51
|
Corallino S, Malabarba MG, Zobel M, Di Fiore PP, Scita G. Epithelial-to-Mesenchymal Plasticity Harnesses Endocytic Circuitries. Front Oncol 2015; 5:45. [PMID: 25767773 PMCID: PMC4341543 DOI: 10.3389/fonc.2015.00045] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 02/09/2015] [Indexed: 02/01/2023] Open
Abstract
The ability of cells to alter their phenotypic and morphological characteristics, known as cellular plasticity, is critical in normal embryonic development and adult tissue repair and contributes to the pathogenesis of diseases, such as organ fibrosis and cancer. The epithelial-to-mesenchymal transition (EMT) is a type of cellular plasticity. This transition involves genetic and epigenetic changes as well as alterations in protein expression and post-translational modifications. These changes result in reduced cell-cell adhesion, enhanced cell adhesion to the extracellular matrix, and altered organization of the cytoskeleton and of cell polarity. Among these modifications, loss of cell polarity represents the nearly invariable, distinguishing feature of EMT that frequently precedes the other traits or might even occur in their absence. EMT transforms cell morphology and physiology, and hence cell identity, from one typical of cells that form a tight barrier, like epithelial and endothelial cells, to one characterized by a highly motile mesenchymal phenotype. Time-resolved proteomic and phosphoproteomic analyses of cells undergoing EMT recently identified thousands of changes in proteins involved in many cellular processes, including cell proliferation and motility, DNA repair, and - unexpectedly - membrane trafficking (1). These results have highlighted a picture of great complexity. First, the EMT transition is not an all-or-none response but rather a gradual process that develops over time. Second, EMT events are highly dynamic and frequently reversible, involving both cell-autonomous and non-autonomous mechanisms. The net results is that EMT generates populations of mixed cells, with partial or full phenotypes, possibly accounting (at least in part) for the physiological as well as pathological cellular heterogeneity of some tissues. Endocytic circuitries have emerged as complex connectivity infrastructures for numerous cellular networks required for the execution of different biological processes, with a primary role in the control of polarized functions. Thus, they may be relevant for controlling EMT or certain aspects of it. Here, by discussing a few paradigmatic cases, we will outline how endocytosis may be harnessed by the EMT process to promote dynamic changes in cellular identity, and to increase cellular flexibility and adaptation to micro-environmental cues, ultimately impacting on physiological and pathological processes, first and foremost cancer progression.
Collapse
Affiliation(s)
| | - Maria Grazia Malabarba
- Fondazione Istituto FIRC di Oncologia Molecolare (IFOM) , Milan , Italy ; Dipartimento di Scienze della Salute, Università degli Studi di Milano , Milan , Italy
| | - Martina Zobel
- Fondazione Istituto FIRC di Oncologia Molecolare (IFOM) , Milan , Italy
| | - Pier Paolo Di Fiore
- Fondazione Istituto FIRC di Oncologia Molecolare (IFOM) , Milan , Italy ; Dipartimento di Scienze della Salute, Università degli Studi di Milano , Milan , Italy ; Dipartimento di Oncologia Sperimentale, Istituto Europeo di Oncologia , Milan , Italy
| | - Giorgio Scita
- Fondazione Istituto FIRC di Oncologia Molecolare (IFOM) , Milan , Italy ; Dipartimento di Scienze della Salute, Università degli Studi di Milano , Milan , Italy
| |
Collapse
|
52
|
Azzarelli R, Guillemot F, Pacary E. Function and regulation of Rnd proteins in cortical projection neuron migration. Front Neurosci 2015; 9:19. [PMID: 25705175 PMCID: PMC4319381 DOI: 10.3389/fnins.2015.00019] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 01/13/2015] [Indexed: 01/08/2023] Open
Abstract
The mammalian cerebral cortex contains a high variety of neuronal subtypes that acquire precise spatial locations and form long or short-range connections to establish functional neuronal circuits. During embryonic development, cortical projection neurons are generated in the areas lining the lateral ventricles and they subsequently undergo radial migration to reach the position of their final maturation within the cortical plate. The control of the neuroblast migratory behavior and the coordination of the migration process with other neurogenic events such as cell cycle exit, differentiation and final maturation are crucial to normal brain development. Among the key regulators of cortical neuron migration, the small GTP binding proteins of the Rho family and the atypical Rnd members play important roles in integrating intracellular signaling pathways into changes in cytoskeletal dynamics and motility behavior. Here we review the role of Rnd proteins during cortical neuronal migration and we discuss both the upstream mechanisms that regulate Rnd protein activity and the downstream molecular pathways that mediate Rnd effects on cell cytoskeleton.
Collapse
Affiliation(s)
- Roberta Azzarelli
- Cambridge Department of Oncology, Hutchison/MRC Research Centre, University of Cambridge Cambridge, UK
| | - François Guillemot
- Division of Molecular Neurobiology, MRC National Institute for Medical Research London, UK
| | - Emilie Pacary
- Institut National de la Santé et de la Recherche Médicale U862, Neurocentre Magendie Bordeaux, France ; Université de Bordeaux Bordeaux, France
| |
Collapse
|
53
|
Xuan Y, Yang H, Zhao L, Lau WB, Lau B, Ren N, Hu Y, Yi T, Zhao X, Zhou S, Wei Y. MicroRNAs in colorectal cancer: small molecules with big functions. Cancer Lett 2014; 360:89-105. [PMID: 25524553 DOI: 10.1016/j.canlet.2014.11.051] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Revised: 11/19/2014] [Accepted: 11/20/2014] [Indexed: 02/05/2023]
Abstract
Colorectal cancer (CRC) is the third most lethal malignancy, with pathogenesis intricately dependent upon microRNAs (miRNAs). miRNAs are short, non-protein coding RNAs, targeting the 3'-untranslated regions (3'-UTR) of certain mRNAs. They usually serve as tumor suppressors or oncogenes, and participate in tumor phenotype maintenance. Therefore, miRNAs consequently regulate CRC carcinogenesis and other biological functions, including apoptosis, development, angiogenesis, migration, and proliferation. Due to its differential expression and distinct stability, miRNAs are regarded as molecular biomarkers (for diagnosis/prognosis) and therapeutic targets for CRC. Recently, a remarkable number of miRNAs have been discovered with implications via incompletely understood mechanisms in CRC. As further study of relevant miRNAs continues, it is hopeful that novel miRNA-based therapeutic strategies may be available for CRC patients in the future.
Collapse
Affiliation(s)
- Yu Xuan
- Department of Gynecology and Obstetrics, Key Laboratory of Obstetrics & Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, West China Second Hospital, Sichuan University, Chengdu 610041, China; The State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Huiliang Yang
- The State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Linjie Zhao
- The State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Wayne Bond Lau
- Department of Emergency Medicine, Thomas Jefferson University Hospital, USA
| | - Bonnie Lau
- Department of Surgery, Emergency Medicine, Kaiser Santa Clara Medial Center, Affiliate of Stanford University, USA
| | - Ning Ren
- College of Biological Sciences, Sichuan University, Chengdu 610041, China
| | - Yuehong Hu
- Department of Gynecology and Obstetrics, Key Laboratory of Obstetrics & Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, West China Second Hospital, Sichuan University, Chengdu 610041, China
| | - Tao Yi
- Department of Gynecology and Obstetrics, Key Laboratory of Obstetrics & Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, West China Second Hospital, Sichuan University, Chengdu 610041, China
| | - Xia Zhao
- Department of Gynecology and Obstetrics, Key Laboratory of Obstetrics & Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, West China Second Hospital, Sichuan University, Chengdu 610041, China
| | - Shengtao Zhou
- Department of Gynecology and Obstetrics, Key Laboratory of Obstetrics & Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, West China Second Hospital, Sichuan University, Chengdu 610041, China.
| | - Yuquan Wei
- The State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| |
Collapse
|
54
|
Gómez O, Ballester-Lurbe B, Guasch RM, Pérez-Roger I, García-Roselló E, Terrado J. Analysis of RhoE expression in the testis, epididymis and ductus deferens, and the effects of its deficiency in mice. J Anat 2014; 225:583-90. [PMID: 25270035 DOI: 10.1111/joa.12241] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/02/2014] [Indexed: 12/12/2022] Open
Abstract
Rho proteins are a large family of GTPases involved in the control of actin cytoskeleton dynamics, proliferation and survival. Rnd1, Rnd2 and RhoE/Rnd3 form a subfamily of Rho proteins characterized by being constitutively active. The role of these proteins has been studied during the last years in several systems; however, little is known about their expression and functions in the reproductive organs. In this work we analysed the localization and the effect of RhoE deficiency in the testes using mice lacking RhoE expression (RhoE gt/gt), and our research shows some unexpected and relevant results. First, we have observed that RhoE is only expressed in Leydig cells within the testicular parenchyma and it is absent of seminiferous tubules. In addition, RhoE is expressed in the excurrent ducts of the testis, including the ductuli efferentes, epididymis and ductus deferens. Moreover, the testes of postnatal 15-day-old RhoE null mice are smaller, both in absolute values and in relation to the body weight. Furthermore, the dimensions of their seminiferous tubules are also reduced compared with wild-types. In order to study the role of RhoE in the adult, we analysed heterozygous animals as RhoE null mice die early postnatally. Our results show that the testes of adult RhoE heterozygous mice are also smaller than those of the wild-types, with a 17% decrease in the ratio testis weight/body weight. In addition, their seminiferous tubules have reduced tubular diameter (12%) and a thinner epithelial wall (33%) that appears disorganized and with a swollen lumen. Finally, and probably as a consequence of those alterations, the sperm concentration of heterozygous animals was found to be lower than in the wild-types. These results indicate that accurate levels of RhoE in the testes are necessary for a correct development and function of male gonads, and suggest novel and unexpected roles of Rnd GTPases in the reproductive physiology.
Collapse
Affiliation(s)
- Olga Gómez
- Departamento de Medicina y Cirugía Animal, Facultad de Veterinaria, Universidad CEU Cardenal Herrera, Alfara del Patriarca, Valencia, Spain
| | | | | | | | | | | |
Collapse
|
55
|
Shen L, Qin K, Wang D, Zhang Y, Bai N, Yang S, Luo Y, Xiang R, Tan X. Overexpression of Oct4 suppresses the metastatic potential of breast cancer cells via Rnd1 downregulation. Biochim Biophys Acta Mol Basis Dis 2014; 1842:2087-95. [PMID: 25068817 DOI: 10.1016/j.bbadis.2014.07.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Revised: 07/07/2014] [Accepted: 07/21/2014] [Indexed: 02/05/2023]
Abstract
Although Oct4 is known as a critical transcription factor involved in maintaining "stemness", its role in tumor metastasis is still controversial. Herein, we overexpressed and silenced Oct4 expression in two breast cancer cell lines, MDA-MB-231 and 4T1, separately. Our data showed that ectopic overexpression of Oct4 suppressed cell migration and invasion in vitro and the formation of metastatic lung nodules in vivo. Conversely, Oct4 downregulation increased the metastatic potential of breast cancer cells both in vitro and in vivo. Furthermore, we identified Rnd1 as the downstream target of Oct4 by ribonucleic acid sequencing (RNA-seq) analysis, which was significantly downregulated upon Oct4 overexpression. Chromatin immunoprecipitation assays revealed the binding of Oct4 to the promoter region of Rnd1 by ectopic overexpression of Oct4. Dual luciferase assays indicated that Oct4 overexpression suppressed transcriptional activity of the Rnd1 promoter. Moreover, overexpression of Rnd1 partially rescued the inhibitory effects of Oct4 on the migration and invasion of breast cancer cells. Overexpression of Rnd1 counteracted the influence of Oct4 on the formation of cell adhesion and lamellipodia, which implied a potential underlying mechanism involving Rnd1. In addition, we also found that overexpression of Oct4 led to an elevation of E-cadherin expression, even in 4T1 cells that possess a relatively high basal level of E-cadherin. Rnd1 overexpression impaired the promoting effects of Oct4 on E-cadherin expression in MDA-MB-231 cells. These results suggest that Oct4 affects the metastatic potential of breast cancer cells through Rnd1-mediated effects that influence cell motility and E-cadherin expression.
Collapse
Affiliation(s)
- Long Shen
- Department of Pathology, Medical School of Nankai University, Tianjin 300071, China
| | - Kunhua Qin
- Department of Immunology, Medical School of Nankai University, Tianjin 300071, China
| | - Dekun Wang
- Department of Pathology, Medical School of Nankai University, Tianjin 300071, China
| | - Yan Zhang
- Department of Immunology, Medical School of Nankai University, Tianjin 300071, China
| | - Nan Bai
- Department of Immunology, Medical School of Nankai University, Tianjin 300071, China
| | - Shengyong Yang
- West China Hospital, Molecular Medicine Research Centre, State Key Lab Biotherapy, Sichuan University, Chengdu 610064, China
| | - Yunping Luo
- Department of Immunology, Beijing Union Medical School, Beijing 100010, China
| | - Rong Xiang
- Department of Immunology, Medical School of Nankai University, Tianjin 300071, China
| | - Xiaoyue Tan
- Department of Pathology, Medical School of Nankai University, Tianjin 300071, China.
| |
Collapse
|
56
|
RhoE deficiency alters postnatal subventricular zone development and the number of calbindin-expressing neurons in the olfactory bulb of mouse. Brain Struct Funct 2014; 220:3113-30. [DOI: 10.1007/s00429-014-0846-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Accepted: 07/04/2014] [Indexed: 10/25/2022]
|
57
|
Sadok A, Marshall CJ. Rho GTPases: masters of cell migration. Small GTPases 2014; 5:e29710. [PMID: 24978113 PMCID: PMC4107589 DOI: 10.4161/sgtp.29710] [Citation(s) in RCA: 158] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Revised: 06/06/2014] [Accepted: 06/24/2014] [Indexed: 12/17/2022] Open
Abstract
Since their discovery in the late eighties, the role of Rho GTPases in the regulation of cell migration has been extensively studied and has mainly focused on the hallmark family members Rho, Rac, and Cdc42. Recent technological advances in cell biology, such as Rho-family GTPase activity biosensors, studies in 3D, and unbiased RNAi-based screens, have revealed an increasingly complex role for Rho GTPases during cell migration, with many inter-connected functions and a strong dependency on the physical and chemical properties of the surrounding environment. This review aims to give an overview of recent studies on the role of Rho-family GTPase members in the modulation of cell migration in different environments, and discuss future directions.
Collapse
Affiliation(s)
- Amine Sadok
- The Institute of Cancer Research; Division of Cancer Biology; London, UK
| | - Chris J Marshall
- The Institute of Cancer Research; Division of Cancer Biology; London, UK
| |
Collapse
|
58
|
Roet KCD, Verhaagen J. Understanding the neural repair-promoting properties of olfactory ensheathing cells. Exp Neurol 2014; 261:594-609. [PMID: 24842489 DOI: 10.1016/j.expneurol.2014.05.007] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 05/02/2014] [Accepted: 05/06/2014] [Indexed: 12/13/2022]
Abstract
Olfactory ensheathing glial cells (OECs) are a specialized type of glia that form a continuously aligned cellular pathway that actively supports unprecedented regeneration of primary olfactory axons from the periphery into the central nervous system. Implantation of OECs stimulates neural repair in experimental models of spinal cord, brain and peripheral nerve injury and delays disease progression in animal models for neurodegenerative diseases like amyotrophic lateral sclerosis. OECs implanted in the injured spinal cord display a plethora of pro-regenerative effects; they promote axonal regeneration, reorganize the glial scar, remyelinate axons, stimulate blood vessel formation, have phagocytic properties and modulate the immune response. Recently genome wide transcriptional profiling and proteomics analysis combined with classical or larger scale "medium-throughput" bioassays have provided novel insights into the molecular mechanism that endow OECs with their pro-regenerative properties. Here we review these studies and show that the gaps that existed in our understanding of the molecular basis of the reparative properties of OECs are narrowing. OECs express functionally connected sets of genes that can be linked to at least 10 distinct processes directly relevant to neural repair. The data indicate that OECs exhibit a range of synergistic cellular activities, including active and passive stimulation of axon regeneration (by secretion of growth factors, axon guidance molecules and basement membrane components) and critical aspects of tissue repair (by structural remodeling and support, modulation of the immune system, enhancement of neurotrophic and antigenic stimuli and by metabolizing toxic macromolecules). Future experimentation will have to further explore the newly acquired knowledge to enhance the therapeutic potential of OECs.
Collapse
Affiliation(s)
- Kasper C D Roet
- Department of Neuroregeneration, Netherlands Institute for Neuroscience, An Institute of the Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, 1105BA Amsterdam, The Netherlands.
| | - Joost Verhaagen
- Department of Neuroregeneration, Netherlands Institute for Neuroscience, An Institute of the Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, 1105BA Amsterdam, The Netherlands; Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University, Boelelaan 1085, Amsterdam 1081HV, The Netherlands.
| |
Collapse
|
59
|
STI1 antagonizes cytoskeleton collapse mediated by small GTPase Rnd1 and regulates neurite growth. Exp Cell Res 2014; 324:84-91. [PMID: 24690281 DOI: 10.1016/j.yexcr.2014.03.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 03/19/2014] [Accepted: 03/22/2014] [Indexed: 01/10/2023]
Abstract
Rnd proteins comprise a branch of the Rho family of small GTP-binding proteins, which have been implicated in rearrangements of the actin cytoskeleton and microtubule dynamics. Particularly in the nervous system, Rnd family proteins regulate neurite formation, dendrite development and axonal branching. A secreted form of the co-chaperone Stress-Inducible Protein 1 (STI1) has been described as a prion protein partner that is involved in several processes of the nervous system, such as neurite outgrowth, neuroprotection, astrocyte development, and the self-renewal of neural progenitor cells. We show that cytoplasmic STI1 directly interacts with the GTPase Rnd1. This interaction is specific for the Rnd1 member of the Rnd family. In the COS collapse assay, overexpression of STI1 prevents Rnd1-plexin-A1-mediated cytoskeleton retraction. In PC-12 cells, overexpression of STI1 enhances neurite outgrowth in cellular processes initially established by Rnd1. Therefore, we propose that STI1 participates in Rnd1-induced signal transduction pathways that are involved in the dynamics of the actin cytoskeleton.
Collapse
|
60
|
Abstract
Rho GTPases are a family of small GTPases, which play an important role in the regulation of the actin cytoskeleton. Not surprisingly, Rho GTPases are crucial for cell migration and therefore highly important for cancer cell invasion and the formation of metastases. In addition, Rho GTPases are involved in growth and survival of tumor cells, in the interaction of tumor cells with their environment, and they are vital for the cancer supporting functions of the tumor stroma. Recent research has significantly improved our understanding of the regulation of Rho GTPase activity, the specificity of Rho GTPases, and their function in tumor stem cells and tumor stroma. This review summarizes these novel findings and tries to define challenging questions for future research.
Collapse
Affiliation(s)
- Hui Li
- University of Copenhagen, BRIC, BMI, 2200, Copenhagen, Denmark
| | | | | | | |
Collapse
|
61
|
Fu Y, Liu X, Zhou N, Du L, Sun Y, Zhang X, Ge Y. MicroRNA-200b Stimulates Tumour Growth in TGFBR2-Null Colorectal Cancers by Negatively Regulating p27/kip1. J Cell Physiol 2014; 229:772-82. [DOI: 10.1002/jcp.24497] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 10/16/2013] [Indexed: 12/25/2022]
Affiliation(s)
- Yuxuan Fu
- Department of Physiology; Nanjing Medical University; Nanjing People's Republic of China
| | - Xianghua Liu
- Department of Biochemistry and Molecular Biology; Nanjing Medical University; Nanjing People's Republic of China
| | - Ningtian Zhou
- Department of Cardiology; First Affiliated Hospital of Nanjing Medical University; Nanjing People's Republic of China
| | - Lijian Du
- The Laboratory Center for Basic Medical Sciences; Nanjing Medical University; Nanjing People's Republic of China
| | - Yu Sun
- Department of Orthopedics; Clinical Medical College of Yangzhou University; Subei People's Hospital of Jiangsu Province; Yangzhou People's Republic of China
| | - Xiang Zhang
- Department of Physiology; Nanjing Medical University; Nanjing People's Republic of China
| | - Yingbin Ge
- Department of Physiology; Nanjing Medical University; Nanjing People's Republic of China
| |
Collapse
|
62
|
Linch M, Riou P, Claus J, Cameron AJ, de Naurois J, Larijani B, Ng T, McDonald NQ, Parker PJ. Functional implications of assigned, assumed and assembled PKC structures. Biochem Soc Trans 2014; 42:35-41. [PMID: 24450624 DOI: 10.1042/bst20130192] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2024]
Abstract
The empirical derivation of PKC (protein kinase C) domain structures and those modelled by homology or imputed from protein behaviour have been extraordinarily valuable both in the elucidation of PKC pathway mechanisms and in the general lessons that extrapolate to other signalling pathways. For PKC family members, there are many domain/subdomain structures and models, covering all of the known domains, variably present in this family of protein serine/threonine kinases (C1, C2, PB1, HR1, kinase domains). In addition to these structures, there are a limited number of complexes defined, including the structure of the PKCε V3-14-3-3 complex. In the context of structure-driven insights into PKC pathways, there are several broadly applicable principles and mechanisms relevant to the operation of and intervention in signalling pathways. These principles have an impact in unexpected ways, from the regulation of membrane targeting, through strategies for pharmacological intervention, to biomarkers.
Collapse
Affiliation(s)
- Mark Linch
- *Protein Phosphorylation Laboratory, London Research Institute, Cancer Research UK, 44 Lincoln's Inn Fields, London WC2A 3LY, U.K
| | - Philippe Riou
- *Protein Phosphorylation Laboratory, London Research Institute, Cancer Research UK, 44 Lincoln's Inn Fields, London WC2A 3LY, U.K
| | - Jeroen Claus
- *Protein Phosphorylation Laboratory, London Research Institute, Cancer Research UK, 44 Lincoln's Inn Fields, London WC2A 3LY, U.K
| | | | - Julien de Naurois
- ‡Cell Biophysics Laboratory, London Research Institute, Cancer Research UK, 44 Lincoln's Inn Fields, London WC2A 3LY, U.K
| | - Banafshe Larijani
- ‡Cell Biophysics Laboratory, London Research Institute, Cancer Research UK, 44 Lincoln's Inn Fields, London WC2A 3LY, U.K
| | - Tony Ng
- §Division of Cancer Studies, King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, U.K
| | | | | |
Collapse
|
63
|
Freitag SI, Wong J, Young PG. Genetic and physical interaction of Ssp1 CaMKK and Rad24 14-3-3 during low pH and osmotic stress in fission yeast. Open Biol 2014; 4:130127. [PMID: 24451546 PMCID: PMC3909272 DOI: 10.1098/rsob.130127] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The Ssp1 calmodulin kinase kinase (CaMKK) is necessary for stress-induced re-organization of the actin cytoskeleton and initiation of growth at the new cell end following division in Schizosaccharomyces pombe. In addition, it regulates AMP-activated kinase and functions in low glucose tolerance. ssp1− cells undergo mitotic delay at elevated temperatures and G2 arrest in the presence of additional stressors. Following hyperosmotic stress, Ssp1-GFP forms transient foci which accumulate at the cell membrane and form a band around the cell circumference, but not co-localizing with actin patches. Hyperosmolarity-induced localization to the cell membrane occurs concomitantly with a reduction of its interaction with the 14-3-3 protein Rad24, but not Rad25 which remains bound to Ssp1. The loss of rad24 in ssp1− cells reduces the severity of hyperosmotic stress response and relieves mitotic delay. Conversely, overexpression of rad24 exacerbates stress response and concomitant cell elongation. rad24− does not impair stress-induced localization of Ssp1 to the cell membrane, however this response is almost completely absent in cells overexpressing rad24.
Collapse
Affiliation(s)
- Silja I Freitag
- Department of Biology, Queen's University, 116 Barrie Street, Kingston, Ontario, Canada K7L 3N6
| | | | | |
Collapse
|
64
|
Rnd3 coordinates early steps of cortical neurogenesis through actin-dependent and -independent mechanisms. Nat Commun 2013; 4:1635. [PMID: 23535656 PMCID: PMC3920367 DOI: 10.1038/ncomms2614] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Accepted: 02/19/2013] [Indexed: 02/06/2023] Open
Abstract
The generation of neurons by neural stem cells is a highly choreographed process that requires extensive and dynamic remodelling of the cytoskeleton at each step of the process. The atypical RhoGTPase Rnd3 is expressed by progenitors in the embryonic brain but its role in early steps of neurogenesis has not been addressed. Here we show that silencing Rnd3 in the embryonic cerebral cortex interferes with the interkinetic nuclear migration of radial glial stem cells, disrupts their apical attachment and modifies the orientation of their cleavage plane. These defects are rescued by co-expression of a constitutively active form of cofilin, demonstrating that Rnd3-mediated disassembly of actin filaments coordinates the cellular behaviour of radial glia. Rnd3 also limits the divisions of basal progenitors via a distinct mechanism involving the suppression of cyclin D1 translation. Interestingly, although Rnd3 expression is controlled transcriptionally by Ascl1, this proneural factor is itself required in radial glial progenitors only for proper orientation of cell divisions.
Collapse
|
65
|
Fortin Ensign SP, Mathews IT, Symons MH, Berens ME, Tran NL. Implications of Rho GTPase Signaling in Glioma Cell Invasion and Tumor Progression. Front Oncol 2013; 3:241. [PMID: 24109588 PMCID: PMC3790103 DOI: 10.3389/fonc.2013.00241] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Accepted: 09/02/2013] [Indexed: 01/21/2023] Open
Abstract
Glioblastoma (GB) is the most malignant of primary adult brain tumors, characterized by a highly locally invasive cell population, as well as abundant proliferative cells, neoangiogenesis, and necrosis. Clinical intervention with chemotherapy or radiation may either promote or establish an environment for manifestation of invasive behavior. Understanding the molecular drivers of invasion in the context of glioma progression may be insightful in directing new treatments for patients with GB. Here, we review current knowledge on Rho family GTPases, their aberrant regulation in GB, and their effect on GB cell invasion and tumor progression. Rho GTPases are modulators of cell migration through effects on actin cytoskeleton rearrangement; in non-neoplastic tissue, expression and activation of Rho GTPases are normally under tight regulation. In GB, Rho GTPases are deregulated, often via hyperactivity or overexpression of their activators, Rho GEFs. Downstream effectors of Rho GTPases have been shown to promote invasiveness and, importantly, glioma cell survival. The study of aberrant Rho GTPase signaling in GB is thus an important investigation of cell invasion as well as treatment resistance and disease progression.
Collapse
Affiliation(s)
- Shannon Patricia Fortin Ensign
- Cancer and Cell Biology Division, Translational Genomics Research Institute , Phoenix, AZ , USA ; Cancer Biology Graduate Interdisciplinary Program, University of Arizona , Tucson, AZ , USA
| | | | | | | | | |
Collapse
|
66
|
Lonjedo M, Poch E, Mocholí E, Hernández-Sánchez M, Ivorra C, Franke TF, Guasch RM, Pérez-Roger I. The Rho family member RhoE interacts with Skp2 and is degraded at the proteasome during cell cycle progression. J Biol Chem 2013; 288:30872-82. [PMID: 24045951 DOI: 10.1074/jbc.m113.511105] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
RhoE/Rnd3 is an atypical member of the Rho family of small GTPases. In addition to regulating actin cytoskeleton dynamics, RhoE is involved in the regulation of cell proliferation, survival, and metastasis. We examined RhoE expression levels during cell cycle and investigated mechanisms controlling them. We show that RhoE accumulates during G1, in contact-inhibited cells, and when the Akt pathway is inhibited. Conversely, RhoE levels rapidly decrease at the G1/S transition and remain low for most of the cell cycle. We also show that the half-life of RhoE is shorter than that of other Rho proteins and that its expression levels are regulated by proteasomal degradation. The expression patterns of RhoE overlap with that of the cell cycle inhibitor p27. Consistently with an involvement of RhoE in cell cycle regulation, RhoE and p27 levels decrease after overexpression of the F-box protein Skp2. We have identified a region between amino acids 231 and 240 of RhoE as the Skp2-interacting domain and Lys(235) as the substrate for ubiquitylation. Based on our results, we propose a mechanism according to which proteasomal degradation of RhoE by Skp2 regulates its protein levels to control cellular proliferation.
Collapse
Affiliation(s)
- Marta Lonjedo
- From the Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad CEU Cardenal Herrera, 46113-Moncada (Valencia), Spain
| | | | | | | | | | | | | | | |
Collapse
|
67
|
Variants in phospholipid metabolism and upstream regulators and non-small cell lung cancer susceptibility. Clin Transl Oncol 2013; 16:107-12. [DOI: 10.1007/s12094-013-1080-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 07/09/2013] [Indexed: 10/26/2022]
|
68
|
Riou P, Kjær S, Garg R, Purkiss A, George R, Cain R, Bineva G, Reymond N, McColl B, Thompson A, O’Reilly N, McDonald N, Parker P, Ridley A. 14-3-3 proteins interact with a hybrid prenyl-phosphorylation motif to inhibit G proteins. Cell 2013; 153:640-53. [PMID: 23622247 PMCID: PMC3690454 DOI: 10.1016/j.cell.2013.03.044] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Revised: 01/22/2013] [Accepted: 03/29/2013] [Indexed: 12/13/2022]
Abstract
Signaling through G proteins normally involves conformational switching between GTP- and GDP-bound states. Several Rho GTPases are also regulated by RhoGDI binding and sequestering in the cytosol. Rnd proteins are atypical constitutively GTP-bound Rho proteins, whose regulation remains elusive. Here, we report a high-affinity 14-3-3-binding site at the C terminus of Rnd3 consisting of both the Cys241-farnesyl moiety and a Rho-associated coiled coil containing protein kinase (ROCK)-dependent Ser240 phosphorylation site. 14-3-3 binding to Rnd3 also involves phosphorylation of Ser218 by ROCK and/or Ser210 by protein kinase C (PKC). The crystal structure of a phosphorylated, farnesylated Rnd3 peptide with 14-3-3 reveals a hydrophobic groove in 14-3-3 proteins accommodating the farnesyl moiety. Functionally, 14-3-3 inhibits Rnd3-induced cell rounding by translocating it from the plasma membrane to the cytosol. Rnd1, Rnd2, and geranylgeranylated Rap1A interact similarly with 14-3-3. In contrast to the canonical GTP/GDP switch that regulates most Ras superfamily members, our results reveal an unprecedented mechanism for G protein inhibition by 14-3-3 proteins.
Collapse
Affiliation(s)
- Philippe Riou
- Randall Division of Cell and Molecular Biophysics, New Hunt’s House, Guy’s Campus, King’s College London, London SE1 1UL, UK
- Protein Phosphorylation Laboratory, Cancer Research UK London Research Institute, Lincoln’s Inn Fields, London WC2A 3LY, UK
| | - Svend Kjær
- Protein Purification Facility, Cancer Research UK London Research Institute, Lincoln’s Inn Fields, London WC2A 3LY, UK
| | - Ritu Garg
- Randall Division of Cell and Molecular Biophysics, New Hunt’s House, Guy’s Campus, King’s College London, London SE1 1UL, UK
| | - Andrew Purkiss
- Structural Biology Laboratory, Cancer Research UK London Research Institute, Lincoln’s Inn Fields, London WC2A 3LY, UK
| | - Roger George
- Protein Purification Facility, Cancer Research UK London Research Institute, Lincoln’s Inn Fields, London WC2A 3LY, UK
| | - Robert J. Cain
- Randall Division of Cell and Molecular Biophysics, New Hunt’s House, Guy’s Campus, King’s College London, London SE1 1UL, UK
| | - Ganka Bineva
- Peptide Synthesis Laboratory, Cancer Research UK London Research Institute, Lincoln’s Inn Fields, London WC2A 3LY, UK
| | - Nicolas Reymond
- Randall Division of Cell and Molecular Biophysics, New Hunt’s House, Guy’s Campus, King’s College London, London SE1 1UL, UK
| | - Brad McColl
- Randall Division of Cell and Molecular Biophysics, New Hunt’s House, Guy’s Campus, King’s College London, London SE1 1UL, UK
| | - Andrew J. Thompson
- MRC Centre for Neurodegeneration Research, De Crespigny Park, King's College London, London SE5 8AF, UK
- The Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London SW3 6JB, UK
| | - Nicola O’Reilly
- Peptide Synthesis Laboratory, Cancer Research UK London Research Institute, Lincoln’s Inn Fields, London WC2A 3LY, UK
| | - Neil Q. McDonald
- Structural Biology Laboratory, Cancer Research UK London Research Institute, Lincoln’s Inn Fields, London WC2A 3LY, UK
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Malet Street, Birkbeck College, University of London, London WC1E 7HX, UK
| | - Peter J. Parker
- Division of Cancer Studies, New Hunt’s House, Guy’s Campus, King’s College London, London SE1 1UL, UK
- Protein Phosphorylation Laboratory, Cancer Research UK London Research Institute, Lincoln’s Inn Fields, London WC2A 3LY, UK
| | - Anne J. Ridley
- Randall Division of Cell and Molecular Biophysics, New Hunt’s House, Guy’s Campus, King’s College London, London SE1 1UL, UK
| |
Collapse
|
69
|
Interaction characteristics of Plexin-B1 with Rho family proteins. Biochem Biophys Res Commun 2013; 434:785-90. [PMID: 23603360 DOI: 10.1016/j.bbrc.2013.04.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2013] [Accepted: 04/10/2013] [Indexed: 11/22/2022]
Abstract
Plexin-B1 regulates various cellular processes interacting directly with several Rho proteins. Molecular details of these interactions are, however, not well understood. In this study, we examined in vitro and in silico the interaction of the Rho binding domain (B1RBD) of human Plexin-B1 with 11 different Rho proteins. We show that B1RBD binds in a GTP-dependent manner to Rac1, Rac2, Rac3, Rnd1, Rnd2, Rnd3, and RhoD, but not to RhoA, Cdc42, RhoG, or Rif. Interestingly, Rnd1 competitively displaces the Rac1 from B1RBD but not vice versa. Structure-function analysis revealed a negatively charged loop region, called B1L(31), which may facilitate a selective B1RBD interaction with Rho proteins.
Collapse
|
70
|
Gottesbühren U, Garg R, Riou P, McColl B, Brayson D, Ridley AJ. Rnd3 induces stress fibres in endothelial cells through RhoB. Biol Open 2013; 2:210-6. [PMID: 23430146 PMCID: PMC3575655 DOI: 10.1242/bio.20123574] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Accepted: 11/12/2012] [Indexed: 01/09/2023] Open
Abstract
Rnd proteins are atypical Rho family proteins that do not hydrolyse GTP and are instead regulated by expression levels and post-translational modifications. Rnd1 and Rnd3/RhoE induce loss of actin stress fibres and cell rounding in multiple cell types, whereas responses to Rnd2 are more variable. Here we report the responses of endothelial cells to Rnd proteins. Rnd3 induces a very transient decrease in stress fibres but subsequently stimulates a strong increase in stress fibres, in contrast to the reduction observed in other cell types. Rnd2 also increases stress fibres whereas Rnd1 induces a loss of stress fibres and weakening of cell-cell junctions. Rnd3 does not act through any of its known signalling partners and does not need to associate with membranes to increase stress fibres. Instead, it acts by increasing RhoB expression, which is then required for Rnd3-induced stress fibre assembly. Rnd2 also increases RhoB levels. These data indicate that the cytoskeletal response to Rnd3 expression is dependent on cell type and context, and identify regulation of RhoB as a new mechanism for Rnd proteins to affect the actin cytoskeleton.
Collapse
Affiliation(s)
| | | | | | | | | | - Anne J. Ridley
- Randall Division of Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, UK
| |
Collapse
|
71
|
Bhavsar PJ, Infante E, Khwaja A, Ridley AJ. Analysis of Rho GTPase expression in T-ALL identifies RhoU as a target for Notch involved in T-ALL cell migration. Oncogene 2013; 32:198-208. [PMID: 22349824 PMCID: PMC3378627 DOI: 10.1038/onc.2012.42] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2011] [Revised: 01/06/2012] [Accepted: 01/06/2012] [Indexed: 01/04/2023]
Abstract
NOTCH1 is frequently mutated in T-cell acute lymphoblastic leukaemia (T-ALL), and can stimulate T-ALL cell survival and proliferation. Here we explore the hypothesis that Notch1 also alters T-ALL cell migration. Rho GTPases are well known to regulate cell adhesion and migration. We have analysed the expression levels of Rho GTPases in primary T-ALL samples compared with normal T cells by quantitative PCR. We found that 5 of the 20 human Rho genes are highly and consistently upregulated in T-ALL, and 3 further Rho genes are expressed in T-ALL but not detectable in normal T cells. Of these, RHOU expression is highly correlated with the expression of the Notch1 target DELTEX-1. Inhibition of Notch1 signalling with a γ-secretase inhibitor (GSI) or Notch1 RNA interference reduced RhoU expression in T-ALL cells, whereas constitutively active Notch1 increased RhoU expression. In addition, Notch1 or RhoU depletion, or GSI treatment, inhibits T-ALL cell adhesion, migration and chemotaxis. These results indicate that NOTCH1 mutation stimulates T-ALL cell migration through RhoU upregulation that could contribute to the leukaemia cell dissemination.
Collapse
Affiliation(s)
- Parag J. Bhavsar
- Randall Division of Cell and Molecular Biophysics, King’s College London, New Hunt’s House, Guy’s Campus, London SE1 1UL, UK
| | - Elvira Infante
- Randall Division of Cell and Molecular Biophysics, King’s College London, New Hunt’s House, Guy’s Campus, London SE1 1UL, UK
- National Institute for Health Research (NIHR), Biomedical Research Centre, Guy’s and St Thomas’ NHS and King’s College London, London, UK
| | - Asim Khwaja
- UCL Cancer Institute, University College London, London, UK
| | - Anne J. Ridley
- Randall Division of Cell and Molecular Biophysics, King’s College London, New Hunt’s House, Guy’s Campus, London SE1 1UL, UK
| |
Collapse
|
72
|
Ma W, Wong CCL, Tung EKK, Wong CM, Ng IOL. RhoE is frequently down-regulated in hepatocellular carcinoma (HCC) and suppresses HCC invasion through antagonizing the Rho/Rho-kinase/myosin phosphatase target pathway. Hepatology 2013; 57:152-61. [PMID: 22829315 DOI: 10.1002/hep.25987] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Accepted: 07/16/2012] [Indexed: 12/11/2022]
Abstract
UNLABELLED Deregulation of Rho guanosine triphosphatase (GTPase) pathways plays an important role in tumorigenesis and metastasis of hepatocellular carcinoma (HCC). RhoE/Rnd3 belongs to an atypical subfamily of the RhoGTPase, the Rnd family, as it lacks the intrinsic GTPase activity and remains always in its active GTP-bound form. In this study we investigated the role of RhoE in HCC. We examined the expression of RhoE in primary HCC samples from patients predominantly infected with the hepatitis B virus (HBV) and found that the RhoE messenger RNA (mRNA) level was frequently down-regulated (83.1%, 59/71) in HCCs. Low expression of RhoE in the tumors was significantly associated with shorter disease-free survival (P = 0.020) of the patients. Knockdown of RhoE by short-hairpin RNA using a lentiviral approach led to increased cell motility and invasiveness in SMMC7721 and BEL7402 HCC cells. Moreover, in vivo an orthotopic liver injection model in nude mice further demonstrated that knockdown of RhoE enhanced local invasion of HCC cells in the livers, with more invasive tumor front and increased incidence of venous invasion. Mechanistically, stable knockdown of RhoE in HCC cells significantly enhanced the phosphorylation of myosin phosphatase, promoted assembly of stress fibers, and increased the formation of plasma membrane blebbings, all these changes and activities being associated with activation of the Rho/Rho-kinase (ROCK) pathway. CONCLUSION RhoE was frequently down-regulated in predominantly HBV-associated HCCs and this down-regulation was associated with a more aggressive HCC phenotype. RhoE regulated the cytoskeleton remodeling and suppressed HCC motility and invasiveness by way of inhibiting the Rho/ROCK axis.
Collapse
Affiliation(s)
- Wei Ma
- State Key Laboratory for Liver Research, University of Hong Kong, Hong Kong
| | | | | | | | | |
Collapse
|
73
|
Klingauf M, Beck M, Berge U, Turgay Y, Heinzer S, Horvath P, Kroschewski R. The tumour suppressor DiRas3 interacts with C-RAF and downregulates MEK activity to restrict cell migration. Biol Cell 2012; 105:91-107. [DOI: 10.1111/boc.201200030] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Accepted: 11/13/2012] [Indexed: 11/26/2022]
|
74
|
miR-199a-5p regulates urothelial permeability and may play a role in bladder pain syndrome. THE AMERICAN JOURNAL OF PATHOLOGY 2012. [PMID: 23201090 DOI: 10.1016/j.ajpath.2012.10.020] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Defects in urothelial integrity resulting in leakage and activation of underlying sensory nerves are potential causative factors of bladder pain syndrome, a clinical syndrome of pelvic pain and urinary urgency/frequency in the absence of a specific cause. Herein, we identified the microRNA miR-199a-5p as an important regulator of intercellular junctions. On overexpression in urothelial cells, it impairs correct tight junction formation and leads to increased permeability. miR-199a-5p directly targets mRNAs encoding LIN7C, ARHGAP12, PALS1, RND1, and PVRL1 and attenuates their expression levels to a similar extent. Using laser microdissection, we showed that miR-199a-5p is predominantly expressed in bladder smooth muscle but that it is also detected in mature bladder urothelium and primary urothelial cultures. In the urothelium, its expression can be up-regulated after activation of cAMP signaling pathways. While validating miR-199a-5p targets, we delineated novel functions of LIN7C and ARHGAP12 in urothelial integrity and confirmed the essential role of PALS1 in establishing and maintaining urothelial polarity and junction assembly. The present results point to a possible link between miR-199a-5p expression and the control of urothelial permeability in bladder pain syndrome. Up-regulation of miR-199a-5p and concomitant down-regulation of its multiple targets might be detrimental to the establishment of a tight urothelial barrier, leading to chronic pain.
Collapse
|
75
|
Goh LL, Manser E. The GTPase-deficient Rnd proteins are stabilized by their effectors. J Biol Chem 2012; 287:31311-20. [PMID: 22807448 DOI: 10.1074/jbc.m111.327056] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Rnd proteins are Rho family GTP-binding proteins with cellular functions that antagonize RhoA signaling. We recently described a new Rnd3 effector Syx, also named PLEKHG5, that interacts with Rnds via a Raf1-like "Ras-binding domain." Syx is a multidomain RhoGEF that participates in early zebrafish development. Here we demonstrated that Rnd1, Rnd2, and Rnd3 stability is acutely dependent on interaction with their effectors such as Syx or p190 RhoGAP. Although Rnd3 turnover is blocked by treatment of cells with MG132, we provide evidence that such turnover is mediated indirectly by effects on the Rnd3 effectors, rather than on Rnd3 itself, which is not significantly ubiquitinated. The minimal regions of Syx and p190 RhoGAP that bind Rnd3 are not sequence-related but have similar effects. We have identified features that allow for Rnd3 turnover including a conserved Lys-45 close to the switch I region and the C-terminal membrane-binding domain of Rnd3, which cannot be substituted by the equivalent Cdc42 CAAX sequence. By contrast, an effector binding-defective mutant of Rnd3 when overexpressed undergoes turnover at normal rates. Interestingly the activity of the RhoA-regulated kinase ROCK stimulates Rnd3 turnover. This study suggests that Rnd proteins are regulated through feedback mechanisms in cells where the level of effectors and RhoA activity influence the stability of Rnd proteins. This effector feedback behavior is analogous to the ability of ACK1 and PAK1 to prolong the lifetime of the active GTP-bound state of Cdc42 and Rac1.
Collapse
Affiliation(s)
- Liuh Ling Goh
- Rho GTPases Signaling Group, Institute of Medical Biology, 8A Biomedical Grove, 06-06 Immunos Building 138648, Singapore
| | | |
Collapse
|
76
|
Ostano P, Bione S, Belgiovine C, Chiodi I, Ghimenti C, Scovassi AI, Chiorino G, Mondello C. Cross-analysis of gene and miRNA genome-wide expression profiles in human fibroblasts at different stages of transformation. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2012; 16:24-36. [PMID: 22321013 DOI: 10.1089/omi.2011.0049] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
We have developed a cellular system constituted of human telomerase immortalized fibroblasts that gradually underwent neoplastic transformation during propagation in culture. We exploited this cellular system to investigate gene and miRNA transcriptional programs in cells at different stages of propagation, representing five different phases along the road to transformation, from non-transformed cells up to tumorigenic and metastatic ones. Here we show that gene and miRNA expression profiles were both able to divide cells according to their transformation phase. We identified more than 1,700 genes whose expression was highly modulated in cells at at least one propagation stage and we found that the number of modulated genes progressively increased at successive stages of transformation. These genes identified processes significantly deregulated in tumorigenic cells, such as cell differentiation, cell movement and extracellular matrix remodeling, cell cycle and apoptosis, together with upregulation of several cancer testis antigens. Alterations in cell cycle, apoptosis, and cancer testis antigen expression were particular hallmarks of metastatic cells. A parallel deregulation of a panel of 43 miRNAs strictly connected to the p53 and c-Myc pathways and with oncogenic/oncosuppressive functions was also found. Our results indicate that cen3tel cells can be a useful model for human fibroblast neoplastic transformation, which appears characterized by complex and peculiar alterations involving both genetic and epigenetic reprogramming, whose elucidation could provide useful insights into regulatory networks underlying cancerogenesis.
Collapse
Affiliation(s)
- Paola Ostano
- Fondazione Edo ed Elvo Tempia Valenta, Biella, Italy
| | | | | | | | | | | | | | | |
Collapse
|
77
|
Grise F, Sena S, Bidaud-Meynard A, Baud J, Hiriart JB, Makki K, Dugot-Senant N, Staedel C, Bioulac-Sage P, Zucman-Rossi J, Rosenbaum J, Moreau V. Rnd3/RhoE Is down-regulated in hepatocellular carcinoma and controls cellular invasion. Hepatology 2012; 55:1766-75. [PMID: 22234932 DOI: 10.1002/hep.25568] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
UNLABELLED We performed a review of public microarray data that revealed a significant down-regulation of Rnd3 expression in hepatocellular carcinoma (HCC), as compared to nontumor liver. Rnd3/RhoE is an atypical RhoGTPase family member because it is always under its active GTP-bound conformation and not sensitive to classical regulators. Rnd3 down-regulation was validated by quantitative real-time polymerase chain reaction in 120 independent tumors. Moreover, Rnd3 down-expression was confirmed using immunohistochemistry on tumor sections and western blotting on human tumor and cell-line extracts. Rnd3 expression was significantly lower in invasive tumors with satellite nodules. Overexpression and silencing of Rnd3 in Hep3B cells led to decreased and increased three-dimensional cell motility, respectively. The short interfering RNA-mediated down-regulation of Rnd3 expression induced a loss of E-cadherin at cell-cell junctions that was linked to epithelial-mesenchymal transition through the up-regulation of the zinc finger E-box binding homeobox protein, ZEB2, and the down-regulation of miR-200b and miR-200c. Rnd3 knockdown mediated tumor hepatocyte invasion in a matrix-metalloproteinase-independent, and Rac1-dependent manner. CONCLUSION Rnd3 down-regulation provides an invasive advantage to tumor hepatocytes, suggesting that RND3 might represent a metastasis suppressor gene in HCC.
Collapse
Affiliation(s)
- Florence Grise
- INSERM, Physiopathologie du Cancer du Foie, U1053, Bordeaux, France
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
78
|
Peris B, Gonzalez-Granero S, Ballester-Lurbe B, García-Verdugo JM, Pérez-Roger I, Guerri C, Terrado J, Guasch RM. Neuronal polarization is impaired in mice lacking RhoE expression. J Neurochem 2012; 121:903-14. [DOI: 10.1111/j.1471-4159.2012.07733.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
79
|
Zhao H, Yang J, Fan T, Li S, Ren X. RhoE functions as a tumor suppressor in esophageal squamous cell carcinoma and modulates the PTEN/PI3K/Akt signaling pathway. Tumour Biol 2012; 33:1363-74. [PMID: 22477709 DOI: 10.1007/s13277-012-0384-5] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Accepted: 03/14/2012] [Indexed: 12/27/2022] Open
Abstract
Emerging evidence indicates that RhoE as novel member of the Rho GTPases family plays an essential role in carcinogenesis and tumor progression of human various tumors, but the functional significance of RhoE in human esophageal squamous cell carcinoma (ESCC) is still unclear. In the current study, RhoE expression in ESCC tissues and cells was examined, and the biological functions of RhoE in ESCC cells were determined. The results revealed that RhoE expression at mRNA and protein levels was significantly downregulated in ESCC tissues and cell lines (P < 0.05). RhoE expression was tightly associated with differentiation degree, clinical staging, and lymph node metastasis of the patients with ESCC (P < 0.05), but no significant correlations were found between RhoE expression and gender or age of the patients with ESCC (P > 0.05). Additionally, we found that downregulation of RhoE expression in ESCC cells promoted cell proliferation, cell cycle progression, as well as cell invasion in vitro, and inhibited cell apoptosis. Conversely, upregulation of RhoE expression in ESCC cells inhibited cell proliferation, arrested cell cycle at G0/G1 phase, reduced cell invasion, and promoted cell apoptosis. Furthermore, the downregulation of RhoE expression significantly reduced PTEN level and enhanced pAkt level; however, elevation of RhoE expression markedly increased PTEN level and decreased pAkt level. Stepwise investigations demonstrated that overexpression of RhoE in ESCC cells increased the expressions of p27 and bax proteins but decreased the expressions of cyclin D1 and bcl-2 proteins. These data demonstrate that RhoE may play a driving role in the development and progression of ESCC, and targeting the RhoE may be an effective and feasible approach for treatment of ESCC.
Collapse
Affiliation(s)
- Hui Zhao
- Department of Cardiothoracic Surgery, Huaihe Hospital of Henan University, Kaifeng, Henan, 475000, People's Republic China
| | | | | | | | | |
Collapse
|
80
|
Furuta D, Yamane M, Tsujiuchi T, Moriyama R, Fukushima N. Lysophosphatidic acid induces neurite branch formation through LPA3. Mol Cell Neurosci 2012; 50:21-34. [PMID: 22465231 DOI: 10.1016/j.mcn.2012.03.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2011] [Revised: 02/03/2012] [Accepted: 03/14/2012] [Indexed: 01/13/2023] Open
Abstract
Although neurite branching is crucial for neuronal network formation after birth, its underlying mechanisms remain unclear. Here, we demonstrate that lysophosphatidic acid (LPA) stimulates neurite branching through a novel signaling pathway. Treatment of neuronal cell lines with LPA resulted in neurite branch formation when LPA(3) receptor was introduced. The effects of LPA were blocked by inhibition of G(q) signaling. Furthermore, expression of inhibitory mutants of the small GTPase Rnd2/Rho7 or an Rnd2 effector rapostlin abolished LPA(3)-mediated neurite branching. The LPA(3) agonist 2(S)-OMPT or LPA also induced axonal branch formation in hippocampal neurons, which was blocked by G(q) and Rnd2 pathway inhibition or LPA(3) knockdown. These findings suggest that the novel signaling pathway involving LPA(3), G(q), and Rnd2 may play an important role in neuronal network formation.
Collapse
Affiliation(s)
- Daisuke Furuta
- Division of Molecular Neurobiology, Department of Life Science, Kinki University, Higashiosaka, Japan
| | | | | | | | | |
Collapse
|
81
|
Up-regulated miR-17 promotes cell proliferation, tumour growth and cell cycle progression by targeting the RND3 tumour suppressor gene in colorectal carcinoma. Biochem J 2012; 442:311-21. [PMID: 22132820 DOI: 10.1042/bj20111517] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Emerging evidence indicates that the miR-17 family may have a causal role in human cancer tumorigenesis, but their specific effects on the occurrence of CRC (colorectal carcinoma) are still poorly understood. In the present study, we profiled CRC tissue samples by miRNA (microRNA) microarray and found that four members of the miR-17 family had higher expression in CRC tissues than in normal tissues. This finding was further validated by qRT-PCR (quantitative reverse transcription PCR). Transfecting CRC cells with an inhibitor of miR-17 lowered their ability to proliferate and induced G0/G1 arrest. We also confirmed that miR-17 exerted this function by directly targeting RND3 in vitro, and that the expression of miR-17 was negatively correlated with that of RND3 in CRC tissues and CRC cells. Moreover, miR-17 inhibition led to tumour growth suppression and up-regulation of RND3 expression in a nude mouse xenograft model. RND3 expression was found to be significantly lower in CRC tissues than in normal tissues and adenomas, indicating that RND3 may act as a tumour suppressor gene in CRC. In conclusion, the present study suggests that miR-17 plays an important role in CRC carcinogenesis by targeting RND3 and may be a therapeutic agent for CRC.
Collapse
|
82
|
RhoE is regulated by cyclic AMP and promotes fusion of human BeWo choriocarcinoma cells. PLoS One 2012; 7:e30453. [PMID: 22272352 PMCID: PMC3260294 DOI: 10.1371/journal.pone.0030453] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Accepted: 12/16/2011] [Indexed: 11/19/2022] Open
Abstract
Fusion of placental villous cytotrophoblasts with the overlying syncytiotrophoblast is essential for the maintenance of successful pregnancy, and disturbances in this process have been implicated in pathological conditions such as pre-eclampsia and intra-uterine growth retardation. In this study we examined the role of the Rho GTPase family member RhoE in trophoblast differentiation and fusion using the BeWo choriocarcinoma cell line, a model of villous cytotrophoblast fusion. Treatment of BeWo cells with the cell permeable cyclic AMP analogue dibutyryl cyclic AMP (dbcAMP) resulted in a strong upregulation of RhoE at 24h, coinciding with the onset of fusion. Using the protein kinase A (PKA)-specific cAMP analogue N6-phenyl-cAMP, and a specific inhibitor of PKA (14–22 amide, PKI), we found that upregulation of RhoE by cAMP was mediated through activation of PKA signalling. Silencing of RhoE expression by RNA interference resulted in a significant decrease in dbcAMP-induced fusion. However, expression of differentiation markers human chorionic gonadotrophin and placental alkaline phosphatase was unaffected by RhoE silencing. Finally, we found that RhoE upregulation by dbcAMP was significantly reduced under hypoxic conditions in which cell fusion is impaired. These results show that induction of RhoE by cAMP is mediated through PKA and promotes BeWo cell fusion but has no effect on functional differentiation, supporting evidence that these two processes may be controlled by separate or diverging pathways.
Collapse
|
83
|
Abstract
In 1985, the first members of the Rho GTPase family were identified. Over the next 10 years, rapid progress was made in understanding Rho GTPase signalling. Multiple Rho GTPases were discovered in a wide range of eukaryotes, and shown to regulate a diverse range of cellular processes, including cytoskeletal dynamics, NADPH oxidase activation, cell migration, cell polarity, membrane trafficking, and transcription. The Rho regulators, guanine nucleotide exchange factors (GEFs), GTPase-activating proteins (GAPs), and guanine nucleotide dissociation inhibitors (GDIs), were found through a combination of biochemistry, genetics, and detective work. Downstream targets for Rho GTPases were also rapidly identified, and linked to Rho-regulated cellular responses. In parallel, a wide range of bacterial proteins were found to modify Rho proteins or alter their activity in cells, many of which turned out to be useful tools to study Rho functions. More recent work has delineated where Rho GTPases act in cells, the molecular pathways linking some of them to specific cellular responses, and their functions in the development of multicellular organisms.
Collapse
Affiliation(s)
- Anne J Ridley
- Randall Division of Cell and Molecular Biophysics, King's College London, London, UK.
| |
Collapse
|
84
|
Luo H, Dong Z, Zou J, Zeng Q, Wu D, Liu L. Down-regulation of RhoE is associated with progression and poor prognosis in hepatocellular carcinoma. J Surg Oncol 2011; 105:699-704. [PMID: 22213123 DOI: 10.1002/jso.23019] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2011] [Accepted: 12/04/2011] [Indexed: 12/13/2022]
Abstract
BACKGROUND RhoE is an atypical member of Rho GTPases family, which is a crucial regulator of cytoskeletal dynamics, cell cycle progression, and cell proliferation. Previous studies have reported that RhoE was aberrantly expressed in several human cancers, but the role of RhoE in hepatocellular carcinoma (HCC) remained poor understood. OBJECTIVES This study investigated the expression of RhoE and its clinical significance on the outcome of patients with HCC. METHODS The expression of RhoE was examined in HCC patients and then the prognostic impact of the RhoE expression status was evaluated by univariate and multivariate analysis. RESULTS RhoE was down-regulated in HCC cell lines and tissues compared with normal hepatocyte line (HL-7702) and non-cancerous liver tissues. The expression of RhoE was significantly negatively associated with serum AFP (P = 0.013) and tumor grade (P = 0.016). Furthermore, the patients with low expression of RhoE had a shorter survival (P = 0.002) than those with high expression. Univariate and multivariate analysis showed that RhoE expression was a significant and independent prognostic predictor for HCC patients (P = 0.016). CONCLUSIONS RhoE, down-regulated in patients with HCC, could serve as an independent prognostic predictor for patients with HCC.
Collapse
Affiliation(s)
- Hesan Luo
- Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China
| | | | | | | | | | | |
Collapse
|
85
|
Mocholí E, Ballester-Lurbe B, Arqué G, Poch E, Peris B, Guerri C, Dierssen M, Guasch RM, Terrado J, Pérez-Roger I. RhoE deficiency produces postnatal lethality, profound motor deficits and neurodevelopmental delay in mice. PLoS One 2011; 6:e19236. [PMID: 21552537 PMCID: PMC3084285 DOI: 10.1371/journal.pone.0019236] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Accepted: 03/30/2011] [Indexed: 01/02/2023] Open
Abstract
Rnd proteins are a subfamily of Rho GTPases involved in the control of actin cytoskeleton dynamics and other cell functions such as motility, proliferation and survival. Unlike other members of the Rho family, Rnd proteins lack GTPase activity and therefore remain constitutively active. We have recently described that RhoE/Rnd3 is expressed in the Central Nervous System and that it has a role in promoting neurite formation. Despite their possible relevance during development, the role of Rnd proteins in vivo is not known. To get insight into the in vivo function of RhoE we have generated mice lacking RhoE expression by an exon trapping cassette. RhoE null mice (RhoE gt/gt) are smaller at birth, display growth retardation and early postnatal death since only half of RhoE gt/gt mice survive beyond postnatal day (PD) 15 and 100% are dead by PD 29. RhoE gt/gt mice show an abnormal body position with profound motor impairment and impaired performance in most neurobehavioral tests. Null mutant mice are hypoactive, show an immature locomotor pattern and display a significant delay in the appearance of the hindlimb mature responses. Moreover, they perform worse than the control littermates in the wire suspension, vertical climbing and clinging, righting reflex and negative geotaxis tests. Also, RhoE ablation results in a delay of neuromuscular maturation and in a reduction in the number of spinal motor neurons. Finally, RhoE gt/gt mice lack the common peroneal nerve and, consequently, show a complete atrophy of the target muscles. This is the first model to study the in vivo functions of a member of the Rnd subfamily of proteins, revealing the important role of Rnd3/RhoE in the normal development and suggesting the possible involvement of this protein in neurological disorders.
Collapse
Affiliation(s)
- Enric Mocholí
- Department of Chemistry, Biochemistry and Molecular Biology, School of Health Sciences, Universidad CEU Cardenal Herrera, Moncada, Valencia, Spain
| | - Begoña Ballester-Lurbe
- Department of Animal Medicine and Surgery, School of Veterinary Sciences, Universidad CEU Cardenal Herrera, Moncada, Valencia, Spain
| | - Gloria Arqué
- Genes and Disease Program, Center for Genomic Regulation (CRG), Barcelona Biomedical Research Park (PRBB) and CIBER de Enfermedades Raras (CIBERER), Barcelona, Spain
| | - Enric Poch
- Department of Chemistry, Biochemistry and Molecular Biology, School of Health Sciences, Universidad CEU Cardenal Herrera, Moncada, Valencia, Spain
| | - Blanca Peris
- Laboratory of Cellular Pathology, Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - Consuelo Guerri
- Laboratory of Cellular Pathology, Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - Mara Dierssen
- Genes and Disease Program, Center for Genomic Regulation (CRG), Barcelona Biomedical Research Park (PRBB) and CIBER de Enfermedades Raras (CIBERER), Barcelona, Spain
| | - Rosa M. Guasch
- Laboratory of Cellular Pathology, Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - José Terrado
- Department of Animal Medicine and Surgery, School of Veterinary Sciences, Universidad CEU Cardenal Herrera, Moncada, Valencia, Spain
- * E-mail: (IP-R); (JT)
| | - Ignacio Pérez-Roger
- Department of Chemistry, Biochemistry and Molecular Biology, School of Health Sciences, Universidad CEU Cardenal Herrera, Moncada, Valencia, Spain
- * E-mail: (IP-R); (JT)
| |
Collapse
|
86
|
Auer M, Hausott B, Klimaschewski L. Rho GTPases as regulators of morphological neuroplasticity. Ann Anat 2011; 193:259-66. [PMID: 21459565 PMCID: PMC3143277 DOI: 10.1016/j.aanat.2011.02.015] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2011] [Accepted: 02/28/2011] [Indexed: 11/17/2022]
Abstract
GTPases function as intracellular, bimolecular switches by adopting different conformational states in response to binding GDP or GTP. Their activation is mediated through cell-surface receptors. Rho GTPases act on several downstream effectors involved in cellular morphogenesis, cell polarity, migration and cell division. In neurons, Rho GTPases regulate various features of dendritic and axonal outgrowth during development and regeneration mainly through their effects on the cytoskeleton. This review summarizes the main functions of Rho, Rac and Cdc42 GTPases as key regulators of morphological neuroplasticity under normal and pathological conditions.
Collapse
Affiliation(s)
- Maria Auer
- Division of Neuroanatomy, Medical University of Innsbruck, Muellerstrasse 59, Innsbruck, Austria
| | | | | |
Collapse
|