Project 2: Mechanochemical Mechanisms and Vulnerabilities of Individual and Collective Organ-Preferential Metastasis In Vivo

项目2：总结 循环肿瘤细胞(CTCs)的器官定植和存活依赖于肿瘤中的反应程序 细胞(TC)，称为机械适应，以应对细胞质上的机械和分子压力。 胞核在血管内停滞和外渗过程中出现。的强度和持续时间 不同器官(如肝脏和皮肤)的血管床上的机械应力是不同的，而且 个体细胞和集体器官的定植。与机械适应有关的分子系统 CTC包括协调的细胞-细胞黏附、细胞骨架的收缩、蛋白水解酶系统和变形 或核，它们相互协作以确保进入次级部位的多步运动和TC的存活。我们 假设在体内的成功转移依赖于机械之间的适应性相互作用 和分子血管内和血管周围的应力存在于远端，CTC的应对能力 克服这些压力。通过协调细胞间的黏附、细胞骨架的收缩、变形 细胞核和蛋白水解酶系统我们预测，机械适应保护个体细胞和集体TC 存活并进一步调节朝向生长或休眠的持久重新编程。因此，我们 预计干扰细胞机械适应策略将增加细胞压力，支持CTC 死亡和减少转移性器官定植。通过在小鼠模型中结合活体显微镜， 计算建模(核心A)和转录和染色质结构分析(核心B)，我们将 解决三阴性乳腺癌单细胞和集体器官定植的限速步骤 皮肤和肝脏的黑色素瘤细胞。在目标1中，我们将研究集体和单细胞的机制 通过干扰黏附连接(p120-catenin)和 血管内凝血。在目标2中，我们将确定细胞骨架和核的限速步骤 在单细胞和集体器官定植期间重建血管壁的力学和能力。 靶向干扰CD44介导的与血管周围基质的黏附，肌球蛋白收缩能力， 核变形性受层蛋白A/C表达变化和基底膜重组能力的影响 将会被执行。在目标3中，我们将确定应激诱导的力学基础上的分子反应。 利用转录和超微结构研究核染色质构象的适应性及其相关效应 分析与计算建模相结合。确定了与中介机制有关的关键途径- 联合应用将抑制适应和TC存活、细胞周期停滞(休眠)和生长 分子干扰以限制TC存活以及单细胞和集体转移。这个项目将 提供关于细胞迁移、分子重新编程、命运决定的综合观点，并揭示潜力 干预点是为了增强转移过程中肿瘤细胞的清除。

Project 2: SUMMARY Organ colonization and survival of circulating tumor cells (CTCs) depends on a response program in tumor cells (TCs), termed mechano-adaptation, to cope with mechanical and molecular stresses on the cytoplasm and nucleus experienced during intravascular arrest and extravasation. The strength and duration of mechanical stress differs in vascular beds among organs, such as liver and skin, and further differs between individual-cell and collective organ colonization. Molecular systems implicated in the mechano-adaptation of CTCs include coordinated cell-cell adhesions, cytoskeletal contractility, protease systems and deformation or the nucleus, which cooperate to secure multistep movement into the secondary site and TC survival. We hypothesize that successful metastasis in vivo depends on an adaptive interplay between the mechanical and molecular intra- and perivascular stresses present at distant site and the coping ability of CTCs to overcome these stresses. By coordinated cell-cell adhesion, cytoskeletal contractility, deformation of the nucleus, and protease systems we predict that mechano-adaptation secures individual-cell and collective TC survival and further mediates lasting reprogramming towards growth or dormancy. Consequently, we anticipate that interfering with cell mechanical adaptation strategies will increase cell stress, support CTC death and diminish metastatic organ colonization. By combining intravital microscopy in mouse models, computational modeling (Core A) and transcriptomic and chromatin structure analyses (Core B), we will address the rate-limiting steps of single-cell and collective organ colonization of triple-negative breast cancer and melanoma cells to skin and liver. In Aim 1 we will examine the mechanisms of collective and single-cell organ colonization and metastatic outcomes, by interfering with adherens junctions (p120-catenin) and intravascular coagulation. In Aim 2, we will identify the rate-limiting steps of cytoskeletal and nuclear mechanics and the ability to remodel the vascular wall during single-cell and collective organ colonization. Targeted interference with CD44-mediated adhesion to perivascular substrate, actomyosin contractility, nuclear deformability by lamin A/C expression variation and the ability to reorganize the basement membrane will be performed. In Aim 3, we will identify the molecular responses underlying stress-induced mechano- adaptation and associated effects on nuclear chromatin conformation, using transcriptomic and ultrastructural analyses combined with computational modeling. Identified key pathways implicated in mediating mechano- adaptation and TC survival, cell cycle arrest (dormancy) and outgrowth will be inhibited by combined molecular interference to limit TC survival and both single-cell and collective metastasis. This project will deliver an integrated view on cell migration, molecular reprogramming, fate decisions, and reveal potential intervention points to enhance tumor cell elimination in transit.