Cell fate decisions in Merkel cell carcinoma initiation and maintenance

默克尔细胞癌发生和维持的细胞命运决定

基本信息

批准号：
10549793
负责人：
ANDRZEJ A. DLUGOSZ
金额：
$ 51.44万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-02-20 至 2025-01-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10549793
关键词：
Adult Aggressive behavior Alleles Antigen Targeting Antigens Behavior Biological Cancer Etiology Cancer Model Cell Line Cell Lineage Cells Collection Coupled Development Doxycycline Genetically Engineered Mouse Grant Growth Human Immune Large T Antigen Maintenance Malignant Epithelial Cell Malignant Neoplasms Merkel Cells Merkel cell carcinoma Messenger RNA Modeling Molecular Mus Neuroendocrine Cell Neuroendocrine Tumors Neurosecretory Systems Pathogenesis Phenotype Play Polyomavirus Polyomavirus Transforming Antigens Pre-Clinical Model Production Proliferating Property Resistance Role Skin Skin Cancer Small T Antigen Suspensions TP53 gene Testing Touch sensation Transcript Transplantation Variant Viral Viral Oncogene Virus Work candidate identification cell type cellular engineering epidermal stem cell experimental study in vivo inducible Cre insight keratinocyte knock-down loss of function mouse model neoplastic cell neuroendocrine phenotype novel strategies postmitotic progenitor stem cells transcription factor transcriptome transgene expression tumor tumor progression tumorigenesis tumorigenic

项目摘要

Merkel cell carcinoma (MCC) is a rare and aggressive neuroendocrine skin cancer that frequently carries an integrated copy of Merkel cell polyomavirus (MCPyV) and expresses viral transforming antigens (TAgs) that likely play a key role in tumorigenesis. MCC tumor cells also express transcripts detected in normal, post- mitotic Merkel cells residing in skin, including a set of mRNAs encoding lineage-specific transcription factors implicated in neuroendocrine cell fate. Work from our lab and others established that MCPyV small T antigen (sTAg), +/- truncated large T antigen (tLTAg), is sufficient to drive transformation in vivo, but MCC-like tumors were not detected in any of these models despite TAg targeting to various potential tumor progenitor. The lack of a viable mouse model of MCC has been a major impediment to progress in this field. Normal Merkel cells arise from epidermal progenitors in specialized cellular compartments called touch domes, but the cell of origin of MCC is unknown. In an effort to override the apparent resistance of multiple cell types to MCPyV TAg-driven MCC development in genetically-engineered mice, we generated mice co- expressing the Merkel cell transcription factor Atoh1, together with MCPyV TAgs, in epidermal keratinocytes. These mice developed small collections of proliferating MCC-like tumor cells, and when coupled with deletion of one copy of p53, yielded gross tumors strikingly similar to human MCCs based on multiple criteria. Given the pivotal role of Atoh1 in MCC tumorigenesis we performed complementary loss-of-function studies, and discovered that Atoh1 knock-down converts human MCC cells from their typical neuroendocrine phenotype and growth in suspension, to cells with adherent growth, loss of neuroendocrine markers, and more aggressive behavior in vivo. We thus hypothesize that Atoh1 and other transcription factors governing Merkel cell fate play a pivotal role in MCC pathogenesis as well as maintenance of the neuroendocrine tumor phenotype. We propose the following aims to test this hypothesis. 1) Generate and characterize MCC-like tumors driven by MCPyV TAg expression targeted to candidate MCC progenitor cells. 2) Determine whether MCPyV TAg expression is required for mouse MCC maintenance. 3) Examine the role of Merkel cell lineage transcription factors in governing neuroendocrine cell fate and biological behavior of human MCC cell lines. These studies will yield new insights into the molecular basis of MCC and validate a much-needed mouse model of MCC.

默克尔细胞癌（MCC）是一种罕见而侵略性的神经内分泌皮肤癌，经常带有默克尔细胞多瘤病毒（MCPYV）的综合副本，并表达病毒转化抗原（TAG）可能在肿瘤发生中起关键作用。 MCC肿瘤细胞还表达在正常的，后期检测到的转录本属于皮肤中的有丝分裂默克尔细胞，包括一组编码谱系特异性转录因子的mRNA 与神经内分泌细胞命运有关。我们实验室和其他人的工作确定了McPyv小型抗原（雄鹿），+/-截断的大T抗原（TLTAG）足以在体内驱动转化，但MCC样尽管标签靶向各种潜在的肿瘤祖细胞，但在任何这些模型中均未检测到肿瘤。缺乏可行的MCC小鼠模型一直是该领域进步的主要障碍。正常的默克尔细胞来自专门的细胞室中的表皮祖细胞，称为触摸圆顶，但MCC的起源细胞尚不清楚。为了覆盖倍数的明显抵抗力细胞类型对基因工程小鼠的MCPYV TAG驱动的MCC发育，我们产生的小鼠共同表皮角质形成细胞中表达默克尔细胞转录因子ATOH1以及MCPYV标签。这些小鼠出现了少量的增殖MCC样肿瘤细胞，当与缺失结合时根据多个标准，一份P53副本的总肿瘤与人MCC非常相似。给出 ATOH1在MCC肿瘤发生中的关键作用我们进行了互补的功能丧失研究，并且发现ATOH1敲除了从其典型的神经内分泌表型中转化人MCC细胞悬浮液的生长，对具有依从性生长的细胞，神经内分泌标记的丧失以及更具侵略性体内行为。因此，我们假设ATOH1和其他控制默克尔细胞命运的转录因子起着关键作用在MCC发病机理以及神经内分泌肿瘤表型的维持中。我们建议以下目的是检验这一假设。 1）生成和表征由MCPYV标签驱动的MCC样肿瘤针对候选MCC祖细胞的表达。 2）确定MCPYV TAG表达式是否为鼠标MCC维护所需。 3）检查默克尔细胞谱系转录因子在人类MCC细胞系的神经内分泌细胞命运和生物学行为。这些研究将产生对MCC的分子基础的新见解并验证了MCC的急需的小鼠模型。