1
|
Basu J, Olsson A, Ferchen K, Titerina EK, Chetal K, Nicolas E, Czyzewicz P, Levchenko D, Ge L, Hua X, Grimes HL, Salomonis N, Kappes DJ. ThPOK is a critical multifaceted regulator of myeloid lineage development. Nat Immunol 2023; 24:1295-1307. [PMID: 37474652 PMCID: PMC10792516 DOI: 10.1038/s41590-023-01549-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 06/06/2023] [Indexed: 07/22/2023]
Abstract
The transcription factor ThPOK (encoded by Zbtb7b) is well known for its role as a master regulator of CD4 lineage commitment in the thymus. Here, we report an unexpected and critical role of ThPOK as a multifaceted regulator of myeloid lineage commitment, differentiation and maturation. Using reporter and knockout mouse models combined with single-cell RNA-sequencing, progenitor transfer and colony assays, we show that ThPOK controls monocyte-dendritic cell versus granulocyte lineage production during homeostatic differentiation, and serves as a brake for neutrophil maturation in granulocyte lineage-specified cells through transcriptional regulation of lineage-specific transcription factors and RNA via altered messenger RNA splicing to reprogram intron retention.
Collapse
Affiliation(s)
- Jayati Basu
- Fox Chase Cancer Center, Philadelphia, PA, USA.
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA.
| | - Andre Olsson
- Division of Immunobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
- Division of Biomedical Informatics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
- Department of Pediatrics, University of Cincinnati, Cincinnati, OH, USA
| | - Kyle Ferchen
- Division of Immunobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
- Division of Biomedical Informatics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Elizaveta K Titerina
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Kashish Chetal
- Department of Pediatrics, University of Cincinnati, Cincinnati, OH, USA
| | | | | | | | - Lu Ge
- Fox Chase Cancer Center, Philadelphia, PA, USA
| | - Xiang Hua
- Fox Chase Cancer Center, Philadelphia, PA, USA
| | - H Leighton Grimes
- Division of Immunobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
- Division of Biomedical Informatics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
- Department of Pediatrics, University of Cincinnati, Cincinnati, OH, USA
| | - Nathan Salomonis
- Division of Immunobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
- Division of Biomedical Informatics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
- Department of Pediatrics, University of Cincinnati, Cincinnati, OH, USA.
| | | |
Collapse
|
2
|
Siculella L, Giannotti L, Di Chiara Stanca B, Spedicato F, Calcagnile M, Quarta S, Massaro M, Damiano F. A comprehensive understanding of hnRNP A1 role in cancer: new perspectives on binding with noncoding RNA. Cancer Gene Ther 2023; 30:394-403. [PMID: 36460805 DOI: 10.1038/s41417-022-00571-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Revised: 11/23/2022] [Accepted: 11/23/2022] [Indexed: 12/03/2022]
Abstract
The heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) is the most abundant and ubiquitously expressed member of the heterogeneous nuclear ribonucleoproteins family (hnRNPs). hnRNP A1 is an RNA-binding protein associated with complexes active in diverse biological processes such as RNA splicing, transactivation of gene expression, and modulation of protein translation. It is overexpressed in several cancers, where it actively promotes the expression and translation of several key proteins and regulators associated with tumorigenesis and cancer progression. Interesting recent studies have focused on the RNA-binding property of hnRNP A1 and revealed previously under-explored functions of hnRNP A1 in the processing of miRNAs, and loading non-coding RNAs into exosomes. Here, we will report the recent advancements in our knowledge of the role of hnRNP A1 in the biological processes underlying cancer proliferation and growth, with a particular focus on metabolic reprogramming.
Collapse
Affiliation(s)
- Luisa Siculella
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Lecce, Italy
| | - Laura Giannotti
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Lecce, Italy
| | - Benedetta Di Chiara Stanca
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Lecce, Italy
| | - Francesco Spedicato
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Lecce, Italy
| | - Matteo Calcagnile
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Lecce, Italy
| | - Stefano Quarta
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Lecce, Italy
| | - Marika Massaro
- Institute of Clinical Physiology (IFC), National Research Council (CNR), Lecce, Italy
| | - Fabrizio Damiano
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Lecce, Italy.
| |
Collapse
|
3
|
Chowdhury MN, Jin H. The RGG motif proteins: Interactions, functions, and regulations. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1748. [PMID: 35661420 PMCID: PMC9718894 DOI: 10.1002/wrna.1748] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 04/25/2022] [Accepted: 05/09/2022] [Indexed: 01/31/2023]
Abstract
Proteins with motifs rich in arginines and glycines were discovered decades ago and are functionally involved in a staggering range of essential processes in the cell. Versatile, specific, yet adaptable molecular interactions enabled by the unique combination of arginine and glycine, combined with multiplicity of molecular recognition conferred by repeated di-, tri-, and multiple peptide motifs, allow RGG motif proteins to interact with a broad range of proteins and nucleic acids. Furthermore, posttranslational modifications at the arginines in the motif extend the RGG protein's capacity for a fine-tuned regulation. In this review, we focus on the biochemical properties of the RGG motif, its molecular interactions with RNAs and proteins, and roles of the posttranslational modification in modulating their interactions. We discuss current knowledge of the RGG motif proteins involved in mRNA transport and translation, highlight our merging understanding of their molecular functions in translational regulation and summarize areas of research in the future critical in understanding this important family of proteins. This article is categorized under: RNA Interactions with Proteins and Other Molecules > Protein-RNA Recognition RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications Translation > Mechanisms.
Collapse
Affiliation(s)
- Mashiat N. Chowdhury
- Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews Avenue, Urbana, IL 61801
| | - Hong Jin
- Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews Avenue, Urbana, IL 61801,Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, 600 S. Mathews Avenue, Urbana, IL 61801,Carl R. Woese Institute for Genomic Biology, 1206 West Gregory Drive, University of Illinois at Urbana-Champaign, 600 S. Mathews Avenue, Urbana, IL 61801,Corresponding author: Phone: (217)244-9493, Fax: (217)244-5858,
| |
Collapse
|
4
|
A CRISPR RNA-binding protein screen reveals regulators of RUNX1 isoform generation. Blood Adv 2021; 5:1310-1323. [PMID: 33656539 DOI: 10.1182/bloodadvances.2020002090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 01/19/2021] [Indexed: 11/20/2022] Open
Abstract
The proper balance of hematopoietic stem cell (HSC) self-renewal and differentiation is critical for normal hematopoiesis and is disrupted in hematologic malignancy. Among regulators of HSC fate, transcription factors have a well-defined central role, and mutations promote malignant transformation. More recently, studies have illuminated the importance of posttranscriptional regulation by RNA-binding proteins (RBPs) in hematopoiesis and leukemia development. However, the RBPs involved and the breadth of regulation are only beginning to be elucidated. Furthermore, the intersection between posttranscriptional regulation and hematopoietic transcription factor function is poorly understood. Here, we studied the posttranscriptional regulation of RUNX1, a key hematopoietic transcription factor. Alternative polyadenylation (APA) of RUNX1 produces functionally antagonistic protein isoforms (RUNX1a vs RUNX1b/c) that mediate HSC self-renewal vs differentiation, an RNA-processing event that is dysregulated in malignancy. Consequently, RBPs that regulate this event directly contribute to healthy and aberrant hematopoiesis. We modeled RUNX1 APA using a split GFP minigene reporter and confirmed the sensitivity of our model to detect changes in RNA processing. We used this reporter in a clustered regularly interspaced short palindromic repeats (CRISPR) screen consisting of single guide RNAs exclusively targeting RBPs and uncovered HNRNPA1 and KHDRBS1 as antagonistic regulators of RUNX1a isoform generation. Overall, our study provides mechanistic insight into the posttranscriptional regulation of a key hematopoietic transcription factor and identifies RBPs that may have widespread and important functions in hematopoiesis.
Collapse
|
5
|
Velázquez-Cruz A, Baños-Jaime B, Díaz-Quintana A, De la Rosa MA, Díaz-Moreno I. Post-translational Control of RNA-Binding Proteins and Disease-Related Dysregulation. Front Mol Biosci 2021; 8:658852. [PMID: 33987205 PMCID: PMC8111222 DOI: 10.3389/fmolb.2021.658852] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 03/22/2021] [Indexed: 12/20/2022] Open
Abstract
Cell signaling mechanisms modulate gene expression in response to internal and external stimuli. Cellular adaptation requires a precise and coordinated regulation of the transcription and translation processes. The post-transcriptional control of mRNA metabolism is mediated by the so-called RNA-binding proteins (RBPs), which assemble with specific transcripts forming messenger ribonucleoprotein particles of highly dynamic composition. RBPs constitute a class of trans-acting regulatory proteins with affinity for certain consensus elements present in mRNA molecules. However, these regulators are subjected to post-translational modifications (PTMs) that constantly adjust their activity to maintain cell homeostasis. PTMs can dramatically change the subcellular localization, the binding affinity for RNA and protein partners, and the turnover rate of RBPs. Moreover, the ability of many RBPs to undergo phase transition and/or their recruitment to previously formed membrane-less organelles, such as stress granules, is also regulated by specific PTMs. Interestingly, the dysregulation of PTMs in RBPs has been associated with the pathophysiology of many different diseases. Abnormal PTM patterns can lead to the distortion of the physiological role of RBPs due to mislocalization, loss or gain of function, and/or accelerated or disrupted degradation. This Mini Review offers a broad overview of the post-translational regulation of selected RBPs and the involvement of their dysregulation in neurodegenerative disorders, cancer and other pathologies.
Collapse
Affiliation(s)
- Alejandro Velázquez-Cruz
- Instituto de Investigaciones Químicas, Centro de Investigaciones Científicas Isla de la Cartuja, Universidad de Sevilla, Consejo Superior de Investigaciones Científicas, Seville, Spain
| | - Blanca Baños-Jaime
- Instituto de Investigaciones Químicas, Centro de Investigaciones Científicas Isla de la Cartuja, Universidad de Sevilla, Consejo Superior de Investigaciones Científicas, Seville, Spain
| | - Antonio Díaz-Quintana
- Instituto de Investigaciones Químicas, Centro de Investigaciones Científicas Isla de la Cartuja, Universidad de Sevilla, Consejo Superior de Investigaciones Científicas, Seville, Spain
| | - Miguel A De la Rosa
- Instituto de Investigaciones Químicas, Centro de Investigaciones Científicas Isla de la Cartuja, Universidad de Sevilla, Consejo Superior de Investigaciones Científicas, Seville, Spain
| | - Irene Díaz-Moreno
- Instituto de Investigaciones Químicas, Centro de Investigaciones Científicas Isla de la Cartuja, Universidad de Sevilla, Consejo Superior de Investigaciones Científicas, Seville, Spain
| |
Collapse
|
6
|
Multiple Sclerosis-Associated hnRNPA1 Mutations Alter hnRNPA1 Dynamics and Influence Stress Granule Formation. Int J Mol Sci 2021; 22:ijms22062909. [PMID: 33809384 PMCID: PMC7998649 DOI: 10.3390/ijms22062909] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 03/04/2021] [Accepted: 03/09/2021] [Indexed: 12/21/2022] Open
Abstract
Evidence indicates that dysfunctional heterogeneous ribonucleoprotein A1 (hnRNPA1; A1) contributes to the pathogenesis of neurodegeneration in multiple sclerosis. Understanding molecular mechanisms of neurodegeneration in multiple sclerosis may result in novel therapies that attenuate neurodegeneration, thereby improving the lives of MS patients with multiple sclerosis. Using an in vitro, blue light induced, optogenetic protein expression system containing the optogene Cryptochrome 2 and a fluorescent mCherry reporter, we examined the effects of multiple sclerosis-associated somatic A1 mutations (P275S and F281L) in A1 localization, cluster kinetics and stress granule formation in real-time. We show that A1 mutations caused cytoplasmic mislocalization, and significantly altered the kinetics of A1 cluster formation/dissociation, and the quantity and size of clusters. A1 mutations also caused stress granule formation to occur more quickly and frequently in response to blue light stimulation. This study establishes a live cell optogenetics imaging system to probe localization and association characteristics of A1. It also demonstrates that somatic mutations in A1 alter its function and promote stress granule formation, which supports the hypothesis that A1 dysfunction may exacerbate neurodegeneration in multiple sclerosis.
Collapse
|
7
|
Möller K, Wecker AL, Höflmayer D, Fraune C, Makrypidi-Fraune G, Hube-Magg C, Kluth M, Steurer S, Clauditz TS, Wilczak W, Simon R, Sauter G, Huland H, Heinzer H, Haese A, Schlomm T, Weidemann S, Luebke AM, Minner S, Bernreuther C, Bonk S, Marx A. Upregulation of the heterogeneous nuclear ribonucleoprotein hnRNPA1 is an independent predictor of early biochemical recurrence in TMPRSS2:ERG fusion-negative prostate cancers. Virchows Arch 2020; 477:625-636. [PMID: 32417965 PMCID: PMC7581599 DOI: 10.1007/s00428-020-02834-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 04/20/2020] [Accepted: 04/28/2020] [Indexed: 11/25/2022]
Abstract
Heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1) is a ubiquitous RNA splicing factor that is overexpressed and prognostically relevant in various human cancer types. To study the impact of hnRNPA1 expression in prostate cancer, we analyzed a tissue microarray containing 17,747 clinical prostate cancer specimens by immunohistochemistry. hnRNPA1 was expressed in normal prostate glandular cells but often overexpressed in cancer cells. hnRNPA1 immunostaining was interpretable in 14,258 cancers and considered strong in 33.4%, moderate in 45.9%, weak in 15.3%, and negative in 5.4%. Moderate to strong hnRNPA1 immunostaining was strongly linked to adverse tumor features including high classical and quantitative Gleason score, lymph node metastasis, advanced tumor stage, positive surgical margin, and early biochemical recurrence (p < 0.0001 each). The prognostic impact of hnRNPA1 immunostaining was independent of established preoperatively or postoperatively available prognostic parameters (p < 0.0001). Subset analyses revealed that all these associations were strongly driven by the fraction of cancers lacking the TMPRSS2:ERG gene fusion. Comparison with other key molecular data that were earlier obtained on the same TMA showed that hnRNPA1 overexpression was linked to high levels of androgen receptor (AR) expression (p < 0.0001) as well as presence of 9 of 11 chromosomal deletions (p < 0.05 each). A strong association between hnRNPA1 upregulation and tumor cell proliferation that was independent from the Gleason score supports a role for tumor cell aggressiveness. In conclusion, hnRNPA1 overexpression is an independent predictor of poor prognosis in ERG-negative prostate cancer. hnRNPA1 measurement, either alone or in combination, might provide prognostic information in ERG-negative prostate cancer.
Collapse
Affiliation(s)
- Katharina Möller
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Anna Lena Wecker
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Doris Höflmayer
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Christoph Fraune
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Georgia Makrypidi-Fraune
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Claudia Hube-Magg
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Martina Kluth
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Stefan Steurer
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Till S Clauditz
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Waldemar Wilczak
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Ronald Simon
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany.
| | - Guido Sauter
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Hartwig Huland
- Martini-Clinic, Prostate Cancer Center, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Hans Heinzer
- Martini-Clinic, Prostate Cancer Center, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Alexander Haese
- Martini-Clinic, Prostate Cancer Center, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Thorsten Schlomm
- Department of Urology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Sören Weidemann
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Andreas M Luebke
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Sarah Minner
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Christian Bernreuther
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Sarah Bonk
- General, Visceral and Thoracic Surgery Department and Clinic, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Andreas Marx
- Institute of Pathology, Klinikum Fürth, Fürth, Germany
| |
Collapse
|
8
|
Li SQ, Liu J, Zhang J, Wang XL, Chen D, Wang Y, Xu YM, Huang B, Lin J, Li J, Wang XZ. Transcriptome profiling reveals the high incidence of hnRNPA1 exon 8 inclusion in chronic myeloid leukemia. J Adv Res 2020; 24:301-310. [PMID: 32405436 PMCID: PMC7210475 DOI: 10.1016/j.jare.2020.04.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 03/08/2020] [Accepted: 04/25/2020] [Indexed: 01/30/2023] Open
Abstract
Chronic myeloid leukemia (CML) is a malignancy that evolves through a multi-step process. Alternative splicing of several genes has been linked to the progression of the disease, but involvement of alternations in splicing profiles has not been reported. RNA-seq of peripheral blood mononuclear cell (PBMC) samples characterized the differentially expressed and spliced transcripts in five CML chronic phase (CP) and five blast phase (BP) patients, and five healthy controls. Global splicing alteration analysis detected 6474 altered splicing events altered between CML and healthy samples, including many of the previously reported splicing variants and showing a more profound altered splicing deregulation in BP samples. Functional clustering of differentially spliced genes in CP revealed a preferred enrichment relating to cell signaling, while the spliceosome pathway was most overrepresented in BP samples. One differentially spliced spliceosome gene hnRNPA1 showed two splice isoforms; the longer isoform contained exon 8 was preferentially expressed in the BP patients, and the short one excluding exon 8 was specific to healthy controls. Our findings suggested that alternative splicing deregulation played a central role during the progression of CML from CP to BP, and the longer isoform of hnRNPA1 might represent a diagnostic marker and therapeutic target for CML.
Collapse
Affiliation(s)
- Shu-Qi Li
- Jiangxi Province Key Laboratory of Laboratory Medicine, Department of Clinical Laboratory, The Second Affiliated Hospital of Nanchang University, No.1 Min De Road, Nanchang 330006, China
| | - Jing Liu
- Jiangxi Province Key Laboratory of Laboratory Medicine, Department of Clinical Laboratory, The Second Affiliated Hospital of Nanchang University, No.1 Min De Road, Nanchang 330006, China
| | - Jing Zhang
- Jiangxi Province Key Laboratory of Laboratory Medicine, Department of Clinical Laboratory, The Second Affiliated Hospital of Nanchang University, No.1 Min De Road, Nanchang 330006, China
| | - Xue-Lian Wang
- Center for Genome Analysis, ABLife Inc., Wuhan 430075, China
| | - Dong Chen
- Center for Genome Analysis, ABLife Inc., Wuhan 430075, China
| | - Yan Wang
- Jiangxi Province Key Laboratory of Laboratory Medicine, Department of Clinical Laboratory, The Second Affiliated Hospital of Nanchang University, No.1 Min De Road, Nanchang 330006, China
| | - Yan-Mei Xu
- Jiangxi Province Key Laboratory of Laboratory Medicine, Department of Clinical Laboratory, The Second Affiliated Hospital of Nanchang University, No.1 Min De Road, Nanchang 330006, China
| | - Bo Huang
- Jiangxi Province Key Laboratory of Laboratory Medicine, Department of Clinical Laboratory, The Second Affiliated Hospital of Nanchang University, No.1 Min De Road, Nanchang 330006, China
| | - Jin Lin
- Jiangxi Province Key Laboratory of Laboratory Medicine, Department of Clinical Laboratory, The Second Affiliated Hospital of Nanchang University, No.1 Min De Road, Nanchang 330006, China
| | - Jing Li
- Department of Clinical Laboratory, The First Affiliated Hospital of Nanchang University, No.17 Yong Wai Road, Nanchang 330006, China
| | - Xiao-Zhong Wang
- Jiangxi Province Key Laboratory of Laboratory Medicine, Department of Clinical Laboratory, The Second Affiliated Hospital of Nanchang University, No.1 Min De Road, Nanchang 330006, China
- Corresponding author.
| |
Collapse
|
9
|
SRSF1 mediates cytokine-induced impaired imatinib sensitivity in chronic myeloid leukemia. Leukemia 2020; 34:1787-1798. [PMID: 32051529 DOI: 10.1038/s41375-020-0732-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Revised: 12/10/2019] [Accepted: 01/29/2020] [Indexed: 12/11/2022]
Abstract
Patients with chronic myeloid leukemia (CML) who are treated with tyrosine kinase inhibitors (TKIs) experience significant heterogeneity regarding depth and speed of responses. Factors intrinsic and extrinsic to CML cells contribute to response heterogeneity and TKI resistance. Among extrinsic factors, cytokine-mediated TKI resistance has been demonstrated in CML progenitors, but the underlying mechanisms remain obscure. Using RNA-sequencing, we identified differentially expressed splicing factors in primary CD34+ chronic phase (CP) CML progenitors and controls. We found SRSF1 expression to be increased as a result of both BCR-ABL1- and cytokine-mediated signaling. SRSF1 overexpression conferred cytokine independence to untransformed hematopoietic cells and impaired imatinib sensitivity in CML cells, while SRSF1 depletion in CD34+ CP CML cells prevented the ability of extrinsic cytokines to decrease imatinib sensitivity. Mechanistically, PRKCH and PLCH1 were upregulated by elevated SRSF1 levels, and contributed to impaired imatinib sensitivity. Importantly, very high SRSF1 levels in the bone marrow of CML patients at presentation correlated with poorer clinical TKI responses. In summary, we find SRSF1 levels to be maintained in CD34+ CP CML progenitors by cytokines despite effective BCR-ABL1 inhibition, and that elevated levels promote impaired imatinib responses. Together, our data support an SRSF1/PRKCH/PLCH1 axis in contributing to cytokine-induced impaired imatinib sensitivity in CML.
Collapse
|
10
|
Histone lysine demethylase KDM5B maintains chronic myeloid leukemia via multiple epigenetic actions. Exp Hematol 2020; 82:53-65. [PMID: 32007477 DOI: 10.1016/j.exphem.2020.01.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 01/17/2020] [Accepted: 01/18/2020] [Indexed: 11/23/2022]
Abstract
The histone lysine demethylase KDM5 family is implicated in normal development and stem cell maintenance by epigenetic modulation of histone methylation status. Deregulation of the KDM5 family has been reported in various types of cancers, including hematological malignancies. However, their transcriptional regulatory roles in the context of leukemia remain unclear. Here, we find that KDM5B is strongly expressed in normal CD34+ hematopoietic stem/progenitor cells and chronic myeloid leukemia (CML) cells. Knockdown of KDM5B in K562 CML cells reduced leukemia colony-forming potential. Transcriptome profiling of KDM5B knockdown K562 cells revealed the deregulation of genes involved in myeloid differentiation and Toll-like receptor signaling. Through the integration of transcriptome and ChIP-seq profiling data, we show that KDM5B is enriched at the binding sites of the GATA and AP-1 transcription factor families, suggesting their collaborations in the regulation of transcription. Even though the binding of KDM5B substantially overlapped with H3K4me1 or H3K4me3 mark at gene promoters, only a small subset of the KDM5B targets showed differential expression in association with the histone demethylation activity. By characterizing the interacting proteins in K562 cells, we discovered that KDM5B recruits protein complexes involved in the mRNA processing machinery, implying an alternative epigenetic action mediated by KDM5B in gene regulation. Our study highlights the oncogenic functions of KDM5B in CML cells and suggests that KDM5B is vital to the transcriptional regulation via multiple epigenetic mechanisms.
Collapse
|
11
|
Carrà G, Russo I, Guerrasio A, Morotti A. Nuclear-cytoplasmic Shuttling in Chronic Myeloid Leukemia: Implications in Leukemia Maintenance and Therapy. Cells 2019; 8:E1248. [PMID: 31614958 PMCID: PMC6830087 DOI: 10.3390/cells8101248] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 10/10/2019] [Accepted: 10/11/2019] [Indexed: 01/09/2023] Open
Abstract
Nuclear-cytoplasmic shuttling is a highly regulated and complex process, which involves both proteins and nucleic acids. Changes in cellular compartmentalization of various proteins, including oncogenes and tumor suppressors, affect cellular behavior, promoting or inhibiting proliferation, apoptosis and sensitivity to therapies. In this review, we will recapitulate the role of various shuttling components in Chronic Myeloid Leukemia and we will provide insights on the potential role of shuttling proteins as therapeutic targets.
Collapse
Affiliation(s)
- Giovanna Carrà
- Department of Clinical and Biological Sciences, University of Turin, Regione Gonzole 10, 10043 Orbassano (Turin), Italy.
| | - Isabella Russo
- Department of Clinical and Biological Sciences, University of Turin, Regione Gonzole 10, 10043 Orbassano (Turin), Italy.
| | - Angelo Guerrasio
- Department of Clinical and Biological Sciences, University of Turin, Regione Gonzole 10, 10043 Orbassano (Turin), Italy.
| | - Alessandro Morotti
- Department of Clinical and Biological Sciences, University of Turin, Regione Gonzole 10, 10043 Orbassano (Turin), Italy.
| |
Collapse
|
12
|
Gao X, Wan Z, Wei M, Dong Y, Zhao Y, Chen X, Li Z, Qin W, Yang G, Liu L. Chronic myelogenous leukemia cells remodel the bone marrow niche via exosome-mediated transfer of miR-320. Am J Cancer Res 2019; 9:5642-5656. [PMID: 31534508 PMCID: PMC6735391 DOI: 10.7150/thno.34813] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 07/07/2019] [Indexed: 12/20/2022] Open
Abstract
Rationale: Reciprocal interactions between leukemic cells and bone marrow mesenchymal stromal cells (BMMSC) remodel the normal niche into a malignant niche, leading to leukemia progression. Exosomes have emerged as an essential mediator of cell-cell communication. Whether leukemic exosomes involved in bone marrow niche remodeling remains unknown. Methods: We investigated the role of leukemic exosomes in molecular and functional changes of BMMSC in vitro and in vivo. RNA sequencing and bioinformatics were employed to screen for miRNAs that are selectively sorted into leukemic exosomes and the corresponding RNA binding proteins. Results: We demonstrated that leukemia cells significantly inhibited osteogenesis by BMMSC both in vivo and in vitro. Some tumor suppressive miRNAs, especially miR-320, were enriched in exosomes and thus secreted by leukemic cells, resulting in increased proliferation of the donor cells. In turn, the secreted exosomes were significantly endocytosed by adjacent BMMSC and thus inhibited osteogenesis at least partially via β-catenin inhibition. Mechanistically, miR-320 and some other miRNAs were sorted out into the exosomes by RNA binding protein heterogeneous nuclear ribonucleoprotein A1 (HNRNPA1), as these miRNAs harbor the recognition site for HNRNPA1. Conclusion: HNRNPA1-mediated exosomal transfer of miR-320 from leukemia cells to BMMSC is an important mediator of leukemia progression and is a potential therapeutic target for CML.
Collapse
|
13
|
Ji E, Lee H, Ahn S, Jung M, Lee SH, Lee JH, Lee EK. Heterogeneous nuclear ribonucleoprotein A1 promotes the expression of autophagy-related protein 6 in human colorectal cancer. Biochem Biophys Res Commun 2019; 513:255-260. [DOI: 10.1016/j.bbrc.2019.03.179] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 03/26/2019] [Indexed: 01/28/2023]
|
14
|
Li L, Yang X, Li K, Zhang G, Ma Y, Cai B, Li S, Ding H, Deng J, Nan X, Sun J, Wu Y, Shao N, Zhang L, Yang Z. d-/l-Isothymidine incorporation in the core sequence of aptamer BC15 enhanced its binding affinity to the hnRNP A1 protein. Org Biomol Chem 2019; 16:7488-7497. [PMID: 30272759 DOI: 10.1039/c8ob01454j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) was reported to participate in the development of a variety of tumors. BC15 is a DNA aptamer targeting hnRNP A1. Firstly, through sequence truncation, we identified 31-mer sequence BC15-31 as the core sequence of BC15 with a strong binding affinity and high selectivity to the hnRNP A1 protein. Isothymidine (isoT) modification was then applied for the structural optimization of BC15-31, systematic modification and biological evaluation were carried out. Incorporation of isoT in the 1,3 sites at the 5'-end of BC15-31 can significantly enhance the protein affinity. Chemical modifications close to the 3'-end can greatly improve the stability of the aptamer. Furthermore, BC15-31 modified with isoT at both the 5'-end and 3'-end displayed an additive effect with enhanced bioactivity and stability at the same time. Our study strategy on BC15 provides a useful guideline for chemical modification and optimization of the aptamer for further clinical application.
Collapse
Affiliation(s)
- Liyu Li
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191, China.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Computer-Aided Discovery of Small Molecules Targeting the RNA Splicing Activity of hnRNP A1 in Castration-Resistant Prostate Cancer. Molecules 2019; 24:molecules24040763. [PMID: 30791548 PMCID: PMC6413181 DOI: 10.3390/molecules24040763] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2019] [Revised: 02/08/2019] [Accepted: 02/16/2019] [Indexed: 12/28/2022] Open
Abstract
The heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) is a versatile RNA-binding protein playing a critical role in alternative pre-mRNA splicing regulation in cancer. Emerging data have implicated hnRNP A1 as a central player in a splicing regulatory circuit involving its direct transcriptional control by c-Myc oncoprotein and the production of the constitutively active ligand-independent alternative splice variant of androgen receptor, AR-V7, which promotes castration-resistant prostate cancer (CRPC). As there is an urgent need for effective CRPC drugs, targeting hnRNP A1 could, therefore, serve a dual purpose of preventing AR-V7 generation as well as reducing c-Myc transcriptional output. Herein, we report compound VPC-80051 as the first small molecule inhibitor of hnRNP A1 splicing activity discovered to date by using a computer-aided drug discovery approach. The inhibitor was developed to target the RNA-binding domain (RBD) of hnRNP A1. Further experimental evaluation demonstrated that VPC-80051 interacts directly with hnRNP A1 RBD and reduces AR-V7 messenger levels in 22Rv1 CRPC cell line. This study lays the groundwork for future structure-based development of more potent and selective small molecule inhibitors of hnRNP A1–RNA interactions aimed at altering the production of cancer-specific alternative splice isoforms.
Collapse
|
16
|
Neumann A, Schindler M, Olofsson D, Wilhelmi I, Schürmann A, Heyd F. Genome-wide identification of alternative splicing events that regulate protein transport across the secretory pathway. J Cell Sci 2019; 132:jcs.230201. [DOI: 10.1242/jcs.230201] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 03/09/2019] [Indexed: 01/05/2023] Open
Abstract
Alternative splicing (AS) strongly increases proteome diversity and functionality in eukaryotic cells. Protein secretion is a tightly-controlled process, especially in a tissue-specific and differentiation-dependent manner. While previous work has focussed on transcriptional and post-translational regulatory mechanisms, the impact of AS on the secretory pathway remains largely unexplored. Here we integrate a published screen for modulators of protein transport and RNA-Seq analyses to identify over 200 AS events as secretion regulators. We confirm that splicing events along all stages of the secretory pathway regulate the efficiency of membrane trafficking using Morpholinos and CRISPR/Cas9. We furthermore show that these events are highly tissue-specific and adapt the secretory pathway during T-cell activation and adipocyte differentiation. Our data substantially advance the understanding of AS functionality, add a new regulatory layer to a fundamental cell biological process and provide a resource of alternative isoforms that control the secretory pathway.
Collapse
Affiliation(s)
- Alexander Neumann
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Laboratory of RNA Biochemistry, Takustrasse 6, 14195 Berlin, Germany
| | - Magdalena Schindler
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Laboratory of RNA Biochemistry, Takustrasse 6, 14195 Berlin, Germany
| | - Didrik Olofsson
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Laboratory of RNA Biochemistry, Takustrasse 6, 14195 Berlin, Germany
| | - Ilka Wilhelmi
- Department of Experimental Diabetology, German Institute of Human Nutrition Potsdam-Rehbrücke (DIfE), 14558 Nuthetal, Germany
| | - Annette Schürmann
- Department of Experimental Diabetology, German Institute of Human Nutrition Potsdam-Rehbrücke (DIfE), 14558 Nuthetal, Germany
| | - Florian Heyd
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Laboratory of RNA Biochemistry, Takustrasse 6, 14195 Berlin, Germany
| |
Collapse
|
17
|
Díaz-Muñoz MD, Turner M. Uncovering the Role of RNA-Binding Proteins in Gene Expression in the Immune System. Front Immunol 2018; 9:1094. [PMID: 29875770 PMCID: PMC5974052 DOI: 10.3389/fimmu.2018.01094] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 05/02/2018] [Indexed: 12/29/2022] Open
Abstract
Fighting external pathogens requires an ever-changing immune system that relies on tight regulation of gene expression. Transcriptional control is the first step to build efficient responses while preventing immunodeficiencies and autoimmunity. Post-transcriptional regulation of RNA editing, location, stability, and translation are the other key steps for final gene expression, and they are all controlled by RNA-binding proteins (RBPs). Nowadays we have a deep understanding of how transcription factors control the immune system but recent evidences suggest that post-transcriptional regulation by RBPs is equally important for both development and activation of immune responses. Here, we review current knowledge about how post-transcriptional control by RBPs shapes our immune system and discuss the perspective of RBPs being the key players of a hidden immune cell epitranscriptome.
Collapse
Affiliation(s)
- Manuel D Díaz-Muñoz
- Centre de Physiopathologie Toulouse-Purpan, INSERM UMR1043/CNRS U5282, Toulouse, France
| | - Martin Turner
- Laboratory of Lymphocyte Signalling and Development, The Babraham Institute, Cambridge, United Kingdom
| |
Collapse
|
18
|
Post-Transcriptional Regulation of Anti-Apoptotic BCL2 Family Members. Int J Mol Sci 2018; 19:ijms19010308. [PMID: 29361709 PMCID: PMC5796252 DOI: 10.3390/ijms19010308] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 01/05/2018] [Accepted: 01/16/2018] [Indexed: 12/20/2022] Open
Abstract
Anti-apoptotic B cell lymphoma 2 (BCL2) family members (BCL2, MCL1, BCLxL, BCLW, and BFL1) are key players in the regulation of intrinsic apoptosis. Dysregulation of these proteins not only impairs normal development, but also contributes to tumor progression and resistance to various anti-cancer therapies. Therefore, cells maintain strict control over the expression of anti-apoptotic BCL2 family members using multiple mechanisms. Over the past two decades, the importance of post-transcriptional regulation of mRNA in controlling gene expression and its impact on normal homeostasis and disease have begun to be appreciated. In this review, we discuss the RNA binding proteins (RBPs) and microRNAs (miRNAs) that mediate post-transcriptional regulation of the anti-apoptotic BCL2 family members. We describe their roles and impact on alternative splicing, mRNA turnover, and mRNA subcellular localization. We also point out the importance of future studies in characterizing the crosstalk between RBPs and miRNAs in regulating anti-apoptotic BCL2 family member expression and ultimately apoptosis.
Collapse
|
19
|
Roy R, Huang Y, Seckl MJ, Pardo OE. Emerging roles of hnRNPA1 in modulating malignant transformation. WILEY INTERDISCIPLINARY REVIEWS-RNA 2017; 8. [PMID: 28791797 DOI: 10.1002/wrna.1431] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 05/19/2017] [Accepted: 05/22/2017] [Indexed: 01/05/2023]
Abstract
Heterogeneous nuclear ribonucleoproteins (hnRNPs) are RNA-binding proteins associated with complex and diverse biological processes such as processing of heterogeneous nuclear RNAs (hnRNAs) into mature mRNAs, RNA splicing, transactivation of gene expression, and modulation of protein translation. hnRNPA1 is the most abundant and ubiquitously expressed member of this protein family and has been shown to be involved in multiple molecular events driving malignant transformation. In addition to selective mRNA splicing events promoting expression of specific protein variants, hnRNPA1 regulates the gene expression and translation of several key players associated with tumorigenesis and cancer progression. Here, we will summarize our current knowledge of the involvement of hnRNPA1 in cancer, including its roles in regulating cell proliferation, invasiveness, metabolism, adaptation to stress and immortalization. WIREs RNA 2017, 8:e1431. doi: 10.1002/wrna.1431 For further resources related to this article, please visit the WIREs website.
Collapse
Affiliation(s)
- Rajat Roy
- Division of Cancer, Department of Surgery and Cancer, Imperial College London, London, UK
| | - Yueyang Huang
- Division of Cancer, Department of Surgery and Cancer, Imperial College London, London, UK
| | - Michael J Seckl
- Division of Cancer, Department of Surgery and Cancer, Imperial College London, London, UK
| | - Olivier E Pardo
- Division of Cancer, Department of Surgery and Cancer, Imperial College London, London, UK
| |
Collapse
|
20
|
Budak G, Srivastava R, Janga SC. Seten: a tool for systematic identification and comparison of processes, phenotypes, and diseases associated with RNA-binding proteins from condition-specific CLIP-seq profiles. RNA (NEW YORK, N.Y.) 2017; 23:836-846. [PMID: 28336542 PMCID: PMC5435856 DOI: 10.1261/rna.059089.116] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 03/21/2017] [Indexed: 06/06/2023]
Abstract
RNA-binding proteins (RBPs) control the regulation of gene expression in eukaryotic genomes at post-transcriptional level by binding to their cognate RNAs. Although several variants of CLIP (crosslinking and immunoprecipitation) protocols are currently available to study the global protein-RNA interaction landscape at single-nucleotide resolution in a cell, currently there are very few tools that can facilitate understanding and dissecting the functional associations of RBPs from the resulting binding maps. Here, we present Seten, a web-based and command line tool, which can identify and compare processes, phenotypes, and diseases associated with RBPs from condition-specific CLIP-seq profiles. Seten uses BED files resulting from most peak calling algorithms, which include scores reflecting the extent of binding of an RBP on the target transcript, to provide both traditional functional enrichment as well as gene set enrichment results for a number of gene set collections including BioCarta, KEGG, Reactome, Gene Ontology (GO), Human Phenotype Ontology (HPO), and MalaCards Disease Ontology for several organisms including fruit fly, human, mouse, rat, worm, and yeast. It also provides an option to dynamically compare the associated gene sets across data sets as bubble charts, to facilitate comparative analysis. Benchmarking of Seten using eCLIP data for IGF2BP1, SRSF7, and PTBP1 against their corresponding CRISPR RNA-seq in K562 cells as well as randomized negative controls, demonstrated that its gene set enrichment method outperforms functional enrichment, with scores significantly contributing to the discovery of true annotations. Comparative performance analysis using these CRISPR control data sets revealed significantly higher precision and comparable recall to that observed using ChIP-Enrich. Seten's web interface currently provides precomputed results for about 200 CLIP-seq data sets and both command line as well as web interfaces can be used to analyze CLIP-seq data sets. We highlight several examples to show the utility of Seten for rapid profiling of various CLIP-seq data sets. Seten is available on http://www.iupui.edu/∼sysbio/seten/.
Collapse
Affiliation(s)
- Gungor Budak
- Department of Biohealth Informatics, School of Informatics and Computing, Indiana University Purdue University Indianapolis (IUPUI), Indianapolis, Indiana 46202, USA
| | - Rajneesh Srivastava
- Department of Biohealth Informatics, School of Informatics and Computing, Indiana University Purdue University Indianapolis (IUPUI), Indianapolis, Indiana 46202, USA
| | - Sarath Chandra Janga
- Department of Biohealth Informatics, School of Informatics and Computing, Indiana University Purdue University Indianapolis (IUPUI), Indianapolis, Indiana 46202, USA
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA
| |
Collapse
|
21
|
Kędzierska H, Piekiełko-Witkowska A. Splicing factors of SR and hnRNP families as regulators of apoptosis in cancer. Cancer Lett 2017; 396:53-65. [PMID: 28315432 DOI: 10.1016/j.canlet.2017.03.013] [Citation(s) in RCA: 143] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 03/08/2017] [Accepted: 03/08/2017] [Indexed: 12/19/2022]
Abstract
SR and hnRNP proteins were initially discovered as regulators of alternative splicing: the process of controlled removal of introns and selective joining of exons through which multiple transcripts and, subsequently, proteins can be expressed from a single gene. Alternative splicing affects genes involved in all crucial cellular processes, including apoptosis. During cancerogenesis impaired apoptotic control facilitates survival of cells bearing molecular aberrations, contributing to their unrestricted proliferation and chemoresistance. Apparently, SR and hnRNP proteins regulate all levels of expression of apoptotic genes, including transcription initiation and elongation, alternative splicing, mRNA stability, translation, and protein degradation. The frequently disturbed expressions of SR/hnRNP proteins in cancers lead to impaired functioning of target apoptotic genes, including regulators of the extrinsic (Fas, caspase-8, caspase-2, c-FLIP) and the intrinsic pathway (Apaf-1, caspase-9, ICAD), genes encoding Bcl-2 proteins, IAPs, and p53 tumor suppressor. Prototypical members of SR/hnRNP families, SRSF1 and hnRNP A1, promote synthesis of anti-apoptotic splice variants of Bcl-x and Mcl-1, which results in attenuation of programmed cell death in breast cancer and chronic myeloid leukemia. SR/hnRNP proteins significantly affect responses to chemotherapy, acting as mediators or modulators of drug-induced apoptosis. Aberrant expression of SRSF1 and hnRNP K can interfere with tumor responses to chemotherapy in pancreatic and liver cancers. Currently, a number of splicing factor inhibitors is being tested in pre-clinical and clinical trials. In this review we discuss recent findings on the role of SR and hnRNP proteins in apoptotic control in cancer cells as well as their significance in anticancer treatments.
Collapse
Affiliation(s)
- Hanna Kędzierska
- Department of Biochemistry and Molecular Biology, Centre of Postgraduate Medical Education, ul. Marymoncka 99/103, 01-813 Warsaw, Poland
| | - Agnieszka Piekiełko-Witkowska
- Department of Biochemistry and Molecular Biology, Centre of Postgraduate Medical Education, ul. Marymoncka 99/103, 01-813 Warsaw, Poland.
| |
Collapse
|
22
|
Mihailovic MK, Chen A, Gonzalez-Rivera JC, Contreras LM. Defective Ribonucleoproteins, Mistakes in RNA Processing, and Diseases. Biochemistry 2017; 56:1367-1382. [PMID: 28206738 DOI: 10.1021/acs.biochem.6b01134] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Ribonucleoproteins (RNPs) are vital to many cellular events. To this end, many neurodegenerative diseases and cancers have been linked to RNP malfunction, particularly as this relates to defective processing of cellular RNA. The connection of RNPs and diseases has also propagated a shift of focus onto RNA targeting from traditional protein targeting treatments. However, therapeutic development in this area has been limited by incomplete molecular insight into the specific contributions of RNPs to disease. This review outlines the role of several RNPs in diseases, focusing on molecular defects in processes that affect proper RNA handling in the cell. This work also evaluates the contributions of recently developed methods to understanding RNP association and function. We review progress in this area by focusing on molecular malfunctions of RNPs associated with the onset and progression of several neurodegenerative diseases and cancer and conclude with a brief discussion of RNA-based therapeutic efforts.
Collapse
Affiliation(s)
- Mia K Mihailovic
- McKetta Department of Chemical Engineering, University of Texas at Austin , 200 East. Dean Keeton Street, Stop C0400, Austin, Texas 78712, United States
| | - Angela Chen
- McKetta Department of Chemical Engineering, University of Texas at Austin , 200 East. Dean Keeton Street, Stop C0400, Austin, Texas 78712, United States
| | - Juan C Gonzalez-Rivera
- McKetta Department of Chemical Engineering, University of Texas at Austin , 200 East. Dean Keeton Street, Stop C0400, Austin, Texas 78712, United States
| | - Lydia M Contreras
- McKetta Department of Chemical Engineering, University of Texas at Austin , 200 East. Dean Keeton Street, Stop C0400, Austin, Texas 78712, United States
| |
Collapse
|
23
|
SPSB1-mediated HnRNP A1 ubiquitylation regulates alternative splicing and cell migration in EGF signaling. Cell Res 2017; 27:540-558. [PMID: 28084329 DOI: 10.1038/cr.2017.7] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 12/06/2016] [Accepted: 12/09/2016] [Indexed: 12/31/2022] Open
Abstract
Extracellular signals have been shown to impact on alternative pre-mRNA splicing; however, the molecular mechanisms and biological significance of signal-induced splicing regulation remain largely unknown. Here, we report that epidermal growth factor (EGF) induces splicing changes through ubiquitylation of a well-known splicing regulator, hnRNP A1. EGF signaling upregulates an E3 ubiquitin (Ub) ligase adaptor, SPRY domain-containing SOCS box protein 1 (SPSB1), which recruits Elongin B/C-Cullin complexes to conjugate lysine 29-linked polyUb chains onto hnRNP A1. Importantly, SPSB1 and ubiquitylation of hnRNP A1 have a critical role in EGF-driven cell migration. Mechanistically, EGF-induced ubiquitylation of hnRNP A1 together with the activation of SR protein kinases (SRPKs) results in the upregulation of a Rac1 splicing isoform, Rac1b, to promote cell motility. These findings unravel a novel crosstalk between protein ubiquitylation and alternative splicing in EGF/EGF receptor signaling, and identify a new EGF/SPSB1/hnRNP A1/Rac1 axis in modulating cell migration, which may have important implications for cancer treatment.
Collapse
|
24
|
Roth S, Khalaila I. The effect of O -GlcNAcylation on hnRNP A1 translocation and interaction with transportin1. Exp Cell Res 2017; 350:210-217. [DOI: 10.1016/j.yexcr.2016.11.023] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 11/16/2016] [Accepted: 11/28/2016] [Indexed: 01/03/2023]
|
25
|
Ubiquitination of hnRNPA1 by TRAF6 links chronic innate immune signaling with myelodysplasia. Nat Immunol 2016; 18:236-245. [PMID: 28024152 PMCID: PMC5423405 DOI: 10.1038/ni.3654] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 11/30/2016] [Indexed: 12/24/2022]
Abstract
Toll-like receptor (TLR) activation contributes to premalignant hematologic conditions, such as myelodysplastic syndromes (MDS). TRAF6, a TLR-effector with ubiquitin (Ub) ligase activity, is overexpressed in MDS hematopoietic stem/progenitor cells (HSPC). Here we show that TRAF6 overexpression in mouse HSPC resulted in impaired hematopoiesis and bone marrow failure. Through the use of a global Ub screen, we identified hnRNPA1, an RNA-binding protein and auxiliary splicing factor, as a substrate of TRAF6. TRAF6 ubiquitination of hnRNPA1 regulated alternative splicing of Arhgap1, which resulted in Cdc42 activation and accounted for hematopoietic defects in TRAF6-expressing HSPC. These results implicate Ub signaling in coordinating RNA processing by TLR pathways during an immune response and in premalignant hematologic diseases, such as MDS.
Collapse
|
26
|
sST2 translation is regulated by FGF2 via an hnRNP A1-mediated IRES-dependent mechanism. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2016; 1859:848-59. [PMID: 27168114 DOI: 10.1016/j.bbagrm.2016.05.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 04/15/2016] [Accepted: 05/05/2016] [Indexed: 11/23/2022]
Abstract
Translation is an energy-intensive process and tightly regulated. Generally, translation is initiated in a cap-dependent manner. Under stress conditions, typically found within the tumor microenvironment in association with e.g. nutrient deprivation or hypoxia, cap-dependent translation decreases, and alternative modes of translation initiation become more important. Specifically, internal ribosome entry sites (IRES) facilitate translation of specific mRNAs under otherwise translation-inhibitory conditions. This mechanism is controlled by IRES trans-acting factors (ITAF), i.e. by RNA-binding proteins, which interact with and determine the activity of selected IRESs. We aimed at characterizing the translational regulation of the IL-33 decoy receptor sST2, which was enhanced by fibroblast growth factor 2 (FGF2). We identified and verified an IRES within the 5'UTR of sST2. Furthermore, we found that MEK/ERK signaling contributes to FGF2-induced, sST2-IRES activation and translation. Determination of the sST2-5'UTR structure by in-line probing followed by deletion analyses identified 23 nucleotides within the sST2-5'UTR to be required for optimal IRES activity. Finally, we show that the RNA-binding protein heterogeneous ribonucleoprotein A1 (hnRNP A1) binds to the sST2-5'UTR, acts as an ITAF, and thus controls the activity of the sST2-IRES and consequently sST2 translation. Specifically, FGF2 enhances nuclear-cytoplasmic translocation of hnRNP A1, which requires intact MEK/ERK activity. In summary, we provide evidence that the sST2-5'UTR contains an IRES element, which is activated by a MEK/ERK-dependent increase in cytoplasmic localization of hnRNP A1 in response to FGF2, enhancing the translation of sST2.
Collapse
|
27
|
Lipid accumulation stimulates the cap-independent translation of SREBP-1a mRNA by promoting hnRNP A1 binding to its 5'-UTR in a cellular model of hepatic steatosis. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:471-81. [PMID: 26869449 DOI: 10.1016/j.bbalip.2016.02.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 02/03/2016] [Accepted: 02/06/2016] [Indexed: 12/14/2022]
Abstract
Non-alcoholic fatty liver disease (NAFLD) is a chronic disease characterized by accumulation of lipid droplets in hepatocytes. Enhanced release of non-esterified fatty acids from adipose tissue accounts for a remarkable fraction of accumulated lipids. However, the de novo lipogenesis (DNL) is also implicated in the etiology of the NAFLD. Sterol Regulatory Element-Binding Protein-1 (SREBP-1) is a transcription factor modulating the expression of several lipogenic enzymes. In the present study, in order to investigate the effect of lipid droplet accumulation on DNL, we used a cellular model of steatosis represented by HepG2 cells cultured in a medium supplemented with free oleic and palmitic fatty acids (FFAs). We report that FFA supplementation induces the expression of genes coding for enzymes involved in the DNL as well as for the transcription factor SREBP-1a. The SREBP-1a mRNA translation, dependent on an internal ribosome entry site (IRES), and the SREBP-1a proteolytic cleavage are activated by FFAs. Furthermore, FFA treatment enhances the expression and the nucleus-cytosolic shuttling of hnRNP A1, a trans-activating factor of SREBP-1a IRES. The binding of hnRNP A1 to the SREBP-1a IRES is also increased upon FFA supplementation. The relocation of hnRNP A1 and the consequent increase of SREBP-1a translation are dependent on the p38 MAPK signal pathway, which is activated by FFAs. By RNA interference approach, we demonstrate that hnRNP A1 is implicated in the FFA-induced expression of SREBP-1a and of its target genes as well as in the lipid accumulation in cells.
Collapse
|
28
|
Knockdown of HNRNPA1 inhibits lung adenocarcinoma cell proliferation through cell cycle arrest at G0/G1 phase. Gene 2016; 576:791-7. [DOI: 10.1016/j.gene.2015.11.009] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 11/08/2015] [Accepted: 11/09/2015] [Indexed: 01/21/2023]
|
29
|
Horvilleur E, Wilson LA, Bastide A, Piñeiro D, Pöyry TAA, Willis AE. Cap-Independent Translation in Hematological Malignancies. Front Oncol 2015; 5:293. [PMID: 26734574 PMCID: PMC4685420 DOI: 10.3389/fonc.2015.00293] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 12/08/2015] [Indexed: 12/25/2022] Open
Abstract
Hematological malignancies are a heterogeneous group of diseases deriving from blood cells progenitors. Although many genes involved in blood cancers contain internal ribosome entry sites (IRESes), there has been only few studies focusing on the role of cap-independent translation in leukemia and lymphomas. Expression of IRES trans-acting factors can also be altered, and interestingly, BCL-ABL1 fusion protein expressed from “Philadelphia” chromosome, found in some types of leukemia, regulates several of them. A mechanism involving c-Myc IRES and cap-independent translation and leading to resistance to chemotherapy in multiple myeloma emphasize the contribution of cap-independent translation in blood cancers and the need for more work to be done to clarify the roles of known IRESes in pathology and response to chemotherapeutics.
Collapse
Affiliation(s)
| | | | | | - David Piñeiro
- Medical Research Council Toxicology Unit , Leicester , UK
| | | | - Anne E Willis
- Medical Research Council Toxicology Unit , Leicester , UK
| |
Collapse
|
30
|
Yu C, Guo J, Liu Y, Jia J, Jia R, Fan M. Oral squamous cancer cell exploits hnRNP A1 to regulate cell cycle and proliferation. J Cell Physiol 2015; 230:2252-61. [PMID: 25752295 DOI: 10.1002/jcp.24956] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 02/05/2015] [Indexed: 01/08/2023]
Abstract
Oral squamous cell carcinoma (OSCC) is a common human malignant tumor with high mortality. So far, the molecular pathogenesis of OSCC remains largely unclear. Heterogeneous nuclear ribonucleoprotein (hnRNP) A1 is an important multi-function splicing factor and closely related to tumorigenesis. hnRNP A1 is overexpressed in various tumors, and promotes aerobic glycolysis and elongation of telomere, but the function of hnRNP A1 in cell cycle and proliferation remains unclear. We found that hnRNP A1 was overexpressed in OSCC tissues, and was required for the growth of OSCC cells. Moreover, hnRNP A1 was highly expressed in the G2/M cell cycle phase. Knockdown of hnRNP A1 induced G2/M arrest. DNA microarray assay result showed that hnRNP A1 regulated the expression of a number of target genes associated with G2/M phase. Moreover, hnRNP A1 controlled the alternative splicing of CDK2 exon 5. These findings suggested that hnRNP A1 plays key roles in the regulation of cell cycle progression and pathogenesis of OSCC.
Collapse
Affiliation(s)
- Cheng Yu
- Hubei-MOST KLOS & KLOBME, School & Hospital of Stomatology, Wuhan University, Wuhan, PR China
| | - Jihua Guo
- Hubei-MOST KLOS & KLOBME, School & Hospital of Stomatology, Wuhan University, Wuhan, PR China
| | - Yu Liu
- College of Life Sciences, Wuhan University, Wuhan, PR China
| | - Jun Jia
- Hubei-MOST KLOS & KLOBME, School & Hospital of Stomatology, Wuhan University, Wuhan, PR China
| | - Rong Jia
- Hubei-MOST KLOS & KLOBME, School & Hospital of Stomatology, Wuhan University, Wuhan, PR China
| | - Mingwen Fan
- Hubei-MOST KLOS & KLOBME, School & Hospital of Stomatology, Wuhan University, Wuhan, PR China
| |
Collapse
|
31
|
Roy R, Durie D, Li H, Liu BQ, Skehel JM, Mauri F, Cuorvo LV, Barbareschi M, Guo L, Holcik M, Seckl MJ, Pardo OE. hnRNPA1 couples nuclear export and translation of specific mRNAs downstream of FGF-2/S6K2 signalling. Nucleic Acids Res 2014; 42:12483-97. [PMID: 25324306 PMCID: PMC4227786 DOI: 10.1093/nar/gku953] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The increased cap-independent translation of anti-apoptotic proteins is involved in the development of drug resistance in lung cancer but signalling events regulating this are poorly understood. Fibroblast growth factor 2 (FGF-2) signalling-induced S6 kinase 2 (S6K2) activation is necessary, but the downstream mediator(s) coupling this kinase to the translational response is unknown. Here, we show that S6K2 binds and phosphorylates hnRNPA1 on novel Ser4/6 sites, increasing its association with BCL-XL and XIAP mRNAs to promote their nuclear export. In the cytoplasm, phosphoS4/6-hnRNPA1 dissociates from these mRNAs de-repressing their IRES-mediated translation. This correlates with the phosphorylation-dependent association of hnRNPA1 with 14-3-3 leading to hnRNPA1 sumoylation on K183 and its re-import into the nucleus. A non-phosphorylatible, S4/6A mutant prevented these processes, hindering the pro-survival activity of FGF-2/S6K2 signalling. Interestingly, immunohistochemical staining of lung and breast cancer tissue samples demonstrated that increased S6K2 expression correlates with decreased cytoplasmic hnRNPA1 and increased BCL-XL expression. In short, phosphorylation on novel N-term sites of hnRNPA1 promotes translation of anti-apoptotic proteins and is indispensable for the pro-survival effects of FGF-2.
Collapse
Affiliation(s)
- Rajat Roy
- Division of Cancer, Department of Surgery and Cancer, 1st Floor, ICTEM Building, Hammersmith Hospitals Campus of Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Danielle Durie
- Apoptosis Research Centre, Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
| | - Hui Li
- Department of Biochemistry, Wuhan University, Wuhan, China
| | - Bing-Qian Liu
- Department of Biochemistry, Wuhan University, Wuhan, China
| | - John Mark Skehel
- Protein Analysis and Proteomics Laboratory, London Research Institute, South Mimms, EN6 3LD, UK
| | - Francesco Mauri
- Department of Histopathology, Hammersmith Hospital Campus, Imperial College, London W120NN, UK
| | | | | | - Lin Guo
- Department of Biochemistry, Wuhan University, Wuhan, China
| | - Martin Holcik
- Apoptosis Research Centre, Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
| | - Michael J Seckl
- Division of Cancer, Department of Surgery and Cancer, 1st Floor, ICTEM Building, Hammersmith Hospitals Campus of Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Olivier E Pardo
- Division of Cancer, Department of Surgery and Cancer, 1st Floor, ICTEM Building, Hammersmith Hospitals Campus of Imperial College London, Du Cane Road, London W12 0NN, UK
| |
Collapse
|
32
|
Barceló C, Etchin J, Mansour MR, Sanda T, Ginesta MM, Sanchez-Arévalo Lobo VJ, Real FX, Capellà G, Estanyol JM, Jaumot M, Look AT, Agell N. Ribonucleoprotein HNRNPA2B1 interacts with and regulates oncogenic KRAS in pancreatic ductal adenocarcinoma cells. Gastroenterology 2014; 147:882-892.e8. [PMID: 24998203 DOI: 10.1053/j.gastro.2014.06.041] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 06/26/2014] [Accepted: 06/29/2014] [Indexed: 12/20/2022]
Abstract
BACKGROUND & AIMS Development of pancreatic ductal adenocarcinoma (PDAC) involves activation of c-Ki-ras2 Kirsten rat sarcoma oncogene homolog (KRAS) signaling, but little is known about the roles of proteins that regulate the activity of oncogenic KRAS. We investigated the activities of proteins that interact with KRAS in PDAC cells. METHODS We used mass spectrometry to demonstrate that heterogeneous nuclear ribonucleoproteins (HNRNP) A2 and B1 (encoded by the gene HNRNPA2B1) interact with KRAS G12V. We used co-immunoprecipitation analyses to study interactions between HNRNPA2B1 and KRAS in KRAS-dependent and KRAS-independent PDAC cell lines. We knocked down HNRNPA2B1 using small hairpin RNAs and measured viability, anchorage-independent proliferation, and growth of xenograft tumors in mice. We studied KRAS phosphorylation using the Phos-tag system. RESULTS We found that interactions between HRNPA2B1 and KRAS correlated with KRAS-dependency of some human PDAC cell lines. Knock down of HNRNPA2B1 significantly reduced viability, anchorage-independent proliferation, and formation of xenograft tumors by KRAS-dependent PDAC cells. HNRNPA2B1 knock down also increased apoptosis of KRAS-dependent PDAC cells, inactivated c-akt murine thymoma oncogene homolog 1 signaling via mammalian target of rapamycin, and reduced interaction between KRAS and phosphatidylinositide 3-kinase. Interaction between HNRNPA2B1 and KRAS required KRAS phosphorylation at serine 181. CONCLUSIONS In KRAS-dependent PDAC cell lines, HNRNPA2B1 interacts with and regulates the activity of KRAS G12V and G12D. HNRNPA2B1 is required for KRAS activation of c-akt murine thymoma oncogene homolog 1-mammalian target of rapamycin signaling, interaction with phosphatidylinositide 3-kinase, and PDAC cell survival and tumor formation in mice. HNRNPA2B1 might be a target for treatment of pancreatic cancer.
Collapse
Affiliation(s)
- Carles Barceló
- Departament de Biologia Cellular, Immunologia i Neurociències, Facultat de Medicina, IDIBAPS, Universitat de Barcelona, Barcelona, Spain
| | - Julia Etchin
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts
| | - Marc R Mansour
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts
| | - Takaomi Sanda
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts; Cancer Science Institute of Singapore, National University of Singapore, Singapore
| | - Mireia M Ginesta
- Hereditary Cancer Program, Translational Research Laboratory, Catalan Institute of Oncology, ICO-IDIBELL, Hospitalet de Llobregat, Barcelona, Spain
| | - Victor J Sanchez-Arévalo Lobo
- Grupo de Carcinogénesis Epitelial, Programa de Patología Molecular, CNIO-Spanish National Cancer Research Center, Madrid, Spain
| | - Francisco X Real
- Grupo de Carcinogénesis Epitelial, Programa de Patología Molecular, CNIO-Spanish National Cancer Research Center, Madrid, Spain
| | - Gabriel Capellà
- Hereditary Cancer Program, Translational Research Laboratory, Catalan Institute of Oncology, ICO-IDIBELL, Hospitalet de Llobregat, Barcelona, Spain
| | - Josep M Estanyol
- Centres Científics i Tecnològics-UB (CCiTUB), Universitat de Barcelona, Barcelona, Spain
| | - Montserrat Jaumot
- Departament de Biologia Cellular, Immunologia i Neurociències, Facultat de Medicina, IDIBAPS, Universitat de Barcelona, Barcelona, Spain
| | - A Thomas Look
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts
| | - Neus Agell
- Departament de Biologia Cellular, Immunologia i Neurociències, Facultat de Medicina, IDIBAPS, Universitat de Barcelona, Barcelona, Spain.
| |
Collapse
|
33
|
Choi DB, Park MR, Kim HR, Jun CD, Kim HJ, Shim H, Kim YD, Choi C, Choi KH, Yun KJ, Chae SC, Park R, Choe SK, Lee YJ, Park DS. Aberrant proteomic expression of NSRP70 and its clinical implications and connection to the transcriptional level in adult acute leukemia. Leuk Res 2014; 38:1252-9. [PMID: 25176346 DOI: 10.1016/j.leukres.2014.08.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 08/02/2014] [Accepted: 08/03/2014] [Indexed: 11/30/2022]
Abstract
We investigated three splicing factor proteins (SFPs; NSRP70, SRSF1, and HNRNPA1) in 187 adults with and without acute leukemia (AL). We showed that NSRP70 is a novel lymphoblastic AL (ALL) surrogate marker, which presented excellent diagnostic accuracy (92%) and disappeared during remission. Its highest molecular weight form, but not total amount, was associated with adverse genetic abnormalities in myeloid AL (AML). Furthermore, we identified that these SFPs were more prevalent in ALL than in AML; were not correlated with their mRNA levels; and their formations in AL may occur without coding mutations and relate to post-translational modifications.
Collapse
Affiliation(s)
- Dan-Bee Choi
- Department of Laboratory Medicine, School of Medicine, Wonkwang University, Iksan, Republic of Korea; Center for Metabolic Function Regulation, Institute of Wonkwang Medical Science and Institute of Wonkwang Clinical Medicine, Wonkwang University, Iksan, Republic of Korea
| | - Moo-Rim Park
- Department of Internal Medicine, School of Medicine, Wonkwang University, Iksan, Republic of Korea
| | - Hak-Ryul Kim
- Department of Internal Medicine, School of Medicine, Wonkwang University, Iksan, Republic of Korea
| | - Chang-Duk Jun
- School of Life Sciences, Immune Synapse Research Center and Cell Dynamics Research Center, Gwangju Institute of Science and Technology, Gwangju, Republic of Korea
| | - Hyeoung-Joon Kim
- Department of Internal Medicine and Genome Research Center for Hematopoietic Diseases, Chonnam National University Hwasun Hospital, Hwasun-gun, Republic of Korea
| | - Hyeok Shim
- Department of Internal Medicine, School of Medicine, Wonkwang University, Iksan, Republic of Korea
| | - Young-Dae Kim
- School of Life Sciences, Immune Synapse Research Center and Cell Dynamics Research Center, Gwangju Institute of Science and Technology, Gwangju, Republic of Korea
| | - Chan Choi
- Department of Pathology and Genome Research Center for Hematopoietic Diseases, Chonnam National University Hwasun Hospital, Hwasun-gun, Republic of Korea
| | - Keum-Ha Choi
- Department of Pathology, School of Medicine, Wonkwang University, Iksan, Republic of Korea
| | - Ki Jung Yun
- Department of Pathology, School of Medicine, Wonkwang University, Iksan, Republic of Korea
| | - Soo-Cheon Chae
- Department of Pathology, School of Medicine, Wonkwang University, Iksan, Republic of Korea
| | - Raekil Park
- Center for Metabolic Function Regulation, Institute of Wonkwang Medical Science and Institute of Wonkwang Clinical Medicine, Wonkwang University, Iksan, Republic of Korea; Department of Microbiology, School of Medicine, Wonkwang University, Iksan, Republic of Korea
| | - Seong-Kyu Choe
- Center for Metabolic Function Regulation, Institute of Wonkwang Medical Science and Institute of Wonkwang Clinical Medicine, Wonkwang University, Iksan, Republic of Korea; Department of Microbiology, School of Medicine, Wonkwang University, Iksan, Republic of Korea
| | - Young-Jin Lee
- Department of Laboratory Medicine, School of Medicine, Wonkwang University, Iksan, Republic of Korea
| | - Do-Sim Park
- Department of Laboratory Medicine, School of Medicine, Wonkwang University, Iksan, Republic of Korea; Center for Metabolic Function Regulation, Institute of Wonkwang Medical Science and Institute of Wonkwang Clinical Medicine, Wonkwang University, Iksan, Republic of Korea.
| |
Collapse
|
34
|
Jabbour EJ, Hughes TP, Cortés JE, Kantarjian HM, Hochhaus A. Potential mechanisms of disease progression and management of advanced-phase chronic myeloid leukemia. Leuk Lymphoma 2014; 55:1451-62. [PMID: 24050507 PMCID: PMC4186697 DOI: 10.3109/10428194.2013.845883] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Despite vast improvements in the treatment of Philadelphia chromosome-positive chronic myeloid leukemia (CML) in chronic phase (CP), advanced stages of CML, accelerated phase or blast crisis, remain notoriously difficult to treat. Treatments that are highly effective against CML-CP produce disappointing results against advanced disease. Therefore, a primary goal of therapy should be to maintain patients in CP for as long as possible, by (1) striving for deep, early molecular response to treatment; (2) using tyrosine kinase inhibitors that lower risk of disease progression; and (3) more closely observing patients who demonstrate cytogenetic risk factors at diagnosis or during treatment.
Collapse
MESH Headings
- Blast Crisis/diagnosis
- Blast Crisis/etiology
- Blast Crisis/therapy
- Disease Management
- Disease Progression
- Humans
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/diagnosis
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/etiology
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/therapy
- Leukemia, Myeloid, Accelerated Phase/diagnosis
- Leukemia, Myeloid, Accelerated Phase/drug therapy
- Leukemia, Myeloid, Accelerated Phase/etiology
- Neoplasm Staging
- Prognosis
- Treatment Outcome
Collapse
Affiliation(s)
- Elias J. Jabbour
- Department of Leukemia, University of Texas MD Anderson Cancer Center, Houston, TX
| | - Timothy P. Hughes
- Department of Hematology, The University of Adelaide, Adelaide, Australia
| | - Jorge E. Cortés
- Department of Leukemia, University of Texas MD Anderson Cancer Center, Houston, TX
| | - Hagop M. Kantarjian
- Department of Leukemia, University of Texas MD Anderson Cancer Center, Houston, TX
| | - Andreas Hochhaus
- Abteilung Hämatologie/Onkologie, Universitätsklinikum Jena, Jena, Germany
| |
Collapse
|
35
|
Lee S, Levin M. Novel somatic single nucleotide variants within the RNA binding protein hnRNP A1 in multiple sclerosis patients. F1000Res 2014; 3:132. [PMID: 25254102 PMCID: PMC4168748 DOI: 10.12688/f1000research.4436.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/16/2014] [Indexed: 03/22/2024] Open
Abstract
Some somatic single nucleotide variants (SNVs) are thought to be pathogenic, leading to neurological disease. We hypothesized that heterogeneous nuclear ribonuclear protein A1 (hnRNP A1), an autoantigen associated with multiple sclerosis (MS) would contain SNVs. MS patients develop antibodies to hnRNP A1 (293-304), an epitope within the M9 domain (AA (268-305)) of hnRNP A1. M9 is hnRNP A1's nucleocytoplasmic transport domain, which binds transportin-1 (TPNO-1) and allows for hnRNP A1's transport into and out of the nucleus. Genomic DNA sequencing of M9 revealed nine novel SNVs that resulted in an amino acid substitution in MS patients that were not present in controls. SNVs occurred within the TPNO-1 binding domain (hnRNP A1 (268-289)) and the MS IgG epitope (hnRNP A1 (293-304)), within M9. In contrast to the nuclear localization of wild type (WT) hnRNP A1, mutant hnRNP A1 mis-localized to the cytoplasm, co-localized with stress granules and caused cellular apoptosis. Whilst WT hnRNP A1 bound TPNO-1, mutant hnRNP A1 showed reduced TPNO-1 binding. These data suggest SNVs in hnRNP A1 might contribute to pathogenesis of MS.
Collapse
Affiliation(s)
- Sangmin Lee
- Research Service, Veterans Affairs Medical Center, Memphis, TN, USA
- Department of Neurology, University of Tennessee Health Science Center, Memphis, TN, USA
- Neuroscience Institute, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Michael Levin
- Research Service, Veterans Affairs Medical Center, Memphis, TN, USA
- Department of Neurology, University of Tennessee Health Science Center, Memphis, TN, USA
- Department of Anatomy/Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA
- Neuroscience Institute, University of Tennessee Health Science Center, Memphis, TN, USA
| |
Collapse
|
36
|
Lee S, Levin M. Novel somatic single nucleotide variants within the RNA binding protein hnRNP A1 in multiple sclerosis patients. F1000Res 2014; 3:132. [PMID: 25254102 PMCID: PMC4168748 DOI: 10.12688/f1000research.4436.2] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/16/2014] [Indexed: 12/13/2022] Open
Abstract
Some somatic single nucleotide variants (SNVs) are thought to be pathogenic, leading to neurological disease. We hypothesized that heterogeneous nuclear ribonuclear protein A1 (hnRNP A1), an autoantigen associated with multiple sclerosis (MS) would contain SNVs. MS patients develop antibodies to hnRNP A1 (293-304), an epitope within the M9 domain (AA (268-305)) of hnRNP A1. M9 is hnRNP A1's nucleocytoplasmic transport domain, which binds transportin-1 (TPNO-1) and allows for hnRNP A1's transport into and out of the nucleus. Genomic DNA sequencing of M9 revealed nine novel SNVs that resulted in an amino acid substitution in MS patients that were not present in controls. SNVs occurred within the TPNO-1 binding domain (hnRNP A1 (268-289)) and the MS IgG epitope (hnRNP A1 (293-304)), within M9. In contrast to the nuclear localization of wild type (WT) hnRNP A1, mutant hnRNP A1 mis-localized to the cytoplasm, co-localized with stress granules and caused cellular apoptosis. Whilst WT hnRNP A1 bound TPNO-1, mutant hnRNP A1 showed reduced TPNO-1 binding. These data suggest SNVs in hnRNP A1 might contribute to pathogenesis of MS.
Collapse
Affiliation(s)
- Sangmin Lee
- Research Service, Veterans Affairs Medical Center, Memphis, TN, USA
- Department of Neurology, University of Tennessee Health Science Center, Memphis, TN, USA
- Neuroscience Institute, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Michael Levin
- Research Service, Veterans Affairs Medical Center, Memphis, TN, USA
- Department of Neurology, University of Tennessee Health Science Center, Memphis, TN, USA
- Department of Anatomy/Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA
- Neuroscience Institute, University of Tennessee Health Science Center, Memphis, TN, USA
| |
Collapse
|
37
|
Huang Y, Lin L, Yu X, Wen G, Pu X, Zhao H, Fang C, Zhu J, Ye S, Zhang L, Xiao Q. Functional involvements of heterogeneous nuclear ribonucleoprotein A1 in smooth muscle differentiation from stem cells in vitro and in vivo. Stem Cells 2014; 31:906-17. [PMID: 23335105 DOI: 10.1002/stem.1324] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Accepted: 12/14/2012] [Indexed: 02/02/2023]
Abstract
To investigate the functional involvements of heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1) in smooth muscle cell (SMC) differentiation from stem cells, embryonic stem cells were cultivated on collagen IV-coated plates to allow for SMC differentiation. We found that hnRNPA1 gene and protein expression was upregulated significantly during differentiation and coexpressed with SMC differentiation markers in the stem cell-derived SMCs as well as embryonic SMCs of 12.5 days of mouse embryos. hnRNPA1 knockdown resulted in downregulation of smooth muscle markers and transcription factors, while enforced expression of hnRNPA1 enhanced the expression of these genes. Importantly, knockdown of hnRNPA1 also resulted in impairment of SMC differentiation in vivo. Moreover, we demonstrated that hnRNPA1 could transcriptionally regulate SMC gene expression through direct binding to promoters of Acta2 and Tagln genes using luciferase and chromatin immunoprecipitation assays. We further demonstrated that the binding sites for serum response factor (SRF), a well-investigated SMC transcription factor, within the promoter region of the Acta2 and Tagln genes were responsible for hnRNPA1-mediated Acta2 and Tagln gene expression using in vitro site-specific mutagenesis and luciferase activity analyses. Finally, we also demonstrated that hnRNPA1 upregulated the expression of SRF, myocyte-specific enhancer factor 2c (MEF2c), and myocardin through transcriptional activation and direct binding to promoters of the SRF, MEF2c, and Myocd genes. Our findings demonstrated that hnRNPA1 plays a functional role in SMC differentiation from stem cells in vitro and in vivo. This indicates that hnRNPA1 is a potential modulating target for deriving SMCs from stem cells and cardiovascular regenerative medicine.
Collapse
Affiliation(s)
- Yuan Huang
- Centre for Clinical Pharmacology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Zhou H, Ge Y, Sun L, Ma W, Wu J, Zhang X, Hu X, Eaves CJ, Wu D, Zhao Y. Growth arrest specific 2 is up-regulated in chronic myeloid leukemia cells and required for their growth. PLoS One 2014; 9:e86195. [PMID: 24465953 PMCID: PMC3897655 DOI: 10.1371/journal.pone.0086195] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Accepted: 12/09/2013] [Indexed: 12/18/2022] Open
Abstract
Although the generation of BCR-ABL is the molecular hallmark of chronic myeloid leukemia (CML), the comprehensive molecular mechanisms of the disease remain unclear yet. Growth arrest specific 2 (GAS2) regulates multiple cellular functions including cell cycle, apoptosis and calpain activities. In the present study, we found GAS2 was up-regulated in CML cells including CD34+ progenitor cells compared to their normal counterparts. We utilized RNAi and the expression of dominant negative form of GAS2 (GAS2DN) to target GAS2, which resulted in calpain activity enhancement and growth inhibition of both K562 and MEG-01 cells. Targeting GAS2 also sensitized K562 cells to Imatinib mesylate (IM). GAS2DN suppressed the tumorigenic ability of MEG-01 cells and impaired the tumour growth as well. Moreover, the CD34+ cells from CML patients and healthy donors were transduced with control and GAS2DN lentiviral vectors, and the CD34+ transduced (YFP+) progeny cells (CD34+YFP+) were plated for colony-forming cell (CFC) assay. The results showed that GAS2DN inhibited the CFC production of CML cells by 57±3% (n = 3), while affected those of normal hematopoietic cells by 31±1% (n = 2). Next, we found the inhibition of CML cells by GAS2DN was dependent on calpain activity but not the degradation of beta-catenin. Lastly, we generated microarray data to identify the differentially expressed genes upon GAS2DN and validated that the expression of HNRPDL, PTK7 and UCHL5 was suppressed by GAS2DN. These 3 genes were up-regulated in CML cells compared to normal control cells and the growth of K562 cells was inhibited upon HNRPDL silence. Taken together, we have demonstrated that GAS2 is up-regulated in CML cells and the inhibition of GAS2 impairs the growth of CML cells, which indicates GAS2 is a novel regulator of CML cells and a potential therapeutic target of this disease.
Collapse
MESH Headings
- Animals
- Calpain/metabolism
- Cell Line, Tumor
- Cell Proliferation
- Gene Expression Profiling
- Gene Expression Regulation, Leukemic
- Gene Knockdown Techniques
- Humans
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology
- Mice
- Mice, Nude
- Microfilament Proteins/metabolism
- Neoplastic Stem Cells/metabolism
- Neoplastic Stem Cells/pathology
- RNA Interference
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Transcriptome/genetics
- Transduction, Genetic
- Tumor Stem Cell Assay
- Up-Regulation
- beta Catenin/metabolism
Collapse
Affiliation(s)
- Haixia Zhou
- The First Affiliated Hospital, Jiangsu Institute of Hematology, Key Laboratory of Thrombosis and Hemostasis of Ministry of Health, Soochow University, Suzhou, Jiangsu Province, P.R. China
- Cyrus Tang Hematology Center, Soochow University, Suzhou, Jiangsu Province, P.R. China
| | - Yue Ge
- Cyrus Tang Hematology Center, Soochow University, Suzhou, Jiangsu Province, P.R. China
| | - Lili Sun
- Cyrus Tang Hematology Center, Soochow University, Suzhou, Jiangsu Province, P.R. China
| | - Wenjuan Ma
- Cyrus Tang Hematology Center, Soochow University, Suzhou, Jiangsu Province, P.R. China
| | - Jie Wu
- Cyrus Tang Hematology Center, Soochow University, Suzhou, Jiangsu Province, P.R. China
| | - Xiuyan Zhang
- Cyrus Tang Hematology Center, Soochow University, Suzhou, Jiangsu Province, P.R. China
| | - Xiaohui Hu
- The First Affiliated Hospital, Jiangsu Institute of Hematology, Key Laboratory of Thrombosis and Hemostasis of Ministry of Health, Soochow University, Suzhou, Jiangsu Province, P.R. China
| | - Connie J. Eaves
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, Canada
| | - Depei Wu
- The First Affiliated Hospital, Jiangsu Institute of Hematology, Key Laboratory of Thrombosis and Hemostasis of Ministry of Health, Soochow University, Suzhou, Jiangsu Province, P.R. China
- * E-mail: (DW); (YZ)
| | - Yun Zhao
- Cyrus Tang Hematology Center, Soochow University, Suzhou, Jiangsu Province, P.R. China
- * E-mail: (DW); (YZ)
| |
Collapse
|
39
|
Walker CJ, Oaks JJ, Santhanam R, Neviani P, Harb JG, Ferenchak G, Ellis JJ, Landesman Y, Eisfeld AK, Gabrail NY, Smith CL, Caligiuri MA, Hokland P, Roy DC, Reid A, Milojkovic D, Goldman JM, Apperley J, Garzon R, Marcucci G, Shacham S, Kauffman MG, Perrotti D. Preclinical and clinical efficacy of XPO1/CRM1 inhibition by the karyopherin inhibitor KPT-330 in Ph+ leukemias. Blood 2013; 122:3034-44. [PMID: 23970380 PMCID: PMC3811176 DOI: 10.1182/blood-2013-04-495374] [Citation(s) in RCA: 115] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 08/11/2013] [Indexed: 02/07/2023] Open
Abstract
As tyrosine kinase inhibitors (TKIs) fail to induce long-term response in blast crisis chronic myelogenous leukemia (CML-BC) and Philadelphia chromosome-positive (Ph(+)) acute lymphoblastic leukemia (ALL), novel therapies targeting leukemia-dysregulated pathways are necessary. Exportin-1 (XPO1), also known as chromosome maintenance protein 1, regulates cell growth and differentiation by controlling the nucleocytoplasmic trafficking of proteins and RNAs, some of which are aberrantly modulated in BCR-ABL1(+) leukemias. Using CD34(+) progenitors from CML, B-ALL, and healthy individuals, we found that XPO1 expression was markedly increased, mostly in a TKI-sensitive manner, in CML-BC and Ph(+) B-ALL. Notably, XPO1 was also elevated in Ph(-) B-ALL. Moreover, the clinically relevant XPO1 inhibitor KPT-330 strongly triggered apoptosis and impaired the clonogenic potential of leukemic, but not normal, CD34(+) progenitors, and increased survival of BCR-ABL1(+) mice, 50% of which remained alive and, mostly, became BCR-ABL1 negative. Moreover, KPT-330 compassionate use in a patient with TKI-resistant CML undergoing disease progression significantly reduced white blood cell count, blast cells, splenomegaly, lactate dehydrogenase levels, and bone pain. Mechanistically, KPT-330 altered the subcellular localization of leukemia-regulated factors including RNA-binding heterogeneous nuclear ribonucleoprotein A1 and the oncogene SET, thereby inducing reactivation of protein phosphatase 2A tumor suppressor and inhibition of BCR-ABL1 in CML-BC cells. Because XPO1 is important for leukemic cell survival, KPT-330 may represent an alternative therapy for TKI-refractory Ph(+) leukemias.
Collapse
MESH Headings
- Adult
- Animals
- Antigens, CD34/genetics
- Antigens, CD34/metabolism
- Antineoplastic Agents/pharmacology
- Apoptosis/drug effects
- Cell Proliferation/drug effects
- Clinical Trials, Phase I as Topic
- DNA-Binding Proteins
- Drug Evaluation, Preclinical
- Fusion Proteins, bcr-abl/antagonists & inhibitors
- Fusion Proteins, bcr-abl/genetics
- Fusion Proteins, bcr-abl/metabolism
- Gene Expression Regulation, Leukemic/drug effects
- Histone Chaperones/antagonists & inhibitors
- Histone Chaperones/genetics
- Histone Chaperones/metabolism
- Humans
- Hydrazines/pharmacology
- Karyopherins/antagonists & inhibitors
- Karyopherins/genetics
- Karyopherins/metabolism
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology
- Male
- Mice
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/drug therapy
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/pathology
- Protein Kinase Inhibitors/pharmacology
- Protein Transport
- Receptors, Cytoplasmic and Nuclear/antagonists & inhibitors
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/metabolism
- Ribonucleoproteins/antagonists & inhibitors
- Ribonucleoproteins/genetics
- Ribonucleoproteins/metabolism
- Transcription Factors/antagonists & inhibitors
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Triazoles/pharmacology
- Exportin 1 Protein
Collapse
Affiliation(s)
- Christopher J Walker
- Human Cancer Genetics Program, Department Molecular Virology Immunology and Medical Genetics
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Functions of heterogeneous nuclear ribonucleoproteins in stem cell potency and differentiation. BIOMED RESEARCH INTERNATIONAL 2013; 2013:623978. [PMID: 23984388 PMCID: PMC3745930 DOI: 10.1155/2013/623978] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Revised: 07/02/2013] [Accepted: 07/04/2013] [Indexed: 12/26/2022]
Abstract
Stem cells possess huge importance in developmental biology, disease modelling, cell replacement therapy, and tissue engineering in regenerative medicine because they have the remarkable potential for self-renewal and to differentiate into almost all the cell types in the human body. Elucidation of molecular mechanisms regulating stem cell potency and differentiation is essential and critical for extensive application. Heterogeneous nuclear ribonucleoproteins (hnRNPs) are modular proteins consisting of RNA-binding motifs and auxiliary domains characterized by extensive and divergent functions in nucleic acid metabolism. Multiple roles of hnRNPs in transcriptional and posttranscriptional regulation enable them to be effective gene expression regulators. More recent findings show that hnRNP proteins are crucial factors implicated in maintenance of stem cell self-renewal and pluripotency and cell differentiation. The hnRNPs interact with certain sequences in target gene promoter regions to initiate transcription. In addition, they recognize 3′UTR or 5′UTR of specific gene mRNA forming mRNP complex to regulate mRNA stability and translation. Both of these regulatory pathways lead to modulation of gene expression that is associated with stem cell proliferation, cell cycle control, pluripotency, and committed differentiation.
Collapse
|
41
|
Harb JG, Neviani P, Chyla BJ, Ellis JJ, Ferenchak GJ, Oaks JJ, Walker CJ, Hokland P, Roy DC, Caligiuri MA, Marcucci G, Huettner CS, Perrotti D. Bcl-xL anti-apoptotic network is dispensable for development and maintenance of CML but is required for disease progression where it represents a new therapeutic target. Leukemia 2013; 27:1996-2005. [PMID: 23670294 DOI: 10.1038/leu.2013.151] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Revised: 04/16/2013] [Accepted: 05/01/2013] [Indexed: 12/30/2022]
Abstract
The dismal outcome of blast crisis chronic myelogenous leukemia (CML-BC) patients underscores the need for a better understanding of the mechanisms responsible for the development of drug resistance. Altered expression of the anti-apoptoticBcl-xL has been correlated with BCR-ABL leukemogenesis; however, its involvement in the pathogenesis and evolution of CML has not been formally demonstrated yet. Thus, we generated an inducible mouse model in which simultaneous expression of p210-BCR-ABL1 and deletion of bcl-x occurs within hematopoietic stem and progenitor cells. Absence of Bcl-xL did not affect development of the chronic phase-like myeloproliferative disease, but none of the deficient mice progressed to an advanced phenotype, suggesting the importance of Bcl-xL in survival of progressing early progenitor cells. Indeed, pharmacological antagonism of Bcl-xL, with ABT-263, combined with PP242-induced activation of BAD markedly augmented apoptosis of CML-BC cell lines and primary CD34(+) progenitors but not those from healthy donors, regardless of drug resistance induced by bone marrow stromal cell-generated signals. Moreover, studies in which BAD or Bcl-xL expression was molecularly altered strongly support their involvement in ABT-263/PP242-induced apoptosis of CML-BC progenitors. Thus, suppression of the antiapoptotic potential of Bcl-xL together with BAD activation represents an effective pharmacological approach for patients undergoing blastic transformation.
Collapse
Affiliation(s)
- J G Harb
- 1] Human Cancer Genetics Program, Department Molecular Virology Immunology and Medical Genetics, Columbus, OH, USA [2] Blood Center of Wisconsin, Blood Research Institute, Milwaukee, WI, USA
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
hnRNP A1 mediates the activation of the IRES-dependent SREBP-1a mRNA translation in response to endoplasmic reticulum stress. Biochem J 2013; 449:543-53. [PMID: 23106379 DOI: 10.1042/bj20120906] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A growing amount of evidence suggests the involvement of ER (endoplasmic reticulum) stress in lipid metabolism and in the development of some liver diseases such as steatosis. The transcription factor SREBP-1 (sterol-regulatory-element-binding protein 1) modulates the expression of several enzymes involved in lipid synthesis. Previously, we showed that ER stress increased the SREBP-1a protein level in HepG2 cells, by inducing a cap-independent translation of SREBP-1a mRNA, through an IRES (internal ribosome entry site), located in its leader region. In the present paper, we report that the hnRNP A1 (heterogeneous nuclear ribonucleoprotein A1) interacts with 5'-UTR (untranslated region) of SREBP-1a mRNA, as an ITAF (IRES trans-acting factor), regulating SREBP-1a expression in HepG2 cells and in primary rat hepatocytes. Overexpression of hnRNP A1 in HepG2 cells and in rat hepatocytes increased both the SREBP-1a IRES activity and SREBP-1a protein level. Knockdown of hnRNP A1 by small interfering RNA reduced either the SREBP-1a IRES activity or SREBP-1a protein level. hnRNP A1 mediates the increase of SREBP-1a protein level and SREBP-1a IRES activity in Hep G2 cells and in rat hepatocytes upon tunicamycin- and thapsigargin-induced ER stress. The induced ER stress triggered the cytosolic relocation of hnRNP A1 and caused the increase in hnRNP A1 bound to the SREBP-1a 5'-UTR. These data indicate that hnRNP A1 participates in the IRES-dependent translation of SREBP-1a mRNA through RNA-protein interaction. A different content of hnRNP A1 was found in the nuclei from high-fat-diet-fed mice liver compared with standard-diet-fed mice liver, suggesting an involvement of ER stress-mediated hnRNP A1 subcellular redistribution on the onset of metabolic disorders.
Collapse
|
43
|
Turroni S, Tolomeo M, Mamone G, Picariello G, Giacomini E, Brigidi P, Roberti M, Grimaudo S, Pipitone RM, Di Cristina A, Recanatini M. A natural-like synthetic small molecule impairs bcr-abl signaling cascades and induces megakaryocyte differentiation in erythroleukemia cells. PLoS One 2013; 8:e57650. [PMID: 23460890 PMCID: PMC3584047 DOI: 10.1371/journal.pone.0057650] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Accepted: 01/24/2013] [Indexed: 11/28/2022] Open
Abstract
Over the past years, we synthesized a series of new molecules that are hybrids of spirocyclic ketones as complexity-bearing cores with bi- and ter-phenyls as privileged fragments. Some of these newly-shaped small molecules showed antiproliferative, pro-apoptotic and differentiating activity in leukemia cell lines. In the present study, to investigate more in depth the mechanisms of action of these molecules, the protein expression profiles of K562 cells treated with or without the compounds IND_S1, MEL_T1, IND_S7 and MEL_S3 were analyzed using two-dimensional gel electrophoresis coupled with mass spectrometry. Proteome comparisons revealed several differentially expressed proteins, mainly related to cellular metabolism, chaperone activity, cytoskeletal organization and RNA biogenesis. The major results were validated by Western blot and qPCR. To attempt integrating findings into a cellular signaling context, proteomic data were explored using MetaCore. Network analysis highlighted relevant relationships between the identified proteins and additional potential effectors. Notably, qPCR validation of central hubs showed that the compound MEL_S3 induced high mRNA levels of the transcriptional factors EGR1 and HNF4-alpha; the latter to our knowledge is reported here for the first time to be present in K562 cells. Consistently with the known EGR1 involvement in the regulation of differentiation along megakaryocyte lineage, MEL_S3-treated leukemia cells showed a marked expression of glycoprotein IIb/IIIa (CD41) and glycoprotein Ib (CD42), two important cell markers in megakaryocytic differentiation, together with morphological aspects of megakaryoblasts and megakaryocytes.
Collapse
MESH Headings
- Biomarkers, Tumor/metabolism
- Cell Differentiation/drug effects
- Cell Differentiation/genetics
- Cell Shape/drug effects
- Cluster Analysis
- Fusion Proteins, bcr-abl/metabolism
- Gene Expression Regulation, Leukemic/drug effects
- Humans
- K562 Cells
- Leukemia, Erythroblastic, Acute/genetics
- Leukemia, Erythroblastic, Acute/pathology
- Megakaryocytes/drug effects
- Megakaryocytes/metabolism
- Megakaryocytes/pathology
- Multivariate Analysis
- Neoplasm Proteins/genetics
- Neoplasm Proteins/metabolism
- Proteome/metabolism
- Proteomics
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Reproducibility of Results
- Signal Transduction/drug effects
- Signal Transduction/genetics
- Small Molecule Libraries/chemistry
- Small Molecule Libraries/pharmacology
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
Collapse
Affiliation(s)
- Silvia Turroni
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
| | - Manlio Tolomeo
- Interdepartmental Center of Research in Clinical Oncology and Department of Infectious Diseases, University of Palermo, Palermo, Italy
| | | | | | - Elisa Giacomini
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
| | - Patrizia Brigidi
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
| | - Marinella Roberti
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
- * E-mail:
| | - Stefania Grimaudo
- Interdepartmental Center of Research in Clinical Oncology and Department of Infectious Diseases, University of Palermo, Palermo, Italy
| | - Rosaria Maria Pipitone
- Interdepartmental Center of Research in Clinical Oncology and Department of Infectious Diseases, University of Palermo, Palermo, Italy
| | - Antonietta Di Cristina
- Interdepartmental Center of Research in Clinical Oncology and Department of Infectious Diseases, University of Palermo, Palermo, Italy
| | - Maurizio Recanatini
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
| |
Collapse
|
44
|
Gurkan UA, Golden R, Kishore V, Riley CP, Adamec J, Akkus O. Immune and inflammatory pathways are involved in inherent bone marrow ossification. Clin Orthop Relat Res 2012; 470:2528-40. [PMID: 22798134 PMCID: PMC3830098 DOI: 10.1007/s11999-012-2459-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Bone marrow plays a key role in bone formation and healing. Although a subset of marrow explants ossifies in vitro without excipient osteoinductive factors, some explants do not undergo ossification. The disparity of outcome suggests a significant heterogeneity in marrow tissue in terms of its capacity to undergo osteogenesis. QUESTIONS/PURPOSES We sought to identify: (1) proteins and signaling pathways associated with osteogenesis by contrasting the proteomes of ossified and poorly ossified marrow explants; and (2) temporal changes in proteome and signaling pathways of marrow ossification in the early and late phases of bone formation. METHODS Explants of marrow were cultured. Media conditioned by ossified (n = 4) and poorly ossified (n = 4) subsets were collected and proteins unique to each group were identified by proteomic analysis. Proteomic data were processed to assess proteins specific to the early phase (Days 1-14) and late phase (Days 15-28) of the culture period. Pathways involved in bone marrow ossification were identified through bioinformatics. RESULTS Twenty-eight proteins were unique to ossified samples and eight were unique to poorly ossified ones. Twelve proteins were expressed during the early phase and 15 proteins were specific to the late phase. Several identified pathways corroborated those reported for bone formation in the literature. Immune and inflammatory pathways were specific to ossified samples. CONCLUSIONS The marrow explant model indicates the inflammatory and immune pathways to be an integral part of the osteogenesis process.
Collapse
Affiliation(s)
- Umut Atakan Gurkan
- />Harvard-MIT Division of Health Sciences and Technology, Brigham and Women’s Hospital, Harvard Medical School, 65 Landsdowne Street, PRB 252, Cambridge, MA 02139 USA
| | - Ryan Golden
- />Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN USA
| | - Vipuil Kishore
- />Department of Mechanical and Aerospace Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106 USA
| | - Catherine P. Riley
- />Department of Research and Development Pathology Associates, Medical Laboratories, Spokane, WA 99204 USA
| | - Jiri Adamec
- />Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE USA
| | - Ozan Akkus
- />Department of Mechanical and Aerospace Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106 USA
- />Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106 USA
- />Department of Orthopaedics, University Hospitals of Cleveland, Cleveland, OH USA
| |
Collapse
|
45
|
Casolari DA, Makri M, Yoshida C, Muto A, Igarashi K, Melo JV. Transcriptional suppression of BACH2 by the Bcr-Abl oncoprotein is mediated by PAX5. Leukemia 2012; 27:409-15. [DOI: 10.1038/leu.2012.220] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
46
|
Bieler S, Hammer E, Gesell-Salazar M, Völker U, Stangl K, Meiners S. Low dose proteasome inhibition affects alternative splicing. J Proteome Res 2012; 11:3947-54. [PMID: 22702956 DOI: 10.1021/pr300435c] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Protein degradation by the ubiquitin proteasome system ensures controlled degradation of structural proteins, signaling mediators, and transcription factors. Inhibition of proteasome function by specific proteasome inhibitors results in dose-dependent cellular effects ranging from induction of apoptosis to protective stress responses. The present study seeks to identify nuclear regulators mediating the protective stress response to low dose proteasome inhibition. Primary human endothelial cells were treated with low doses of the proteasome inhibitor MG132 for 2 h, and proteomic analysis of nuclear extracts was performed. Using a 2-D differential in gel electrophoresis (DIGE) approach, we identified more than 24 splice factors to be differentially regulated by low dose proteasome inhibition. In particular, several isoforms of hnRNPA1 were shown to be increased, pointing toward altered posttranslational modification of hnRNPA1 upon proteasome inhibition. Elevated levels of splice factors were associated with a different alternative splicing pattern in response to proteasome inhibition as determined by Affymetrix exon array profiling. Of note, we observed alternative RNA processing for stress associated genes such as caspases and heat shock proteins. Our study provides first evidence that low dose proteasome inhibition affects posttranscriptional regulation of splice factors and early alternative splicing events.
Collapse
Affiliation(s)
- Sven Bieler
- Medizinische Klinik mit Schwerpunkt Kardiologie und Angiologie, Charité-Universitätsmedizin, Berlin, Germany
| | | | | | | | | | | |
Collapse
|
47
|
Identification of nuclear protein targets for six leukemogenic tyrosine kinases governed by post-translational regulation. PLoS One 2012; 7:e38928. [PMID: 22745689 PMCID: PMC3382166 DOI: 10.1371/journal.pone.0038928] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Accepted: 05/14/2012] [Indexed: 11/19/2022] Open
Abstract
Mutated tyrosine kinases are associated with a number of different haematological malignancies including myeloproliferative disorders, lymphoma and acute myeloid leukaemia. The potential commonalities in the action of six of these leukemogenic proteins on nuclear proteins were investigated using systematic proteomic analysis. The effects on over 3600 nuclear proteins and 1500 phosphopeptide sites were relatively quantified in seven isogenic cell lines. The effects of the kinases were diverse although some commonalities were found. Comparison of the nuclear proteomic data with transcriptome data and cytoplasmic proteomic data indicated that the major changes are due to post-translational mechanisms rather than changes in mRNA or protein distribution. Analysis of the promoter regions of genes whose protein levels changed in response to the kinases showed the most common binding site found was that for NFκB whilst other sites such as those for the glucocorticoid receptor were also found. Glucocorticoid receptor levels and phosphorylation were decreased by all 6 PTKs. Whilst Glucocorticoid receptor action can potentiate NFκB action those proteins where genes have NFκB binding sites were in often regulated post-translationally. However all 6 PTKs showed evidence of NFkB pathway modulation via activation via altered IkB and NFKB levels. Validation of a common change was also undertaken with PMS2, a DNA mismatch repair protein. PMS2 nuclear levels were decreased in response to the expression of all 6 kinases, with no concomitant change in mRNA level or cytosolic protein level. Response to thioguanine, that requires the mismatch repair pathway, was modulated by all 6 oncogenic kinases. In summary common targets for 6 oncogenic PTKs have been found that are regulated by post-translational mechanisms. They represent potential new avenues for therapies but also demonstrate the post-translational regulation is a key target of leukaemogenic kinases.
Collapse
|
48
|
Extensive gene-specific translational reprogramming in a model of B cell differentiation and Abl-dependent transformation. PLoS One 2012; 7:e37108. [PMID: 22693568 PMCID: PMC3365017 DOI: 10.1371/journal.pone.0037108] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Accepted: 04/15/2012] [Indexed: 01/19/2023] Open
Abstract
To what extent might the regulation of translation contribute to differentiation programs, or to the molecular pathogenesis of cancer? Pre-B cells transformed with the viral oncogene v-Abl are suspended in an immortalized, cycling state that mimics leukemias with a BCR-ABL1 translocation, such as Chronic Myelogenous Leukemia (CML) and Acute Lymphoblastic Leukemia (ALL). Inhibition of the oncogenic Abl kinase with imatinib reverses transformation, allowing progression to the next stage of B cell development. We employed a genome-wide polysome profiling assay called Gradient Encoding to investigate the extent and potential contribution of translational regulation to transformation and differentiation in v-Abl-transformed pre-B cells. Over half of the significantly translationally regulated genes did not change significantly at the level of mRNA abundance, revealing biology that might have been missed by measuring changes in transcript abundance alone. We found extensive, gene-specific changes in translation affecting genes with known roles in B cell signaling and differentiation, cancerous transformation, and cytoskeletal reorganization potentially affecting adhesion. These results highlight a major role for gene-specific translational regulation in remodeling the gene expression program in differentiation and malignant transformation.
Collapse
|
49
|
Ziaei S, Shimada N, Kucharavy H, Hubbard K. MNK1 expression increases during cellular senescence and modulates the subcellular localization of hnRNP A1. Exp Cell Res 2011; 318:500-8. [PMID: 22227431 DOI: 10.1016/j.yexcr.2011.12.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Revised: 12/14/2011] [Accepted: 12/16/2011] [Indexed: 12/15/2022]
Abstract
Heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) is an RNA-binding protein that modulates splice site usage, polyadenylation, and cleavage efficiency. This protein has also been implicated in mRNA stability and transport from the nucleus. We have previously demonstrated that hnRNP A1 had diminished protein levels and showed cytoplasmic accumulation in senescent human diploid fibroblasts. Furthermore, we have shown that inhibition of p38 MAPK, a key regulator of cellular senescence, elevated hnRNP A1 protein levels and inhibited hnRNP A1 cytoplasmic localization. In this study, we have explored the possible involvement of MNK1, one of the downstream effector of p38 MAPK, in the regulation of hnRNP A1. We have demonstrated that pharmacological inhibition of MNK1 by CGP 57380 decreased the phosphorylation levels of hnRNP A1 in young and senescent fibroblast cells and blocked the cytoplasmic accumulation of hnRNP A1 in senescent cells. In addition, MNK1 formed a complex with hnRNP A1 in vivo. The expression levels of MNK1, phospho-MNK1, and phospho-eIF4E proteins were found to be elevated in senescent cells. These data suggest that MNK1 regulates the phosphorylation and the subcellular distribution of hnRNP A1 and that MNK1 may play a role in the induction of senescence.
Collapse
Affiliation(s)
- Samira Ziaei
- City College of New York, City University of New York, New York, NY, USA.
| | | | | | | |
Collapse
|
50
|
Jochim N, Gerhard R, Just I, Pich A. Impact of clostridial glucosylating toxins on the proteome of colonic cells determined by isotope-coded protein labeling and LC-MALDI. Proteome Sci 2011; 9:48. [PMID: 21849038 PMCID: PMC3176154 DOI: 10.1186/1477-5956-9-48] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Accepted: 08/17/2011] [Indexed: 01/05/2023] Open
Abstract
Background The anaerobe Clostridium difficile produces two major virulence factors toxin A and B that inactivate Rho proteins by glucosylation of a pivotal threonine residue. Purified toxins induce reorganization of the cytoskeleton and cell death in colonic cells. Whether all toxin effects on target cells depend on catalytic glucosyltransferase activity is unclear at present. Thus, we conducted a proteome approach to compare the protein profile of target cells treated either with wild type toxin A (rTcdA wt) or with a catalytically inactive mutant toxin A (mutant rTcdA). Relative protein quantification was feasible using isotope-coded protein labeling techniques (ICPL) and mass spectrometry (LC-MALDI). Results Altogether we found a significant differential expression of thirty proteins after treatment with rTcdA wt or mutant rTcdA. Mutant rTcdA caused up-regulation of seven proteins and sixteen proteins were responsive to rTcdA wt after 5 h. Long-term effect of rTcdA wt on protein expression was the down-regulation of eleven proteins. Up- or down-regulation of several proteins was verified by western blot analysis confirming the MS results. Conclusion Our results indicate incubation time-dependent effects of the clostridial glucosylating toxin A on colonic cells. The rTcdA wt impact more cellular functions than actin cytoskeleton reorganization and apoptosis. Furthermore, these data give insight into glucosyltransferase independent effects of clostridial glucosylating toxins on target cells after short incubation time. Additionally, our data reveal pro-inflammatory and proliferative effects of mutant rTcdA after short-term incubation.
Collapse
Affiliation(s)
- Nelli Jochim
- Hannover Medical School, Institute of Toxicology, Carl-Neuberg-Str, 1, D-30625 Hannover, Germany.
| | | | | | | |
Collapse
|