Role of a new polyomavirus in Merkel cell carcinoma

一种新的多瘤病毒在默克尔细胞癌中的作用

• 批准号: 7652877
• 负责人: PATRICK S. MOORE
• 金额: $ 45.51万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-03-13 至 2014-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7652877
• 关键词: Affinity Chromatography; Antibodies; Antigen Targeting; Binding; Binding Proteins; Biological Assay; Biological Models; Blood Cells; Breeding; C-terminal; Cell Line; Cells; Cercopithecus pygerythrus; Classification; Detection; Enhancers; Epidemiology; Fluorescent in Situ Hybridization; Gene Expression; Generations; Genome; Germany; Human; Immunoblotting; Immunoprecipitation; In Vitro; Insertional Mutagenesis; Introns; Japan; Knockout Mice; Learning; Luciferases; Malignant Epithelial Cell; Malignant Neoplasms; Mechanoreceptor Cell; Merkel Cells; Merkel cell carcinoma; Mus; Mutation; N-terminal; Oncogene Proteins; PTPRG gene; Patients; Pattern; Persons; Plasmids; Play; Polyomavirus; Polyomavirus Infections; Population; Preclinical Drug Evaluation; Prevention; Production; Protein Binding Domain; Protein C; Protein Tyrosine Phosphatase; Proteins; Proteomics; Reporter; Retinoblastoma Protein; Rodent; Role; Signal Transduction; Simian virus 40; Site; Skin Cancer; Soft Agar Assay; Southern Blotting; TP53 gene; Transgenic Mice; Tumor Suppressor Proteins; Tumor-Derived; Viral Tumor Antigens; Virus; Virus Diseases; Virus Integration; advanced disease; carcinogenesis; cell transformation; novel; public health relevance; receptor; research study; sialosyl-T antigen; tumor; tumorigenesis

DESCRIPTION (provided by applicant): We have recently discovered a new human polyomavirus monoclonally-integrated into human Merkel cell carcinomas (MCC) that we call Merkel cell polyomavirus (MCPyV). MCC is a rare neuroectodermal cancer suspected to be caused by a viral infection because of its unusual epidemiology. It is the most aggressive skin cancer and only 50% of patients with advanced disease survive 9 months or longer. MCPyV has a 5.4 kbase genome closely related to murine and African green monkey lymphotropic polyomaviruses (MuPyV and LPyV, respectively). MCPyV is distantly related to SV40 and the four known human polyomaviruses. Human serosurveys show that 15-30% of populations from the US, Japan and Germany have cross-reactive antibodies to LPV which may actually represent reactivity to MCPyV infection. We find similar MCPyV infection rates using direct detection of MCPyV genome from peripheral blood cells. If confirmed, these findings suggest that over a billion persons have been exposed to MCPyV infections worldwide. Southern blotting shows that MCPyV is integrated into MCC genome at different sites in a somatic and monoclonal pattern. One cellular integration site has been defined as the receptor-type protein tyrosine phosphatase-gamma (PTPRG) intron 1. MCPyV also expresses a highly conserved T antigen in tumors. The N-terminus of MCPyV encodes transformation-associated DnaJ and LXCXE pocket protein-binding domains. All tumor- derived MCPyV T antigens, however, possess T antigen mutations that eliminate T antigen origin binding and/or plasmid replication functions. These functions are not needed to maintain integrated virus, suggesting that MCC arises in at least two steps: first, MCPyV integrates into the host genome; second, truncation mutations arise allowing expression of N-terminal transforming domains, but eliminating deleterious C- terminal domains. MCPyV may play a role in tumorigenesis through insertional mutagenesis, expression of T antigen or both. Our proposal seeks to understand these mechanisms for transformation and oncogenesis by 1) identifying additional cell integration sites, 2) analyzing T antigen transforming functions in rodent cells and in cell signaling assays, 3) performing cell-wide proteomic analysis following T antigen expression, 4) identifying novel cellular T antigen direct interactors and 5) generating transgenic mice with MCPyV T antigen expression targeted to Merkel mechanoreceptor cells. Through this systematic approach we anticipate we will learn how this new virus contributes to human carcinogenesis. PUBLIC HEALTH RELEVANCE: This proposal seeks to understand how Merkel cell virus (MCV) contributes to human cancers. MCV has been found as an integrated virus in Merkel cell carcinoma where it expresses T antigen, an oncoprotein that has been well-characterized from closely-related viruses. This proposal will investigate similarities and differences between MCV T antigen and T antigen from other viruses as well as dysregulation of cellular proteins from MCV integration and T antigen expression. Finally, we seek to generate a model system for MCV tumorigenesis that will be useful for drug screening and prevention.

描述（由申请人提供）：我们最近发现了一个新的人类多瘤病毒单次融合到人类默克尔细胞癌（MCC）中，我们称之为Merkel细胞多瘤病毒（MCPYV）。 MCC是一种罕见的神经外科癌，涉嫌由于其异常流行病学而引起的病毒感染引起。它是最具侵略性的皮肤癌，只有50％的晚期疾病患者生存9个月或更长时间。 MCPYV的基因组与鼠和非洲绿色猴子淋巴细胞病毒（分别为mupyv和lpyv）密切相关。 MCPYV与SV40和四个已知的人类多瘤病毒遥远相关。人类血清疗法表明，来自美国，日本和德国的人群中有15-30％具有与LPV的交叉反应抗体，这实际上可能代表了对MCPYV感染的反应性。我们发现，使用直接检测到外周血细胞MCPYV基因组的MCPYV感染率相似。如果得到证实，这些发现表明，超过十亿人已经接触到全球MCPYV感染。 Southern印迹表明，MCPYV以体细胞和单克隆模式在不同位置的MCC基因组集成到MCC基因组中。一个细胞整合位点已被定义为受体型蛋白酪氨酸磷酸酶 - γ（PTPRG）内含子1。MCPYV也表达了肿瘤中高度保守的T抗原。 MCPYV的N末端编码与转化相关的DNAJ和LXCXE袖珍蛋白结合结构域。然而，所有肿瘤衍生的MCPYV T抗原均具有T抗原突变，可消除T抗原起源结合和/或质粒复制功能。这些功能不需要维持积分病毒，表明MCC至少在两个步骤中产生：首先，MCPYV集成到宿主基因组中；其次，会出现截短突变，允许表达N末端转化结构域，但消除了有害的c末端结构域。 MCPYV可能通过插入诱变，T抗原或两者的表达在肿瘤发生中起作用。我们的建议试图通过1）确定其他细胞整合位点来理解这些机制，以转化和肿瘤发生，2）分析啮齿动物细胞中的T抗原转化功能和细胞信号测定中的T抗原转化功能，3）3）在T抗原表达中执行细胞范围的蛋白质组学分析，4）与新型细胞T抗原相互作用的靶向Mers Merk and Merk and Mers contertor and Merk and Mcy contrular contigen contertor and Mcy toster contigent and Merk contigent and Merk contigent and Merk contigent and Merk contigent and M. 5）机械感受器细胞。通过这种系统的方法，我们预计我们将学习这种新病毒如何促进人类致癌作用。公共卫生相关性：该提案旨在了解默克尔细胞病毒（MCV）如何对人类癌症做出贡献。 MCV在默克尔细胞癌中被发现为一种综合病毒，在该病毒中，它表达了T抗原，T抗原是一种已从密切相关病毒中充分表征的癌蛋白。该建议将研究其他病毒中MCV T抗原和T抗原之间的相似性和差异，以及MCV整合和T抗原表达的细胞蛋白失调。最后，我们试图为MCV肿瘤发生生成模型系统，该系统对药物筛查和预防非常有用。