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

描述(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，因此构成了一个严重的公共卫生问题。尽管到目前为止，对鳞状细胞癌发生和发展的潜在遗传和表观遗传事件进行了深入的研究，但还没有成功地开发出针对这种潜在致命形式的皮肤癌的预防或治疗策略。因此，迫切需要更多的研究来更好地了解这种皮肤病的分子病因学，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，有力地表明转录因子p63，特别是最普遍的Np63亚型，在鳞癌发展的早期阶段发挥癌基因的功能。我们发现，Np63在转基因小鼠(Np63BG)皮肤中的过表达导致了严重的表型，这种表型具有许多与鳞癌早期相关的潜在组织学、病理学和分子特征。然而，我们目前对Np63在鳞癌早期发挥作用的分子基础的了解仍然很少。因此，我们将利用我们实验室开发的Np63BG和Np63-GFP敲入小鼠来解决两个重要的感兴趣的领域。首先，考虑到鳞状细胞癌中Np63水平的升高，我们建议通过对Np63BG和Np63杂合子小鼠进行两阶段皮肤化学致癌研究，从实验上评估这种异构体在肿瘤发展早期的作用。从体内研究中获得的数据将确定Np63的致癌功能，并提供更好的了解Np63亚型在鳞状细胞癌启动和进展早期阶段的具体作用，由于缺乏Np63亚型特异性小鼠模型，迄今尚不可能实现这一点。其次，我们建议在全基因组范围内确定Np63特异的靶基因和调控网络，这些基因和网络有助于鳞癌的发展。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小鼠皮肤中发生变化，可能与鳞状细胞癌的发生有关。总的来说，从这些基因研究中收集到的信息不仅有可能显著增强我们对鳞癌潜在致病改变的分子理解，而且还可能发现新的驱动途径和关键角色，用于未来的治疗选择。

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.