Novel Genetic Models to Study the Role of DNp63 in Squamous Cell Carcinoma

描述（由申请人提供）：鳞状细胞癌（SCC）是最常见的皮肤恶性肿瘤之一，全球发病率不断上升，因此构成了严重的公共卫生问题。尽管到目前为止，已经深入研究了导致SCC发生和发展的潜在遗传和表观遗传事件，但尚未成功开发出针对这种潜在致命皮肤癌的预防或治疗策略。因此，迫切需要进行更多的研究，以更好地了解这种皮肤病的分子病因，并利用这些知识开发新的有效治疗方法。来自我们实验室和其他实验室的证据，以及来自癌症基因组图谱计划的大规模测序数据，强烈表明转录因子p63，特别是最普遍的Np63亚型，在SCC发展的早期阶段作为癌基因发挥作用。我们发现，转基因小鼠（Np63BG）皮肤中Np63的过表达会导致严重的表型，这些表型具有许多与早期SCC相关的潜在组织学、病理和分子特征。然而，我们目前关于Np63在SCC早期发挥作用的分子基础的知识仍然很少。因此，我们将利用Np63BG和Np63-GFP敲入小鼠，这两种小鼠都是在我们的实验室开发的，来解决两个重要的感兴趣的领域。首先，考虑到SCC中Np63水平升高，我们建议通过对Np63BG和Np63杂合小鼠进行两阶段皮肤化学致癌研究，实验评估该异构体在肿瘤发展早期的作用。从这种体内研究中获得的数据将建立Np63的致癌功能，并提供更好地理解Np63亚型在SCC发生和进展的早期阶段的特定作用，迄今为止由于缺乏Np63亚型特异性小鼠模型，这是不可能的。其次，我们建议在全基因组范围内确定Np63特异性靶基因和促进SCC发展的调控网络。为此，我们将进行染色质免疫沉淀（ChIP）和深度测序（ChIP-seq），以确定Np63的新的直接靶基因，这些基因在Np63BG小鼠皮肤中发生改变，可能有助于SCC的发展。总的来说，从这些遗传研究中收集到的信息不仅有可能显著增强我们对SCC潜在致病改变的分子理解，而且还可能为未来的治疗选择发现新的驱动途径和关键因素。

DESCRIPTION (provided by applicant): Squamous cell carcinoma (SCC) is one of the most common forms of skin malignancies with increasing global incidence, thus constituting a serious public health concern. Although to date the underlying genetic and epigenetic events contributing to the development and progression of SCC have been intensively studied, no resulting preventative or therapeutic strategies have been successfully developed to target this potentially lethal form of skin cancer. Therefore there is a vital need for additional studies to better understand the molecular etiology of this skin disease and harness that knowledge for the development of new and effective treatments. Evidence from our laboratory as well as others, together with the large-scale sequencing data emerging from the Cancer Genome Atlas Project, strongly suggest that the transcription factor p63, specifically the most prevalent Np63 isoforms, function as an oncogene in the early stages of SCC development. We show that overexpression of Np63 in transgenic mouse (Np63BG) skin results in a severe phenotype that share many of the underlying histological, pathological and molecular features associated with the early stages of SCC. However, our current knowledge regarding the molecular underpinnings through which Np63 functions in the early stages of SCC remains sparse. Hence, we will utilize Np63BG and Np63-GFP knock- in mice, both of which were developed in our laboratory, to address two important areas of interest. First, given the elevated levels of Np63 in SCC, we propose to experimentally evaluate the contribution of this isoform in the early stages of tumor development by performing two-stage skin chemical carcinogenesis studies on the Np63BG and Np63 heterozygous mice. Data obtained from such in vivo studies will establish the oncogenic function of Np63 and provide a better understanding of the specific role of the Np63 isoforms in the early stages of SCC initiation and progression, which to date have not been possible due to the lack of Np63 isoform specific mouse models. Secondly we propose to identify, on a genome-wide scale, Np63 specific target genes and regulatory networks contributing to the development of SCC. Towards this end, we will perform chromatin-immunoprecipitation (ChIP) followed by deep sequencing (ChIP-seq) to identify novel direct target genes of Np63, which are altered in the Np63BG mouse skin, and which likely contribute to the development of SCC. Collectively the information gleaned from these genetic studies has the potential to not only significantly enhance our molecular understanding of the underlying pathogenic alterations of SCC but also to unearth new driver pathways and critical players for future exploitation as therapeutic options.