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Li S, Zhai J, Xu B, Liu J, Chu W, Wang D, Geng X, Chen ZJ, Du Y. Erythropoietin-producing hepatocellular receptor A7 restrains estrogen negative feedback of luteinizing hormone via ephrin A5 in the hypothalamus of female rats. Am J Physiol Endocrinol Metab 2020; 319:E81-E90. [PMID: 32396496 DOI: 10.1152/ajpendo.00046.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We have previously shown that systemic injection of erythropoietin-producing hepatocellular receptor A7 (EPHA7)-Fc raises serum luteinizing hormone (LH) levels before ovulation in female rats, indicating the induction of EPHA7 in ovulation. In this study, we aimed to identify the mechanism and hypothalamus-pituitary-ovary (HPO) axis level underlying the promotion of LH secretion by EPHA7. Using an ovariectomized (OVX) rat model, in conjunction with low-dose 17β-estradiol (E2) treatment, we investigated the association between EPHA7-ephrin (EFN)A5 signaling and E2 negative feedback. Various rat models (OVX, E2-treated OVX, and abarelix treated) were injected with the recombinant EPHA7-Fc protein through the caudal vein to investigate the molecular mechanism underlying the promotion of LH secretion by EPHA7. Efna5 was observed strongly expressed in the arcuate nucleus of the female rat by using RNAscope in situ hybridization. Our results indicated that E2, combined with estrogen receptor (ER)α, but not ERβ, inhibited Efna5 and gonadotropin-releasing hormone 1 (Gnrh1) expressions in the hypothalamus. In addition, the systemic administration of EPHA7-Fc restrained the inhibition of Efna5 and Gnrh1 by E2, resulting in increased Efna5 and Gnrh1 expressions in the hypothalamus as well as increased serum LH levels. Collectively, our findings demonstrated the involvement of EPHA7-EFNA5 signaling in the regulation of LH and the E2 negative feedback pathway in the hypothalamus, highlighting the functional role of EPHA7 in female reproduction.
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Affiliation(s)
- Shang Li
- Center for Reproductive Medicine, Ren Ji Hospital, School of Medicine, Shanghai, Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics, Shanghai, China
| | - Junyu Zhai
- Center for Reproductive Medicine, Ren Ji Hospital, School of Medicine, Shanghai, Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics, Shanghai, China
| | - Bing Xu
- Center for Reproductive Medicine, Ren Ji Hospital, School of Medicine, Shanghai, Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics, Shanghai, China
| | - Jiansheng Liu
- Center for Reproductive Medicine, Ren Ji Hospital, School of Medicine, Shanghai, Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics, Shanghai, China
| | - Weiwei Chu
- Center for Reproductive Medicine, Ren Ji Hospital, School of Medicine, Shanghai, Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics, Shanghai, China
| | - Dongshuang Wang
- Center for Reproductive Medicine, Ren Ji Hospital, School of Medicine, Shanghai, Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics, Shanghai, China
| | - Xueying Geng
- Center for Reproductive Medicine, Ren Ji Hospital, School of Medicine, Shanghai, Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics, Shanghai, China
| | - Zi-Jiang Chen
- Center for Reproductive Medicine, Ren Ji Hospital, School of Medicine, Shanghai, Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics, Shanghai, China
- Center for Reproductive Medicine, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
- National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Shandong University, Jinan, Shandong, China
- Key laboratory of Reproductive Endocrinology of Ministry of Education, Shandong University, Jinan, Shandong, China
| | - Yanzhi Du
- Center for Reproductive Medicine, Ren Ji Hospital, School of Medicine, Shanghai, Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics, Shanghai, China
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2
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Wang X, Sun J, Wang Z, Li C, Mao B. EphA7 is required for otic epithelial homeostasis by modulating Claudin6 in Xenopus. Biochem Biophys Res Commun 2020; 526:375-380. [PMID: 32222280 DOI: 10.1016/j.bbrc.2020.03.099] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 03/18/2020] [Indexed: 12/20/2022]
Abstract
Receptor tyrosine kinase EphA7 is specifically expressed in otic region in Xenopus early development. However, its role in otocyst development remains unknown. Knockdown of EphA7 by a specific morpholino oligonucleotide (MO) reduced the size of the otocyst and triggered otic epithelial cell extrusion. Interestingly, EphA7 depletion attenuated the membrane level of the tight junction protein Claudin6 (CLDN6). Utilizing the Cldn6 MO, we further confirmed that CLDN6 attenuation also led to otic epithelial cell extrusion. Our work suggested that EphA7 modulates the otic epithelial homeostasis through stabilizing the CLDN6 membrane level.
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Affiliation(s)
- Xiaolei Wang
- Medical College, Qingdao University, Qingdao, 266071, China; State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223, China
| | - Jian Sun
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223, China; Cancer and Developmental Biology Laboratory, National Cancer Institute, National Institute of Health, Frederick, MD, 21702, USA
| | - Zhaobao Wang
- School of Control Science and Engineering, Shandong University, Jinan, 250061, China; Energy-rich Compounds Production by Photosynthetic Carbon Fixation Research Center, College of Life Sciences, Qingdao Agricultural University, Qingdao, 266109, China
| | - Chaocui Li
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223, China
| | - Bingyu Mao
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223, China.
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3
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Großkopf AK, Schlagowski S, Hörnich BF, Fricke T, Desrosiers RC, Hahn AS. EphA7 Functions as Receptor on BJAB Cells for Cell-to-Cell Transmission of the Kaposi's Sarcoma-Associated Herpesvirus and for Cell-Free Infection by the Related Rhesus Monkey Rhadinovirus. J Virol 2019; 93:e00064-19. [PMID: 31118261 PMCID: PMC6639272 DOI: 10.1128/jvi.00064-19] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 05/15/2019] [Indexed: 12/18/2022] Open
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV) is the causative agent of Kaposi's sarcoma and is associated with two B cell malignancies, primary effusion lymphoma (PEL) and the plasmablastic variant of multicentric Castleman's disease. On several adherent cell types, EphA2 functions as a cellular receptor for the gH/gL glycoprotein complex of KSHV. KSHV gH/gL also has previously been found to interact weakly with other members of the Eph family of receptor tyrosine kinases (Ephs), and other A-type Ephs have been shown to be able to compensate for the absence of EphA2 using overexpression systems. However, whether these interactions are of functional consequence at endogenous protein levels has remained unclear so far. Here, we demonstrate for the first time that endogenously expressed EphA7 in BJAB B cells is critical for the cell-to-cell transmission of KSHV from producer iSLK cells to BJAB target cells. The BJAB lymphoblastoid cell line often serves as a model for B cell infection and expresses only low levels of all Eph family receptors other than EphA7. Endogenous EphA7 could be precipitated from the cellular lysate of BJAB cells using recombinant gH/gL, and knockout of EphA7 significantly reduced transmission of KSHV into BJAB target cells. Knockout of EphA5, the second most expressed A-type Eph in BJAB cells, had a similar, although less pronounced, effect on KSHV infection. Receptor function of EphA7 was conserved for cell-free infection by the related rhesus monkey rhadinovirus (RRV), which is relatively even more dependent on EphA7 for infection of BJAB cells.IMPORTANCE Infection of B cells is relevant for two KSHV-associated malignancies, the plasmablastic variant of multicentric Castleman's disease and PEL. Therefore, elucidating the process of B cell infection is important for the understanding of KSHV pathogenesis. While the high-affinity receptor for the gH/gL glycoprotein complex, EphA2, has been shown to function as an entry receptor for various types of adherent cells, the gH/gL complex can also interact with other Eph receptor tyrosine kinases with lower avidity. We analyzed the Eph interactions required for infection of BJAB cells, a model for B cell infection by KSHV. We identified EphA7 as the principal Eph receptor for infection of BJAB cells by KSHV and the related rhesus monkey rhadinovirus. While two analyzed PEL cell lines exhibited high EphA2 and low EphA7 expression, a third PEL cell line, BCBL-1, showed high EphA7 and low EphA2 expression, indicating a possible relevance for KSHV pathology.
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MESH Headings
- Animals
- B-Lymphocytes/metabolism
- B-Lymphocytes/pathology
- B-Lymphocytes/virology
- Cell Line, Tumor
- Herpesvirus 8, Human/genetics
- Herpesvirus 8, Human/metabolism
- Herpesvirus 8, Human/physiology
- Humans
- Lymphoma, Primary Effusion/metabolism
- Lymphoma, Primary Effusion/pathology
- Macaca mulatta
- Receptor, EphA7/genetics
- Receptor, EphA7/metabolism
- Receptors, Virus/genetics
- Receptors, Virus/metabolism
- Rhadinovirus/genetics
- Rhadinovirus/metabolism
- Rhadinovirus/physiology
- Viral Envelope Proteins/genetics
- Viral Envelope Proteins/metabolism
- Virus Internalization
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Affiliation(s)
- Anna K Großkopf
- Junior Research Group Herpesviruses, German Primate Center-Leibniz Institute for Primate Research, Göttingen, Germany
| | - Sarah Schlagowski
- Junior Research Group Herpesviruses, German Primate Center-Leibniz Institute for Primate Research, Göttingen, Germany
| | - Bojan F Hörnich
- Junior Research Group Herpesviruses, German Primate Center-Leibniz Institute for Primate Research, Göttingen, Germany
| | - Thomas Fricke
- Junior Research Group Herpesviruses, German Primate Center-Leibniz Institute for Primate Research, Göttingen, Germany
| | - Ronald C Desrosiers
- Department of Pathology, Miller School of Medicine, University of Miami, Miami, Florida, USA
| | - Alexander S Hahn
- Junior Research Group Herpesviruses, German Primate Center-Leibniz Institute for Primate Research, Göttingen, Germany
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4
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Konze SA, Cajic S, Oberbeck A, Hennig R, Pich A, Rapp E, Buettner FFR. Quantitative Assessment of Sialo-Glycoproteins and N-Glycans during Cardiomyogenic Differentiation of Human Induced Pluripotent Stem Cells. Chembiochem 2017; 18:1317-1331. [PMID: 28509371 DOI: 10.1002/cbic.201700100] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Indexed: 12/25/2022]
Abstract
Human induced pluripotent stem-cell-derived cardiomyocytes (hiPSC CMs) may be used in regenerative medicine for individualized tissue transplants in the future. For application in patients, the generated CMs have to be highly pure and well characterized. In order to overcome the prevalent scarcity of CM-specific markers, we quantitatively assessed cell-surface-exposed sialo-glycoproteins and N-glycans of hiPSCs, CM progenitors, and CMs. Applying a combination of metabolic labeling and specific sialo-glycoprotein capture, we could highly enrich and quantify membrane proteins during cardiomyogenic differentiation. Among them we identified a number of novel, putative biomarkers for hiPSC CMs. Analysis of the N-glycome by capillary gel electrophoresis revealed three novel structures comprising β1,3-linked galactose, α2,6-linked sialic acid and complex fucosylation; these were highly specific for hiPSCs. Bisecting GlcNAc structures strongly increased during differentiation, and we propose that they are characteristic of early, immature CMs.
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Affiliation(s)
- Sarah A Konze
- Institute of Clinical Biochemistry, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625, Hannover, Germany
- REBIRTH Cluster of Excellence, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625, Hannover, Germany
| | - Samanta Cajic
- Max Planck Institute for Dynamics of Complex Technical Systems, Sandtorstrasse 1, 39106, Magdeburg, Germany
| | - Astrid Oberbeck
- Institute of Clinical Biochemistry, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625, Hannover, Germany
- REBIRTH Cluster of Excellence, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625, Hannover, Germany
| | - René Hennig
- Max Planck Institute for Dynamics of Complex Technical Systems, Sandtorstrasse 1, 39106, Magdeburg, Germany
- glyXera GmbH, Leipziger Strasse 44, 39120, Magdeburg, Germany
| | - Andreas Pich
- Institute of Toxicology, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625, Hannover, Germany
| | - Erdmann Rapp
- Max Planck Institute for Dynamics of Complex Technical Systems, Sandtorstrasse 1, 39106, Magdeburg, Germany
- glyXera GmbH, Leipziger Strasse 44, 39120, Magdeburg, Germany
| | - Falk F R Buettner
- Institute of Clinical Biochemistry, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625, Hannover, Germany
- REBIRTH Cluster of Excellence, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625, Hannover, Germany
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5
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Wu X, Yan L, Liu Y, Xian W, Wang L, Ding X. MicroRNA-448 suppresses osteosarcoma cell proliferation and invasion through targeting EPHA7. PLoS One 2017; 12:e0175553. [PMID: 28604772 PMCID: PMC5467824 DOI: 10.1371/journal.pone.0175553] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 03/28/2017] [Indexed: 12/19/2022] Open
Abstract
Osteosarcoma is the most common type of malignant bone tumor, often affecting adolescents and children. MicroRNAs (miRNAs) are a group of small, non-protein coding, endogenous RNAs that play critical roles in osteosarcoma tumorigenesis. In our study, we demonstrated that miR-448 expression was downregulated in osteosarcoma tissues and cell lines. Overexpression of miR-448 suppressed osteosarcoma cell proliferation, colony formation and migration. Moreover, we found that EPHA7 was a direct target gene of miR-448 in osteosarcoma cells. We further demonstrated that the EPHA7 expression level was upregulated in osteosarcoma tissues. Interestingly, the expression level of EPHA7 was inversely correlated with the expression level of miR-448 in osteosarcoma tissues. In addition, elevated expression of miR-448 suppressed osteosarcoma cell proliferation and invasion through targeting EPHA7. Taken together, these findings suggest that miR-448 functioned as a tumor suppressor gene in the development of osteosarcoma through targeting EPHA7.
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Affiliation(s)
- Xiangkun Wu
- Department of Orthopaedic Surgery, Nanyang Second People's Hospital, Nanyang, Henan, China
| | - Lihua Yan
- Department of Medical Oncology, Nanyang Second People's Hospital, Nanyang, Henan, China
- * E-mail:
| | - Yongxi Liu
- Department of Orthopaedic Surgery, Nanyang Second People's Hospital, Nanyang, Henan, China
| | - Wenfeng Xian
- Department of Orthopaedic Surgery, Nanyang Second People's Hospital, Nanyang, Henan, China
| | - Liuyu Wang
- Department of Orthopaedic Surgery, Nanyang Second People's Hospital, Nanyang, Henan, China
| | - Xunmeng Ding
- Department of Orthopaedic Surgery, Nanyang Second People's Hospital, Nanyang, Henan, China
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6
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Kim Y, Park E, Park S. Identification of the 187 bp EphA7 Genomic DNA as the Dorsal Midline-Specific Enhancer of the Diencephalon and Mesencephalon. Mol Cells 2015; 38:1007-12. [PMID: 26537192 PMCID: PMC4673404 DOI: 10.14348/molcells.2015.0221] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 09/08/2015] [Indexed: 12/19/2022] Open
Abstract
EphA7 is a key molecule in regulating the development of the dien- and mesencephalon. To get insight into the mechanism of how EphA7 gene expression is regulated during the dorsal specification of the dien- and mesencephalon, we investigated the cis-acting regulatory sequence driving EphA7 to the dorsal midline of the dien- and mesencephalon. Transgenic LacZ reporter analysis, using overlapping EphA7 BACs, was used to narrow down the dorsal midline-specific enhancer, revealing the 25.3 kb genomic region as the enhancer candidate. Strikingly, this genomic DNA was located far downstream of the EphA7 transcription start site, +302.6 kb to +327.9 kb. Further enhancer mapping, using comparative genomic analysis and transgenic methods, showed that the 187 bp genomic DNA alone, approximately 305 kb downstream of the EphA7 transcription start site, was sufficient to act as the dorsal midline-specific enhancer of EphA7. Importantly, our results indicate that the 187 bp dorsal midline-specific enhancer is critically regulated by homeobox transcription factors during the development of the dien- and mesencephalon.
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MESH Headings
- Animals
- Base Sequence
- Chick Embryo
- Chromosomes, Artificial, Bacterial/genetics
- Conserved Sequence
- DNA/genetics
- Diencephalon/embryology
- Enhancer Elements, Genetic/physiology
- Gene Expression Regulation, Developmental
- Genes, Reporter
- Homeodomain Proteins/metabolism
- Mesencephalon/embryology
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Molecular Sequence Data
- Promoter Regions, Genetic
- Receptor, EphA7/genetics
- Sequence Analysis, DNA
- Transcription Factors/metabolism
- Transcription Initiation Site
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Affiliation(s)
- Yujin Kim
- Department of Biological Science, Sookmyung Women’s University, Seoul 140-742,
Korea
| | - Eunjeong Park
- Department of Biological Science, Sookmyung Women’s University, Seoul 140-742,
Korea
| | - Soochul Park
- Department of Biological Science, Sookmyung Women’s University, Seoul 140-742,
Korea
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7
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Lee J, Nakajima-Koyama M, Sone M, Koga M, Ebisuya M, Yamamoto T, Nishida E. Secreted Ephrin Receptor A7 Promotes Somatic Cell Reprogramming by Inducing ERK Activity Reduction. Stem Cell Reports 2015; 5:480-9. [PMID: 26441306 PMCID: PMC4625027 DOI: 10.1016/j.stemcr.2015.09.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Revised: 09/02/2015] [Accepted: 09/02/2015] [Indexed: 11/30/2022] Open
Abstract
The role of secreted molecules in cellular reprogramming has been poorly understood. Here we identify a truncated form of ephrin receptor A7 (EPHA7) as a key regulator of reprogramming. Truncated EPHA7 is prominently upregulated and secreted during reprogramming. EPHA7 expression is directly regulated by OCT3/4. EphA7 knockdown results in marked reduction of reprogramming efficiency, and the addition of truncated EPHA7 is able to restore it. ERK activity is markedly reduced during reprogramming, and the secreted, truncated EPHA7 is responsible for ERK activity reduction. Remarkably, treatment of EphA7-knockdown MEFs with the ERK pathway inhibitor restores reprogramming efficiency. Analyses show that truncated EPHA7-induced ERK activity reduction plays an important role in the middle phase of reprogramming. Thus, our findings uncover the importance of secreted EPHA7-induced ERK activity reduction in reprogramming. EPHA7 is prominently upregulated during reprogramming Secreted, truncated EPHA7 contributes to promoting reprogramming Truncated EPHA7 drives reprogramming by inducing ERK1/2 activity reduction Truncated EPHA7 plays an important role in the middle phase of reprogramming
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Affiliation(s)
- Joonseong Lee
- Department of Cell and Developmental Biology, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - May Nakajima-Koyama
- Department of Cell and Developmental Biology, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan; JST, CREST, Chiyoda-ku, Tokyo 102-0075, Japan
| | - Masamitsu Sone
- Department of Reprogramming Science, Center for iPS Cell Research and Application, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan; Institute for Integrated Cell-Material Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan
| | - Makito Koga
- Department of Cell and Developmental Biology, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan; RIKEN Center for Developmental Biology, Kobe 650-0047, Japan
| | - Miki Ebisuya
- RIKEN Center for Developmental Biology, Kobe 650-0047, Japan; JST, CREST, Chiyoda-ku, Tokyo 102-0075, Japan
| | - Takuya Yamamoto
- Department of Reprogramming Science, Center for iPS Cell Research and Application, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan; Institute for Integrated Cell-Material Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan; JST, CREST, Chiyoda-ku, Tokyo 102-0075, Japan
| | - Eisuke Nishida
- Department of Cell and Developmental Biology, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan; JST, CREST, Chiyoda-ku, Tokyo 102-0075, Japan.
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8
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Zou J, Yin F, Wang Q, Zhang W, Li L. Analysis of microarray-identified genes and microRNAs associated with drug resistance in ovarian cancer. Int J Clin Exp Pathol 2015; 8:6847-6858. [PMID: 26261572 PMCID: PMC4525906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 05/25/2015] [Indexed: 06/04/2023]
Abstract
The aim of this study was to identify potential microRNAs and genes associated with drug resistance in ovarian cancer through web-available microarrays. The drug resistant-related microRNA microarray dataset GS54665 and mRNA dataset GSE33482, GSE28646, and GSE15372 were downloaded from the Gene Expression Omnibus database. Dysregulated microRNAs/genes were screened with GEO2R and were further identified in SKOV3 (SKOV3/DDP) and A2780 (A2780/DDP) cells by real-time quantitative PCR (qRT-PCR), and then their associations with drug resistance was analyzed by comprehensive bioinformatic analyses. Nine microRNAs (microRNA-199a-5p, microRNA-199a-3p, microRNA-199b-3p, microRNA-215, microRNA-335, microRNA-18b, microRNA-363, microRNA-645 and microRNA-141) and 38 genes were identified to be differentially expressed in drug-resistant ovarian cancer cells, with seven genes (NHSL1, EPHA3, USP51, ZSCAN4, EPHA7, SNCA and PI15) exhibited exactly the same expression trends in all three microarrays. Biological process annotation and pathway enrichment analysis of the 9 microRNAs and 38 genes identified several drug resistant-related signaling pathways, and the microRNA-mRNA interaction revealed the existence of a targeted regulatory relationship between the 9 microRNAs and most of the 38 genes. The expression of 9 microRNAs and the 7 genes by qRT-PCR in SKOV3/DDP and A2780/DDP cells indicating a consistent expression profile with the microarrays. Among those, the expression of EPHA7 and PI15 were negatively correlated with that of microRNA-141, and they were also identified as potential targets of this microRNA via microRNA-mRNA interaction. We thus concluded that microRNA-141, EPHA7, and PI15 might jointly participate in the regulation of drug resistance in ovarian cancer and serve as potential targets in targeted therapies.
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Affiliation(s)
- Jing Zou
- Department of Gynecologic Oncology, Affiliated Tumor Hospital of Guangxi Medical UniversityNanning 530021, Guangxi, P.R. China
| | - Fuqiang Yin
- Medical Scientific Research Centre, Guangxi Medical UniversityNanning 530021, Guangxi, P.R. China
| | - Qi Wang
- Department of Gynecologic Oncology, Affiliated Tumor Hospital of Guangxi Medical UniversityNanning 530021, Guangxi, P.R. China
| | - Wei Zhang
- Department of Gynecologic Oncology, Affiliated Tumor Hospital of Guangxi Medical UniversityNanning 530021, Guangxi, P.R. China
| | - Li Li
- Department of Gynecologic Oncology, Affiliated Tumor Hospital of Guangxi Medical UniversityNanning 530021, Guangxi, P.R. China
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9
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Lee H, Park E, Kim Y, Park S. EphrinA5-EphA7 complex induces apoptotic cell death via TNFR1. Mol Cells 2013; 35:450-5. [PMID: 23657875 PMCID: PMC3887865 DOI: 10.1007/s10059-013-0072-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Revised: 03/14/2013] [Accepted: 03/14/2013] [Indexed: 10/26/2022] Open
Abstract
A previous study showed that the EphA7 receptor regulates apoptotic cell death during early brain development. In this study, we provide evidence that the EphA7 receptor interacts with death receptors such as tumor necrosis factor receptor 1 (TNFR1) to decrease cell viability. We showed that ephrinA5 stimulates EphA7 to activate the TNFR1-mediated apoptotic signaling pathway. In addition, a pull-down assay using biotinylated ephrinA5-Fc revealed that ephrinA5-EphA7 complexes recruit TNFR1 to form a multi-protein complex. Immunocytochemical staining analysis showed that EphA7 was co-localized with TNFR1 on the cell surface when cells were incubated with ephrinA5 at low temperatures. Finally, both the internalization motif and death domain of TNFR1 was important for interacting with an intracytoplasmic region of EphA7; this interaction was essential for inducing the apoptotic signaling cascade. This result suggests that a distinct multi-protein complex comprising ephrinA5, EphA7, and TNFR1 may constitute a platform for inducing caspase-dependent apoptotic cell death.
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Affiliation(s)
- Haeryung Lee
- Department of Biological Science, Sookmyung Women’s University, Seoul 140-742,
Korea
| | - Eunjeong Park
- Department of Biological Science, Sookmyung Women’s University, Seoul 140-742,
Korea
| | - Yujin Kim
- Department of Biological Science, Sookmyung Women’s University, Seoul 140-742,
Korea
| | - Soochul Park
- Department of Biological Science, Sookmyung Women’s University, Seoul 140-742,
Korea
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10
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López-Nieva P, Vaquero C, Fernández-Navarro P, González-Sánchez L, Villa-Morales M, Santos J, Esteller M, Fernández-Piqueras J. EPHA7, a new target gene for 6q deletion in T-cell lymphoblastic lymphomas. Carcinogenesis 2012; 33:452-8. [PMID: 22114070 DOI: 10.1093/carcin/bgr271] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Cryptic deletions at chromosome 6q are common cytogenetic abnormalities in T-cell lymphoblastic leukemia/lymphoma (T-LBL), but the target genes have not been formally identified. Our results build on detection of specific chromosomal losses in a mouse model of γ-radiation-induced T-LBLs and provide interesting clues for new putative susceptibility genes in a region orthologous to human 6q15-6q16.3. Among these, Epha7 emerges as a bona fide candidate tumor suppressor gene because it is inactivated in practically all the T-LBLs analyzed (100% in mouse and 95.23% in human). We provide evidence showing that Epha7 downregulation may occur, at least in part, by loss of heterozygosity (19.35% in mouse and 12.5% in human) or promoter hypermethylation (51.61% in mouse and 43.75% in human) or a combination of both mechanisms (12.90% in mouse and 6.25% in human). These results indicate that EPHA7 might be considered a new tumor suppressor gene for 6q deletions in T-LBLs. Notably, this gene is located in 6q16.1 proximal to GRIK2 and CASP8AP2, other candidate genes identified in this region. Thus, del6q seems to be a complex region where inactivation of multiple genes may cooperatively contribute to the onset of T-cell lymphomas.
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MESH Headings
- Animals
- Calcium-Binding Proteins/genetics
- Cell Line, Tumor
- Chromosome Deletion
- Chromosomes, Human, Pair 4
- Chromosomes, Human, Pair 6/genetics
- DNA Methylation
- Down-Regulation
- Female
- Genes, Tumor Suppressor
- Humans
- Jurkat Cells
- Leukemia, T-Cell/genetics
- Leukemia-Lymphoma, Adult T-Cell/genetics
- Loss of Heterozygosity
- Lymphoma, T-Cell/genetics
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Promoter Regions, Genetic
- Receptor, EphA7/genetics
- Receptors, Kainic Acid/genetics
- Sequence Deletion
- GluK2 Kainate Receptor
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Affiliation(s)
- Pilar López-Nieva
- Departmento Biología Celular e Inmunología, Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049 Madrid, Spain
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11
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Bonifaci N, Górski B, Masojć B, Wokołorczyk D, Jakubowska A, Dębniak T, Berenguer A, Serra Musach J, Brunet J, Dopazo J, Narod SA, Lubiński J, Lázaro C, Cybulski C, Pujana MA. Exploring the link between germline and somatic genetic alterations in breast carcinogenesis. PLoS One 2010; 5:e14078. [PMID: 21124932 PMCID: PMC2989917 DOI: 10.1371/journal.pone.0014078] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Accepted: 11/02/2010] [Indexed: 12/19/2022] Open
Abstract
Recent genome-wide association studies (GWASs) have identified candidate genes contributing to cancer risk through low-penetrance mutations. Many of these genes were unexpected and, intriguingly, included well-known players in carcinogenesis at the somatic level. To assess the hypothesis of a germline-somatic link in carcinogenesis, we evaluated the distribution of somatic gene labels within the ordered results of a breast cancer risk GWAS. This analysis suggested frequent influence on risk of genetic variation in loci encoding for "driver kinases" (i.e., kinases encoded by genes that showed higher somatic mutation rates than expected by chance and, therefore, whose deregulation may contribute to cancer development and/or progression). Assessment of these predictions using a population-based case-control study in Poland replicated the association for rs3732568 in EPHB1 (odds ratio (OR) = 0.79; 95% confidence interval (CI): 0.63-0.98; P(trend) = 0.031). Analyses by early age at diagnosis and by estrogen receptor α (ERα) tumor status indicated potential associations for rs6852678 in CDKL2 (OR = 0.32, 95% CI: 0.10-1.00; P(recessive) = 0.044) and rs10878640 in DYRK2 (OR = 2.39, 95% CI: 1.32-4.30; P(dominant) = 0.003), and for rs12765929, rs9836340, rs4707795 in BMPR1A, EPHA3 and EPHA7, respectively (ERα tumor status P(interaction)<0.05). The identification of three novel candidates as EPH receptor genes might indicate a link between perturbed compartmentalization of early neoplastic lesions and breast cancer risk and progression. Together, these data may lay the foundations for replication in additional populations and could potentially increase our knowledge of the underlying molecular mechanisms of breast carcinogenesis.
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Affiliation(s)
- Núria Bonifaci
- Biomarkers and Susceptibility Unit, Spanish Biomedical Research Centre Network for Epidemiology and Public Health, Catalan Institute of Oncology, L'Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), L'Hospitalet, Barcelona, Spain
| | - Bohdan Górski
- Department of Genetics and Pathology, International Hereditary Cancer Center, Pomeranian Medical University, Szczecin, Poland
| | - Bartlomiej Masojć
- Department of Genetics and Pathology, International Hereditary Cancer Center, Pomeranian Medical University, Szczecin, Poland
| | - Dominika Wokołorczyk
- Department of Genetics and Pathology, International Hereditary Cancer Center, Pomeranian Medical University, Szczecin, Poland
| | - Anna Jakubowska
- Department of Genetics and Pathology, International Hereditary Cancer Center, Pomeranian Medical University, Szczecin, Poland
| | - Tadeusz Dębniak
- Department of Genetics and Pathology, International Hereditary Cancer Center, Pomeranian Medical University, Szczecin, Poland
| | - Antoni Berenguer
- Biomarkers and Susceptibility Unit, Spanish Biomedical Research Centre Network for Epidemiology and Public Health, Catalan Institute of Oncology, L'Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), L'Hospitalet, Barcelona, Spain
| | - Jordi Serra Musach
- Biomarkers and Susceptibility Unit, Spanish Biomedical Research Centre Network for Epidemiology and Public Health, Catalan Institute of Oncology, L'Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), L'Hospitalet, Barcelona, Spain
| | - Joan Brunet
- Hereditary Cancer Programme, Catalan Institute of Oncology, IdIBGi, Girona, Spain
| | - Joaquín Dopazo
- Department of Bioinformatics and Genomics, Centro de Investigación Príncipe Felipe, Functional Genomics Node and Spanish Biomedical Research Centre Network for Rare Diseases, Valencia, Spain
| | - Steven A. Narod
- Womens College Research Institute, University of Toronto and Women's College Hospital, Toronto, Ontario, Canada
| | - Jan Lubiński
- Department of Genetics and Pathology, International Hereditary Cancer Center, Pomeranian Medical University, Szczecin, Poland
| | - Conxi Lázaro
- Hereditary Cancer Programme, Catalan Institute of Oncology, IDIBELL, L'Hospitalet, Barcelona, Spain
| | - Cezary Cybulski
- Department of Genetics and Pathology, International Hereditary Cancer Center, Pomeranian Medical University, Szczecin, Poland
| | - Miguel Angel Pujana
- Biomarkers and Susceptibility Unit, Spanish Biomedical Research Centre Network for Epidemiology and Public Health, Catalan Institute of Oncology, L'Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), L'Hospitalet, Barcelona, Spain
- Translational Research Laboratory, Catalan Institute of Oncology, IDIBELL, L'Hospitalet, Barcelona, Spain
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12
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Shaut CA, Saneyoshi C, Morgan EA, Knosp WM, Sexton DR, Stadler HS. HOXA13 directly regulates EphA6 and EphA7 expression in the genital tubercle vascular endothelia. Dev Dyn 2007; 236:951-60. [PMID: 17304517 DOI: 10.1002/dvdy.21077] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Hypospadias, a common defect affecting the growth and closure of the external genitalia, is often accompanied by gross enlargements of the genital tubercle (GT) vasculature. Because Hoxa13 homozygous mutant mice also exhibit hypospadias and GT vessel expansion, we examined whether genes playing a role in angiogenesis exhibit reduced expression in the GT. From this analysis, reductions in EphA6 and EphA7 were detected. Characterization of EphA6 and EphA7 expression in the GT confirmed colocalization with HOXA13 in the GT vascular endothelia. Analysis of the EphA6 and EphA7 promoter regions revealed a series of highly conserved cis-regulatory elements bound by HOXA13 with high affinity. GT chromatin immunoprecipitation confirmed that HOXA13 binds these gene-regulatory elements in vivo. In vitro, HOXA13 activates gene expression through the EphA6 and EphA7 gene-regulatory elements. Together these findings indicate that HOXA13 directly regulates EphA6 and EphA7 in the developing GT and identifies the GT vascular endothelia as a novel site for HOXA13-dependent expression of EphA6 and EphA7.
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MESH Headings
- Animals
- Base Sequence
- Binding Sites
- Cells, Cultured
- Endothelium, Vascular/embryology
- Endothelium, Vascular/metabolism
- Gene Expression Regulation, Developmental
- Genitalia/blood supply
- Genitalia/embryology
- Genitalia/metabolism
- Green Fluorescent Proteins/genetics
- Green Fluorescent Proteins/metabolism
- Homeodomain Proteins/genetics
- Homeodomain Proteins/metabolism
- Homeodomain Proteins/physiology
- Mice
- Mice, Mutant Strains
- Molecular Sequence Data
- Promoter Regions, Genetic
- Receptor, EphA6/genetics
- Receptor, EphA6/metabolism
- Receptor, EphA7/genetics
- Receptor, EphA7/metabolism
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/metabolism
- Sequence Homology, Nucleic Acid
- Transfection
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Affiliation(s)
- Carley A Shaut
- Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, Oregon
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13
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Zhao X, Sun M, Zhao J, Leyva JA, Zhu H, Yang W, Zeng X, Ao Y, Liu Q, Liu G, Lo WHY, Jabs EW, Amzel LM, Shan X, Zhang X. Mutations in HOXD13 underlie syndactyly type V and a novel brachydactyly-syndactyly syndrome. Am J Hum Genet 2007; 80:361-71. [PMID: 17236141 PMCID: PMC1785357 DOI: 10.1086/511387] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2006] [Accepted: 11/22/2006] [Indexed: 11/03/2022] Open
Abstract
HOXD13, the homeobox-containing gene located at the most 5' end of the HOXD cluster, plays a critical role in limb development. It has been shown that mutations in human HOXD13 can give rise to limb malformations, with variable expressivity and a wide spectrum of clinical manifestations. Polyalanine expansions in HOXD13 cause synpolydactyly, whereas amino acid substitutions in the homeodomain are associated with brachydactyly types D and E. We describe two large Han Chinese families with different limb malformations, one with syndactyly type V and the other with limb features overlapping brachydactyly types A4, D, and E and mild syndactyly of toes 2 and 3. Two-point linkage analysis showed LOD scores >3 (theta =0) for markers within and/or flanking the HOXD13 locus in both families. In the family with syndactyly type V, we identified a missense mutation in the HOXD13 homeodomain, c.950A-->G (p.Q317R), which leads to substitution of the highly conserved glutamine that is important for DNA-binding specificity and affinity. In the family with complex brachydactyly and syndactyly, we detected a deletion of 21 bp in the imperfect GCN (where N denotes A, C, G, or T) triplet-containing exon 1 of HOXD13, which results in a polyalanine contraction of seven residues. Moreover, we found that the mutant HOXD13 with the p.Q317R substitution was unable to transactivate the human EPHA7 promoter. Molecular modeling data supported these experimental results. The calculated interactions energies were in agreement with the measured changes of the activity. Our data established the link between HOXD13 and two additional limb phenotypes--syndactyly type V and brachydactyly type A4--and demonstrated that a polyalanine contraction in HOXD13, most likely, led to other digital anomalies but not to synpolydactyly. We suggest the term "HOXD13 limb morphopathies" for the spectrum of limb disorders caused by HOXD13 mutations.
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Affiliation(s)
- Xiuli Zhao
- Department of Medical Genetics and National Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing China
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14
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Dawson DW, Hong JS, Shen RR, French SW, Troke JJ, Wu YZ, Chen SS, Gui D, Regelson M, Marahrens Y, Morse HC, Said J, Plass C, Teitell MA. Global DNA methylation profiling reveals silencing of a secreted form of Epha7 in mouse and human germinal center B-cell lymphomas. Oncogene 2007; 26:4243-52. [PMID: 17260020 PMCID: PMC2756834 DOI: 10.1038/sj.onc.1210211] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Most human lymphomas originate from transformed germinal center (GC) B lymphocytes. While activating mutations and translocations of MYC, BCL2 and BCL6 promote specific GC lymphoma subtypes, other genetic and epigenetic modifications that contribute to malignant progression in the GC remain poorly defined. Recently, aberrant expression of the TCL1 proto-oncogene was identified in major GC lymphoma subtypes. TCL1 transgenic mice offer unique models of both aggressive GC and marginal zone B-cell lymphomas, further supporting a role for TCL1 in B-cell transformation. Here, restriction landmark genomic scanning was employed to discover tumor-associated epigenetic alterations in malignant GC and marginal zone B-cells in TCL1 transgenic mice. Multiple genes were identified that underwent DNA hypermethylation and decreased expression in TCL1 transgenic tumors. Further, we identified a secreted isoform of EPHA7, a member of the Eph family of receptor tyrosine kinases that are able to influence tumor invasiveness, metastasis and neovascularization. EPHA7 was hypermethylated and repressed in both mouse and human GC B-cell non-Hodgkin lymphomas, with the potential to influence tumor progression and spread. These data provide the first set of hypermethylated genes with the potential to complement TCL1-mediated GC B-cell transformation and spread.
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Affiliation(s)
- DW Dawson
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - JS Hong
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - RR Shen
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - SW French
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - JJ Troke
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Y-Z Wu
- Molecular Virology, Immunology and Medical Genetics, Division of Human Cancer Genetics, The Ohio State University, Columbus, OH, USA
| | - S-S Chen
- Molecular Virology, Immunology and Medical Genetics, Division of Human Cancer Genetics, The Ohio State University, Columbus, OH, USA
| | - D Gui
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - M Regelson
- Department of Human Genetics, The David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Y Marahrens
- Department of Human Genetics, The David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - HC Morse
- Laboratory of Immunopathology, National Institute of Allergy and Infectious Disease, National Institutes of Health, Rockville, MD, USA
| | - J Said
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - C Plass
- Molecular Virology, Immunology and Medical Genetics, Division of Human Cancer Genetics, The Ohio State University, Columbus, OH, USA
| | - MA Teitell
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
- Molecular Biology Institute, Institute for Stem Cell Biology and Medicine, California NanoSystems Institute, Institute for Cell Mimetic Studies and Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, CA, USA
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15
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Figueroa JD, Benton RL, Velazquez I, Torrado AI, Ortiz CM, Hernandez CM, Diaz JJ, Magnuson DS, Whittemore SR, Miranda JD. Inhibition of EphA7 up-regulation after spinal cord injury reduces apoptosis and promotes locomotor recovery. J Neurosci Res 2007; 84:1438-51. [PMID: 16983667 DOI: 10.1002/jnr.21048] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Functional impairment after spinal cord injury (SCI) is partially attributed to neuronal cell death, with further degeneration caused by the accompanying apoptosis of myelin-forming oligodendrocytes. The Eph receptor protein tyrosine kinase family and its cognate ligands, the ephrins, have been identified to be involved in axonal outgrowth, synapse formation, and target recognition, mainly mediated by repulsive activity. Recent reports suggest that ephrin/Eph signaling might also play a role as a physiological trigger for apoptosis during embryonic development. Here, we investigated the expression profile of EphA7, after SCI, by using a combination of quantitative real-time PCR (QRT-PCR) and immunohistochemical techniques. QRT-PCR analysis showed an increase in the expression of full-length EphA7 at 7 days postinjury (DPI). Receptor immunoreactivity was shown mostly in astrocytes of the white matter at the injury epicenter. In control animals, EphA7 expression was observed predominantly in motor neurons of the ventral gray matter, although some immunoreactivity was seen in white matter. Furthermore, blocking the expression of EphA7 after SCI using antisense oligonucleotides resulted in significant acceleration of hindlimb locomotor recovery at 1 week. This was a transient effect; by 2 weeks postinjury, treated animals were not different from controls. Antisense treatment also produced a return of nerve conduction, with shorter latencies than in control treated animals after transcranial magnetic stimulation. We identified EphA7 receptors as putative regulators of apoptosis in the acute phase after SCI. These results suggest a functional role for EphA7 receptors in the early stages of SCI pathophysiology.
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Affiliation(s)
- Johnny D Figueroa
- Department of Physiology, University of Puerto Rico Medical Science Campus, San Juan, Puerto Rico
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16
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García-Calero E, de Puelles E, Puelles L. EphA7 receptor is expressed differentially at chicken prosomeric boundaries. Neuroscience 2006; 141:1887-97. [PMID: 16844303 DOI: 10.1016/j.neuroscience.2006.04.074] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2006] [Revised: 04/05/2006] [Accepted: 04/07/2006] [Indexed: 10/24/2022]
Abstract
We reexamined tyrosine-kinase receptor EphA7 RNA signal in embryonic chicken forebrain, to clarify its topographic relationships with early regionalization processes, such as establishment of prosomeric boundaries. After neurulation, uniform alar expression appears across prospective prosomeres prosomere 1, prosomere 2 and prosomere 3 (prethalamus, thalamus and pretectum). This pattern soon changes by differential downregulation at or in between some of the prosomeric boundaries in an individual pattern for each limit, and by expansion of expression into the rostral midbrain. The secondary distribution highlights various transversal and longitudinal domains, notably the zona limitans intrathalamica and the pretectum limits, as well as two longitudinal bands in the basal plate, termed paramedian and parabasal. Strong expression of EphA7 appears at the mammillary pouch and a supramammillary tegmental arch from stage Hamburger and Hamilton stages 14-15 onwards. At the end of the developmental period examined, expression of EphA7 in the ventricular zone decreases generally (with some exceptions) and novel expression domains start to appear in the mantle layer, initiating a third phase of differential expression. Thus, while the expression of EphA7 does not show a fixed functional or topographic relationship to prosomeric boundaries, sequential transcription changes during chicken development are consistent with a differential involvement of the diverse interprosomeric boundaries, as well as dorsoventral patterning organizers, in the regulation of EphA7 expression.
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Affiliation(s)
- E García-Calero
- Department of Human Anatomy and Psychobiology, School of Medicine, University of Murcia (Campus Espinardo), E30100 Murcia, Spain
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17
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Wang J, Kataoka H, Suzuki M, Sato N, Nakamura R, Tao H, Maruyama K, Isogaki J, Kanaoka S, Ihara M, Tanaka M, Kanamori M, Nakamura T, Shinmura K, Sugimura H. Downregulation of EphA7 by hypermethylation in colorectal cancer. Oncogene 2005; 24:5637-47. [PMID: 16007213 DOI: 10.1038/sj.onc.1208720] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A significant reduction of EphA7 expression in human colorectal cancers was shown using semiquantitative reverse transcription-polymerase chain reaction analysis in 59 colorectal cancer tissues, compared to corresponding normal mucosas (P=0.008), and five colon cancer cell lines. To investigate the mechanism of EphA7 downregulation in colorectal cancer, we examined the methylation status of the 5'CpG island around the translation start site in five colon cancer cell lines using restriction enzymes, methylation-specific PCR, and bisulfite sequencing and found evidence of aberrant methylation. The expression of EphA7 in colon cancer cell lines was restored after treatment with 5-aza-2'-deoxycytidine. Analysis of methylation status in totally 75 tumors compared to clinicopathological parameters revealed that hypermethylation of colorectal cancers was more frequent in male than in female (P=0.0078), and in moderately differentiated than in well-differentiated adenocarcinomas (P=0.0361). There was a tendency that hypermethylation in rectal cancers was more frequent than in colon cancers (P=0.0816). Hypermethylation was also observed in colorectal adenomas. This is the first report describing the downregulation of an Eph family gene in a solid tumor via aberrant 5'CpG island methylation. It provides the evidence that EphA7 gene is involved in human colorectal carcinogenesis.
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Affiliation(s)
- Jiandong Wang
- Department of Pathology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Hamamatsu 431-3192, Japan
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18
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Caronia G, Goodman FR, McKeown CME, Scambler PJ, Zappavigna V. An I47L substitution in the HOXD13 homeodomain causes a novel human limb malformation by producing a selective loss of function. Development 2003; 130:1701-12. [PMID: 12620993 DOI: 10.1242/dev.00396] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The 5' members of the Hoxa and Hoxd gene clusters play major roles in vertebrate limb development. One such gene, HOXD13, is mutated in the human limb malformation syndrome synpolydactyly. Both polyalanine tract expansions and frameshifting deletions in HOXD13 cause similar forms of this condition, but it remains unclear whether other kinds of HOXD13 mutations could produce different phenotypes. We describe a six-generation family in which a novel combination of brachydactyly and central polydactyly co-segregates with a missense mutation that substitutes leucine for isoleucine at position 47 of the HOXD13 homeodomain. We compared the HOXD13(I47L) mutant protein both in vitro and in vivo to the wild-type protein and to an artificial HOXD13 mutant, HOXD13(IQN), which is completely unable to bind DNA. We found that the mutation causes neither a dominant-negative effect nor a gain of function, but instead impairs DNA binding at some sites bound by wild-type HOXD13. Using retrovirus-mediated misexpression in developing chick limbs, we showed that wild-type HOXD13 could upregulate chick EphA7 in the autopod, but that HOXD13(I47L) could not. In the zeugopod, however, HOXD13(I47L) produced striking changes in tibial morphology and ectopic cartilages, which were never produced by HOXD13(IQN), consistent with a selective rather than generalised loss of function. Thus, a mutant HOX protein that recognises only a subset of sites recognised by the wild-type protein causes a novel human malformation, pointing to a hitherto undescribed mechanism by which missense mutations in transcription factors can generate unexpected phenotypes. Intriguingly, both HOXD13(I47L) and HOXD13(IQN) produced more severe shortening in proximal limb regions than did wild-type HOXD13, suggesting that functional suppression of anterior Hox genes by more posterior ones does not require DNA binding and is mediated by protein:protein interactions.
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Affiliation(s)
- Giuliana Caronia
- Department of Molecular Biology and Functional Genomics, DIBIT-H San Raffaele, Via Olgettina 58, 20132 Milano, Italy
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