Regulation of extracellular vesicle biogenesis through cell adhesion

摘要 转移是众所周知的癌症相关死亡的驱动因素。尽管如此， 靶向癌症转移，因为这是一个极其复杂的过程， 机制等Zijlstra和Weaver实验室的合作研究研究了细胞的两个独立方面 运动性：a）由粘附受体的蛋白水解脱落控制的细胞-细胞粘附的动力学，和B）由粘附受体的蛋白水解脱落控制的细胞-细胞粘附的动力学。 释放运动促进细胞外囊泡（EV）。由于这两个事件发生在同一个细胞中， 导致相同的表型，我们推测这两个生物过程是协调的。的确， 初步研究表明，syntenin-1是EV生物发生途径的关键组分，是 由IgG超家族成员活化白细胞粘附分子锚定的细胞粘附复合物 （ALCAM）及其伴侣-四跨膜蛋白CD 151。显著改变ALCAM的表达和/或脱落 影响了EV的生物发生，证实了我们最初的想法，即细胞-细胞粘附可以与EV协调 生物起源假设这是通过ALCAM和突触蛋白之间的细胞内联系发生的， 这进一步得到游离胞内结构域抑制EV生物发生的能力的支持。基于这些 观察和我们在细胞粘附，EV生物学和转移方面的专业知识，我们建议研究 在癌症进展过程中细胞粘附和促进运动性EV的产生之间的整合。 具体而言，拟开展的研究将探讨：1）细胞粘附和EV之间的机制整合 生物发生，2）并入促进运动性EV中的货物的后果，和3）功能性 有助于自分泌和旁分泌通信。此外，这种生物学的相关性将在 在膀胱癌的情况下，ALCAM脱落是生存的独立预后指标。为 为此，我们开发了一种新的膀胱尿路上皮和膀胱癌的离体器官型培养系统， 我们可以复制乳头状瘤和膀胱癌的临床表型的癌症。 考虑到肿瘤细胞有大量不同的机制可供其支配， 增强其恶性行为，决定细胞粘附和EV生物发生机制如何整合 不仅是一种去卷积复杂转移行为的创新方法， 冲击根据拟议研究的结果，将提供新的干预途径，其中治疗可能 以协同和一体化为目标，而不是直接采取行动。

Abstract Metastasis is a well-known driver of cancer-related deaths. Nevertheless, limited success has been achieved in targeting cancer metastasis because it is an exceedingly complex process driven by multiple, integrated mechanisms. Collaborative studies in the Zijlstra and Weaver laboratories studied two separate aspects of cell motility: a) the dynamics of cell-cell adhesion controlled by proteolytic shedding of adhesion receptor and b) the release of motility promoting extracellular vesicles (EV). Since these two events take place in the same cells and contributed to the same phenotype, we speculated that these two biological processes were coordinated. Indeed, preliminary studies demonstrated that syntenin-1, a key component of the EV biogenesis pathways, was part of a cell adhesion complex anchored by the IgG superfamily member Activated Leukocyte Cell Adhesion Molecule (ALCAM) and its companion-tetraspanin CD151. Altering the expression and/or shedding of ALCAM drastically impacted EV biogenesis, confirming our original idea that cell-cell adhesion could be coordinated with EV biogenesis. The hypothesis that this occurred through an intracellular link between ALCAM and syntenin is further supported by the ability of free intracellular domain to suppress EV biogenesis. Based on these observations and our published expertise in cell adhesion, EV biology and metastasis, we propose to investigate the integration between cell-adhesion and the production of motility-promoting EVs during cancer progression. Specifically, the proposed studies will investigate: 1) the mechanistic integration between cell-adhesion and EV biogenesis, 2) the consequences for cargo incorporated in motility-promoting EVs, and 3) the functional contribution to autocrine and paracrine communication. Moreover, the relevance of this biology will be tested in the context of bladder cancer where ALCAM shedding is an independent prognostic indicator of survival. For this purpose we have developed a novel ex vivo organotypic culture system for bladder urothelium and bladder cancer in which we can replicate the clinical phenotypes of both papilloma and carcinoma of the bladder. Considering that tumor cells have a large number of divergent mechanisms at their disposal by which they can enhance their malignant behavior, determining how mechanisms of cell adhesion and EV biogenesis integrate is not only an innovative way to deconvolve complex metastatic behavior, it will also have significant clinical impact. With findings from the propose studies, will provide novel avenues of intervention where a therapy may target a point of synergy and integration rather than a direct mode of action.