1
|
Fioretti T, Zanobio M, Raia M, Errichiello S, Izzo B, Cattaneo F, Ammendola R, Cevenini A, Esposito G. MiR-27a downregulates 14-3-3θ, RUNX1, AF4, and MLL-AF4, crucial drivers of blast transformation in t(4;11) leukemia cells. Cell Biochem Funct 2022; 40:706-717. [PMID: 35981137 PMCID: PMC9804920 DOI: 10.1002/cbf.3736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 07/01/2022] [Accepted: 07/28/2022] [Indexed: 01/09/2023]
Abstract
The chromosomal translocation t(4;11)(q21;q23), a hallmark of an aggressive form of acute lymphoblastic leukemia (ALL), encodes mixed-lineage leukemia (MLL)-AF4 oncogenic chimera that triggers aberrant transcription of genes involved in lymphocyte differentiation, including HOXA9 and MEIS1. The scaffold protein 14-3-3θ, which promotes the binding of MLL-AF4 to the HOXA9 promoter, is a target of MiR-27a, a tumor suppressor in different human leukemia cell types. We herein study the role of MiR-27a in the pathogenesis of t(4;11) ALL. Reverse transcription quantitative PCR (qPCR) reveals that MiR-27a and 14-3-3θ expression is inversely correlated in t(4;11) ALL cell lines; interestingly, MiR-27a relative expression is significantly lower in patients affected by t(4;11) ALL than in patients affected by the less severe t(12;21) leukemia. In t(4;11) leukemia cells, ectopic expression of MiR-27a decreases protein level of 14-3-3θ and of the key transcription factor RUNX1. We show for the first time that MiR-27a also targets AF4 and MLL-AF4; in agreement, MiR-27a overexpression strongly reduces AF4 and MLL-AF4 protein levels in RS4;11 cells. Consequent to AF4 and MLL-AF4 downregulation, MiR-27a overexpression negatively affects transcription of HOXA9 and MEIS1 in different t(4;11) leukemia cell lines. In agreement, we show through chromatin immunoprecipitation experiments that MiR-27a overexpression impairs the binding of MLL-AF4 to the HOXA9 promoter. Lastly, we found that MiR-27a overexpression decreases viability, proliferation, and clonogenicity of t(4;11) cells, whereas it enhances their apoptotic rate. Overall, our study identifies the first microRNAthat strikes in one hit four crucial drivers of blast transformation in t(4;11) leukemia. Therefore, MiR-27a emerges as a new promising therapeutic target for this aggressive and poorly curable form of leukemia.
Collapse
Affiliation(s)
- Tiziana Fioretti
- CEINGE Advanced Biotechnologies Franco Salvatore s.c. a r.l.NaplesItaly
| | - Mariateresa Zanobio
- Department of Molecular Medicine and Medical Biotechnology, School of MedicineUniversity of Naples Federico IINaplesItaly,Precision MedicineUniversity of Campania “Luigi Vanvitelli”Naples, Italy
| | - Maddalena Raia
- CEINGE Advanced Biotechnologies Franco Salvatore s.c. a r.l.NaplesItaly
| | - Santa Errichiello
- CEINGE Advanced Biotechnologies Franco Salvatore s.c. a r.l.NaplesItaly
| | - Barbara Izzo
- CEINGE Advanced Biotechnologies Franco Salvatore s.c. a r.l.NaplesItaly,Department of Molecular Medicine and Medical Biotechnology, School of MedicineUniversity of Naples Federico IINaplesItaly
| | - Fabio Cattaneo
- Department of Molecular Medicine and Medical Biotechnology, School of MedicineUniversity of Naples Federico IINaplesItaly
| | - Rosario Ammendola
- Department of Molecular Medicine and Medical Biotechnology, School of MedicineUniversity of Naples Federico IINaplesItaly
| | - Armando Cevenini
- CEINGE Advanced Biotechnologies Franco Salvatore s.c. a r.l.NaplesItaly,Department of Molecular Medicine and Medical Biotechnology, School of MedicineUniversity of Naples Federico IINaplesItaly
| | - Gabriella Esposito
- CEINGE Advanced Biotechnologies Franco Salvatore s.c. a r.l.NaplesItaly,Department of Molecular Medicine and Medical Biotechnology, School of MedicineUniversity of Naples Federico IINaplesItaly
| |
Collapse
|
2
|
Fioretti T, Cevenini A, Zanobio M, Raia M, Sarnataro D, Cattaneo F, Ammendola R, Esposito G. Nuclear FGFR2 Interacts with the MLL-AF4 Oncogenic Chimera and Positively Regulates HOXA9 Gene Expression in t(4;11) Leukemia Cells. Int J Mol Sci 2021; 22:ijms22094623. [PMID: 33924850 PMCID: PMC8124917 DOI: 10.3390/ijms22094623] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 04/22/2021] [Accepted: 04/26/2021] [Indexed: 12/17/2022] Open
Abstract
The chromosomal translocation t(4;11) marks an infant acute lymphoblastic leukemia associated with dismal prognosis. This rearrangement leads to the synthesis of the MLL-AF4 chimera, which exerts its oncogenic activity by upregulating transcription of genes involved in hematopoietic differentiation. Crucial for chimera’s aberrant activity is the recruitment of the AF4/ENL/P-TEFb protein complex. Interestingly, a molecular interactor of AF4 is fibroblast growth factor receptor 2 (FGFR2). We herein analyze the role of FGFR2 in the context of leukemia using t(4;11) leukemia cell lines. We revealed the interaction between MLL-AF4 and FGFR2 by immunoprecipitation, western blot, and immunofluorescence experiments; we also tested the effects of FGFR2 knockdown, FGFR2 inhibition, and FGFR2 stimulation on the expression of the main MLL-AF4 target genes, i.e., HOXA9 and MEIS1. Our results show that FGFR2 and MLL-AF4 interact in the nucleus of leukemia cells and that FGFR2 knockdown, which is associated with decreased expression of HOXA9 and MEIS1, impairs the binding of MLL-AF4 to the HOXA9 promoter. We also show that stimulation of leukemia cells with FGF2 increases nuclear level of FGFR2 in its phosphorylated form, as well as HOXA9 and MEIS1 expression. In contrast, preincubation with the ATP-mimetic inhibitor PD173074, before FGF2 stimulation, reduced FGFR2 nuclear amount and HOXA9 and MEIS1 transcript level, thereby indicating that MLL-AF4 aberrant activity depends on the nuclear availability of FGFR2. Overall, our study identifies FGFR2 as a new and promising therapeutic target in t(4;11) leukemia.
Collapse
Affiliation(s)
- Tiziana Fioretti
- CEINGE Advanced Biotechnologies s.c. a r.l., via G. Salvatore, 486, 80145 Naples, Italy; (T.F.); (A.C.); (M.R.); (D.S.)
| | - Armando Cevenini
- CEINGE Advanced Biotechnologies s.c. a r.l., via G. Salvatore, 486, 80145 Naples, Italy; (T.F.); (A.C.); (M.R.); (D.S.)
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Via S. Pansini, 5, 80131 Naples, Italy; (M.Z.); (F.C.); (R.A.)
| | - Mariateresa Zanobio
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Via S. Pansini, 5, 80131 Naples, Italy; (M.Z.); (F.C.); (R.A.)
| | - Maddalena Raia
- CEINGE Advanced Biotechnologies s.c. a r.l., via G. Salvatore, 486, 80145 Naples, Italy; (T.F.); (A.C.); (M.R.); (D.S.)
| | - Daniela Sarnataro
- CEINGE Advanced Biotechnologies s.c. a r.l., via G. Salvatore, 486, 80145 Naples, Italy; (T.F.); (A.C.); (M.R.); (D.S.)
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Via S. Pansini, 5, 80131 Naples, Italy; (M.Z.); (F.C.); (R.A.)
| | - Fabio Cattaneo
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Via S. Pansini, 5, 80131 Naples, Italy; (M.Z.); (F.C.); (R.A.)
| | - Rosario Ammendola
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Via S. Pansini, 5, 80131 Naples, Italy; (M.Z.); (F.C.); (R.A.)
| | - Gabriella Esposito
- CEINGE Advanced Biotechnologies s.c. a r.l., via G. Salvatore, 486, 80145 Naples, Italy; (T.F.); (A.C.); (M.R.); (D.S.)
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Via S. Pansini, 5, 80131 Naples, Italy; (M.Z.); (F.C.); (R.A.)
- Correspondence: ; Tel.: +30-0817463146
| |
Collapse
|
3
|
Crosstalk between 14-3-3θ and AF4 enhances MLL-AF4 activity and promotes leukemia cell proliferation. Cell Oncol (Dordr) 2019; 42:829-845. [PMID: 31493143 DOI: 10.1007/s13402-019-00468-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/19/2019] [Indexed: 01/14/2023] Open
Abstract
PURPOSE The t(4;11)(q21;q23) translocation characterizes a form of acute lymphoblastic leukemia with a poor prognosis. It results in a fusion gene encoding a chimeric transcription factor, MLL-AF4, that deregulates gene expression through a variety of still controversial mechanisms. To provide new insights into these mechanisms, we examined the interaction between AF4, the most common MLL fusion partner, and the scaffold protein 14-3-3θ, in the context of t(4;11)-positive leukemia. METHODS Protein-protein interactions were analyzed using immunoprecipitation and in vitro binding assays, and by fluorescence microscopy in t(4;11)-positive RS4;11 and MV4-11 leukemia cells and in HEK293 cells. Protein and mRNA expression levels were determined by Western blotting and RT-qPCR, respectively. A 5-bromo-2'-deoxyuridine assay and an annexin V/propidium iodide assay were used to assess proliferation and apoptosis rates, respectively, in t(4;11)-positive and control cells. Chromatin immunoprecipitation was performed to assess binding of 14-3-3θ and AF4 to a specific promoter element. RESULTS We found that AF4 and 14-3-3θ are nuclear interactors, that 14-3-3θ binds Ser588 of AF4 and that 14-3-3θ forms a complex with MLL-AF4. In addition, we found that in t(4;11)-positive cells, 14-3-3θ knockdown decreased the expression of MLL-AF4 target genes, induced apoptosis and hampered cell proliferation. Moreover, we found that 14-3-3θ knockdown impaired the recruitment of AF4, but not of MLL-AF4, to target chromatin. Overall, our data indicate that the activity of the chimeric transcription factor MLL-AF4 depends on the cellular availability of 14-3-3θ, which triggers the transactivating function and subsequent degradation of AF4. CONCLUSIONS From our data we conclude that the scaffold protein 14-3-3θ enhances the aberrant activity of the chimeric transcription factor MLL-AF4 and, therefore, represents a new player in the molecular pathogenesis of t(4;11)-positive leukemia and a new promising therapeutic target.
Collapse
|
4
|
Swapna LS, Molinaro AM, Lindsay-Mosher N, Pearson BJ, Parkinson J. Comparative transcriptomic analyses and single-cell RNA sequencing of the freshwater planarian Schmidtea mediterranea identify major cell types and pathway conservation. Genome Biol 2018; 19:124. [PMID: 30143032 PMCID: PMC6109357 DOI: 10.1186/s13059-018-1498-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 08/01/2018] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND In the Lophotrochozoa/Spiralia superphylum, few organisms have as high a capacity for rapid testing of gene function and single-cell transcriptomics as the freshwater planaria. The species Schmidtea mediterranea in particular has become a powerful model to use in studying adult stem cell biology and mechanisms of regeneration. Despite this, systematic attempts to define gene complements and their annotations are lacking, restricting comparative analyses that detail the conservation of biochemical pathways and identify lineage-specific innovations. RESULTS In this study we compare several transcriptomes and define a robust set of 35,232 transcripts. From this, we perform systematic functional annotations and undertake a genome-scale metabolic reconstruction for S. mediterranea. Cross-species comparisons of gene content identify conserved, lineage-specific, and expanded gene families, which may contribute to the regenerative properties of planarians. In particular, we find that the TRAF gene family has been greatly expanded in planarians. We further provide a single-cell RNA sequencing analysis of 2000 cells, revealing both known and novel cell types defined by unique signatures of gene expression. Among these are a novel mesenchymal cell population as well as a cell type involved in eye regeneration. Integration of our metabolic reconstruction further reveals the extent to which given cell types have adapted energy and nucleotide biosynthetic pathways to support their specialized roles. CONCLUSIONS In general, S. mediterranea displays a high level of gene and pathway conservation compared with other model systems, rendering it a viable model to study the roles of these pathways in stem cell biology and regeneration.
Collapse
Affiliation(s)
| | - Alyssa M Molinaro
- Hospital for Sick Children, Toronto, ON, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Nicole Lindsay-Mosher
- Hospital for Sick Children, Toronto, ON, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Bret J Pearson
- Hospital for Sick Children, Toronto, ON, Canada. .,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada. .,Ontario Institute for Cancer Research, Toronto, ON, Canada.
| | - John Parkinson
- Hospital for Sick Children, Toronto, ON, Canada. .,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada. .,Department of Biochemistry, University of Toronto, Toronto, ON, Canada.
| |
Collapse
|
5
|
Franco LC, Morales F, Boffo S, Giordano A. CDK9: A key player in cancer and other diseases. J Cell Biochem 2017; 119:1273-1284. [PMID: 28722178 DOI: 10.1002/jcb.26293] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 07/18/2017] [Indexed: 02/06/2023]
Abstract
Cyclin-Dependent Kinase 9 (CDK9) is part of a functional diverse group of enzymes responsible for cell cycle control and progression. It associates mainly with Cyclin T1 and forms the Positive Transcription Elongation Factor b (p-TEFb) complex responsible for regulation of transcription elongation and mRNA maturation. Recent studies have highlighted the importance of CDK9 in many relevant pathologic processes, like cancer, cardiovascular diseases, and viral replication. Herein we provide an overview of the different pathways in which CDK9 is directly and indirectly involved.
Collapse
Affiliation(s)
- Lia Carolina Franco
- Escuela de Medicina, Universidad de las Americas (UDLA), Quito, Ecuador.,Sbarro Institute for Cancer Research and Molecular Medicine, Department of Biology, College of Science and Technology, Temple University, PA, Pennsylvania
| | - Fátima Morales
- Sbarro Institute for Cancer Research and Molecular Medicine, Department of Biology, College of Science and Technology, Temple University, PA, Pennsylvania.,Departamento de Química Orgánica, Universidad de Murcia, Murcia, Spain
| | - Silvia Boffo
- Sbarro Institute for Cancer Research and Molecular Medicine, Department of Biology, College of Science and Technology, Temple University, PA, Pennsylvania
| | - Antonio Giordano
- Sbarro Institute for Cancer Research and Molecular Medicine, Department of Biology, College of Science and Technology, Temple University, PA, Pennsylvania.,Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
| |
Collapse
|
6
|
Kuzmina A, Krasnopolsky S, Taube R. Super elongation complex promotes early HIV transcription and its function is modulated by P-TEFb. Transcription 2017; 8:133-149. [PMID: 28340332 DOI: 10.1080/21541264.2017.1295831] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Early work on the control of transcription of the human immunodeficiency virus (HIV) laid the foundation for our current knowledge of how RNA Polymerase II is released from promoter-proximal pausing sites and transcription elongation is enhanced. The viral Tat activator recruits Positive Transcription Elongation Factor b (P-TEFb) and Super Elongation Complex (SEC) that jointly drive transcription elongation. While substantial progress in understanding the role of SEC in HIV gene transcription elongation has been obtained, defining of the mechanisms that govern SEC functions is still limited, and the role of SEC in controlling HIV transcription in the absence of Tat is less clear. Here we revisit the contribution of SEC in early steps of HIV gene transcription. In the absence of Tat, the AF4/FMR2 Family member 4 (AFF4) of SEC efficiently activates HIV transcription, while gene activation by its homolog AFF1 is substantially lower. Differential recruitment to the HIV promoter and association with Human Polymerase-Associated Factor complex (PAFc) play key role in this functional distinction between AFF4 and AFF1. Moreover, while depletion of cyclin T1 expression has subtle effects on HIV gene transcription in the absence of Tat, knockout (KO) of AFF1, AFF4, or both proteins slightly repress this early step of viral transcription. Upon Tat expression, HIV transcription reaches optimal levels despite KO of AFF1 or AFF4 expression. However, double AFF1/AFF4 KO completely diminishes Tat trans-activation. Significantly, our results show that P-TEFb phosphorylates AFF4 and modulates SEC assembly, AFF1/4 dimerization and recruitment to the viral promoter. We conclude that SEC promotes both early steps of HIV transcription in the absence of Tat, as well as elongation of transcription, when Tat is expressed. Significantly, SEC functions are modulated by P-TEFb.
Collapse
Affiliation(s)
- Alona Kuzmina
- a The Shraga Segal Department of Microbiology Immunology and Genetics Faculty of Health Sciences , Ben-Gurion University of the Negev , Israel
| | - Simona Krasnopolsky
- a The Shraga Segal Department of Microbiology Immunology and Genetics Faculty of Health Sciences , Ben-Gurion University of the Negev , Israel
| | - Ran Taube
- a The Shraga Segal Department of Microbiology Immunology and Genetics Faculty of Health Sciences , Ben-Gurion University of the Negev , Israel
| |
Collapse
|
7
|
Melko M, Nguyen LS, Shaw M, Jolly L, Bardoni B, Gecz J. Loss of FMR2 further emphasizes the link between deregulation of immediate early response genes FOS and JUN and intellectual disability. Hum Mol Genet 2013; 22:2984-91. [PMID: 23562910 DOI: 10.1093/hmg/ddt155] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Loss of FMR2 causes Fragile X E (FRAXE) site-associated intellectual disability (ID). FMR2 regulates transcription, promotes alternative splicing with preference for G-quartet structure harbouring exons and is localized to the nuclear speckles. In primary skin fibroblasts from FRAXE patients (n = 8), we found a significant reduction in the number, but a significant increase in the size, of nuclear speckles, when compared with the controls (n = 4). Since nuclear speckles are enriched with factors involved in pre-mRNA processing, we explored the consequence of these defects and the loss of FMR2 on the transcriptome. We performed whole genome expression profiling using total RNA extracted from these cell lines and found 27 genes significantly deregulated by at least 2-fold at P < 0.05 in the patients. Among these genes, FOS was significantly upregulated and was further investigated due to its established role in neuronal cell function. We showed that (i) 30% depletion of Fmr2 in mouse primary cortical neurons led to a 2-fold increase in Fos expression, (ii) overexpression of FMR2 significantly decreased FOS promoter activity in luciferase assays, and (iii) as FOS promoter contains a serum response element, we found that not FOS, but JUN, which encodes for a protein that forms a transcriptional activator complex with FOS, was significantly upregulated in the patients' cell lines upon mitogen stimulation. These results suggest that FMR2 is an upstream regulator of FOS and JUN, and further link deregulation of the immediate early response genes to the pathology of ID- and FRAXE-associated ID in particular.
Collapse
Affiliation(s)
- Mireille Melko
- Institut de Pharmacologie Moléculaire et Cellulaire, CNRS UMR 7275, 660 Route des Lucioles, F-06560 Valbonne, France
| | | | | | | | | | | |
Collapse
|
8
|
Ribavirin-induced intracellular GTP depletion activates transcription elongation in coagulation factor VII gene expression. Biochem J 2013; 449:231-9. [PMID: 23050902 DOI: 10.1042/bj20121286] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Coagulation FVII (Factor VII) is a vitamin K-dependent glycoprotein synthesized in hepatocytes. It was reported previously that FVII gene (F7) expression was up-regulated by ribavirin treatment in hepatitis C virus-infected haemophilia patients; however, its precise mechanism is still unknown. In the present study, we investigated the molecular mechanism of ribavirin-induced up-regulation of F7 expression in HepG2 (human hepatoma cell line). We found that intracellular GTP depletion by ribavirin as well as other IMPDH (inosine-5'-monophosphate dehydrogenase) inhibitors, such as mycophenolic acid and 6-mercaptopurine, up-regulated F7 expression. FVII mRNA transcription was mainly enhanced by accelerated transcription elongation, which was mediated by the P-TEFb (positive-transcription elongation factor b) complex, rather than by promoter activation. Ribavirin unregulated ELL (eleven-nineteen lysine-rich leukaemia) 3 mRNA expression before F7 up-regulation. We observed that ribavirin enhanced ELL3 recruitment to F7, whereas knockdown of ELL3 diminished ribavirin-induced FVII mRNA up-regulation. Ribavirin also enhanced recruitment of CDK9 (cyclin-dependent kinase 9) and AFF4 to F7. These data suggest that ribavirin-induced intracellular GTP depletion recruits a super elongation complex containing P-TEFb, AFF4 and ELL3, to F7, and modulates FVII mRNA transcription elongation. Collectively, we have elucidated a basal mechanism for ribavirin-induced FVII mRNA up-regulation by acceleration of transcription elongation, which may be crucial in understanding its pleiotropic functions in vivo.
Collapse
|