A large animal model to elucidate the role of LGR5 stem cells in cancer

项目摘要 在美国，结直肠癌(CRC)是女性癌症死亡的第三大原因， 男性加在一起，每年每20人中就有1人被诊断出患有结直肠癌。然而，理解因素 由于缺乏合适的动物模型，控制疾病的进展和转移一直受到阻碍 CRC。目前，关于在结直肠癌和结直肠癌中发生突变的候选基因的信息很多。 有助于肿瘤部位、肿瘤表型和患者对治疗的反应。而候选基因 可以利用携带功能获得和功能丧失基因的转基因品系在小鼠身上进行研究 APC等候选基因的修饰和突变会导致小鼠出现与表面上看起来不同的损伤 在人类身上。因此，需要对传统的转基因模型进行修改，以提高我们的 对CRC的理解。相比之下，类似的APC-/-PIG模型显示的主要是结肠癌， 它们与人类疾病惊人地相似。 我们建议将现有的经过基因编辑的LGR5-H_2B-GFP猪品系的优势与 Cre诱导的Cas9系统产生一种新的株系，将允许在体内和体外进行仔细的解剖 与LGR5细胞在结肠癌中的行为相关的分子通路。这项提议将允许 用于模型的生成和初步的体外和体内验证。 这个高度相关的大型动物模型将极大地提高我们对LGR5细胞行为的理解 在致癌转化过程中在分子水平上进行控制，将对开发新的 治疗人类结直肠癌以及其他癌症的策略。

Project Summary In the United States, colorectal cancer (CRC) is the 3rd leading cause of cancer death among women and men combined, with of 1 in 20 people being diagnosed with CRC each year. Yet, understanding factors controlling disease progression and metastasis has been hampered by the lack of a suitable animal model of CRC. At present, there is considerable information regarding candidate genes that are mutated in CRC and contribute to tumor locations, tumor phenotype and patient response to treatment1. While candidate genes can be studied in mice by use of transgenic lines carrying gain-of-function and loss-of function genetic modifications, mutations in candidate genes such as Apc, result in lesions in mice that differ from those seem in humans. As a result, modifications of the traditional transgenic model have been required to advance our understanding of CRC. In contrast, an analogous APC-/- pig model demonstrates predominantly colon tumors, which are remarkably similar to the human disease. We propose to combine the strengths of an existing gene edited LGR5-H2B-GFP pig line with the power of a Cre-inducible Cas9 system to generate a novel line that will allow a careful dissection both in vivo and in vitro of the molecular pathways associated with the behavior of LGR5 cells in colon cancer. This proposal will allow for the generation and the initial in vitro and in vivo validation of the model. This highly relevant large animal model will greatly improve our understanding of how LGR5 cells behavior is controlled at the molecular level during oncogenic transformation and will be of great use to develop novel strategies to treat human colorectal cancer, as well as other cancers.