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Chai R, Zhao Y, Su Z, Liang W. Integrative analysis reveals a four-gene signature for predicting survival and immunotherapy response in colon cancer patients using bulk and single-cell RNA-seq data. Front Oncol 2023; 13:1277084. [PMID: 38023180 PMCID: PMC10644708 DOI: 10.3389/fonc.2023.1277084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 09/25/2023] [Indexed: 12/01/2023] Open
Abstract
Background Colon cancer (CC) ranks as one of the leading causes of cancer-related mortality globally. Single-cell transcriptome sequencing (scRNA-seq) offers precise gene expression data for distinct cell types. This study aimed to utilize scRNA-seq and bulk transcriptome sequencing (bulk RNA-seq) data from CC samples to develop a novel prognostic model. Methods scRNA-seq data was downloaded from the GSE161277 database. R packages including "Seurat", "Harmony", and "singleR" were employed to categorize eight major cell types within normal and tumor tissues. By comparing tumor and normal samples, differentially expressed genes (DEGs) across these major cell types were identified. Gene Ontology (GO) enrichment analyses of DEGs for each cell type were conducted using "Metascape". DEGs-based signature construction involved Cox regression and least absolute shrinkage operator (LASSO) analyses, performed on The Cancer Genome Atlas (TCGA) training cohort. Validation occurred in the GSE39582 and GSE33382 datasets. The expression pattern of prognostic genes was verified using spatial transcriptome sequencing (ST-seq) data. Ultimately, an established prognostic nomogram based on the gene signature and age was established and calibrated. Sensitivity to chemotherapeutic drugs was predicted with the "oncoPredict" R package. Results Using scRNA-Seq data, we examined 33,213 cells, categorizing them into eight cell types within normal and tumor samples. GO enrichment analysis revealed various cancer-related pathways across DEGs in these cell types. Among the 55 DEGs identified via univariate Cox regression, four independent prognostic genes emerged: PTPN6, CXCL13, SPINK4, and NPDC1. Expression validation through ST-seq confirmed PTPN6 and CXCL13 predominance in immune cells, while SPINK4 and NPDC1 were relatively epithelial cell-specific. Creating a four-gene prognostic signature, Kaplan-Meier survival analyses emphasized higher risk scores correlating with unfavorable prognoses, confirmed across training and validation cohorts. The risk score emerged as an independent prognostic factor, supported by a reliable nomogram. Intriguingly, drug sensitivity analysis unveiled contrasting anti-cancer drug responses in the two risk groups, suggesting significant clinical implications. Conclusion We developed a novel prognostic four-gene risk model, and these genes may act as potential therapeutic targets for CC.
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Affiliation(s)
- Ruoyang Chai
- Department of General Practice, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Yajie Zhao
- Department of Geriatrics, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Zhengjia Su
- Department of Geriatrics, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Wei Liang
- Department of Geriatrics, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
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2
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Gao H, Ni N, Zhang D, Wang Y, Tang Z, Sun N, Ju Y, Dai X, Zhang Y, Liu Y, Gu P. miR-762 regulates the proliferation and differentiation of retinal progenitor cells by targeting NPDC1. Cell Cycle 2020; 19:1754-1767. [PMID: 32544377 DOI: 10.1080/15384101.2020.1777805] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Retinal degenerations, which lead to irreversible decline in visual function, are still no effective recovery treatments. Currently, retinal progenitor cell (RPC) transplantation therapy is expected to provide a new approach to treat these diseases; however, the limited proliferation capacity and differentiation potential toward specific retinal neurons of RPCs hinder their potential clinical applications. microRNAs have been reported to serve as important regulators in the cell fate determination of stem/progenitor cells. In this study, our data demonstrated that miR-762 inhibited NPDC1 expression to positively regulate RPC proliferation and suppress RPC neuronal differentiation. Furthermore, the knockdown of miR-762 upregulated NPDC1 expression in RPCs, leading to the inhibition of RPC proliferation and the increase in neuronal differentiation. Moreover, NPDC1 could rescue anti-miR-762-induced RPC proliferation deficiency and the inhibitory effect of miR-762 on RPC differentiation. In conclusion, our study demonstrated that miR-762 plays a crucial role in regulating RPC proliferation and differentiation by directly targeting NPDC1, which is firstly reported that microRNAs positively regulate RPC proliferation and negatively regulate RPC differentiation, which provides a comprehensive understanding of the molecular mechanisms that dominate RPC proliferation and differentiation in vitro.
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Affiliation(s)
- Huiqin Gao
- Department of Ophthalmology, Ninth People's Hospital, Shanghai JiaoTong University School of Medicine , Shanghai, P.R. China.,Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology , Shanghai, P.R. China
| | - Ni Ni
- Department of Ophthalmology, Ninth People's Hospital, Shanghai JiaoTong University School of Medicine , Shanghai, P.R. China.,Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology , Shanghai, P.R. China
| | - Dandan Zhang
- Department of Ophthalmology, Ninth People's Hospital, Shanghai JiaoTong University School of Medicine , Shanghai, P.R. China.,Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology , Shanghai, P.R. China
| | - Yuyao Wang
- Department of Ophthalmology, Ninth People's Hospital, Shanghai JiaoTong University School of Medicine , Shanghai, P.R. China.,Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology , Shanghai, P.R. China
| | - Zhimin Tang
- Department of Ophthalmology, Ninth People's Hospital, Shanghai JiaoTong University School of Medicine , Shanghai, P.R. China.,Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology , Shanghai, P.R. China
| | - Na Sun
- Department of Ophthalmology, Ninth People's Hospital, Shanghai JiaoTong University School of Medicine , Shanghai, P.R. China.,Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology , Shanghai, P.R. China
| | - Yahan Ju
- Department of Ophthalmology, Ninth People's Hospital, Shanghai JiaoTong University School of Medicine , Shanghai, P.R. China.,Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology , Shanghai, P.R. China
| | - Xiaochan Dai
- Department of Ophthalmology, Ninth People's Hospital, Shanghai JiaoTong University School of Medicine , Shanghai, P.R. China.,Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology , Shanghai, P.R. China
| | - Yidan Zhang
- Department of Ophthalmology, Shanghai Children's Hospital, Shanghai Jiao Tong University , Shanghai, P.R. China
| | - Yan Liu
- Department of Ophthalmology, Ninth People's Hospital, Shanghai JiaoTong University School of Medicine , Shanghai, P.R. China.,Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology , Shanghai, P.R. China
| | - Ping Gu
- Department of Ophthalmology, Ninth People's Hospital, Shanghai JiaoTong University School of Medicine , Shanghai, P.R. China.,Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology , Shanghai, P.R. China
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Nguyen CH, Glüxam T, Schlerka A, Bauer K, Grandits AM, Hackl H, Dovey O, Zöchbauer-Müller S, Cooper JL, Vassiliou GS, Stoiber D, Wieser R, Heller G. SOCS2 is part of a highly prognostic 4-gene signature in AML and promotes disease aggressiveness. Sci Rep 2019; 9:9139. [PMID: 31235852 PMCID: PMC6591510 DOI: 10.1038/s41598-019-45579-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 06/06/2019] [Indexed: 12/14/2022] Open
Abstract
Acute myeloid leukemia (AML) is a heterogeneous disease with respect to its genetic and molecular basis and to patients´ outcome. Clinical, cytogenetic, and mutational data are used to classify patients into risk groups with different survival, however, within-group heterogeneity is still an issue. Here, we used a robust likelihood-based survival modeling approach and publicly available gene expression data to identify a minimal number of genes whose combined expression values were prognostic of overall survival. The resulting gene expression signature (4-GES) consisted of 4 genes (SOCS2, IL2RA, NPDC1, PHGDH), predicted patient survival as an independent prognostic parameter in several cohorts of AML patients (total, 1272 patients), and further refined prognostication based on the European Leukemia Net classification. An oncogenic role of the top scoring gene in this signature, SOCS2, was investigated using MLL-AF9 and Flt3-ITD/NPM1c driven mouse models of AML. SOCS2 promoted leukemogenesis as well as the abundance, quiescence, and activity of AML stem cells. Overall, the 4-GES represents a highly discriminating prognostic parameter in AML, whose clinical applicability is greatly enhanced by its small number of genes. The newly established role of SOCS2 in leukemia aggressiveness and stemness raises the possibility that the signature might even be exploitable therapeutically.
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Affiliation(s)
- Chi Huu Nguyen
- Department of Medicine I, Division of Oncology, Medical University of Vienna, Vienna, Austria
- Comprehensive Cancer Center, Vienna, Austria
| | - Tobias Glüxam
- Department of Medicine I, Division of Oncology, Medical University of Vienna, Vienna, Austria
- Comprehensive Cancer Center, Vienna, Austria
| | - Angela Schlerka
- Department of Medicine I, Division of Oncology, Medical University of Vienna, Vienna, Austria
- Comprehensive Cancer Center, Vienna, Austria
| | - Katharina Bauer
- Department of Medicine I, Division of Oncology, Medical University of Vienna, Vienna, Austria
- Comprehensive Cancer Center, Vienna, Austria
- Institute of Science and Technology Austria, Vienna, Austria
| | - Alexander M Grandits
- Department of Medicine I, Division of Oncology, Medical University of Vienna, Vienna, Austria
- Comprehensive Cancer Center, Vienna, Austria
| | - Hubert Hackl
- Division of Bioinformatics, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Oliver Dovey
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK
| | - Sabine Zöchbauer-Müller
- Department of Medicine I, Division of Oncology, Medical University of Vienna, Vienna, Austria
- Comprehensive Cancer Center, Vienna, Austria
| | - Jonathan L Cooper
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK
| | - George S Vassiliou
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK
| | - Dagmar Stoiber
- Ludwig Boltzmann Institute for Cancer Research, Vienna, Austria
- Institute of Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Rotraud Wieser
- Department of Medicine I, Division of Oncology, Medical University of Vienna, Vienna, Austria.
- Comprehensive Cancer Center, Vienna, Austria.
| | - Gerwin Heller
- Department of Medicine I, Division of Oncology, Medical University of Vienna, Vienna, Austria.
- Comprehensive Cancer Center, Vienna, Austria.
- Institute of Pharmacology and Toxicology, Department for Biomedical Sciences, University of Veterinary Medicine Vienna, Vienna, Austria.
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Inhibition of microRNA-505 suppressed MPP+ -induced cytotoxicity of SHSY5Y cells in an in vitro Parkinson's disease model. Eur J Pharmacol 2018; 835:11-18. [DOI: 10.1016/j.ejphar.2018.07.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 07/12/2018] [Accepted: 07/13/2018] [Indexed: 01/26/2023]
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Abstract
BACKGROUND Pluripotency is a fundamental property of early mammalian development but it is currently unclear to what extent its cellular mechanisms are conserved in vertebrates or metazoans. POU5F1 and POU2 are the two principle members constituting the class V POU domain family of transcription factors, thought to have a conserved role in the regulation of pluripotency in vertebrates as well as germ cell maintenance and neural patterning. They have undergone a complex pattern of evolution which is poorly understood and controversial. RESULTS By analyzing the sequences of POU5F1, POU2 and their flanking genes, we provide strong indirect evidence that POU5F1 originated at least as early as a common ancestor of gnathostomes but became extinct in a common ancestor of teleost fishes, while both POU5F1 and POU2 survived in the sarcopterygian lineage leading to tetrapods. Less divergent forms of POU5F1 and POU2 appear to have persisted among cartilaginous fishes. CONCLUSIONS Our study resolves the controversial evolutionary relationship between teleost pou2 and tetrapod POU2 and POU5F1, and shows that class V POU transcription factors have existed at least since the common ancestor of gnathostome vertebrates. It provides a framework for elucidating the basis for the lineage-specific extinctions of POU2 and POU5F1.
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Affiliation(s)
- Stephen Frankenberg
- Department of Zoology, University of Melbourne, Melbourne, VIC 3010, Australia.
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6
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Sun Y, Senger K, Baginski TK, Mazloom A, Chinn Y, Pantua H, Hamidzadeh K, Ramani SR, Luis E, Tom I, Sebrell A, Quinones G, Ma Y, Mukhyala K, Sai T, Ding J, Haley B, Shadnia H, Kapadia SB, Gonzalez LC, Hass PE, Zarrin AA. Evolutionarily conserved paired immunoglobulin-like receptor α (PILRα) domain mediates its interaction with diverse sialylated ligands. J Biol Chem 2012; 287:15837-50. [PMID: 22396535 DOI: 10.1074/jbc.m111.286633] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Paired immunoglobulin-like receptor (PILR) α is an inhibitory receptor that recognizes several ligands, including mouse CD99, PILR-associating neural protein, and Herpes simplex virus-1 glycoprotein B. The physiological function(s) of interactions between PILRα and its cellular ligands are not well understood, as are the molecular determinants of PILRα/ligand interactions. To address these uncertainties, we sought to identify additional PILRα ligands and further define the molecular basis for PILRα/ligand interactions. Here, we identify two novel PILRα binding partners, neuronal differentiation and proliferation factor-1 (NPDC1), and collectin-12 (COLEC12). We find that sialylated O-glycans on these novel PILRα ligands, and on known PILRα ligands, are compulsory for PILRα binding. Sialylation-dependent ligand recognition is also a property of SIGLEC1, a member of the sialic acid-binding Ig-like lectins. SIGLEC1 Ig domain shares ∼22% sequence identity with PILRα, an identity that includes a conserved arginine localized to position 97 in mouse and human SIGLEC1, position 133 in mouse PILRα and position 126 in human PILRα. We observe that PILRα/ligand interactions require conserved PILRα Arg-133 (mouse) and Arg-126 (human), in correspondence with a previously reported requirement for SIGLEC1 Arg-197 in SIGLEC1/ligand interactions. Homology modeling identifies striking similarities between PILRα and SIGLEC1 ligand binding pockets as well as at least one set of distinctive interactions in the galactoxyl-binding site. Binding studies suggest that PILRα recognizes a complex ligand domain involving both sialic acid and protein motif(s). Thus, PILRα is evolved to engage multiple ligands with common molecular determinants to modulate myeloid cell functions in anatomical settings where PILRα ligands are expressed.
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Affiliation(s)
- Yonglian Sun
- Department of Immunology, Genentech, South San Francisco, California 94080, USA
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7
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Vanlandingham M, Nguyen TV, Abdul-Rahman OA, Parent A, Zhang J. Phenotypical manifestations of partial trisomy 9 and monosomy 4 in two siblings. Neurol Sci 2008; 29:467-70. [PMID: 19039519 DOI: 10.1007/s10072-008-1016-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2008] [Accepted: 08/28/2008] [Indexed: 11/24/2022]
Abstract
In this case report, we describe two siblings with a previously unreported partial monosomy 4q and partial trisomy 9q. The sibling karyotypes were determined to be 46,XX,der(4)t(4;9)(q33;q33)pat and 46,XY,der(4)t(4;9)-(q33;q33)pat. The siblings share several common pathological features, including VSD, PDA, low-set ears and digit anomalies as well as features consistent with Pierre-Robin syndrome and hydrocephalus. We review previously reported phenotypes associated with monosomy 4q and partial trisomy 9q and discuss potential mechanisms for these morphological insults with particular emphasis on neuropathology.
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Affiliation(s)
- Matthew Vanlandingham
- Department of Neurosurgery, University of Mississippi Medical Center, 2500 N. State Street, Jackson, MS, 39216-4505, USA
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8
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Meurers BH, Zhu C, Fernagut PO, Richter F, Hsia YC, Fleming SM, Oh M, Elashoff D, Dicarlo CD, Seaman RL, Chesselet MF. Low dose rotenone treatment causes selective transcriptional activation of cell death related pathways in dopaminergic neurons in vivo. Neurobiol Dis 2008; 33:182-92. [PMID: 19013527 DOI: 10.1016/j.nbd.2008.10.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2008] [Revised: 10/03/2008] [Accepted: 10/04/2008] [Indexed: 12/21/2022] Open
Abstract
Mitochondrial complex I inhibition has been implicated in the degeneration of midbrain dopaminergic (DA) neurons in Parkinson's disease. However, the mechanisms and pathways that determine the cellular fate of DA neurons downstream of the mitochondrial dysfunction have not been fully identified. We conducted cell-type specific gene array experiments with nigral DA neurons from rats treated with the complex I inhibitor, rotenone, at a dose that does not induce cell death. The genome wide screen identified transcriptional changes in multiple cell death related pathways that are indicative of a simultaneous activation of both degenerative and protective mechanisms. Quantitative PCR analyses of a subset of these genes in different neuronal populations of the basal ganglia revealed that some of the changes are specific for DA neurons, suggesting that these neurons are highly sensitive to rotenone. Our data provide insight into potentially defensive strategies of DA neurons against disease relevant insults.
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Affiliation(s)
- B H Meurers
- Department of Neurology, UCLA, Los Angeles, CA 90095, USA.
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9
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Noda S, Horiguchi K, Ichikawa H, Miyoshi H. Repopulating activity of ex vivo-expanded murine hematopoietic stem cells resides in the CD48-c-Kit+Sca-1+lineage marker- cell population. Stem Cells 2007; 26:646-55. [PMID: 18079432 DOI: 10.1634/stemcells.2007-0623] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A better understanding of the biology of cultured hematopoietic stem cells (HSCs) is required to achieve ex vivo expansion of HSCs. In this study, clonal analysis of the surface phenotype and repopulating activity of ex vivo-expanded murine HSCs was performed. After 7 days of culture with stem cell factor, thrombopoietin, fibroblast growth factor-1, and insulin-like growth factor-2, single CD34-/lowc-Kit+Sca-1+lineage marker- (CD34-KSL) cells gave rise to various numbers of cells. The proportion of KSL cells decreased with increasing number of expanded cells. Transplantation studies revealed that the progeny containing a higher percentage of KSL cells tended to have enhanced repopulating potential. We also found that CD48 was heterogeneously expressed in the KSL cell population after culture. Repopulating activity resided only in the CD48-KSL cell population, which had a relatively long intermitotic interval. Microarray analysis showed surprisingly few differences in gene expression between cultured CD48-KSL cells (cycling HSCs) and CD48+KSL cells (cycling non-HSCs) compared with freshly isolated CD34-KSL cells (quiescent HSCs), suggesting that the maintenance of stem cell activity is controlled by a relatively small number of genes. These findings should lead to a better understanding of ex vivo-expanded HSCs.
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Affiliation(s)
- Shinichi Noda
- Subteam for Manipulation of Cell Fate, RIKEN BioResource Center, 3-1-1 Koyadai, Tsukuba, Ibaraki 305-0074, Japan
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10
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Theodosiou M, Monaghan JR, Spencer ML, Voss SR, Noonan DJ. Isolation and characterization of axolotl NPDC-1 and its effects on retinoic acid receptor signaling. Comp Biochem Physiol B Biochem Mol Biol 2007; 147:260-70. [PMID: 17331771 PMCID: PMC2683337 DOI: 10.1016/j.cbpb.2007.01.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2006] [Revised: 01/19/2007] [Accepted: 01/19/2007] [Indexed: 12/31/2022]
Abstract
Retinoic acid, a key morphogen in early vertebrate development and tissue regeneration, mediates its effects through the binding of receptors that act as ligand-induced transcription factors. These binding events function to recruit an array of transcription co-regulatory proteins to specific gene promoters. One such co-regulatory protein, neuronal proliferation and differentiation control-1 (NPDC-1), is broadly expressed during mammalian development and functions as an in vitro repressor of retinoic acid receptor (RAR)-mediated transcription. To obtain comparative and developmental insights about NPDC-1 function, we cloned the axolotl (Ambystoma mexicanum) orthologue and measured transcript abundances among tissues sampled during the embryonic and juvenile phases of development, and also during spinal cord regeneration. Structurally, the axolotl orthologue of NPDC-1 retained sequence identity to mammalian sequences in all functional domains. Functionally, we observed that axolotl NPDC-1 mRNA expression peaked late in embryogenesis, with highest levels of expression occurring during the time of limb development, a process regulated by retinoic acid signaling. Also similar to what has been observed in mammals, axolotl NPDC-1 directly interacts with axolotl RAR, modulates axolotl RAR DNA binding, and represses cell proliferation and axolotl RAR-mediated gene transcription. These data justify axolotl as a model to further investigate NPDC-1 and its role in regulating retinoic acid signaling.
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Affiliation(s)
- Maria Theodosiou
- : Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536, USA
| | - James R Monaghan
- : Department of Biology, University of Kentucky, Lexington, KY 40506, USA
| | - Michael L Spencer
- : Division of Developmental Biology, Cincinnati Children’s Hospital Research Foundation, Cincinnati, OH 45229, USA
| | - S Randal Voss
- : Department of Biology, University of Kentucky, Lexington, KY 40506, USA
| | - Daniel J Noonan
- : Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536, USA
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11
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Abstract
NPDC-1 is a gene specifically expressed in neural cells when they stop to divide and begin to differentiate. Immunocytochemical study analysis of differentiated PC12 cells transfected with NPDC-tag vectors showed that NPDC-1 is transported in vesicles from the Golgi apparatus to the cell membrane and is then likely internalized into endosomes. The protein colocalized, at least partially, with synaptic vesicle proteins: synaptophysin, synaptobrevin 2, and Rab3 GEP (Rab3 GTP/GDP exchange protein). Moreover, subcellular fractionation of rat brain showed that crude synaptic membrane and crude synaptic vesicle fractions were enriched in NPDC-1. Although NPDC-1 bound Rab3 GEP in vitro, it seems unlikely to be involved in Ca2+-dependent exocytosis and, thus, in synaptic vesicle trafficking.
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Affiliation(s)
- C Evrard
- Laboratoire Biologie Moléculaire et Différenciation, Unité de Génétique Oncologique, CNRS-URA 8125, Institut Gustave Roussy, Villejuif, France.
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12
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Evrard C, Caron S, Rouget P. Functional analysis of the NPDC-1 gene. Gene 2005; 343:153-63. [PMID: 15563841 DOI: 10.1016/j.gene.2004.08.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2004] [Revised: 08/01/2004] [Accepted: 08/19/2004] [Indexed: 10/26/2022]
Abstract
Mouse NPDC-1 (Neural Proliferation Differentiation and Control-1) is specifically expressed in neural cells when they stop dividing and start to differentiate. The NPDC-1 protein has been shown to interact with the E2F1 transcription factor, D-type cyclins and Cdk2. Immunocytochemical studies and subcellular fractionation of rat brains disclosed a partial colocalization of NPDC-1 with synaptic vesicle proteins, suggesting additional functional interactions. Here, we report the characterization of the mouse and human genes that were found to display very similar structures. We mapped the human gene to chromosome 9q34.3. No obvious pathological defect has been previously linked to this region. In order to gain further insights into its function(s), we generated null mice for the NPDC-1 gene. We did not detect any macroscopic phenotypical defect. Analysis of the upstream sequence of the mouse NPDC-1 gene delineated two regions involved in its negative and positive transcriptional regulation. Evidence for the regulation of NPDC-1 by Krox family transcription factors is presented.
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Affiliation(s)
- C Evrard
- Laboratoire Biologie Moléculaire et Différenciation, Unité de Génétique Oncologique, CNRS-UMR 8125, Institut Gustave Roussy, PR-1, 39 rue Camille Desmoulins, 94805 Villejuif Cedex, France.
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13
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Bloomston M, Durkin A, Yang I, Rojiani M, Rosemurgy AS, Enkmann S, Yeatman TJ, Zervos EE. Identification of molecular markers specific for pancreatic neuroendocrine tumors by genetic profiling of core biopsies. Ann Surg Oncol 2004; 11:413-9. [PMID: 15070602 DOI: 10.1245/aso.2004.03.077] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND There is a paucity of known molecular markers that distinguish pancreatic neuroendocrine tumors from other pancreatic tumor types. We hypothesized that novel markers for pancreatic neuroendocrine tumors could be identified with molecular fingerprinting of pooled RNA samples from core biopsies. METHODS Total RNA was harvested from nine core biopsies of normal pancreas, pancreatitis, pancreatic adenocarcinoma, pancreatic adenocarcinoma metastases, and pancreatic neuroendocrine tumors. RNA from each group of samples was pooled and hybridized to an oligonucleotide-based microarray. Four genes (ANG2, NPDC1, ELOVL4, and CALCR) were selected for further investigation by reverse transcriptase polymerase chain reaction from the top 20 highest expressed genes, on the basis of potential as novel markers. RESULTS Neuroendocrine tumors were most unique from normal pancreas. Pancreatitis, pancreatic adenocarcinoma, and metastases are more closely related to each other and to normal pancreas. ANG2 was overexpressed in 89% of neuroendocrine tumors, compared with 22% of normal pancreas, making it the best potential molecular marker or therapeutic target of the four genes selected for analysis. CONCLUSION We have identified a specific set of molecular markers for pancreatic neuroendocrine tumors distinct from pancreatitis and pancreatic adenocarcinoma. These novel markers may prove useful as molecular markers or therapeutic targets unique to pancreatic neuroendocrine tumors.
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Affiliation(s)
- Mark Bloomston
- Surgery, Moffitt Cancer Center, Tampa, Florida 33612, USA
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14
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Spencer ML, Theodosiou M, Noonan DJ. NPDC-1, a novel regulator of neuronal proliferation, is degraded by the ubiquitin/proteasome system through a PEST degradation motif. J Biol Chem 2004; 279:37069-78. [PMID: 15229225 DOI: 10.1074/jbc.m402507200] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Neural proliferation and differentiation control protein-1 (NPDC-1) is a protein expressed primarily in brain and lung and whose expression can be correlated with the regulation of cellular proliferation and differentiation. Embryonic differentiation in brain and lung has classically been linked to retinoid signaling, and we have recently characterized NPDC-1 as a regulator of retinoic acid-mediated events. Regulators of differentiation and development are themselves highly regulated and usually through multiple mechanisms. One such mechanism, protein degradation via the ubiquitin/proteasome degradation pathway, has been linked to the expression of a number of proteins involved in control of proliferation or differentiation, including cyclin D1 and E2F-1. The data presented here demonstrate that NPDC-1 is likewise degraded by the ubiquitin/proteasome system. MG-132, a proteasome inhibitor, stabilized the expression of NPDC-1 and allowed detection of ubiquitinated NPDC-1 in vivo. A PEST motif (rich in proline, glutamine, serine, and threonine) located in the carboxyl terminus of NPDC-1 was shown to target the protein for degradation. Deletion of the PEST motif increased NPDC-1 protein stability and NPDC-1 inhibitory effect on retinoic acid-mediated transcription. NPDC-1 was phosphorylated by several kinases, including extracellular signal-regulated kinase. Phosphorylation of NPDC-1 increased the in vitro rate of NPDC-1 ubiquitination. The MEK inhibitor, PD-98059, an inhibitor of extracellular signal-regulated activation, also inhibited the formation of ubiquitinated NPDC-1 in vivo. Together these results suggest that retinoic acid signaling can be modulated by the presence of NPDC-1 and that the protein level and activity of NPDC-1 can be regulated by phosphorylation-mediated proteasomal degradation.
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Affiliation(s)
- Michael L Spencer
- Department of Molecular and Cellular Biochemistry, University of Kentucky Medical Center, 800 Rose Street, Lexington, KY 40536, USA
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15
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Henry II KW, Spencer ML, Theodosiou M, Lou D, Noonan DJ. A neuronal-specific differentiation protein that directly modulates retinoid receptor transcriptional activation. NUCLEAR RECEPTOR 2003; 1:7. [PMID: 14567757 PMCID: PMC222963 DOI: 10.1186/1478-1336-1-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2003] [Accepted: 09/10/2003] [Indexed: 11/22/2022]
Abstract
Background The specificity of a nuclear receptor's ability to modulate gene expression resides in its ability to bind a specific lipophilic ligand, associate with specific dimerization partners and bind specific DNA sequences in the promoter regions of genes. This sequence of events appears to be the basis for targeting an additional regulatory complex composed of a variety of protein and RNA components that deliver signals for facilitation or inhibition of the RNA polymerase complex. Characterization of the tissue and cell-specific components of these coregulatory complexes appear to be integral to our understanding of nuclear receptor regulation of transcription. Results A novel yeast screen sensitive to retinoid-X receptor (RXR) transcriptional activation resulted in the isolation of the rat homologue of the mouse NPDC-1 gene. NPDC-1 has been shown to be involved in the control of neural cell proliferation and differentiation, possibly through interactions with the cell cycle promoting transcription factor E2F-1. Although the amino acid sequence of NPDC-1 is highly conserved between mouse, rat and human homologues, their tissue specific expression was seen to vary. A potential for direct protein:protein interaction between NPDC-1, RXR and retinoic acid receptor beta (RARβ) was observed in vitro and NPDC-1 facilitated RXR homodimer and RAR-RXR heterodimer DNA binding in vitro. Expression of NPDC-1 was also observed to repress transcription mediated by retinoid receptors as well as by several other nuclear receptor family members, although not in a universal manner. Conclusions These results suggest that NPDC-1, through direct interaction with retinoid receptors, functions to enhance the transcription complex formation and DNA binding function of retinoid receptors, but ultimately repress retinoid receptor-mediated gene expression. As with NPDC-1, retinoids and their receptors have been implicated in brain development and these data provide a point of convergence for NPDC-1 and retinoid mediation of neuronal differentiation.
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Affiliation(s)
- Kenneth W Henry II
- Department of Molecular and Cellular Biochemistry, University of Kentucky, 800 Rose Street, Lexington, KY 40536, USA
| | - Michael L Spencer
- Department of Molecular and Cellular Biochemistry, University of Kentucky, 800 Rose Street, Lexington, KY 40536, USA
| | - Maria Theodosiou
- Department of Molecular and Cellular Biochemistry, University of Kentucky, 800 Rose Street, Lexington, KY 40536, USA
| | - Dingyuan Lou
- Department of Molecular and Cellular Biochemistry, University of Kentucky, 800 Rose Street, Lexington, KY 40536, USA
| | - Daniel J Noonan
- Department of Molecular and Cellular Biochemistry, University of Kentucky, 800 Rose Street, Lexington, KY 40536, USA
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16
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Qu X, Zhang C, Zhai Y, Xing G, Wei H, Yu Y, Wu S, He F. Characterization and tissue expression of a novel human gene npdc1. Gene 2001; 264:37-44. [PMID: 11245976 DOI: 10.1016/s0378-1119(01)00324-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
We report the molecular characterization of a novel human homologue of mouse npdc1 (neural proliferation, differentiation and control, 1) gene, designated human npdc1 (hnpdc1). hnpdc1 was identified by large-scale sequencing of fetal liver cDNA libraries and the full-length cDNA was obtained by PCR amplification. The hnpdc1 gene, which contains nine exons, was mapped to human chromosome 15. It encodes a polypeptide of 325 amino acids, which shows high homology (77% identity) to the mouse NPDC1. Sequence analysis has shown that hNPDC1 protein contains a putative signal peptide of 34 amino acids, a transmembrane segment, and a typical bipartite nuclear localization signal. Northern blot and dot blot hybridization indicates that, just like mnpdc1, hnpdc1 mRNA is strongly expressed in adult brain (especially in hippocampus, frontal lobe and temporal lobe) and about 1.82-fold higher in adult brain than that in fetal brain. Unlike mnpdc1, however, hnpdc1 contains two transcripts instead of only one (1.5 kb), and has high expression levels in prostate, pituitary gland, and mammary glands. These results support that hNPDC1 plays a role in the control of neural cell proliferation and differentiation, and suggest that it may be involved in the development of several secretion glands.
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MESH Headings
- Amino Acid Sequence
- Base Sequence
- Chromosome Mapping
- Chromosomes, Human, Pair 15/genetics
- Cloning, Molecular
- DNA, Complementary/chemistry
- DNA, Complementary/genetics
- DNA, Complementary/isolation & purification
- Exons
- Female
- Gene Expression
- Gene Expression Regulation, Developmental
- Genes/genetics
- Humans
- Introns
- Male
- Molecular Sequence Data
- Nerve Tissue Proteins/genetics
- RNA/genetics
- RNA/metabolism
- Radiation Hybrid Mapping
- Sequence Alignment
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Tissue Distribution
- Transcription, Genetic
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Affiliation(s)
- X Qu
- Department of Genomics and Proteomics, Beijing Institute of Radiation Medicine, Chinese National Human Genome Center at Beijing, 27 Taiping Road, 100850, P.R., Beijing, China
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17
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Sansal I, Dupont E, Toru D, Evrard C, Rouget P. NPDC-1, a regulator of neural cell proliferation and differentiation, interacts with E2F-1, reduces its binding to DNA and modulates its transcriptional activity. Oncogene 2000; 19:5000-9. [PMID: 11042687 DOI: 10.1038/sj.onc.1203843] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We have previously identified NPDC-1, a neural factor involved in the control of proliferation and differentiation, and we have shown that the stable introduction of NPDC-1 into transformed cells down-regulates cell proliferation both by increasing the generation time and by suppressing transformed properties. The data presented here indicate that, in vitro, NPDC-1 is able to interact with the transcription factor E2F-1 and some cell cycle proteins, such as D-cyclins and cdk2. In addition, two-hybrid experiments in mammalian cells show that the interaction between NPDC-1 and E2F-1 can also occur in vivo. This interaction reduces the binding of E2F-1 to DNA and its transcriptional activity. Taken together, the data suggest that NPDC-1 could influence cell cycle progression and neural differentiation through its association with E2F-1.
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Affiliation(s)
- I Sansal
- Unité de Génétique Oncologique, CNRS-UMR-1599, Institut Gustave Roussy, PR-1, 39 rue Camille Desmoulins, 94805 Villejuif Cedex, France
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18
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Iwasaki K, Toyonaga R. The Rab3 GDP/GTP exchange factor homolog AEX-3 has a dual function in synaptic transmission. EMBO J 2000; 19:4806-16. [PMID: 10970871 PMCID: PMC302062 DOI: 10.1093/emboj/19.17.4806] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Guanine nucleotide exchange is essential for Rab GTPase activities in regulating intracellular vesicle trafficking. This exchange process is facilitated by guanine nucleotide exchange factor (GEF). Previously, we identified Caenorhabditis elegans AEX-3 as a GEF for Rab3 GTPase. Here we demonstrate that AEX-3 regulates neural activities through a second, previously unrecognized pathway via interactions with the novel protein CAB-1. CAB-1 is 425 amino acids long and has an 80 amino acid motif in common with the mouse neural protein NPDC-1. cab-1 and rab-3 mutants have different behavioral defects, and RAB-3 localization and function are apparently normal in cab-1 mutants, indicating that the CAB-1 pathway is distinct from the RAB-3 pathway. The aex-3 mutant phenotype resembles the sum of the rab-3 and cab-1 mutant phenotypes, indicating that AEX-3 regulates two different pathways for neural activities. We propose that connection of multiple pathways may be an important feature of Rab GEFs to coordinate various cellular events.
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Affiliation(s)
- K Iwasaki
- Laboratory of Molecular Neurobiology, National Institute of Bioscience and Human Technology, 1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan.
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19
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Dupont E, Sansal I, Evrard C, Rouget P. Developmental pattern of expression of NPDC-1 and its interaction with E2F-1 suggest a role in the control of proliferation and differentiation of neural cells. J Neurosci Res 1998; 51:257-67. [PMID: 9469579 DOI: 10.1002/(sici)1097-4547(19980115)51:2<257::aid-jnr14>3.0.co;2-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
We have previously identified NPDC-1, a gene specifically expressed in neural cells and involved in the control of cell proliferation and differentiation. In the present study, we have investigated the expression of this gene during mouse development and the interactions of the NPDC-1 protein with cell cycle regulatory proteins. The data show that NPDC-1 mRNA begins to be expressed in a variety of neural structures when the precursors enter into their terminal differentiation. They also indicate that in adult brain, the expression patterns of NPDC-1 and E2F-1 mRNA largely overlap. In addition, the NPDC-1 protein is able to interact directly with the transcription factor E2F-1 that participates in the regulation of the cell cycle, cell survival, and apoptosis. The present results suggest that NPDC-1 might be involved in the terminal differentiation and survival of neural cells and might act through interactions with E2F-1.
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Affiliation(s)
- E Dupont
- Unité de Génétique Oncologique, CNRS-URA 1967, Institut Gustave Roussy, Villejuif, France
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