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Zhang JJ, Cao ZF, Zhou BT, Yang JH, Li Z, Lin S, Chen XL, Zhang NW, Ye Q, Ma X, Zhu YH. Abnormal function of EPHA2/p.R957P mutant in congenital cataract. Int J Ophthalmol 2024; 17:1007-1017. [PMID: 38895685 PMCID: PMC11144770 DOI: 10.18240/ijo.2024.06.04] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 03/18/2024] [Indexed: 06/21/2024] Open
Abstract
AIM To identify genetic defects in a Chinese family with congenital posterior polar cataracts and assess the pathogenicity. METHODS A four-generation Chinese family affected with autosomal dominant congenital cataract was recruited. Nineteen individuals took part in this study including 5 affected and 14 unaffected individuals. Sanger sequencing targeted hot-spot regions of 27 congenital cataract-causing genes for variant discovery. The pathogenicity of the variant was evaluated by the guidelines of American College of Medical Genetics and InterVar software. Confocal microscopy was applied to detect the subcellular localization of fluorescence-labeled ephrin type-A receptor 2 (EPHA2). Co-immunoprecipitation assay was implemented to estimate the interaction between EphA2 and other lens membrane proteins. The mRNA and protein expression were analyzed by reverse transcription-polymerase chain reaction (qRT-PCR) and Western blotting assay, respectively. The cell migration was analyzed by wound healing assay. Zebrafish model was generated by ectopic expression of human EPHA2/p.R957P mutant to demonstrate whether the mutant could cause lens opacity in vivo. RESULTS A novel missense and pathogenic variant c.2870G>C was identified in the sterile alpha motif (SAM) domain of EPHA2. Functional studies demonstrated the variant's impact: reduced EPHA2 protein expression, altered subcellular localization, and disrupted interactions with other lens membrane proteins. This mutant notably enhanced human lens epithelial cell migration, and induced a central cloudy region and roughness in zebrafish lenses with ectopic expression of human EPHA2/p.R957P mutant under differential interference contrast (DIC) optics. CONCLUSION Novel pathogenic c.2870G>C variant of EPHA2 in a Chinese congenital cataract family contributes to disease pathogenesis.
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Affiliation(s)
- Jing-Jin Zhang
- Department of Ophthalmology, the First Affiliated Hospital of Fujian Medical University; Fujian Institute of Ophthalmology; Fujian Provincial Clinical Medical Research Center of Eye Diseases and Optometry, Fuzhou 350005, Fujian Province, China
- Department of Ophthalmology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, Fujian Province, China
| | - Zong-Fu Cao
- Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100000, China
- National Human Genetic Resources Center, National Research Institute for Family Planning, Beijing 100081, China
| | - Bi-Ting Zhou
- Department of Ophthalmology, the First Affiliated Hospital of Fujian Medical University; Fujian Institute of Ophthalmology; Fujian Provincial Clinical Medical Research Center of Eye Diseases and Optometry, Fuzhou 350005, Fujian Province, China
- Department of Ophthalmology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, Fujian Province, China
| | - Ju-Hua Yang
- Department of Ophthalmology, the First Affiliated Hospital of Fujian Medical University; Fujian Institute of Ophthalmology; Fujian Provincial Clinical Medical Research Center of Eye Diseases and Optometry, Fuzhou 350005, Fujian Province, China
- Department of Ophthalmology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, Fujian Province, China
- Department of Bioengineering and Biopharmaceutics, School of Pharmacy, Fujian Medical University, Fuzhou 350004, Fujian Province, China
| | - Zhong Li
- Department of Bioengineering and Biopharmaceutics, School of Pharmacy, Fujian Medical University, Fuzhou 350004, Fujian Province, China
| | - Shuang Lin
- Department of Bioengineering and Biopharmaceutics, School of Pharmacy, Fujian Medical University, Fuzhou 350004, Fujian Province, China
| | - Xiao-Le Chen
- Department of Bioengineering and Biopharmaceutics, School of Pharmacy, Fujian Medical University, Fuzhou 350004, Fujian Province, China
| | - Nan-Wen Zhang
- Department of Bioengineering and Biopharmaceutics, School of Pharmacy, Fujian Medical University, Fuzhou 350004, Fujian Province, China
| | - Qin Ye
- Department of Ophthalmology, the First Affiliated Hospital of Fujian Medical University; Fujian Institute of Ophthalmology; Fujian Provincial Clinical Medical Research Center of Eye Diseases and Optometry, Fuzhou 350005, Fujian Province, China
- Department of Ophthalmology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, Fujian Province, China
| | - Xu Ma
- Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100000, China
- National Human Genetic Resources Center, National Research Institute for Family Planning, Beijing 100081, China
| | - Yi-Hua Zhu
- Department of Ophthalmology, the First Affiliated Hospital of Fujian Medical University; Fujian Institute of Ophthalmology; Fujian Provincial Clinical Medical Research Center of Eye Diseases and Optometry, Fuzhou 350005, Fujian Province, China
- Department of Ophthalmology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, Fujian Province, China
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Nehal M, Khatoon J, Akhtar S, Khan MKA. Exploring the potential of EphA2 receptor signaling pathway: a comprehensive review in cancer treatment. Mol Biol Rep 2024; 51:337. [PMID: 38393520 DOI: 10.1007/s11033-024-09298-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2023] [Accepted: 01/29/2024] [Indexed: 02/25/2024]
Abstract
The protein encoded by the ephrin type-A receptor 2 (EphA2) gene is a member of the ephrin receptor subfamily of the receptor tyrosine kinase family (RTKs). Eph receptors play a significant role in various biological processes, particularly cancer progression, development, and pathogenesis. They have been observed to regulate cancer cell growth, migration, invasion, tumor development, invasiveness, angiogenesis, and metastasis. To target EphA2 activity, various molecular, genetic, biochemical, and pharmacological strategies have been extensively tested in laboratory cultures and animal models. Notably, drugs, such as dasatinib, initially designed to target the kinase family, have demonstrated an additional capability to target EphA2 activity. Additionally, a novel monoclonal antibody named EA5 has emerged as a promising option to counteract the effects of EphA2 overexpression and restore tamoxifen sensitivity in EphA2-transfected MCF-7 cells during in vitro experiments. This antibody mimicked the binding of Ephrin A to EphA2. These methods offer potential avenues for inhibiting EphA2 activity, which could significantly decelerate breast cancer progression and restore sensitivity to certain drugs. This review article comprehensively covers EphA2's involvement in multiple malignancies, including ovarian, colorectal, breast, lung, glioma, and melanoma. Furthermore, we discuss the structure of EphA2, the Eph-Ephrin signaling pathway, various EphA2 inhibitors, and the mechanisms of EphA2 degradation. This article provides an extensive overview of EphA2's vital role in different types of cancers and outlines potential therapeutic approaches to target EphA2, shedding light on the underlying molecular mechanisms that make it an attractive target for cancer treatment.
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Affiliation(s)
- Mohd Nehal
- Department of Biosciences, Integral University, Lucknow, Uttar Pradesh, 226026, India
| | - Jahanarah Khatoon
- Department of Biosciences, Integral University, Lucknow, Uttar Pradesh, 226026, India
| | - Salman Akhtar
- Department of Bioengineering, Integral University, Lucknow, Uttar Pradesh, 226026, India
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Mutation of the EPHA2 Tyrosine-Kinase Domain Dysregulates Cell Pattern Formation and Cytoskeletal Gene Expression in the Lens. Cells 2021; 10:cells10102606. [PMID: 34685586 PMCID: PMC8534143 DOI: 10.3390/cells10102606] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 09/20/2021] [Accepted: 09/27/2021] [Indexed: 12/13/2022] Open
Abstract
Genetic variations in ephrin type-A receptor 2 (EPHA2) have been associated with inherited and age-related forms of cataract in humans. Here, we have characterized the eye lens phenotype and transcript profile of germline Epha2 knock-in mutant mice homozygous for either a missense variant associated with age-related cataract in humans (Epha2-Q722) or a novel insertion-deletion mutation (Epha2-indel722) that were both located within the tyrosine-kinase domain of EPHA2. Confocal imaging of ex vivo lenses from Epha2-indel722 mice on a fluorescent reporter background revealed misalignment of epithelial-to-fiber cell meridional-rows at the lens equator and severe disturbance of Y-suture formation at the lens poles, whereas Epha2-Q722 lenses displayed mild disturbance of posterior sutures. Immunofluorescent labeling showed that EPHA2 was localized to radial columns of hexagonal fiber cell membranes in Epha2-Q722 lenses, whereas Epha2-indel722 lenses displayed disorganized radial cell columns and cytoplasmic retention of EPHA2. Immunoprecipitation/blotting studies indicated that EPHA2 formed strong complexes with Src kinase and was mostly serine phosphorylated in the lens. RNA sequencing analysis revealed differential expression of several cytoskeleton-associated genes in Epha2-mutant and Epha2-null lenses including shared downregulation of Lgsn and Clic5. Collectively, our data suggest that mutations within the tyrosine-kinase domain of EPHA2 result in lens cell patterning defects and dysregulated expression of several cytoskeleton-associated proteins.
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Lin Z, Wu Z, Luo W. A Novel Treatment for Ewing's Sarcoma: Chimeric Antigen Receptor-T Cell Therapy. Front Immunol 2021; 12:707211. [PMID: 34566963 PMCID: PMC8461297 DOI: 10.3389/fimmu.2021.707211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Accepted: 08/27/2021] [Indexed: 11/13/2022] Open
Abstract
Ewing's sarcoma (EWS) is a malignant and aggressive tumor type that predominantly occurs in children and adolescents. Traditional treatments such as surgery, radiotherapy and chemotherapy, while successful in the early disease stages, are ineffective in patients with metastases and relapses who often have poor prognosis. Therefore, new treatments for EWS are needed to improve patient's outcomes. Chimeric antigen receptor (CAR)-T cells therapy, a novel adoptive immunotherapy, has been developing over the past few decades, and is increasingly popular in researches and treatments of various cancers. CAR-T cell therapy has been approved by the Food and Drug Administration (FDA) for the treatment of leukemia and lymphoma. Recently, this therapeutic approach has been employed for solid tumors including EWS. In this review, we summarize the safety, specificity and clinical transformation of the treatment targets of EWS, and point out the directions for further research.
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Affiliation(s)
- Zili Lin
- Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha, China
| | - Ziyi Wu
- Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha, China
| | - Wei Luo
- Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha, China
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Lin Z, Wu Z, Luo W. Chimeric Antigen Receptor T-Cell Therapy: The Light of Day for Osteosarcoma. Cancers (Basel) 2021; 13:cancers13174469. [PMID: 34503279 PMCID: PMC8431424 DOI: 10.3390/cancers13174469] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 08/24/2021] [Accepted: 08/28/2021] [Indexed: 01/14/2023] Open
Abstract
Simple Summary As a novel immunotherapy, chimeric antigen receptor (CAR) T-cell therapy has achieved encouraging results in leukemia and lymphoma. Furthermore, CAR-T cells have been explored in the treatment of osteosarcoma (OS). However, there is no strong comprehensive evidence to support their efficacy. Therefore, we reviewed the current evidence on CAR-T cells for OS to demonstrate their feasibility and provide new options for the treatment of OS. Abstract Osteosarcoma (OS) is the most common malignant bone tumor, arising mainly in children and adolescents. With the introduction of multiagent chemotherapy, the treatments of OS have remarkably improved, but the prognosis for patients with metastases is still poor, with a five-year survival rate of 20%. In addition, adverse effects brought by traditional treatments, including radical surgery and systemic chemotherapy, may seriously affect the survival quality of patients. Therefore, new treatments for OS await exploitation. As a novel immunotherapy, chimeric antigen receptor (CAR) T-cell therapy has achieved encouraging results in treating cancer in recent years, especially in leukemia and lymphoma. Furthermore, researchers have recently focused on CAR-T therapy in solid tumors, including OS. In this review, we summarize the safety, specificity, and clinical transformation of the targets in treating OS and point out the direction for further research.
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London M, Gallo E. The EphA2 and cancer connection: potential for immune-based interventions. Mol Biol Rep 2020; 47:8037-8048. [PMID: 32990903 DOI: 10.1007/s11033-020-05767-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 08/28/2020] [Indexed: 12/18/2022]
Abstract
The Eph (erythropoietin-producing human hepatocellular) receptors form the largest known subfamily of receptor tyrosine kinases. These receptors interact with membrane-bound ephrin ligands via direct cell-cell interactions resulting in bi-directional activation of signal pathways. Importantly, the Eph receptors play critical roles in embryonic tissue organization and homeostasis, and in the maintenance of adult processes such as long-term potentiation, angiogenesis, and stem cell differentiation. The Eph receptors also display properties of both tumor promoters and suppressors depending on the cellular context. Characterization of EphA2 receptor in regard to EphA2 dysregulation has revealed associations with various pathological processes, especially cancer. The analysis of various tumor types generally identify EphA2 receptor as overexpressed and/or mutated, and for certain types of cancers EphA2 is linked with poor prognosis and decreased patient survival. Thus, here we highlight the role of EphA2 in malignant tissues that are specific to cancer; these include glioblastoma multiforme, prostate cancer, ovarian and uterine cancers, gastric carcinoma, melanoma, and breast cancer. Due to its large extracellular domain, therapeutic targeting of EphA2 with monoclonal antibodies (mAbs), which may function as inhibitors of ligand activation or as molecular agonists, has been an oft-attempted strategy. Therefore, we review the most current mAb-based therapies against EphA2 expressing cancers currently in pre-clinical and/or clinical stages. Finally, we discuss the latest peptides and cyclical-peptides that function as selective agonists for EphA2 receptor.
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Affiliation(s)
- Max London
- Department of Molecular Genetics, University of Toronto, Donnelly Centre, 160 College Street, Toronto, ON, M5S 3E1, Canada
| | - Eugenio Gallo
- Department of Molecular Genetics, University of Toronto, Donnelly Centre, 160 College Street, Toronto, ON, M5S 3E1, Canada.
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Mudd GE, Brown A, Chen L, van Rietschoten K, Watcham S, Teufel DP, Pavan S, Lani R, Huxley P, Bennett GS. Identification and Optimization of EphA2-Selective Bicycles for the Delivery of Cytotoxic Payloads. J Med Chem 2020; 63:4107-4116. [PMID: 32202781 DOI: 10.1021/acs.jmedchem.9b02129] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Bicycles are constrained bicyclic peptides that represent a promising binding modality for use in targeted drug conjugates. A phage display screen against EphA2, a receptor tyrosine kinase highly expressed in a number of solid tumors, identified a number of Bicycle families with low nanomolar affinity. A Bicycle toxin conjugate (BTC) was generated by derivatization of one of these Bicycles with the potent cytotoxin DM1 via a cleavable linker. This BTC demonstrated potent antitumor activity in vivo but was poorly tolerated, which was hypothesized to be the result of undesired liver uptake caused by poor physicochemical properties. Chemical optimization of a second Bicycle, guided by structural biology, provided a high affinity, metabolically stable Bicycle with improved physicochemical properties. A BTC incorporating this Bicycle also demonstrated potent antitumor activity and was very well tolerated when compared to the initial BTC. Phage display selection followed by chemical optimization of Bicycles can deliver potent drug conjugates with favorable pharmaceutical properties.
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Affiliation(s)
- Gemma E Mudd
- BicycleTx Limited, Building 900, Babraham Research Campus, Cambridge CB22 3AT, United Kingdom
| | - Amy Brown
- BicycleTx Limited, Building 900, Babraham Research Campus, Cambridge CB22 3AT, United Kingdom
| | - Liuhong Chen
- BicycleTx Limited, Building 900, Babraham Research Campus, Cambridge CB22 3AT, United Kingdom
| | | | - Sophie Watcham
- BicycleTx Limited, Building 900, Babraham Research Campus, Cambridge CB22 3AT, United Kingdom
| | - Daniel P Teufel
- BicycleTx Limited, Building 900, Babraham Research Campus, Cambridge CB22 3AT, United Kingdom
| | - Silvia Pavan
- BicycleTx Limited, Building 900, Babraham Research Campus, Cambridge CB22 3AT, United Kingdom
| | - Rachid Lani
- BicycleTx Limited, Building 900, Babraham Research Campus, Cambridge CB22 3AT, United Kingdom
| | - Philip Huxley
- BicycleTx Limited, Building 900, Babraham Research Campus, Cambridge CB22 3AT, United Kingdom
| | - Gavin S Bennett
- BicycleTx Limited, Building 900, Babraham Research Campus, Cambridge CB22 3AT, United Kingdom
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Darling TK, Lamb TJ. Emerging Roles for Eph Receptors and Ephrin Ligands in Immunity. Front Immunol 2019; 10:1473. [PMID: 31333644 PMCID: PMC6620610 DOI: 10.3389/fimmu.2019.01473] [Citation(s) in RCA: 126] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 06/13/2019] [Indexed: 12/30/2022] Open
Abstract
Eph receptors are the largest family of receptor tyrosine kinases and mediate a myriad of essential processes in humans from embryonic development to adult tissue homeostasis through interactions with membrane-bound ephrin ligands. The ubiquitous expression of Eph receptors and ephrin ligands among the cellular players of the immune system underscores the importance of these molecules in orchestrating an optimal immune response. This review provides an overview of the various roles of Eph receptors and ephrin ligands in immune cell development, activation, and migration. We also discuss the role of Eph receptors in disease pathogenesis as well as the implications of Eph receptors as future immunotherapy targets. Given the diverse and critical roles of Eph receptors and ephrin ligands throughout the immune system during both resting and activated states, this review aims to highlight the critical yet underappreciated roles of this family of signaling molecules in the immune system.
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Affiliation(s)
- Thayer K Darling
- Immunology and Molecular Pathogenesis Program, Emory University Laney Graduate School, Atlanta, GA, United States.,Department of Pathology, University of Utah, Salt Lake City, UT, United States
| | - Tracey J Lamb
- Department of Pathology, University of Utah, Salt Lake City, UT, United States
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Blumenthal MJ, Schutz C, Meintjes G, Mohamed Z, Mendelson M, Ambler JM, Whitby D, Mackelprang RD, Carse S, Katz AA, Schäfer G. EPHA2 sequence variants are associated with susceptibility to Kaposi's sarcoma-associated herpesvirus infection and Kaposi's sarcoma prevalence in HIV-infected patients. Cancer Epidemiol 2018; 56:133-139. [PMID: 30176543 PMCID: PMC6206435 DOI: 10.1016/j.canep.2018.08.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 08/20/2018] [Accepted: 08/21/2018] [Indexed: 12/20/2022]
Abstract
BACKGROUND To determine if variations exist in the KSHV host receptor EPHA2's coding region that affect KSHV infectivity and/or KS prevalence among South African HIV-infected patients. METHODS A retrospective candidate gene association study was performed on 150 patients which were randomly selected from a total of 756 HIV-infected patients and grouped according to their KS status and KSHV serodiagnosis; namely group 1: KS+/KSHV+; group 2: KS-/KSHV+; group 3: KS-/KSHV-. Peripheral blood DNA was used to extract DNA and PCR amplify and sequence the entire EPHA2 coding region, which was compared to the NCBI reference through multiple alignment. RESULTS 100% (95% CI 92.9-100%) of the KS positive patients, and 31.6% (95% CI 28.3-35.1%) of the KS negative patients were found to be KSHV seropositive. Aggregate variation across the entire EPHA2 coding region identified an association with KS (OR = 6.6 (95% CI 2.8, 15.9), p = 2.2 × 10-5). This was primarily driven by variation in the functionally important protein tyrosine kinase domain (Pkinase-Tyr; OR = 4.9 (95% CI 1.9, 12.4), p = 0.001) and the sterile-α-motif (SAM; OR = 13.8 (95% CI 1.7, 111.6), p = 0.014). Mutation analysis revealed two novel, non-synonymous heterozygous variants (c.2254 T > C: OR undefined, adj. p = 0.02; and c.2990 G > T: OR undefined, adj. p = 0.04) in Pkinase-Tyr and SAM, respectively, to be statistically associated with KS; and a novel heterozygous transition (c.2727C > T: OR = 6.4 (95% CI 1.4, 28.4), adj. p = 0.03) in Pkinase-Tyr to be statistically associated with KSHV. CONCLUSIONS Variations in the KSHV entry receptor gene EPHA2 affected susceptibility to KSHV infection and KS development in a South African HIV-infected patient cohort.
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Affiliation(s)
- Melissa J Blumenthal
- Division of Medical Biochemistry and Structural Biology, Department of Integrative Biomedical Sciences, University of Cape Town, South Africa; Institute of Infectious Disease and Molecular Medicine, University of Cape Town, South Africa
| | - Charlotte Schutz
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, South Africa; Wellcome Centre for Infectious Diseases Research in Africa, University of Cape Town, South Africa
| | - Graeme Meintjes
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, South Africa; Wellcome Centre for Infectious Diseases Research in Africa, University of Cape Town, South Africa
| | - Zainab Mohamed
- Division of Radiation Oncology, Department of Radiation Medicine, University of Cape Town, South Africa
| | - Marc Mendelson
- Division of Infectious Diseases & HIV Medicine, Department of Medicine, University of Cape Town, South Africa
| | - Jon M Ambler
- Computational Biology Group, Department of Integrative Biomedical Sciences, University of Cape Town, South Africa
| | - Denise Whitby
- Viral Oncology Section, AIDS and Cancer Virus Program, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, NIH, USA
| | | | - Sinead Carse
- Division of Medical Biochemistry and Structural Biology, Department of Integrative Biomedical Sciences, University of Cape Town, South Africa; Institute of Infectious Disease and Molecular Medicine, University of Cape Town, South Africa
| | - Arieh A Katz
- Division of Medical Biochemistry and Structural Biology, Department of Integrative Biomedical Sciences, University of Cape Town, South Africa; Institute of Infectious Disease and Molecular Medicine, University of Cape Town, South Africa
| | - Georgia Schäfer
- Division of Medical Biochemistry and Structural Biology, Department of Integrative Biomedical Sciences, University of Cape Town, South Africa; Institute of Infectious Disease and Molecular Medicine, University of Cape Town, South Africa.
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Zhou Y, Sakurai H. Emerging and Diverse Functions of the EphA2 Noncanonical Pathway in Cancer Progression. Biol Pharm Bull 2018; 40:1616-1624. [PMID: 28966234 DOI: 10.1248/bpb.b17-00446] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Erythropoietin-producing hepatocellular receptor A2 (EphA2) receptor tyrosine kinase controls multiple physiological processes to maintain homeostasis in normal cells. In many types of solid tumors, it has been reported that EphA2 is overexpressed and plays a critical role in oncogenic signaling. However, in recent years, the opposing functions of EphA2 have been explained by the canonical and noncanonical signaling pathways. Ligand- and tyrosine kinase-dependent EphA2 activation (the canonical pathway) inhibits cancer cell proliferation and motility. In contrast, ligand- and tyrosine kinase-independent EphA2 signaling (the noncanonical pathway) promotes tumor survival and metastasis and controls acquired drug resistance and maintenance of cancer stem cell-like properties. Evidence has accumulated showing that the EphA2 noncanonical pathway is mainly regulated by inflammatory cytokines and growth factors via phosphorylation at Ser-897 in the intracellular C-tail region via some serine/threonine kinases, including p90 ribosomal S6 kinase. In this review, we focus on the regulation of Ser-897 phosphorylation and its functional importance in tumor malignancy and discuss future therapeutic targeting.
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Affiliation(s)
- Yue Zhou
- Department of Cancer Cell Biology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama.,The MOE Key Laboratory for Standardization of Chinese Medicines and the Shanghai Key Laboratory of Compound Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine
| | - Hiroaki Sakurai
- Department of Cancer Cell Biology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama
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Liu Z, Tao Z, Zhang Q, Wan S, Zhang F, Zhang Y, Wu G, Wang J. YSA-conjugated mesoporous silica nanoparticles effectively target EphA2-overexpressing breast cancer cells. Cancer Chemother Pharmacol 2018; 81:687-695. [DOI: 10.1007/s00280-018-3535-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 01/29/2018] [Indexed: 02/06/2023]
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Tanabe S, Aoyagi K, Yokozaki H, Sasaki H. Molecular pathway network of EFNA1 in cancer and mesenchymal stem cells. ACTA ACUST UNITED AC 2018. [DOI: 10.3934/celltissue.2018.2.58] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Bennett TM, M’Hamdi O, Hejtmancik JF, Shiels A. Germ-line and somatic EPHA2 coding variants in lens aging and cataract. PLoS One 2017; 12:e0189881. [PMID: 29267365 PMCID: PMC5739433 DOI: 10.1371/journal.pone.0189881] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 12/04/2017] [Indexed: 11/18/2022] Open
Abstract
Rare germ-line mutations in the coding regions of the human EPHA2 gene (EPHA2) have been associated with inherited forms of pediatric cataract, whereas, frequent, non-coding, single nucleotide variants (SNVs) have been associated with age-related cataract. Here we sought to determine if germ-line EPHA2 coding SNVs were associated with age-related cataract in a case-control DNA panel (> 50 years) and if somatic EPHA2 coding SNVs were associated with lens aging and/or cataract in a post-mortem lens DNA panel (> 48 years). Micro-fluidic PCR amplification followed by targeted amplicon (exon) next-generation (deep) sequencing of EPHA2 (17-exons) afforded high read-depth coverage (1000x) for > 82% of reads in the cataract case-control panel (161 cases, 64 controls) and > 70% of reads in the post-mortem lens panel (35 clear lens pairs, 22 cataract lens pairs). Novel and reference (known) missense SNVs in EPHA2 that were predicted in silico to be functionally damaging were found in both cases and controls from the age-related cataract panel at variant allele frequencies (VAFs) consistent with germ-line transmission (VAF > 20%). Similarly, both novel and reference missense SNVs in EPHA2 were found in the post-mortem lens panel at VAFs consistent with a somatic origin (VAF > 3%). The majority of SNVs found in the cataract case-control panel and post-mortem lens panel were transitions and many occurred at di-pyrimidine sites that are susceptible to ultraviolet (UV) radiation induced mutation. These data suggest that novel germ-line (blood) and somatic (lens) coding SNVs in EPHA2 that are predicted to be functionally deleterious occur in adults over 50 years of age. However, both types of EPHA2 coding variants were present at comparable levels in individuals with or without age-related cataract making simple genotype-phenotype correlations inconclusive.
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Affiliation(s)
- Thomas M. Bennett
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Oussama M’Hamdi
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - J. Fielding Hejtmancik
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Alan Shiels
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri, United States of America
- * E-mail:
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Haghiralsadat F, Amoabediny G, Naderinezhad S, Nazmi K, De Boer JP, Zandieh-Doulabi B, Forouzanfar T, Helder MN. EphA2 Targeted Doxorubicin-Nanoliposomes for Osteosarcoma Treatment. Pharm Res 2017; 34:2891-2900. [DOI: 10.1007/s11095-017-2272-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 09/25/2017] [Indexed: 12/28/2022]
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Pearce AK, Fuchs AV, Fletcher NL, Thurecht KJ. Targeting Nanomedicines to Prostate Cancer: Evaluation of Specificity of Ligands to Two Different Receptors In Vivo. Pharm Res 2016; 33:2388-99. [DOI: 10.1007/s11095-016-1945-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 05/11/2016] [Indexed: 12/20/2022]
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Li HH, Kong LF, Yu R, Yu H, Li Q. Characterization, expression, and functional analysis of testis-specific serine/threonine kinase 1 (Tssk1) in the pen shellAtrina pectinata. INVERTEBR REPROD DEV 2016. [DOI: 10.1080/07924259.2016.1161667] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Dave A, Martin S, Kumar R, Craig JE, Burdon KP, Sharma S. EPHA2 MUTATIONS CONTRIBUTE TO CONGENITAL CATARACT THROUGH DIVERSE MECHANISMS. Mol Vis 2016; 22:18-30. [PMID: 26900323 PMCID: PMC4734147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 01/12/2016] [Indexed: 10/29/2022] Open
Abstract
PURPOSE Congenital cataract is a leading cause of childhood blindness. Mutations in the EPHA2 gene are one of the causes of inherited congenital cataract. The EPHA2 gene encodes a membrane-bound tyrosine kinase receptor and is highly expressed in epithelial cells, including in the ocular lens. Signaling through the EPHA2 receptor plays a pivotal role in epithelial cell homeostasis. The aim of this study was to determine the effect of congenital cataract causing mutations in the EPHA2 gene on the encoded protein in epithelial cells. METHODS The effect of five disease-causing mutations, p.P584L (c.1751C>T), p.T940I (c.2819C>T), p.D942fsXC71 (c.2826-9G>A), p.A959T (c.2875G>A), and p.V972GfsX39 (c.2915_2916delTG), on localization of the protein was examined in two in vitro epithelial cell culture systems: Madin-Darby Canine Kidney (MDCK) and human colorectal adenocarcinoma (Caco-2) epithelial cells. Myc-tagged mutant constructs were generated by polymerase chain reaction (PCR)-based mutagenesis. The Myc-tagged wild-type construct was used as a control. The Myc-tagged wild-type and mutant proteins were ectopically expressed and detected by immunofluorescence labeling. RESULTS Two of the mutations, p.T940I and p.D942fsXC71, located within the cytoplasmic sterile-α-motif (SAM) domain of EPHA2, led to mis-localization of the protein to the perinuclear space and co-localization with the cis-golgi apparatus, indicating sub-organellar/cellular retention of the mutant proteins. The mutant proteins carrying the remaining three mutations, similar to the wild-type EPHA2, localized to the cell membrane. CONCLUSIONS Mis-localization of two of the mutant proteins in epithelial cells suggests that some disease-causing mutations in EPHA2 likely affect lens epithelial cell homeostasis and contribute to cataract. This study suggests that mutations in EPHA2 contribute to congenital cataract through diverse mechanisms.
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Affiliation(s)
- Alpana Dave
- Department of Ophthalmology, Flinders University, Bedford Park, South Australia, Australia
| | - Sarah Martin
- Department of Ophthalmology, Flinders University, Bedford Park, South Australia, Australia
| | - Raman Kumar
- Robinson Research Institute, The University of Adelaide, Australia,School of Medicine, The University of Adelaide, Australia
| | - Jamie E. Craig
- Department of Ophthalmology, Flinders University, Bedford Park, South Australia, Australia
| | - Kathryn P. Burdon
- Department of Ophthalmology, Flinders University, Bedford Park, South Australia, Australia
| | - Shiwani Sharma
- Department of Ophthalmology, Flinders University, Bedford Park, South Australia, Australia
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Zhu Y, Ran T, Chen X, Niu J, Zhao S, Lu T, Tang W. Synthesis and Biological Evaluation of 1-(2-Aminophenyl)-3-arylurea Derivatives as Potential EphA2 and HDAC Dual Inhibitors. Chem Pharm Bull (Tokyo) 2016; 64:1136-41. [DOI: 10.1248/cpb.c16-00154] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Yong Zhu
- Department of Organic Chemistry, China Pharmaceutical University
| | - Ting Ran
- Laboratory of Molecular Design and Drug Discovery, School of Sciences, China Pharmaceutical University
| | - Xin Chen
- Department of Organic Chemistry, China Pharmaceutical University
| | - Jiaqi Niu
- Department of Organic Chemistry, China Pharmaceutical University
| | - Shuang Zhao
- Department of Organic Chemistry, China Pharmaceutical University
| | - Tao Lu
- Department of Organic Chemistry, China Pharmaceutical University
- State Key Laboratory of Natural Medicines, China Pharmaceutical University
| | - Weifang Tang
- Department of Organic Chemistry, China Pharmaceutical University
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Syed N, Barbhuiya MA, Pinto SM, Nirujogi RS, Renuse S, Datta KK, Khan AA, Srikumar K, Prasad TSK, Kumar MV, Kumar RV, Chatterjee A, Pandey A, Gowda H. Phosphotyrosine profiling identifies ephrin receptor A2 as a potential therapeutic target in esophageal squamous-cell carcinoma. Proteomics 2015; 15:374-82. [PMID: 25366905 PMCID: PMC4309511 DOI: 10.1002/pmic.201400379] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 10/01/2014] [Accepted: 10/28/2014] [Indexed: 01/17/2023]
Abstract
Esophageal squamous‐cell carcinoma (ESCC) is one of the most common malignancies in Asia. Currently, surgical resection of early‐stage tumor is the best available treatment. However, most patients present late when surgery is not an option. Data suggest that chemotherapy regimens are inadequate for clinical management of advanced cancer. Targeted therapy has emerged as one of the most promising approaches to treat several malignancies. A prerequisite for developing targeted therapy is prior knowledge of proteins and pathways that drive proliferation in malignancies. We carried out phosphotyrosine profiling across four different ESCC cell lines and compared it to non‐neoplastic Het‐1A cell line to identify activated tyrosine kinase signaling pathways in ESCC. A total of 278 unique phosphopeptides were identified across these cell lines. This included several tyrosine kinases and their substrates that were hyperphosphorylated in ESCC. Ephrin receptor A2 (EPHA2), a receptor tyrosine kinase, was hyperphosphorylated in all the ESCC cell lines used in the study. EPHA2 is reported to be oncogenic in several cancers and is also known to promote metastasis. Immunohistochemistry‐based studies have revealed EPHA2 is overexpressed in nearly 50% of ESCC. We demonstrated EPHA2 as a potential therapeutic target in ESCC by carrying out siRNA‐based knockdown studies. Knockdown of EPHA2 in ESCC cell line TE8 resulted in significant decrease in cell proliferation and invasion, suggesting it is a promising therapeutic target in ESCC that warrants further evaluation.
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Affiliation(s)
- Nazia Syed
- Institute of Bioinformatics, International Technology Park, Bangalore, India; Department of Biochemistry and Molecular Biology, Pondicherry University, Puducherry, India
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Ozcan G, Ozpolat B, Coleman RL, Sood AK, Lopez-Berestein G. Preclinical and clinical development of siRNA-based therapeutics. Adv Drug Deliv Rev 2015; 87:108-19. [PMID: 25666164 DOI: 10.1016/j.addr.2015.01.007] [Citation(s) in RCA: 332] [Impact Index Per Article: 36.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Revised: 01/23/2015] [Accepted: 01/29/2015] [Indexed: 12/23/2022]
Abstract
The discovery of RNA interference, first in plants and Caenorhabditis elegans and later in mammalian cells, led to the emergence of a transformative view in biomedical research. Knowledge of the multiple actions of non-coding RNAs has truly allowed viewing DNA, RNA and proteins in novel ways. Small interfering RNAs (siRNAs) can be used as tools to study single gene function both in vitro and in vivo and are an attractive new class of therapeutics, especially against undruggable targets for the treatment of cancer and other diseases. Despite the potential of siRNAs in cancer therapy, many challenges remain, including rapid degradation, poor cellular uptake and off-target effects. Rational design strategies, selection algorithms, chemical modifications and nanocarriers offer significant opportunities to overcome these challenges. Here, we review the development of siRNAs as therapeutic agents from early design to clinical trial, with special emphasis on the development of EphA2-targeting siRNAs for ovarian cancer treatment.
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22
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Harada K, Negishi M, Katoh H. HGF-induced serine 897 phosphorylation of EphA2 regulates epithelial morphogenesis of MDCK cells in 3D culture. J Cell Sci 2015; 128:1912-21. [PMID: 25908849 DOI: 10.1242/jcs.163790] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 03/20/2015] [Indexed: 02/02/2023] Open
Abstract
Expression of EphA2 is upregulated in various cancers that are derived from epithelial cells and correlates with the ability of a cancer cell to undergo migration and invasion. Here we have investigated the role of EphA2 in the epithelial morphogenesis of Madin-Darby canine kidney (MDCK) cells in three-dimensional culture. We show that EphA2 is phosphorylated on serine residue 897 through hepatocyte growth factor (HGF) stimulation using a phosphatidylinositol 3-kinase (PI3K)-Akt-dependent mechanism and that this phosphorylation is required for the formation of extensions, the first step of tubulogenesis, in MDCK cysts. By contrast, stimulation using the ligand ephrinA1 dephosphorylates EphA2 on serine residue 897 and suppresses the HGF-induced morphological change. Furthermore, activation of the small GTPase RhoG is involved in the HGF-induced formation of extensions downstream of EphA2. These observations suggest that a ligand-independent activity of EphA2 contributes to epithelial morphogenesis.
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Affiliation(s)
- Kohei Harada
- Laboratory of Molecular Neurobiology, Graduate School of Biostudies, Kyoto University, Yoshidakonoe-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Manabu Negishi
- Laboratory of Molecular Neurobiology, Graduate School of Biostudies, Kyoto University, Yoshidakonoe-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Hironori Katoh
- Laboratory of Molecular Neurobiology, Graduate School of Biostudies, Kyoto University, Yoshidakonoe-cho, Sakyo-ku, Kyoto 606-8501, Japan
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Gucciardo E, Sugiyama N, Lehti K. Eph- and ephrin-dependent mechanisms in tumor and stem cell dynamics. Cell Mol Life Sci 2014; 71:3685-710. [PMID: 24794629 PMCID: PMC11113620 DOI: 10.1007/s00018-014-1633-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Revised: 03/31/2014] [Accepted: 04/17/2014] [Indexed: 01/17/2023]
Abstract
The erythropoietin-producing hepatocellular (Eph) receptors comprise the largest family of receptor tyrosine kinases (RTKs). Initially regarded as axon-guidance and tissue-patterning molecules, Eph receptors have now been attributed with various functions during development, tissue homeostasis, and disease pathogenesis. Their ligands, ephrins, are synthesized as membrane-associated molecules. At least two properties make this signaling system unique: (1) the signal can be simultaneously transduced in the receptor- and the ligand-expressing cell, (2) the signaling outcome through the same molecules can be opposite depending on cellular context. Moreover, shedding of Eph and ephrin ectodomains as well as ligand-dependent and -independent receptor crosstalk with other RTKs, proteases, and adhesion molecules broadens the repertoire of Eph/ephrin functions. These integrated pathways provide plasticity to cell-microenvironment communication in varying tissue contexts. The complex molecular networks and dynamic cellular outcomes connected to the Eph/ephrin signaling in tumor-host communication and stem cell niche are the main focus of this review.
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Affiliation(s)
- Erika Gucciardo
- Research Programs Unit, Genome-Scale Biology, Biomedicum Helsinki, University of Helsinki, P.O.B. 63, 00014 Helsinki, Finland
| | - Nami Sugiyama
- Research Programs Unit, Genome-Scale Biology, Biomedicum Helsinki, University of Helsinki, P.O.B. 63, 00014 Helsinki, Finland
- Department of Biosystems Science and Bioengineering, ETH Zurich, Mattenstrasse 26, 4058 Basel, Switzerland
| | - Kaisa Lehti
- Research Programs Unit, Genome-Scale Biology, Biomedicum Helsinki, University of Helsinki, P.O.B. 63, 00014 Helsinki, Finland
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Lim CJ, Oh KS, Ha JD, Lee JH, Seo HW, Chae CH, Kim DG, Lee MJ, Lee BH. 4-Substituted quinazoline derivatives as novel EphA2 receptor tyrosine kinase inhibitors. Bioorg Med Chem Lett 2014; 24:4080-3. [DOI: 10.1016/j.bmcl.2014.07.081] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Revised: 07/09/2014] [Accepted: 07/29/2014] [Indexed: 11/29/2022]
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Xu J, Zhang J, Cui L, Zhang H, Zhang S, Bai Y. High EphA2 protein expression in renal cell carcinoma is associated with a poor disease outcome. Oncol Lett 2014; 8:687-692. [PMID: 25013485 PMCID: PMC4081399 DOI: 10.3892/ol.2014.2196] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2013] [Accepted: 05/07/2014] [Indexed: 12/19/2022] Open
Abstract
The receptor tyrosine kinase, ephrin type-A receptor 2 (EphA2), is normally expressed at sites of cell-to-cell contact in adult epithelial tissues, however, recent studies have shown that it is also overexpressed in various types of epithelial carcinomas, with the greatest level of EphA2 expression observed in metastatic lesions. In the present study, the association between the expression of EphA2 and the outcome of RCC patients was assessed. The high expression level of EphA2 was identified by log-rank test for a statistically significant prediction of the RCC outcome. In an overall multivariate analysis, the high expression level of EphA2 was identified as an independent predictor of RCC outcome. The length of survival of the patients with high EphA2 expression was shorter than that of the patients with a low level of expression (relative risk, 2.304; 95% CI, 1.102–4.818; P=0.027). The analysis of the expression levels of EphA2 in tumor tissues may aid in the identification of the patient subgroup that are at a high risk of a poor disease outcome.
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Affiliation(s)
- Jinsheng Xu
- Department of Nephrology, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China
| | - Junxia Zhang
- Department of Nephrology, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China
| | - Liwen Cui
- Department of Nephrology, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China
| | - Huiran Zhang
- Department of Nephrology, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China
| | - Shenglei Zhang
- Department of Nephrology, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China
| | - Yaling Bai
- Department of Nephrology, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China
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Hu F, Tao Z, Shen Z, Wang X, Hua F. Down-regulation of EphB4 phosphorylation is necessary for esophageal squamous cell carcinoma tumorigenecity. Tumour Biol 2014; 35:7225-32. [PMID: 24771266 DOI: 10.1007/s13277-014-1955-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Accepted: 04/07/2014] [Indexed: 02/05/2023] Open
Abstract
Eph/ephrin signaling system plays a very important role in the tumorigenesis and the formation of blood vessel. However, the function of EphB4 and its ligand ephrin B2 in the carcinogenesis of esophageal squamous cell carcinoma (ESCC) is not fully understood. Here, it was found that the expression of EphB4 was up-regulated in ESCC tissues compared with the paired normal tissues, while ephrin B2 was down-regulated in ESCC samples. Phosphorylation of EphB4 induced by its ligand ephrin B2-Fc inhibited the growth, migration and colony formation of ESCC cells. Moreover, over-expression of EphB4 or EphB4 kinase dead mutant (EphB4 KD) in ESCC cells promoted cell growth and migration, suggesting EphB4 promoted cell growth and migration independent of its kinase activity. Furthermore, we found that EphB4 interacted with the adaptor protein RACK1 and RACK1 decreased the phosphorylation level of EphB4. Taken together, our study revealed the important function and regulation of EphB4 in the progression of ESCC and suggested EphB4 as a novel target for the treatment of ESCC.
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Affiliation(s)
- Fengqing Hu
- Department of Cardiovascular Surgery, First Affiliated Hospital of Soochow University, 188 Shizijie, Suzhou, 215000, China
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27
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Chen P, Huang Y, Zhang B, Wang Q, Bai P. EphA2 enhances the proliferation and invasion ability of LNCaP prostate cancer cells. Oncol Lett 2014; 8:41-46. [PMID: 24959216 PMCID: PMC4063646 DOI: 10.3892/ol.2014.2093] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2013] [Accepted: 04/01/2014] [Indexed: 12/30/2022] Open
Abstract
EphA2 is persistently overexpressed and functionally changed in numerous human cancers. However, to the best of our knowledge, the role that EphA2 plays in prostate cancer is not entirely clear. To investigate the roles of EphA2 in the development and progression of prostate cancer, the present study initially evaluated the roles of the EphA2 protein in LNCaP prostate cancer cells using recombinant plasmid, western blot analysis, flow cytometry, Matrigel invasion chamber and the cell counting kit-8 assay. An immunohistochemistry assay was also conducted to observe the effects of EphA2 in prostate cancer tissues. The results demonstrated that the LNCaP human prostate cancer cells that were transfected with pcDNA3.1(+) plasmid-mediated pcDNA3.1(+)-EphA2, markedly enhanced the cell growth and invasion in vitro. Additionally, EphA2 was overexpressed in prostate cancer specimens and the expression of EphA2 was significantly associated with Gleason grade, total prostate-specific antigen, advanced clinical stage and lymph node metastasis. Collectively, these results demonstrate that EphA2 is involved in malignant cell behavior and is a potential therapeutic target in human prostate cancer.
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Affiliation(s)
- Peijie Chen
- Department of Urology, Zhongshan Hospital, Xiamen University, Xiamen, Fujian 361004, P.R. China
| | - Yan Huang
- Department of Urology, Zhongshan Hospital, Xiamen University, Xiamen, Fujian 361004, P.R. China
| | - Bo Zhang
- Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, P.R. China
| | - Qiuquan Wang
- Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, P.R. China
| | - Peiming Bai
- Department of Urology, Zhongshan Hospital, Xiamen University, Xiamen, Fujian 361004, P.R. China
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Yang J, Luo J, Zhou P, Fan Q, Luo Y, Lu Y. Association of the ephreceptor tyrosinekinase-type A2 (EPHA2) gene polymorphism rs3754334 with age-related cataract risk: a meta-analysis. PLoS One 2013; 8:e71003. [PMID: 23976972 PMCID: PMC3745390 DOI: 10.1371/journal.pone.0071003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Accepted: 07/01/2013] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Recent clinical studies have assessed the association of various polymorphisms on the ephreceptor tyrosinekinase-type A2 (EPHA2) with the risk for age-related cataract in populations of different ethnic/racial backgrounds, but inconsistent results have been obtained. OBJECTIVE This meta-analysis aimed to identify if any polymorphism(s) might be commonly present in different ethnic/racial populations in association with the age-related cataract risk. METHODS The PubMed and Web of Science databases (up to December 1, 2012) were searched for clinical studies on the association of EPHA2 polymorphisms with the risk for age-related cataract. The polymorphisms that were assessed in all eligible studies were analyzed for their association with the risk for age-related cataract using different models. RESULTS Three studies were identified, which were conducted, respectively, on white Americans in the Unites States and on Asians in Indian and China. The polymorphism, rs3754334, was the only one studied in all these three studies and was therefore the focus of this meta-analysis. No publication bias or heterogeneity was found. Our analysis results demonstrated that rs3754334 was associated with the risk of any cataracts in the recessive (OR = 1.202, 95% CI: 1.051-1.375, P = 0.007) and Codominant (OR = 1.194, 95% CI: 1.035-1.378, P = 0.015) models, but its association with cortical or nuclear phenotype of age-related cataract was not evident. CONCLUSION Polymorphism, rs3754334, might be a variant on the EPHA2 gene that is commonly associated with the risk for age-related cataract in different ethnical and geographical populations.
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Affiliation(s)
- Jin Yang
- Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China
| | - Jianfeng Luo
- Department of Health Statistics and Social Medicine, School of Public Health, Fudan University, Shanghai, China
| | - Peng Zhou
- Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China
| | - Qi Fan
- Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China
| | - Yi Luo
- Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China
| | - Yi Lu
- Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China
- * E-mail:
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Park JE, Son AI, Zhou R. Roles of EphA2 in Development and Disease. Genes (Basel) 2013; 4:334-57. [PMID: 24705208 PMCID: PMC3924825 DOI: 10.3390/genes4030334] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 05/22/2013] [Accepted: 05/23/2013] [Indexed: 01/12/2023] Open
Abstract
The Eph family of receptor tyrosine kinases (RTKs) has been implicated in the regulation of many aspects of mammalian development. Recent analyses have revealed that the EphA2 receptor is a key modulator for a wide variety of cellular functions. This review focuses on the roles of EphA2 in both development and disease.
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Affiliation(s)
- Jeong Eun Park
- Susan Lehman-Cullman Laboratory for Cancer Research, Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ 08854, USA.
| | - Alexander I Son
- Susan Lehman-Cullman Laboratory for Cancer Research, Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ 08854, USA.
| | - Renping Zhou
- Susan Lehman-Cullman Laboratory for Cancer Research, Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ 08854, USA.
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Cui XD, Lee MJ, Kim JH, Hao PP, Liu L, Yu GR, Kim DG. Activation of mammalian target of rapamycin complex 1 (mTORC1) and Raf/Pyk2 by growth factor-mediated Eph receptor 2 (EphA2) is required for cholangiocarcinoma growth and metastasis. Hepatology 2013; 57:2248-60. [PMID: 23315987 DOI: 10.1002/hep.26253] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Accepted: 12/13/2012] [Indexed: 12/28/2022]
Abstract
Eph receptor 2 (EphA2) overexpression is frequently accompanied by the loss of its cognate ligand during tumor progression. However, the molecular mechanism of this ligand-independent promotion of tumor by EphA2 remains unclear in highly malignant and fatal cholangiocarcinoma (CC). We examined the biological role of EphA2 in tumor growth and metastasis in CC tissues and cells according to the degree of differentiation and we explored the downstream signaling pathways of EphA2. Growth factor-mediated EphA2 overexpression itself leads to the activation of the mammalian target of rapamycin complex 1 (mTORC1) and extracellular signal-regulated kinase (ERK) pathways through ligand-independent activation of EphA2 (phosphorylation of S897). An in vitro soft agar assay and in vivo orthotopic or subcutaneous tumor model showed that EphA2 enhanced colony formation and accelerated tumor growth, and which seemed to be mainly associated with Akt (T308)/mTORC1 activation. Aberrant expression and activation of EphA2 was also associated with poorer differentiation and higher metastatic ability. Enhanced metastatic ability was also observed in an orthotopic tumor model or lung metastasis model, correlating with Pyk2(Y402)/c-Src/ERK activation in addition to activation of the canonical Raf/MEK/ERK pathway. The mTORC1 and Raf/Pyk2 pathways also appeared to affect each other. These results suggest that growth factor-mediated EphA2 might be involved in tumor growth and metastasis through activation of the mTORC1 and Raf/Pyk2 pathways. Therapeutic strategies that target EphA2 and its downstream effectors may be useful to control CC. (HEPATOLOGY 2013;57:2248-2260).
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Affiliation(s)
- Xiang-Dan Cui
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Institute for Medical Science, Chonbuk National University Medical School and Hospital, Jeonju, Jeonbuk, Republic of Korea
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Tandon M, Vemula SV, Sharma A, Ahi YS, Mittal S, Bangari DS, Mittal SK. EphrinA1-EphA2 interaction-mediated apoptosis and FMS-like tyrosine kinase 3 receptor ligand-induced immunotherapy inhibit tumor growth in a breast cancer mouse model. J Gene Med 2012; 14:77-89. [PMID: 22228563 DOI: 10.1002/jgm.1649] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND The receptor tyrosine kinase EphA2 is overexpressed in several types of cancers and is currently being pursued as a target for breast cancer therapeutics. The EphA2 ligand EphrinA1 induces EphA2 phosphorylation and intracellular internalization and degradation, thus inhibiting tumor progression. The hematopoietic growth factor, FMS-like tyrosine kinase 3 receptor ligand (Flt3L), promotes expansion and mobilization of functional dendritic cells. METHODS We tested the EphrinA1-EphA2 interaction in MDA-MB-231 breast cancer cells focusing on the receptor-ligand-mediated apoptosis of breast cancer cells. To determine whether EphrinA1-EphA2 interaction-associated apoptosis and Flt3L-mediated immunotherapy would have an additive effect in inhibiting tumor growth, we used an immunocompetent mouse model of breast cancer to evaluate intratumoral (i.t.) inoculation strategies with human adenovirus (HAd) vectors expressing either EphrinA1 (HAd-EphrinA1-Fc), Flt3L (HAd-Flt3L) or a combination of EphrinA1-Fc + Flt3L (HAd-EphrinA1-Fc + HAd-Flt3L). RESULTS In vitro analysis demonstrated that an EphrinA1-EphA2 interaction led to apoptosis-related changes in breast cancer cells. In vivo, three i.t. inoculations of HAd-EphrinA1-Fc showed potent inhibition of tumor growth. Furthermore, increased inhibition in tumor growth was observed with the combination of HAd-EphrinA1-Fc and HAd-Flt3L accompanied by the generation of an anti-tumor adaptive immune response. CONCLUSIONS The results obtained in the present study, indicating the induction of apoptosis and inhibition of mammary tumor growth, show the potential therapeutic benefits of HAd-EphrinA1-Fc. In combination with HAd-Flt3L, this represents a promising strategy for effectively inducing mammary tumor regression by HAd vector-based therapy.
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Affiliation(s)
- Manish Tandon
- Department of Comparative Pathobiology, Purdue University Center for Cancer Research, and Bindley Bioscience Center, Purdue University, West Lafayette, IN 47907, USA
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Repertoire of Protein Kinases Encoded in the Genome of Takifugu rubripes. Comp Funct Genomics 2012; 2012:258284. [PMID: 22666085 PMCID: PMC3359783 DOI: 10.1155/2012/258284] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2011] [Revised: 02/14/2012] [Accepted: 02/28/2012] [Indexed: 12/02/2022] Open
Abstract
Takifugu rubripes is teleost fish widely used in comparative genomics to understand the human system better due to its similarities both in number of genes and structure of genes. In this work we survey the fugu genome, and, using sensitive computational approaches, we identify the repertoire of putative protein kinases and classify them into groups and subfamilies. The fugu genome encodes 519 protein kinase-like sequences and this number of putative protein kinases is comparable closely to that of human. However, in spite of its similarities to human kinases at the group level, there are differences at the subfamily level as noted in the case of KIS and DYRK subfamilies which contribute to differences which are specific to the adaptation of the organism. Also, certain unique domain combination of galectin domain and YkA domain suggests alternate mechanisms for immune response and binding to lipoproteins. Lastly, an overall similarity with the MAPK pathway of humans suggests its importance to understand signaling mechanisms in humans. Overall the fugu serves as a good model organism to understand roles of human kinases as far as kinases such as LRRK and IRAK and their associated pathways are concerned.
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Annunziata CM, Kohn EC, LoRusso P, Houston ND, Coleman RL, Buzoianu M, Robbie G, Lechleider R. Phase 1, open-label study of MEDI-547 in patients with relapsed or refractory solid tumors. Invest New Drugs 2012; 31:77-84. [PMID: 22370972 PMCID: PMC3553417 DOI: 10.1007/s10637-012-9801-2] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Accepted: 02/09/2012] [Indexed: 11/25/2022]
Abstract
Background Targeting the cell-surface receptor EphA2, which is highly expressed in some solid tumors, is a novel approach for cancer therapy. We aimed to evaluate the safety profile, maximum tolerated dose (MTD), pharmacokinetics, and antitumor activity of MEDI-547, an antibody drug conjugate composed of the cytotoxic drug auristatin (toxin) linked to a human anti-EphA2 monoclonal antibody (1C1), in patients with solid tumors relapsed/refractory to standard therapy. Methods In this phase 1, open-label study with planned dose-escalation and dose-expansion cohorts, patients received a 1-h intravenous infusion of MEDI-547 (0.08 mg/kg) every 3 weeks. Results Six patients received 0.08 mg/kg; all discontinued treatment. Dose escalation was not pursued. The study was stopped before cohort 2 enrollment due to treatment-related bleeding and coagulation events (hemorrhage-related, n = 3; epistaxis, n = 2). Therefore, lower doses were not explored and an MTD could not be selected. The most frequently reported treatment-related adverse events (AEs) were increased liver enzymes, decreased hemoglobin, decreased appetite, and epistaxis. Three patients (50%) experienced treatment-related serious AEs, including conjunctival hemorrhage, pain (led to study drug discontinuation), liver disorder, and hemorrhage. Best response included progressive disease (n = 5; 83.3%) and stable disease (n = 1; 16.7%). Minimal or no dissociation of toxin from 1C1 conjugate occurred in the blood. Serum MEDI-547 concentrations decreased rapidly, ~70% by 3 days post-dose. No accumulation of MEDI-547 was observed at 0.08 mg/kg upon administration of a second dose 3 weeks following dose 1. Conclusions The safety profile of MEDI-547 does not support further clinical investigation in patients with advanced solid tumors.
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Affiliation(s)
- Christina M Annunziata
- Medical Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, 10 Center Drive, Room 12 N226, Bethesda, MD 20892-1906, USA.
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Ishikawa M, Miyahara R, Sonobe M, Horiuchi M, Mennju T, Nakayama E, Kobayashi M, Kikuchi R, Kitamura J, Imamura N, Huang CL, Date H. Higher expression of EphA2 and ephrin-A1 is related to favorable clinicopathological features in pathological stage I non-small cell lung carcinoma. Lung Cancer 2012; 76:431-8. [PMID: 22236865 DOI: 10.1016/j.lungcan.2011.12.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Revised: 11/21/2011] [Accepted: 12/05/2011] [Indexed: 11/25/2022]
Abstract
BACKGROUND The overexpression of receptor tyrosine kinase EphA2 has been reported in various cancers. In non-small cell lung cancer (NSCLC), a positive correlation has been reported between high EphA2 immunohistochemical staining level and poor prognosis. However, its ligand, ephrin-A1, is supposed to act as a tumor suppressor via the kinase activity of EphA2. Thus, the biphasic roles of this system are not fully elucidated. We retrospectively evaluated the expression levels of EphA2 and ephrin-A1 in surgically treated pathological (p-) stage I NSCLC tumor samples, and their relation to clinicopathologic features or postoperative prognoses. METHODS The levels of EphA2 and ephrin-A1 mRNA expression were quantified by real-time reverse-transcription polymerase chain reaction in tissue samples from p-stage I NSCLC patients who had undergone complete resection in our facility (n=195). They were divided into two (EphA2/ephrin-A1-Low and -High) groups based on the median expression level, and their respective clinicopathologic features and prognoses were analyzed. Furthermore, samples were stained immunohistochemically and classified into four groups according to their staining levels, and their prognoses analyzed. RESULTS Marked demographic differences were found between EphA2/ephrin-A1-Low and -High groups. Both EphA2-High and ephrin-A1-High groups had more females, no smoking history, adenocarcinoma histology, well-differentiated carcinomas, p-stage IA patients, and patients with EGFR gene mutations. Five-year overall survival rates of the EphA2-Low and the EphA2-High patient groups were 68.9% and 86.1%, respectively (P=0.017), and five-year disease-free survival rates were 69.9% and 83.2%, respectively (P=0.035). There were no statistical differences between ephrin-A1-Low and ephrin-A1-High groups concerning postoperative survival. Although showing smaller differences, the findings from the immunohistochemical analyses supported the above results. CONCLUSIONS Higher expression of EphA2 and ephrin-A1 was more related to the female sex, reduced smoking status, adenocarcinoma, well differentiated carcinomas, p-stage IA, and EGFR gene mutations. Higher EphA2 mRNA expression in p-stage I NSCLC patients was positively related to improved prognoses. These results may reflect a tumor suppressive role for the EphA2/ephrin-A1 system in a population of patients restricted to p-stage I NSCLC.
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Affiliation(s)
- Masashi Ishikawa
- Faculty of Medicine, Department of Thoracic Surgery, Kyoto University, 54 Shogoin-kawaharacho, Sakyo-ku, Kyoto, 606-8507, Japan
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Ephs and ephrins in cancer: ephrin-A1 signalling. Semin Cell Dev Biol 2011; 23:109-15. [PMID: 22040911 DOI: 10.1016/j.semcdb.2011.10.019] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Accepted: 10/17/2011] [Indexed: 11/21/2022]
Abstract
Ephrin-A1 and its primary receptor, EphA2, are involved in numerous physiological processes and have been intensely studied for their roles in malignancy. Ephrin-Eph signalling is complex on its own and is also cell-type dependent, making elucidation of the exact role of ephrin-A1 in neoplasia challenging. Multiple oncogenic signalling pathways, such as MAP/ERK and PI3K are affected by ephrin-A1, and in some cases evidence suggests the promotion of a specific pathway in one cell or cancer type and inhibition of the same pathway in another type of cell or cancer. Ephrin-A1 also plays an integral role in angiogenesis and tumor neovascularization. Until recently, studies investigating ephrins focused on the ligands as GPI-anchored proteins that required membrane anchoring or artificial clustering for Eph receptor activation. However, recent studies have demonstrated a functional role for soluble, monomeric ephrin-A1. This review will focus on various forms of ephrin-A1-specific signalling in human malignancy.
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Activation of erythropoietin-producing hepatocellular receptor A2 attenuates cell adhesion of human fallopian tube epithelial cells via focal adhesion kinase dephosphorylation. Mol Cell Biochem 2011; 361:259-65. [DOI: 10.1007/s11010-011-1111-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2011] [Accepted: 10/07/2011] [Indexed: 10/16/2022]
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Tandon M, Vemula SV, Mittal SK. Emerging strategies for EphA2 receptor targeting for cancer therapeutics. Expert Opin Ther Targets 2011; 15:31-51. [PMID: 21142802 DOI: 10.1517/14728222.2011.538682] [Citation(s) in RCA: 195] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
IMPORTANCE OF THE FIELD High mortality rates with cancers warrant further development of earlier diagnostics and better treatment strategies. Membrane-bound erythropoietin-producing hepatocellular receptor tyrosine kinase class A2 (EphA2) is overexpressed in breast, prostate, urinary bladder, skin, lung, ovary and brain cancers. AREAS COVERED IN THIS REVIEW EphA2 overexpression in cancers, its signaling mechanisms and strategies to target its deregulation. WHAT THE READER WILL GAIN High EphA2 expression in cancer cells is correlated with a poor prognosis associated with recurrence due to enhanced metastasis. Interaction of the EphA2 receptor with its ligand (e.g., ephrinA1) triggers events that are deregulated and implicated in carcinogenesis. EphrinA1-independent oncogenic activity and ephrinA1-dependent tumor suppressor roles for EphA2 are described. Molecular interactions of EphA2 with signaling proteins are associated with the modulation of cytoskeleton dynamics, cell adhesion, proliferation, differentiation and metastasis. The deregulated signaling by EphA2 and its involvement in oncogenesis provide multiple avenues for the rational design of intervention approaches. TAKE HOME MESSAGE EphA2 has been tested as a drug target using multiple approaches such as agonist antibodies, RNA interference, immunotherapy, virus vector-mediated gene transfer, small-molecule inhibitors and nanoparticles. With over a decade of research, encouraging results with targeting of EphA2 expression in various pre-clinical cancer models necessitate further studies.
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Affiliation(s)
- Manish Tandon
- Purdue University, Department of Comparative Pathobiology, Bindley Bioscience Center, West Lafayette, IN 47907, USA
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Lin S, Gordon K, Kaplan N, Getsios S. Ligand targeting of EphA2 enhances keratinocyte adhesion and differentiation via desmoglein 1. Mol Biol Cell 2010; 21:3902-14. [PMID: 20861311 PMCID: PMC2982116 DOI: 10.1091/mbc.e10-03-0242] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Cell–cell adhesion and communication maintains epithelial tissue homeostasis. This study demonstrates that ephrin ligands target the EphA2 receptor to dampen Erk1/2 signaling without affecting cell proliferation and identifies a novel link with desmoglein 1, a desmosomal cadherin that enhances epidermal adhesion and differentiation. EphA2 is a receptor tyrosine kinase that is engaged and activated by membrane-linked ephrin-A ligands residing on adjacent cell surfaces. Ligand targeting of EphA2 has been implicated in epithelial growth regulation by inhibiting the extracellular signal-regulated kinase 1/2 (Erk1/2)-mitogen activated protein kinase (MAPK) pathway. Although contact-dependent EphA2 activation was required for dampening Erk1/2-MAPK signaling after a calcium switch in primary human epidermal keratinocytes, the loss of this receptor did not prevent exit from the cell cycle. Incubating keratinocytes with a soluble ephrin-A1-Fc peptide mimetic to target EphA2 further increased receptor activation leading to its down-regulation. Moreover, soluble ligand targeting of EphA2 restricted the lateral expansion of epidermal cell colonies without limiting proliferation in these primary cultures. Rather, ephrin-A1-Fc peptide treatment promoted epidermal cell colony compaction and stratification in a manner that was associated with increased keratinocyte differentiation. The ligand-dependent increase in keratinocyte adhesion and differentiation relied largely upon the up-regulation of desmoglein 1, a desmosomal cadherin that maintains the integrity and differentiated state of suprabasal keratinocytes in the epidermis. These data suggest that keratinocytes expressing EphA2 in the basal layer may respond to ephrin-A1–based cues from their neighbors to facilitate entry into a terminal differentiation pathway.
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Affiliation(s)
- Samantha Lin
- Department of Dermatology and Cell and Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
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Stroylov VS, Rakitina TV, Novikov FN, Stroganov OV, Chilova GG, Lipkin AV. Novel fragment-like inhibitors of EphA2 obtained by experimental screening and modelling. MENDELEEV COMMUNICATIONS 2010. [DOI: 10.1016/j.mencom.2010.09.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Gökmen-Polar Y, Toroni RA, Hocevar BA, Badve S, Zhao Q, Shen C, Bruckheimer E, Kinch MS, Miller KD. Dual targeting of EphA2 and ER restores tamoxifen sensitivity in ER/EphA2-positive breast cancer. Breast Cancer Res Treat 2010; 127:375-84. [PMID: 20602165 DOI: 10.1007/s10549-010-1004-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2010] [Accepted: 06/17/2010] [Indexed: 01/11/2023]
Abstract
Overexpression and altered function of EphA2 receptor tyrosine kinase are critical in the progression of breast cancer and provide a target for breast cancer therapy. We have previously demonstrated that EphA2 overexpression decreases estrogen dependence and Tamoxifen sensitivity both in vitro and in vivo. EA5, a novel monoclonal antibody that mimicks the binding of ephrin A to EphA2, reverses the effect of EphA2 overexpression and restores Tamoxifen sensitivity in EphA2-transfected MCF-7 cells in vitro. To explore the role of EphA2 overexpression on ER-dependent mechanisms, we used two different ER+/EphA2-transfected cell line models (MCF-7(neo)/MCF-7(EphA2) and T47D(neo)/T47D(EphA2)). EA5 inhibits primary tumor growth and restores Tamoxifen sensitivity in the MCF-7(EphA2) xenografts. Using the T47D(EphA2) in vitro model, we verified that EphA2 decreases ER activation in response to E2 stimulation consistent with our earlier results in MCF-7(EphA2) model. We found no direct interaction between ER and EphA2 and no difference in expression of canonical ER-dependent proteins or ER co-regulators. However, E2 stimulation phosphorylates FAK(Tyr925) only in ER+/EphA2+ cell lines. Treatment of T47D(EphA2) cells with EA5 and Tamoxifen leads to dephosphorylation of FAK(Tyr925) in response to E2. Our data demonstrate that dual targeting of EphA2 and ER is a promising approach for delaying resistance to Tamoxifen. The data support our hypothesis that EphA2 impacts ER function via a FAK dependent pathway.
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Affiliation(s)
- Yesim Gökmen-Polar
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
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Up-regulation of EphA2 and down-regulation of EphrinA1 are associated with the aggressive phenotype and poor prognosis of malignant glioma. Tumour Biol 2010; 31:477-88. [PMID: 20571968 DOI: 10.1007/s13277-010-0060-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2010] [Accepted: 06/02/2010] [Indexed: 10/19/2022] Open
Abstract
Malignant gliomas display over-expression of the receptor tyrosine kinase EphA2. However, expression levels of the EphA2 ligand, EphrinA1, have not been fully elucidated. Seventy-eight patients with primary gliomas were included in this study who underwent surgical resection, radiation, and chemotherapy. The expression of EphA2 and EphrinA1 in tumors was assessed by immunohistochemistry and was statistically analyzed in combination with the follow-up data of patients. EphA2 was highly expressed in most malignant gliomas, but EphrinA1 was expressed at low levels in these tumors. The increased EphA2 expression is associated with higher-grade histology and poor patient prognosis. Contrary to this, the increased EphrinA1 expression is associated with lower-grade histology, but not associated with poor patient prognosis. Moreover, patients with tumors positive for EphA2 and negative for EphrinA1 had significantly shorter overall and progression-free survival than patients with tumors positive for both EphA2 and EphrinA1, negative for both EphA2 and EphrinA1, or negative for EphA2 and positive for EphrinA1. RNAi-mediated suppression of endogenous EphA2 in human glioblastoma multiforme cells resulted in increased EphrinA1 levels, as well as decreased cell viability, anchorage independence and in vitro invasion, and increased apoptosis. Furthermore, suppression of EphA2 resulted in delayed tumor growth in mice xenografts. Together, these data indicate that up-regulation of EphA2 and down-regulation of Ephrina1 may correlate with poor prognosis for patients with high-grade glioma. EphA2 suppression partially reversed the aggressive phenotypes of malignant gliomas, possibly through up-regulating EphrinA1 expression, which may help explain how EphA2 modulates the malignant progression of gliomas.
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An extracellular steric seeding mechanism for Eph-ephrin signaling platform assembly. Nat Struct Mol Biol 2010; 17:398-402. [PMID: 20228801 DOI: 10.1038/nsmb.1782] [Citation(s) in RCA: 160] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Accepted: 01/29/2010] [Indexed: 01/27/2023]
Abstract
Erythropoetin-producing hepatoma (Eph) receptors are cell-surface protein tyrosine kinases mediating cell-cell communication. Upon activation, they form signaling clusters. We report crystal structures of the full ectodomain of human EphA2 (eEphA2) both alone and in complex with the receptor-binding domain of the ligand ephrinA5 (ephrinA5 RBD). Unliganded eEphA2 forms linear arrays of staggered parallel receptors involving two patches of residues conserved across A-class Ephs. eEphA2-ephrinA5 RBD forms a more elaborate assembly, whose interfaces include the same conserved regions on eEphA2, but rearranged to accommodate ephrinA5 RBD. Cell-surface expression of mutant EphA2s showed that these interfaces are critical for localization at cell-cell contacts and activation-dependent degradation. Our results suggest a 'nucleation' mechanism whereby a limited number of ligand-receptor interactions 'seed' an arrangement of receptors which can propagate into extended signaling arrays.
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Cui XD, Lee MJ, Yu GR, Kim IH, Yu HC, Song EY, Kim DG. EFNA1 ligand and its receptor EphA2: potential biomarkers for hepatocellular carcinoma. Int J Cancer 2010; 126:940-9. [PMID: 19642143 DOI: 10.1002/ijc.24798] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Novel biomarkers are needed for early detection and progression evaluation of hepatocellular carcinoma (HCC). The purpose of this study was to identify useful biomolecular markers for HCC. The 26 genes that encode membrane or secretory proteins were identified from cDNA microarray data. We further examined the expression of EFNA1 and its receptor EphA2 and determined their biological implications during the development and progression of HCC. The EFNA1 mRNA was overexpressed in most HCCs as compared with its expression in corresponding nontumor tissues (36 out of 40 cases, 90%), but EphA2 expression was noted in only half of the HCC tissues (20 of 40 cases, 50%). In most of the hepatoma cell lines, the EFNA1 protein expression was positively associated with alpha-fetoprotien (AFP) expression but inversely associated with EphA2 expression. Furthermore, EFNA1 levels were detectable in the supernatant of the cultured hepatoma cells and in the serum of patients with HCC. In contrast, EphA2 expression was prominent in highly invasive hepatoma cells, and its overexpression was significantly correlated with decreased differentiation (r = 0.0248, p < 0.010) and poor survival (p = 0.0453) for HCC patients. EFNA1 and EphA2 may be useful serum markers for the detection of HCC development and progression, respectively.
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Affiliation(s)
- Xiang-Dan Cui
- Division of Gastroenterology and Hepatology, The Institute for Medical Science, Department of Internal Medicine, Chonbuk National University Medical School and Hospital, Jeonju, Jeonbuk, Republic of Korea
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Dickerson EB, Blackburn WH, Smith MH, Kapa LB, Lyon LA, McDonald JF. Chemosensitization of cancer cells by siRNA using targeted nanogel delivery. BMC Cancer 2010; 10:10. [PMID: 20064265 PMCID: PMC2820460 DOI: 10.1186/1471-2407-10-10] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2009] [Accepted: 01/11/2010] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Chemoresistance is a major obstacle in cancer treatment. Targeted therapies that enhance cancer cell sensitivity to chemotherapeutic agents have the potential to increase drug efficacy while reducing toxic effects on untargeted cells. Targeted cancer therapy by RNA interference (RNAi) is a relatively new approach that can be used to reversibly silence genes in vivo by selectively targeting genes such as the epidermal growth factor receptor (EGFR), which has been shown to increase the sensitivity of cancer cells to taxane chemotherapy. However, delivery represents the main hurdle for the broad development of RNAi therapeutics. METHODS We report here the use of core/shell hydrogel nanoparticles (nanogels) functionalized with peptides that specially target the EphA2 receptor to deliver small interfering RNAs (siRNAs) targeting EGFR. Expression of EGFR was determined by immunoblotting, and the effect of decreased EGFR expression on chemosensitization of ovarian cancer cells after siRNA delivery was investigated. RESULTS Treatment of EphA2 positive Hey cells with siRNA-loaded, peptide-targeted nanogels decreased EGFR expression levels and significantly increased the sensitivity of this cell line to docetaxel (P < 0.05). Nanogel treatment of SK-OV-3 cells, which are negative for EphA2 expression, failed to reduce EGFR levels and did not increase docetaxel sensitivity (P > 0.05). CONCLUSION This study suggests that targeted delivery of siRNAs by nanogels may be a promising strategy to increase the efficacy of chemotherapy drugs for the treatment of ovarian cancer. In addition, EphA2 is a viable target for therapeutic delivery, and the siRNAs are effectively protected by the nanogel carrier, overcoming the poor stability and uptake that has hindered clinical advancement of therapeutic siRNAs.
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Affiliation(s)
- Erin B Dickerson
- School of Biology, Georgia Institute of Technology, 310 Ferst Drive, Atlanta, GA 30332, USA
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Lee JW, Han HD, Shahzad MMK, Kim SW, Mangala LS, Nick AM, Lu C, Langley RR, Schmandt R, Kim HS, Mao S, Gooya J, Fazenbaker C, Jackson D, Tice DA, Landen CN, Coleman RL, Sood AK. EphA2 immunoconjugate as molecularly targeted chemotherapy for ovarian carcinoma. J Natl Cancer Inst 2009; 101:1193-205. [PMID: 19641174 DOI: 10.1093/jnci/djp231] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND EphA2 is overexpressed in many types of human cancer but is absent or expressed at low levels in normal epithelial tissues. We investigated whether a novel immunoconjugate containing an anti-EphA2 monoclonal antibody (1C1) linked to a chemotherapeutic agent (monomethyl auristatin phenylalanine [MMAF]) through a noncleavable linker maleimidocaproyl (mc) had antitumor activity against ovarian cancer cell lines and tumor models. METHODS Specificity of 1C1-mcMMAF was examined in EphA2-positive HeyA8 and EphA2-negative SKMel28 ovarian cancer cells by antibody binding and internalization assays. Controls were phosphate-buffered saline (PBS), 1C1, or control IgG-mcMMAF. Viability and apoptosis were investigated in ovarian cancer cell lines and tumor models (10 mice per group). Antitumor activities were tested in the HeyA8-luc and SKOV3ip1 orthotopic mouse models of ovarian cancer. Endothelial cells were identified by use of immunohistochemistry and anti-CD31 antibodies. All statistical tests were two-sided. RESULTS The 1C1-mcMMAF immunoconjugate specifically bound to EphA2-positive HeyA8 cells but not to EphA2-negative cells and was internalized by HeyA8 cells. Treatment with 1C1-mcMMAF decreased the viability of HeyA8-luc cells in an EphA2-specific manner. In orthotopic mouse models, treatment with 1C1-mcMMAF inhibited tumor growth by 85%-98% compared with that in control mice (eg, for weight of HeyA8 tumors, 1C1-mcMMAF = 0.05 g and control = 1.03 g; difference = 0.98 g, 95% confidence interval [CI] = 0.40 to 1.58 g; P = .001). Even in bulkier disease models with HeyA8-luc cells, 1C1-mcMMAF treatment, compared with control treatment, caused regression of established tumors and increased survival of the mice (eg, 1C1-mcMMAF vs control, mean = 60.6 days vs 29.4 days; difference = 31.2 days, 95% CI = 27.6 to 31.2 days; P = .001). The antitumor effects of 1C1-mcMMAF therapy, in SKOV3ip1 tumors, for example, were statistically significantly related to decreased proliferation (eg, 1C1-mcMMAF vs control, mean = 44.1% vs 55.8% proliferating cells; difference = 11.7%, 95% CI = 2.45% to 20.9%; P = .01) and increased apoptosis of tumor cells (eg, 1C1-mcMMAF vs control, mean = 8.6% vs 0.9% apoptotic cells; difference = 7.7%, 95% CI = 3.8% to 11.7%; P < .001) and of mouse endothelial cells (eg, 1C1-mcMMAF vs control, mean 2.8% vs 0.4% apoptotic endothelial cells; difference = 2.4%, 95% CI = 1.4% to 4.6%; P = .034). CONCLUSION The 1C1-mcMMAF immunoconjugate had antitumor activity in preclinical models of ovarian carcinoma.
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Affiliation(s)
- Jeong-Won Lee
- Department of Gynecologic Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
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Kamat AA, Coffey D, Merritt WM, Nugent E, Urbauer D, Lin YG, Edwards C, Broaddus R, Coleman RL, Sood AK. EphA2 overexpression is associated with lack of hormone receptor expression and poor outcome in endometrial cancer. Cancer 2009; 115:2684-92. [PMID: 19396818 DOI: 10.1002/cncr.24335] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
BACKGROUND EphA2 is a tyrosine kinase receptor in the ephrin family that is implicated in oncogenesis and angiogenesis. The objective of the current investigation was to study the role of EphA2 in endometrial cancer and its relation to steroid hormone receptor expression. METHODS EphA2, estrogen receptor (ER), progesterone receptor (PR), and Ki-67 expression levels were evaluated using immunohistochemistry in 139 endometrioid endometrial carcinoma (EEC) samples and in 10 benign endometrial samples. Samples were scored by 2 investigators who were blinded to clinical outcome. The results were correlated with clinicopathologic characteristics using univariate and multivariate analysis. A P value <.05 was considered statistically significant. RESULTS High expression of EphA2 was detected in 48% of EEC samples versus 10% of benign samples. EphA2 overexpression was associated significantly with high disease stage (P = .04), high tumor grade (P = .003), increased depth of myometrial invasion (P = .05), low ER expression (P = .01), low PR expression (P = .006), and high Ki-67 expression (P = .04). Low ER and PR expression levels were associated with high tumor grade, positive lymph nodes, high Ki-67 expression, and high EphA2 expression. On univariate analysis of all patients, high EphA2 expression was associated significantly with shorter disease-specific survival (DSS) (P < .001). On multivariate analysis, age (P < .001), high disease stage (P = .002), and high EphA2 expression (P = .04) were independent predictors of poor DSS. CONCLUSIONS EphA2 overexpression was associated with aggressive phenotypic features in EEC and was associated inversely with ER and PR expression. Thus, EphA2 may be an important therapeutic target, especially in patients with hormone receptor-negative endometrial carcinoma.
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Affiliation(s)
- Aparna A Kamat
- Department of Gynecologic Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77230-1439, USA
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Wesa AK, Herrem CJ, Mandic M, Taylor JL, Vasquez C, Kawabe M, Tatsumi T, Leibowitz MS, Finke JH, Bukowski RM, Bruckheimer E, Kinch MS, Storkus WJ. Enhancement in specific CD8+ T cell recognition of EphA2+ tumors in vitro and in vivo after treatment with ligand agonists. THE JOURNAL OF IMMUNOLOGY 2008; 181:7721-7. [PMID: 19017961 DOI: 10.4049/jimmunol.181.11.7721] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The EphA2 receptor tyrosine kinase is an attractive therapeutic target that is commonly overexpressed on solid tumors, with the degree of overexpression associated with disease progression, metastatic potential, and poor prognosis. Agonistic mAbs or ligand (ephrinA1)-Fc fusion protein are capable of inducing EphA2 internalization and degradation, thereby (at least transiently) eliminating the influence of this oncoprotein. We and others have also shown that EphA2 contains multiple peptide epitopes that can be recognized by effector CD4(+) and CD8(+) T cells isolated from tumor-bearing patients. Herein, we show that "agonist" reagents that trigger the proteasome-dependent degradation of tumor cell EphA2 result in the improved presentation of peptides derived from (both the extracellular and intracellular domains of) EphA2 in MHC class I complexes expressed on the tumor cell membrane for at least 48 h, as manifested by increased recognition by EphA2-specific CD8(+) T cells in vitro. We also observed that while delivery of ephrinA1-Fc fusion protein or agonist mAb into EphA2(+) tumor lesions promotes EphA2 degradation in situ, this single administration of agent does not dramatically alter tumor progression in a humanized SCID model. However, when combined with the adoptive transfer of normally nontherapeutic (human) anti-EphA2 CD8(+) CTL, this dual-agent regimen results in complete tumor eradication. These results suggest that strategies targeting the conditional proteasome-mediated destruction of tumor cell EphA2 may enable EphA2-specific CD8(+) T cells (of modest functional avidity) to realize improved therapeutic potential.
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Affiliation(s)
- Amy K Wesa
- Department of Dermatology, University of Pittsburgh School ofMedicine, Pittsburgh, PA 15213, USA.
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Miao H, Wang B. Eph/ephrin signaling in epithelial development and homeostasis. Int J Biochem Cell Biol 2008; 41:762-70. [PMID: 18761422 DOI: 10.1016/j.biocel.2008.07.019] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2008] [Revised: 06/13/2008] [Accepted: 07/01/2008] [Indexed: 11/16/2022]
Abstract
Eph receptors and ephrin ligands are widely expressed during embryonic development with well-defined functions in directing neuronal and vascular network formation. Over the last decade, evidence has mounted that Ephs and ephrins are also actively involved in prenatal and postnatal development of epithelial tissues. Their functions beyond developmental settings are starting to be recognized as well. The diverse functions of Eph/ephrin are largely related to the complementary expression pattern of the Eph receptors and corresponding ephrin ligands that are expressed in adjacent compartments, although overlapping expression pattern also exists in epithelial tissue. The interconnection between Ephs or ephrins and classical cell junctional molecules suggests they may function coordinately in maintaining epithelial structural integrity and homeostasis. This review will highlight cellular and molecular evidence in current literature that support a role of Eph/ephrin systems in regulating epithelial cell development and physiology.
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Affiliation(s)
- Hui Miao
- Rammelkamp Center for Research, MetroHealth Campus, Case Western Reserve University School of Medicine, 2500 MetroHealth Drive, Cleveland, OH 44109, United States
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Wang L, Foster M, Zhang Y, Tschantz WR, Yang L, Worrall J, Loh C, Xu X. High yield expression of non-phosphorylated protein tyrosine kinases in insect cells. Protein Expr Purif 2008; 61:204-11. [PMID: 18602836 DOI: 10.1016/j.pep.2008.05.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2008] [Revised: 05/28/2008] [Accepted: 05/28/2008] [Indexed: 12/27/2022]
Abstract
The key role of kinases in signal transduction and cell growth regulation has been a long standing interest among academics and the pharmaceutical industry. Recombinant enzymes have been used to understand the mechanism of action as well as to screen for chemical inhibitors. The baculo-insect system has been the primary method used to obtain soluble and active kinases, usually producing a mixture of the kinase in various phosphorylation states in different conformations. To obtain a homogenous preparation of non-phosphorylated kinases is critical for biochemical, biophysical and kinetic studies aimed at understanding the mechanism of kinase activation. Taking advantage of the eukaryotic expression property of insect cells, we were able to obtain high yield expression of non-phosphorylated protein tyrosine kinases BTK, JAK3 and Eph2A through coexpression with the tyrosine phosphatase YopH, which suggests that this method can be applied to protein tyrosine kinases in general. We have demonstrated that the fully non-phosphorylated BTK obtained with this method is suitable for various biochemical and kinetic studies.
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Affiliation(s)
- Leyu Wang
- Research Technology Center, Pfizer Cambridge Laboratories, 620 Memorial Drive, Cambridge, MA 02139, USA.
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50
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Jin YJ, Wang J, Qiao C, Hei TK, Brandt-Rauf PW, Yin Y. A novel mechanism for p53 to regulate its target gene ECK in signaling apoptosis. Mol Cancer Res 2007; 4:769-78. [PMID: 17050670 DOI: 10.1158/1541-7786.mcr-06-0178] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Transcription factor p53 regulates its target genes through binding to DNA consensus sequence and activating the promoters of its downstream genes. The conventional p53 consensus binding sequence was defined as two copies of the 10-bp motif 5'-PuPuPuC(A/T)(T/A)GPyPyPy-3' with a spacer of 0 to 13 bp, which exists in the regulatory regions of some p53 target genes. However, there is no such p53 consensus sequence in the promoters of a number of p53-responsive genes, suggesting that there might be other mechanisms whereby p53 transactivates the promoters of its target genes. We report here that p53 uses a novel binding mechanism to regulate the transcription of epithelial cell kinase (ECK), a receptor protein-tyrosine kinase implicated in signal transduction. We show that p53 binds to a 10-bp perfect palindromic decanucleotide (GTGACGTCAC) in the ECK promoter, activates the ECK promoter, and increases the transcription of ECK. This palindrome is required for p53-mediated transactivation of the ECK promoter. ECK is highly responsive to oxidative damage that leads to cell death. Ectopic expression of ECK causes spontaneous apoptosis in breast cancer cells. We found that ectopic expression of a mutant ECK fails to induce apoptosis in cancer cells. Our findings show that p53 is a transcriptional regulator of ECK in mediating apoptosis. The discovery of the novel p53-binding motif in the promoter may lead to the identification of a new class of p53 target genes.
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Affiliation(s)
- Y Jenny Jin
- Department of Radiation Oncology College of Physicians and Surgeons, Columbia University, 630 West 168th Street, New York, NY 10032, USA
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