regulatory networks. Dysregulation of MALAT-1 affects cellular processes such as alternative splicing, epithelial–mesenchymal transition, apoptosis, and autophagy, which ultimately results in the abnormal cell proliferation, invasion, and migration that characterize cancers. In other malignancies, such as glioma and endometrial carcinoma, MALAT-1 functions as a tumor suppressor and thus forms additional regulatory networks. The current evidence indicates that MALAT-1 and its associated signaling pathways can serve as diagnostic or prognostic biomarker or therapeutic target in the treatment of many cancers.
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Affiliation(s)
- Shijian Fu
- The First Affiliated Hospital of Harbin Medical University, Harbin 150081, People's Republic of China
| | - Yanhong Wang
- Department of Laboratory Medicine, Yuebei People's Hospital of Shaoguan, The Affiliated Hospital of Shantou University, Shaoguan 512025, People's Republic of China
| | - Hang Li
- The First Affiliated Hospital of Harbin Medical University, Harbin 150081, People's Republic of China
| | - Leilei Chen
- Department of Cardiology, Beijing Anzhen Hospital, Beijing Institute of Heart Lung and Blood Vessel Disease, Capital Medical University, Beijing 100029, People's Republic of China
| | - Quanzhong Liu
- Department of Medical Genetics, Harbin Medical University, Harbin 150081, People's Republic of China
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18
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Kim W, Shin JC, Lee KH, Kim KT. PTBP1 Positively Regulates the Translation of Circadian Clock Gene, Period1. Int J Mol Sci 2020; 21:ijms21186921. [PMID: 32967200 PMCID: PMC7555454 DOI: 10.3390/ijms21186921] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 09/19/2020] [Accepted: 09/19/2020] [Indexed: 11/16/2022] Open
Abstract
Circadian oscillations of mRNAs and proteins are the main features of circadian clock genes. Among them, Period1 (Per1) is a key component in negative-feedback regulation, which shows a robust diurnal oscillation and the importance of circadian rhythm and translational regulation of circadian clock genes has been recognized. In the present study, we investigated the 5'-untranslated region (5'-UTR) of the mouse core clock gene, Per1, at the posttranscriptional level, particularly its translational regulation. The 5'-UTR of Per1 was found to promote its translation via an internal ribosomal entry site (IRES). We found that polypyrimidine tract-binding protein 1 (PTBP1) binds to the 5'-UTR of Per1 and positively regulates the IRES-mediated translation of Per1 without affecting the levels of Per1 mRNA. The reduction of PTBP1 level also decreased the endogenous levels of the PER1 protein but not of its mRNA. As for the oscillation of PER1 expression, the disruption of PTBP1 levels lowered the PER1 expression but not the phase of the oscillation. PTBP1 also changed the amplitudes of the mRNAs of other circadian clock genes, such as Cryptochrome 1 (Cry1) and Per3. Our results suggest that the PTBP1 is important for rhythmic translation of Per1 and it fine-tunes the overall circadian system.
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Affiliation(s)
- Wanil Kim
- Division of Cosmetic Science and Technology, Daegu Haany University, Hanuidae-ro 1, Gyeongsan, Gyeongbuk 38610, Korea;
| | | | - Kyung-Ha Lee
- Division of Cosmetic Science and Technology, Daegu Haany University, Hanuidae-ro 1, Gyeongsan, Gyeongbuk 38610, Korea;
- Correspondence: (K.-H.L.); (K.-T.K.); Tel.: +82-53-819-7743 (K.-H.L.); +82-54-279-2297 (K.-T.K.)
| | - Kyong-Tai Kim
- Department of Life Sciences, Pohang University of Science and Technology, Cheongam-Ro 77, Pohang, Gyeongbuk 37673, Korea
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Cheongam-Ro 77, Pohang, Gyeongbuk 37673, Korea
- Correspondence: (K.-H.L.); (K.-T.K.); Tel.: +82-53-819-7743 (K.-H.L.); +82-54-279-2297 (K.-T.K.)
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19
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Network Pharmacology Analysis and Experiments Validation of the Inhibitory Effect of JianPi Fu Recipe on Colorectal Cancer LoVo Cells Metastasis and Growth. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2020; 2020:4517483. [PMID: 32774415 PMCID: PMC7399765 DOI: 10.1155/2020/4517483] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2020] [Revised: 05/30/2020] [Accepted: 06/10/2020] [Indexed: 12/12/2022]
Abstract
Objective To analyze the active compounds, potential targets, and diseases of JianPi Fu Recipe (JPFR) based on network pharmacology and bioinformatics and verify the potential biological function and mechanism of JPFR in vitro and in vivo. Methods Network pharmacology databases including TCMSP, TCM-PTD, TCMID, and DrugBank were used to screen the active compounds and potential drug targets of JPFR. Cytoscape 3.7 software was applied to construct the interaction network between active compounds and potential targets. The DAVID online database analysis was performed to investigate the potential effective diseases and involved signaling pathways according to the results of the GO function and KEGG pathways enrichment analysis. To ensure standardization and maintain interbatch reliability of JPFR, High Performance Liquid Chromatography (HPLC) was used to establish a "chemical fingerprint." For biological function validation, the effect of JPFR on the proliferation and migration of CRC cells in vitro was investigated by CCK-8 and transwell and wound healing assay, and the effect of JPFR on the growth and metastasis of CRC cells in vivo was detected by building a lung metastasis model in nude mice and in vivo imaging. For the potential mechanism validation, the expressions of MALAT1, PTBP-2, and β-catenin in CRC cells and transplanted CRC tumors were detected by real-time PCR, western blot, and immunohistochemical staining analysis. Results According to the rules of oral bioavailability (OB) > 30% and drug-likeness (DL) > 0.18, 244 effective compounds in JPFR were screened out, as well as the corresponding 132 potential drug targets. By the analysis of DAVID database, all these key targets were associated closely with the cancer diseases such as prostate cancer, colorectal cancer, bladder cancer, small cell lung cancer, pancreatic cancer, and hepatocellular carcinoma. In addition, multiple signaling pathways were closely related to JPFR, including p53, Wnt, PI3K-Akt, IL-17, HIF-1, p38-MAPK, NF-κB, PD-L1 expression and PD-1 checkpoint pathway, VEGF, JAK-STAT, and Hippo. The systematical analysis showed that various active compounds of JPFR were closely connected with Wnt/β-catenin, EGFR, HIF-1, TGFβ/Smads, and IL6-STAT3 signaling pathway, including kaempferol, isorhamnetin, calycosin, quercetin, medicarpin, phaseol, spinasterol, hederagenin, beta-sitosterol, wighteone, luteolin, and isotrifoliol. For in vitro experiments, the migration and growth of human CRC cells were inhibited by the JPFR extract in a dose-dependent way, and the expression of MALAT1, PTBP-2, β-catenin, MMP7, c-Myc, and Cyclin D1 in CRC cells were downregulated by the JPFR extract in a dose-dependent way. For in vivo metastasis experiments, the numbers of lung metastasis were found to be decreased by the JPFR extract in a dose-dependent manner, and the expressions of metastasis-associated genes including MALAT1, PTBP-2, β-catenin, and MMP7 in the lung metastases were downregulated dose dependently by the JPFR extract. For the orthotopic transplanted tumor experiments, the JPFR extract could inhibit the growth of orthotopic transplanted tumors and downregulate the expression of c-Myc and Cyclin D1 in a dose-dependent manner. Moreover, the JPFR extract could prolong the survival time of tumor-bearing mice in a dose-dependent manner. Conclusions Through effective network pharmacology analysis, we found that JPFR contains many effective compounds which may directly target cancer-associated signaling pathways. The in vitro and in vivo experiments further confirmed that JPFR could inhibit the growth and metastasis of CRC cells by regulating β-catenin signaling-associated genes or proteins.
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20
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Fochi S, Lorenzi P, Galasso M, Stefani C, Trabetti E, Zipeto D, Romanelli MG. The Emerging Role of the RBM20 and PTBP1 Ribonucleoproteins in Heart Development and Cardiovascular Diseases. Genes (Basel) 2020; 11:genes11040402. [PMID: 32276354 PMCID: PMC7230170 DOI: 10.3390/genes11040402] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 04/04/2020] [Accepted: 04/06/2020] [Indexed: 12/17/2022] Open
Abstract
Alternative splicing is a regulatory mechanism essential for cell differentiation and tissue organization. More than 90% of human genes are regulated by alternative splicing events, which participate in cell fate determination. The general mechanisms of splicing events are well known, whereas only recently have deep-sequencing, high throughput analyses and animal models provided novel information on the network of functionally coordinated, tissue-specific, alternatively spliced exons. Heart development and cardiac tissue differentiation require thoroughly regulated splicing events. The ribonucleoprotein RBM20 is a key regulator of the alternative splicing events required for functional and structural heart properties, such as the expression of TTN isoforms. Recently, the polypyrimidine tract-binding protein PTBP1 has been demonstrated to participate with RBM20 in regulating splicing events. In this review, we summarize the updated knowledge relative to RBM20 and PTBP1 structure and molecular function; their role in alternative splicing mechanisms involved in the heart development and function; RBM20 mutations associated with idiopathic dilated cardiovascular disease (DCM); and the consequences of RBM20-altered expression or dysfunction. Furthermore, we discuss the possible application of targeting RBM20 in new approaches in heart therapies.
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21
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PTBP1-mediated regulation of AXL mRNA stability plays a role in lung tumorigenesis. Sci Rep 2019; 9:16922. [PMID: 31729427 PMCID: PMC6858377 DOI: 10.1038/s41598-019-53097-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 10/23/2019] [Indexed: 11/09/2022] Open
Abstract
AXL is expressed in many types of cancer and promotes cancer cell survival, metastasis and drug resistance. Here, we focus on identifying modulators that regulate AXL at the mRNA level. We have previously observed that the AXL promoter activity is inversely correlated with the AXL expression levels, suggesting that post-transcriptional mechanisms exist that down-regulate the expression of AXL mRNA. Here we show that the RNA binding protein PTBP1 (polypyrimidine tract-binding protein) directly targets the 5′-UTR of AXL mRNA in vitro and in vivo. Moreover, we also demonstrate that PTBP1, but not PTBP2, inhibits the expression of AXL mRNA and the RNA recognition motif 1 (RRM1) of PTBP1 is crucial for this interaction. To clarify how PTBP1 regulates AXL expression at the mRNA level, we found that, while the transcription rate of AXL was not significantly different, PTBP1 decreased the stability of AXL mRNA. In addition, over-expression of AXL may counteract the PTBP1-mediated apoptosis. Knock-down of PTBP1 expression could enhance tumor growth in animal models. Finally, PTBP1 was found to be negatively correlated with AXL expression in lung tumor tissues in Oncomine datasets and in tissue micro-array (TMA) analysis. In conclusion, we have identified a molecular mechanism of AXL expression regulation by PTBP1 through controlling the AXL mRNA stability. These findings may represent new thoughts alternative to current approaches that directly inhibit AXL signaling and may eventually help to develop novel therapeutics to avoid cancer metastasis and drug resistance.
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22
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Aldave G, Gonzalez-Huarriz M, Rubio A, Romero JP, Ravi D, Miñana B, Cuadrado-Tejedor M, García-Osta A, Verhaak R, Xipell E, Martinez-Vélez N, de la Rocha AA, Puigdelloses M, García-Moure M, Marigil M, Gállego Pérez-Larraya J, Marín-Bejar O, Huarte M, Carro MS, Ferrarese R, Belda-Iniesta C, Ayuso A, Prat-Acín R, Pastor F, Díez-Valle R, Tejada S, Alonso MM. The aberrant splicing of BAF45d links splicing regulation and transcription in glioblastoma. Neuro Oncol 2019; 20:930-941. [PMID: 29373718 DOI: 10.1093/neuonc/noy007] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Background Glioblastoma, the most aggressive primary brain tumor, is genetically heterogeneous. Alternative splicing (AS) plays a key role in numerous pathologies, including cancer. The objectives of our study were to determine whether aberrant AS could play a role in the malignant phenotype of glioma and to understand the mechanism underlying its aberrant regulation. Methods We obtained surgical samples from patients with glioblastoma who underwent 5-aminolevulinic fluorescence-guided surgery. Biopsies were taken from the tumor center as well as from adjacent normal-appearing tissue. We used a global splicing array to identify candidate genes aberrantly spliced in these glioblastoma samples. Mechanistic and functional studies were performed to elucidate the role of our top candidate splice variant, BAF45d, in glioblastoma. Results BAF45d is part of the switch/sucrose nonfermentable complex and plays a key role in the development of the CNS. The BAF45d/6A isoform is present in 85% of over 200 glioma samples that have been analyzed and contributes to the malignant glioma phenotype through the maintenance of an undifferentiated cellular state. We demonstrate that BAF45d splicing is mediated by polypyrimidine tract-binding protein 1 (PTBP1) and that BAF45d regulates PTBP1, uncovering a reciprocal interplay between RNA splicing regulation and transcription. Conclusions Our data indicate that AS is a mechanism that contributes to the malignant phenotype of glioblastoma. Understanding the consequences of this biological process will uncover new therapeutic targets for this devastating disease.
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Affiliation(s)
- Guillermo Aldave
- Division of Pediatric Neurosurgery, Department of Surgery, Texas Children's Hospital, Department of Neurosurgery, Baylor College of Medicine, Houston, Texas, USA
| | - Marisol Gonzalez-Huarriz
- Department of Pediatrics, University Hospital of Navarra, Pamplona, Navarra, Spain.,Health Research Institute of Navarra (IDISNA), Pamplona, Navarra, Spain.,Program in Solid Tumors, Foundation for Applied Medical Research, Pamplona, Navarra, Spain
| | - Angel Rubio
- CEIT and TECNUN, University of Navarra, San Sebastian, Spain
| | | | - Datta Ravi
- CEIT and TECNUN, University of Navarra, San Sebastian, Spain
| | - Belén Miñana
- Centre de Regulació Genòmica (CRG), Barcelona Institute of Science and Technology, Barcelona, Spain, Universitat Pompeu-Fabra, Barcelona, Spain
| | - Mar Cuadrado-Tejedor
- Health Research Institute of Navarra (IDISNA), Pamplona, Navarra, Spain.,Neurobiology of Alzheimer's Disease, Neurosciences Division, Center for Applied Medical Research, University of Navarra, Pamplona, Spain.,Anatomy Department, School of Medicine, University of Navarra, Pamplona, Spain
| | - Ana García-Osta
- Health Research Institute of Navarra (IDISNA), Pamplona, Navarra, Spain.,Neurobiology of Alzheimer's Disease, Neurosciences Division, Center for Applied Medical Research, University of Navarra, Pamplona, Spain
| | - Roeland Verhaak
- Department of Genomic Medicine, University of Texas MD Anderson Cancer Center, Houston, Texas, USA.,Department of Bioinformatics and Computational Biology, Division of Quantitative Sciences, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Enric Xipell
- Department of Pediatrics, University Hospital of Navarra, Pamplona, Navarra, Spain.,Health Research Institute of Navarra (IDISNA), Pamplona, Navarra, Spain.,Program in Solid Tumors, Foundation for Applied Medical Research, Pamplona, Navarra, Spain
| | - Naiara Martinez-Vélez
- Department of Pediatrics, University Hospital of Navarra, Pamplona, Navarra, Spain.,Health Research Institute of Navarra (IDISNA), Pamplona, Navarra, Spain.,Program in Solid Tumors, Foundation for Applied Medical Research, Pamplona, Navarra, Spain
| | - Arlet Acanda de la Rocha
- Department of Pediatrics, University Hospital of Navarra, Pamplona, Navarra, Spain.,Health Research Institute of Navarra (IDISNA), Pamplona, Navarra, Spain.,Program in Solid Tumors, Foundation for Applied Medical Research, Pamplona, Navarra, Spain
| | - Montserrat Puigdelloses
- Department of Pediatrics, University Hospital of Navarra, Pamplona, Navarra, Spain.,Health Research Institute of Navarra (IDISNA), Pamplona, Navarra, Spain.,Program in Solid Tumors, Foundation for Applied Medical Research, Pamplona, Navarra, Spain
| | - Marc García-Moure
- Department of Pediatrics, University Hospital of Navarra, Pamplona, Navarra, Spain.,Health Research Institute of Navarra (IDISNA), Pamplona, Navarra, Spain.,Program in Solid Tumors, Foundation for Applied Medical Research, Pamplona, Navarra, Spain
| | - Miguel Marigil
- Department of Pediatrics, University Hospital of Navarra, Pamplona, Navarra, Spain.,Health Research Institute of Navarra (IDISNA), Pamplona, Navarra, Spain.,Program in Solid Tumors, Foundation for Applied Medical Research, Pamplona, Navarra, Spain
| | - Jaime Gállego Pérez-Larraya
- Department of Pediatrics, University Hospital of Navarra, Pamplona, Navarra, Spain.,Health Research Institute of Navarra (IDISNA), Pamplona, Navarra, Spain.,Program in Solid Tumors, Foundation for Applied Medical Research, Pamplona, Navarra, Spain
| | - Oskar Marín-Bejar
- Health Research Institute of Navarra (IDISNA), Pamplona, Navarra, Spain.,Department of Gene Therapy and Regulation of Gene Expression, Center for Applied Medical Research, University of Navarra, Pamplona, Spain
| | - Maite Huarte
- Health Research Institute of Navarra (IDISNA), Pamplona, Navarra, Spain.,Department of Gene Therapy and Regulation of Gene Expression, Center for Applied Medical Research, University of Navarra, Pamplona, Spain
| | - Maria Stella Carro
- Department of Neurosurgery (Neurocenter) Universitätsklinikum Freiburg, Freiburg, Germany
| | - Roberto Ferrarese
- Department of Neurosurgery (Neurocenter) Universitätsklinikum Freiburg, Freiburg, Germany
| | | | - Angel Ayuso
- Fundación de Investigación HM Hospitales, Grupo HM, Spain.,Facultad de Medicina, Universidad CEU-San Pablo, Madrid, Spain
| | - Ricardo Prat-Acín
- Department of Neurosurgery, Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - Fernando Pastor
- Health Research Institute of Navarra (IDISNA), Pamplona, Navarra, Spain.,Program of Molecular Therapies, Aptamer Unit, Centro de Investigación Médica Aplicada, Pamplona, Spain
| | - Ricardo Díez-Valle
- Health Research Institute of Navarra (IDISNA), Pamplona, Navarra, Spain.,Program in Solid Tumors, Foundation for Applied Medical Research, Pamplona, Navarra, Spain.,Department of Neurosurgery, University Hospital of Navarra, Pamplona, Navarra, Spain
| | - Sonia Tejada
- Health Research Institute of Navarra (IDISNA), Pamplona, Navarra, Spain.,Program in Solid Tumors, Foundation for Applied Medical Research, Pamplona, Navarra, Spain.,Department of Neurosurgery, University Hospital of Navarra, Pamplona, Navarra, Spain
| | - Marta M Alonso
- Department of Pediatrics, University Hospital of Navarra, Pamplona, Navarra, Spain.,Health Research Institute of Navarra (IDISNA), Pamplona, Navarra, Spain.,Program in Solid Tumors, Foundation for Applied Medical Research, Pamplona, Navarra, Spain
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Kang H, Heo S, Shin JJ, Ji E, Tak H, Ahn S, Lee KJ, Lee EK, Kim W. A miR‐194/PTBP1/CCND3 axis regulates tumor growth in human hepatocellular carcinoma. J Pathol 2019; 249:395-408. [DOI: 10.1002/path.5325] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Revised: 06/16/2019] [Accepted: 07/11/2019] [Indexed: 01/05/2023]
Affiliation(s)
- Hoin Kang
- Department of BiochemistryThe Catholic University of Korea, College of Medicine Seoul South Korea
- Institute of Aging and Metabolic DiseasesThe Catholic University of Korea, College of Medicine Seoul South Korea
| | - Sungeun Heo
- Department of Molecular Science and TechnologyAjou University Suwon South Korea
| | - Jung Jae Shin
- Department of Molecular Science and TechnologyAjou University Suwon South Korea
| | - Eunbyul Ji
- Department of BiochemistryThe Catholic University of Korea, College of Medicine Seoul South Korea
| | - Hyosun Tak
- Department of BiochemistryThe Catholic University of Korea, College of Medicine Seoul South Korea
| | - Sojin Ahn
- Department of BiochemistryThe Catholic University of Korea, College of Medicine Seoul South Korea
| | - Kyung Jin Lee
- Department of Convergence Medicine, Asan Institute for Life SciencesUniversity of Ulsan College of Medicine Seoul South Korea
| | - Eun Kyung Lee
- Department of BiochemistryThe Catholic University of Korea, College of Medicine Seoul South Korea
- Institute of Aging and Metabolic DiseasesThe Catholic University of Korea, College of Medicine Seoul South Korea
| | - Wook Kim
- Department of Molecular Science and TechnologyAjou University Suwon South Korea
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Rawcliffe DFR, Österman L, Nordin A, Holmberg M. PTBP1 acts as a dominant repressor of the aberrant tissue-specific splicing of ISCU in hereditary myopathy with lactic acidosis. Mol Genet Genomic Med 2018; 6:887-897. [PMID: 30209894 PMCID: PMC6305642 DOI: 10.1002/mgg3.413] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 03/23/2018] [Accepted: 04/17/2018] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND Hereditary myopathy with lactic acidosis (HML) is an autosomal recessive disease caused by an intron mutation in the iron-sulfur cluster assembly (ISCU) gene. The mutation results in aberrant splicing, where part of the intron is retained in the final mRNA transcript, giving rise to a truncated nonfunctional ISCU protein. Using an ISCU mini-gene system, we have previously shown that PTBP1 can act as a repressor of the mis-splicing of ISCU, where overexpression of PTBP1 resulted in a decrease of the incorrect splicing. In this study, we wanted to, in more detail, analyze the role of PTBP1 in the regulation of endogenous ISCU mis-splicing. METHODS Overexpression and knockdown of PTBP1 was performed in myoblasts from two HML patients and a healthy control. Quantification of ISCU mis-splicing was done by qRTPCR. Biotinylated ISCU RNA, representing wildtype and mutant intron sequence, was used in a pull-down assay with nuclear extracts from myoblasts. Levels of PTBP1 in human cell lines and mice tissues were analyzed by qRTPCR and western blot. RESULTS PTBP1 overexpression in HML patient myoblasts resulted in a substantial decrease of ISCU mis-splicing while knockdown of PTBP1 resulted in a drastic increase. The effect could be observed in both patient and control myoblasts. We could also show that PTBP1 interacts with both the mutant and wild-type ISCU intron sequence, but with a higher affinity to the mutant sequence. Furthermore, low levels of PTBP1 among examined mouse tissues correlated with high levels of incorrect splicing of ISCU. CONCLUSION Our results show that PTBP1 acts as a dominant repressor of ISCU mis-splicing. We also show an inverse correlation between the levels of PTBP1 and ISCU mis-splicing, suggesting that the high level of mis-splicing in the skeletal muscle is primarily due to the low levels of PTBP1.
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Affiliation(s)
- Denise F. R. Rawcliffe
- Unit for Medical and Clinical GeneticsDepartment of Medical BiosciencesUmeå UniversityUmeåSweden
| | - Lennart Österman
- Unit for Medical and Clinical GeneticsDepartment of Medical BiosciencesUmeå UniversityUmeåSweden
| | - Angelica Nordin
- Unit for Medical and Clinical GeneticsDepartment of Medical BiosciencesUmeå UniversityUmeåSweden
| | - Monica Holmberg
- Unit for Medical and Clinical GeneticsDepartment of Medical BiosciencesUmeå UniversityUmeåSweden
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25
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Li X, Han F, Liu W, Shi X. PTBP1 promotes tumorigenesis by regulating apoptosis and cell cycle in colon cancer. Bull Cancer 2018; 105:1193-1201. [PMID: 30309622 DOI: 10.1016/j.bulcan.2018.08.013] [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: 05/04/2018] [Revised: 08/07/2018] [Accepted: 08/10/2018] [Indexed: 10/28/2022]
Abstract
Increased expression of polypyrimidine tract-binding protein 1 (PTBP1) has been observed in human ovarian tumors, glioblastomas, and breast cancer, but its biological roles in tumorigenesis is not fully clear. In the present research, we investigated the biological role of PTBP1 in colon cancer. We found that PTBP1 was overexpressed both in colon cancer cell lines and tissues. Tissue microarray analysis (TMA) indicated that low PTBP1 expression predicted a favorable overall survival for colon cancer patients. Using small interfering RNA technology, we found that down-regulation of PTBP1 significantly inhibited colon cancer cell growth/proliferation, and induced cell cycle arrest as well as apoptosis in vitro. Western blot analysis showed that siRNA PTBP1 could up-regulate the expression of cytoC, p53 and Bax as well as down-regulated p85, p-AKT, cyclinD1, CDK4 and Bcl2 compared to the control. Furthermore, Caspase-3 and PARP1 were activated when PTBP1 is knockdown. This study implies that PTBP1 plays an important role in tumorigenesis of colon cancer.
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Affiliation(s)
- Xiaona Li
- Xinxiang Second People's Hospital, Department of Pharmacy, Xinxiang, PR China
| | - Fei Han
- Army Medical University, College of Preventive Medicine, Key Laboratory of Medical Protection for Electromagnetic Radiation, Ministry of Education of China, Institute of Toxicology, Chongqing, China
| | - Wenbin Liu
- Army Medical University, College of Preventive Medicine, Key Laboratory of Medical Protection for Electromagnetic Radiation, Ministry of Education of China, Institute of Toxicology, Chongqing, China
| | - Xiaoyan Shi
- Henan University, Institute of Chinese materia medica, Kaifeng, China.
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26
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Hu J, Qian H, Xue Y, Fu XD. PTB/nPTB: master regulators of neuronal fate in mammals. BIOPHYSICS REPORTS 2018; 4:204-214. [PMID: 30310857 PMCID: PMC6153489 DOI: 10.1007/s41048-018-0066-y] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Accepted: 07/21/2018] [Indexed: 01/15/2023] Open
Abstract
PTB was initially discovered as a polypyrimidine tract-binding protein (hence the name), which corresponds to a specific RNA-binding protein associated with heterogeneous ribonucleoprotein particle (hnRNP I). The PTB family consists of three members in mammalian genomes, with PTBP1 (PTB) expressed in most cell types, PTBP2 (also known as nPTB or brPTB) exclusively found in the nervous system, and PTBP3 (also known as ROD1) predominately detected in immune cells. During neural development, PTB is down-regulated, which induces nPTB, and the expression of both PTB and nPTB becomes diminished when neurons mature. This programed switch, which largely takes place at the splicing level, is critical for the development of the nervous system, with PTB playing a central role in neuronal induction and nPTB guarding neuronal maturation. Remarkably, sequential knockdown of PTB and nPTB has been found to be necessary and sufficient to convert non-neuronal cells to the neuronal lineage. These findings, coupled with exquisite understanding of the molecular circuits regulated by these RNA-binding proteins, establish a critical foundation for their future applications in regenerative medicine.
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Affiliation(s)
- Jing Hu
- 1Department of Cellular and Molecular Medicine, University of California, La Jolla, San Diego, CA 92093-0651 USA
| | - Hao Qian
- 1Department of Cellular and Molecular Medicine, University of California, La Jolla, San Diego, CA 92093-0651 USA
| | - Yuanchao Xue
- 2Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101 China
| | - Xiang-Dong Fu
- 1Department of Cellular and Molecular Medicine, University of California, La Jolla, San Diego, CA 92093-0651 USA.,2Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101 China
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27
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Wang ZN, Liu D, Yin B, Ju WY, Qiu HZ, Xiao Y, Chen YJ, Peng XZ, Lu CM. High expression of PTBP1 promote invasion of colorectal cancer by alternative splicing of cortactin. Oncotarget 2018; 8:36185-36202. [PMID: 28404950 PMCID: PMC5482648 DOI: 10.18632/oncotarget.15873] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 01/23/2017] [Indexed: 12/22/2022] Open
Abstract
Polypyrimidine tract-binding protein 1 (PTBP1) involving in almost all steps of mRNA regulation including alternative splicing metabolism during tumorigenesis due to its RNA-binding activity. Initially, we found that high expressed PTBP1 and poor prognosis was interrelated in colorectal cancer (CRC) patients with stages II and III CRC, which widely different in prognosis and treatment, by immunohistochemistry. PTBP1 was also upregulated in colon cancer cell lines. In our study, knockdown of PTBP1 by siRNA transfection decreased cell proliferation and invasion in vitro. Denovirus shRNA knockdown of PTBP1 inhibited colorectal cancer growth in vivo. Furthermore, PTBP1 regulates alternative splicing of many target genes involving in tumorgenesis in colon cancer cells. We confirmed that the splicing of cortactin exon 11 which was only contained in cortactin isoform-a, as a PTBP1 target. Knockdown of PTBP1 decreased the expression of cortactin isoform-a by exclusion of exon 11. Also the mRNA levels of PTBP1 and cortactin isoform-a were cooperatively expressed in colorectal cancer tissues. Knocking down cortactin isoform-a significantly decreased cell migration and invasion in colorectal cancer cells. Overexpression of cortactin isoform-a could rescue PTBP1-knockdown effect of cell motility. In summary the study revealed that PTBP1 facilitates colorectal cancer migration and invasion activities by inclusion of cortactin exon 11.
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Affiliation(s)
- Zhi-Na Wang
- Department of Gastroenteology and Hepatology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Dan Liu
- Department of Gastroenteology and Hepatology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.,Department of Gastroenterology and Hepatology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Bin Yin
- National Laboratory of Meidical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Wen-Yi Ju
- National Laboratory of Meidical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Hui-Zhong Qiu
- Department of General Surgery, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Yi Xiao
- Department of General Surgery, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Yuan-Jia Chen
- Department of Gastroenteology and Hepatology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Xiao-Zhong Peng
- National Laboratory of Meidical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Chong-Mei Lu
- Department of Gastroenteology and Hepatology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
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Romero-Barrios N, Legascue MF, Benhamed M, Ariel F, Crespi M. Splicing regulation by long noncoding RNAs. Nucleic Acids Res 2018; 46:2169-2184. [PMID: 29425321 PMCID: PMC5861421 DOI: 10.1093/nar/gky095] [Citation(s) in RCA: 192] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 01/05/2018] [Accepted: 02/01/2018] [Indexed: 12/13/2022] Open
Abstract
Massive high-throughput sequencing techniques allowed the identification of thousands of noncoding RNAs (ncRNAs) and a plethora of different mRNA processing events occurring in higher organisms. Long ncRNAs can act directly as long transcripts or can be processed into active small si/miRNAs. They can modulate mRNA cleavage, translational repression or the epigenetic landscape of their target genes. Recently, certain long ncRNAs have been shown to play a crucial role in the regulation of alternative splicing in response to several stimuli or during disease. In this review, we focus on recent discoveries linking gene regulation by alternative splicing and its modulation by long and small ncRNAs.
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Affiliation(s)
- Natali Romero-Barrios
- Institute of Plant Sciences Paris-Saclay (IPS2), CNRS, INRA, Universities Paris-Sud, Evry and Paris-Diderot, Sorbonne Paris-Cite, University of Paris-Saclay, Batiment 630, 91405 Orsay, France
| | - Maria Florencia Legascue
- Instituto de Agrobiotecnología del Litoral, CONICET, Universidad Nacional del Litoral, Colectora Ruta Nacional 168 km 0, 3000 Santa Fe, Argentina
| | - Moussa Benhamed
- Institute of Plant Sciences Paris-Saclay (IPS2), CNRS, INRA, Universities Paris-Sud, Evry and Paris-Diderot, Sorbonne Paris-Cite, University of Paris-Saclay, Batiment 630, 91405 Orsay, France
| | - Federico Ariel
- Instituto de Agrobiotecnología del Litoral, CONICET, Universidad Nacional del Litoral, Colectora Ruta Nacional 168 km 0, 3000 Santa Fe, Argentina
| | - Martin Crespi
- Institute of Plant Sciences Paris-Saclay (IPS2), CNRS, INRA, Universities Paris-Sud, Evry and Paris-Diderot, Sorbonne Paris-Cite, University of Paris-Saclay, Batiment 630, 91405 Orsay, France
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Shan H, Hou P, Zhang M, Li L, Pan Y, Chen F, Jiang T, Bai J, Zheng J. PTBP1 knockdown in renal cell carcinoma inhibits cell migration, invasion and angiogenesis in vitro and metastasis in vivo via the hypoxia inducible factor-1α pathway. Int J Oncol 2018; 52:1613-1622. [PMID: 29512730 DOI: 10.3892/ijo.2018.4296] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 02/27/2018] [Indexed: 11/05/2022] Open
Abstract
Polypyrimidine tract-binding protein 1 (PTBP1), a heterogeneous nuclear ribonucleoprotein, is a multi-functional RNA-binding protein. PTBP1 participates in a number of biological processes, including maintaining cell structure and motility, immunity, protein metabolism and the cell cycle. The present study aimed to investigate the association between PTBP1 expression and the prognosis and clinicopathological characteristics of patients with renal cell cancer (RCC). The potential mechanism of action of PTBP1 in the metastasis of RCC was also investigated. The results demonstrated that PTBP1 was overexpressed in RCC tissues compared with normal renal tissues. Furthermore, PTBP1 expression was negatively associated with patient prognosis and positively associated with tumor size, pathological tumor (pT) and pathological metastasis (pM) status and tumor lymph node metastasis (TNM) stage. PTBP1 knockdown in vitro inhibited RCC cell migration, invasion, proliferation and angiogenesis, and it was demonstrated that PTBP1 affected RCC cells primarily via the hypoxia inducible factor-1α pathway. Furthermore, PTBP1 knockdown decreased RCC lung metastasis in vivo. The present study demonstrated that PTBP1 knockdown suppresses tumor progression and metastasis, indicating that PTBP1 is an important prognostic factor in RCC and that it may be developed as a novel method of treating patients with RCC.
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Affiliation(s)
- Haixia Shan
- The Fourth Clinical College of Nanjing Medical University, Nanjing, Jiangsu 211100, P.R. China
| | - Pingfu Hou
- Cancer Institute, Xuzhou Medical University, Xuzhou, Jiangsu 221002, P.R. China
| | - Meng Zhang
- Cancer Institute, Xuzhou Medical University, Xuzhou, Jiangsu 221002, P.R. China
| | - Liantao Li
- Center of Clinical Oncology, Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221002, P.R. China
| | - Yu Pan
- Cancer Institute, Xuzhou Medical University, Xuzhou, Jiangsu 221002, P.R. China
| | - Fang Chen
- Cancer Institute, Xuzhou Medical University, Xuzhou, Jiangsu 221002, P.R. China
| | - Tao Jiang
- Cancer Institute, Xuzhou Medical University, Xuzhou, Jiangsu 221002, P.R. China
| | - Jin Bai
- Cancer Institute, Xuzhou Medical University, Xuzhou, Jiangsu 221002, P.R. China
| | - Junnian Zheng
- The Fourth Clinical College of Nanjing Medical University, Nanjing, Jiangsu 211100, P.R. China
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PTBP1 and PTBP2 Repress Nonconserved Cryptic Exons. Cell Rep 2017; 17:104-113. [PMID: 27681424 DOI: 10.1016/j.celrep.2016.08.071] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 06/16/2016] [Accepted: 08/20/2016] [Indexed: 01/06/2023] Open
Abstract
The fidelity of RNA splicing is maintained by a network of factors, but the molecular mechanisms that govern this process have yet to be fully elucidated. We previously found that TDP-43, an RNA-binding protein implicated in neurodegenerative disease, utilizes UG microsatellites to repress nonconserved cryptic exons and prevent their incorporation into mRNA. Here, we report that two well-characterized splicing factors, polypyrimidine tract-binding protein 1 (PTBP1) and polypyrimidine tract-binding protein 2 (PTBP2), are also nonconserved cryptic exon repressors. In contrast to TDP-43, PTBP1 and PTBP2 utilize CU microsatellites to repress both conserved tissue-specific exons and nonconserved cryptic exons. Analysis of these conserved splicing events suggests that PTBP1 and PTBP2 repression is titrated to generate the transcriptome diversity required for neuronal differentiation. We establish that PTBP1 and PTBP2 are members of a family of cryptic exon repressors.
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Yamauchi KA, Herr AE. Subcellular western blotting of single cells. MICROSYSTEMS & NANOENGINEERING 2017; 3:16079. [PMID: 29333327 PMCID: PMC5764185 DOI: 10.1038/micronano.2016.79] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 09/28/2016] [Accepted: 10/10/2016] [Indexed: 05/04/2023]
Abstract
Although immunoassays are the de facto standard for determining subcellular protein localization in individual cells, antibody probe cross-reactivity and fixation artifacts remain confounding factors. To enhance selectivity while providing single-cell resolution, we introduce a subcellular western blotting technique capable of separately assaying proteins in the 14 pL cytoplasm and 2 pL nucleus of individual cells. To confer precision fluidic control, we describe a passive multilayer microdevice that leverages the rapid transport times afforded by miniaturization. After isolating single cells in microwells, we apply single-cell differential detergent fractionation to lyse and western blot the cytoplasmic lysate, whereas the nucleus remains intact in the microwell. Subsequently, we lyse the intact nucleus and western blot the nuclear lysate. To index each protein analysis to the originating subcellular compartment, we utilize bi-directional electrophoresis, a multidimensional separation that assays the lysate from each compartment in a distinct region of the separation axis. Single-cell bi-directional electrophoresis eliminates the need for semi-subjective image segmentation algorithms required in immunocytochemistry. The subcellular, single-cell western blot is demonstrated for six targets per cell, and successfully localizes spliceosome-associated proteins solubilized from large protein and RNA complexes, even for closely sized proteins (a 7 kDa difference). Measurement of NF-κB translocation dynamics in unfixed cells at 15-min intervals demonstrates reduced technical variance compared with immunofluorescence. This chemical cytometry assay directly measures the nucleocytoplasmic protein distribution in individual unfixed cells, thus providing insight into protein signaling in heterogeneous cell populations.
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Affiliation(s)
- Kevin A. Yamauchi
- Department of Bioengineering, University of California, Berkeley, CA 94720, USA
- The UC Berkeley—UCSF Graduate Program in Bioengineering, University of California, Berkeley, CA 94720, USA
| | - Amy E. Herr
- Department of Bioengineering, University of California, Berkeley, CA 94720, USA
- The UC Berkeley—UCSF Graduate Program in Bioengineering, University of California, Berkeley, CA 94720, USA
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Taniguchi K, Sakai M, Sugito N, Kumazaki M, Shinohara H, Yamada N, Nakayama T, Ueda H, Nakagawa Y, Ito Y, Futamura M, Uno B, Otsuki Y, Yoshida K, Uchiyama K, Akao Y. PTBP1-associated microRNA-1 and -133b suppress the Warburg effect in colorectal tumors. Oncotarget 2017; 7:18940-52. [PMID: 26980745 PMCID: PMC4951342 DOI: 10.18632/oncotarget.8005] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 02/05/2016] [Indexed: 01/24/2023] Open
Abstract
It is known that pyruvate kinase in muscle (PKM), which is a rate-limiting glycolytic enzyme, has essential roles in the Warburg effect and that expression of cancer-dominant PKM2 is increased by polypyrimidine tract-binding protein 1 (PTBP1), which is a splicer of the PKM gene. In other words, PKM2 acts as a promoter of the Warburg effect. Previously, we demonstrated that the Warburg effect was partially established by down-regulation of several microRNAs (miRs) that bind to PTBP1 and that ectopic expression of these miRs suppressed the Warburg effect. In this study, we investigated the functions of miR-1 and -133b, which are well known as muscle-specific miRs, from the viewpoint of the Warburg effect in colorectal tumors. The expression levels of miR-1 and -133b were relatively high in colon tissue except muscle and very frequently down-regulated in 75 clinical colorectal tumors samples, even in adenomas, compared with those of the adjacent normal tissue samples. The ectopic expression of these miRs induced growth suppression and autophagic cell death through the switching of PKM isoform expression from PKM2 to PKM1 by silencing PTBP1 expression both in vitro and in vivo. Also, we showed that the resultant increase in the intracellular level of reactive oxygen species (ROS) was involved in this mechanism. Furthermore, PTBP1 was highly expressed in most of the 30 clinical colorectal tumor samples examined, even in adenomas. Our results suggested that PTBP1 and PTBP1-associated miR-1 and -133b are crucial molecules for the maintenance of the Warburg effect in colorectal tumors.
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Affiliation(s)
- Kohei Taniguchi
- United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Gifu 501-1193, Japan.,Department of General and Gastroenterological Surgery, Osaka Medical College, Takatsuki, Osaka 569-8686, Japan
| | - Miku Sakai
- United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Gifu 501-1193, Japan
| | - Nobuhiko Sugito
- United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Gifu 501-1193, Japan
| | - Minami Kumazaki
- United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Gifu 501-1193, Japan
| | - Haruka Shinohara
- United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Gifu 501-1193, Japan
| | - Nami Yamada
- United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Gifu 501-1193, Japan
| | - Tatsushi Nakayama
- United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Gifu 501-1193, Japan
| | - Hiroshi Ueda
- United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Gifu 501-1193, Japan
| | - Yoshihito Nakagawa
- Department of Gastroenterology, Fujita Health University, School of Medicine, Kutsukake-cho, Toyoake, Aichi 470-1192, Japan
| | - Yuko Ito
- Department of Anatomy and Cell Biology, Division of Life Sciences, Osaka Medical College, Takatsuki, Osaka 569-8686, Japan
| | - Manabu Futamura
- Department of Oncological Surgery, Gifu University School of Medicine, Gifu 501-1193, Japan
| | - Bunji Uno
- United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Gifu 501-1193, Japan
| | - Yoshinori Otsuki
- Department of Anatomy and Cell Biology, Division of Life Sciences, Osaka Medical College, Takatsuki, Osaka 569-8686, Japan
| | - Kazuhiro Yoshida
- Department of Oncological Surgery, Gifu University School of Medicine, Gifu 501-1193, Japan
| | - Kazuhisa Uchiyama
- Department of General and Gastroenterological Surgery, Osaka Medical College, Takatsuki, Osaka 569-8686, Japan
| | - Yukihiro Akao
- United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Gifu 501-1193, Japan
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Jiao H, Dong P, Yan L, Yang Z, Lv X, Li Q, Zong X, Fan J, Fu X, Liu X, Xiao R. TGF-β1 Induces Polypyrimidine Tract-Binding Protein to Alter Fibroblasts Proliferation and Fibronectin Deposition in Keloid. Sci Rep 2016; 6:38033. [PMID: 27897224 PMCID: PMC5126665 DOI: 10.1038/srep38033] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Accepted: 11/03/2016] [Indexed: 02/04/2023] Open
Abstract
Human dermal fibrotic disease keloid has been a clinical challenge because of its tumour-like growth and the lack of effective therapy. Dysregulated alternative splicing events have been demonstrated in tumours and fibrosis. In the current study, for the first time, it was demonstrated that the splicing regulator polypyrimidine tract-binding protein (PTB), which plays a pivotal role in tumour proliferation, invasion and metastasis, is overexpressed in keloid tissues and fibroblasts. Additionally, TGF-β1 upregulated the expressions of PTB and its upstream regulator, C-MYC, in keloid fibroblasts. Furthermore, we suppressed PTB using siRNA in keloid fibroblasts and in a keloid xenograft nude mouse model. PTB knockdown significantly slowed the proliferation of keloid fibroblasts and accelerated the regression of transplanted keloid tissues, which was accompanied by a shift in the alternative splicing of USP5 and RTN4. Moreover, when PTB was suppressed, there was a reduction in excessive deposition of FN1 and COL3A1 in transplanted keloid tissues. However, only FN1 was downregulated in keloid fibroblasts that were cultured in media supplemented with TGF-β1. Our study provides evidence for the role of PTB in keloid pathophysiology and offers a novel therapeutic target for keloids. Most importantly, the role TGF-β1 regulation of PTB may provide new insights into the mechanisms underlying inflammatory cytokine-induced fibrosis.
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Affiliation(s)
- Hu Jiao
- Research Center of Plastic Surgery Hospital, Chinese Academy of Medical Sciences &Peking Union Medical College, Beijing, P.R. China
| | - Ping Dong
- Research Center of Plastic Surgery Hospital, Chinese Academy of Medical Sciences &Peking Union Medical College, Beijing, P.R. China
| | - Li Yan
- Research Center of Plastic Surgery Hospital, Chinese Academy of Medical Sciences &Peking Union Medical College, Beijing, P.R. China
| | - Zhigang Yang
- Research Center of Plastic Surgery Hospital, Chinese Academy of Medical Sciences &Peking Union Medical College, Beijing, P.R. China
| | - Xiaoyan Lv
- Research Center of Plastic Surgery Hospital, Chinese Academy of Medical Sciences &Peking Union Medical College, Beijing, P.R. China
| | - Qiuchen Li
- Research Center of Plastic Surgery Hospital, Chinese Academy of Medical Sciences &Peking Union Medical College, Beijing, P.R. China
| | - Xianlei Zong
- Scar Plastic Department of Plastic Surgery Hospital, Chinese Academy of Medical Sciences &Peking Union Medical College, Beijing, P.R. China
| | - Jincai Fan
- Scar Plastic Department of Plastic Surgery Hospital, Chinese Academy of Medical Sciences &Peking Union Medical College, Beijing, P.R. China
| | - Xin Fu
- Research Center of Plastic Surgery Hospital, Chinese Academy of Medical Sciences &Peking Union Medical College, Beijing, P.R. China
| | - Xia Liu
- Research Center of Plastic Surgery Hospital, Chinese Academy of Medical Sciences &Peking Union Medical College, Beijing, P.R. China
| | - Ran Xiao
- Research Center of Plastic Surgery Hospital, Chinese Academy of Medical Sciences &Peking Union Medical College, Beijing, P.R. China
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The impact of RNA binding motif protein 4-regulated splicing cascade on the progression and metabolism of colorectal cancer cells. Oncotarget 2016; 6:38046-60. [PMID: 26506517 PMCID: PMC4741983 DOI: 10.18632/oncotarget.5710] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 10/06/2015] [Indexed: 01/17/2023] Open
Abstract
Dysregulated splicing of pre-messenger (m)RNA is considered a molecular occasion of carcinogenesis. However, the underlying mechanism is complex and remains to be investigated. Herein, we report that the upregulated miR-92a reduced the RNA-binding motif 4 (RBM4) protein expression, leading to the imbalanced expression of the neuronal polypyrimidine tract-binding (nPTB) protein through alternative splicing-coupled nonsense mediated decay (NMD) mechanism. Increase in nPTB protein enhances the relative level of fibroblast growth factor receptor 2 IIIc (FGFR2) and pyruvate kinase M2 (PKM2) transcripts which contribute to the progression and metabolic signature of CRC cells. Expression profiles of RBM4 and downstream alternative splicing events are consistently observed in cancerous tissues compared to adjacent normal tissues. These results constitute a mechanistic understanding of RBM4 on repressing the carcinogenesis of colorectal cells.
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Geuens T, Bouhy D, Timmerman V. The hnRNP family: insights into their role in health and disease. Hum Genet 2016; 135:851-67. [PMID: 27215579 PMCID: PMC4947485 DOI: 10.1007/s00439-016-1683-5] [Citation(s) in RCA: 673] [Impact Index Per Article: 84.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 05/09/2016] [Indexed: 12/14/2022]
Abstract
Heterogeneous nuclear ribonucleoproteins (hnRNPs) represent a large family of RNA-binding proteins (RBPs) that contribute to multiple aspects of nucleic acid metabolism including alternative splicing, mRNA stabilization, and transcriptional and translational regulation. Many hnRNPs share general features, but differ in domain composition and functional properties. This review will discuss the current knowledge about the different hnRNP family members, focusing on their structural and functional divergence. Additionally, we will highlight their involvement in neurodegenerative diseases and cancer, and the potential to develop RNA-based therapies.
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Affiliation(s)
- Thomas Geuens
- Peripheral Neuropathy Group, VIB Molecular Genetics Department, University of Antwerp-CDE, Parking P4, Building V, Room 1.30, Universiteitsplein 1, 2610, Antwerp, Belgium
- Neurogenetics Laboratory, Institute Born Bunge, University of Antwerp, Antwerp, Belgium
| | - Delphine Bouhy
- Peripheral Neuropathy Group, VIB Molecular Genetics Department, University of Antwerp-CDE, Parking P4, Building V, Room 1.30, Universiteitsplein 1, 2610, Antwerp, Belgium
- Neurogenetics Laboratory, Institute Born Bunge, University of Antwerp, Antwerp, Belgium
| | - Vincent Timmerman
- Peripheral Neuropathy Group, VIB Molecular Genetics Department, University of Antwerp-CDE, Parking P4, Building V, Room 1.30, Universiteitsplein 1, 2610, Antwerp, Belgium.
- Neurogenetics Laboratory, Institute Born Bunge, University of Antwerp, Antwerp, Belgium.
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36
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Even Y, Escande ML, Fayet C, Genevière AM. CDK13, a Kinase Involved in Pre-mRNA Splicing, Is a Component of the Perinucleolar Compartment. PLoS One 2016; 11:e0149184. [PMID: 26886422 PMCID: PMC4757566 DOI: 10.1371/journal.pone.0149184] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Accepted: 01/07/2016] [Indexed: 02/07/2023] Open
Abstract
The perinucleolar compartment (PNC) is a subnuclear stucture forming predominantly in cancer cells; its prevalence positively correlates with metastatic capacity. Although several RNA-binding proteins have been characterized in PNC, the molecular function of this compartment remains unclear. Here we demonstrate that the cyclin-dependent kinase 13 (CDK13) is a newly identified constituent of PNC. CDK13 is a kinase involved in the regulation of gene expression and whose overexpression was found to alter pre-mRNA processing. In this study we show that CDK13 is enriched in PNC and co-localizes all along the cell cycle with the PNC component PTB. In contrast, neither the cyclins K and L, known to associate with CDK13, nor the potential kinase substrates accumulate in PNC. We further show that CDK13 overexpression increases PNC prevalence suggesting that CDK13 may be determinant for PNC formation. This result linked to the finding that CDK13 gene is amplified in different types of cancer indicate that this kinase can contribute to cancer development in human.
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Affiliation(s)
- Yasmine Even
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, F-66650, Banyuls/Mer, France
| | - Marie-Line Escande
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, F-66650, Banyuls/Mer, France
| | - Claire Fayet
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, F-66650, Banyuls/Mer, France
| | - Anne-Marie Genevière
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, F-66650, Banyuls/Mer, France
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Tan LY, Whitfield P, Llorian M, Monzon-Casanova E, Diaz-Munoz MD, Turner M, Smith CWJ. Generation of functionally distinct isoforms of PTBP3 by alternative splicing and translation initiation. Nucleic Acids Res 2015; 43:5586-600. [PMID: 25940628 PMCID: PMC4477659 DOI: 10.1093/nar/gkv429] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 04/21/2015] [Indexed: 12/21/2022] Open
Abstract
Polypyrimidine tract binding protein (PTBP1) is a widely expressed RNA binding protein that acts as a regulator of alternative splicing and of cytoplasmic mRNA functions. Vertebrates contain two closely-related paralogs with >75% amino acid sequence identity. Early replacement of PTBP1 by PTBP2 during neuronal differentiation causes a concerted set of splicing changes. By comparison, very little is known about the molecular functions or physiological roles of PTBP3, although its expression and conservation throughout the vertebrates suggest a role in haematopoietic cells. To begin to understand its functions we have characterized the mRNA and protein isoform repertoire of PTBP3. Combinatorial alternative splicing events at the 5′ end of the gene allow for the generation of eight mRNA and three major protein isoforms. Individual mRNAs generate up to three protein isoforms via alternative translation initiation by re-initiation and leaky scanning using downstream AUG codons. The N-terminally truncated PTBP3 isoforms lack nuclear localization signals and/or most of the RRM1 domain and vary in their RNA binding properties and nuclear/cytoplasmic distribution, suggesting that PTBP3 may have major post-transcriptional cytoplasmic roles. Our findings set the stage for understanding the non-redundant physiological roles of PTBP3.
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Affiliation(s)
- Lit-Yeen Tan
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK
| | - Peter Whitfield
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK
| | - Miriam Llorian
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK
| | - Elisa Monzon-Casanova
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK Laboratory of Lymphocyte Signalling and Development, The Babraham Institute, Babraham Research Campus, CB22 3AT, UK
| | - Manuel D Diaz-Munoz
- Laboratory of Lymphocyte Signalling and Development, The Babraham Institute, Babraham Research Campus, CB22 3AT, UK
| | - Martin Turner
- Laboratory of Lymphocyte Signalling and Development, The Babraham Institute, Babraham Research Campus, CB22 3AT, UK
| | - Christopher W J Smith
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK
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Takahashi H, Nishimura J, Kagawa Y, Kano Y, Takahashi Y, Wu X, Hiraki M, Hamabe A, Konno M, Haraguchi N, Takemasa I, Mizushima T, Ishii M, Mimori K, Ishii H, Doki Y, Mori M, Yamamoto H. Significance of Polypyrimidine Tract–Binding Protein 1 Expression in Colorectal Cancer. Mol Cancer Ther 2015; 14:1705-16. [DOI: 10.1158/1535-7163.mct-14-0142] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Accepted: 04/12/2015] [Indexed: 11/16/2022]
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Yarosh CA, Iacona JR, Lutz CS, Lynch KW. PSF: nuclear busy-body or nuclear facilitator? WILEY INTERDISCIPLINARY REVIEWS-RNA 2015; 6:351-67. [PMID: 25832716 PMCID: PMC4478221 DOI: 10.1002/wrna.1280] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 02/28/2015] [Accepted: 03/02/2015] [Indexed: 01/25/2023]
Abstract
PTB-associated splicing factor (PSF) is an abundant and essential nucleic acid-binding protein that participates in a wide range of gene regulatory processes and cellular response pathways. At the protein level, PSF consists of multiple domains, many of which remain poorly characterized. Although grouped in a family with the proteins p54nrb/NONO and PSPC1 based on sequence homology, PSF contains additional protein sequence not included in other family members. Consistently, PSF has also been implicated in functions not ascribed to p54nrb/NONO or PSPC1. Here, we provide a review of the cellular activities in which PSF has been implicated and what is known regarding the mechanisms by which PSF functions in each case. We propose that the complex domain arrangement of PSF allows for its diversity of function and integration of activities. Finally, we discuss recent evidence that individual activities of PSF can be regulated independently from one another through the activity of domain-specific co-factors.
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Affiliation(s)
- Christopher A Yarosh
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA, USA
| | - Joseph R Iacona
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers Biomedical and Health Sciences-New Jersey Medical School, Newark, NJ, USA
| | - Carol S Lutz
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers Biomedical and Health Sciences-New Jersey Medical School, Newark, NJ, USA
| | - Kristen W Lynch
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA, USA
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Snijders AP, Hautbergue GM, Bloom A, Williamson JC, Minshull TC, Phillips HL, Mihaylov SR, Gjerde DT, Hornby DP, Wilson SA, Hurd PJ, Dickman MJ. Arginine methylation and citrullination of splicing factor proline- and glutamine-rich (SFPQ/PSF) regulates its association with mRNA. RNA (NEW YORK, N.Y.) 2015; 21:347-59. [PMID: 25605962 PMCID: PMC4338332 DOI: 10.1261/rna.045138.114] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 11/15/2014] [Indexed: 05/19/2023]
Abstract
Splicing factor proline- and glutamine-rich (SFPQ) also commonly known as polypyrimidine tract-binding protein-associated-splicing factor (PSF) and its binding partner non-POU domain-containing octamer-binding protein (NONO/p54nrb), are highly abundant, multifunctional nuclear proteins. However, the exact role of this complex is yet to be determined. Following purification of the endogeneous SFPQ/NONO complex, mass spectrometry analysis identified a wide range of interacting proteins, including those involved in RNA processing, RNA splicing, and transcriptional regulation, consistent with a multifunctional role for SFPQ/NONO. In addition, we have identified several sites of arginine methylation in SFPQ/PSF using mass spectrometry and found that several arginines in the N-terminal domain of SFPQ/PSF are asymmetrically dimethylated. Furthermore, we find that the protein arginine N-methyltransferase, PRMT1, catalyzes this methylation in vitro and that this is antagonized by citrullination of SFPQ. Arginine methylation and citrullination of SFPQ/PSF does not affect complex formation with NONO. However, arginine methylation was shown to increase the association with mRNA in mRNP complexes in mammalian cells. Finally we show that the biochemical properties of the endogenous complex from cell lysates are significantly influenced by the ionic strength during purification. At low ionic strength, the SFPQ/NONO complex forms large heterogeneous protein assemblies or aggregates, preventing the purification of the SFPQ/NONO complex. The ability of the SFPQ/NONO complex to form varying protein assemblies, in conjunction with the effect of post-translational modifications of SFPQ modulating mRNA binding, suggests key roles affecting mRNP dynamics within the cell.
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Affiliation(s)
- Ambrosius P Snijders
- ChELSI Institute, Chemical and Biological Engineering, University of Sheffield, Sheffield S1 3JD, United Kingdom
| | - Guillaume M Hautbergue
- Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield S10 2HQ, United Kingdom
| | - Alex Bloom
- Department of Molecular Biology and Biotechnology, Krebs Institute, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - James C Williamson
- ChELSI Institute, Chemical and Biological Engineering, University of Sheffield, Sheffield S1 3JD, United Kingdom
| | - Thomas C Minshull
- ChELSI Institute, Chemical and Biological Engineering, University of Sheffield, Sheffield S1 3JD, United Kingdom
| | - Helen L Phillips
- ChELSI Institute, Chemical and Biological Engineering, University of Sheffield, Sheffield S1 3JD, United Kingdom
| | - Simeon R Mihaylov
- Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield S10 2HQ, United Kingdom
| | | | - David P Hornby
- Department of Molecular Biology and Biotechnology, Krebs Institute, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Stuart A Wilson
- Department of Molecular Biology and Biotechnology, Krebs Institute, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Paul J Hurd
- School of Biological and Chemical Sciences, Queen Mary University of London, London E1 4NS, United Kingdom
| | - Mark J Dickman
- ChELSI Institute, Chemical and Biological Engineering, University of Sheffield, Sheffield S1 3JD, United Kingdom
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Long non-coding RNA MALAT1 promotes tumour growth and metastasis in colorectal cancer through binding to SFPQ and releasing oncogene PTBP2 from SFPQ/PTBP2 complex. Br J Cancer 2014; 111:736-48. [PMID: 25025966 PMCID: PMC4134507 DOI: 10.1038/bjc.2014.383] [Citation(s) in RCA: 298] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2014] [Revised: 06/10/2014] [Accepted: 06/17/2014] [Indexed: 12/16/2022] Open
Abstract
Background: Metastasis associated with lung adenocarcinoma transcript-1 (MALAT1) is a functional long non-coding RNA (lncRNA), which is highly expressed in several tumours, including colorectal cancer (CRC). Its biological function and mechanism in the prognosis of human CRC is still largely under investigation. Methods: This study aimed to investigate the new effect mechanism of MALAT1 on the proliferation and migration of CRC cells in vitro and in vivo, and detect the expression of MALAT1, SFPQ (also known as PSF (PTB-associated splicing factor)), and PTBP2 (also known as PTB (polypyrimidine-tract-binding protein)) in CRC tumour tissues, followed by correlated analysis with clinicopathological parameters. Results: We found that overexpression of MALAT1 could promote cell proliferation and migration in vitro, and promote tumour growth and metastasis in nude mice. The underlying mechanism was associated with tumour suppressor gene SFPQ and proto-oncogene PTBP2. In CRC, MALAT1 could bind to SFPQ, thus releasing PTBP2 from the SFPQ/PTBP2 complex. In turn, the increased SFPQ-detached PTBP2 promoted cell proliferation and migration. SFPQ critically mediated the regulatory effects of MALAT1. Moreover, in CRC tissues, MALAT1 and PTBP2 were overexpressed, both of which were associated closely with the invasion and metastasis of CRC. However, the SFPQ showed unchanged expression either in CRC tissues or adjacent normal tissues. Conclusions: Our findings implied that MALAT1 might be a potential predictor for tumour metastasis and prognosis. Furthermore, the interaction between MALAT1 and SFPQ could be a novel therapeutic target for CRC.
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Cho S, Moon H, Loh TJ, Oh HK, Williams DR, Liao DJ, Zhou J, Green MR, Zheng X, Shen H. PSF contacts exon 7 of SMN2 pre-mRNA to promote exon 7 inclusion. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1839:517-25. [PMID: 24632473 DOI: 10.1016/j.bbagrm.2014.03.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 12/07/2013] [Revised: 03/03/2014] [Accepted: 03/06/2014] [Indexed: 12/23/2022]
Abstract
Spinal muscular atrophy (SMA) is an autosomal recessive genetic disease and a leading cause of infant mortality. Deletions or mutations of SMN1 cause SMA, a gene that encodes a SMN protein. SMN is important for the assembly of Sm proteins onto UsnRNA to UsnRNP. SMN has also been suggested to direct axonal transport of β-actin mRNA in neurons. Humans contain a second SMN gene called SMN2 thus SMA patients produce some SMN but not with sufficient levels. The majority of SMN2 mRNA does not include exon 7. Here we show that increased expression of PSF promotes inclusion of exon 7 in the SMN2 whereas reduced expression of PSF promotes exon 7 skipping. In addition, we present evidence showing that PSF interacts with the GAAGGA enhancer in exon 7. We also demonstrate that a mutation in this enhancer abolishes the effects of PSF on exon 7 splicing. Furthermore we show that the RNA target sequences of PSF and tra2β in exon 7 are partially overlapped. These results lead us to conclude that PSF interacts with an enhancer in exon 7 to promote exon 7 splicing of SMN2 pre-mRNA.
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Affiliation(s)
- Sunghee Cho
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea
| | - Heegyum Moon
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea
| | - Tiing Jen Loh
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea
| | - Hyun Kyung Oh
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea
| | - Darren Reese Williams
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea
| | - D Joshua Liao
- Hormel Institute, University of Minnesota, Austin, MN, USA
| | | | - Michael R Green
- Howard Hughes Medical Institute and Programs in Gene Function and Expression and Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Xuexiu Zheng
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea
| | - Haihong Shen
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea.
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He X, Arslan AD, Ho TT, Yuan C, Stampfer MR, Beck WT. Involvement of polypyrimidine tract-binding protein (PTBP1) in maintaining breast cancer cell growth and malignant properties. Oncogenesis 2014; 3:e84. [PMID: 24418892 PMCID: PMC3940912 DOI: 10.1038/oncsis.2013.47] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 11/13/2013] [Accepted: 11/14/2013] [Indexed: 12/12/2022] Open
Abstract
We have investigated some roles of splicing factor polypyrimidine tract-binding protein (PTBP1) in human breast cancer. We found that PTBP1 was upregulated in progressively transformed human mammary epithelial cells (HMECs), as well as in breast tumor cell lines compared with HMECs with finite growth potential and found that the level of PTBP1 correlated with the transformation state of HMECs. Knockdown of PTBP1 expression substantially inhibited tumor cell growth, colony formation in soft agar and in vitro invasiveness of breast cancer cell lines, a result similar to what we have reported in ovarian cancer. However, ectopic expression of PTBP1 (as a PTBP1-EGFP fusion protein) did not enhance the proliferation of immortalized HMEC. Rather, PTBP1 expression promoted anchorage-independent growth of an immortalized HMEC as assessed by increased colony formation in soft agar. In addition, we found that knockdown of PTBP1 expression led to upregulation of the expression of the M1 isoform of pyruvate kinase (PKM1) and increase of the ratio of PKM1 vs PKM2. PKM1 has been reported to promote oxidative phosphorylation and reduce tumorigenesis. Correspondingly, we observed increased oxygen consumption in PTBP1-knockdown breast cancer cells. Together, these results suggest that PTBP1 is associated with breast tumorigenesis and appears to be required for tumor cell growth and maintenance of transformed properties. PTBP1 exerts these effects, in part, by regulating the splicing of pyruvate kinase, and consequently alters glucose metabolism and contributes to the Warburg effect.
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Affiliation(s)
- X He
- 1] Department of Biopharmaceutical Sciences, College of Pharmacy-Rockford, University of Illinois at Chicago, Rockford, IL, USA [2] Cancer Center, University of Illinois, Chicago, IL, USA
| | - A D Arslan
- Department of Biopharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
| | - T-T Ho
- Department of Biopharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
| | - C Yuan
- Department of Biopharmaceutical Sciences, College of Pharmacy-Rockford, University of Illinois at Chicago, Rockford, IL, USA
| | - M R Stampfer
- Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - W T Beck
- 1] Cancer Center, University of Illinois, Chicago, IL, USA [2] Department of Biopharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
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44
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Giudice J, Cooper TA. RNA-binding proteins in heart development. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 825:389-429. [PMID: 25201112 DOI: 10.1007/978-1-4939-1221-6_11] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
RNA-binding proteins (RBPs) are key players of posttranscriptional regulation occurring during normal tissue development. All tissues examined thus far have revealed the importance of RBPs in the regulation of complex networks involved in organ morphogenesis, maturation, and function. They are responsible for controlling tissue-specific gene expression by regulating alternative splicing, mRNA stability, translation, and poly-adenylation. The heart is the first organ form during embryonic development and is also the first to acquire functionality. Numerous remodeling processes take place during late cardiac development since fetal heart first adapts to birth and then undergoes a transition to adult functionality. This physiological remodeling involves transcriptional and posttranscriptional networks that are regulated by RBPs. Disruption of the normal regulatory networks has been shown to cause cardiomyopathy in humans and animal models. Here we review the complexity of late heart development and the current information regarding how RBPs control aspects of postnatal heart development. We also review how activities of RBPs are modulated adding complexity to the regulation of developmental networks.
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Affiliation(s)
- Jimena Giudice
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX, 77030, USA,
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45
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New insights into functional roles of the polypyrimidine tract-binding protein. Int J Mol Sci 2013; 14:22906-32. [PMID: 24264039 PMCID: PMC3856098 DOI: 10.3390/ijms141122906] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2013] [Revised: 11/13/2013] [Accepted: 11/13/2013] [Indexed: 12/20/2022] Open
Abstract
Polypyrimidine Tract Binding Protein (PTB) is an intensely studied RNA binding protein involved in several post-transcriptional regulatory events of gene expression. Initially described as a pre-mRNA splicing regulator, PTB is now widely accepted as a multifunctional protein shuttling between nucleus and cytoplasm. Accordingly, PTB can interact with selected RNA targets, structural elements and proteins. There is increasing evidence that PTB and its paralog PTBP2 play a major role as repressors of alternatively spliced exons, whose transcription is tissue-regulated. In addition to alternative splicing, PTB is involved in almost all steps of mRNA metabolism, including polyadenylation, mRNA stability and initiation of protein translation. Furthermore, it is well established that PTB recruitment in internal ribosome entry site (IRES) activates the translation of picornaviral and cellular proteins. Detailed studies of the structural properties of PTB have contributed to our understanding of the mechanism of RNA binding by RNA Recognition Motif (RRM) domains. In the present review, we will describe the structural properties of PTB, its paralogs and co-factors, the role in post-transcriptional regulation and actions in cell differentiation and pathogenesis. Defining the multifunctional roles of PTB will contribute to the understanding of key regulatory events in gene expression.
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46
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Jahan N, Wimmer E, Mueller S. Polypyrimidine tract binding protein-1 (PTB1) is a determinant of the tissue and host tropism of a human rhinovirus/poliovirus chimera PV1(RIPO). PLoS One 2013; 8:e60791. [PMID: 23593313 PMCID: PMC3617181 DOI: 10.1371/journal.pone.0060791] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Accepted: 03/03/2013] [Indexed: 01/08/2023] Open
Abstract
The internal ribosomal entry site (IRES) of picornavirus genomes serves as the nucleation site of a highly structured ribonucleoprotein complex essential to the binding of the 40S ribosomal subunit and initiation of viral protein translation. The transition from naked RNA to a functional "IRESome" complex are poorly understood, involving the folding of secondary and tertiary RNA structure, facilitated by a tightly concerted binding of various host cell proteins that are commonly referred to as IRES trans-acting factors (ITAFs). Here we have investigated the influence of one ITAF, the polypyrimidine tract-binding protein 1 (PTB1), on the tropism of PV1(RIPO), a chimeric poliovirus in which translation of the poliovirus polyprotein is under the control of a human rhinovirus type 2 (HRV2) IRES element. We show that PV1(RIPO)'s growth defect in restrictive mouse cells is partly due to the inability of its IRES to interact with endogenous murine PTB. Over-expression of human PTB1 stimulated the HRV2 IRES-mediated translation, resulting in increased growth of PV1(RIPO) in murine cells and human neuronal SK-N-MC cells. Mutations within the PV1(RIPO) IRES, selected to grow in restrictive mouse cells, eliminated the human PTB1 supplementation requirement, by restoring the ability of the IRES to interact with endogenous murine PTB. In combination with our previous findings these results give a compelling insight into the thermodynamic behavior of IRES structures. We have uncovered three distinct thermodynamic aspects of IRES formation which may independently contribute to overcome the observed PV1(RIPO) IRES block by lowering the free energy δG of the IRESome formation, and stabilizing the correct and functional structure: 1) lowering the growth temperature, 2) modifying the complement of ITAFs in restricted cells, or 3) selection of adaptive mutations. All three mechanisms can conceivably modulate the thermodynamics of RNA folding, and thus facilitate and stabilize the functional IRES structure.
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Affiliation(s)
- Nusrat Jahan
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, New York, United States of America
| | - Eckard Wimmer
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, New York, United States of America
| | - Steffen Mueller
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, New York, United States of America
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Ascano M, Gerstberger S, Tuschl T. Multi-disciplinary methods to define RNA-protein interactions and regulatory networks. Curr Opin Genet Dev 2013; 23:20-8. [PMID: 23453689 DOI: 10.1016/j.gde.2013.01.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Revised: 12/21/2012] [Accepted: 01/09/2013] [Indexed: 01/13/2023]
Abstract
The advent of high-throughput technologies including deep-sequencing and protein mass spectrometry is facilitating the acquisition of large and precise data sets toward the definition of post-transcriptional regulatory networks. While early studies that investigated specific RNA-protein interactions in isolation laid the foundation for our understanding of the existence of molecular machines to assemble and process RNAs, there is a more recent appreciation of the importance of individual RNA-protein interactions that contribute to post-transcriptional gene regulation. The multitude of RNA-binding proteins (RBPs) and their many RNA targets has only been captured experimentally in recent times. In this review, we will examine current multidisciplinary approaches toward elucidating RNA-protein networks and their regulation.
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Affiliation(s)
- Manuel Ascano
- Howard Hughes Medical Institute and Laboratory for RNA Molecular Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, United States
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48
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Abstract
PTB (polypyrimidine tract-binding protein) is an abundant and widely expressed RNA-binding protein with four RRM (RNA recognition motif) domains. PTB is involved in numerous post-transcriptional steps in gene expression in both the nucleus and cytoplasm, but has been best characterized as a regulatory repressor of some ASEs (alternative splicing events), and as an activator of translation driven by IRESs (internal ribosome entry segments). We have used a variety of approaches to characterize the activities of PTB and its molecular interactions with RNA substrates and protein partners. Using splice-sensitive microarrays we found that PTB acts not only as a splicing repressor but also as an activator, and that these two activities are determined by the location at which PTB binds relative to target exons. We have identified minimal splicing repressor and activator domains, and have determined high resolution structures of the second RRM domain of PTB binding to peptide motifs from the co-repressor protein Raver1. Using single-molecule techniques we have determined the stoichiometry of PTB binding to a regulated splicing substrate in whole nuclear extracts. Finally, we have used tethered hydroxyl radical probing to determine the locations on viral IRESs at which each of the four RRM domains bind. We are now combining tethered probing with single molecule analyses to gain a detailed understanding of how PTB interacts with pre-mRNA substrates to effect either repression or activation of splicing.
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Alternative splicing: functional diversity among voltage-gated calcium channels and behavioral consequences. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1828:1522-9. [PMID: 23022282 DOI: 10.1016/j.bbamem.2012.09.018] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Revised: 09/15/2012] [Accepted: 09/19/2012] [Indexed: 12/14/2022]
Abstract
Neuronal voltage-gated calcium channels generate rapid, transient intracellular calcium signals in response to membrane depolarization. Neuronal Ca(V) channels regulate a range of cellular functions and are implicated in a variety of neurological and psychiatric diseases including epilepsy, Parkinson's disease, chronic pain, schizophrenia, and bipolar disorder. Each mammalian Cacna1 gene has the potential to generate tens to thousands of Ca(V) channels by alternative pre-mRNA splicing, a process that adds fine granulation to the pool of Ca(V) channel structures and functions. The precise composition of Ca(V) channel splice isoform mRNAs expressed in each cell are controlled by cell-specific splicing factors. The activity of splicing factors are in turn regulated by molecules that encode various cellular features, including cell-type, activity, metabolic states, developmental state, and other factors. The cellular and behavioral consequences of individual sites of Ca(V) splice isoforms are being elucidated, as are the cell-specific splicing factors that control splice isoform selection. Altered patterns of alternative splicing of Ca(V) pre-mRNAs can alter behavior in subtle but measurable ways, with the potential to influence drug efficacy and disease severity. This article is part of a Special Issue entitled: Calcium channels.
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50
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Arslan AD, He X, Wang M, Rumschlag-Booms E, Rong L, Beck WT. A high-throughput assay to identify small-molecule modulators of alternative pre-mRNA splicing. ACTA ACUST UNITED AC 2012; 18:180-90. [PMID: 22972848 DOI: 10.1177/1087057112459901] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Alternative splicing (AS) is an efficient mechanism that involves the generation of transcriptome and protein diversity from a single gene. Defects in pre-messenger RNA (mRNA) splicing are an important cause of numerous diseases, including cancer. AS of pre-mRNA as a target for cancer therapy has not been well studied. We have reported previously that a splicing factor, polypyrimidine tract-binding protein (PTB), is overexpressed in ovarian tumors compared with matched normal controls, and knockdown of PTB expression by short-hairpin RNA impairs ovarian tumor cell growth, colony formation, and invasiveness. Given the complexity of PTB's molecular functions, a chemical method for controlling PTB activity might provide a therapeutic and experimental tool. However, no commercially available PTB inhibitors have yet been described. To expand our ability to find novel inhibitors, we developed a robust, fluorometric, cell-based high-throughput screening assay in 96-well plates that reports on the splicing activity of PTB. In an attempt to use the cells for large-scale chemical screens to identify PTB modulators, we established cell lines stably expressing the reporter gene. Our results suggest that this high-throughput assay could be used to identify small-molecule modulators of PTB activity. Based on these findings and the role that upregulated PTB has on cell proliferation and malignant properties of tumors, targeting PTB for inhibition with small molecules offers a promising strategy for cancer therapy.
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Affiliation(s)
- Ahmet Dirim Arslan
- Department of Biopharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
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