Organoid modeling of pre-metastatic niche formation in the liver by primary colorectal tumor secreted factors

转移性疾病仍然是癌症相关死亡的主要原因。在结直肠癌(CRC)中，肝脏 转移的原发部位；大多数被诊断为结直肠癌的患者死于他们的肝脏 转移瘤。这为研究复杂的转移机制提供了强大的动力。 瀑布，希望导致新的干预方法。然而，对生物机制的研究 导致转移性疾病的因素一直很难。最近兴起的研究的一个这样的目标是 转移前生态位(PMN)，形成于远离原发肿瘤，但创造有利环境 让转移细胞站稳脚跟。研究PMN是具有挑战性的，因为在动物模型中几乎是不可能的 要预测PMN何时可能发生变化，并在确定转移后，为时已晚。一个 临床相关的体外模型，在该模型中转移和导致转移的组织的变化可以 观察和操纵将是探索这些机制和识别 绕过它们的方法。我们的团队现在已经发表了几篇论文，描述了我们在体外进行的生物工程 由微流控设备和3D细胞外基质(ECM)组成的芯片上转移(MOC)平台 水凝胶为基础的肿瘤和组织器官。我们的目标是使用这些工具及早识别和定位 主要肿瘤分泌介质对肝脏中性粒细胞的影响及其作用 与结直肠癌转移有关。我们将通过使用3D肝脏、CRC和骨髓造血来实现这一点 祖细胞(BM-HPC)类有机物，包含在微流控平台中，用于量化肝脏重塑和BM- HPC的重新募集，以及这种重塑如何影响体外转移的可能性和动力学。 我们假设在我们新的生物工程体外平台中，从肿瘤细胞系分泌的介质 不同级别的有机化合物和患者来源的肿瘤有机化合物(PTO)会诱导相应的光谱 ECM重塑、建筑失调和BM-HPC招募，这些因素在增强时，对应于 转移增加。在目标1中，我们将对原代人肝和BM-HPC有机物进行CRC 条件培养液，测量肝间质(星状)和免疫(Kupffer)细胞的激活，并定量ECM 在成分、建筑和机械性能方面的重塑。作为这个目标的一部分，我们将剖析 得出星状细胞、Kupffer细胞和BM-HPC对这些变化的相对贡献。在《目标2》中，我们的MOC 除了肝脏和BM-HPC有机物质外，设备还将包括肿瘤有机物质，我们将评估PMN 在这个动态的多组织平台上形成。从肿瘤到肝脏器官的转移将被测量。 这将使我们能够将PMN的变化与转移事件联系起来。最终，这些研究将提供 有机会确定肿瘤细胞分泌的介质和PMN的独特特征，这些特征可能 在变得不可治愈之前，作为早期转移过程的未来靶点，以及 预测患者的转移。

Metastatic disease remains the primary cause of cancer-related deaths. In colorectal cancer (CRC), the liver is the primary site of metastases; and, the majority of patients diagnosed with CRC die as a result of their hepatic metastases. This provides a powerful motivation to study the mechanisms behind the complicated metastatic cascade, hopefully leading to novel approaches for intervention. However, studying the biological mechanisms that contribute to metastatic disease has been difficult. One such target for research that has arisen recently is the pre-metastatic niche (PMN), which forms distant from the primary tumor, but creates favorable environments for metastasizing cells to take hold. Studying the PMN is challenging, as in animal models it is nearly impossible to predict when changes might happen in the PMN, and after identification of metastases, it is too late. A clinically-relevant in vitro model in which metastasis and the changes to tissues leading up to metastasis can be observed and manipulated would be an invaluable resource for probing these mechanisms and for identifying ways to circumvent them. Our team has now published several papers describing our bioengineered in vitro metastasis-on-a-chip (MOC) platform that is comprised of microfluidic devices and 3D extracellular matrix (ECM) hydrogel-based tumor and tissue organoids. Our objective is to use these tools to identity and pinpoint early changes to the liver PMN that occur because of primary tumor-secreted mediators and assess their contributions to CRC metastasis. We will accomplish this by employing 3D liver, CRC, and bone marrow hematopoietic progenitor cell (BM-HPC) organoids, contained in a microfluidic platform to quantify liver remodeling and BM- HPC recruitment, and in turn, how this remodeling influences the likelihood and kinetics of in vitro metastasis. We hypothesize that within our novel bioengineered in vitro platform, secreted mediators from tumor cell line organoids and patient-derived tumor organoids (PTOs) of varying grade will induce a corresponding spectrum of ECM remodeling, architectural dysregulation, and BM-HPC recruitment, which when heightened, corresponds with increased metastasis. In Aim 1, we will subject primary human liver and BM-HPC organoids to CRC conditioned media, measure hepatic stromal (stellate) and immune (Kupffer) cell activation, and quantify ECM remodeling in terms of composition, architecture, and mechanical properties. As part of this aim, we will dissect out the relative contributions of stellate cells, Kupffer cells, and BM-HPCs to these changes. In Aim 2, our MOC device will include tumor organoids in addition both the liver and BM-HPC organoids and we will assess PMN formation in this dynamic multi-tissue platform. Metastasis from the tumor to liver organoid will be measured. This will enable us to link changes of the PMN to metastatic events. Ultimately, these studies will provide opportunities to identify tumor cell secreted mediators and distinct features of the PMN that could potentially serve as future targets of the early metastatic process prior to becoming incurable as well as biomarkers for prediction of metastasis in patients.