scholarly journals Repression of differentiation genes by Hes transcription factors fuels neural tumour growth in Drosophila

2021 ◽  
Author(s):  
Chrysanthi Voutyraki ◽  
Alexandros Choromidis ◽  
Vasiliki Theodorou ◽  
Christina Efraimoglou ◽  
Gerasimos Anagnostopoulos ◽  
...  
Keyword(s):  
Stem Cell ◽  
Transcription Factors ◽  
Notch Signaling ◽  
Tumour Growth ◽  
Metabolic Reprogramming ◽  
Cell Physiology ◽  
Malignant Tumours ◽  
Rna Profiling ◽  
A Cell

Background: Neural stem cells (NSC) in divide asymmetrically to generate a cell that retains stem cell identity and another that is routed to differentiation. Prolonged mitotic activity of the NSCs gives rise to the plethora of neurons and glial cells that wire the brain and nerve cord. Genetic insults, such as excess of Notch signaling, perturb the normal NSC proliferation programs and trigger the formation of NSC hyperplasias, that can later progress to malignancies. Hes proteins are crucial mediators of Notch signaling and in the NSC context they act by repressing a cohort of early pro-differentiation transcription factors. Downregulation of these pro-differentiation factors makes NSC progeny cells susceptible to adopting an aberrant stem cell program. We have recently shown that Hes overexpression in Drosophila leads to NSC hyperplasias that progress to malignant tumours after allografting to adult hosts. Methods: We have combined genetic analysis, tissue allografting and transcriptomic approaches to address the role of Hes genes in NSC malignant transformation. Results: We show that the E(spl) genes are important mediators in the progression of Notch hyperplasias to malignancy, since allografts lacking the E(spl) genes grow much slower. We further present RNA profiling of Hes-induced tumours at two different stages after allografting. We find that the same cohort of differentiation-promoting transcription factors that are repressed in the primary hyperplasias continue to be downregulated after transplantation. This is accompanied by an upregulation of stress-response genes and metabolic reprogramming. Conclusions: The combination of dedifferentiation and cell physiology changes most likely drive tumour growth.

scholarly journals Crosstalk between NOTCH and AKT signaling during murine megakaryocyte lineage specification

Blood ◽  
2011 ◽  
Vol 118 (5) ◽  
pp. 1264-1273 ◽  
Author(s):  
Melanie G. Cornejo ◽  
Vinciane Mabialah ◽  
Stephen M. Sykes ◽  
Tulasi Khandan ◽  
Cristina Lo Celso ◽  
...  
Keyword(s):  
Stem Cell ◽  
Notch Signaling ◽  
Signaling Pathway ◽  
Hematopoietic Stem Cell ◽  
Stem Cell Differentiation ◽  
Notch Signaling Pathway ◽  
Developmental Pathways ◽  
Lineage Specification ◽  
Hematopoietic Stem

Abstract The NOTCH signaling pathway is implicated in a broad range of developmental processes, including cell fate decisions. However, the molecular basis for its role at the different steps of stem cell lineage commitment is unclear. We recently identified the NOTCH signaling pathway as a positive regulator of megakaryocyte lineage specification during hematopoiesis, but the developmental pathways that allow hematopoietic stem cell differentiation into the erythro-megakaryocytic lineages remain controversial. Here, we investigated the role of downstream mediators of NOTCH during megakaryopoiesis and report crosstalk between the NOTCH and PI3K/AKT pathways. We demonstrate the inhibitory role of phosphatase with tensin homolog and Forkhead Box class O factors on megakaryopoiesis in vivo. Finally, our data annotate developmental mechanisms in the hematopoietic system that enable a decision to be made either at the hematopoietic stem cell or the committed progenitor level to commit to the megakaryocyte lineage, supporting the existence of 2 distinct developmental pathways.

scholarly journals Oncogenic Metabolism Acts as a Prerequisite Step for Induction of Cancer Metastasis and Cancer Stem Cell Phenotype

2018 ◽  
Vol 2018 ◽  
pp. 1-28 ◽  
Author(s):  
Su Yeon Lee ◽  
Min Kyung Ju ◽  
Hyun Min Jeon ◽  
Yig Ji Lee ◽  
Cho Hee Kim ◽  
...  
Keyword(s):  
Stem Cell ◽  
Transcription Factors ◽  
Cancer Stem Cell ◽  
Tumor Progression ◽  
Cancer Cells ◽  
Cancer Metastasis ◽  
Metabolic Reprogramming ◽  
Glutamine Metabolism ◽  
Cell Phenotype ◽  
Mesenchymal Transition

Metastasis is a major obstacle to the efficient and successful treatment of cancer. Initiation of metastasis requires epithelial-mesenchymal transition (EMT) that is regulated by several transcription factors, including Snail and ZEB1/2. EMT is closely linked to the acquisition of cancer stem cell (CSC) properties and chemoresistance, which contribute to tumor malignancy. Tumor suppressor p53 inhibits EMT and metastasis by negatively regulating several EMT-inducing transcription factors and regulatory molecules; thus, its inhibition is crucial in EMT, invasion, metastasis, and stemness. Metabolic alterations are another hallmark of cancer. Most cancer cells are more dependent on glycolysis than on mitochondrial oxidative phosphorylation for their energy production, even in the presence of oxygen. Cancer cells enhance other oncogenic metabolic pathways, such as glutamine metabolism, pentose phosphate pathway, and the synthesis of fatty acids and cholesterol. Metabolic reprogramming in cancer is regulated by the activation of oncogenes or loss of tumor suppressors that contribute to tumor progression. Oncogenic metabolism has been recently linked closely with the induction of EMT or CSC phenotypes by the induction of several metabolic enzyme genes. In addition, several transcription factors and molecules involved in EMT or CSCs, including Snail, Dlx-2, HIF-1α, STAT3, TGF-β, Wnt, and Akt, regulate oncogenic metabolism. Moreover, p53 induces metabolic change by directly regulating several metabolic enzymes. The collective data indicate the importance of oncogenic metabolism in the regulation of EMT, cell invasion and metastasis, and adoption of the CSC phenotype, which all contribute to malignant transformation and tumor development. In this review, we highlight the oncogenic metabolism as a key regulator of EMT and CSC, which is related with tumor progression involving metastasis and chemoresistance. Targeting oncometabolism might be a promising strategy for the development of effective anticancer therapy.

scholarly journals miR-27 and miR-125 Distinctly Regulate Muscle-Enriched Transcription Factors in Cardiac and Skeletal Myocytes

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Estefania Lozano-Velasco ◽  
Jennifer Galiano-Torres ◽  
Alvaro Jodar-Garcia ◽  
Amelia E. Aranega ◽  
Diego Franco
Keyword(s):  
Transcription Factors ◽  
Cardiac Development ◽  
Protein Translation ◽  
Cell Type ◽  
Atrial Cardiomyocytes ◽  
Skeletal Myocytes ◽  
Specific Manner ◽  
A Cell ◽  
Cell Type Specific

MicroRNAs are noncoding RNAs of approximately 22–24 nucleotides which are capable of interacting with the 3′ untranslated region of coding RNAs (mRNAs), leading to mRNA degradation and/or protein translation blockage. In recent years, differential microRNA expression in distinct cardiac development and disease contexts has been widely reported, yet the role of individual microRNAs in these settings remains largely unknown. We provide herein evidence of the role of miR-27 and miR-125 regulating distinct muscle-enriched transcription factors. Overexpression of miR-27 leads to impair expression ofMstnandMyocdin HL1 atrial cardiomyocytes but not in Sol8 skeletal muscle myoblasts, while overexpression of miR-125 resulted in selective upregulation ofMef2din HL1 atrial cardiomyocytes and downregulation in Sol8 cells. Taken together our data demonstrate that a single microRNA, that is, miR-27 or miR-125, can selectively upregulate and downregulate discrete number of target mRNAs in a cell-type specific manner.

scholarly journals The Importance of Ubiquitination and Deubiquitination in Cellular Reprogramming

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Bharathi Suresh ◽  
Junwon Lee ◽  
Kye-Seong Kim ◽  
Suresh Ramakrishna
Keyword(s):  
Stem Cell ◽  
Transcription Factors ◽  
Embryonic Stem ◽  
Cellular Reprogramming ◽  
Stem Cell Maintenance ◽  
Opposite Action ◽  
Induced Pluripotent ◽  
Related Proteins ◽  
Cell Maintenance

Ubiquitination of core stem cell transcription factors can directly affect stem cell maintenance and differentiation. Ubiquitination and deubiquitination must occur in a timely and well-coordinated manner to regulate the protein turnover of several stemness related proteins, resulting in optimal embryonic stem cell maintenance and differentiation. There are two switches: an E3 ubiquitin ligase enzyme that tags ubiquitin molecules to the target proteins for proteolysis and a second enzyme, the deubiquitinating enzyme (DUBs), that performs the opposite action, thereby preventing proteolysis. In order to maintain stemness and to allow for efficient differentiation, both ubiquitination and deubiquitination molecular switches must operate properly in a balanced manner. In this review, we have summarized the importance of the ubiquitination of core stem cell transcription factors, such as Oct3/4, c-Myc, Sox2, Klf4, Nanog, and LIN28, during cellular reprogramming. Furthermore, we emphasize the role of DUBs in regulating core stem cell transcriptional factors and their function in stem cell maintenance and differentiation. We also discuss the possibility of using DUBs, along with core transcription factors, to efficiently generate induced pluripotent stem cells. Our review provides a relatively new understanding regarding the importance of ubiquitination/deubiquitination of stem cell transcription factors for efficient cellular reprogramming.

scholarly journals Megakaryopoiesis and Platelet Biology: Roles of Transcription Factors and Emerging Clinical Implications

2021 ◽  
Vol 22 (17) ◽  
pp. 9615
Author(s):  
Ji-Yoon Noh
Keyword(s):  
Bone Marrow ◽  
Stem Cell ◽  
Transcription Factors ◽  
Blood Cells ◽  
Thrombus Formation ◽  
Critical Role ◽  
Clinical Implications ◽  
Disease Development ◽  
Hematopoietic Stem

Platelets play a critical role in hemostasis and thrombus formation. Platelets are small, anucleate, and short-lived blood cells that are produced by the large, polyploid, and hematopoietic stem cell (HSC)-derived megakaryocytes in bone marrow. Approximately 3000 platelets are released from one megakaryocyte, and thus, it is important to understand the physiologically relevant mechanism of development of mature megakaryocytes. Many genes, including several key transcription factors, have been shown to be crucial for platelet biogenesis. Mutations in these genes can perturb megakaryopoiesis or thrombopoiesis, resulting in thrombocytopenia. Metabolic changes owing to inflammation, ageing, or diseases such as cancer, in which platelets play crucial roles in disease development, can also affect platelet biogenesis. In this review, I describe the characteristics of platelets and megakaryocytes in terms of their differentiation processes. The role of several critical transcription factors have been discussed to better understand the changes in platelet biogenesis that occur during disease or ageing.

scholarly journals Discovery of two GLP-1/Notch target genes that account for the role of GLP-1/Notch signaling in stem cell maintenance

2014 ◽  
Vol 111 (10) ◽  
pp. 3739-3744 ◽  
Author(s):  
Aaron M. Kershner ◽  
Heaji Shin ◽  
Tyler J. Hansen ◽  
Judith Kimble
Keyword(s):  
Stem Cell ◽  
Notch Signaling ◽  
Target Genes ◽  
Germ Line ◽  
Intercellular Signaling ◽  
Self Renewal ◽  
Stem Cell Maintenance ◽  
Per Se ◽  
Critical Link

A stem cell’s immediate microenvironment creates an essential “niche” to maintain stem cell self-renewal. Many niches and their intercellular signaling pathways are known, but for the most part, the key downstream targets of niche signaling remain elusive. Here, we report the discovery of two GLP-1/Notch target genes, lst-1 (lateral signaling target) and sygl-1 (synthetic Glp), that function redundantly to maintain germ-line stem cells (GSCs) in the nematode Caenorhabditis elegans. Whereas lst-1 and sygl-1 single mutants appear normal, lst-1 sygl-1 double mutants are phenotypically indistinguishable from glp-1/Notch mutants. Multiple lines of evidence demonstrate that GLP-1/Notch signaling activates lst-1 and sygl-1 expression in GSCs within the niche. Therefore, these two genes fully account for the role of GLP-1/Notch signaling in GSC maintenance. Importantly, lst-1 and sygl-1 are not required for GLP-1/Notch signaling per se. We conclude that lst-1 and sygl-1 forge a critical link between Notch signaling and GSC maintenance.

scholarly journals Bcl11b and combinatorial resolution of cell fate in the T-cell gene regulatory network

2017 ◽  
Vol 114 (23) ◽  
pp. 5800-5807 ◽  
Author(s):  
William J. R. Longabaugh ◽  
Weihua Zeng ◽  
Jingli A. Zhang ◽  
Hiroyuki Hosokawa ◽  
Camden S. Jansen ◽  
...  
Keyword(s):  
Transcription Factors ◽  
T Cell ◽  
Notch Signaling ◽  
Gene Regulatory Network ◽  
Cell Fate ◽  
Regulatory Network ◽  
T Cell Development ◽  
Cell Specification ◽  
Gene Regulatory

T-cell development from hematopoietic progenitors depends on multiple transcription factors, mobilized and modulated by intrathymic Notch signaling. Key aspects of T-cell specification network architecture have been illuminated through recent reports defining roles of transcription factors PU.1, GATA-3, and E2A, their interactions with Notch signaling, and roles of Runx1, TCF-1, and Hes1, providing bases for a comprehensively updated model of the T-cell specification gene regulatory network presented herein. However, the role of lineage commitment factor Bcl11b has been unclear. We use self-organizing maps on 63 RNA-seq datasets from normal and perturbed T-cell development to identify functional targets of Bcl11b during commitment and relate them to other regulomes. We show that both activation and repression target genes can be bound by Bcl11b in vivo, and that Bcl11b effects overlap with E2A-dependent effects. The newly clarified role of Bcl11b distinguishes discrete components of commitment, resolving how innate lymphoid, myeloid, and dendritic, and B-cell fate alternatives are excluded by different mechanisms.

Cancer and metabolism

2016 ◽  
pp. 119-124
Author(s):  
Cameron Snell ◽  
Kevin C. Gatter ◽  
Adrian L. Harris ◽  
Francesco Pezzella
Keyword(s):  
Tumour Growth ◽  
Glycogen Synthesis ◽  
Metabolic Reprogramming ◽  
Suppressor Activity ◽  
Metabolic Switch ◽  
Metabolic Genes ◽  
Tumour Suppressor Activity ◽  
Metabolic Transformation ◽  
The Relationship

This chapter covers the relationship between cancer and metabolism. It discusses the role of angiogenesis and metabolic reprogramming in influencing tumour growth. The transcription factors that orchestrate the metabolic switch are discussed. The chapter presents an overview of the contribution of tumour suppressors to increased glycolysis. The metabolic changes that support uncontrolled proliferation such as lactate and pH levels, hypoxia, and reactive oxygen species are discussed. The chapter also covers the contribution of metabolic genes with oncogenic or tumour suppressor activity to metabolic transformation, the upregulation of lipid biosynthesis in cancer, and glycogen synthesis in cancer. The chapter concludes with a description of the potential strategies for targeting metabolic transformation.

Concise Review: The Role of Oxygen in Hematopoietic Stem Cell Physiology

2015 ◽  
Vol 230 (9) ◽  
pp. 1999-2005 ◽  
Author(s):  
Mojca Jež ◽  
Primož Rožman ◽  
Zoran Ivanović ◽  
Tuba Bas
Keyword(s):  
Stem Cell ◽  
Hematopoietic Stem Cell ◽  
Cell Physiology ◽  
Hematopoietic Stem ◽  
Concise Review

Evolution and Cell Physiology. 4. Why invent yet another protein complex to build junctions in epithelial cells?

2013 ◽  
Vol 305 (12) ◽  
pp. C1193-C1201 ◽  
Author(s):  
André Le Bivic
Keyword(s):  
Protein Complexes ◽  
Single Layer ◽  
Tube Formation ◽  
Cell Physiology ◽  
Animal Evolution ◽  
Internal Medium ◽  
A Cell ◽  
Epithelial Layers ◽  
Crumbs Complex

The formation of the first epithelium was an essential step for animal evolution, since it has allowed coordination of the behavior of a cell layer and creation of a selective barrier between the internal medium and the outside world. The possibility of coupling the cells in a single layer has allowed morphogenetic events, such as tube formation, or gastrulation, to form more complex animal morphologies. The invention of sealed junctions between cells has allowed, on the other hand, creation of an asymmetry of nutrients or salts between the apical and the basal side of the epithelial layer. Creation of an internal medium has led to homeostasis, allowing the evolution of more complex physiological functions and the emergence of sophisticated animal shapes. During evolution, the origins of the first animals coincided with the invention of several protein complexes, including true cadherins and the polarity protein complexes. How these complexes regulate formation of the apicolateral border and the adherens junctions is still not fully understood. This review focuses on the role of these apical polarity complexes and, in particular, the Crumbs complex, which is essential for proper organization of epithelial layers from Drosophila to humans.

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