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Li Z, Yan G, Yang M, Liu X, Lian Y, Sun M, Pan W. CBLC promotes the development of colorectal cancer by promoting ABI1 degradation to activate the ERK signaling pathway. Transl Oncol 2024; 45:101992. [PMID: 38743987 PMCID: PMC11109901 DOI: 10.1016/j.tranon.2024.101992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 04/11/2024] [Accepted: 05/07/2024] [Indexed: 05/16/2024] Open
Abstract
CBLC (CBL proto-oncogene C) is an E3 ubiquitin protein ligase that plays a key role in cancers. However, the function and mechanism of CBLC in colorectal cancer (CRC) has not been fully elucidated. The aim of this study was to investigate the function of CBLC in CRC and its underlying molecular mechanism. High CBLC levels were certified in tumor tissues of CRC patients, and its expression was positively associated with TNM stage. Next, we explored the role of CBLC in CRC using gain or loss of function. For biological function analysis, CCK-8 cell proliferation, colony formation, flow cytometry, scratch, and transwell assays collectively suggested that CBLC overexpression promoted cell proliferation, cell cycle progression, migration and invasion. As observed, CBLC knockdown exhibited exactly opposite effects, resulting in impaired tumorigenicity in vitro. Xenograft studies displayed that CBLC overexpression accelerated tumor growth and promoted tumor metastasis to the lung, while the inhibitory effects of CBLC knockdown on tumorigenicity and metastasis ability of CRC cells was also confirmed. Furthermore, the molecular mechanism of CBLC in CRC was explored. CBLC induced the activation of ERK signaling pathway, further leading to its pro-tumor role. Notably, CBLC decreased ABI1 (Abelson interactor protein-1, a candidate tumor suppressor) protein levels through its ubiquitin ligase activity, while ABI1 upregulation abolished the effects of CBLC on the tumorigenesis of CRC. Taken together, these results demonstrate that CBLC acts as a tumor promoter in CRC through triggering the ubiquitination and degradation of ABI1 and activating the ERK signaling pathway. CBLC may be a potential novel target for CRC.
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Affiliation(s)
- Zhan Li
- Department of General Surgery, Liaoyang City Central Hospital, Liaoyang, Liaoning Province, China
| | - Guanyu Yan
- Department of Gastroenterology, The First Hospital of China Medical University, Shenyang, Liaoning Province, China
| | - Meiqi Yang
- Department of Gastroenterology, The First Hospital of China Medical University, Shenyang, Liaoning Province, China
| | - Xingwu Liu
- Department of Gastroenterology, The First Hospital of China Medical University, Shenyang, Liaoning Province, China
| | - Yuan Lian
- General Hospital of Fuxin Mining Industry Group of Liaoning Health Industry Group, Fuxin, Liaoning Province, China
| | - Mingjun Sun
- Department of Gastroenterology, The First Hospital of China Medical University, Shenyang, Liaoning Province, China.
| | - Wenjun Pan
- Department of General Surgery, Liaoyang City Central Hospital, Liaoyang, Liaoning Province, China.
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2
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Liu L, Liu X, Chen Y, Kong M, Zhang J, Jiang M, Zhou H, Yang J, Chen X, Zhang Z, Wu C, Jiang X, Zhang J. Paxillin/HDAC6 regulates microtubule acetylation to promote directional migration of keratinocytes driven by electric fields. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2024; 1871:119628. [PMID: 37949303 DOI: 10.1016/j.bbamcr.2023.119628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 10/18/2023] [Accepted: 11/03/2023] [Indexed: 11/12/2023]
Abstract
Endogenous electric fields (EFs) have been demonstrated to facilitate wound healing by directing the migration of epidermal cells. Despite the identification of numerous molecules and signaling pathways that are crucial for the directional migration of keratinocytes under EFs, the underlying molecular mechanisms remain undefined. Previous studies have indicated that microtubule (MT) acetylation is linked to cell migration, while Paxillin exerts a significant influence on cell motility. Therefore, we postulated that Paxillin could enhance EF-induced directional migration of keratinocytes by modulating MT acetylation. In the present study, we observed that EFs (200 mV/mm) induced migration of human immortalized epidermal cells (HaCaT) towards the anode, while upregulating Paxillin, downregulating HDAC6, and increasing the level of microtubule acetylation. Our findings suggested that Paxillin plays a pivotal role in inhibiting HDAC6-mediated microtubule acetylation during directional migration under EF regulation. Conversely, downregulation of Paxillin decreased microtubule acetylation and electrotaxis of epidermal cells by promoting HDAC6 expression, and this effect could be reversed by the addition of tubacin, an HDAC6-specific inhibitor. Furthermore, we observed that EFs also mediated the polarization of Paxillin and acetylated α-tubulin, which is critical for directional migration. In conclusion, our study revealed that MT acetylation in EF-guided keratinocyte migration is regulated by the Paxillin/HDAC6 signaling pathway, providing a novel theoretical foundation for the molecular mechanism of EF-guided directional migration of keratinocytes.
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Affiliation(s)
- Luojia Liu
- Department of Plastic Surgery, State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, Third Military Medical University (Army Medical University), 400038 Chongqing, China
| | - Xiaoqiang Liu
- Department of Plastic Surgery, State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, Third Military Medical University (Army Medical University), 400038 Chongqing, China
| | - Ying Chen
- Department of Plastic Surgery, State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, Third Military Medical University (Army Medical University), 400038 Chongqing, China
| | - Meng Kong
- Department of Plastic Surgery, State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, Third Military Medical University (Army Medical University), 400038 Chongqing, China
| | - Jinghong Zhang
- Department of Plastic Surgery, State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, Third Military Medical University (Army Medical University), 400038 Chongqing, China
| | - Min Jiang
- Department of Plastic Surgery, State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, Third Military Medical University (Army Medical University), 400038 Chongqing, China
| | - Hongling Zhou
- Department of Plastic Surgery, State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, Third Military Medical University (Army Medical University), 400038 Chongqing, China
| | - Jinrui Yang
- Department of Plastic Surgery, State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, Third Military Medical University (Army Medical University), 400038 Chongqing, China
| | - Xu Chen
- Department of Plastic Surgery, State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, Third Military Medical University (Army Medical University), 400038 Chongqing, China
| | - Ze Zhang
- Department of Plastic Surgery, State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, Third Military Medical University (Army Medical University), 400038 Chongqing, China
| | - Chao Wu
- Department of Plastic Surgery, State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, Third Military Medical University (Army Medical University), 400038 Chongqing, China
| | - Xupin Jiang
- Department of Plastic Surgery, State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, Third Military Medical University (Army Medical University), 400038 Chongqing, China.
| | - Jiaping Zhang
- Department of Plastic Surgery, State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, Third Military Medical University (Army Medical University), 400038 Chongqing, China.
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3
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He Y, Shi Q, Ling Y, Guo H, Fei Y, Wu R, Tang C, Zhang X, Yao L. ABLIM1, a novel ubiquitin E3 ligase, promotes growth and metastasis of colorectal cancer through targeting IĸBα ubiquitination and activating NF-ĸB signaling. Cell Death Differ 2024; 31:203-216. [PMID: 38228802 PMCID: PMC10850134 DOI: 10.1038/s41418-024-01256-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 12/29/2023] [Accepted: 01/03/2024] [Indexed: 01/18/2024] Open
Abstract
Actin-binding LIM protein 1 (ABLIM1), a member of the LIM-domain protein family, has been reported as a suppressor in several tumors whereas its role in colorectal cancer (CRC) remains unknown. In this study, we find that ABLIM1 is up-regulated in CRC patients and high levels of ABLIM1 predict short disease-free survival time. Knock-down of ABLIM1 in CRC cell lines by lenti-virus leads to inhibited cell proliferation, migration, and invasion capabilities in vitro and impaired growth of tumor xenografts and liver metastasis lesions in vivo, while ABLIM1 overexpression accelerates tumor growth and invasion in vitro. Mechanistically, we uncover that ABLIM1 activates the NF-ĸB/CCL-20 signaling through modulating IĸBα ubiquitination and proteasomal-mediated degradation. Further co-immunoprecipitation, in vivo and in vitro ubiquitination assays reveal ABLIM1 as a novel ubiquitin E3 ligase binding to IĸBα. Interestingly, The E3 ligase catalysis activity of ABLIM1 depends on its 402-778aa rather than its LIM domains and its interaction with IĸBα relies on the HP domain. Our findings delineate the oncogenic role of ABLIM1 in CRC progression and reveal it as a novel E3 ligase targeting IĸBα, providing new insights into the regulation of NF-ĸB signaling in tumors.
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Affiliation(s)
- Ying He
- Central Laboratory, First Affiliated Hospital of Huzhou University, Huzhou, 313000, Zhejiang, China
- Huzhou Key Laboratory of Translational Medicine, First People's Hospital of Huzhou, Huzhou, 313000, Zhejiang, China
| | - Qian Shi
- Central Laboratory, First Affiliated Hospital of Huzhou University, Huzhou, 313000, Zhejiang, China
- Huzhou Key Laboratory of Translational Medicine, First People's Hospital of Huzhou, Huzhou, 313000, Zhejiang, China
| | - Yuhang Ling
- Central Laboratory, First Affiliated Hospital of Huzhou University, Huzhou, 313000, Zhejiang, China
- Huzhou Key Laboratory of Translational Medicine, First People's Hospital of Huzhou, Huzhou, 313000, Zhejiang, China
| | - Huihui Guo
- Central Laboratory, First Affiliated Hospital of Huzhou University, Huzhou, 313000, Zhejiang, China
- Huzhou Key Laboratory of Translational Medicine, First People's Hospital of Huzhou, Huzhou, 313000, Zhejiang, China
| | - Yi Fei
- Department of Colorectal Surgery, First Affiliated Hospital of Huzhou University, Huzhou, 313000, Zhejiang, China
| | - Ruoyu Wu
- Department of Gastroenterology, First Affiliated Hospital of Huzhou University, Huzhou, 313000, Zhejiang, China
| | - Chengwu Tang
- Central Laboratory, First Affiliated Hospital of Huzhou University, Huzhou, 313000, Zhejiang, China.
- Huzhou Key Laboratory of Translational Medicine, First People's Hospital of Huzhou, Huzhou, 313000, Zhejiang, China.
| | - Xilin Zhang
- Central Laboratory, First Affiliated Hospital of Huzhou University, Huzhou, 313000, Zhejiang, China.
- Huzhou Key Laboratory of Translational Medicine, First People's Hospital of Huzhou, Huzhou, 313000, Zhejiang, China.
| | - Linhua Yao
- Huzhou Key Laboratory of Translational Medicine, First People's Hospital of Huzhou, Huzhou, 313000, Zhejiang, China.
- Department of Gastroenterology, First Affiliated Hospital of Huzhou University, Huzhou, 313000, Zhejiang, China.
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4
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Small GW, Akhtari FS, Green AJ, Havener TM, Sikes M, Quintanhila J, Gonzalez RD, Reif DM, Motsinger-Reif AA, McLeod HL, Wiltshire T. Pharmacogenomic Analyses Implicate B Cell Developmental Status and MKL1 as Determinants of Sensitivity toward Anti-CD20 Monoclonal Antibody Therapy. Cells 2023; 12:1574. [PMID: 37371044 DOI: 10.3390/cells12121574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 06/02/2023] [Accepted: 06/04/2023] [Indexed: 06/29/2023] Open
Abstract
Monoclonal antibody (mAb) therapy directed against CD20 is an important tool in the treatment of B cell disorders. However, variable patient response and acquired resistance remain important clinical challenges. To identify genetic factors that may influence sensitivity to treatment, the cytotoxic activity of three CD20 mAbs: rituximab; ofatumumab; and obinutuzumab, were screened in high-throughput assays using 680 ethnically diverse lymphoblastoid cell lines (LCLs) followed by a pharmacogenomic assessment. GWAS analysis identified several novel gene candidates. The most significant SNP, rs58600101, in the gene MKL1 displayed ethnic stratification, with the variant being significantly more prevalent in the African cohort and resulting in reduced transcript levels as measured by qPCR. Functional validation of MKL1 by shRNA-mediated knockdown of MKL1 resulted in a more resistant phenotype. Gene expression analysis identified the developmentally associated TGFB1I1 as the most significant gene associated with sensitivity. qPCR among a panel of sensitive and resistant LCLs revealed immunoglobulin class-switching as well as differences in the expression of B cell activation markers. Flow cytometry showed heterogeneity within some cell lines relative to surface Ig isotype with a shift to more IgG+ cells among the resistant lines. Pretreatment with prednisolone could partly reverse the resistant phenotype. Results suggest that the efficacy of anti-CD20 mAb therapy may be influenced by B cell developmental status as well as polymorphism in the MKL1 gene. A clinical benefit may be achieved by pretreatment with corticosteroids such as prednisolone followed by mAb therapy.
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Affiliation(s)
- George W Small
- Pharmacotherapy and Experimental Therapeutics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Farida S Akhtari
- Biostatistics and Computational Biology Branch, Division of Intramural Research, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Adrian J Green
- Department of Biological Sciences, Bioinformatics Research Center, North Carolina State University, Raleigh, NC 27695, USA
| | - Tammy M Havener
- Structural Genomics Consortium and Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Michael Sikes
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695, USA
| | | | - Ricardo D Gonzalez
- Pharmacotherapy and Experimental Therapeutics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - David M Reif
- Predictive Toxicology Branch, Division of Translational Toxicology, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Alison A Motsinger-Reif
- Biostatistics and Computational Biology Branch, Division of Intramural Research, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Howard L McLeod
- Center for Precision Medicine and Functional Genomics, Utah Tech University, 225 South University Ave, St. George, UT 84770, USA
| | - Tim Wiltshire
- Pharmacotherapy and Experimental Therapeutics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Center for Pharmacogenomics and Individualized Therapy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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5
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Wisniewski DJ, Liyasova MS, Korrapati S, Zhang X, Ratnayake S, Chen Q, Gilbert SF, Catalano A, Voeller D, Meerzaman D, Guha U, Porat-Shliom N, Annunziata CM, Lipkowitz S. Flotillin-2 regulates epidermal growth factor receptor activation, degradation by Cbl-mediated ubiquitination, and cancer growth. J Biol Chem 2023; 299:102766. [PMID: 36470425 PMCID: PMC9823131 DOI: 10.1016/j.jbc.2022.102766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 11/21/2022] [Accepted: 11/22/2022] [Indexed: 12/08/2022] Open
Abstract
Epidermal growth factor receptor (EGFR) signaling is frequently dysregulated in various cancers. The ubiquitin ligase Casitas B-lineage lymphoma proto-oncogene (Cbl) regulates degradation of activated EGFR through ubiquitination and acts as an adaptor to recruit proteins required for trafficking. Here, we used stable isotope labeling with amino acids in cell culture mass spectrometry to compare Cbl complexes with or without epidermal growth factor (EGF) stimulation. We identified over a hundred novel Cbl interactors, and a secondary siRNA screen found that knockdown of Flotillin-2 (FLOT2) led to increased phosphorylation and degradation of EGFR upon EGF stimulation in HeLa cells. In PC9 and H441 cells, FLOT2 knockdown increased EGF-stimulated EGFR phosphorylation, ubiquitination, and downstream signaling, reversible by EGFR inhibitor erlotinib. CRISPR knockout (KO) of FLOT2 in HeLa cells confirmed EGFR downregulation, increased signaling, and increased dimerization and endosomal trafficking. Furthermore, we determined that FLOT2 interacted with both Cbl and EGFR. EGFR downregulation upon FLOT2 loss was Cbl dependent, as coknockdown of Cbl and Cbl-b restored EGFR levels. In addition, FLOT2 overexpression decreased EGFR signaling and growth. Overexpression of wildtype (WT) FLOT2, but not the soluble G2A FLOT2 mutant, inhibited EGFR phosphorylation upon EGF stimulation in HEK293T cells. FLOT2 loss induced EGFR-dependent proliferation and anchorage-independent growth. Lastly, FLOT2 KO increased tumor formation and tumor volume in nude mice and NSG mice, respectively. Together, these data demonstrated that FLOT2 negatively regulated EGFR activation and dimerization, as well as its subsequent ubiquitination, endosomal trafficking, and degradation, leading to reduced proliferation in vitro and in vivo.
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Affiliation(s)
- David J Wisniewski
- Women's Malignancies Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA
| | - Mariya S Liyasova
- Women's Malignancies Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA
| | - Soumya Korrapati
- Women's Malignancies Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA
| | - Xu Zhang
- Thoracic and GI Malignancies Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA
| | - Shashikala Ratnayake
- Center for Biomedical Informatics and Information Technology, National Cancer Institute, Rockville, Maryland, USA
| | - Qingrong Chen
- Center for Biomedical Informatics and Information Technology, National Cancer Institute, Rockville, Maryland, USA
| | - Samuel F Gilbert
- Women's Malignancies Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA
| | - Alexis Catalano
- Women's Malignancies Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA
| | - Donna Voeller
- Women's Malignancies Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA
| | - Daoud Meerzaman
- Center for Biomedical Informatics and Information Technology, National Cancer Institute, Rockville, Maryland, USA
| | - Udayan Guha
- Thoracic and GI Malignancies Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA
| | - Natalie Porat-Shliom
- Thoracic and GI Malignancies Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA
| | - Christina M Annunziata
- Women's Malignancies Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA
| | - Stanley Lipkowitz
- Women's Malignancies Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA.
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Wybenga-Groot LE, Tench AJ, Simpson CD, Germain JS, Raught B, Moran MF, McGlade CJ. SLAP2 Adaptor Binding Disrupts c-CBL Autoinhibition to Activate Ubiquitin Ligase Function. J Mol Biol 2021; 433:166880. [PMID: 33617900 DOI: 10.1016/j.jmb.2021.166880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 02/05/2021] [Accepted: 02/12/2021] [Indexed: 10/22/2022]
Abstract
CBL is a RING type E3 ubiquitin ligase that functions as a negative regulator of tyrosine kinase signaling and loss of CBL E3 function is implicated in several forms of leukemia. The Src-like adaptor proteins (SLAP/SLAP2) bind to CBL and are required for CBL-dependent downregulation of antigen receptor, cytokine receptor, and receptor tyrosine kinase signaling. Despite the established role of SLAP/SLAP2 in regulating CBL activity, the nature of the interaction and the mechanisms involved are not known. To understand the molecular basis of the interaction between SLAP/SLAP2 and CBL, we solved the crystal structure of CBL tyrosine kinase binding domain (TKBD) in complex with SLAP2. The carboxy-terminal region of SLAP2 adopts an α-helical structure which binds in a cleft between the 4H, EF-hand, and SH2 domains of the TKBD. This SLAP2 binding site is remote from the canonical TKBD phospho-tyrosine peptide binding site but overlaps with a region important for stabilizing CBL in its autoinhibited conformation. In addition, binding of SLAP2 to CBL in vitro activates the ubiquitin ligase function of autoinhibited CBL. Disruption of the CBL/SLAP2 interface through mutagenesis demonstrated a role for this protein-protein interaction in regulation of CBL E3 ligase activity in cells. Our results reveal that SLAP2 binding to a regulatory cleft of the TKBD provides an alternative mechanism for activation of CBL ubiquitin ligase function.
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Affiliation(s)
- Leanne E Wybenga-Groot
- The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada; Program in Cell Biology, The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada; SPARC BioCentre, The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada.
| | - Andrea J Tench
- The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada; Program in Cell Biology, The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada; Department of Medical Biophysics, University of Toronto, 610 University Avenue, Toronto, ON M5G 2M9, Canada
| | - Craig D Simpson
- The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada; Program in Cell Biology, The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada
| | - Jonathan St Germain
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 1L7, Canada
| | - Brian Raught
- Department of Medical Biophysics, University of Toronto, 610 University Avenue, Toronto, ON M5G 2M9, Canada; Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 1L7, Canada
| | - Michael F Moran
- Program in Cell Biology, The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada; SPARC BioCentre, The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada; Department of Molecular Genetics, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
| | - C Jane McGlade
- The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada; Program in Cell Biology, The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada; Department of Medical Biophysics, University of Toronto, 610 University Avenue, Toronto, ON M5G 2M9, Canada.
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7
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Zhou X, Zheng L, Guan L, Ye J, Virag A, Harris SD, Lu L. The Scaffold Proteins Paxillin B and α-Actinin Regulate Septation in Aspergillus nidulans via Control of Actin Ring Contraction. Genetics 2020; 215:449-461. [PMID: 32317285 PMCID: PMC7268981 DOI: 10.1534/genetics.120.303234] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 04/12/2020] [Indexed: 11/29/2022] Open
Abstract
Cytokinesis, as the final step of cell division, plays an important role in fungal growth and proliferation. In the filamentous fungus Aspergillus nidulans, defective cytokinesis is able to induce abnormal multinuclear or nonnucleated cells and then result in reduced hyphal growth and abolished sporulation. Previous studies have reported that a conserved contractile actin ring (CAR) protein complex and the septation initiation network (SIN) signaling kinase cascade are required for cytokinesis and septation; however, little is known about the role(s) of scaffold proteins involved in these two important cellular processes. In this study, we show that a septum-localized scaffold protein paxillin B (PaxB) is essential for cytokinesis/septation in A. nidulans The septation defects observed in a paxB deletion strain resemble those caused by the absence of another identified scaffold protein, α-actinin (AcnA). Deletion of α-actinin (AcnA) leads to undetectable PaxB at the septation site, whereas deletion of paxB does not affect the localization of α-actinin at septa. However, deletion of either α-actinin (acnA) or paxB causes the actin ring to disappear at septation sites during cytokinesis. Notably, overexpression of α-actinin acnA partially rescues the septum defects of the paxB mutant but not vice versa, suggesting AcnA may play a dominant role over that of PaxB for cytokinesis and septation. In addition, PaxB and α-actinin affect the septal dynamic localization of MobA, a conserved component of the SIN pathway, suggesting they may affect the SIN protein complex function at septa. Protein pull-down assays combined with liquid chromatography-mass spectrometry identification indicate that α-actinin AcnA and PaxB likely do not directly interact, but presumably belong to an actin cytoskeleton protein network that is required for the assembly and contraction of the CAR. Taken together, findings in this study provide novel insights into the roles of conserved scaffold proteins during fungal septation in A. nidulans.
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Affiliation(s)
- Xiaogang Zhou
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, 210023, China
| | - Likun Zheng
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, 210023, China
| | - Luyu Guan
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, 210023, China
| | - Jing Ye
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, 210023, China
| | | | - Steven D Harris
- Department of Biological Sciences, University of Manitoba, Winnipeg, Canada
| | - Ling Lu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, 210023, China
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8
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Berhe K, Gebrearegay F, Gebremariam H. Prevalence and associated factors of zinc deficiency among pregnant women and children in Ethiopia: a systematic review and meta-analysis. BMC Public Health 2019; 19:1663. [PMID: 31829213 PMCID: PMC6907210 DOI: 10.1186/s12889-019-7979-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 11/20/2019] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Pregnant women and children are the most vulnerable groups to zinc deficiency. Despite the presence of few primary studies, studies that could provide strong evidence that would help policymakers to develop appropriate interventional strategies in addressing zinc deficiency among pregnant women and children are limited in Ethiopia. Therefore, the aim of this systematic review and meta-analysis was to estimate the national pooled prevalence and associated factors of zinc deficiency among pregnant women and children. METHODS We searched Pub Med, Scopus, CINAHL, Google Scholar, and Google for studies reported on zinc deficiency and associated factors among pregnant women and children. Search terms were 'zinc deficiency', 'zinc status', 'associated factors', 'children', 'pregnant women', and 'Ethiopia' using the boolean operators 'OR' or 'AND'. Searches were using English language. A preferred reporting item for systematic reviews and meta-analysis (PRISMA) checklist was used. Two authors independently reviewed the studies. The effect sizes of the meta-analysis were the prevalence of zinc deficiency and adjusted odds ratio (AOR) of the associated factors. Finally, the Comprehensive Meta-Analysis (CMA) version 3.3.07 was used for statistical analysis by applying the random-effects model and publication bias was assessed using funnel plots and Egger's test. RESULTS Thirteen studies (7 among pregnant women having total participants of 2371 pregnant women and 6 among children with total participants of 5154 children) were included in this systematic review and meta-analysis. Using the random-effects model, the pooled prevalence of zinc deficiency was 59.9% (95%CI: 51.9, 67.7%) and 38.4% (95%CI: 28.6, 49.4) among pregnant women and children, respectively. The associated factors for zinc deficiency among pregnant women were coffee intake (adjusted odds ratio (AOR) =1.76), low intake of animal source foods (AOR = 2.57), and inadequate diet diversity (AOR = 2.12). CONCLUSION Overall, zinc deficiency among pregnant women and children is a significant public health concern in Ethiopia. Promoting dietary modification to enhance the bioavailability of zinc, improving diet diversity, and consuming animal source foods would help in alleviating and/or minimizing the problem among the target groups. Zinc supplementation could also be considered for pregnant women and children.
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Affiliation(s)
- Kidanemaryam Berhe
- Department of Nutrition and Dietetics, School of Public Health, College of Health Sciences, Mekelle University, Mekelle, Tigray Ethiopia
| | - Freweini Gebrearegay
- Department of Nutrition and Dietetics, School of Public Health, College of Health Sciences, Mekelle University, Mekelle, Tigray Ethiopia
| | - Hadush Gebremariam
- Department of Nutrition and Dietetics, School of Public Health, College of Health Sciences, Mekelle University, Mekelle, Tigray Ethiopia
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9
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Abstract
Receptor Tyrosine Kinase (RTK) signaling is essential for normal biological processes and disruption of this regulation can lead to tumor initiation and progression. Cbl proteins (Cbl, Cbl-b and Cbl-c) are a family of RING finger (RF) ubiquitin ligases that negatively regulate a variety of RTKs, including EGFR, MET, and RET. Recent studies have identified Cbl mutations associated with human myeloid neoplasias in approximately 5% of the cases. Cbl-c is the most recently identified human Cbl protein and is expressed exclusively in epithelial cells. We identified a novel cDNA that was isolated from a mouse mammary cancer from the C3(1) Large T Antigen transgenic model. This mutant cDNA encodes a protein that has a deletion in the RF domain of Cbl-c, thereby resembling known Cbl family mutations associated with myeoloid neoplasias. Genomic analysis of both parental and transgenic lines shows no evidence of germline mutation indicating that this mutation is likely a somatic mutation. The mutant protein enhances transformation of NIH 3T3 cells when expressed in combination with SV40 Large T antigen. Together these data are consistent with a second hit mutation. In overexpression studies, this mutant Cbl-c protein fails to mediate ubiquitination of activated EGFR and acts in a dominant negative fashion to prevent ubiquitination and downregulation of the activated EGFR by wild type Cbl proteins. Mechanistically, the mutant Cbl-c binds to the EGFR and prevents recruitment of the wild type Cbl protein. Furthermore, data mining reveals Cbl-c mutations associated with solid tumors in humans. Subsequent cell-based analysis demonstrates a similar loss of E3 function and dominant negative effects for one of these human mutations. These data suggest that like Cbl mutations in myeloid neoplasms, loss of Cbl-c function may contribute to the pathogenesis of solid tumors in murine models and in humans.
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TRIP6 antagonizes the recruitment of A20 and CYLD to TRAF6 to promote the LPA2 receptor-mediated TRAF6 activation. Cell Discov 2016; 2. [PMID: 27134758 PMCID: PMC4850058 DOI: 10.1038/celldisc.2015.48] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The elevated lysophosphatidic acid signaling has been causally linked to cancer-associated inflammation and tumorigenesis through upregulation of nuclear factor-κB signaling. However, how this signaling event is regulated has not yet been fully understood. Here we demonstrate that TRIP6, an LPA2 receptor-interacting adaptor protein, functions as a positive regulator of nuclear factor-κB and JNK signaling through direct binding to and activation of the E3 ligase TRAF6. Upon lysophosphatidic acid stimulation, TRIP6 recruits TRAF6 to the LPA2 receptor and promotes lysophosphatidic acid-induced JNK and nuclear factor-κB activation in a TRAF6-dependent manner. TRIP6 antagonizes the recruitment of deubiquitinases A20 and CYLD to TRAF6, thus sustaining the E3 ligase activity of TRAF6 and augmenting lysophosphatidic acid-activated nuclear factor-κB signaling. In contrast, depletion of TRIP6 by TRIP6-specific shRNA or Cas9/sgRNA greatly enhances the association of TRAF6 with A20 and CYLD, and attenuates lysophosphatidic acid-induced muclear factor-κB and JNK/p38 activation in ovarian cancer cells. On the other hand, TRAF6 also regulates TRIP6 by facilitating its binding to nuclear factor-κB p65 and phosphorylation by c-Src. Together, TRIP6 cooperates with TRAF6 to regulate the LPA2 receptor signaling, which may ultimately contribute to chronic inflammation, apoptotic resistance and cell invasion.
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11
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Frankum J, Moudry P, Brough R, Hodny Z, Ashworth A, Bartek J, Lord CJ. Complementary genetic screens identify the E3 ubiquitin ligase CBLC, as a modifier of PARP inhibitor sensitivity. Oncotarget 2015; 6:10746-58. [PMID: 25883215 PMCID: PMC4484416 DOI: 10.18632/oncotarget.3628] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 02/20/2015] [Indexed: 01/06/2023] Open
Abstract
Based on a series of basic, preclinical and clinical studies, the Poly (ADP-ribose) Polymerase 1 (PARP1) inhibitor, olaparib, has recently been approved for use in ovarian cancer patients with BRCA1 or BRCA2 mutations. By identifying novel predictive biomarkers of tumour cell sensitivity to olaparib, it is possible that the utility of PARP inhibitors could be extended beyond this patient subgroup. Many of the known genetic determinants of PARP inhibitor response have key roles in DNA damage response (DDR) pathways. Although protein ubiquitylation is known to play an important role in regulating the DDR, the exact mechanisms by which this occurs are not fully understood. Using two parallel RNA interference-based screening approaches, we identified the E3 ubiquitin ligase, CBLC, as a candidate biomarker of response to olaparib. We validated this observation by demonstrating that silencing of CBLC causes increased sensitivity to olaparib in breast cancer cell line models and that defective homologous recombination (HR) DNA repair is the likely cause. This data provides an example of how defects in the ubiquitin machinery have the potential to influence the response of tumour cells to PARP inhibitors.
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Affiliation(s)
- Jessica Frankum
- The CRUK Gene Function Laboratory and Breakthrough Breast Cancer Research Centre, The Institute of Cancer Research, London, UK
| | - Pavel Moudry
- Danish Cancer Society Research Center, Strandboulevarden, Copenhagen, Denmark
| | - Rachel Brough
- The CRUK Gene Function Laboratory and Breakthrough Breast Cancer Research Centre, The Institute of Cancer Research, London, UK
| | - Zdenek Hodny
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Videnska, Czech Republic
| | - Alan Ashworth
- The CRUK Gene Function Laboratory and Breakthrough Breast Cancer Research Centre, The Institute of Cancer Research, London, UK
| | - Jiri Bartek
- Danish Cancer Society Research Center, Strandboulevarden, Copenhagen, Denmark
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Videnska, Czech Republic
| | - Christopher J. Lord
- The CRUK Gene Function Laboratory and Breakthrough Breast Cancer Research Centre, The Institute of Cancer Research, London, UK
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12
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Ohanian J, Pieri M, Ohanian V. Non-receptor tyrosine kinases and the actin cytoskeleton in contractile vascular smooth muscle. J Physiol 2014; 593:3807-14. [PMID: 25433074 DOI: 10.1113/jphysiol.2014.284174] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 11/14/2014] [Indexed: 01/01/2023] Open
Abstract
The contractility of vascular smooth muscle cells within the walls of arteries is regulated by mechanical stresses and vasoactive signals. Transduction of these diverse stimuli into a cellular response occurs through many different mechanisms, one being reorganisation of the actin cytoskeleton. In addition to a structural role in maintaining cellular architecture it is now clear that the actin cytoskeleton of contractile vascular smooth muscle cells is a dynamic structure reacting to changes in the cellular environment. Equally clear is that disrupting the cytoskeleton or interfering with its rearrangement, has profound effects on artery contractility. The actin cytoskeleton associates with dense plaques, also called focal adhesions, at the plasma membrane of smooth muscle cells. Vasoconstrictors and mechanical stress induce remodelling of the focal adhesions, concomitant with cytoskeletal reorganisation. Recent work has shown that non-receptor tyrosine kinases and tyrosine phosphorylation of focal adhesion proteins such as paxillin and Hic-5 are important for actin cytoskeleton and focal adhesion remodelling and contraction.
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Affiliation(s)
- Jacqueline Ohanian
- Institute of Cardiovascular Sciences, Manchester Academic Health Services Centre, University of Manchester, Manchester, UK
| | - Maria Pieri
- Institute of Cardiovascular Sciences, Manchester Academic Health Services Centre, University of Manchester, Manchester, UK
| | - Vasken Ohanian
- Institute of Cardiovascular Sciences, Manchester Academic Health Services Centre, University of Manchester, Manchester, UK
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13
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Desai LP, Zhou Y, Estrada AV, Ding Q, Cheng G, Collawn JF, Thannickal VJ. Negative regulation of NADPH oxidase 4 by hydrogen peroxide-inducible clone 5 (Hic-5) protein. J Biol Chem 2014; 289:18270-8. [PMID: 24831009 DOI: 10.1074/jbc.m114.562249] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Hydrogen peroxide-inducible clone 5 (Hic-5) is a focal adhesion adaptor protein induced by the profibrotic cytokine TGF-β1. We have demonstrated previously that TGF-β1 induces myofibroblast differentiation and lung fibrosis by activation of the reactive oxygen species-generating enzyme NADPH oxidase 4 (Nox4). Here we investigated a potential role for Hic-5 in regulating Nox4, myofibroblast differentiation, and senescence. In normal human diploid fibroblasts, TGF-β1 induces Hic-5 expression in a delayed manner relative to the induction of Nox4 and myofibroblast differentiation. Hic-5 silencing induced constitutive Nox4 expression and enhanced TGF-β1-inducible Nox4 levels. The induction of constitutive Nox4 protein in Hic-5-silenced cells was independent of transcription and translation and controlled by the ubiquitin-proteasomal system. Hic-5 associates with the ubiquitin ligase Cbl-c and the ubiquitin-binding protein heat shock protein 27 (HSP27). The interaction of these proteins is required for the ubiquitination of Nox4 and for maintaining low basal levels of this reactive oxygen species-generating enzyme. Our model suggests that TGF-β1-induced Hic-5 functions as a negative feedback mechanism to limit myofibroblast differentiation and senescence by promoting the ubiquitin-proteasomal system-mediated degradation of Nox4. Together, these studies indicate that endogenous Hic-5 suppresses senescence and profibrotic activities of myofibroblasts by down-regulating Nox4 protein expression. Additionally, these are the first studies, to our knowledge, to demonstrate posttranslational regulation of Nox4.
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Affiliation(s)
- Leena P Desai
- From the Divisions of Pulmonary, Allergy, and Critical Care Medicine and
| | - Yong Zhou
- From the Divisions of Pulmonary, Allergy, and Critical Care Medicine and
| | - Aida V Estrada
- From the Divisions of Pulmonary, Allergy, and Critical Care Medicine and
| | - Qiang Ding
- From the Divisions of Pulmonary, Allergy, and Critical Care Medicine and
| | - Guangjie Cheng
- From the Divisions of Pulmonary, Allergy, and Critical Care Medicine and
| | - James F Collawn
- Cell, Developmental and Integrative Biology, University of Alabama, Birmingham, Birmingham, Alabama 35294
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14
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Xu X, Paik I, Zhu L, Bu Q, Huang X, Deng XW, Huq E. PHYTOCHROME INTERACTING FACTOR1 Enhances the E3 Ligase Activity of CONSTITUTIVE PHOTOMORPHOGENIC1 to Synergistically Repress Photomorphogenesis in Arabidopsis. THE PLANT CELL 2014; 26:1992-2006. [PMID: 24858936 PMCID: PMC4079364 DOI: 10.1105/tpc.114.125591] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2014] [Revised: 04/11/2014] [Accepted: 04/22/2014] [Indexed: 05/20/2023]
Abstract
CONSTITUTIVE PHOTOMORPHOGENIC1 (COP1) is a RING/WD40 repeat-containing ubiquitin E3 ligase that is conserved from plants to humans. COP1 forms complexes with SUPPRESSOR OF PHYTOCHROME A (SPA) proteins, and these complexes degrade positively acting transcription factors in the dark to repress photomorphogenesis. Phytochrome-interacting basic helix-loop-helix transcription factors (PIFs) also repress photomorphogenesis in the dark. In response to light, the phytochrome family of sensory photoreceptors simultaneously inactivates COP1-SPA complexes and induces the rapid degradation of PIFs to promote photomorphogenesis. However, the functional relationship between PIFs and COP1-SPA complexes is still unknown. Here, we present genetic evidence that the pif and cop1/spa Arabidopsis thaliana mutants synergistically promote photomorphogenesis in the dark. LONG HYPOCOTYL5 (HY5) is stabilized in the cop1 pif1, spa123 pif1, and pif double, triple, and quadruple mutants in the dark. Moreover, the hy5 mutant suppresses the constitutive photomorphogenic phenotypes of the pifq mutant in the dark. PIF1 forms complexes with COP1, HY5, and SPA1 and enhances the substrate recruitment and autoubiquitylation and transubiquitylation activities of COP1. These data uncover a novel function of PIFs as the potential cofactors of COP1 and provide a genetic and biochemical model of how PIFs and COP1-SPA complexes synergistically repress photomorphogenesis in the dark.
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Affiliation(s)
- Xiaosa Xu
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas 78712
| | - Inyup Paik
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas 78712
| | - Ling Zhu
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas 78712
| | - Qingyun Bu
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas 78712
| | - Xi Huang
- Peking-Yale Joint Center for Plant Molecular Genetics and Agro-Biotechnology, State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, College of Life Sciences, Peking University, Beijing 100871, China Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520
| | - Xing Wang Deng
- Peking-Yale Joint Center for Plant Molecular Genetics and Agro-Biotechnology, State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, College of Life Sciences, Peking University, Beijing 100871, China Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520
| | - Enamul Huq
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas 78712
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15
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Kales SC, Nau MM, Merchant AS, Lipkowitz S. Enigma prevents Cbl-c-mediated ubiquitination and degradation of RETMEN2A. PLoS One 2014; 9:e87116. [PMID: 24466333 PMCID: PMC3900716 DOI: 10.1371/journal.pone.0087116] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 12/23/2013] [Indexed: 12/24/2022] Open
Abstract
The Cbl proteins (Cbl, Cbl-b, and Cbl-c) are a highly conserved family of RING finger ubiquitin ligases (E3s) that function as negative regulators of tyrosine kinases in a wide variety of signal transduction pathways. In this study, we identify a new Cbl-c interacting protein, Enigma (PDLIM7). This interaction is specific to Cbl-c as Enigma fails to bind either of its closely related homologues, Cbl and Cbl-b. The binding between Enigma and Cbl-c is mediated through the LIM domains of Enigma as removal of all three LIM domains abrogates this interaction, while only LIM1 is sufficient for binding. Here we show that Cbl-c binds wild-type and MEN2A isoforms of the receptor tyrosine kinase, RET, and that Cbl-c enhances ubiquitination and degradation of activated RET. Enigma blocks Cbl-c-mediated RETMEN2A ubiquitination and degradation. Cbl-c decreased downstream ERK activation by RETMEN2A and co-expression of Enigma blocked the Cbl-c-mediated decrease in ERK activation. Enigma showed no detectable effect on Cbl-c-mediated ubiquitination of activated EGFR suggesting that this effect is specific to RET. Through mapping studies, we show that Cbl-c and Enigma bind RETMEN2A at different residues. However, binding of Enigma to RETMENA prevents Cbl-c recruitment to RETMEN2A. Consistent with these biochemical data, exploratory analyses of breast cancer patients with high expression of RET suggest that high expression of Cbl-c correlates with a good outcome, and high expression of Enigma correlates with a poor outcome. Together, these data demonstrate that Cbl-c can ubiquitinate and downregulate RETMEN2A and implicate Enigma as a positive regulator of RETMEN2A through blocking of Cbl-mediated ubiquitination and degradation.
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Affiliation(s)
- Stephen C. Kales
- Women’s Malignancies Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Marion M. Nau
- Women’s Malignancies Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Anand S. Merchant
- Center for Cancer Research Bioinformatics Core, Advanced Biomedical Computing Center, SAIC-Frederick, Frederick, Maryland, United States of America
| | - Stanley Lipkowitz
- Women’s Malignancies Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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16
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Iida K, Takeda-Kawaguchi T, Hada M, Yuriguchi M, Aoki H, Tamaoki N, Hatakeyama D, Kunisada T, Shibata T, Tezuka K. Hypoxia-enhanced derivation of iPSCs from human dental pulp cells. J Dent Res 2013; 92:905-10. [PMID: 23962749 DOI: 10.1177/0022034513502204] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Hypoxia enhances the reprogramming efficiency of human dermal fibroblasts to become induced pluripotent stem cells (iPSCs). Because we showed previously that hypoxia facilitates the isolation and maintenance of human dental pulp cells (DPCs), we examined here whether it promotes the reprogramming of DPCs to become iPSCs. Unlike dermal fibroblasts, early and transient hypoxia (3% O2) induced the transition of DPCs to iPSCs by 3.3- to 5.1-fold compared with normoxia (21% O2). The resulting iPSCs closely resembled embryonic stem cells as well as iPSCs generated in normoxia, as judged by morphology and expression of stem cell markers. However, sustained hypoxia strongly inhibited the appearance of iPSC colonies and altered their morphology, and anti-oxidants failed to suppress this effect. Transient hypoxia increased the expression levels of NANOG and CDH1 and modulated the expression of numerous genes, including those encoding chemokines and their receptors. Therefore, we conclude that hypoxia, when optimized for cell type, is a simple and useful tool to enhance the reprogramming of somatic cells to become iPSCs.
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Affiliation(s)
- K Iida
- Department of Oral and Maxillofacial Science, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu City, Gifu 501-1194, Japan
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