(PQB6) Genetics of Subclonal Evolution in Pancreatic Cancer

描述（由申请人提供）：转移导致90%的实体瘤癌症死亡。 尽管如此，与致癌、细胞通路失调或治疗耐药性相比，转移形成的机制相对研究不足。 有理由认为，转移的重点研究通过确定治疗发展的方面提供了提高生存率的机会。 该提案将解决挑衅性问题组B-6，“鉴于研究转移的困难，我们能否开发新的方法，如工程组织移植，以研究肿瘤扩散的生物学？“这一提议的假设是，原发性癌中的亚克隆遗传进化选择了促生存表型，这些表型的结果是转移。 我们提出了三个迭代目标来解决我们的假设。 在我们的第一个目标中，我们将确定亚克隆进化在多大程度上产生肿瘤内的遗传异质性和原发部位内的转移性亚克隆。 为此，我们将应用原发性和转移性组织的深度测序来确定转移的遗传基础，并结合克隆进化的计算建模。 在我们的第二个目标中，我们将确定在胰腺癌进展过程中亚克隆进化非随机选择特定基因或途径的程度。 这一目标将依赖于测序文库的生物信息学分析，以确定在肿瘤进展中具有重要意义的核心途径，以及基于使用各种模型确定的基因和核心途径的转移形成机制研究。 在我们的第三个目标中，我们将确定非遗传因素如EMT、致癌基质信号传导或免疫浸润在多大程度上与转移性亚克隆发展中的亚克隆进化相关。 这一目标将依赖于转移性亚克隆的无偏表达分析与高通量生物标志物筛选。 这一提议的预期总体影响将是其可能导致我们对肿瘤进展和转移的遗传基础的理解发生范式变化，并确定亚克隆进化一贯靶向的核心途径和功能。 了解这一点对于设计靶向转移表型并考虑遗传异质性的疗法的最终目标是重要的，而不是靶向迄今为止几乎没有显示出优势的特定基因。

DESCRIPTION (provided by applicant): Metastasis is responsible for 90% of cancer deaths from solid tumors. Despite this reality, the mechanisms of metastasis formation are relatively understudied compared to that of carcinogenesis, deregulation of cellular pathways, or treatment resistance. It stands to reason that focused studies of metastasis provide opportunities to improve survival by identifying aspects for therapeutic development. This proposal will address Provocative Question Group B-6, "Given the difficulty of studying metastasis, can we develop new approaches, such as engineered tissue grafts, to investigate the biology of tumor spread?" The hypothesis of this proposal is that subclonal genetic evolution within a primary carcinoma selects for prosurvival phenotypes, and the consequence of these phenotypes is metastasis. We propose three iterative Aims to address our hypothesis. In our first aim, we will determine the extent to which subclonal evolution generates intratumoral genetic heterogeneity and metastatic subclones within the primary site. For this aim we will apply deep sequencing of primary and metastatic tissues to determine the genetic basis of metastasis, in association with computational modeling of clonal evolution. In our second aim, we will determine the extent to which subclonal evolution nonrandomly selects for specific genes or pathways during pancreatic cancer progression. This aim will rely upon bioinformatics analyses of sequencing libraries to identify core pathways of significance in tumor progression, coupled with mechanistic studies of metastasis formation based on genes and core pathways identified using a variety of models. In our third aim, we will determine the extent to which non-genetic factors such as EMT, oncogenic stromal signaling or immune infiltration correlates with subclonal evolution in the development of metastatic subclones. This aim will rely on unbiased expression analyses of metastatic subclones in association with high-throughput biomarker screening. The expected overall impact of this proposal will be its potential to cause a paradigm change in our understanding of the genetic basis of tumor progression and metastasis, and to identify the core pathways and functions consistently targeted by subclonal evolution. This is important to know for the ultimate goal of devising therapies that target the metastatic phenotype and that take genetic heterogeneity into account, rather than targeting of specific genes that has shown little advantage thus far.