1
|
Bahar ME, Kim HJ, Kim DR. Targeting the RAS/RAF/MAPK pathway for cancer therapy: from mechanism to clinical studies. Signal Transduct Target Ther 2023; 8:455. [PMID: 38105263 PMCID: PMC10725898 DOI: 10.1038/s41392-023-01705-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 11/03/2023] [Accepted: 11/12/2023] [Indexed: 12/19/2023] Open
Abstract
Metastatic dissemination of solid tumors, a leading cause of cancer-related mortality, underscores the urgent need for enhanced insights into the molecular and cellular mechanisms underlying metastasis, chemoresistance, and the mechanistic backgrounds of individuals whose cancers are prone to migration. The most prevalent signaling cascade governed by multi-kinase inhibitors is the mitogen-activated protein kinase (MAPK) pathway, encompassing the RAS-RAF-MAPK kinase (MEK)-extracellular signal-related kinase (ERK) pathway. RAF kinase is a primary mediator of the MAPK pathway, responsible for the sequential activation of downstream targets, such as MEK and the transcription factor ERK, which control numerous cellular and physiological processes, including organism development, cell cycle control, cell proliferation and differentiation, cell survival, and death. Defects in this signaling cascade are associated with diseases such as cancer. RAF inhibitors (RAFi) combined with MEK blockers represent an FDA-approved therapeutic strategy for numerous RAF-mutant cancers, including melanoma, non-small cell lung carcinoma, and thyroid cancer. However, the development of therapy resistance by cancer cells remains an important barrier. Autophagy, an intracellular lysosome-dependent catabolic recycling process, plays a critical role in the development of RAFi resistance in cancer. Thus, targeting RAF and autophagy could be novel treatment strategies for RAF-mutant cancers. In this review, we delve deeper into the mechanistic insights surrounding RAF kinase signaling in tumorigenesis and RAFi-resistance. Furthermore, we explore and discuss the ongoing development of next-generation RAF inhibitors with enhanced therapeutic profiles. Additionally, this review sheds light on the functional interplay between RAF-targeted therapies and autophagy in cancer.
Collapse
Affiliation(s)
- Md Entaz Bahar
- Department of Biochemistry and Convergence Medical Sciences and Institute of Medical Science, Gyeongsang National University, College of Medicine, Jinju, South Korea
| | - Hyun Joon Kim
- Department of Anatomy and Convergence Medical Sciences and Institute of Medical Science, Gyeongsang National University, College of Medicine, Jinju, South Korea
| | - Deok Ryong Kim
- Department of Biochemistry and Convergence Medical Sciences and Institute of Medical Science, Gyeongsang National University, College of Medicine, Jinju, South Korea.
| |
Collapse
|
2
|
Hashemi Karoii D, Azizi H. A review of protein-protein interaction and signaling pathway of Vimentin in cell regulation, morphology and cell differentiation in normal cells. J Recept Signal Transduct Res 2022; 42:512-520. [PMID: 35296221 DOI: 10.1080/10799893.2022.2047199] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The Vimentin intermediate filament (VIF) is an essential cytoskeleton component. It shows dynamically changing expression patterns throughout various phases of the differentiation process, suggesting that the protein is physiologically important. Vimentin's essential functions have recently been clear, so Vimentin-deficient of animals was described as a change of morphology and signaling pathway. Recent research has discovered many vital roles for Vimentin that were previously unknown. VIF emerges as an organizer of many essential proteins involved in movement and cell signaling. The highly dynamic and complicated phosphorylation of VIF seems to be a regulator mechanism for various activities. Changes in IF expression patterns are often linked with cancer progression, especially those leading to enhanced invasion and cellular migration. This review will discuss the function of Vimentin intermediate filaments in normal cell physiology, cell adhesion structures, cell shape, and signaling pathways. The genes interaction and gene network linked with Vimentin will be discussed in more studies. However, research aimed at understanding the function of Vimentin in different signaling cascades and gene interactions might offer novel methods for creating therapeutic medicines. Enrichr GEO datasets used gene ontology (GO) and pathway enrichment analyses. STRING online was used to predict the functional connections of proteins-proteins, followed by Cytoscape analysis to find the master genes. Cytoscape and STRING research revealed that eight genes, Fas, Casp8, Casp6, Fadd, Ripk1, Des, Tnnc2, and Tnnt3, were required for protein-protein interactions with Vimentin genes involved in cell differentiation.
Collapse
Affiliation(s)
- Danial Hashemi Karoii
- Faculty of Biotechnology, Amol University of Special Modern Technologies, Amol, Iran
| | - Hossein Azizi
- Faculty of Biotechnology, Amol University of Special Modern Technologies, Amol, Iran
| |
Collapse
|
3
|
Agnetti G, Herrmann H, Cohen S. New roles for desmin in the maintenance of muscle homeostasis. FEBS J 2021; 289:2755-2770. [PMID: 33825342 DOI: 10.1111/febs.15864] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Revised: 02/06/2021] [Accepted: 04/04/2021] [Indexed: 12/11/2022]
Abstract
Desmin is the primary intermediate filament (IF) of cardiac, skeletal, and smooth muscle. By linking the contractile myofibrils to the sarcolemma and cellular organelles, desmin IF contributes to muscle structural and cellular integrity, force transmission, and mitochondrial homeostasis. Mutations in desmin cause myofibril misalignment, mitochondrial dysfunction, and impaired mechanical integrity leading to cardiac and skeletal myopathies in humans, often characterized by the accumulation of protein aggregates. Recent evidence indicates that desmin filaments also regulate proteostasis and cell size. In skeletal muscle, changes in desmin filament dynamics can facilitate catabolic events as an adaptive response to a changing environment. In addition, post-translational modifications of desmin and its misfolding in the heart have emerged as key determinants of homeostasis and disease. In this review, we provide an overview of the structural and cellular roles of desmin and propose new models for its novel functions in preserving the homeostasis of striated muscles.
Collapse
Affiliation(s)
- Giulio Agnetti
- Johns Hopkins University School of Medicine, Baltimore, MD, USA.,DIBINEM, University of Bologna, Italy
| | - Harald Herrmann
- Institute of Neuropathology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nürnberg, Germany
| | - Shenhav Cohen
- Faculty of Biology, Technion Institute of Technology, Haifa, Israel
| |
Collapse
|
4
|
Behl T, Sharma A, Sharma L, Sehgal A, Zengin G, Brata R, Fratila O, Bungau S. Exploring the Multifaceted Therapeutic Potential of Withaferin A and Its Derivatives. Biomedicines 2020; 8:E571. [PMID: 33291236 PMCID: PMC7762146 DOI: 10.3390/biomedicines8120571] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 12/01/2020] [Accepted: 12/04/2020] [Indexed: 12/12/2022] Open
Abstract
Withaferin A (WA), a manifold studied, C28-steroidal lactone withanolide found in Withania somnifera. Given its unique beneficial effects, it has gathered attention in the era of modern science. Cancer, being considered a "hopeless case and the leading cause of death worldwide, and the available conventional therapies have many lacunae in the form of side effects. The poly pharmaceutical natural compound, WA treatment, displayed attenuation of various cancer hallmarks by altering oxidative stress, promoting apoptosis, and autophagy, inhibiting cell proliferation, reducing angiogenesis, and metastasis progression. The cellular proteins associated with antitumor pathways were also discussed. WA structural modifications attack multiple signal transduction pathways and enhance the therapeutic outcomes in various diseases. Moreover, it has shown validated pharmacological effects against multiple neurodegenerative diseases by inhibiting acetylcholesterinases and butyrylcholinesterases enzyme activity, antidiabetic activity by upregulating adiponectin and preventing the phosphorylation of peroxisome proliferator-activated receptors (PPARγ), cardioprotective activity by AMP-activated protein kinase (AMPK) activation and suppressing mitochondrial apoptosis. The current review is an extensive survey of various WA associated disease targets, its pharmacokinetics, synergistic combination, modifications, and biological activities.
Collapse
Affiliation(s)
- Tapan Behl
- Chitkara College of Pharmacy, Chitkara University, Punjab 140401, India;
| | - Aditi Sharma
- School of Pharmaceutical Sciences, Shoolini University, Solan, Himachal Pradesh 173229, India; (A.S.); (L.S.)
| | - Lalit Sharma
- School of Pharmaceutical Sciences, Shoolini University, Solan, Himachal Pradesh 173229, India; (A.S.); (L.S.)
| | - Aayush Sehgal
- Chitkara College of Pharmacy, Chitkara University, Punjab 140401, India;
| | - Gokhan Zengin
- Department of Biology, Faculty of Science, Selcuk University Campus, Konya 42250, Turkey;
| | - Roxana Brata
- Department of Medical Disciplines, Faculty of Medicine and Pharmacy, University of Oradea, 410073 Oradea, Romania; (R.B.); (O.F.)
| | - Ovidiu Fratila
- Department of Medical Disciplines, Faculty of Medicine and Pharmacy, University of Oradea, 410073 Oradea, Romania; (R.B.); (O.F.)
| | - Simona Bungau
- Department of Pharmacy, Faculty of Medicine and Pharmacy, University of Oradea, 410028 Oradea, Romania
| |
Collapse
|
5
|
Javed E, Thangavel C, Frara N, Singh J, Mohanty I, Hypolite J, Birbe R, Braverman AS, Den RB, Rattan S, Zderic SA, Deshpande DA, Penn RB, Ruggieri MR, Chacko S, Boopathi E. Increased expression of desmin and vimentin reduces bladder smooth muscle contractility via JNK2. FASEB J 2019; 34:2126-2146. [PMID: 31909533 DOI: 10.1096/fj.201901301r] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 10/18/2019] [Accepted: 11/14/2019] [Indexed: 01/12/2023]
Abstract
Bladder dysfunction is associated with the overexpression of the intermediate filament (IF) proteins desmin and vimentin in obstructed bladder smooth muscle (BSM). However, the mechanisms by which these proteins contribute to BSM dysfunction are not known. Previous studies have shown that desmin and vimentin directly participate in signal transduction. In this study, we hypothesized that BSM dysfunction associated with overexpression of desmin or vimentin is mediated via c-Jun N-terminal kinase (JNK). We employed a model of murine BSM tissue in which increased expression of desmin or vimentin was induced by adenoviral transduction to examine the sufficiency of increased IF protein expression to reduce BSM contraction. Murine BSM strips overexpressing desmin or vimentin generated less force in response to KCl and carbachol relative to the levels in control murine BSM strips, an effect associated with increased JNK2 phosphorylation and reduced myosin light chain (MLC20 ) phosphorylation. Furthermore, desmin and vimentin overexpressions did not alter BSM contractility and MLC20 phosphorylation in strips isolated from JNK2 knockout mice. Pharmacological JNK2 inhibition produced results qualitatively similar to those caused by JNK2 knockout. These findings suggest that inhibition of JNK2 may improve diminished BSM contractility associated with obstructive bladder disease.
Collapse
Affiliation(s)
- Elham Javed
- Department of Medicine, Center for Translational Medicine, Thomas Jefferson University, Philadelphia, PA, USA
| | | | - Nagat Frara
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Jagmohan Singh
- Department of Medicine, Division of Gastroenterology & Hepatology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Ipsita Mohanty
- Department of Medicine, Division of Gastroenterology & Hepatology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Joseph Hypolite
- Department of Medicine, Center for Translational Medicine, Thomas Jefferson University, Philadelphia, PA, USA
| | - Ruth Birbe
- Department of Pathology and Laboratory Medicine, Cooper University Health Care, Camden, NJ, USA
| | - Alan S Braverman
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Robert B Den
- Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Satish Rattan
- Department of Medicine, Division of Gastroenterology & Hepatology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Stephen A Zderic
- Department of Urology, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Deepak A Deshpande
- Department of Medicine, Center for Translational Medicine, Thomas Jefferson University, Philadelphia, PA, USA
| | - Raymond B Penn
- Department of Medicine, Center for Translational Medicine, Thomas Jefferson University, Philadelphia, PA, USA
| | - Michael R Ruggieri
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Samuel Chacko
- Division of Urology, University of Pennsylvania, Philadelphia, PA, USA.,Department of Pathobiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Ettickan Boopathi
- Department of Medicine, Center for Translational Medicine, Thomas Jefferson University, Philadelphia, PA, USA.,Division of Urology, University of Pennsylvania, Philadelphia, PA, USA
| |
Collapse
|
6
|
Vohnoutka RB, Gulvady AC, Goreczny G, Alpha K, Handelman SK, Sexton JZ, Turner CE. The focal adhesion scaffold protein Hic-5 regulates vimentin organization in fibroblasts. Mol Biol Cell 2019; 30:3037-3056. [PMID: 31644368 PMCID: PMC6880880 DOI: 10.1091/mbc.e19-08-0442] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Focal adhesion (FA)-stimulated reorganization of the F-actin cytoskeleton regulates cellular size, shape, and mechanical properties. However, FA cross-talk with the intermediate filament cytoskeleton is poorly understood. Genetic ablation of the FA-associated scaffold protein Hic-5 in mouse cancer-associated fibroblasts (CAFs) promoted a dramatic collapse of the vimentin network, which was rescued following EGFP-Hic-5 expression. Vimentin collapse correlated with a loss of detergent-soluble vimentin filament precursors and decreased vimentin S72/S82 phosphorylation. Additionally, fluorescence recovery after photobleaching analysis indicated impaired vimentin dynamics. Microtubule (MT)-associated EB1 tracking and Western blotting of MT posttranslational modifications indicated no change in MT dynamics that could explain the vimentin collapse. However, pharmacological inhibition of the RhoGTPase Cdc42 in Hic-5 knockout CAFs rescued the vimentin collapse, while pan-formin inhibition with SMIFH2 promoted vimentin collapse in Hic-5 heterozygous CAFs. Our results reveal novel regulation of vimentin organization/dynamics by the FA scaffold protein Hic-5 via modulation of RhoGTPases and downstream formin activity.
Collapse
Affiliation(s)
- Rishel B Vohnoutka
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, NY 13210
| | - Anushree C Gulvady
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, NY 13210
| | - Gregory Goreczny
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, NY 13210
| | - Kyle Alpha
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, NY 13210
| | - Samuel K Handelman
- Division of Gastroenterology, Department of Internal Medicine, Michigan Medicine at the University of Michigan, Ann Arbor, MI 48109
| | - Jonathan Z Sexton
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, MI 48109
| | - Christopher E Turner
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, NY 13210
| |
Collapse
|
7
|
D'Amore C, Salizzato V, Borgo C, Cesaro L, Pinna LA, Salvi M. A Journey through the Cytoskeleton with Protein Kinase CK2. Curr Protein Pept Sci 2019; 20:547-562. [PMID: 30659536 DOI: 10.2174/1389203720666190119124846] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 12/21/2018] [Accepted: 01/09/2019] [Indexed: 01/15/2023]
Abstract
Substrate pleiotropicity, a very acidic phosphorylation consensus sequence, and an apparent uncontrolled activity, are the main features of CK2, a Ser/Thr protein kinase that is required for a plethora of cell functions. Not surprisingly, CK2 appears to affect cytoskeletal structures and correlated functions such as cell shape, mechanical integrity, cell movement and division. This review outlines our current knowledge of how CK2 regulates cytoskeletal structures, and discusses involved pathways and molecular mechanisms.
Collapse
Affiliation(s)
- Claudio D'Amore
- Department of Biomedical Sciences, University of Padova, Via U. Bassi 58/B, Padova, Italy
| | - Valentina Salizzato
- Department of Biomedical Sciences, University of Padova, Via U. Bassi 58/B, Padova, Italy.,CNR Institute of Neurosciences, Via U. Bassi 58/B, Padova, Italy
| | - Christian Borgo
- Department of Biomedical Sciences, University of Padova, Via U. Bassi 58/B, Padova, Italy
| | - Luca Cesaro
- Department of Biomedical Sciences, University of Padova, Via U. Bassi 58/B, Padova, Italy
| | - Lorenzo A Pinna
- Department of Biomedical Sciences, University of Padova, Via U. Bassi 58/B, Padova, Italy.,CNR Institute of Neurosciences, Via U. Bassi 58/B, Padova, Italy
| | - Mauro Salvi
- Department of Biomedical Sciences, University of Padova, Via U. Bassi 58/B, Padova, Italy
| |
Collapse
|
8
|
The Cytoskeleton-A Complex Interacting Meshwork. Cells 2019; 8:cells8040362. [PMID: 31003495 PMCID: PMC6523135 DOI: 10.3390/cells8040362] [Citation(s) in RCA: 181] [Impact Index Per Article: 36.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 04/15/2019] [Accepted: 04/15/2019] [Indexed: 12/22/2022] Open
Abstract
The cytoskeleton of animal cells is one of the most complicated and functionally versatile structures, involved in processes such as endocytosis, cell division, intra-cellular transport, motility, force transmission, reaction to external forces, adhesion and preservation, and adaptation of cell shape. These functions are mediated by three classical cytoskeletal filament types, as follows: Actin, microtubules, and intermediate filaments. The named filaments form a network that is highly structured and dynamic, responding to external and internal cues with a quick reorganization that is orchestrated on the time scale of minutes and has to be tightly regulated. Especially in brain tumors, the cytoskeleton plays an important role in spreading and migration of tumor cells. As the cytoskeletal organization and regulation is complex and many-faceted, this review aims to summarize the findings about cytoskeletal filament types, including substructures formed by them, such as lamellipodia, stress fibers, and interactions between intermediate filaments, microtubules and actin. Additionally, crucial regulatory aspects of the cytoskeletal filaments and the formed substructures are discussed and integrated into the concepts of cell motility. Even though little is known about the impact of cytoskeletal alterations on the progress of glioma, a final point discussed will be the impact of established cytoskeletal alterations in the cellular behavior and invasion of glioma.
Collapse
|
9
|
Nakhaei-Rad S, Haghighi F, Nouri P, Rezaei Adariani S, Lissy J, Kazemein Jasemi NS, Dvorsky R, Ahmadian MR. Structural fingerprints, interactions, and signaling networks of RAS family proteins beyond RAS isoforms. Crit Rev Biochem Mol Biol 2018; 53:130-156. [PMID: 29457927 DOI: 10.1080/10409238.2018.1431605] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Saeideh Nakhaei-Rad
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Fereshteh Haghighi
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Parivash Nouri
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Soheila Rezaei Adariani
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Jana Lissy
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Neda S Kazemein Jasemi
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Radovan Dvorsky
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Mohammad Reza Ahmadian
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| |
Collapse
|
10
|
Sanghvi-Shah R, Weber GF. Intermediate Filaments at the Junction of Mechanotransduction, Migration, and Development. Front Cell Dev Biol 2017; 5:81. [PMID: 28959689 PMCID: PMC5603733 DOI: 10.3389/fcell.2017.00081] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 08/30/2017] [Indexed: 01/04/2023] Open
Abstract
Mechanically induced signal transduction has an essential role in development. Cells actively transduce and respond to mechanical signals and their internal architecture must manage the associated forces while also being dynamically responsive. With unique assembly-disassembly dynamics and physical properties, cytoplasmic intermediate filaments play an important role in regulating cell shape and mechanical integrity. While this function has been recognized and appreciated for more than 30 years, continually emerging data also demonstrate important roles of intermediate filaments in cell signal transduction. In this review, with a particular focus on keratins and vimentin, the relationship between the physical state of intermediate filaments and their role in mechanotransduction signaling is illustrated through a survey of current literature. Association with adhesion receptors such as cadherins and integrins provides a critical interface through which intermediate filaments are exposed to forces from a cell's environment. As a consequence, these cytoskeletal networks are posttranslationally modified, remodeled and reorganized with direct impacts on local signal transduction events and cell migratory behaviors important to development. We propose that intermediate filaments provide an opportune platform for cells to both cope with mechanical forces and modulate signal transduction.
Collapse
Affiliation(s)
- Rucha Sanghvi-Shah
- Department of Biological Sciences, Rutgers University-NewarkNewark, NJ, United States
| | - Gregory F Weber
- Department of Biological Sciences, Rutgers University-NewarkNewark, NJ, United States
| |
Collapse
|
11
|
Yang L, Tang L, Dai F, Meng G, Yin R, Xu X, Yao W. Raf-1/CK2 and RhoA/ROCK signaling promote TNF-α-mediated endothelial apoptosis via regulating vimentin cytoskeleton. Toxicology 2017; 389:74-84. [PMID: 28743511 DOI: 10.1016/j.tox.2017.07.010] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 07/16/2017] [Accepted: 07/18/2017] [Indexed: 01/04/2023]
Abstract
Both RhoA/ROCK and Raf-1/CK2 pathway play essential roles in cell proliferation, apoptosis, differentiation, and multiple other common cellular functions. We previously reported that vimentin is responsible for TNF-α-induced cell apoptosis. Herein, we investigated the regulation of RhoA/ROCK and Raf-1/CK2 signaling on vimentin filaments and endothelial apoptosis mediated by TNF-α. Treatment with TNF-α significantly induced the activation of RhoA and ROCK, and the expression of ROCK1. RhoA deficiency could obviously inhibit ROCK activation and ROCK1 expression induced by TNF-α. Both RhoA deficiency and ROCK activity inhibition (Y-27632) greatly inhibited endothelial apoptosis and preserved cell viability in TNF-α-induced human umbilical vein endothelial cells (HUVECs). Also vimentin phosphorylation and the remodeling of vimentin or phospho-vimentin induced by TNF-α were obviously attenuated by RhoA suppression and ROCK inhibition. TNF-α-mediated vimentin cleavage was significantly inhibited by RhoA suppression and ROCK inhibition through decreasing the activation of caspase3 and 8. Furthermore, TNF-α treatment greatly enhanced the activation of Raf-1. Suppression of Raf-1 or CK2 by its inhibitor (GW5074 or TBB) blocked vimentin phosphorylation, remodeling and endothelial apoptosis, and preserved cell viability in TNF-α-induced HUVECs. However, Raf-1 inhibition showed no significant effect on TNF-α-induced ROCK expression and activation, suggesting that the regulation of Raf-1/CK2 signaling on vimentin was independent of ROCK. Taken together, these results indicate that both RhoA/ROCK and Raf-1/CK2 pathway are responsible for TNF-α-mediated endothelial cytotoxicity via regulating vimentin cytoskeleton.
Collapse
Affiliation(s)
- Lifeng Yang
- School of pharmacy, Nantong University, 19 QiXiu Road, Nantong 226001, China
| | - Lian Tang
- School of pharmacy, Nantong University, 19 QiXiu Road, Nantong 226001, China
| | - Fan Dai
- School of pharmacy, Nantong University, 19 QiXiu Road, Nantong 226001, China
| | - Guoliang Meng
- School of pharmacy, Nantong University, 19 QiXiu Road, Nantong 226001, China
| | - Runting Yin
- School of pharmacy, Nantong University, 19 QiXiu Road, Nantong 226001, China
| | - Xiaole Xu
- School of pharmacy, Nantong University, 19 QiXiu Road, Nantong 226001, China
| | - Wenjuan Yao
- School of pharmacy, Nantong University, 19 QiXiu Road, Nantong 226001, China.
| |
Collapse
|
12
|
Identification of Novel MAGE-G1-Interacting Partners in Retinoic Acid-Induced P19 Neuronal Differentiation Using SILAC-Based Proteomics. Sci Rep 2017; 7:44699. [PMID: 28374796 PMCID: PMC5379670 DOI: 10.1038/srep44699] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 02/13/2017] [Indexed: 12/22/2022] Open
Abstract
MAGE-G1 is a protein plays role in the early process of neurogenesis. However, the fundamental roles MAGE-G1 played in neurogenesis have not yet been completely understood. Finding the partners MAGE-G1 interacting with will surely contribute to the function study of MAGE-G1. In this study, using Stable Isotope Labeling by Amino acids in Cell culture-immunoprecipitation quantitative proteomics, we screened the interacting proteins of MAGE-G1 during retinoic acid -induced neuronal differentiation of P19 cells and firstly found that FSCN1 and VIME were potential novel MAGE-G1-interacting proteins. Then, the interaction between overexpressed MAGE-G1 and FSCN1 or VIME was validated by GST-pull down assay in bacteria and by co-immunoprecipitation assay in COS7 cells. Endogenous co-immunoprecipitation assay further confirmed that MAGE-G1 interacted with FSCN1 or VIME in P19 cells after a 6-day retinoic acid-induced neuronal differentiation. Those results provide a functional linkage between MAGE-G1 and FSCN1 or VIME and may facilitate a better understanding of the fundamental aspects of MAGE-G1 during neurogenesis.
Collapse
|
13
|
Cong H, Yao RY, Sun ZQ, Qiu WS, Yao YS, Feng TT, Xin C, Liang J, Yue LU. DNA hypermethylation of the vimentin gene inversely correlates with vimentin expression in intestinal- and diffuse-type gastric cancer. Oncol Lett 2015; 11:842-848. [PMID: 26870294 DOI: 10.3892/ol.2015.3937] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 07/16/2015] [Indexed: 01/26/2023] Open
Abstract
The vimentin gene is a hallmark of epithelial-to-mesenchymal transition and has been observed to be overexpressed in various types of tumor cell line and tissue. Previous studies have reported correlations between vimentin DNA methylation levels and subsequent vimentin expression levels in solid tumors, including breast and colorectal cancer; however, to the best of our knowledge, such a correlation has not been reported for gastric cancer (GC) using Lauren classification. Therefore, the present study aimed to quantify DNA methylation levels of the vimentin gene using quantitative (q) methylation-specific polymerase chain reaction (PCR) in intestinal-type GC cell lines (MKN-28, AGS and MKN-1), diffuse-type GC cell lines (SGC-7901, SNU-5 and KATO III), the GES-1 immortalized human non-neoplastic gastric epithelial cell line, as well as in tumor and paratumor normal tissue samples. Furthermore, the present study analyzed the messenger RNA expression of the vimentin gene in these cell lines and tissues by reverse transcription-qPCR. A comparison of the clinicopathological features was conducted between patients, grouped according to the Lauren classification. The present study identified that the vimentin promoter region was hypermethylated in all GC cell lines and tumor tissue samples when compared with immortalized normal gastric epithelial cells and paratumor normal tissues. In addition, vimentin promoter methylation levels were observed to be higher in intestinal-type cell lines when compared with those of diffuse-type lines and tissues. Correspondingly, vimentin expression levels were lower in intestinal-type gastric cell lines compared with those of diffuse-type cell lines and tissues, and were lowest in the non-neoplastic gastric cell line and paratumor normal tissues. Patients with diffuse-type GC were on average younger (P=0.023), and exhibited higher tumor (P=0.020), node (P=0.032) and TNM classification of malignant tumor stage (P=0.039) than those with intestinal-type GC. Following treatment of AGS cells (which demonstrated the highest methylation level of the vimentin gene) with 5-aza-2'-deoxycytidine, vimentin expression was restored significantly. Thus, the present study revealed that vimentin promoter methylation levels are inversely correlated with vimentin expression levels in GC (according to Lauren classification). High levels of methylation in the vimentin gene promoter region may be involved in carcinogenesis and the development of GC, and may provide a novel molecular classification for GC.
Collapse
Affiliation(s)
- Hui Cong
- Department of Oncology, Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, P.R. China; Tumor Molecular and Translational Medicine Lab, Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, P.R. China
| | - Ru-Yong Yao
- Central Laboratory, Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, P.R. China
| | - Zhen-Qing Sun
- Department of General Surgery, Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, P.R. China
| | - Wen-Sheng Qiu
- Department of Oncology, Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, P.R. China; Tumor Molecular and Translational Medicine Lab, Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, P.R. China
| | - Ya-Sai Yao
- Department of Oncology, Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, P.R. China
| | - Tong-Tong Feng
- Department of Oncology, Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, P.R. China
| | - Chao Xin
- Department of Oncology, Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, P.R. China
| | - Jun Liang
- Department of Oncology, Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, P.R. China; Tumor Molecular and Translational Medicine Lab, Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, P.R. China
| | - L U Yue
- Department of Oncology, Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, P.R. China; Tumor Molecular and Translational Medicine Lab, Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, P.R. China
| |
Collapse
|
14
|
Zhang X, Liu W, Yang H, Tan L, Ao L, Liu J, Cao J, Cui Z. Inhibition of PPARα attenuates vimentin phosphorylation on Ser-83 and collapse of vimentin filaments during exposure of rat Sertoli cells in vitro to DBP. Reprod Toxicol 2014; 50:11-8. [PMID: 25291543 DOI: 10.1016/j.reprotox.2014.09.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 09/24/2014] [Accepted: 09/25/2014] [Indexed: 12/18/2022]
Abstract
Dibutyl phthalate (DBP) is a peroxisome proliferator which can lead to germ cell loss from Sertoli cells. Collapse of vimentin filaments occurs in Sertoli cells after DBP exposure. Peroxisome proliferator activated receptor α (PPARα) is a key receptor which could be activated by DBP. The role of PPARα in this process was investigated. Results showed that, PPARα was activated in DBP-exposed Sertoli cells, GW6471 inhibited the activity of PPARα, phosphorylation level of vimentin and concentration of soluble vimentin was higher in DBP-treated Sertoli cells than GW6471+DBP-treated cells. These results suggest that PPARα directly or indirectly mediated phosphorylation of vimentin on Ser 83, and PPARα may play an important role in regulating the reorganization of vimentin filaments during exposure of Sertoli cells to DBP.
Collapse
Affiliation(s)
- Xi Zhang
- Toxicology Institute, College of Preventive Medicine, Third Military Medical University, No. 30, Gaotanyan Road, Shapingba District, Chongqing 400038, China.
| | - Wenbin Liu
- Toxicology Institute, College of Preventive Medicine, Third Military Medical University, No. 30, Gaotanyan Road, Shapingba District, Chongqing 400038, China.
| | - Huan Yang
- Toxicology Institute, College of Preventive Medicine, Third Military Medical University, No. 30, Gaotanyan Road, Shapingba District, Chongqing 400038, China.
| | - Lu Tan
- Toxicology Institute, College of Preventive Medicine, Third Military Medical University, No. 30, Gaotanyan Road, Shapingba District, Chongqing 400038, China.
| | - Lin Ao
- Toxicology Institute, College of Preventive Medicine, Third Military Medical University, No. 30, Gaotanyan Road, Shapingba District, Chongqing 400038, China.
| | - Jinyi Liu
- Toxicology Institute, College of Preventive Medicine, Third Military Medical University, No. 30, Gaotanyan Road, Shapingba District, Chongqing 400038, China.
| | - Jia Cao
- Toxicology Institute, College of Preventive Medicine, Third Military Medical University, No. 30, Gaotanyan Road, Shapingba District, Chongqing 400038, China.
| | - Zhihong Cui
- Toxicology Institute, College of Preventive Medicine, Third Military Medical University, No. 30, Gaotanyan Road, Shapingba District, Chongqing 400038, China.
| |
Collapse
|
15
|
Johnson-Kerner BL, Roth L, Greene JP, Wichterle H, Sproule DM. Giant axonal neuropathy: An updated perspective on its pathology and pathogenesis. Muscle Nerve 2014; 50:467-76. [DOI: 10.1002/mus.24321] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/16/2014] [Indexed: 12/15/2022]
Affiliation(s)
- Bethany L. Johnson-Kerner
- Project A.L.S./Jenifer Estess Laboratory for Stem Cell Research; Center for Motor Neuron Biology and Disease, Columbia Stem Cell Initiative, Columbia University College of Physicians and Surgeons; New York New York USA
| | - Lisa Roth
- Project A.L.S./Jenifer Estess Laboratory for Stem Cell Research; Center for Motor Neuron Biology and Disease, Columbia Stem Cell Initiative, Columbia University College of Physicians and Surgeons; New York New York USA
| | - J. Palmer Greene
- Project A.L.S./Jenifer Estess Laboratory for Stem Cell Research; Center for Motor Neuron Biology and Disease, Columbia Stem Cell Initiative, Columbia University College of Physicians and Surgeons; New York New York USA
| | - Hynek Wichterle
- Project A.L.S./Jenifer Estess Laboratory for Stem Cell Research; Center for Motor Neuron Biology and Disease, Columbia Stem Cell Initiative, Columbia University College of Physicians and Surgeons; New York New York USA
| | - Douglas M. Sproule
- Division of Pediatric Neurosciences, Department of Neurology; SMA Clinical Research Center, Columbia University Medical Center; Harkness Pavilion, HP-519, 180 Fort Washington Avenue New York New York 10032-3791 USA
| |
Collapse
|
16
|
Brown WS, Khalili JS, Rodriguez-Cruz TG, Lizee G, McIntyre BW. B-Raf regulation of integrin α4β1-mediated resistance to shear stress through changes in cell spreading and cytoskeletal association in T cells. J Biol Chem 2014; 289:23141-23153. [PMID: 24936068 DOI: 10.1074/jbc.m114.562918] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The regulation of integrin-mediated adhesion is of vital importance to adaptive and innate immunity. Integrins are versatile proteins and mediate T cell migration and trafficking by binding to extracellular matrix or other cells as well as initiating intracellular signaling cascades promoting survival or activation. The MAPK pathway is known to be downstream from integrins and to regulate survival, differentiation, and motility. However, secondary roles for canonical MAPK pathway members are being discovered. We show that chemical inhibition of RAF by sorafenib or shRNA-mediated knockdown of B-Raf reduces T cell resistance to shear stress to α4β1 integrin ligands vascular cell adhesion molecule 1 (VCAM-1) and fibronectin, whereas inhibition of MEK/ERK by U0126 had no effect. Microscopy showed that RAF inhibition leads to significant inhibition of T cell spreading on VCAM-1. The association of α4β1 integrin with the actin cytoskeleton was shown to be dependent on B-Raf activity or expression, whereas α4β1 integrin affinity for soluble VCAM-1 was not. These effects were shown to be specific for α4β1 integrin and not other integrins, such as α5β1 or LFA-1, or a variety of membrane proteins. We demonstrate a novel role for B-Raf in the selective regulation of α4β1 integrin-mediated adhesion.
Collapse
Affiliation(s)
- Wells S Brown
- Department of Immunology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 and
| | - Jahan S Khalili
- Department of Melanoma Medical Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - Tania G Rodriguez-Cruz
- Department of Melanoma Medical Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - Greg Lizee
- Department of Melanoma Medical Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - Bradley W McIntyre
- Department of Immunology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 and.
| |
Collapse
|
17
|
Pritchard AL, Hayward NK. Molecular pathways: mitogen-activated protein kinase pathway mutations and drug resistance. Clin Cancer Res 2013; 19:2301-9. [PMID: 23406774 DOI: 10.1158/1078-0432.ccr-12-0383] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Receptor tyrosine kinases are a diverse family of transmembrane proteins that can activate multiple pathways upon ligation of the receptor, one of which is the series of mitogen-activated protein kinase (MAPK) signaling cascades. The MAPK pathways play critical roles in a wide variety of cancer types, from hematologic malignancies to solid tumors. Aberrations include altered expression levels and activation states of pathway components, which can sometimes be attributable to mutations in individual members. The V600E mutation of BRAF was initially described in 2002 and has been found at particularly high frequency in melanoma and certain subtypes of colorectal cancer. In the relatively short time since this discovery, a family of drugs has been developed that specifically target this mutated BRAF isoform, which, after results from phase I/II and III clinical trials, was granted U.S. Food and Drug Administration approval in August 2011. Although these drugs produce clinically meaningful increases in progression-free and overall survival, due to acquired resistance they have not improved mortality rates. New drugs targeting other members of the MAPK pathways are in clinical trials or advanced stages of development. It is hoped that combination therapies of these new drugs in conjunction with BRAF inhibitors will counteract the mechanisms of resistance and provide cures. The clinical implementation of next-generation sequencing is leading to a greater understanding of the genetic architecture of tumors, along with acquired mechanisms of drug resistance, which will guide the development of tumor-specific inhibitors and combination therapies in the future.
Collapse
Affiliation(s)
- Antonia L Pritchard
- Oncogenomics Research Group, CBCRC Building, Queensland Institute of Medical Research, Herston, Brisbane, Queensland, Australia
| | | |
Collapse
|
18
|
Bonfiglio JJ, Inda C, Senin S, Maccarrone G, Refojo D, Giacomini D, Turck CW, Holsboer F, Arzt E, Silberstein S. B-Raf and CRHR1 internalization mediate biphasic ERK1/2 activation by CRH in hippocampal HT22 Cells. Mol Endocrinol 2013; 27:491-510. [PMID: 23371389 DOI: 10.1210/me.2012-1359] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
CRH is a key regulator of neuroendocrine, autonomic, and behavioral response to stress. CRH-stimulated CRH receptor 1 (CRHR1) activates ERK1/2 depending on intracellular context. In a previous work, we demonstrated that CRH activates ERK1/2 in limbic areas of the mouse brain (hippocampus and basolateral amygdala). ERK1/2 is an essential mediator of hippocampal physiological processes including emotional behavior, synaptic plasticity, learning, and memory. To elucidate the molecular mechanisms by which CRH activates ERK1/2 in hippocampal neurons, we used the mouse hippocampal cell line HT22. We document for the first time that ERK1/2 activation in response to CRH is biphasic, involving a first cAMP- and B-Raf-dependent early phase and a second phase that critically depends on CRHR1 internalization and β-arrestin2. By means of mass-spectrometry-based screening, we identified B-Raf-associated proteins that coimmunoprecipitate with endogenous B-Raf after CRHR1 activation. Using molecular and pharmacological tools, the functional impact of selected B-Raf partners in CRH-dependent ERK1/2 activation was dissected. These results indicate that 14-3-3 proteins, protein kinase A, and Rap1, are essential for early CRH-induced ERK1/2 activation, whereas dynamin and vimentin are required for the CRHR1 internalization-dependent phase. Both phases of ERK1/2 activation depend on calcium influx and are affected by calcium/calmodulin-dependent protein kinase II inactivation. Thus, this report describes the dynamics and biphasic nature of ERK1/2 activation downstream neuronal CRHR1 and identifies several new critical components of the CRHR1 signaling machinery that selectively controls the early and late phases of ERK1/2 activation, thus providing new potential therapeutic targets for stress-related disorders.
Collapse
Affiliation(s)
- Juan J Bonfiglio
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA), CONICET, Partner Institute of the Max Planck Society, Godoy Cruz 2390, C1425FQA Buenos Aires, Argentina
| | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Mussche S, De Paepe B, Smet J, Devreese K, Lissens W, Rasic VM, Murnane M, Devreese B, Van Coster R. Proteomic analysis in giant axonal neuropathy: new insights into disease mechanisms. Muscle Nerve 2012; 46:246-56. [PMID: 22806374 DOI: 10.1002/mus.23306] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
INTRODUCTION Giant axonal neuropathy (GAN) is a progressive hereditary disease that affects the peripheral and central nervous systems. It is characterized morphologically by aggregates of intermediate filaments in different tissues. Mutations have been reported in the gene that codes for gigaxonin. Nevertheless, the underlying molecular mechanism remains obscure. METHODS Cell lines from 4 GAN patients and 4 controls were analyzed by iTRAQ. RESULTS Among the dysregulated proteins were ribosomal protein L29, ribosomal protein L37, galectin-1, glia-derived nexin, and aminopeptidase N. Also, nuclear proteins linked to formin-binding proteins were found to be dysregulated. Although the major role of gigaxonin is reported to be degradation of cytoskeleton-associated proteins, the amount of 76 structural cytoskeletal proteins was unaltered. CONCLUSIONS Several of the dysregulated proteins play a role in cytoskeletal reorganization. Based on these findings, we speculate that disturbed cytoskeletal regulation is responsible for formation of aggregates of intermediate filaments.
Collapse
Affiliation(s)
- Silke Mussche
- Department of Pediatrics, Division of Pediatric Neurology and Metabolism, Ghent University Hospital, De Pintelaan 185, B-9000 Ghent, Belgium
| | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Vanden Berghe W, Sabbe L, Kaileh M, Haegeman G, Heyninck K. Molecular insight in the multifunctional activities of Withaferin A. Biochem Pharmacol 2012; 84:1282-91. [PMID: 22981382 DOI: 10.1016/j.bcp.2012.08.027] [Citation(s) in RCA: 144] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Revised: 08/29/2012] [Accepted: 08/30/2012] [Indexed: 12/11/2022]
Abstract
Herbal medicine which involves the use of plants for their medicinal value, dates as far back as the origin of mankind and demonstrates an array of applications including cardiovascular protection and anti-cancer activities, via antioxidant, anti-inflammatory and metabolic activities. Even today the popularity of medicinal herbs is still growing like in traditional medicines such as the Indian medicine, Ayurveda. One of the Ayurvedic medicinal plants is Withania somnifera Dunal, of which the important constituents are the withanolides. Among them, Withaferin A is one of the most bioactive compounds, exerting anti-inflammatory, pro-apoptotic but also anti-invasive and anti-angiogenic effects. In the context of modern pharmacology, a better insight in the underlying mechanism of the broad range of bioactivities exerted by Withaferin A is compulsory. Therefore, a lot of effort was made to explore the intracellular effects of Withaferin A and to characterize its target proteins. This review provides a decisive insight on the molecular basis of the health-promoting potential of Withaferin A.
Collapse
Affiliation(s)
- Wim Vanden Berghe
- Laboratory of Eukaryotic Gene Expression and Signal Transduction (LEGEST), Department of Physiology, Ghent University, Gent, Belgium
| | | | | | | | | |
Collapse
|
21
|
Kanakkanthara A, Rawson P, Northcote PT, Miller JH. Acquired resistance to peloruside A and laulimalide is associated with downregulation of vimentin in human ovarian carcinoma cells. Pharm Res 2012; 29:3022-32. [PMID: 22584948 DOI: 10.1007/s11095-012-0773-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Accepted: 04/30/2012] [Indexed: 11/26/2022]
Abstract
PURPOSE Acquired β-tubulin alterations in human ovarian carcinoma 1A9 cells were previously shown to confer resistance to the microtubule stabilizing agents peloruside A (PLA) and laulimalide (LAU). We examined the proteome of resistant cells to see what other protein changes occurred as a result of the acquired drug resistance. METHODS Two-dimensional differential in-gel electrophoresis was performed to explore differentially expressed proteins in the resistant 1A9-R1 (R1) and 1A9-L4 (L4) cells. The proteins on the gels were identified by MALDI-TOF MS, and altered protein abundance was confirmed by Western blotting and immunocytochemistry. Vimentin expression was restored in vimentin-deficient L4 cells by transfecting a full-length human vimentin cDNA, and sensitivity to PLA and LAU were tested using an MTT cell proliferation assay. RESULTS Proteomic analysis identified several proteins that were significantly altered in the resistant cells relative to the parental 1A9 cells. Using Western blotting and immunocytochemistry, a decreased vimentin abundance in the L4 cells was validated. Vimentin levels were unchanged in PLA-resistant R1 cells and paclitaxel/epothilone-resistant derivatives of 1A9 cells. Vimentin cDNA transfection into L4 cells partially restored PLA and LAU sensitivity. CONCLUSIONS Downregulation of vimentin contributes to the resistance of 1A9 cells to the microtubule stabilizing agents, PLA and LAU.
Collapse
Affiliation(s)
- Arun Kanakkanthara
- Centre for Biodiscovery, Victoria University of Wellington, PO Box 600, Wellington, 6140, New Zealand
| | | | | | | |
Collapse
|
22
|
Helfand BT, Mendez MG, Murthy SNP, Shumaker DK, Grin B, Mahammad S, Aebi U, Wedig T, Wu YI, Hahn KM, Inagaki M, Herrmann H, Goldman RD. Vimentin organization modulates the formation of lamellipodia. Mol Biol Cell 2011; 22:1274-89. [PMID: 21346197 PMCID: PMC3078081 DOI: 10.1091/mbc.e10-08-0699] [Citation(s) in RCA: 201] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The disassembly and withdrawal of vimentin intermediate filaments (VIF) from the plasma membrane induces membrane ruffling and the formation of a lamellipodium. Conversely, lamellipodium formation is inhibited when VIF are present. Vimentin intermediate filaments (VIF) extend throughout the rear and perinuclear regions of migrating fibroblasts, but only nonfilamentous vimentin particles are present in lamellipodial regions. In contrast, VIF networks extend to the entire cell periphery in serum-starved or nonmotile fibroblasts. Upon serum addition or activation of Rac1, VIF are rapidly phosphorylated at Ser-38, a p21-activated kinase phosphorylation site. This phosphorylation of vimentin is coincident with VIF disassembly at and retraction from the cell surface where lamellipodia form. Furthermore, local induction of photoactivatable Rac1 or the microinjection of a vimentin mimetic peptide (2B2) disassemble VIF at sites where lamellipodia subsequently form. When vimentin organization is disrupted by a dominant-negative mutant or by silencing, there is a loss of polarity, as evidenced by the formation of lamellipodia encircling the entire cell, as well as reduced cell motility. These findings demonstrate an antagonistic relationship between VIF and the formation of lamellipodia.
Collapse
Affiliation(s)
- Brian T Helfand
- Department of Urology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Bonfiglio JJ, Maccarrone G, Rewerts C, Holsboer F, Arzt E, Turck CW, Silberstein S. Characterization of the B-Raf interactome in mouse hippocampal neuronal cells. J Proteomics 2010; 74:186-98. [PMID: 21055488 DOI: 10.1016/j.jprot.2010.10.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2010] [Revised: 10/18/2010] [Accepted: 10/20/2010] [Indexed: 01/13/2023]
Abstract
B-Raf links a variety of extracellular stimuli downstream of cell surface receptors, constituting a determining factor in the ability of neurons to activate ERK. A detailed study of the B-Raf interactome is necessary to clarify the intricacy of B-Raf-dependent signal transduction. We used a mouse hippocampal cell line (HT22) that expresses B-Raf at high levels, to identify B-Raf associated proteins under endogenous expression conditions, avoiding artificial interactions from overexpression studies. We used stringent procedures to co-immunoprecipitate proteins that specifically associate with endogenous B-Raf with the help of gel electrophoresis separation and off-line LC-MALDI-MS/MS proteomic analysis. Our stringent protein identification criteria allowed confident identification of B-Raf interacting proteins under non-stimulating conditions. The presence of previously reported B-Raf interactors among the list of proteins identified confirms the quality of proteomic data. We identified tubulin and actin as B-Raf interactors for the first time, among structural and accessory proteins of cell cytoskeleton, molecular chaperones (Hsc70, GRP78), and cellular components involved in aspects of mRNA metabolism and translation. Interactions were validated in HT22 cells and in the neuronal cell line Neuro-2a providing further evidence that the identified proteins are B-Raf interactors, which constitute a basis for understanding MAPK pathway regulation in neurons.
Collapse
Affiliation(s)
- Juan J Bonfiglio
- Laboratorio de Fisiología y Biología Molecular, Departamento de Fisiología y Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales (FCEN), Universidad de Buenos Aires, IFIBYNE-CONICET, Buenos Aires, Argentina
| | | | | | | | | | | | | |
Collapse
|
24
|
Zeindl-Eberhart E, Liebmann S, Jungblut PR, Mattow J, Schmid M, Kerler R, Rabes HM. Influence of RET/PTC1 and RET/PTC3 oncoproteins in radiation-induced papillary thyroid carcinomas on amounts of cytoskeletal protein species. Amino Acids 2010; 41:415-25. [PMID: 20839015 DOI: 10.1007/s00726-010-0733-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2010] [Accepted: 08/26/2010] [Indexed: 10/19/2022]
Abstract
Radiation-induced human papillary thyroid carcinomas (PTCs) show a high prevalence of fusions of the RET proto-oncogene to heterologous genes H4 (RET/PTC1) and ELE1 (RET/PTC3), respectively. In contrast to the normal membrane-bound RET protein, aberrant RET fusion proteins are constitutively active oncogenic cytosolic proteins that can lead to malignant transformation of thyroid epithelia. To detect specific tumor-associated protein changes that reflect the effect of RET/PTC fusion proteins, we analyzed normal thyroid tissues, thyroid tumors of the RET/PTC1 and RET/PTC3 type and their respective lymph node metastases by a combination of high-resolution two-dimensional electrophoresis and matrix-assisted laser desorption/ionization-mass spectrometry. PTCs without RET rearrangements served as controls. Several cytoskeletal protein species showed quantitative changes in tumors and lymph node metastases harboring RET/PTC1 or RET/PTC3. We observed prominent C-terminal actin fragments assumedly generated by protease cleavages induced due to enhanced amounts of the active actin-binding protein cofilin-1. In addition, three truncated vimentin species, one of which was proven to be headless, were shown to be highly abundant in tumors and metastases of both RET/PTC types. The observed protein changes are closely connected with the constitutive activation of RET-rearranged oncoproteins and reflect the importance to elucidate disease-related typical signatures on the protein species level.
Collapse
Affiliation(s)
- Evelyn Zeindl-Eberhart
- Institute of Pathology, Ludwig-Maximilians-University of Munich, Thalkirchner Strasse 36, 80337, Munich, Germany.
| | | | | | | | | | | | | |
Collapse
|
25
|
Lahat G, Zhu QS, Huang KL, Wang S, Bolshakov S, Liu J, Torres K, Langley RR, Lazar AJ, Hung MC, Lev D. Vimentin is a novel anti-cancer therapeutic target; insights from in vitro and in vivo mice xenograft studies. PLoS One 2010; 5:e10105. [PMID: 20419128 PMCID: PMC2855704 DOI: 10.1371/journal.pone.0010105] [Citation(s) in RCA: 154] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2009] [Accepted: 03/03/2010] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Vimentin is a ubiquitous mesenchymal intermediate filament supporting mechano-structural integrity of quiescent cells while participating in adhesion, migration, survival, and cell signaling processes via dynamic assembly/disassembly in activated cells. Soft tissue sarcomas and some epithelial cancers exhibiting "epithelial to mesenchymal transition" phenotypes express vimentin. Withaferin-A, a naturally derived bioactive compound, may molecularly target vimentin, so we sought to evaluate its effects on tumor growth in vitro and in vivo thereby elucidating the role of vimentin in drug-induced responses. METHODS AND FINDINGS Withaferin-A elicited marked apoptosis and vimentin cleavage in vimentin-expressing tumor cells but significantly less in normal mesenchymal cells. This proapoptotic response was abrogated after vimentin knockdown or by blockade of caspase-induced vimentin degradation via caspase inhibitors or overexpression of mutated caspase-resistant vimentin. Pronounced anti-angiogenic effects of Withaferin-A were demonstrated, with only minimal effects seen in non-proliferating endothelial cells. Moreover, Withaferin-A significantly blocked soft tissue sarcoma growth, local recurrence, and metastasis in a panel of soft tissue sarcoma xenograft experiments. Apoptosis, decreased angiogenesis, and vimentin degradation were all seen in Withaferin-A treated specimens. CONCLUSIONS In light of these findings, evaluation of Withaferin-A, its analogs, or other anti-vimentin therapeutic approaches in soft tissue sarcoma and "epithelial to mesenchymal transition" clinical contexts is warranted.
Collapse
Affiliation(s)
- Guy Lahat
- Department of Surgical Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America
- Sarcoma Research Center, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America
| | - Quan-Sheng Zhu
- Department of Surgical Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America
- Sarcoma Research Center, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America
| | - Kai-Lieh Huang
- Sarcoma Research Center, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America
- Department of Cancer Biology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America
| | - Suizhao Wang
- Department of Surgical Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America
- Sarcoma Research Center, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America
| | - Svetlana Bolshakov
- Department of Surgical Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America
- Sarcoma Research Center, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America
| | - Jeffery Liu
- Department of Surgical Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America
- Sarcoma Research Center, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America
| | - Keila Torres
- Department of Surgical Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America
- Sarcoma Research Center, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America
| | - Robert R. Langley
- Department of Cancer Biology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America
| | - Alexander J. Lazar
- Sarcoma Research Center, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America
- Department of Pathology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America
| | - Mien Chie Hung
- Department of Molecular and Cellular Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America
| | - Dina Lev
- Sarcoma Research Center, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America
- Department of Cancer Biology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America
| |
Collapse
|
26
|
Sathishkumar K, Yallampalli U, Elkins R, Yallampalli C. Raf-1 kinase regulates smooth muscle contraction in the rat mesenteric arteries. J Vasc Res 2010; 47:384-98. [PMID: 20110729 DOI: 10.1159/000277726] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2009] [Accepted: 09/04/2009] [Indexed: 01/30/2023] Open
Abstract
We investigated the potential role of Raf-1 kinase in mesenteric arterial contraction. Inhibitors of Raf-1 kinase, GW5074, L779450 and ZM 336372 reversed phenylephrine (PE)-induced mesenteric vascular contraction. Studies in vivo in rats showed that GW5074 inhibited PE-induced increase in mean arterial pressure in adult female Sprague-Dawley rats. Isometric tension studies in mesenteric arteries of rats showed that GW5074 did not change the KCl-evoked contraction but significantly inhibited the contractions to PE, 5-HT, U46619, endothelin 1, angiotensin II and phorbol 12, 13-dibutyrate (PDBu). In mesenteric vascular smooth muscle cells (VSMCs), PE stimulated increase in Raf-1 phosphorylation which was inhibited by GW5074. Measurement of [Ca(2+)](i) with Fura-2 showed that GW5074-mediated inhibition of PE-induced contraction was not associated with decreases in [Ca(2+)](i). VSMCs treated with PE exhibited higher levels of the contractile proteins, p-MYPT1 and p-MLC(20), which was inhibited by GW5074. Similarly, PDBu induced increases in phosphorylation of Raf-1, MLC(20) and MYPT1 and this was inhibited by GW5074. However, GW5074 did not have any significant effect on PE/PDBu-induced MEK/ERK activation. The results indicate that Raf-1 kinase plays an important role in the regulation of vascular contractility through regulation of calcium sensitization.
Collapse
Affiliation(s)
- Kunju Sathishkumar
- Department of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston, Tex. 77555-1062, USA
| | | | | | | |
Collapse
|
27
|
Hyperhomocysteinemia selectively alters expression and stoichiometry of intermediate filament and induces glutamate‐ and calcium‐mediated mechanisms in rat brain during development. Int J Dev Neurosci 2009; 28:21-30. [DOI: 10.1016/j.ijdevneu.2009.10.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Accepted: 10/02/2009] [Indexed: 01/17/2023] Open
|
28
|
Eriksson JE, Dechat T, Grin B, Helfand B, Mendez M, Pallari HM, Goldman RD. Introducing intermediate filaments: from discovery to disease. J Clin Invest 2009; 119:1763-71. [PMID: 19587451 DOI: 10.1172/jci38339] [Citation(s) in RCA: 301] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
It took more than 100 years before it was established that the proteins that form intermediate filaments (IFs) comprise a unified protein family, the members of which are ubiquitous in virtually all differentiated cells and present both in the cytoplasm and in the nucleus. However, during the past 2 decades, knowledge regarding the functions of these structures has been expanding rapidly. Many disease-related roles of IFs have been revealed. In some cases, the molecular mechanisms underlying these diseases reflect disturbances in the functions traditionally assigned to IFs, i.e., maintenance of structural and mechanical integrity of cells and tissues. However, many disease conditions seem to link to the nonmechanical functions of IFs, many of which have been defined only in the past few years.
Collapse
Affiliation(s)
- John E Eriksson
- Department of Biology, Abo Akademi University, Turku, Finland.
| | | | | | | | | | | | | |
Collapse
|
29
|
Asami Y, Mori M, Koshino H, Sekiyama Y, Teruya T, Simizu S, Usui T, Osada H. A cell-based screening to detect inhibitors of BRAF signaling pathway. J Antibiot (Tokyo) 2009; 62:105-7. [DOI: 10.1038/ja.2008.17] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
|
30
|
Persson O, Brynnel U, Levander F, Widegren B, Salford LG, Krogh M. Proteomic expression analysis and comparison of protein and mRNA expression profiles in human malignant gliomas. Proteomics Clin Appl 2008; 3:83-94. [DOI: 10.1002/prca.200800086] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2008] [Indexed: 12/12/2022]
|
31
|
Nawarak J, Huang-Liu R, Kao SH, Liao HH, Sinchaikul S, Chen ST, Cheng SL. Proteomics analysis of A375 human malignant melanoma cells in response to arbutin treatment. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2008; 1794:159-67. [PMID: 18996230 DOI: 10.1016/j.bbapap.2008.09.023] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2008] [Revised: 09/12/2008] [Accepted: 09/29/2008] [Indexed: 12/23/2022]
Abstract
Although the toxicogenomics of A375 human malignant melanoma cells treated with arbutin have been elucidated using DNA microarray, the proteomics of the cellular response to this compound are still poorly understood. In this study, we performed proteomic analyses to investigate the anticancer effect of arbutin on the protein expression profile in A375 cells. After treatment with arbutin (8 microg/ml) for 24, 48 and 72 h, the proteomic profiles of control and arbutin-treated A375 cells were compared, and 26 differentially expressed proteins (7 upregulated and 19 downregulated proteins) were identified by MALDI-Q-TOF MS and MS/MS. Among these proteins, 13 isoforms of six identical proteins were observed. Bioinformatic tools were used to search for protein function and to predict protein interactions. The interaction network of 14 differentially expressed proteins was found to be correlated with the downstream regulation of p53 tumor suppressor and cell apoptosis. In addition, three upregulated proteins (14-3-3G, VDAC-1 and p53) and five downregulated proteins (ENPL, ENOA, IMDH2, PRDX1 and VIME) in arbutin-treated A375 cells were validated by RT-PCR analysis. These proteins were found to play important roles in the suppression of cancer development.
Collapse
Affiliation(s)
- Jiraporn Nawarak
- Institute of Biological Chemistry and Genomics Research Center, Academia Sinica, Taipei 11529, Taiwan
| | | | | | | | | | | | | |
Collapse
|
32
|
Congenital hypothyroidism is associated with intermediate filament misregulation, glutamate transporters down-regulation and MAPK activation in developing rat brain. Neurotoxicology 2008; 29:1092-9. [PMID: 18845185 DOI: 10.1016/j.neuro.2008.09.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2007] [Revised: 09/10/2008] [Accepted: 09/10/2008] [Indexed: 12/17/2022]
Abstract
Developmental thyroid hormone (TH) deficiency leads to mental retardation and neurological deficits in humans. In this study, congenital hypothyroidism was induced in rats by adding 0.05% 6-propyl-2-thiouracil in the drinking water during gestation and suckling period. This treatment induced hyperphosphorylation of neurofilaments, the neuronal intermediate filament (IF) proteins, of heavy, medium and low molecular weight (NF-H, NF-M and NF-L, respectively) without altering the phosphorylation level of astrocyte IF proteins, glial fibrillary acidic protein (GFAP) and vimentin in cerebral cortex of rats. NF-H was hyperphosphorylated on KSP repeats in the carboxy-terminal tail domain. Furthermore, the immunocontent of GFAP and NF subunits was down-regulated, while vimentin was unaltered both in tissue homogenate and in cytoskeletal fraction of hypothyroid animals. Moreover, we verified the immunocontent of astrocyte glutamate/aspartate transporter (GLAST) and glutamate transporter-1 (GLT-1) as well as activation of mitogen-activated protein kinases (MAPKs) in hypothyroid rats. Results showed that hypothyroidism is associated with decreased GLAST and GLT-1 immunocontent. Additionally, we demonstrated increased extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation without altering Jun N-terminal kinase (JNK) and p38(MAPK) phosphorylation. However, total JNK levels were down-regulated. Taken together, these results suggest that the thyroid status could modulate the integrity of neuronal cytoskeleton acting on the endogenous NF-associated phosphorylating system and that such effect could be related to glutamate-induced excitotoxicity, as well as ERK1/2 and JNK modulation. These events could be somehow related to the neurological dysfunction described in hypothyroidism.
Collapse
|
33
|
Nawarak J, Huang-Liu R, Kao SH, Liao HH, Sinchaikul S, Chen ST, Cheng SL. Proteomics analysis of kojic acid treated A375 human malignant melanoma cells. J Proteome Res 2008; 7:3737-46. [PMID: 18630942 DOI: 10.1021/pr7008737] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Although the toxicogenomics of kojic acid treated A375 human malignant melanoma cells has been elucidated, the proteomics of cellular response is still poorly understood. We performed proteomic analysis to investigate the anticancer effect of kojic acid on protein expression profile in A375 cells. A375 cells were treated with kojic acid at 8 microg/mL for 24, 48, and 72 h. With the use of 2-D PAGE and MALDI-Q-TOF MS and MS/MS analyses, proteomic profiles of A375 cells between control and kojic acid treatment were compared, and 30 differentially expressed proteins, containing 2 up-regulated proteins and 28 down-regulated proteins, were identified. Among these proteins, 17 isoforms of 5 identical proteins were observed and 11 chaperone proteins showed the high proportion of protein spots with 36.7% of total proteins. Bioinformatic tools were used to search for protein function and prediction of protein interaction. Sixteen differentially expressed proteins exhibited interaction network linked to the downstream regulations of p53 tumor suppressor and cell apoptosis, which may lead to suppress the melanogenesis and tumorigenesis of kojic acid treated A375 cells. In addition, GRP75, VIME and 2AAA were validated by Western blot analysis, whereas GRP75, 2AAA, HS90B, ENPL and KPYM were validated by RT-PCR. Therefore, these proteins play the important roles in cancer progression and may be potential biomarkers that are useful for diagnostic and therapeutic applications of malignant melanoma cancer.
Collapse
Affiliation(s)
- Jiraporn Nawarak
- Institute of Biological Chemistry and Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | | | | | | | | | | | | |
Collapse
|
34
|
Hyder CL, Pallari HM, Kochin V, Eriksson JE. Providing cellular signposts - Post-translational modifications of intermediate filaments. FEBS Lett 2008; 582:2140-8. [DOI: 10.1016/j.febslet.2008.04.064] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2008] [Revised: 04/29/2008] [Accepted: 04/30/2008] [Indexed: 10/22/2022]
|
35
|
Abstract
Over the past 5 years, the Raf kinase family has emerged as a promising target for protein-directed cancer therapy development. The goal of this review is to first provide a concise summary of the data validating Raf proteins as high-interest therapeutic targets. The authors then outline the mode of action of Raf kinases, emphasizing how Raf activities and protein interactions suggest specific approaches to inhibiting Raf. The authors then summarize the set of drugs, antisense reagents and antibodies available or in development for therapeutically targeting Raf or Raf-related proteins, as well as existing strategies combining these and other therapeutic agents. Finally, the authors discuss recent results from systems biology analyses that have the potential to increasingly guide the intelligent selection of combination therapies involving Raf-targeting agents and other therapeutics.
Collapse
|
36
|
Leicht DT, Balan V, Kaplun A, Singh-Gupta V, Kaplun L, Dobson M, Tzivion G. Raf kinases: function, regulation and role in human cancer. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2007; 1773:1196-212. [PMID: 17555829 PMCID: PMC1986673 DOI: 10.1016/j.bbamcr.2007.05.001] [Citation(s) in RCA: 205] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2006] [Revised: 05/01/2007] [Accepted: 05/02/2007] [Indexed: 12/25/2022]
Abstract
The Ras-Raf-MAPK pathway regulates diverse physiological processes by transmitting signals from membrane based receptors to various nuclear, cytoplasmic and membrane-bound targets, coordinating a large variety of cellular responses. Function of Raf family kinases has been shown to play a role during organism development, cell cycle regulation, cell proliferation and differentiation, cell survival and apoptosis and many other cellular and physiological processes. Aberrations along the Ras-Raf-MAPK pathway play an integral role in various biological processes concerning human health and disease. Overexpression or activation of the pathway components is a common indicator in proliferative diseases such as cancer and contributes to tumor initiation, progression and metastasis. In this review, we focus on the physiological roles of Raf kinases in normal and disease conditions, specifically cancer, and the current thoughts on Raf regulation.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Guri Tzivion
- To whom correspondence should be addressed: Karmanos Cancer Institute, Wayne State University, 4100 John R., HWCRC 716, Detroit, MI 48201, Tel: 313-576-8311, Fax: 313-576-8308, E-mail:
| |
Collapse
|
37
|
Ivaska J, Pallari HM, Nevo J, Eriksson JE. Novel functions of vimentin in cell adhesion, migration, and signaling. Exp Cell Res 2007; 313:2050-62. [PMID: 17512929 DOI: 10.1016/j.yexcr.2007.03.040] [Citation(s) in RCA: 544] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2007] [Revised: 03/20/2007] [Accepted: 03/26/2007] [Indexed: 02/07/2023]
Abstract
Vimentin is the major intermediate filament (IF) protein of mesenchymal cells. It shows dynamically altered expression patterns during different developmental stages and high sequence homology throughout all vertebrates, suggesting that the protein is physiologically important. Still, until recently, the real tasks of vimentin have been elusive, primarily because the vimentin-deficient mice were originally characterized as having a very mild phenotype. Recent studies have revealed several key functions for vimentin that were not obvious at first sight. Vimentin emerges as an organizer of a number of critical proteins involved in attachment, migration, and cell signaling. The highly dynamic and complex phosphorylation of vimentin seems to be a likely regulator mechanism for these functions. The implicated novel vimentin functions have broad ramifications into many different aspects of cell physiology, cellular interactions, and organ homeostasis.
Collapse
Affiliation(s)
- Johanna Ivaska
- VTT Medical Biotechnology, Itäinen Pitkäkatu 4C, FI-20520 Turku, Finland
| | | | | | | |
Collapse
|
38
|
Kramerov AA, Saghizadeh M, Pan H, Kabosova A, Montenarh M, Ahmed K, Penn JS, Chan CK, Hinton DR, Grant MB, Ljubimov AV. Expression of protein kinase CK2 in astroglial cells of normal and neovascularized retina. THE AMERICAN JOURNAL OF PATHOLOGY 2006; 168:1722-36. [PMID: 16651637 PMCID: PMC1606582 DOI: 10.2353/ajpath.2006.050533] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We previously documented protein kinase CK2 involvement in retinal neovascularization. Here we describe retinal CK2 expression and combined effects of CK2 inhibitors with the somatostatin analog octreotide in a mouse model of oxygen-induced retinopathy (OIR). CK2 expression in human and rodent retinas with and without retinopathy and in astrocytic and endothelial cultures was examined by immunohistochemistry, Western blotting, and reverse transcriptase-polymerase chain reaction. A combination of CK2 inhibitors, emodin or 4,5,6,7-tetrabromobenzotriazole, with octreotide was injected intraperitoneally from postnatal (P) day P11 to P17 to block mouse OIR. All CK2 subunits (alpha, alpha', beta) were expressed in retina, and a novel CK2alpha splice variant was detected by reverse transcriptase-polymerase chain reaction. CK2 antibodies primarily reacted with retinal astrocytes, and staining was increased around new intraretinal vessels in mouse OIR and rat retinopathy of prematurity, whereas preretinal vessels were negative. Cultured astrocytes showed increased perinuclear CK2 staining compared to endothelial cells. In the OIR model, CK2 mRNA expression increased modestly on P13 but not on P17. Octreotide combined with emodin or 4,5,6,7-tetrabromobenzotriazole blocked mouse retinal neovascularization more efficiently than either compound alone. Based on its retinal localization, CK2 may be considered a new immunohistochemical astrocytic marker, and combination of CK2 inhibitors and octreotide may be a promising future treatment for proliferative retinopathies.
Collapse
Affiliation(s)
- Andrei A Kramerov
- Ophthalmology Research Laboratories, Cedars-Sinai Medical Center, University of California at Los Angeles School of Medicine, 90048, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Beeram M, Patnaik A, Rowinsky EK. Raf: A Strategic Target for Therapeutic Development Against Cancer. J Clin Oncol 2005; 23:6771-90. [PMID: 16170185 DOI: 10.1200/jco.2005.08.036] [Citation(s) in RCA: 215] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The mitogen-activated protein kinase (MAPK) signaling pathway plays a critical role in transmitting proliferative signals generated by cell surface receptors and cytoplasmic signaling elements to the nucleus. Several important signaling elements of the MAPK pathway, particularly Ras and Raf, are encoded by oncogenes, and as such, their structures and functions can be modified, rendering them constitutively active. Because the MAPK pathway is dysregulated in a notable proportion of human malignancies, many of its aberrant and critical components represent strategic targets for therapeutic development against cancer. Raf, which is an essential serine/threonine kinase constituent of the MAPK pathway and a downstream effector of the central signal transduction mediator Ras, is activated in a wide range of human malignancies by aberrant signaling upstream of the protein (eg, growth factor receptors and mutant Ras) and activating mutations of the protein itself, both of which confer a proliferative advantage. Three isoforms of Raf have been identified, and therapeutics targeting Raf, including small-molecule inhibitors and antisense oligodeoxyribonucleotides (ASON), are undergoing clinical evaluation. The outcomes of these investigations may have far-reaching implications in the management of many types of human cancer. This review outlines the structure and diverse functions of Raf, the rationale for targeting Raf as a therapeutic strategy against cancer, and the present status of various therapeutic approaches including ASONs and small molecules, particularly sorafenib (BAY 43-9006).
Collapse
Affiliation(s)
- Muralidhar Beeram
- University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | | | | |
Collapse
|
40
|
Ehrenreiter K, Piazzolla D, Velamoor V, Sobczak I, Small JV, Takeda J, Leung T, Baccarini M. Raf-1 regulates Rho signaling and cell migration. ACTA ACUST UNITED AC 2005; 168:955-64. [PMID: 15753127 PMCID: PMC2171799 DOI: 10.1083/jcb.200409162] [Citation(s) in RCA: 157] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Raf kinases relay signals inducing proliferation, differentiation, and survival. The Raf-1 isoform has been extensively studied as the upstream kinase linking Ras activation to the MEK/ERK module. Recently, however, genetic experiments have shown that Raf-1 plays an essential role in counteracting apoptosis, and that it does so independently of its ability to activate MEK. By conditional gene ablation, we now show that Raf-1 is required for normal wound healing in vivo and for the migration of keratinocytes and fibroblasts in vitro. Raf-1-deficient cells show a symmetric, contracted appearance, characterized by cortical actin bundles and by a disordered vimentin cytoskeleton. These defects are due to the hyperactivity and incorrect localization of the Rho-effector Rok-alpha to the plasma membrane. Raf-1 physically associates with Rok-alpha in wild-type (WT) cells, and reintroduction of either WT or kinase-dead Raf-1 in knockout fibroblasts rescues their defects in shape and migration. Thus, Raf-1 plays an essential, kinase-independent function as a spatial regulator of Rho downstream signaling during migration.
Collapse
Affiliation(s)
- Karin Ehrenreiter
- Department of Microbiology and Genetics, Max F. Perutz Laboratories, University Departments at the Vienna Biocenter, 1030 Vienna, Austria
| | | | | | | | | | | | | | | |
Collapse
|
41
|
Li H, Ye X, Mahanivong C, Bian D, Chun J, Huang S. Signaling mechanisms responsible for lysophosphatidic acid-induced urokinase plasminogen activator expression in ovarian cancer cells. J Biol Chem 2005; 280:10564-71. [PMID: 15653692 DOI: 10.1074/jbc.m412152200] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Lysophosphatidic acid (LPA) enhances urokinase plasminogen activator (uPA) expression in ovarian cancer cells; however, the molecular mechanisms responsible for this event have not been investigated. In this study, we used the invasive ovarian cancer SK-OV-3 cell line to explore the signaling molecules and pathways essential for LPA-induced uPA up-regulation. With the aid of specific inhibitors and dominant negative forms of signaling molecules, we determined that the G(i)-associated pathway mediates this LPA-induced event. Moreover, constitutively active H-Ras and Raf-1-activating H-Ras mutant enhance uPA expression, whereas dominant negative H-Ras and Raf-1 block LPA-induced uPA up-regulation, suggesting that the Ras-Raf pathway works downstream of G(i) to mediate this LPA-induced process. Surprisingly, dominant negative MEK1 or Erk2 displays only marginal inhibitory effect on LPA-induced uPA up-regulation, suggesting that a signaling pathway distinct from Raf-MEK1/2-Erk is the prominent pathway responsible for this process. In this report, we demonstrate that LPA activates NF-kappaB in a Ras-Raf-dependent manner and that blocking NF-kappaB activation with either non-phosphorylable IkappaB or dominant negative IkappaB kinase abolished LPA-induced uPA up-regulation and uPA promoter activation. Furthermore, introducing mutations to knock out the NF-kappaB binding site of the uPA promoter results in over 80% reduction in LPA-induced uPA promoter activation, whereas this activity is largely intact with the promoter containing mutations in the AP1 binding sites. Thus these results suggest that the G(i)-Ras-Raf-NF-kappaB signaling cascade is responsible for LPA-induced uPA up-regulation in ovarian cancer cells.
Collapse
Affiliation(s)
- Hongbin Li
- Department of Immunology and Molecular Biology, The Scripps Research Institute, 10550 N. Torrey Pines Rd., La Jolla, California 92037, USA
| | | | | | | | | | | |
Collapse
|
42
|
Abstract
Keratins 8 and 18 (K8/18) heteropolymers may regulate cell signaling via the known K18 association with 14-3-3 proteins and 14-3-3 association with Raf-1 kinase. We characterized Raf–keratin–14-3-3 associations and show that Raf associates directly with K8, independent of Raf kinase activity or Ras–Raf interaction, and that K18 is a Raf physiologic substrate. Raf activation during oxidative and toxin exposure in cultured cells and animals disrupt keratin–Raf association in a phosphorylation-dependent manner. Mutational analysis showed that 14-3-3 residues that are essential for Raf binding also regulate 14-3-3–keratin association. Similarly, Raf phosphorylation sites that are important for binding to 14-3-3 are also essential for Raf binding to K8/18. Therefore, keratins may modulate some aspects of Raf signaling under basal conditions via sequestration by K8, akin to Raf–14-3-3 binding. Keratin-bound Raf kinase is released upon Raf hyperphosphorylation and activation during oxidative and other stresses.
Collapse
Affiliation(s)
- Nam-On Ku
- Department of Medicine, VA Palo Alto Medical Center, 3801 Miranda Ave., 154J, Palo Alto, CA 94304, USA
| | | | | |
Collapse
|
43
|
Eriksson JE, He T, Trejo-Skalli AV, Härmälä-Braskén AS, Hellman J, Chou YH, Goldman RD. Specific in vivo phosphorylation sites determine the assembly dynamics of vimentin intermediate filaments. J Cell Sci 2004. [DOI: 10.1242/jcs.00906 jcs.00906] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Intermediate filaments (IFs) continuously exchange between a small, depolymerized fraction of IF protein and fully polymerized IFs. To elucidate the possible role of phosphorylation in regulating this equilibrium, we disrupted the exchange of phosphate groups by specific inhibition of dephosphorylation and by specific phosphorylation and site-directed mutagenesis of two of the major in vivo phosphorylation sites determined in this study. Inhibition of type-1 (PP1) and type-2A (PP2A) protein phosphatases in BHK-21 fibroblasts with calyculin-A, induced rapid vimentin phosphorylation in concert with disassembly of the IF polymers into soluble tetrameric vimentin oligomers. This oligomeric composition corresponded to the oligopeptides released by cAMP-dependent kinase (PKA) following in vitro phosphorylation. Characterization of the 32P-labeled vimentin phosphopeptides, demonstrated Ser-4, Ser-6, Ser-7, Ser-8, Ser-9, Ser-38, Ser-41, Ser-71, Ser-72, Ser-418, Ser-429, Thr-456, and Ser-457 as significant in vivo phosphorylation sites. A number of the interphase-specific high turnover sites were shown to be in vitro phosphorylation sites for PKA and protein kinase C (PKC). The effect of presence or absence of phosphate groups on individual subunits was followed in vivo by microinjecting PKA-phosphorylated (primarily S38 and S72) and mutant vimentin (S38:A, S72:A), respectively. The PKA-phosphorylated vimentin showed a clearly decelerated filament formation in vivo, whereas obstruction of phosphorylation at these sites by site-directed mutagenesis had no significant effect on the incorporation rates of subunits into assembled polymers. Taken together, our results suggest that elevated phosphorylation regulates IF assembly in vivo by changing the equilibrium constant of subunit exchange towards a higher off-rate.
Collapse
Affiliation(s)
- John E. Eriksson
- Department of Biology, Laboratory of Animal Physiology, University of Turku, Science Building 1, FIN-20014 Turku, Finland
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, POB 123, FIN-20521 Turku, Finland
| | - Tao He
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, POB 123, FIN-20521 Turku, Finland
- Department of Biochemistry, Åbo Akademi University, FIN-20521 Turku, Finland
- Turku Graduate School of Biomedical Sciences, Kiinanmyllynkatu 13, FIN-20520, Turku, Finland
| | - Amy V. Trejo-Skalli
- Department of Cell, Molecular, and Structural Biology, Northwestern University Medical School, 303 E. Chicago Avenue, Chicago, IL-60611-3008, USA
| | - Ann-Sofi Härmälä-Braskén
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, POB 123, FIN-20521 Turku, Finland
- Department of Biochemistry, Åbo Akademi University, FIN-20521 Turku, Finland
| | - Jukka Hellman
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, POB 123, FIN-20521 Turku, Finland
| | - Ying-Hao Chou
- Department of Cell, Molecular, and Structural Biology, Northwestern University Medical School, 303 E. Chicago Avenue, Chicago, IL-60611-3008, USA
| | - Robert D. Goldman
- Department of Cell, Molecular, and Structural Biology, Northwestern University Medical School, 303 E. Chicago Avenue, Chicago, IL-60611-3008, USA
| |
Collapse
|
44
|
Eriksson JE, He T, Trejo-Skalli AV, Härmälä-Braskén AS, Hellman J, Chou YH, Goldman RD. Specific in vivo phosphorylation sites determine the assembly dynamics of vimentin intermediate filaments. J Cell Sci 2004; 117:919-32. [PMID: 14762106 DOI: 10.1242/jcs.00906] [Citation(s) in RCA: 244] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Intermediate filaments (IFs) continuously exchange between a small, depolymerized fraction of IF protein and fully polymerized IFs. To elucidate the possible role of phosphorylation in regulating this equilibrium, we disrupted the exchange of phosphate groups by specific inhibition of dephosphorylation and by specific phosphorylation and site-directed mutagenesis of two of the major in vivo phosphorylation sites determined in this study. Inhibition of type-1 (PP1) and type-2A (PP2A) protein phosphatases in BHK-21 fibroblasts with calyculin-A, induced rapid vimentin phosphorylation in concert with disassembly of the IF polymers into soluble tetrameric vimentin oligomers. This oligomeric composition corresponded to the oligopeptides released by cAMP-dependent kinase (PKA) following in vitro phosphorylation. Characterization of the (32)P-labeled vimentin phosphopeptides, demonstrated Ser-4, Ser-6, Ser-7, Ser-8, Ser-9, Ser-38, Ser-41, Ser-71, Ser-72, Ser-418, Ser-429, Thr-456, and Ser-457 as significant in vivo phosphorylation sites. A number of the interphase-specific high turnover sites were shown to be in vitro phosphorylation sites for PKA and protein kinase C (PKC). The effect of presence or absence of phosphate groups on individual subunits was followed in vivo by microinjecting PKA-phosphorylated (primarily S38 and S72) and mutant vimentin (S38:A, S72:A), respectively. The PKA-phosphorylated vimentin showed a clearly decelerated filament formation in vivo, whereas obstruction of phosphorylation at these sites by site-directed mutagenesis had no significant effect on the incorporation rates of subunits into assembled polymers. Taken together, our results suggest that elevated phosphorylation regulates IF assembly in vivo by changing the equilibrium constant of subunit exchange towards a higher off-rate.
Collapse
Affiliation(s)
- John E Eriksson
- Department of Biology, Laboratory of Animal Physiology, University of Turku, Science Building 1, FIN-20014 Turku, Finland.
| | | | | | | | | | | | | |
Collapse
|
45
|
Abstract
The RAF-1 serine-threonine kinase plays a central role in signal transduction pathways involved in cell survival and proliferation. The concept of RAF-1-targeted disruption of cell signaling for therapeutic purposes was first advanced in 1989 with the demonstration of tumor growth inhibition in athymic mice and radiosensitization of human squamous carcinoma cells transfected with a vector expressing antisense cDNA. However, the clinical application of antisense strategies has awaited the development of improved antisense oligonucleotide technologies and drug delivery methods. Nuclease-resistant phosphorothioated antisense oligonucleotides have been the focus of pharmaceutical industry attention. In vivo delivery of nuclease-sensitive, natural backbone/phosphodiester oligonucleotides has remained a formidable challenge. Liposomal encapsulation of antisense oligonucleotides protects them from degradation and enhances drug delivery. Here, we review the importance of targeting RAF-1 signaling in cancer therapy and the preclinical and clinical experiences with a liposomal formulation of a nuclease-sensitive, ends-modified antisense RAF oligonucleotide.
Collapse
Affiliation(s)
- Usha Kasid
- Department of Radiation Medicine, Lombardi Cancer Center, Georgetown University Medical Center, Washington, DC 20007, USA
| | | |
Collapse
|
46
|
Blasi F, Ciarrocchi A, Luddi A, Strazza M, Riccio M, Santi S, Arcone R, Pietropaolo C, D'Angelo R, Costantino-Ceccarini E, Melli M. Stage-specific gene expression in early differentiating oligodendrocytes. Glia 2002; 39:114-23. [PMID: 12112363 DOI: 10.1002/glia.10092] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The screening of a differential library from precursor and differentiated oligodendrocytes, obtained through the representational difference analysis (RDA) technique, has generated a number of cDNA recombinants corresponding to mRNA coding for known and unknown proteins: (1) mRNA coding for proteins involved in protein synthesis, (2) mRNA coding for proteins involved in the organization of the cytoskeleton, and (3) mRNA coding for proteins of unknown function. The expression profile of the mRNA was studied by Northern blot hybridization to the poly-A(+) mRNA from primary rat progenitor and differentiated oligodendrocytes. In most cases, hybridization to the precursor was higher than hybridization to the differentiated mRNA, supporting the validity of the differential screening. Hybridization of the cDNA to rat cerebral hemisphere and brain stem poly-A(+) mRNA, isolated from 1- to 90-day-old rats, confirms the results obtained with the mRNA from differentiating oligodendrocytes. The intensity of the hybridization bands decreases as differentiation proceeds. The pattern of expression observed in oligodendrocytes is different from that found in the brain only in the case of the nexin-1 mRNA, the level of which remains essentially constant throughout differentiation both in the brain stem and in the cerebral hemispheres, in agreement with the published data. In contrast, the intensity of hybridization to the oligodendrocyte mRNA is dramatically lower in the differentiated cells compared with the progenitor oligodendrocyte cells. Some of the recombinant cDNA represent mRNA sequences present at high frequency distribution in the cells, while others belong to the rare sequences group. Six recombinants code for proteins of the ribosomal family, suggesting that of approximately 70 known ribosomal proteins, only a few are upregulated during oligodendrocyte differentiation. The third category of open reading frame (ORF) is represented by rare messengers coding for proteins of unknown functions and includes six clones: RDA 279, 11, 95, 96, 254, and 288.
Collapse
|
47
|
Hindley A, Kolch W. Extracellular signal regulated kinase (ERK)/mitogen activated protein kinase (MAPK)-independent functions of Raf kinases. J Cell Sci 2002; 115:1575-81. [PMID: 11950876 DOI: 10.1242/jcs.115.8.1575] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Raf comprises a family of three kinases, A-Raf, B-Raf and Raf-1, which are best known as key regulators of the MEK—MAPK/ERK cascade. This module is often perceived as a linear pathway in which ERK is the effector. However,recent advances have unveiled a role for Raf outside this established signalling unit. Current evidence, including gene-knockout studies in mice,suggests that there are ERK-independent functions of Raf kinases. Regulation of apoptosis is one area in which Raf may function independently of ERK,although its substrates remain to be identified. Other studies have suggested that Raf has kinase-independent functions and may act as a scaffold protein.
Collapse
Affiliation(s)
- Alison Hindley
- The Beatson Institute for Cancer Research, CRC Beatson Laboratories, Glasgow, G61 1BD, UK
| | | |
Collapse
|
48
|
Broustas CG, Grammatikakis N, Eto M, Dent P, Brautigan DL, Kasid U. Phosphorylation of the myosin-binding subunit of myosin phosphatase by Raf-1 and inhibition of phosphatase activity. J Biol Chem 2002; 277:3053-9. [PMID: 11719507 DOI: 10.1074/jbc.m106343200] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Raf-1 serine/threonine protein kinase plays an important role in cell survival, proliferation, and migration; however, the specific targets of Raf-1 in diverse cellular processes are not clearly defined. Myosin phosphatase activity is critical to the regulation of cytoskeletal reorganization, cytokinesis, and cell motility. Here, we describe the association of Raf-1 with myosin phosphatase and phosphorylation of the regulatory myosin-binding subunit (MBS) of myosin phosphatase by Raf-1. Treatment of cells with phorbol 12-myristate 13-acetate has been shown to stimulate Raf-1 protein kinase. To determine the effect of enzymatic activation of Raf-1 on MBS phosphorylation, COS-1 cells were transiently transfected with FLAG-tagged full-length Raf-1. A significantly higher phosphorylation of purified glutathione S-transferase-tagged truncated MBS protein (amino acids 654-880) occurred in the presence of FLAG-Raf-1 immunoprecipitated from phorbol 12-myristate 13-acetate-treated cells compared with untreated cells ( approximately 3.0-fold). Using a sequential kinase-phosphatase assay and phosphorylated myosin light chain as substrate in the phosphatase reaction, we showed that Raf-1-associated protein phosphatase-specific activity was inhibited (relative phosphatase activity without and with adenosine 5'-O-(3-thiotriphosphate): 100 and approximately 30%, respectively). Previously, ionizing radiation has been shown to activate Raf-1 (Kasid, U., Suy, S., Dent, P., Ray, S., Whiteside, T. L., and Sturgill, T. W. (1996) Nature 382, 813-816). Exposure of cells to ionizing radiation resulted in the increased association of Raf-1 with MBS (3-6-fold versus unirradiated control) and inhibition of Raf-1-associated protein phosphatase-specific activity (relative phosphatase activity without and with ionizing radiation: 100 and approximately 54%, respectively). Our studies identify MBS as a new substrate of Raf-1 and implicate a role for Raf-1 in the regulation of pathways involving myosin phosphatase activity.
Collapse
Affiliation(s)
- Constantinos G Broustas
- Department of Radiation Medicine, Lombardi Cancer Center, Georgetown University, Washington, DC 20007, USA
| | | | | | | | | | | |
Collapse
|
49
|
Meadows GG, Zhang H, Ge X. Specific amino acid deficiency alters the expression of genes in human melanoma and other tumor cell lines. J Nutr 2001; 131:3047S-50S. [PMID: 11694646 DOI: 10.1093/jn/131.11.3047s] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
This study determined the effect of tyrosine (Tyr) and phenylalanine (Phe) deprivation on protein expression and phosphorylation of mitogen-activated protein kinase kinase 4 (MKK4)/stress-activated protein/Erk kinase (SEK1), a metastasis suppressor gene. Differential display and suppressive subtractive hybridization techniques identified genes modulated by Tyr and Phe deprivation. Expression of MKK4/SEK1 protein varied widely among human A375, A375SM and SB2 melanoma, PC-3 and DU145 prostate cancer, and MDA-MB-231 breast cancer cell lines and within the different lines. Phosphorylation of the MKK4/SEK1 protein similarly varied. No differences in MKK4/SEK1 gene expression or in the 41 other metastasis and tumor suppressor genes were found in A375 melanoma cells cultured in Tyr- and Phe-deprived media. A number of up-regulated and down-regulated genes in A375 melanoma cells were identified by differential display and suppressive subtractive hybridization that were pertinent to regulation of cytoskeletal organization, cell movement, gene transcription and metastasis. Two tumor marker genes, the gene for enolase and FUS/CHOP, were down-regulated by Tyr and Phe deprivation. This study shows that tumor cells display heterogeneity in their response to deprivation of Tyr and Phe and that these amino acids may be signaling molecules that regulate gene expression and function in tumor cells.
Collapse
Affiliation(s)
- G G Meadows
- Cancer Prevention and Research Center, Department of Pharmaceutical Sciences, College of Pharmacy, Washington State University, Pullman, WA 99164-6510, USA.
| | | | | |
Collapse
|