(PQB6)Elucidating metastasis by real-time monitoring and tagging of CTCs in GEMMs

描述（由申请人提供）：尽管循环肿瘤细胞（CTC）具有核心重要性，但由于CTC群体随时间变化的特征以及它们与自然肿瘤进展过程中发生的转移之间的联系极其困难，对其在转移中的作用的理解受到限制。我们建议开发一种新的系统，可以在基因工程小鼠模型（GEMMs）中进行纵向和动态CTC研究。该系统将使一系列实验成为可能，这些实验可以回答有关CTC特征与转移之间关系的基本问题：在肿瘤进展过程中，CTC在循环系统中停留的时间（半衰期）是否会改变？原发肿瘤中的癌细胞是否在开始后不久就易形成转移，或者肿瘤必须进化才能获得转移潜力？化疗或抗血管生成药物是否会促进CTC体内浸润并增加远处转移的可能性？除了这些基本问题的范围之外，开发一种能够在GEMMs中进行动态和纵向CTC研究的液体活检系统将增强假设驱动的肿瘤生物学研究和对患者不可行的治疗策略的大规模临床前探索。我们提出的系统将使用带有荧光报告器的小鼠，这些荧光报告器可以明亮地标记所有肿瘤细胞，包括手术安装的动静脉分流器；以及一种由真实计算机系统控制的微流控电池分选机。在手术中，活体小鼠的大部分血液将通过该系统并通过导管回流。每次荧光CTC通过分选器时，控制系统会将包括CTC在内的少量血液转移到收集端口，从而产生显着富集的CTC样本。样品可以用各种技术进一步浓缩和处理。

DESCRIPTION (provided by applicant): Despite the central importance of circulating tumor cells (CTCs), understanding of their role in metastasis has been limited by the extreme difficulty of characterizing CTC populations over time and linking them to metastases that occur during natural tumor progression. We propose to develop a novel system that enables longitudinal and dynamic CTC studies in genetically engineered mouse models (GEMMs). The system will make possible a series of experiments that can answer fundamental questions about the relationship between CTC characteristics and metastasis: Does the time that CTCs remain in the circulatory system (half-life) change during tumor progression? Are cancer cells in primary tumors predisposed to form metastases soon after initiation or must tumors evolve to acquire metastatic potential? Do chemotherapeutic or anti-angiogenic agents promote CTC intravasation and increase the likelihood of distant metastasis? Beyond the scope of these fundamental questions, developing a system that enables liquid biopsies for dynamic and longitudinal CTC studies in GEMMs will potentiate hypothesis-driven tumor biology studies and large-scale preclinical exploration of therapeutic strategies that are not feasible in patients. Our proposed system will use mice with fluorescent reporters that brightly label all tumor cells, including CTCs a surgically installed arterio-venous shunt; and a microfluidic cell sorter controlled by a real-tie computer system. In operation, the majority of blood from a live mouse will pass through the system and return via catheter. Each time a fluorescent CTC passes through the sorter, the control system will divert a small volume of blood including the CTC to a collection port, producing a dramatically enriched CTC sample. The sample can be further concentrated and manipulated by a variety of techniques.