Grhl2-regulation of Developing Ectoderm as a Model to Identify Suppressors of EMT

描述(申请人提供)：上皮到间充质(EMT)的转变在胚胎发育过程中起着至关重要的作用。研究还发现，EMT可以参与促进各种上皮性癌症的发生。最近的证据支持这样的观点，即发育和癌症之间的EMT过程在分子水平上是相似的。因此，使用体内发育系统来研究EMT是如何调控的，可能会识别出与人类癌症治疗相关的基因。在胚胎神经管关闭期间，神经脊细胞经历EMT，因为它们从神经外胚层剥离，迁移到远处。同时，相邻的非神经外胚层(NNE)细胞必须在同一上皮内保持紧密联系，才能正确地进行神经管关闭。人们对神经脊EMT的调控机制知之甚少，但对非神经性外胚层如何影响其上皮命运知之甚少。转录因子Graineyhead like 2(Grhl2)在神经管闭合过程中在NNE细胞中表达，并可能通过其直接的下游靶点作为EMT的抑制因子。事实上，GRHL2最近被证明在乳腺癌模型中以这种方式起作用。在神经管关闭时从胚胎中分离NNE，然后进行高通量RNA测序，从而识别出可能参与该组织中EMT抑制的几个基因。在这 在该项目中，将使用功能丧失的Grhl2小鼠模型(Grhl21Nisw/1Nisw)来探索这些基因在Grhl2调控的小鼠胚胎NNE中EMT抑制网络中的潜在作用。对这些基因的进一步评估将表明，在神经管关闭期间，基因功能丧失如何影响NNE细胞行为的动态。随后将在乳腺癌模型中进一步研究在发育中的神经管中发现的抑制EMT的基因，以确定它们是否既影响体外EMT又影响体内转移。通过这项研究，将进一步了解Grhl2调控的EMT抑制基因网络，并可能识别可能影响上皮癌进展的靶点。

DESCRIPTION (provided by applicant): The epithelial-to-mesenchymal (EMT) transition plays an essential role during embryonic development. Studies have also found that EMT can be involved in the promotion of various epithelial cancers. Recent evidence supports the idea that the EMT process between development and cancer is similar at the molecular level. Therefore, using an in vivo developmental system to study how EMT is regulated may identify genes that are relevant targets for treatment of human cancers. During embryonic neural tube closure, neural crest cells undergo an EMT as they delaminate out of the neuroectoderm to migrate to distant sites. At the same time, the neighboring non-neural ectoderm (NNE) cells must remain tightly associated within the same epithelium in order for neural tube closure to proceed correctly. Much is known about the regulatory mechanisms driving neural crest EMT, however less is known about how the non-neural ectoderm enforces its epithelial fate. The transcription factor Graineyhead like 2 (Grhl2) is expressed within the NNE cells during neural tube closure and may act as a suppressor of EMT via its direct downstream targets. In fact, GRHL2 has recently been shown to act in this manner in a breast cancer model. Isolation of NNE from embryos at the time of neural tube closure followed by high throughput RNA-sequencing led to the identification of several genes that may be involved in EMT suppression in this tissue. In this project, a loss of function Grhl2 mouse model (Grhl21Nisw/1Nisw) will be used to explore these genes for a potential role within a Grhl2-regulated network of EMT suppression in the NNE of the mouse embryo. Further assessment of these genes will show how loss of gene function affects the dynamics of NNE cell behavior during neural tube closure. Genes that are found to suppress EMT in the developing neural tube will then be further investigated in a breast cancer model to determine if they affect both in vitro EMT as well as in vivo metastasis. Through this study, a further understanding of a Grhl2- regulated gene network of EMT suppression will be gained and targets may be identified that could impact the progression of epithelial cancers.